zx200 240 270 PDF
zx200 240 270 PDF
zx200 240 270 PDF
GENERAL
―CONTENTS―
Group 1 Specifications
Specifications ...........................................T1-1-1
Working Ranges.......................................T1-1-4
1V1T-1-1
(Blank)
1V1T-1-2
GENERAL / Specifications
SPECIFICATIONS
ZAXIS200-3
T1V1-01-01-006
Model ZAXIS200-3
Type of Front-End Attachment 2.91 m (9 ft 7 in) Arm
Bucket Capacity (Heaped) PCSA 0.8 m3 (1.05 yd3), CECE 0.7 m3
Operating Weight 19800 kg (43700 lb)
Basic Machine Weight 15400 kg (34000 lb)
Isuzu AH-4HK1XYSA-02
Engine
122 kW/2000 min–1 (166 PS/2000 rpm) (HP Mode)
A: Overall Width
2800 mm (9 ft 2 in)
(Excluding back mirrors)
B: Cab Height 2950 mm (9 ft 8 in)
C: Rear End Swing Radius 2750 mm (9 ft 0 in)
D: Minimum Ground Clearance * 450 mm (18 in)
E: Counterweight Clearance * 1030 mm (3 ft 5 in)
F: Engine Cover Height * 2270 mm (7 ft 5 in)
G: Overall Width of Upperstructure 2710 mm (8 ft 11 in)
H: Undercarriage Length 4170 mm (13 ft 8 in)
I: Undercarriage Width 2800 mm (9 ft 2 in)
J: Sprocket Center to Idler Center 3370 mm (11 ft 1 in)
K: Track Shoe Width 600 mm (24 in) (Grouser shoe)
Ground Pressure 44 kPa (0.45 kgf/cm2, 6.4 psi)
Swing Speed 13.3 min–1 (rpm)
Travel Speed (fast/slow) 5.5/3.5 km/h (3.4/2.2 mph)
Gradeability 35° (tanθ = 0.70)
NOTE: “*” The dimensions do not include height of the shoe lug.
T1-1-1
GENERAL / Specifications
ZAXIS240-3
T1V1-01-01-001
Model ZAXIS240-3
Type of Front-End Attachment 2.96 m (9 ft 9 in) Arm
Bucket Capacity (Heaped) PCSA 1.0 m3 (1.3 yd3), CECE 0.9 m3
Operating Weight 23400 kg (51600 lb)
Basic Machine Weight 17800 kg (39200 lb)
Isuzu AH-4HK1XYSA-01
Engine
132 kW/2000 min–1 (180 PS/2000 rpm)
A: Overall Width
2990 mm (9 ft 10 in)
(Excluding back mirrors)
B: Cab Height 3010 mm (9 ft 11 in)
C: Rear End Swing Radius 2940 mm (9 ft 8 in)
D: Minimum Ground Clearance *460 mm (18 in)
E: Counterweight Clearance * 1090 mm (3 ft 7 in)
F: Engine Cover Height * 2425 mm (7 ft 12 in)
G: Overall Width of Upperstructure 2890 mm (9 ft 6 in)
H: Undercarriage Length 4260 mm (13 ft 12 in)
I: Undercarriage Width 2990 mm (9 ft 10 in)
J: Sprocket Center to Idler Center 3463 mm (11 ft 4 in)
K: Track Shoe Width 600 mm (24 in) (Grouser shoe)
Ground Pressure 51 kPa (0.52 kgf/cm2, 7.4 psi)
Swing Speed 13.5 min–1 (rpm)
Travel Speed (fast/slow) 5.5/3.4 km/h (3.4/2.1 mph)
Gradeability 35° (tanθ = 0.70)
NOTE: “*” The dimensions do not include height of the shoe lug.
T1-1-2
GENERAL / Specifications
ZAXIS270-3
T1V1-01-01-003
Model ZAXIS270-3
Type of Front-End Attachment 3.11 m (10 ft 2 in) Arm
Bucket Capacity (Heaped) PCSA 1.1 m3 (1.44 yd3), CECE 1.0 m3
Operating Weight 27300 kg (60200 lb)
Basic Machine Weight 21300 kg (47000 lb)
Isuzu AH-4HK1XYSA-03
Engine
140 kW/2100 min–1 (190 PS/2150 rpm)
A: Overall Width
3190 mm (10 ft 6 in)
(Excluding back mirrors)
B: Cab Height 3100 mm (10 ft2 in)
C: Rear End Swing Radius 2940 mm (9 ft 8 in)
D: Minimum Ground Clearance *510 mm (20 in)
E: Counterweight Clearance *1180 mm (3 ft 11 in)
F: Engine Cover Height *2515 mm (8 ft 3 in)
G: Overall Width of Upperstructure 2890 mm (9 ft 6 in)
H: Undercarriage Length 4670 mm (15 ft 4 in)
I: Undercarriage Width 3190 mm (10 ft 6 in)
J: Sprocket Center to Idler Center 3728 mm (12 ft 3 in)
K: Track Shoe Width 600 mm (24 in) (Grouser shoe)
Ground Pressure 55 kPa (0.56 kgf/cm2, 8.0 psi)
Swing Speed 12.6 min–1 (rpm)
Travel Speed (fast/slow) 5.5 / 3.3 km/h (3.4 / 2.1 mph)
Gradeability 35° (tanθ = 0.70)
NOTE: “*” The dimensions do not include height of the shoe lug.
T1-1-3
GENERAL / Specifications
WORKING RANGES
ZAXIS200-3
T1V1-01-01-002
Model ZAXIS200-3
2.91 m (9 ft 7 in)
Category 2.42 m (7 ft 11in) Arm 2.91 m (9 ft 7 in) Arm
Arm + 1.5 EX Arm
Item
mm ftxin mm ftxin mm ftxin
NOTE: The dimensions do not include height of the shoe lug (except Item E).
T1-1-4
GENERAL / Specifications
T1V1-01-01-002
Model ZAXIS240-3
Category 2.19 m ( 7 ft 3 in) Arm 2.5 m (8 ft 2 in) Arm 2.96 m (9 ft 9 in) Arm 3.61 m (11 ft 10 in) Arm
Item mm ftxin mm ftxin mm ftxin mm ftxin
A: Maximum Digging Reach 9660 31’8” 9880 32’5” 10290 33’9” 10910 35’10”
B: Maximum Digging Depth 6190 20’4” 6500 21’4” 6960 22’10” 7610 24’12”
C: Maximum Cutting Height 10000 32’10” 9950 32’8” 10160 33’4” 10560 34’8”
D: Maximum Dumping Height 6970 10’’4” 6990 22’11” 7200 23’8” 7580 24’10”
E: Transport Height 3340 11’11” 3370 11’1” 3070 10’1” 3320 10’11”
F: Overall Transport Length 10240 33’7” 10270 33’8” 10150 33’4” 10200 33’6”
G: Minimum Swing Radius 3580 11’9” 3480 11’5” 3440 11’3” 3430 11’3”
NOTE: The dimensions do not include height of the shoe lug (except Item E).
T1-1-5
GENERAL / Specifications
T1V1-01-01-004
Model ZAXIS270-3
Category 2.42 m (7 ft 11 in) Arm 3.11 m (10 ft 2 in) Arm 3.76 m (12 ft 4 in) Arm
Item mm ftxin mm ftxin mm ftxin
NOTE: The dimensions do not include height of the shoe lug (except Item E).
T1-1-6
GENERAL / Specifications
T1V1-01-01-005
Model ZAXIS240-3
Category 2.19 m ( 7 ft 3 in) Arm 2.5 m (8 ft 2 in) Arm 2.96 m (9 ft 9 in) Arm 3.61 m (11 ft 10 in) Arm
Item mm ftxin mm ftxin mm ftxin mm ftxin
A: Maximum Digging Reach 9770 32’1” 10010 32’10” 10430 34’3” 11070 36’4”
B: Maximum Digging Depth 5810 19’1” 6080 19’11” 6530 21’5” 7190 23’7”
C: Maximum Cutting Height 11300 37’1” 11470 37’8” 11840 38’10” 12420 40’9”
D: Maximum Dumping Height 8210 27’1” 8350 27’5” 8720 28’7” 9300 30’6”
E: Transport Height 3150 10’4” 3200 10’6” 3090 10’2” 3340 10’12”
F: Overall Transport Length 10230 33’7” 10250 33’8” 10220 33’6” 10190 33’5”
G: Minimum Swing Radius 2500 8’2” 2560 8’5” 2310 7’7” 2610 8’7”
NOTE: The dimensions do not include height of the shoe lug (except Item E).
T1-1-7
GENERAL / Specifications
T1V1-01-01-005
Model ZAXIS270-3
Category 2.42 m (7 ft11 in) Arm 3.11 m (10 ft 2 in) Arm 3.76 m (12 ft 4 in) Arm
Item mm ftxin mm ftxin mm ftxin
NOTE: The dimensions do not include height of the shoe lug (except Item E).
T1-1-8
GENERAL / Component Layout
MAIN COMPONENTS
PHOTO
1 3
24
4 5 6
7
8
9
23
22 10
11
21
20 12
19 13
14
18 17 16 15 T1V1-01-02-013C
T1-2-1
GENERAL / Component Layout
3
4 5 6
2
7
11
T1V1-01-02-006C
10
1- Bucket 4 - Hose Rupture Valve (Arm 7- Hose Rupture Valve 10 - Hose Rupture Valve (Boom
Cylinder) (Positioning Cylinder) Cylinder)
2- Bucket Cylinder 5 - Arm Cylinder 8 - Positioning Cylinder 11 - Boom Cylinder
3- Arm 6 - Upper Boom 9 - Bottom Boom
T1-2-2
PHOTO
GENERAL / Component Layout
ELECTRICAL SYSTEM (OVERVIEW)
Engine
• Cam Angle Sensor
• Crank Speed Sensor
• Engine Oil Pressure Sensor
• Coolant Temperature Sensor
• Fuel Temperature Sensor
• Boost Temperature Sensor
Pump Device • Boost Pressure Sensor
1
• Pump 1,2 Delivery Pressure • Common Rail Pressure
Sensors Sensor
• Pumps 1, 2 Control Pressure • Overheat Switch
Sensors • Supply Pump Actuator
• Torque Control Solenoid Valve • EGR Valve
• Maximum Pump 2 Flow Rate • Injector
Limit Control Solenoid Valve • Glow Plug
Refer to T1-2-9. 13
Refer toT1-2-8.
12 Electrical System
Control Valve. (Relays)
• Pressure Sensor • Fresh Air Pressure
(Arm Roll-In) Sensor
• Pressure Sensor • Starter Relay 2
(Boom Raise) • Battery Relay
Refer to T1-2-10. • Glow Relay
• Fusible Link
Refer to T1-2-7.
11
10
1- Rear View Camera 5- GPS (Global Positioning 8 - Positioning Control Valve 11 - Hydraulic Oil Temperature
System) Aerial (2-Piece Boom Machine Sensor
Only)
2- Battery 6- Monitor Unit 9 - Working Light 12 - Solenoid Valve Unit
3- Communication Aerial 7- Horn 10 - Fuel Sensor 13 - Solenoid Pump
4- Air Filter Restriction
Switch
T1-2-3
GENERAL / Component Layout
Rear Tray
Refer to T1-2-5.
Switch Panel
Refer to T1-2-6.
T1V1-01-02-011C
1
T1-2-4
GENERAL / Component Layout
T1V1-01-02-007C
5 4
8 9 10 11
7
12
6
13
14
T1V1-01-02-009C
19 18 17 16 15
1- MC (Main Controller) 6- Starter Relay 2 (R5) 11 - Pilot Shut-Off Relay (R12) 16 - Light Relay 2 (R8)
2- Fuse Box 7- Starter Cut Relay (R4) 12 - Load Damp Relay (R1) 17 - ECM (Engine Control
Module) Main Relay (R14)
3- Dr. ZX Connector 8- OFF Relay (Air 13 - Wiper Relay (R6) 18 - Washer Relay (R9)
(Download Connector Conditioner) (R12)
Using Combinedly)
4 - ICF (Information 9- Security Horn Relay (R3) 14 - Light Relay 1 (R7) 19 - Horn Relay (R10)
Controller)
5 - Satellite Communication 10 - Air Conditioner Relay 15 - MAX HI Relay (Air
Terminal (Optional) (R11) Conditioner) (R13)
T1-2-5
GENERAL / Component Layout
PHOTO
Electrical System (Switch Panel)
2 5
1 6
T1V1-04-02-001C
1- Wiper / Washer Switch 3 - Engine Control Dial 5 - Power Mode Switch 6- Travel Mode Switch
2- Working Light Switch 4 - Auto-Idle Switch
T1-2-6
GENERAL / Component Layout
1 Air Cleaner
3 4 T1V1-01-02-012C
PHOTO
T1V1-01-02-018C
1- Atmospheric Pressure 3 - Fresh Air Pressure Sensor 5 - Battery Relay 7 - Fusible Link
Sensor
2 - Intake-Air Temperature 4 - Starter Relay 2 6 - Glow Relay
Sensor
T1-2-7
PHOTO
GENERAL / Component Layout
ENGINE
3 4 5
1
T1V1-01-02-017C
T1V1-01-02-016C
8 7
9 10 11 12 9
T1V1-01-02-015C
13
1- Cam Angle Sensor 5- Fuel Temperature Sensor 8- Hydraulic Oil Pressure 11 - Boost Temperature Sensor
Sensor
2- Overheat Switch 6- Crank Speed Sensor 9 - Injector 12 - Boost Pressure Sensor
3- Coolant temperature 7- Supply Pump Actuator 10 - EGR (Exhaust Gas 13 - Glow Plug
sensor Recirculation) Valve
4 - Common Rail Pressure
Sensor
T1-2-8
GENERAL / Component Layout
PUMP DEVICE
PHOTO PHOTO
1 2 3 8
7
6
5 4 T178-03-01-003C
T178-03-01-001C
SWING DEVICE
PHOTO ZX270-3 class
ZX200-3 class, ZX240-3 class
Front
10
11
T1V1-01-02-005C
11 T1V1-01-02-004C
1- Pilot Pump 4 - Pump 1 Delivery Pressure 7 - Maximum Pump 2 Flow 10 - Swing Relief Valve
Sensor Rate Limit Control Solenoid
Valve
2- Pump 2 5 - Pump 2 Delivery Pressure 8 - Pump 2 Control Pressure 11 - Pressure Sensor (Front
Sensor Sensor Attachment)
3- Pump 1 6 - Torque Control Solenoid 9 - Pump 1 Control Pressure
Valve Sensor
T1-2-9
GENERAL / Component Layout
CONTROL VALVE
PHOTO
1
T1V1-03-03-073C
PHOTO
3
T1V1-01-02-014C
1- Pressure Sensor (Arm 2- Pressure Sensor (Boom 3- Pressure Sensor (Swing) 4- Pressure Sensor (Travel)
Roll-In) Raise)
T1-2-10
GENERAL / Component Layout
SOLENOID VALVE UNIT
PHOTO
1 2 3 4
T1V1-03-07-007C
TRAVEL DEVICE
ZX200-3 class, ZX240-3 class ZX270-3 class
5
5 5
PHOTO
T1HD-01-02-001C
T178-01-02-014C
5 6
1 - Solenoid Valve Unit SC 3- Solenoid Valve Unit SI 5- Counterbalance Valve 6 - Travel Relief Valve
2 - Solenoid Valve Unit SF 4- Solenoid Valve Unit SG
T1-2-11
GENERAL / Component Layout
(Blank)
T1-2-12
GENERAL / Component Specifications
ENGINE
ZX200-3 class:
Manufacturer.................................................. ISUZU
Model ............................................................. 4HK1XYSA-02
Type ............................................................... Diesel, 4-Cycle, Water-cooled, Direct Injection Type, Exhaust
Turbo Charged Type
Cyl. No.- Bore × Stroke .................................. 4-115 mm×125 mm (4.5 in×4.92 in)
Piston Displacement ...................................... 5193 cm3 (317 in3)
Rated Output.................................................. 114 kW/1800 min-1 (155 PS/1800 rpm)
HP Mode: 122 kW / 2000 min-1 (166 PS / 2000 rpm)
Compression Ratio ........................................ 17.5
Dry Weight ..................................................... 478 kg (1055 lb)
Firing Order.................................................... 1-3-4-2
Rotation Direction .......................................... Clockwise (Viewed from fan side)
ZX240-3 class:
Manufacturer.................................................. ISUZU
Model ............................................................. 4HK1XYSA-01
Type ............................................................... Diesel, 4-Cycle, Water-cooled, Direct Injection Type, Exhaust
Turbo Charged Type
Cyl. No.- Bore × Stroke .................................. 4-115 mm×125 mm (4.5 in×4.92 in)
Piston Displacement ...................................... 5193 cm3 (317 in3)
Rated Output.................................................. 127 kW/1900 min-1 (173 PS/1900 rpm)
HP Mode: 132 kW / 2000 min-1 (180 PS / 2000 rpm)
Compression Ratio ........................................ 17.5
Dry Weight ..................................................... 478 kg (1055 lb)
Firing Order.................................................... 1-3-4-2
Rotation Direction .......................................... Clockwise (Viewed from fan side)
ZX270-3 class:
Manufacturer.................................................. ISUZU
Model ............................................................. 4HK1XYSA-03
Type ............................................................... Diesel, 4-Cycle, Water-cooled, Direct Injection Type, Exhaust
Turbo Charged Type
Cyl. No.- Bore × Stroke .................................. 4-115 mm×125 mm (4.5 in×4.92 in)
Piston Displacement ...................................... 5193 cm3 (317 in3)
Rated Output.................................................. 136 kW/2000 min-1 (185 PS/2000 rpm)
HP Mode: 140 kW / 2100 min-1 (190 PS / 2100 rpm)
Compression Ratio ........................................ 17.5
Dry Weight ..................................................... 478 kg (1055 lb)
Firing Order.................................................... 1-3-4-2
Rotation Direction .......................................... Clockwise (Viewed from fan side)
T1-3-1
GENERAL / Component Specifications
COOLING SYSTEM
Cooling Fan .............................................. Dia. 650 mm (25.6 in), 5 Blades, Draw-in Type, Synthetic Resin,
with Fan Ring and Safety Net
Fan Pulley Ratio........................................ Belt Driven Rotation Ratio: 0.95 (ZX200-3 class)
1.01 (ZX240-3 class, ZX270-3 class)
Thermostat ................................................ Cracking Temperature at Atmospheric Pressure: 82 °C (180 °F)
Full Open (Stroke: 10 mm or more) Temperature: 95 °C (203 °F)
Water Pump .............................................. Centrifugal Type
LUBRICATION SYSTEM
Lubrication Pump Type .................................. Gear Pump
Oil Filter.......................................................... Full-Flow Paper Element Type with Bypass
Oil Cooler ....................................................... Water Cooled Integral 4-Stage Type
STARTING SYSTEM
Motor ..............................................................Magnetic Pinion Shift Reduction Type
Voltage / Output .............................................24 V / 5 kW
PREHEAT SYSTEM
Preheating Method.........................................Glow Plug (24V, QOS ⅡType)
ALTERNATOR
Type ............................................................... Regulator Integrated AC Type, Brushless
Voltage / Output ............................................. 24 V / 50 A (Brushless)
SUPERCHARGING SYSTEM
Type ............................................................... Exhaust-Turbocharger Type RHF55 Type with Weight Gate
FUEL SYSTEM
Type ...............................................................Common Rail Type HP3 Type
Governor ........................................................Electronic All Speed Control
Injection Nozzle ............................................Electrical Multi-Hole Injector
T1-3-2
GENERAL / Component Specifications
PERFORMANCE
IMPORTANT: This list shows design specifications, which are not servicing standards.
ZX200-3 class:
Fuel Consumption Ratio ................................ 224 g/kW/h (304 g/PS⋅h) at 122 kW / (at Full Load:
2000 min-1)
219 g/kW/h (298 g/PS⋅h) at 114 kW / (at Working Load:
1800 min-1)
Maximum Output Torque................................ 655±60 N⋅m (67±6 kgf⋅m) at approx. 1500 min-1
Compression Pressure .................................. 3.04 MPa (31 kgf/cm2) at 200 min-1
Valve Clearance (Inlet / Exhaust) .................. 0.4 / 0.4 mm (when cool)
No Load Speed ............................................ Slow: (at Full Load: 800±20 min-1)
Fast: (at Full Load: 2000±20 min-1)
(at Working Load: 1800±20 min-1)
ZX240-3 class:
Fuel Consumption Ratio ................................ 221 g/kW/h (300 g/PS⋅h) at 132 kW / (at Full Load:
2000 min-1)
216 g/kW/h (293 g/PS⋅h) at 127 kW / (at Working Load: 1900
min-1)
Maximum Output Torque................................ 673 N⋅m (69 kgf⋅m) at approx. 1500 min-1
Compression Pressure .................................. 3.04 MPa (31 kgf/cm2) at 200 min-1
Valve Clearance (Inlet / Exhaust) .................. 0.4 / 0.4 mm (when cool)
No Load Speed ............................................ Slow: (at Full Load: 800±20 min-1)
Fast: (at Full Load: 2000±20 min-1)
(at Working Load: 1900±20 min-1)
ZX270-3 class:
Fuel Consumption Ratio ................................ 221 g/kW/h (300 g/PS⋅h) at 140 kW / (at Full Load:
2100 min-1)
216 g/kW/h (293 g/PS⋅h) at 136 kW / (at Working Load: 2000
min-1)
Maximum Output Torque................................ 676 N⋅m (65 kgf⋅m) at approx. 1500 min-1
Compression Pressure .................................. 3.04 MPa (31 kgf/cm2) at 200 min-1
Valve Clearance (Inlet / Exhaust) .................. 0.4 / 0.4 mm (when cool)
No Load Speed ............................................ Slow: (at Full Load: 800±20 min-1)
Fast: (at Full Load: 2100±20 min-1)
(at Working Load: 2000±20 min-1)
T1-3-3
GENERAL / Component Specifications
ZX200-3 class:
Engine Performance Curve (4HK1XYSA-02)
Test Condition: 1. In conformity with JIS D1005 (Performance Test Method for Diesel Engine Used for Construc-
tion Machinery) under standard atmospheric pressure.
2. Equipped with the fan and alternator.
600
500
400
Output 120
(kW)
100
80
60
40
20
0
260 Fuel Consumption
Ratio (g/PS⋅h)
240
220
200
-1
Engine Speed min (rpm) T1GR-01-02-002
T1-3-4
GENERAL / Component Specifications
ZX240-3 class:
Engine Performance Curve (4HK1XYSA-01)
Test Condition: 1. In conformity with JIS D1005 (Performance Test Method for Diesel Engine Used for Construc-
tion Machinery) under standard atmospheric pressure.
2. Equipped with the fan and alternator.
600
500
400
Output (kW) 160
140
120
100
80
60
40
20
Fuel Consumption
260 Ratio (g/PS⋅h)
240
220
0
500 1000 1500 2000 2500 T1V1-01-03-002
-1
Engine Speed min (rpm)
T1-3-5
GENERAL / Component Specifications
ZX270-3 class:
Engine Performance Curve (4HK1XYSA-03)
Test Condition: 1. In conformity with JIS D1005 (Performance Test Method for Diesel Engine Used for Construc-
tion Machinery) under standard atmospheric pressure.
2. Equipped with the fan and alternator.
600
500
400
120
100
80
60
40
20
220
200
800 1000 1200 1400 1600 1800 2000 2200 T1V1-01-03-003
-1
Engine Speed min (rpm)
T1-3-6
GENERAL / Component Specifications
ENGINE ACCESSORIES
RADIATOR ASSEMBLY
ZX200-3 class:
Type ...............................................................Parallel Type
Weight ............................................................59 kg (130 lb)
Intercooler
Capacity ......................................................... 8.0 L (2.1 US gal)
Air-Tight Test Pressure .................................. 245 kPa (2.5 kgf/cm2, 36 psi)
Cap Opening Pressure .................................. −
Intercooler
Capacity ......................................................... 8.5 L (2.2 US gal)
Air-Tight Test Pressure .................................. 245 kPa (2.5 kgf/cm2, 36 psi)
Cap Opening Pressure .................................. −
T1-3-7
GENERAL / Component Specifications
FUEL COOLER
Weight ............................................................ 0.7 kg (1.5 lb)
Core Type....................................................... Wavy Fin
Capacity ......................................................... 0.2 L (0.05 US gal.)
BATTERY
Capacity ......................................................... 88 Ah (5-Hour Rate)
Voltage ........................................................... 12 V
Weight ............................................................ 27.5 kg (61 lb)×2
Solenoid Pump
Manufacture Product No................................ B6952B-00-00
Rated Voltage ................................................ DC24V
T1-3-8
GENERAL / Component Specifications
HYDRAULIC COMPONENT
PUMP DEVICE
Drive Gear Ratio ............................................ Main Pump: 1, Pilot Pump: 1
MAIN PUMP
Type ............................................................... Bent-Axis Type Variable Displacement Axial Plunger Pump
Maximum Flow Rate ...................................... 212 L/min (56 US gpm)×2 (ZX200-3 class)
216 L/min (57 US gpm)×2 (ZX240-3 class)
227 L/min (59.9 US gpm)×2 (ZX270-3 class)
Maximum Flow Rate (Theoretical Value)....... 118 L/min (31.1 US gpm)×2
Rated Pressure .............................................. 34.3 MPa
REGULATOR
Type ............................................................... Hydraulic Pressure Operated Type
PILOT PUMP
Model ............................................................. FS 11/16.8
Type ............................................................... Fixed Displacement Type Gear Pump
Maximum Flow (Theoretical Value) ............... 31.9 L/min (8.4 US gpm)
ZX200-3 class
HP Mode: 35.3 L/min (9.3 US gpm)
33.6 L/min (8.88 US gpm)
HP Mode: 35.28 L/min (9.32 US gpm) ZX240-3 class
34.44 L/min (9.10 US gpm)
HP Mode: 36.12 L/min (9.54 US gpm) ZX270-3 class
CONTROL VALVE
Type ............................................................... Pilot Pressure Operated Type (4-Spools + 5-Spools)
Main Relief Set-Pressure............................... Normal: 34.3 MPa (350 kgf/cm2, 4980 psi) at
150 L/min (39.6 US gpm)
Power Digging: 36.3 MPa (370 kgf/cm2) at
150 L/min (39.6 US gpm)
Overload Relief Set-Pressure ........................ 37.2 MPa (380 kgf/cm2, 5410 psi) at 50 L/min (13.2 US gpm)
(Boom Lower, Arm Roll-In, Bucket Roll-In)
39.2 MPa (400 kgf/cm2, 5690 psi) at 50 L/min (13.2 US gpm)
(Boom Raise, Arm Roll-Out, Bucket Roll-Out)
T1-3-9
GENERAL / Component Specifications
SWING DEVICE
ZX200-3 class:
Type ............................................................... Two-Stage Reduction Planetary Gear
Reduction Gear Ratio .................................... 17.53
ZX240-3 class:
Type ............................................................... Two-Stage Reduction Planetary Gear
Reduction Gear Ratio .................................... 21.75
ZX270-3 class:
Type ............................................................... Two-Stage Reduction Planetary Gear
Reduction Gear Ratio .................................... 17.513
SWING MOTOR
ZX200-3 class:
Model ............................................................. M5X130CHB-10A-29B
Type ............................................................... Swash-Plate Type, Fixed Displacement Axial Plunger Motor
ZX240-3 class:
Model ............................................................. M5X130CHB-10A-45A
Type ............................................................... Swash-Plate Type, Fixed Displacement Axial Plunger Motor
ZX270-3 class:
Model ............................................................. M5X180-10A-65A
Type ............................................................... Swash-Plate Type, Fixed Displacement Axial Plunger Motor
T1-3-10
GENERAL / Component Specifications
VALVE UNIT
ZX200-3 class:
Type ............................................................... Non Counterbalance Valve Type
Relief Set-Pressure........................................ 32.4 MPa (330 kgf/cm2, 4710 psi) at 170 L/min
ZX240-3 class:
Type ............................................................... Non Counterbalance Valve Type
Relief Set-Pressure........................................ 32.4 MPa (330 kgf/cm2, 4710 psi) at 180 L/min
ZX270-3 class:
Type ............................................................... Non Counterbalance Valve Type
Relief Set-Pressure........................................ 32.4 MPa (330 kgf/cm2, 4710 psi) at 190 L/min
TRAVEL DEVICE
ZX200-3 class:
Type ............................................................... Three-Stage Reduction Planetary Gear
Reduction Gear Ratio .................................... 58.702
ZX240-3 class:
Type ............................................................... Three-Stage Reduction Planetary Gear
Reduction Gear Ratio .................................... 64.863
ZX270-3 class:
Type ............................................................... Three-Stage Reduction Planetary Gear
Reduction Gear Ratio .................................... 70.842
T1-3-11
GENERAL / Component Specifications
TRAVEL MOTOR
ZX200-3 class:
Type ....................................................... Swash-Plate Type Variable Displacement Axial Plunger Motor
Maximum Flow (Theoretical Value)
(Fast/Slow) ........................... 79/122.5 L/min (20.8/32.3 US gpm)
ZX240-3 class:
Type ....................................................... Swash-Plate Type Variable Displacement Axial Plunger Motor
Maximum Flow (Theoretical Value)
(Fast/Slow) ........................... 75.7/122.5 L/min (20/32.3 US gpm)
ZX270-3 class:
Type ....................................................... Swash-Plate Type Variable Displacement Axial Plunger Motor
Maximum Flow (Theoretical Value)
(Fast/Slow) ........................... 86.5/145.5 L/min (22.8/38.4 US gpm)
T1-3-12
GENERAL / Component Specifications
Bucket
Rod Diameter......................................... 80 mm (3.15”)
Cylinder Bore ......................................... 115 mm (4.53”)
Stroke ..................................................... 1060 mm (3’6”)
Fully Retracted Length........................... 1590 mm (5’3”)
Plating Thickness................................... 30 µm (1.18 µm)
ZAXIS240-3:
Boom Arm
Rod Diameter......................................... 90 mm (3.54”) 100 mm (3.94”)
Cylinder Bore ......................................... 125 mm (4.92”) 140 mm (5.51”)
Stroke ..................................................... 1390 mm (4’6”) 1610±3 mm (5’3±0.1”)
Fully Retracted Length........................... 1990 mm (6’6”) 2177 mm (7’1”)
Plating Thickness................................... 30 µm (1.18 µm) 30 µm (1.18 µm)
Bucket
Rod Diameter......................................... 90 mm (3.54”)
Cylinder Bore ......................................... 130 mm (5.12”)
Stroke ..................................................... 1075 mm (3’6”)
Fully Retracted Length........................... 1632 mm (5!4”)
Plating Thickness................................... 30 µm (1.18 µm)
ZAXIS270-3:
Boom Arm
Rod Diameter......................................... 95 mm (3.74”) 105 mm (4’1”)
Cylinder Bore ......................................... 135 mm (5.32”) 150 mm (5’9”)
Stroke ..................................................... 1360 mm (4’5”) 1659 mm (5’5”)
Fully Retracted Length........................... 1940 mm (6’4”) 2259 mm (7’4”)
Plating Thickness................................... 30 µm (1.18 µm) 30 µm (1.18 µm)
Bucket
Rod Diameter......................................... 90 mm (3.5”)
Cylinder Bore ......................................... 135 mm (5.32”)
Stroke ..................................................... 1070 mm (3’6”)
Fully Retracted Length........................... 1660 mm (5’5”)
Plating Thickness................................... 30 µm (1.18 µm)
T1-3-13
GENERAL / Component Specifications
CYLINDER (2-PIECE BOOM MACHINE)
ZAXIS240-3:
Boom Arm
Rod Diameter......................................... 90 mm (3.5”) 100 mm (3.94”)
Cylinder Bore ......................................... 125 mm (4.92”) 140 mm (5.51”)
Stroke ..................................................... 1390 mm (4’6”) 1610 mm (5’3”)
Fully Retracted Length........................... 1990 mm (6’6”) 2177 mm (7’1”)
Plating Thickness................................... 30 µm (1.18 µm) 30 µm (1.18 µm)
Bucket Positioning
Rod Diameter......................................... 90 mm (3.5”) 100 mm (3.94”)
Cylinder Bore ......................................... 130 mm (5.12”) 150 mm (5.91”)
Stroke ..................................................... 1075 mm (3’6”) 1327 mm (4’4”)
Fully Retracted Length........................... 1632 mm (5’4”) 1910 mm (6’3”)
Plating Thickness................................... 30 µm (1.18 µm) 30 µm (1.18 µm)
ZAXIS270-3:
Boom Arm
Rod Diameter......................................... 95 mm (3.7”) 105 mm (4.1”)
Cylinder Bore ......................................... 135 mm (5.3”) 150 mm (5.9”)
Stroke ..................................................... 1360 mm (4’6”) 1659 mm (5’5”)
Fully Retracted Length........................... 1940 mm (6’4”) 2259 mm (7’5”)
Plating Thickness................................... 30 µm (1.18 µm) 30 µm (1.18 µm)
Bucket Positioning
Rod Diameter......................................... 90 mm (3.5”) 100 mm (3.94”)
Cylinder Bore ......................................... 135 mm (5.32”) 150 mm (5.91”)
Stroke ..................................................... 1070 mm (3’6”) 1327 mm (4’4”)
Fully Retracted Length........................... 1660 mm (5’5”) 1910 mm (6’3”)
Plating Thickness................................... 30 µm (1.18 µm) 30 µm (1.18 µm)
T1-3-14
GENERAL / Component Specifications
FRONT ATTACHMENT PILOT VALVE
Model ............................................................. HVP06J-040-101
Plunger Stroke ............................................... Ports 1, 3: 6.5 mm (0.26 in), Ports 2, 4: 8.0 mm (0.32 in)
FILTER
Engine Oil Filter ............................................. ISUZU 8973243860
Fuel Filter ....................................................... ISUZU 8973759081
Filtration
Air Cleaner ............................................. -
Full-Flow Filter ....................................... β10≥2.0
Suction Filter .......................................... 177 μm (80 mesh)
Pilot Filter ............................................... 10≥1.4
T1-3-15
GENERAL / Component Specifications
ELECTRICAL COMPONENT
BATTERY RELAY
Voltage / Current ............................................24 V / 100 A
STARTER RELAY 2
Voltage ........................................................... 24 V
GLOW RELAY
Voltage ........................................................... 24 V
HORN
Voltage / Current ............................................ 24 V⋅2.5±0.5 A
Sound Pressure ............................................. 113±5 dB (A) @2 m
ILLUMINATION
Specifications ................................................. Working Light: Halogen 24V, 70 W / 60 W
Cab Light: 24 V, 10 W
AIR CONDITIONER
Refrigerant ................................................... 134 a
Cooling Ability ................................................ 19.3 MJ/h (4600 kcal/h)
Cool Air Volume ............................................. 550 m3/h or More
Heating Ability ................................................ 21.0 MJ/h (5000 kcal/h) or More
Warm Air Volume ........................................... 500 m3/h or More
Temperature Adjusting System ...................... Electronic Type
Refrigerant Quantity....................................... 850±50 g
Compressor Oil Quantity ............................... 210 cm3
T1-3-16
SECTION 2
SYSTEM
—CONTENTS—
Group 1 Controller Group 5 Electrical System
Outline .....................................................T2-1-1 Outline .....................................................T2-5-1
Can (Network Provided for Machine) ........T2-1-2 Main Circuit ..............................................T2-5-2
MC: Main Controller .................................T2-1-4 Electric Power Circuit (Key Switch: OFF) ..T2-5-4
ECM: Engine Control Module .................T2-1-20 Accessory Circuit......................................T2-5-6
ICF: Information Controller .....................T2-1-22 Starting Circuit (Key Switch: START) ........T2-5-8
Outline ...................................................T2-1-25 Charging Circuit (Key Switch: ON) ..........T2-5-12
Serge Voltage Prevention Circuit ............T2-5-16
Group 2 Control System Pilot Shut-Off Circuit (Key Switch: ON) ...T2-5-18
1V1T-2-1
(Blank)
1V1T-2-2
SYSTEM / Controller
OUTLINE
The controllers are provided for each control
respectively.
Each controller is connected by using CAN (network
provided for machine) in order to display on the
monitor unit in cab or the monitoring of machine
overall condition including the engine.
• MC:Main Controller
• ICF:Information Controller
• Monitor Unit
Dr.ZX
Satellite Terminal
(Optional)
MC
ECM
T2-1-1
SYSTEM / Controller
CAN (NETWORK PROVIDED FOR
MACHINE)
MC, ECM, ICF and the monitor unit are connected by
using CAN bus line and communicate the signal and
data each other.
Dr.ZX
Satellite Terminal
(Optional)
CAN High
MC
CAN Low
ECM
T1V1-02-01-050C
T2-1-2
SYSTEM / Controller
(Blank)
T2-1-3
SYSTEM / Controller
MC: MAIN CONTROLLER
Function Outline
Engine Control
• Engine Control Dial Control
MC sends the signal to ECM according to the idle • E Mode Control
position of engine control dial and controls the engine Condition:
speed. Pump Control Pressure and Pump Average
When all control levers are in neutral with the engine Delivery Pressure: Both Low Pressure
control dial at fast idle position, MC sends the signal Pump Control Pressure and Pump Average
to ECM and reduces engine speed by 100 min –1 Delivery Pressure: Both High Pressure
from the fast idle speed. Pump Control Pressure: Low Pressure and Pump
Average Delivery Pressure: High Pressure
• HP Mode Control Engine Control Dial: Engine Speed 1800 min-1 or
Average Delivery Pressure of Pumps 1 and 2: High faster
Engine Control Dial: Engine Speed 1500 min-1 or Power Mode Switch: E Mode Position
faster On conditions above, MC sends the signal to ECM and
Power Mode Switch: HP Mode Position decreases engine speed below the set speed of
When operating boom raise and arm roll-in on engine control dial.
conditions above, MC sends the signal to ECM and Pump Control Pressure: High Pressure and Pump
increases engine speed beyond the set speed of Average Delivery Pressure: Low Pressure
engine control dial in order to increase engine power. On conditions above, MC sends the signal to ECM and
increases engine speed 200 min-1 beyond the set
• Travel HP Mode Control speed of engine control dial.
ZX200-3 class, ZX240-3 class
Average Delivery Pressure of Pumps 1 and 2: High
Engine Control Dial: Fast Idle Position
Travel Mode Switch: Fast
When operating travel on conditions above, MC sends
the signal to ECM and increases engine speed beyond
the set speed of engine control dial in order to increase
travel speed.
When operating the front attachment at the same time,
this control becomes ineffective.
ZX270-3 class
Engine Control Dial: Fast Idle Position
When operating travel on condition above, MC sends
the signal to ECM and increases engine speed beyond
the set speed of engine control dial in order to increase
travel speed.
When operating the front attachment at the same time,
this control becomes ineffective.
T2-1-4
SYSTEM / Controller
MC
Power Mode
Switch
(Fast)
ECM
Pump 2 Delivery Pump 1 Delivery
Pressure Sensor Pressure Sensor
Pressure Sensor
Travel
Front Attachment
Boom Raise
Pump 2 Control
Pressure Sensor
Arm Roll-In
Pump 1 Control
Pressure Sensor
T1V1-02-01-039C
T2-1-5
SYSTEM / Controller
• Auto-Idle Control • Attachment Operation Speed Limit Control
All Control Levers: Neutral Position (Optional)
Auto-Idle Switch: ON Set attachment operation speed to decrease (-) with Dr.
On conditions above, MC sends the signal to ECM and ZX in the service mode. When operating attachment,
set engine speed to auto-idle speed. MC sends the signal to ECM and decreases engine
When operating the engine control dial, shifting the speed to the attachment operating speed set by Dr.
power mode switch (E mode to P mode or P mode to E ZX below fast idle.
mode) or operating travel, auto-idle control is released.
• Auto-Warming Up Control
When the hydraulic oil temperature is below 0 °C (32
°F) for 15 minutes after starting the engine, MC sends
the signal to ECM in response to the signal from key
switch and hydraulic oil temperature sensor, and
increases engine speed to auto warm-up speed.
• Heater Control
Coolant Temperature: Less than 5 °C (41 °F)
Pump Control Pressure of Pumps 1 and 2: 0.5 Mpa
(5.1 kgf/cm2, 37 psi) or less
Engine Control Dial: Fast Idle Position
When the engine starts on conditions above, MC send
the signal to ECM and increases engine speed beyond
fast idle speed.
T2-1-6
SYSTEM / Controller
Key Switch
MC
Monitor Unit: ML ON
Oil Temperature
Sensor
Auto-Idle Switch
E Mode To ICF
Coolant
Temperature Sensor
ECM
Pressure Sensor
Travel
Front Attachment
Auxiliary (Optional)
Coolant
Temperature Pump 2 Control
Signal Pressure Sensor
Pump 1 Control
Pressure Sensor
T1V5-02-01-001C
T2-1-7
SYSTEM / Controller
Pump Control
• Speed Sensing Control • Pump 3 Flow Rate Limit Control (Optional)
MC calculates difference between engine speed set by As for the machine equipped with pump 3, MC drives
the engine control dial and actual engine speed the torque control solenoid valve according to the
detected by ECM. MC sends the signal to the torque signal from pump 3 delivery pressure sensor,
control solenoid valve in order to control pilot pressure decreases delivery flow rate of pumps 1, 2, and
to the pump regulator. The pump delivery flow rate is controls pump 1, 2, 3 absorption power (pump torque)
changed due to engine speed so that engine power in order not to exceed engine power.
can be used effectively.
T2-1-8
SYSTEM / Controller
MC
CAN Bus Line
Engine Control Dial
ICF, Monitor Unit
Travel
Pump 1 Delivery
Pressure Sensor
ECM Pump 2 Delivery Pump 3 Delivery
Pressure Sensor Pressure Sensor
Actual Engine
Speed
Torque Control
Solenoid Valve
Maximum Pump 2
Flow Rate Limit Control
Solenoid Valve
Maximum Pump 1
Flow Rate Limit Control
Solenoid Valve
T1V1-02-01-041C
T2-1-9
SYSTEM / Controller
Valve Control
• Power Digging Control
While the power digging switch is turned ON, MC
drives solenoid valve unit (SG) and increases relief
pressure of the main relief valve in control valve.
T2-1-10
SYSTEM / Controller
MC
To ICF, Monitor Unit
Boom Raise
To Arm Regenerative
Arm Roll-In
Valve (Control Valve)
T1V1-02-01-042C
T2-1-11
SYSTEM / Controller
• Travel Motor Displacement Angle Selection
Control
ZX200-3 class, ZX240-3 class
Condition:
Pump 1, 2 Delivery Pressure: Either Low
Pump 1, 2 Control Pressure: Either High
Travel Mode Switch: Fast
When operating travel on conditions above, MC drives
solenoid valve unit (SI) according to the signals from
pressure sensor (travel), pump 1, 2 delivery pressure
sensors and pump 1, 2 control pressure sensors.
When pilot pressure from solenoid valve unit (SI) acts
on the travel motor displacement angle selection valve,
reduces displacement angle of the travel motor, and
increases travel speed.
ZX270-3 class
Condition:
Pump 1,2 Delivery Pressure: Low
Pump 1, 2 Control Pressure: High
Travel Mode Switch: Fast
When operating travel on conditions above, MC drives
solenoid valve unit (SI) according to the signals from
pressure sensor (travel), pump 1, 2 delivery pressure
sensors and pump 1, 2 control pressure sensors.
When pilot pressure from solenoid valve unit (SI) acts
on the travel motor displacement angle selection valve,
reduces displacement angle of the travel motor, and
increases travel speed.
T2-1-12
SYSTEM / Controller
Monitor Unit
Pressure Sensor
Travel
To ICF
Beacon Light
CAN Bus Line
Displacement Angle
Pump 2 Delivery Selection Valve
Pressure Sensor
Pump 1 Delivery
Pressure Sensor
Pump 2 Control
Pressure Sensor
Pump 1 Control
Pressure Sensor
T1V5-02-01-002C
T2-1-13
SYSTEM / Controller
• HSB Breaker Control (Optional)
As for the machine equipped with HSB breaker, when
breaker 1 is selected on the monitor unit or is set by Dr.
ZX, MC drives the selector valve control solenoid valve
and the secondary pilot relief pressure control solenoid
valve.
Pilot pressure from the selector valve control solenoid
valve shifts the selector valve and connects the return
circuit in breaker to hydraulic oil tank.
Pilot pressure from the secondary pilot relief pressure
control solenoid valve shifts the secondary pilot relief
pressure control valve and reduces relief set pressure
in the breaker circuit.
T2-1-14
SYSTEM / Controller
Breaker Accumulator
Control Valve
Monitor Unit
Accumulator
MC
Selector Valve
• Attachment Selection Signal
Secondary Pilot
• Pump 2 Flow Rate Relief Pressure
Fine Adjustment Signal Valve
Accumulator Control
Solenoid Valve
Maximum Pump 2
T1V5-02-01-003C
Flow Rate Limit
Solenoid Valve
T2-1-15
SYSTEM / Controller
• Secondary Crusher Control (Optional)
As for the machine equipped with the secondary
crusher, when secondary crusher 1 is selected on the
monitor unit or is set by Dr. ZX, MC drives the auxiliary
flow combining solenoid valve.
When operating the secondary crusher, pilot pressure
from the attachment pilot valve shifts the bypass
shut-out valve and the auxiliary flow combining valve
through the auxiliary flow combining solenoid valve.
When pressure oil from pump 1 is combined with
pressure oil from pump 2 through the auxiliary flow
combining valve. Therefore, combined pressure oil
flows to the auxiliary spool and speed operating the
secondary crusher increases.
When operating combined operation of arm roll-out,
arm roll-out + boom raise, swing or travel and
secondary crusher, MC drives the auxiliary flow rate
control solenoid valve according to the signals from
pressure sensors (auxiliary, arm roll-out, boom raise,
swing or travel) so that pressure oil to the secondary
crusher is restricted.
T2-1-16
SYSTEM / Controller
MC
Selector Valve
From Pump 1
Auxiliary Flow
• Attachment Selection Signal Combiner Valve
• Auxiliary Flow Rate Control Control Valve
Solenoid Valve Fine
Adjustment Signal
• Attachment Selection
Signal
ICF
CAN
Dr.ZX Bus
Line
Auxiliary Flow
Pressure Sensor Rate Control From Pilot
Solenoid Valve Pump
Travel
Swing
Boom Raise
Auxiliary Flow
Arm Roll-Out Rate Control Valve
Auxiliary
Bypass
Shut-Out Valve
From
Attachment
Pilot Valve
From
Auxiliary Flow Pump 2
Combining
Solenoid Valve
T1V5-02-01-004C
T2-1-17
SYSTEM / Controller
Other Controls
• Rear Monitoring Display Selection Control
MC shifts the monitor unit into the back-screen display
according to the signal from pressure sensor (travel) or
rear monitoring switch (optional).
T2-1-18
SYSTEM / Controller
Monitor Unit
MC
Rear Monitoring
Switch (Optional)
To ICF
Back-Screen
Buzzer
(Optional)
Swing Alarm
Relay (Optional)
Buzzer
(Optional)
Beacon Light
(Optional)
T1V1-02-01-046C
T2-1-19
SYSTEM / Controller
ECM: ENGINE CONTROL MODULE
Function Outline
• Fuel Injection Control
ECM detects the engine operating condition according
to the signals from each sensor and MC and controls
the fuel injection.
• EGR Control
ECM decides EGR gas amount according to engine
speed, fuel flow rate, coolant temperature,
atmospheric pressure and intake-air temperature.
ECM opens EGR valve and re-circulates exhaust gas,
amount of which is equal to EGR gas amount, in the
intake manifold. EGR gas is combined with intake-air
so that combustion temperature is lowered and NOx is
reduced.
T2-1-20
SYSTEM / Controller
ECM
Crank Speed Sensor
Common Rail
Glow Plug Relay Pressure Sensor
Common Rail
Supply Pump
Glow Plug
Fuel Tank
Injector
T1V1-02-01-047C
T2-1-21
SYSTEM / Controller
ICF: INFORMATION CONTROLLER
Function Outline
• Operating Hours Management
The built-in clock is provided for ICF.
ICF sends data of built-in clock to the monitor unit by
using CAN bus line.
• Maintenance History
When the maintenance key is pushed on the monitor
unit, time is recorded.
T2-1-22
SYSTEM / Controller
• Built-In Clock
ECM
Satellite Terminal
(Optional)
• GPS
Monitor Unit
Center Server
Dr.ZX
T1V1-02-01-049C
T2-1-23
SYSTEM / Controller
(Blank)
T2-1-24
SYSTEM / Controller
OUTLINE
Function Outline
Primary Screen
1 2 3 4 5 6 7 8
22 10
11
12
13
14
15
21 20 19 18 17 16
T1V1-05-01-094C
1 - Work Mode Display 7 - Work Mode Display 13 - Fuel Consumption Gauge 18 - Mail Selection (Optional)
2 - Auto-Idle Display 8 - Hour Meter 14 - Clock 19 - ML Crane Selection
(Optional)
3 - ML Crane Display or 9 - ML Crane Display 15 - Back-Screen Selection 20 - Work Mode Selection
Overload Alarm Display (Optional)
(Optional)
4 - Auxiliary 10 - Fuel Gauge 16 - Menu 21 - Return to Primary Screen
5 - Auxiliary 11 - Mail Display (Optional) 17 - Auxiliary Selection 22 - Coolant Temperature
Gauge
6 - Glow Display 12 - Auxiliary
T2-1-25
SYSTEM / Controller
• Display of Meters
Work Mode 2
Data to be displayed on each meter are received
from other controllers (MC, ICF and ECM) by using
CAN, and are displayed on the monitor unit.
1 3
Items to be displayed
1. Coolant Temperature Gauge
2. Hour Meter
3. Fuel Gauge
4. Clock
4
Digging Mode
T1V1-05-01-108
Attachment Mode
Breaker
T1V1-05-01-104
Pulverizer
T1V1-05-01-105
Crusher
T1V1-05-01-106
Vibrating Hammer
T1V1-05-01-107
Others
T1V1-05-02-003
T2-1-26
SYSTEM / Controller
• Auto-Idle Display(1)
When selecting auto-idle from the switch panel, the 1 2 3
data according to the signals received from MC by
using CAN is displayed.
When the key is turned ON, the data blinks for 10
seconds.
T1V1-05-02-001
2
T1V1-05-02-002C
T2-1-27
SYSTEM / Controller
• Fuel Sensor Error Display Coolant Temperature Fuel Sensor Error
When the fuel sensor is faulty or if the harness Sensor Error Display Display
between fuel sensor and monitor unit is broken, the
data is displayed on the fuel gauge.
T2-1-28
SYSTEM / Controller
• Troubleshooting
This screen displays fault codes according to the
signals received from ICF by using CAN.
• Controller Version
This screen displays the version of controller.
T1V5-05-01-087C
Monitoring Screen
• Operating Conditions
This screen displays machine hour, fuel usage and
fuel consumption rate registered by the monitor unit.
T2-1-29
SYSTEM / Controller
• Pump 2 Flow Rate Adjustment
(Only machines equipped with optional parts)
When using the attachments, fine adjust flow rate of
pump 2 by keys 1 and 2 operation.
The signals from the monitoring unit are sent to MC
by using CAN.
When breaker 1 or 2 is used, MC adjusts flow rate of
pump 2 while controlling maximum pump 2 flow rate
limit control solenoid valve. When using pulverizer 1
or crusher 1, MC adjusts flow rate of pressure oil that
flows from Pump 2 to pulverizer or crusher while Key 1
controlling the auxiliary flow rate control solenoid
valve. (Refer to "Control Systems.") Key 2
Type of 2-Speed Valve Selector Accumulator Secondary Pump 2 Flow Auxiliary Flow
Attachments Selector Circuit Circuit Circuit Pilot Rate Control Rate Control
Relief Pressure
Circuit
Breaker 1 OFF to Hydraulic OFF ON ON OFF
Oil Tank
Breaker 2 OFF to Hydraulic ON OFF ON OFF
Oil Tank
Pulverizer 1 ON to Control Valve OFF OFF OFF ON
Crusher 1 ON to Control Valve OFF OFF OFF ON
T2-1-30
SYSTEM / Controller
• Attachment Selection
(Only machines equipped with optional parts)
On this screen, select digging mode and attachment
mode set by Dr. ZX.
T2-1-31
SYSTEM / Controller
• Back Monitor Settings
By key operation, image display ON and OFF of
Auto-Control for switching image of the back monitor
while traveling pilot time and display format on the
screen of the rear view camera can be set.
T1V1-05-01-126C
T1V1-05-01-127C
Mirror Image Screen
T2-1-32
SYSTEM / Controller
• Maintenance Settings
This screen displays the hour meter reading at
replacement time and the remaining hours until the
next replacement.
As the items to be replaced are displayed in a list,
record performed replacement by selecting an item
from the list.
• Mail
(Optional Function)
Send requests such as general, fuel replenishment,
service maintenance, and forwarding requests in the
mail switch screen.
Contents of mails are registered in ICF, and are sent
to the central server by a satellite terminal.
T2-1-33
SYSTEM / Controller
• Overload Alarm
Alarm
(Only machines equipped with optional parts)
T2-1-34
SYSTEM / Control System
OUTLINE
MC (Main Controller) is used to control the machine MC sends the signals equivalent to the target engine
operations. The signals from engine control dial, speed to ECM (Engine Control Module) by using CAM
various sensors and switches are sent to MC and communication in order to control the engine. (Refer to
processed in the logic circuit. ECM System/ SYSTEM.) MC drives the solenoid valve
unit and torque control solenoid valve in order to
control the pump and valve.
Continued to T2-2-2
T2-2-1
SYSTEM / Control System
CAN Communication
• Actual Engine Speed (From ECM) →
• Work Mode (Digging / Attachment)
(From Monitor Unit) →
T2-2-2
SYSTEM / Control System
(Blank)
T2-2-3
SYSTEM / Control System
ENGINE CONTROL
The engine control consists of the following functions.
T2-2-4
SYSTEM / Control System
Engine Control System Layout
Oil
Temperature
Sensor
Pressure Sensor
Travel
Front Attachment
Swing
Key Switch
Boom Raise
Arm Roll-In
Auxiliary (Optional)
Engine Arm Roll-Out (Optional)
Control Dial CAN Communication Crane Mode
Monitor Unit (Optional)
Auto-Idle MC
Switch ML
Digging Attachment
Mode Mode 1 to 5
Power Mode Switch
ICF
HP Mode
E Mode
P Mode
Pump 2 Delivery Pump 1 Delivery
Pressure Sensor Pressure Sensor
ECM
T1V1-02-01-002C
T2-2-5
SYSTEM / Control System
Engine Control Dial Control
Engine speed is
Purpose: Controls the engine speed according to the reduced by 100
rotation angle of engine control dial. Engine -1
min when the
Speed
Reduces the engine speed by 100 min-1 in control levers are in
neutral.
order to reduce fuel consumption and noise
level when all the control levers are in
neutral.
Operation:
1. MC sends the signals equivalent to target engine
speed to ECM by using CAN communication
according to rotation angle of the engine control
Engine
dial. Control Dial
2. ECM controls the engine speed according to CAN Slow Idle Fast Idle Position
communication.
3. When the engine control dial is in the fast idle
speed position and all the control levers are
turned to the neutral position (pressure sensors
(travel, front attachment): OFF), MC sends the
signal to ECM by using CAN communication after
one second.
4. ECM reduces the engine speed by 100 min-1 from
fast idle speed (P mode engine speed).
T2-2-6
SYSTEM / Control System
Pressure Sensor
Travel
Front Attachment
Engine
Control Dial CAN Communication
MC
Dr. ZX
ICF
ECM
T1V1-02-01-005C
T2-2-7
SYSTEM / Control System
HP Mode Control
Condition: Engine
• Engine Control Dial: Set at 1500 min-1 or faster. Control Dial
Position
• Boom Raise or Arm Roll-In Operation: Operated Slow Idle Fast Idle
• Average Delivery Pressure of Pumps 1 and 2:
High
(Reference: ZAXIS200-3, ZAXIS240-3: 25 MPa,
(255 kgf/cm2, 3635 psi)
ZAXIS270-3: 20 MPa, (205 kgf/cm2,
2910 psi)) Increasing Range of Fast
Model
Idle Speed
NOTE: HP control can be made operable or ZAXIS200-3 200 min−1
inoperable by Dr. ZX. Although the key ZAXIS240-3 100 min−1
switch is turned OFF, the setting is kept. ZAXIS270-3 100 min−1
T2-2-8
SYSTEM / Control System
Pressure Sensor
Boom Raise
Arm Roll-In
Engine
Control Dial CAN Communication
MC
Dr. ZX
Power Mode Switch ICF
HP Mode
T1V1-02-01-006C
T2-2-9
SYSTEM / Control System
Travel HP Mode Control
T2-2-10
SYSTEM / Control System
Pressure Sensor
Travel
Engine
Control Dial CAN Communication
MC
T1V1-02-01-014C
T2-2-11
SYSTEM / Control System
ZAXIS270-3
Operation:
1. When all the conditions exist, MC sends the
signals equivalent to the target engine speed Engine
according to the travel control to ECM by using Speed
1800 min
-1
Engine Speed
CAN communication. increases from
2. ECM increases the engine speed by 100 min-1 the fast idle
from the speed set by the engine control dial and 1750 min
-1 speed by 100
-1
min .
travels faster.
Condition:
• Engine Control Dial: Set the engine speed in the
fast idle speed position.
• Travel Operation: Operated Engine
• Front Attachment Operation: Not Operated Control Dial
• Delivery Pressure of Pumps 1 and 2: Delivery Slow Idle Fast Idle Position
pressure of either pump is high.
(Reference: 15 Mpa (153 kgf/cm2, 2180 psi))
T2-2-12
SYSTEM / Control System
Pressure Sensor
Travel
Engine
Control Dial CAN Communication
MC
ECM
T1V1-02-01-015C
T2-2-13
SYSTEM / Control System
E Mode Control
T2-2-14
SYSTEM / Control System
Engine
Control Dial CAN Communication
E Mode
T1V1-02-01-007C
T2-2-15
SYSTEM / Control System
Auto-Idle Control
Operation:
1. Approx. 3.5 seconds after the control lever is
turned to neutral with the auto-idle switch ON, MC Engine speed is
sends the signals equivalent to the auto-idle reduced to the
Engine auto-idle speed
speed to ECM by using CAN communication. Speed after 3.5 seconds.
2. ECM changes the engine speed into the auto-idle
speed. Fast Idle
3. As soon as either control lever is moved
(pressure sensors (travel, front attachment): ON),
MC returns the signals sending to ECM into those Auto-Idle
equivalent to the target engine speed set by the Speed
engine control dial.
4. ECM returns the engine speed into the original 1200 min
-1
engine speed.
Engine
Control Dial
Auto-Idle Deactivation Requirements: Slow Idle Fast Idle Position
• Control Lever: Operated (pressure sensor (travel
or front attachment): ON)
• Power Mode Switch: When the E mode is
changed to P mode or P mode is changed to E
mode
• Engine Control Dial: When the engine speed is
changed
T2-2-16
SYSTEM / Control System
Pressure Sensor
Travel
Front Attachment
Engine
Control Dial CAN Communication
Auto-Idle MC
Switch
Dr. ZX
Power Mode Switch
E Mode
ECM
T1V1-02-01-008C
T2-2-17
SYSTEM / Control System
Auto-Warming Up Control
T2-2-18
SYSTEM / Control System
Hydraulic Oil
Temperature
Sensor
Key Switch
Engine
Control Dial
CAN Communication
MC
Dr.ZX
ICF
ECM
T1V1-02-01-009C
T2-2-19
SYSTEM / Control System
Idle Speed-Up Control
Operation:
1. When the travel or front attachment functions is 900 min
-1
T2-2-20
SYSTEM / Control System
Pressure Sensor
Travel
Front Attachment
Engine
Control Dial CAN Communication
MC
ECM
T1V1-02-01-010C
T2-2-21
SYSTEM / Control System
Heater Control
Condition:
Engine
• Engine Control Dial: Set the engine speed at fast Control Dial
idle speed position. Slow Idle Fast Idle Position
• Front Attachment Operation: Not Operated
• Travel Operation: Not Operated
• Coolant Temperature: Less than 5 °C (41 °F).
• Pumps 1, 2 Control Pressure Sensors: Both pump
control pressures: 0.5 MPa (5.1 kgf/cm2, 73 psi) Increasing Range of Fast
or less. Model
Idle Speed
ZAXIS200-3 100 min−1
ZAXIS240-3 100 min−1
ZAXIS270-3 (HP mode engine speed)
T2-2-22
SYSTEM / Control System
Pressure Sensor
Travel
Front Attachment
Key Switch
Engine
Control Dial
MC
CAN Communication
Coolant
ECM Temperature
Sensor
T1V1-02-01-035C
T2-2-23
SYSTEM / Control System
Attachment Operation Speed Increase Control
(Only Machine Equipped with Front Attachment
Parts)
Operation:
1. When the following conditions exist and the front
attachment is operated, the MC sends the signals
equivalent to the target engine speed set by Dr. Engine
ZX to ECM by using CAN communication. Control Dial
2. ECM increases engine speed to the attachment Slow Fast Position
Idle Idle
operating speed set by Dr. ZX.
Conditions:
• Dr. ZX: Resets the maximum engine speed to a
faster (+) attachment (hydraulic breaker, NOTE: When the P mode engine speed is preset to
secondary crusher, hydraulic crusher or vibrating a slower speed in Dr. ZX service mode, the
hammer) operating speed in the service mode. maximum engine speed will not be
• Engine Control Dial: Fast Idle Speed Position increased when operating the attachment.
• Power Mode Switch: HP Mode
• Auxiliary: Operated
• Work Mode Switch: Attachment selected by using
the attachment mode monitor is reset by Dr. ZX.
T2-2-24
SYSTEM / Control System
Pressure Sensor
Auxiliary (Optional)
Engine
Control Dial CAN Communication
Monitor Unit
MC
Attachment Mode
1 to 5
Dr.ZX
Power Mode Switch ICF
HP Mode
ECM
T1V1-02-01-011C
T2-2-25
SYSTEM / Control System
Attachment Operation Speed Limit Control (Only
Machine Equipped with Front Attachment Parts)
Conditions:
• Dr. ZX: Resets the maximum engine speed to a
slower (−) attachment (hydraulic breaker,
secondary crusher, hydraulic crusher or vibrating
hammer) operating speed in the service mode.
• Work Mode: Attachment Mode
• Auxiliary Mode Switch (Optional): Attachment
position Attachment selected by using the
attachment mode monitor is reset by Dr. ZX
T2-2-26
SYSTEM / Control System
CAN Communication
Monitor Unit
MC
Attachment Mode
1 to 5
Dr.ZX
ICF
ECM
T1V1-02-01-012C
T2-2-27
SYSTEM / Control System
PUMP CONTROL
T2-2-28
SYSTEM / Control System
Pump Control System Layout
Pressure Sensor
Travel
Front Attachment
Auxiliary (Optional)
Engine
Control Dial
Monitor Unit
ICF
Pump 1 Delivery
Pressure Sensor
Pump 3 Delivery
Pump 2 Delivery Pressure Sensor
ECM Pressure Sensor (Optional)
T1V1-02-01-003C
T2-2-29
SYSTEM / Control System
Speed Sensing Control
Operation: Q
1. The target engine operating speed is set by Flow Rate
controlling the engine control dial.
2. MC calculates the difference in speed between Pump P-Q Curve
the target engine speed and the actual engine
speed monitored by CAN communication from
ECM. Then, MC sends signals to the torque
control solenoid valve.
3. The torque control solenoid valve delivers pilot
pressure oil in response to the received signals to
the pump regulator and controls the pump
delivery flow rate.
4. If the engine load increases and the actual engine
speed becomes slower than the target engine
speed, the pump swash angle is reduced so that
Pressure P
pump flow rate will be reduced. Therefore, the
engine load is reduced and engine stall is
prevented.
5. If the actual engine speed becomes faster than
the target engine speed, the pump swash angle is
increased so that pump flow rate will increase.
Therefore, the engine output can be utilized more
efficiently.
T2-2-30
SYSTEM / Control System
Engine
Control Dial
CAN Communication
MC
T1V1-02-01-016C
T2-2-31
SYSTEM / Control System
Travel Torque-Up Control
Q
Purpose: Effectively controls during single travel Flow Rate B
operation. Allows the machine to travel at the
maximum pump flow rate when the engine is Increased Torque
P-Q Curve
running at slow speed. When travel A
operation is made with the engine running at
slow speed, normally, the hydraulic pump
delivers pressure oil at the flow rate
corresponding to point A on the P-Q curve
illustrated to the right. Therefore, if any
difference exists between pump 1 and pump
Normal P-Q Curve
2 flow rate, the machine will mistrack. In
order to prevent mistracking, the pump P-Q
curve is raised so that, when traveling the
machine with the engine running at slow
Pressure P
speed, the pump delivers pressure oil at the
flow rate corresponding to point B (maximum
flow rate).
When travel operation is made with the
engine running at fast speed, the pump P-Q
curve is raised in order to improve travel
function.
Operation:
1. When the engine speed set by the engine control
dial is slow, MC processes signals from the travel
pressure sensor, and pump 1 and 2 delivery
pressure sensors, and sends the signals to torque
control solenoid valve.
2. The torque control solenoid valve delivers pilot
pressure corresponding to the received signals to
the regulator and increases pump flow rate.
T2-2-32
SYSTEM / Control System
Pressure Sensor
Travel
Front Attachment
Engine
Control Dial
MC
T1V1-02-01-018C
T2-2-33
SYSTEM / Control System
Attachment Pump Torque Decrease Control (Only
Machine Equipped with Front Attachment)
Operation:
1. When the following conditions exist and average
pump delivery pressure becomes high, the pumps
1, 2 delivery pressure sensors output the signal to
MC.
2. MC drives the torque control solenoid valve and
reduces delivery flow rate of pumps 1, 2.
3. Therefore, driving torque (pump torque) of pumps
1, 2 is controlled not to exceed the engine output
and hydraulic temperature is prevented from
rising while operating the front attachment.
Condition:
• Work Mode: Select secondary crushers 1 to 5 or
hydraulic crushers 1 to 5 at attachment mode.
• Attachment pump torque control is effective by Dr.
ZX.
T2-2-34
SYSTEM / Control System
Engine
Control Dial
CAN Communication Attachment Mode
Select secondary crusher or hydraulic
crusher.
Monitor Unit
MC
Dr.ZX
ICF
T1V1-02-01-017C
T2-2-35
SYSTEM / Control System
Pump 1 Flow Rate Limit Control (Only Machine
Equipped with Front Attachment)
Operation:
1. When a front attachment is used with the travel
control lever in neutral, MC receives the signals
from pressure sensor (auxiliary) (optional).
2. In response to front attachment control operation,
MC drives the maximum pump 1 flow rate limit
control solenoid valve (optional) and controls
pump 1 flow rate.
T2-2-36
SYSTEM / Control System
Pressure Sensor
Travel
Auxiliary (Optional)
MC
Dr.ZX
ICF
T1V1-02-01-019C
T2-2-37
SYSTEM / Control System
Pump 2 Flow Rate Limit Control (Only Machine
Equipped with Front Attachment)
Operation:
1. When a front attachment is used, MC receives the
signals from pressure sensor (auxiliary) Normal Pump P-Q Curve
(optional).
2. In response to front attachment control operation,
MC drives the maximum pump 2 flow rate limit
control solenoid valve and reduces maximum
pump flow rate.
3. When the auxiliary flow combining solenoid valve
stops, pump 2 flow rate can be adjusted finely by
the monitor unit.
Pressure P
NOTE: In proportion to the attachment control
operation, maximum pump flow rated is
reduced. The minimum pump swash
set-angle on monitor unit for a front
attachment (hydraulic breaker 1 to 5,
secondary crusher 1 to 5, hydraulic crusher
1 to 5 or vibrating hammer 1 to 5) can be
set in the service mode of Dr. ZX.
T2-2-38
SYSTEM / Control System
Pressure Sensor
Travel
Auxiliary (Optional)
Monitor Unit
MC
Dr.ZX
ICF
Solenoid Valve
T2-2-39
SYSTEM / Control System
Pump 3 Torque Decrease Control (Only Machine
Q
Equipped with Optional Parts)
T2-2-40
SYSTEM / Control System
MC
Pump 3 Delivery
Pressure Sensor
T1V1-02-01-021C
T2-2-41
SYSTEM / Control System
VALVE CONTROL
The valve control system functions as follows:
T2-2-42
SYSTEM / Control System
Dr.ZX
Power Digging Oil
Switch
ICF
Fast
Digging
Pump 1 Control Pressure Sensor Regenerative Spool
Solenoid Valve Unit Main Relief Valve
SG
SI
SF
SC
Auxiliary Flow
Control Solenoid
Valve (Optional.)
Auxiliary Flow
Rate Control Valve
Travel Motor
Swash Angle
Selection Valve
T1V1-02-01-004C
T2-2-43
SYSTEM / Control System
Power Digging Control
Operation:
1. For maximum 8 seconds after the power digging
switch is turned ON, MC continuously activates
solenoid valve unit (SG).
2. Solenoid valve unit (SG) delivers pilot pressure to
the main relief valve in control valve and
increases relief pressure. (Refer to Control Valve /
COMPONENT OPERATION.)
T2-2-44
SYSTEM / Control System
Power Digging
Switch
MC ICF
T1V1-02-01-024C
T2-2-45
SYSTEM / Control System
Auto-Power Lift Control
Operation:
1. MC activates solenoid valve unit (SG) when the
signals from pressure sensor (boom raise) and
pump 1 delivery pressure sensor meet the
following conditions.
2. Solenoid valve unit (SG) delivers pilot pressure to
the main relief valve in control valve and
increases relief pressure. (Refer to Control Valve/
COMPONENT OPERATION.)
Conditions:
• Boom Raise Pressure Sensor: Outputting signals.
(The boom must be raised to a certain extent.)
(Reference: 1.7 MPa (17 kgf/cm2, 247 psi))
• Pump 1 delivery Pressure Sensor: High pressure.
(Reference: 31.3 MPa (320 kgf/cm2, 4550 psi))
• Arm Roll-In Pressure Sensor: Output zero. (The
control lever is in neutral.)
T2-2-46
SYSTEM / Control System
Pressure Sensor
Boom Raise
Arm Roll-In Pump 1 Delivery
Pressure Sensor
MC
T1V1-02-01-025C
T2-2-47
SYSTEM / Control System
Arm Regenerative Control
Operation:
1. MC activates solenoid valve unit (SC) so that
solenoid valve unit (SG) delivers pilot pressure
when the signals from pump 2 delivery pressure
sensor, swing pressure sensor, arm roll-in
pressure sensor and boom raise pressure sensor
meet the following conditions.
2. This pilot pressure shifts the arm regenerative
valve and the return circuit from arm cylinder rod
side to the hydraulic oil tank is closed.
3. Then, return oil from the arm cylinder rod side is
combined with pressure oil from the pump and is
routed to the cylinder bottom side so that arm
roll-in speed increases and prevents arm
hesitation. (Refer to Control Valve/ COMPONENT
OPERATION.)
4. At the same time, pilot pressure from solenoid
valve unit (SG) shifts the arm flow rate control
valve in arm 2 parallel circuit.
5. Therefore, as pressure oil through arm 2 parallel
circuit is controlled and delivered to boom 1,
boom raise speed is kept.
Conditions:
• Pump 1 and 2 Delivery Pressure Sensors:
Either pump 1 or 2 delivery pressure is low. (The
arm does not need much power to operate.)
(Reference: 16.5 MPa (168 kgf/cm2, 2400 psi) or
less)
• Arm Roll-In Pressure Sensor: High output. (The
arm control lever stroke is large.) (Reference: 0.5
MPa (5.1 kgf/cm2, 73 psi) or more)
• Swing or Boom Raise Pressure Sensor:
Outputting signal.
T2-2-48
SYSTEM / Control System
Pressure Sensor
Swing
Boom Raise
Arm Roll-In Pump 2 Delivery Pump 1 Delivery
Pressure Sensor Pressure Sensor
MC
Boom Cylinder
From Pump 1
SC
Boom 1
Boom 2
Arm Cylinder
Arm 1 Arm 2
T2-2-49
SYSTEM / Control System
Digging Regenerative Control
Operation:
1. MC activates solenoid valve unit (SF) when the
signals from pump 1, 2 delivery pressure sensors,
arm roll-in pressure sensor and boom raise
pressure sensor meet the following conditions.
2. When solenoid valve unit (SF) is activated, pilot
pressure shifts the digging regenerative valve.
3. Pressure oil in boom cylinder rod side is
combined with that from pump 2 and flows to the
arm 1 spool.
4. Pressure oil from the arm 1 spool is combined
with that from the arm 2 spool and flows to the
arm cylinder bottom side. Therefore, arm roll-in
speed increases.
Condition:
• Pump 1, 2 Delivery Pressure Sensors: High
pressure (Reference: 22 MPa (224 kgf/cm2, 3200
psi) or more)
• Arm Roll-In Pressure Sensor: Specified pressure
or higher (Reference: 2.7 MPa (28 kgf/cm2, 393
psi) or more)
T2-2-50
SYSTEM / Control System
Boom Raise
Arm Roll-In Pump 2 Delivery Pump 1 Delivery
Pressure Sensor Pressure Sensor
MC
Boom Cylinder
Digging
Solenoid Valve Unit Regenerative Valve
From Pump 1
SF
Boom 2
Arm Cylinder
Boom1
Arm 1
Arm 2
T1V1-02-01-023C
From Pump 2
T2-2-51
SYSTEM / Control System
Travel Motor Swash Angle Control
ZAXIS200-3, ZAXIS240-3
Operation:
• Slow
When the travel mode switch is in the SLOW
position, the travel motor swash angle is kept in
the maximum angle so that the travel speed is
slow.
• Fast
1. When the travel mode switch is in the HIGH
position and MC receives the signals from travel
pressure sensor, pump 1 and 2 delivery pressure
sensors and pump 1 and 2 control pressure
sensors under the following conditions, MC shifts
solenoid valve unit (SI).
2. When solenoid valve unit (SI) is shifted, pilot
pressure acts on the travel motor swash angle
control valve and reduces the swash angle to the
minimum, so that the travel speed increases.
Condition:
• Travel Pressure Sensor: Outputting signal.
• Front Attachment Pressure Sensor: OFF
• Pump 1, 2 Delivery Pressure Sensors: Delivery
pressure of either pump is low. (Reference: 24
MPa (245 kgf/cm2, 3490 psi) or less)
• Pumps 1, 2 Control Pressure Sensors: Either
pump control pressure is high. (Reference: 2.2
MPa (22 kgf/cm2, 320 psi) or more)
T2-2-52
SYSTEM / Control System
Pressure Sensor
Travel
Front Attachment
MC
Fast
Pump 2 Control
Pressure Sensor
Pump 1 Control
Pressure Sensor
Solenoid Valve Unit
SI
Swash Angle
Control Valve
T1V1-02-01-027C
T2-2-53
SYSTEM / Control System
ZAXIS270-3
Operation:
• Slow
When the travel mode switch is in the SLOW
position, the travel motor swash angle is kept in
the maximum angle so that the travel speed is
slow.
• Fast
1. When MC receives the signals from travel
pressure sensor, pump 1 and 2 delivery pressure
sensors, pump 1 and 2 control pressure sensors
under the following conditions with the travel
mode switch in the FAST position, MC shifts
solenoid valve unit (SI).
2. When solenoid valve unit (SI) is shifted, pilot
pressure acts on the travel motor swash angle
control valve and reduces the swash angle to the
minimum, so that the travel speed increases.
Condition:
• Travel Pressure Sensor: Outputting signal.
• Front Attachment Pressure Sensor: OFF
• Pump 1, 2 Delivery Pressure Sensors: Delivery
pressure of either pump is low. (Reference: 24
MPa (245 kgf/cm2, 3490 psi) or less)
• Pumps 1, 2 Control Pressure Sensors: Both pump
control pressures are high. (Reference: 2.2 MPa
(22 kgf/cm2, 320psi) or more)
T2-2-54
SYSTEM / Control System
Pressure Sensor
Travel
Front Attachment
MC
Fast
Pump 2 Control
Pressure Sensor
Pump 1 Control
Pressure Sensor
Solenoid Valve Unit
SI
Swash Angle
Control Valve
T1V1-02-01-027C
T2-2-55
SYSTEM / Control System
HSB Breaker Control (Optional)
Operation:
1. When selecting breaker 1 in monitor unit, MC
drives the selector valve control solenoid valve.
2. Pressure oil from the pilot pump flows through the
selector valve control solenoid valve, shifts the
selector valve, and the return circuit in breaker is
connected to the hydraulic oil tank.
3. At the same time, MC drives the secondary relief
control solenoid valve.
4. Pressure oil from the pilot pump flows the
secondary pilot relief pressure control solenoid
valve, shifts the secondary pilot relief pressure
control valve, and reduces relief set pressure in
breaker circuit.
5. When the maximum pump 2 flow rate limit control
solenoid valve is driven in the monitor unit, pump
2 flow rate can be adjusted finely.
T1V5-05-01-111C
T2-2-56
SYSTEM / Control System
Breaker
Monitor Unit
Dr.ZX
ICF
Secondary Pilot Relief
MC Pressure Control
Secondary Pilot
Solenoid Valve
Relief Pressure
Control Valve
Selector Valve
Secondary Pilot
Pressure Relief
Valve
Selector Valve
Control Solenoid
Valve
13
From Pilot
Pump
Attachment
Pilot Valve
Maximum Pump
2 Flow Rate Limit
Control Solenoid
Valve
From Pump 2
Flow Rate
Control Valve
in Signal
Control Valve
Pump 2
13
T1V1-02-01-033C
T2-2-57
SYSTEM / Control System
NPK Breaker Control (Optional)
Operation:
1. When selecting breaker 2 in monitor unit, MC
drives the selector valve control solenoid valve.
2. Pressure oil from the pilot pump flows through the
selector valve control solenoid valve, shifts the
selector valve, and the return circuit in breaker is
connected to the hydraulic oil tank.
3. At the same time, MC drives the accumulator
control solenoid valve.
4. Pressure oil from the pilot pump flows the
accumulator control solenoid valve and shifts the
accumulator control valve.
5. The accumulator is connected to either high
pressure side or low pressure side in breaker and
reduces shock of oil pressure while using the
breaker.
6. When the maximum pump 2 flow rate limit control
solenoid valve is driven in the monitor unit, pump
2 flow rate can be adjusted finely.
T1V5-05-01-112C
T2-2-58
SYSTEM / Control System
Breaker
Accumulator Accumulator
Control Valve (High Pressure)
Monitor Unit
ICF Dr.ZX
MC
Selector Valve Control
Solenoid Valve Accumulator
(Low Pressure)
Selector Valve
Accumulator Control
Solenoid Valve
13
From Pilot
Pump
Attachment
Pilot Valve
Maximum Pump
2 Flow Rate
Limit Control
Solenoid Valve
From Pump 2
Flow Rate
Control Valve in
Signal Control
Valve
Pump 2
13
T1V1-02-01-032C
T2-2-59
SYSTEM / Control System
Secondary Crusher Control (Optional)
T1V5-05-01-024C
T2-2-60
SYSTEM / Control System
Secondary
Pressure Sensor Crusher Cylinder
Travel
Swing
Boom Raise
Monitor Unit
Arm Roll-Out
Auxiliary
Dr. ZX
ICF
MC
Auxiliary Flow
Auxiliary Flow Rate Combiner Valve From Pump 1
Control Solenoid
Valve
13 14
Attachment
Pilot Valve
From Pilot
Pump
From
Pump 2 Bypass
Shut-Out Valve
14 13
T2-2-61
SYSTEM / Control System
Hydraulic Crusher Control (Optional)
T1V5-05-01-113C
T2-2-62
SYSTEM / Control System
Hydraulic
Crusher Cylinder
Pressure
Travel
Swing
Boom Raise
Monitor Unit Arm Roll-Out
Auxiliary
Dr.ZX
ICF
MC
Auxiliary Flow
Auxiliary Flow Combiner Valve From Pump 1
Rate Control
Solenoid Valve
13 14
Attachment
Pilot Valve From Pilot
Pump
From
Pump 2 Bypass
Shut-Out Valve
14 13
T2-2-63
SYSTEM / Control System
OTHER CONTROLS
Rear View Image Selection Control
T2-2-64
SYSTEM / Control System
MC
Monitor Unit
Rearview
Monitor
Image
T1V1-02-01-031C
T2-2-65
SYSTEM / Control System
Work Mode Control
The work modes include digging and front attachment
1 to 5 and are selected by the work mode on monitor
unit.
• Digging Mode:
Normal control is performed.
T2-2-66
SYSTEM / Control System
Travel Alarm Control (Only Machine Equipped
with Optional Parts)
Pressure Sensor
Travel
Travel Alarm
Device (Optional)
Buzzer
Deactivation
Switch (Optional)
T2-2-67
SYSTEM / Control System
Swing Alarm Control (Only Machines Equipped
with Optional Parts)
Pressure Sensor
Swing
Buzzer
Deactivation
Swing Alarm Switch (Optional)
Relay (Optional)
Buzzer
(Optional)
Rotation Light
(Optional)
T178-02-01-026C
T2-2-68
SYSTEM / ECM System
OUTLINE
ECM (Engine Control Module) receives the signals • The supply pump is driven by the engine and
from sensors and MC produces high-pressure fuel.
ECM processes and drives the two-way valve, suction • The common rail distributes high-pressure fuel
control valve and EGR motor in order to control the produced by the supply pump to the injector in
supply pump, injector pump and EGR (Exhaust Gas each engine cylinder.
Recirculation) valve. • The injector injects high-pressure from the
common rail.
• Fuel Injection Control
• Engine Start Control
• EGR Control
• Fuel Injection Amount Correction
• Engine Stop Control
Crank Speed Sensor
ECM
MC
Two-Way Valve
Common Rail
Pressure
Sensor
Suction Control
Valve
Common Rail
Supply Pump
Injector
Fuel Tank
T1GR-02-02-001C
T2-3-1
SYSTEM / ECM System
FUEL INJECTION CONTROL
ECM detects the engine running condition according to
the signals from each sensor and MC and controls fuel
injection amount, injection pressure, injection timing
and injection rate.
EGR Motor
ECM
MC
Suction Control
Valve
Common Rail
Supply Pump
Injector
Fuel Tank
T1GR-02-02-001C
T2-3-2
SYSTEM / ECM System
(Blank)
T2-3-3
SYSTEM / ECM System
Fuel Injection Amount Control
Operation:
1. ECM detects the engine speed according to the
signals from the crank speed sensor and cam
angle sensor.
2. MC calculate the target engine speed according
to the signals from the engine control dial,
sensors and switches and sends the signals to
ECM by using CAN communication.
(Refer to SYSTEM / Control System.)
3. ECM mainly controls fuel injection amount by
turning ON/OFF for two-way valve in injector
according to the engine speed and the signals
from MC.
T2-3-4
SYSTEM / ECM System
Pressure Sensor
Travel Crank Speed Sensor
Front Attachment
Cam Angle Sensor
Swing
Boom Raise Atmospheric Pressure Sensor
Arm Roll-In
Fuel Temperature Sensor
Auxiliary (Optional)
Coolant Temperature Sensor
Engine
Control Dial Intake-Air Temperature Sensor
EGR Motor
Power Mode MC
ECM
Switch
HP Mode
Monitor Unit
Common Rail
Digging Attachment
Mode Mode
Pump 2 Delivery
Pressure Sensor
Fuel Tank Supply Pump Injector
Pump 1 Delivery
Pressure Sensor
Oil Temperature
Sensor
Pump 1 Control
Pressure Sensor
T1V1-02-02-001C
Pump 2 Control
Pressure Sensor
T2-3-5
SYSTEM / ECM System
Fuel Injection Pressure Control
Operation:
1. ECM calculates fuel injection amount according to
the engine speed and the signals from MC by
using CAN communication. (Refer to the page on
Fuel Injection Amount Control.)
2. The common rail pressure sensor sends the
signals according to pressure in the common rail
to ECM.
3. ECM calculates the best fuel pressure in common
rail according to the engine speed, fuel injection
amount and the signals of common rail pressure.
ECM drives the suction control valve in supply
pump and supplies the best amount of fuel to the
common rail.
4. Fuel according to fuel pressure in the common rail
is supplied to the injector from the common rail so
that fuel injection pressure is controlled.
T2-3-6
SYSTEM / ECM System
Pressure Sensor
Travel Crank Speed Sensor
Front
Cam Angle Sensor
Swing
Boom Raise Atmospheric Pressure Sensor
Arm Roll-In
Fuel Temperature Sensor
Auxiliary (Optional)
Coolant Temperature Sensor
Engine
Control Dial
Intake-Air Temperature Sensor
Auto-Idle
Switch Boost Pressure Sensor
EGR Motor
Power Mode MC
ECM
Switch
HP Mode
Monitor Unit
Common Rail
Suction Control
Digging Valve
Attachment
Mode
Mode
Pump 2 Delivery
Pressure Sensor
Fuel Tank Supply Pump Injector
Pump 1 Delivery
Pressure Sensor
Oil Temperature
Sensor
Pump 1 Control
Pressure Sensor
T1V1-02-02-012C
Pump 2 Control
Pressure Sensor
T2-3-7
SYSTEM / ECM System
Fuel Injection Timing Control
Operation:
1. ECM calculates the fuel injection timing according
to engine speed and fuel injection amount.
2. ECM controls the two-way valve in injector by
turning ON/OFF according to fuel injection timing.
Operation:
1. The injector injects small amount of fuel (pilot
injection) first and ignites.
2. After igniting, the injector injects fuel (main
injection). ECM controls fuel injection timing and
fuel injection amount by turning the two-way valve
in injector ON/OFF.
Fuel Injection
1. The nozzle in injector is always pressured.
2. When turning the electromagnetic coil in two-way
valve ON, high-pressure fuel in the control
chamber returns to the fuel tank through orifice 1.
3. Therefore, the hydraulic pressure piston is raised
and the nozzle opens so that the injection starts.
4. When turning the electromagnetic coil in two-way
valve OFF, the valve is closed and the circuit to
fuel tank is closed. High-pressure fuel from the
common rail flows to the control chamber through
orifice 2.
5. Therefore, when high-pressure flows to the
control chamber, the hydraulic pressure piston is
lowered by pressure difference of movement of
hydraulic pressure piston so that injection stops.
T2-3-8
SYSTEM / ECM System
1. Two-Way Valve: ON 2. Injection Start
From ECM From ECM
Electromagnetic Coil
Two-Way Valve
Two-Way Valve
Valve
Control
Chamber
Hydraulic
Pressure Piston
Spring
Nozzle Nozzle
Electromagnetic Coil
Two-Way Valve Two-Way Valve
Valve
Orifice 2
Hydraulic Hydraulic
Pressure Piston Pressure Piston
Nozzle Nozzle
T1GR-02-02-012C
T2-3-9
SYSTEM / ECM System
ENGINE START CONTROL
Coolant From Terminal
Temperature Sensor #5 in Key Switch
Purpose: Controls time for continuity of electrical
current for the glow plug according to coolant
temperature and improves the starting of
engine.
From Battery
T2-3-10
SYSTEM / ECM System
(Blank)
T2-3-11
SYSTEM / ECM System
EGR (EXHAUST GAS RECIRCULATION)
CONTROL
Purpose: Re-circulates a part of exhaust gas in the
intake manifold and combines it with
intake-air. Therefore, combustion
temperature is lowered and generation of
oxide of nitrogen (NOx) is controlled.
Operation:
• EGR Gas Amount Control
1. ECM decides EGR gas amount according to
engine speed, fuel flow rate, coolant temperature,
atmospheric pressure and intake-air temperature.
2. ECM drives EGR motor, opens EGR valve and
sends EGR gas to the intake manifold in
response to engine condition so that EGR gas is
combined with intake-air.
3. At the same time, ECM detects the opening
amount of EGR valve by using EGR motor
position sensor.
• Lead Valve
Lead valve prevents fresh air from entering into the
EGR gas passage and EGR gas from flowing in
reverse direction.
Therefore, EGR gas flows to one direction and EGR
gas amount increases.
T2-3-12
SYSTEM / ECM System
To Intercooler
Exhaust
From Air Cleaner
Outlet of Coolant
Cooling System
Engine
Inlet of Coolant
EGR Valve
Intake Manifold
EGR Motor
Position
From Suction Sensor
Intercooler EGR Motor
Lead Valve
ECM
T2-3-13
SYSTEM / ECM System
FUEL INJECTION AMOUNT CORRECTION
Atmospheric
Pressure Sensor
Operation:
1. The atmospheric pressure sensor sends the
signals according to atmospheric condition to
ECM.
2. ECM calculates atmospheric pressure according
to the signals, controls the two-way valve in
injector and corrects fuel injection amount.
ECM
Two-Way
Valve
T1GR-02-02-002C
T2-3-14
SYSTEM / ECM System
(Blank)
T2-3-15
SYSTEM / ECM System
ENGINE STOP CONTROL
Operation:
1. When turning the emergency stop switch ON,
electrical current from the battery flows to the
terminal #1-47 in ECM through fuse #8 and ECM
main relay.
2. ECM stops injection of the injector and stops the
engine.
3. ECM is turned OFF after turning ECM main relay
OFF.
T2-3-16
SYSTEM / ECM System
Key Switch
Fuse #8
ECM Main
Relay
OFF
ECM
Emergency
#1-47
Stop Switch
T1V1-02-05-010C
T2-3-17
SYSTEM / ECM System
(Blank)
T2-3-18
SYSTEM / Hydraulic System
OUTLINE
The hydraulic system mainly consists of main circuit
and pilot circuit.
Main Circuit:
Pilot Circuit:
T2-4-1
SYSTEM / Hydraulic System
PILOT CIRCUIT
Outline:
• Pressure oil from the pilot pump is used in order
to the operation control circuit, pump control
circuit, valve control circuit, swing parking brake
release circuit, travel motor swash angle control
circuit and positioning circuit (optional).
T2-4-2
SYSTEM / Hydraulic System
*To Positioning
Control Valve Pump Control
Circuit
Maximum Pump 2
Flow Rate Control Torque Control
Solenoid Valve Solenoid Valve
Pilot Shut-Off
Valve
Signal Control Valve
SB ST
SA
Maximum Pump 1 Flow
Rate Control Solenoid
To Control Valve (Optional)
Valve Spool 2 1
Arm
Pilot Filter
T1V1-02-03-104C
T2-4-3
SYSTEM / Hydraulic System
Operation Control Circuit
• The pilot valve controls pressure oil from the pilot
pump and moves the spool in control valve.
• The signal control valve is provided between pilot
valve and control valve. The shockless valve
(boom lower circuit) built in the signal control
valve dampens quick spool movement in the
control valve. (Refer to the Signal Control Valve
in COMPONENT OPERATION.)
T2-4-4
SYSTEM / Hydraulic System
Positioning
Pilot Valve
(2-Piece Travel Pilot Valve Left Pilot Valve Right Pilot Valve
Boom only)
Shockless Valve
13 14
Pilot Shut-Off
Valve
9 10 11 12 4
Signal 3 2 1 8 7 6 5
Control Valve
10 11
9 12
7 8
1 2
1
Pilot Pump 6
5
Control Valve
14
13
Positioning Control
Valve (2-Piece
Boom only)
T1V1-02-03-011C
1 - Boom Raise 5- Left Swing 9 - Left Travel Forward 12 - Right Travel Reverse
2 - Boom Lower 6- Right Swing 10 - Left Travel Reverse 13 - Positioning Lower
3 - Arm Roll-Out 7- Bucket Roll-In 11 - Right Travel Forward 14 - Positioning Raise
4 - Arm Roll-In 8- Bucket Roll-Out
T2-4-5
SYSTEM / Hydraulic System
Pump Control Circuit (Refer to the Pump Device
section in COMPONENT OPERATION.)
T2-4-6
SYSTEM / Hydraulic System
Pilot
Shut-Off
Valve
Control Valve
Maximum Pump 2
Flow Rate Control Torque Control
Solenoid Valve Solenoid Valve
Pump 2 Pump 1
Pilot Pump
Pi Ppc
Ppc Pi T1V1-02-03-100C
T2-4-7
SYSTEM / Hydraulic System
Valve Control Circuit (Refer to the Control Valve
section in COMPONENT OPERATION.)
• Pilot pressure from the pilot valve, solenoid valve
units (SC, SF, SG), flow combiner valve control • Boom lower meter-in cut valve (7) controls boom
spool (2) in the signal control valve, bucket flow flow control valve (6). (Refer to the Boom Lower
control valve control spool (3) and arm flow control Meter-In Cut.)
valve control spool (1) controls the valves below.
T2-4-8
SYSTEM / Hydraulic System
Travel (Right) Arm Roll-In Boom Lower
Positioning
(2-Piece Boom only)
Auxiliary
Signal
Control
Valve
2
Arm Roll-In
Pilot
Pressure Auxiliary Flow
Combining
Boom Lower Pilot Solenoid Valve
Pressure
Positioning
19 20 3
Lower Pilot
Pressure
4
18
5
Arm Roll-In
17 Pilot Pressure
6
Auxiliary Flow 7
Control Solenoid
Valve 16 Boom Lower Pilot
Pressure
8
Solenoid
Valve Unit
SG
9
SF
10
SC
Pilot
Pump
Positioning Lower
Pilot Pressure
11
15 14 13 12
Arm Roll-In
Pilot
Pressure Boom Lower Pilot
Pressure T1V1-02-03-012C
1 - Arm Flow Control 6 - Boom Flow Control Valve 11 - Hose Rupture Valve (Boom) 16 - Arm Anti-Drift Valve
Valve Control Spool (Optional)
2 - Flow Combiner Valve 7 - Boom Lower Meter-In Cut 12 - Arm Regenerative Valve 17 - Hose Rupture Valve
Control Spool Valve (Arm) (Optional)
3 - Bucket Flow Control 8 - Boom Anti-Drift Valve 13 - Digging Regenerative Valve 18 - Auxiliary Flow Control
Valve Control Spool Valve
4 - Flow Combiner Valve 9 - Arm Flow Control Valve 14 - Arm Flow Control Valve (Arm 1) 19 - Main Relief Valve
(Arm 2)
5 - Bucket Flow Control 10 - Bypass Shut-Out Valve 15 - Hose Rupture Valve 20 - Auxiliary Flow Combining
Valve (Positioning) (Optional) Valve
T2-4-9
SYSTEM / Hydraulic System
Swing Parking Brake Release Circuit (Refer to
the Swing Device in COMPONENT OPERATION.)
• When operating the front attachment or swing,
pilot pressure SH is selected by the shuttle valve
in signal control valve and shifts the swing
parking brake release spool.
• As a result, the release signal pressure is
supplied to the swing motor and the swing
parking brake is released.
T2-4-10
SYSTEM / Hydraulic System
Signal
Control Valve Swing Parking Brake
Release Spool
Solenoid
Valve Unit
Control Valve Swing Motor
SI
Bypass
Shut-Out
Travel Motor Valve
Swash Angle
Control Valve
T2-4-11
SYSTEM / Hydraulic System
MAIN CIRCUIT
Outline:
• The main pump (pumps 1 and 2) draws hydraulic
oil from the hydraulic oil tank. Pump 1 delivers
pressure oil to the 4-spool side in control valve
and the positioning control valve (2-piece boom
only). Pump 2 delivers pressure oil to the 5-spool
side in control valve.
• Delivered pressure oil is supplied to the motor
and cylinder according to operation of the spool
in control valve.
• Return oil from the motor or cylinder returns to
the hydraulic oil tank through the control valve
and oil cooler.
• If oil temperature is low (with high viscosity), and
flow resistance is large in the oil cooler, the
bypass check valve opens and hydraulic oil
directly returns to the hydraulic oil tank.
T2-4-12
SYSTEM / Hydraulic System
Bucket Cylinder
Front Attachments
Control Valve
Boom Cylinder
4-Spool
Arm Cylinder Side
Travel (Left) Travel (Right)
Auxiliary Bucket
Boom 2 Boom 1
Arm 1 Arm 2
Swing
Positioning Cylinder
5-Spool (2-Piece Boom Only)
Side
Bypass Check
Valve
Swing Motor
Main
Pump 2 Pump 1 Pump
Oil
Cooler Positioning Control
Valve (2-Piece Boom
Only)
Suction Hydraulic
Filter Oil Tank
T1V1-02-03-103C
T2-4-13
SYSTEM / Hydraulic System
Neutral Circuit
• When the control lever is in neutral, pressure oil
from pumps 1 and 2 returns to the hydraulic oil
tank through the control valve.
T2-4-14
SYSTEM / Hydraulic System
Control Valve
Travel (Right)
Travel (Left)
Front
Attachment
Bucket Cylinder
Auxiliary
Bucket
Boom 2 Boom 1
Arm Cylinder
Boom Cylinder
Arm 1
Swing Motor
Arm 2
Swing
Pump 2 Pump 1
T1V1-02-03-001C
T2-4-15
SYSTEM / Hydraulic System
Combined Operation Circuit
• Swing and Boom Raise Operation
• When the boom is raised while swinging, pilot
pressure shifts the spools of swing, booms 1 and
2.
• Pressure oil from pump 1 flows to the boom
cylinder from the boom 1 spool through the
parallel circuit and raises the boom.
• Pressure oil from pump 2 flows to the swing
motor through the swing spool and swings.
• At the same time, pressure oil flows to the boom
cylinder from the boom 2 spool through the
parallel circuit, combines with pressure oil from
pump 1 and raises the boom.
T2-4-16
SYSTEM / Hydraulic System
Parallel
Circuit
Boom 2
Boom 1
Boom Cylinder
Swing Motor
Swing
Parallel
Circuit
Pump 2 Pump 1
T1V1-02-03-002C
T2-4-17
SYSTEM / Hydraulic System
• Travel and Arm Roll-In Operation
• When the arm is rolled in while traveling, pilot
pressure shifts the spools of travel, arms 1 and 2.
• At the same time, pilot pressure shifts the flow
combiner valve spool in signal control valve.
Pressure oil from the flow combiner valve spool
flows to the flow combiner valve and shifts the
flow combiner valve.
• Pressure oil from pump1 drives the right travel
motor through right travel spool.
• At the same time, pressure oil drives the left
travel motor through flow combiner valve and left
travel spool.
• Pressure oil from pump 2 flows to the arm
cylinder through the arm 1 spool and moves the
arm.
• Consequently, pressure oil pump 2 is used for the
arm. Pressure oil from pump 1 is equally supplied
to both left and right travel motors and the
machine can travel straight.
T2-4-18
SYSTEM / Hydraulic System
Travel (Right)
Travel (Left)
Arm Cylinder
Arm 1
Arm 2
Pump 2 Pump 1
T1V1-02-03-003C
T2-4-19
SYSTEM / Hydraulic System
Positioning Circuit (2-Piece Boom Only)
Neutral Circuit
• When the positioning lever is in neutral, pressure
oil from pump 1 returns to the hydraulic oil tank
through the control valve.
Positioning Cylinder
Single Operation Circuit
• During positioning operation, the spools of
bypass shut-out valve and positioning control
valve are shifted.
• Pressure oil from pump 1 flows to the spool in
positioning control valve and moves the
positioning cylinder.
T2-4-20
SYSTEM / Hydraulic System
Bypass Shut-Out
Valve
Positioning Cylinder
Pump 1
Positioning Control
Pressure
Positioning
Positioning Control Control
Valve Pressure
T1V1-02-03-014C
T2-4-21
SYSTEM / Hydraulic System
Auxiliary Circuit
• When the front attachment as a hydraulic breaker
is operated, pilot pressure from the pilot valve for NOTE: During operation of boom raise/lower, arm
front attachment shifts the auxiliary flow roll-in/out, bucket roll-in/out and right /left
combining valve and bypass shut-out valve. travel, pilot pressure from the signal
• Consequently, the neutral circuit in 4-spool side is control valve is supplied to port SN and the
blocked. Pressure oil from pump 1 through the auxiliary flow combining valve is not shifted.
auxiliary flow combining valve is combined with (Refer to the Control System in SYSTEM.)
pressure oil from pump 2 so that combined
pressure oil is supplied to the auxiliary spool.
T2-4-22
SYSTEM / Hydraulic System
SM
SN
Front
Attachment Neutral
Circuit
Auxiliary
Bypass Shut-Out
Valve
Pump 2 Pump 1
T1V1-02-03-004C
T2-4-23
SYSTEM / Hydraulic System
BOOM LOWER METER-IN CUT CONTROL
Purpose: During combined operation of boom lower
and arm, bucket, swing or travel with the
front attachment above the ground, pressure
oil to the boom cylinder from the pump is cut,
the boom falls due to own weight by using
the regenerative circuit, pressure oil is used
for other actuators and the control speed
increases.
Operation:
Boom Cylinder Bottom Pressure: High Pressure
(with the front attachment above the ground)
1. During combined operation of boom lower and
other actuators with the boom raised, the boom
lower meter-in cut valve is shifted by the boom
cylinder bottom pressure. As boom lower pilot
pressure does not act due to the boom lower
meter-in cut valve, the boom 2 spool does not
move.
2. The boom flow control valve (switch valve) is
closed by boom lower pilot pressure.
3. Back pressure in the boom flow control valve
(poppet valve) increases and the boom flow
control valve (poppet valve) is closed.
4. Pressure oil to the boom 1 spool from pump 1 is
cut by the boom flow control valve (poppet valve).
5. Pressure oil in the boom cylinder bottom side
flows to the boom cylinder rod side through the
boom 1 spool due to boom own weight.
6. As all pressure oil from pumps 1 and 2 is used for
actuators except the boom, the control speed
increases.
T2-4-24
SYSTEM / Hydraulic System
Boom 2
Arm
Cylinder
Boom 1
Arm 2
Pump 2 Pump 1
T1V1-02-03-005C
T2-4-25
SYSTEM / Hydraulic System
Boom Cylinder Bottom Pressure: Low Pressure
(Jack-Up)
T2-4-26
SYSTEM / Hydraulic System
Boom 2
Boom 1
Boom Cylinder
Pump 2 Pump 1
T1V1-02-03-006C
T2-4-27
SYSTEM / Hydraulic System
(Blank)
T2-4-28
SYSTEM / Electrical System
OUTLINE
The electrical circuit is broadly divided into the main
circuit, monitor circuit and control circuit.
• Main Circuit
The engine and accessory operation related circuit.
• Monitor Circuit
The electrical circuit group consists of the monitors,
sensors and switches, and displays the machine
operation status.
T2-5-1
SYSTEM / Electrical System
MAIN CIRCUIT
The major functions and circuits in the main circuit are
as follows.
• Accessory Circuit
Becomes operative when the key switch is turned
to the ACC position.
• Starting Circuit
Starts the engine. [Key Switch, Starter, Starter
Relay 2]
• Charging Circuit
Charges the batteries. [Alternator, (Regulator)]
• Wiper Circuit
Operate the intermittent operation of wiper and
the washer.
T2-5-2
SYSTEM / Electrical System
(Blank)
T2-5-3
SYSTEM / Electrical System
ELECTRIC POWER CIRCUIT (KEY
SWITCH: OFF)
The battery ground terminal is connected to the
vehicle frame. Current from the battery plus terminal
flows as shown below when the key switch is turned
OFF.
Battery
→Glow Plug Relay
↓ →Terminal #8: ECM Main Relay (Power)
(Power)
Fusible Link →Terminal #9: Radio (Backup Power)
→Key Switch (B)
Security Horn (Backup Power)
→Load Damp Relay
Security Horn Relay (Backup Power)
→Fuse Box
→Terminal #10: MC (Power), ICF (Power)
→Terminal #11: Horn Relay (Power)
→Terminal #19: Monitor Unit (Power)
→Terminal #20: Optional
T2-5-4
SYSTEM / Electrical System
Key Switch
Fusible Link
Battery
Horn Relay
Glow Relay
ECM Main Relay
Optional
MC, ICF
Monitor Unit
T1V1-02-05-001C
T2-5-5
SYSTEM / Electrical System
ACCESSORY CIRCUIT
T2-5-6
SYSTEM / Electrical System
Key Switch
Battery
Fuse Box
Cigarette Lighter
Auxiliary
T1V1-02-05-002C
T2-5-7
SYSTEM / Electrical System
STARTING CIRCUIT (KEY SWITCH:
START)
1. When the key switch is turned to the START 6. Consequently, the relay in starter is turned ON so
position, terminal B is connected to terminals M that the starter begins rotating.
and ST in the key switch.
7. On the other hand, current from key switch
2. As current from terminal M excites the battery terminal M flows to MC, ICF, the monitor unit and
relay, battery current is routed to starter terminal ECM through fuse #18 as a signal indicating that
B and starter relay 2 terminal B through the the key switch is in the ON or START position.
battery relay.
8. As soon as ECM receives this signal, ECM turns
3. Current from terminal ST flows to starter relay 2 the ECM main relay ON.
terminal S through the starter cut relay.
9. Current from the battery flows to ECM through
4. Current flows to the starter relay 2 coil and starter fuse #8 and the ECM main relay and the main
relay 2 is turned ON. power is turned ON.
5. Current flows to starter terminal C from starter 10. ECM makes the engine starting condition.
relay 2 terminal C.
T2-5-8
SYSTEM / Electrical System
Key Switch
Battery
Battery
Relay
Starter
C
C
Starter
Relay 2
ICF
ECM Main
Relay
EMC MC Monitor
Unit
T1V1-02-05-007C
T2-5-9
SYSTEM / Electrical System
Starter Relay 2 Operation
1. When the key switch is turned to the START 3. When this voltage increases up to 21 to 22 V,
position, key switch terminal B is connected to Zener diode (Z) is turned ON. Consequently,
terminal ST. Current is routed to the base in transistor (Q1) is turned ON. Then, current to the
transistor (Q2) through resistance R4 in starter base of transistor (Q2) does not flow and
relay 2. Then, transistor (Q2) is turned ON and transistor (Q2) is turned OFF. At this moment,
current flows to coil (L) in starter relay 2. starter terminal B is disconnected from terminal C
Therefore, starter terminal B is connected to and the starter is turned OFF.
terminal C and the starter is operated.
Condenser C1 is used to stabilize the operating
2. After the engine starts, the alternator starts voltage. Diode D4 protects the circuit in case the
generating electricity and voltage at starter relay battery terminals are reversely connected.
2 terminal R increases.
Starter Relay 2
S B
D3
(1)
R4 L
C
R3 (2) (1)
R2 Z D2 C
From Alternator R Q2 M
Q1 B
Terminal L
(2)
C1 C Starter
E D4
12V
B
ST
Battery
T107-04-04-003C
T2-5-10
SYSTEM / Electrical System
(Blank)
T2-5-11
SYSTEM / Electrical System
CHARGING CIRCUIT (KEY SWITCH: ON)
1. After the engine starts and the key switch is
released, the key switch moves to the ON
position. Monitor Unit
Alternator
NOTE: Monitor unit detects the alternator charging Alarm
according to power from the alternator and
turns the alternator alarm OFF.
T2-5-12
SYSTEM / Electrical System
Key Switch
Battery
To
Battery Monitor
Relay Unit,
ICF
Alternator
T1V1-02-05-003C
T2-5-13
SYSTEM / Electrical System
Alternator Operation
• The alternator consists of field coil FC, stator coil • At the beginning, no current is flowing through
SC and diode D. The regulator consists of field coil FC. When the rotor starts rotating,
transistors (T1 and T2), Zener diode ZD and alternate current is generated in stator coil SC by
resistances (R1 and R2). the rotor remanent magnetism.
• Alternator terminal B is connected to base B of • When current flows through field coil FC, the
transistor T1 through the circuit [B → R → RF rotor is further magnetized so that the generating
→ (R) → (R1)]. voltage increases. Thereby, current flowing
through field coil FC increases. Therefore,
• When the battery relay is ON, the battery voltage generating voltage increases further and the
is applied to base B of transistor T1 so that batteries start charging.
collector C is connected to emitter E. Therefore,
field coil FC is grounded through transistor T1.
Alternator
B R L Regulator
Battery RF (R) R3 R4 R5
Relay
R6
D
ZD
R2
Battery SC B
E
R1 C
T2
FC B
D1 C E
T1
(F)
(E)
E
T157-04-02-008C
T2-5-14
SYSTEM / Electrical System
Regulator Operation
• When generating voltage increases more than • When generating voltage decreases lower than
the set-voltage of Zener diode ZD, current flows the set-voltage of Zener diode ZD, transistor T2
to base B of transistor T2 and collector C is is turned OFF and transistor T1 is turned ON
connected to emitter E. again.
• Current which was routed to base B of transistor • Current flows through field coil FC and
T1 disappears due to transistor T2 operation so generating voltage at stator coil SC increases.
that transistor T1 is turned OFF. The above operation is repeated so that the
alternator generating voltage is kept constant.
• No current flows through filed coil FC and
generating voltage at stator coil SC decreases.
Battery Relay
RF R3 R4 R5
R6
ZD
R2
Battery B
SC
A E
C
FC T2
B
R1 C E
T1
(F) D1
(E)
E
T157-04-02-009C
T2-5-15
SYSTEM / Electrical System
SERGE VOLTAGE PREVENTION CIRCUIT
1. When the engine is stopped (key switch: OFF), 4. When the alternator is generating electricity,
current from key switch terminal M is generating current from alternator terminal L
disconnected and the battery relay is turned OFF. flows to monitor unit terminal #C-7. The monitor
unit connects terminal #A-12 to ground.
2. The engine continues to rotate due to inertia
force just after the key switch is turned OFF so 5. Current flows through the load damp relay
that the alternator continues to generate exciting circuit and the load damp relay is turned
electricity. ON.
3. As the generating current cannot flow to the 6. Accordingly, even if the key switch is turned OFF
battery, surge voltage arises in the circuit and while the engine is rotating, battery current
failures of the electronic components, such as continues to excite the battery relay through the
the controller, possibly cause. In order to prevent load damp relay. Until the alternator stops
the occurrence of surge voltage, the surge generating, the battery relay is kept ON.
voltage prevention circuit is provided.
T2-5-16
SYSTEM / Electrical System
Key Switch
Battery
Battery
Relay
Load
Damp
Relay
Alternator
Monitor Unit
#A-12 #C-7
T1V1-02-05-004C
T2-5-17
SYSTEM / Electrical System
PILOT SHUT-OFF CIRCUIT (KEY SWITCH:
ON)
T2-5-18
SYSTEM / Electrical System
Key Switch
Starter Cut
Relay
#6
Battery
Battery
Relay
Starter
Starter
Relay 2
Security
Relay Pilot Shut-Off
Lever
Pilot Shut-Off
Relay
Pilot Shut-Off
Solenoid Valve Monitor
Unit
T1V1-02-05-008C
T2-5-19
SYSTEM / Electrical System
SEUCURITY LOCK CIRCUIT
1. The monitor unit connects the ground circuit of
security relay and starter cut relay according to
the external warning signal or password input
error and the security relay and starter cut relay
are turned ON.
2. When the security relay is turned ON, as the
ground circuit of pilot shut-off solenoid valve is
disconnected, the pilot shut-off solenoid valve is
turned OFF so that pressure oil to the pilot valve
from the pilot pump is blocked.
3. When the starter cut relay is turned ON, key
switch terminal ST is disconnected from starter
relay 2 terminal S. Therefore, although the key
switch moves to the START position, the engine
does not start.
T2-5-20
SYSTEM / Electrical System
Key Switch
Starter Cut
Relay
Battery
Battery
Relay
Starter
Starter
Relay 2
Security
Relay Pilot Shut-Off
Lever
ICF
Pilot Shut-Off
Relay
Pilot Shut-Off
Solenoid Valve Monitor
Unit
T1V1-02-05-009C
T2-5-21
SYSTEM / Electrical System
ENGINE STOP CIRCUIT (KEY SWITCH:
OFF)
1. When the key switch is turned from the ON
position to the OFF position, the signal current
indicating that the key switch is ON stops flowing
from terminal M to ECM terminal #1-24.
T2-5-22
SYSTEM / Electrical System
Key Switch
Battery
ICF
ECM Main
Relay
ECM MC
Monitor Unit
1-24
T1V1-02-05-011C
T2-5-23
SYSTEM / Electrical System
SECURITY HORN CIRCUIT From Battery
Monitor Unit
Security Horn
Security Horn
Relay
T1V1-02-05-006C
T2-5-24
SYSTEM / Electrical System
(Blank)
T2-5-25
SYSTEM / Electrical System
WORKING LIGHT CIRCUIT
Working Light and Cab Light Circuit
1. When the working light switch moves to position
1, monitor unit terminal #B-20 receives the signal.
2. The monitor unit connects the ground circuit of
light relay 1.
3. Current from fuse #1 turns light relay 1 ON and
turns on the working light and cab light.
T2-5-26
SYSTEM / Electrical System
#B-20
Working Light
Switch #A-6
Working
Light Input
From
Battery
Fuse #1
Light Light
Relay 1 Relay 2
Cab Light
Working
Light
Boom Light
T1V1-02-05-012C
T2-5-27
SYSTEM / Electrical System
WIPER CIRCUIT
Intermittent Operation
Operation:
1. While pushing the wiper/washer switch, the
monitor unit receives the electrical signal from
the wiper/washer switch.
2. The monitor unit connects the ground circuit of
washer relay and the washer relay is turned ON.
3. When the washer relay is turned ON, current
from fuse #2 operates the washer motor and
washer liquid jets.
T2-5-28
SYSTEM / Electrical System
From
Battery
Fuse #2
Monitor Unit
Washer
Washer Relay
Wiper Motor
Washer Motor
Wiper Relay
T1V1-02-05-005C
T2-5-29
SYSTEM / Electrical System
(Blank)
T2-5-30
SECTION 3
COMPONENT OPERATION
CONTENTS
Group 1 Pump Device Group 4 Pilot Valve
Outline .....................................................T3-1-1 Outline .....................................................T3-4-1
Main Pump ...............................................T3-1-2 Operation .................................................T3-4-4
Regulator .................................................T3-1-6 Shockless Function
Solenoid Valve........................................T3-1-22 (Only for Travel Pilot Valve) ..................T3-4-12
Pilot Pump..............................................T3-1-24
Pump Delivery Pressure Sensor .............T3-1-24 Group 5 Travel Device
Pump Control Pressure Sensor ..............T3-1-24 Outline .....................................................T3-5-1
Travel Reduction Gear..............................T3-5-2
Group 2 Swing Device Travel Motor .............................................T3-5-4
Outline .....................................................T3-2-1 Parking Brake...........................................T3-5-6
Swing Reduction Gear..............................T3-2-2 Travel Mode Change ................................T3-5-8
Swing Motor .............................................T3-2-4 Travel Brake Valve .................................T3-5-12
Swing Parking Brake ................................T3-2-6
Group 6 Signal Control Valve
Valve Unit .................................................T3-2-8
Outline .....................................................T3-6-1
Swing Dampener Valve ..........................T3-2-13
Pilot Port ..................................................T3-6-2
Group 3 Control Valve Shuttle Valve ............................................T3-6-6
Outline .....................................................T3-3-1 Shockless Valve .....................................T3-6-10
Hydraulic Circuit .....................................T3-3-18 Pump 1 and Pump 2 Flow Rate
Flow Combiner Valve..............................T3-3-26 Control Valves ......................................T3-6-14
Main Relief Valve....................................T3-3-28 Bucket Flow Rate Control Valve Control Spool,
Overload Relief Valve .............................T3-3-30 Flow Combiner Valve Control Spool, Swing
Regenerative Valve ................................T3-3-32 Parking Brake Release Spool, Arm 1 Flow Rate
Anti-Drift Valve .......................................T3-3-36 Control Valve Control Spool ....................T3-6-16
Flow Rate Control Valve .........................T3-3-38
Digging Regenerative Valve....................T3-3-40
Boom Lower Meter-In Cut Valve .............T3-3-42
Auxiliary Flow Ccmbiner Valve
and Bypass Shut-Out Valve ..................T3-3-44
1V1T-3-1
Group 7 Others (Upperstructure)
Pilot Shut-Off Valve ..................................T3-7-1
Solenoid Valve..........................................T3-7-3
Hose Rupture Valve..................................T3-7-6
Pilot Relief Valve ....................................T3-7-12
1V1T-3-2
COMPONENT OPERATION / Pump Device
OUTLINE
The pump device consists of transmission (11), main
pump (pump 1(1), pump 2(2)) and pilot pump (3).
The engine output is transmitted to transmission (11)
via coupling (12). After being distributed by the gear,
the engine power drives pump 1(1), 2(2) and pilot
pump (3). Both reduction gear ratios of the main pump
and pilot pump (3) are 1:1. Transmission (11) is
lubricated with engine oil.
The main pump is a bent-axis type variable
displacement axial plunger pump. Pump 1(2) and
pump 2(2) are integrated as two units in one housing.
Pilot pump (3) is a gear pump.
Pump delivery pressure sensors (4, 5) and pump
control pressure sensors (8, 9) are installed in order to
control the pump and valve.
(Refer to the Control System section in SYSTEM.)
6 9
10
3 2 1
11
5 4
T1V1-03-01-004C
T3-1-1
COMPONENT OPERATION / Pump Device
MAIN PUMP
The main pump supplies pressure oil to actuate the
hydraulic components such as motors or cylinders.
The main pump consists of pump 1 and pump 2. Shaft
(3) is connected to each pump cylinder block (6) via
seven plungers (4). When shaft (3) is rotated with
cylinder block (6) together, plunger (4) oscillates in
cylinder block (6) and hydraulic oil is drawn and
delivered. Each main pump is equipped with a
regulator which controls the flow rate.
1 2
4
T178-03-01-005C
T3-1-2
COMPONENT OPERATION / Pump Device
Operational Principle
Plunger
Valve Plate
Shaft
Cylinder Block
T105-02-03-002C
T3-1-3
COMPONENT OPERATION / Pump Device
Increasing and Decreasing Flow Rate
Changing inclination of cylinder block (3) causes the
plunger (2) stroke to increase or decrease depending
on the slant angle in order to control the main pump
flow rate. Up-down movement of servo piston (6)
changes inclination of cylinder block (3). Servo piston
(6) is interlocked with valve plate (4) via pin (5). The
one end of cylinder block (3) is kept in contact with
the surface of valve plate (4) and slides along it.
T105-02-03-021C
6
T178-03-01-005C
2
4
T105-02-03-022C
T3-1-4
COMPONENT OPERATION / Pump Device
(Blank)
T3-1-5
COMPONENT OPERATION / Pump Device
REGULATOR
1 3 2 4
The regulator controls the main pump flow rate in
response to the various command signal pressures so Dr
that the pump driving power does not exceed the
engine power. Pump 1 and pump 2 are provided with
one regulator for each. The major parts of regulator
Pi
are spring (1), sleeve A (2), sleeve B (7), spool A (3),
spool B (6), piston (4), load piston (5), inner spring (8) Pd2 Air
and outer spring (9). According to the various Bleeding
Circuit
command signal pressures, the regulator opens or Pps
Dr
closes the circuit to servo piston (10), the inclination of
cylinder block (11) is changed and the pump flow rate Pd1
is controlled.
1- Spring 7- Sleeve B
2- Sleeve A 8- Inner Spring
3- Spool A 9- Outer Spring
4- Piston 10 - Servo Piston
5- Load Piston 11 - Cylinder Block
6- Spool B 12 - Link
T3-1-6
COMPONENT OPERATION / Pump Device
1 2 3 4
5 6 7 8 9
T178-03-01-006C
12
11
10
T178-03-01-005C
T3-1-7
COMPONENT OPERATION / Pump Device
Regulator Control Function
The regulator has the following four control functions.
T3-1-8
COMPONENT OPERATION / Pump Device
• Control by Pilot Pressure from Torque Control
Solenoid Valve
The main controller (MC) operates based on both
the engine target speed input data and actual speed Flow
Rate (Q)
information signals and outputs the signals to the
torque control solenoid valve. In response to the
signals from MC, the torque control solenoid valve
delivers torque control pilot pressure Pps to the
regulator. When receiving pilot pressure Pps, the
regulator reduces the pump flow rate. (Speed
Sensing Power Decrease Control: Slow Speed
Torque Increase Control)
(Refer to the Control System section.) 0 Pressure (P)
Pi
Pd2 Air
Bleeding
Circuit
Pps
Dr
Pd1
Pg
Increase Decrease
Cylinder Block Inclination T176-03-01-009C
T3-1-9
COMPONENT OPERATION / Pump Device
Control by Pump Control Pressure
Pg
10 12
Increase Decrease
Cylinder Block Inclination T176-03-01-009C
1 - Spring 4 - Piston
2 - Sleeve A 10 - Servo Piston
3 - Spool A 12 - Link
T3-1-10
COMPONENT OPERATION / Pump Device
To Hydraulic Primary Pilot Oil
1 Oil Tank Pressure 2 3 4 Pump Control
Pressure Pi
Torque
Control
Pressure
Pps
Pump 2
Delivery
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-008C
Torque
Control
Pressure
Pps
Pump 2
Delivery
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-009C
1 - Spring 3 - Spool A 10 - Servo Piston 12 - Link
2 - Sleeve A 4 - Piston
T3-1-11
COMPONENT OPERATION / Pump Device
Pg
10 12
Increase Decrease
Cylinder Block Inclination T176-03-01-009C
1 - Spring 4 - Piston
2 - Sleeve A 10 - Servo Piston
3 - Spool A 12 - Link
T3-1-12
COMPONENT OPERATION / Pump Device
To Hydraulic Primary Pilot
1 Oil Tank Pressure 2 3 4 Pump Control
Pressure Pi
Torque
Control
Pressure
Pps
Pump 2
Delivery
Pressure
Pd2
Pump 1
12
Delivery
Pressure
Pd1
10
T178-03-01-010C
Torque
Control
Pressure
Pps
Pump 2
Delivery
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-011C
T3-1-13
COMPONENT OPERATION / Pump Device
Control by Own or Opponent Pump Delivery
Pressure
T3-1-14
COMPONENT OPERATION / Pump Device
Torque
Control
Pressure
Pps
Pump 2
Delivery 8 9
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-012C
To Hydraulic Primary Pilot
5 Oil Tank Pressure 6 7 Pump Control
Pressure Pi
Torque
Control
Pressure
Pps
Pump 2
Delivery 8 9
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-013C
T3-1-15
COMPONENT OPERATION / Pump Device
5 6 Pg
10 12 8, 9
Increase Decrease
Cylinder Block Inclination T176-03-01-009C
T3-1-16
COMPONENT OPERATION / Pump Device
Torque
Control
Pressure
Pps
Pump 2
Delivery 8 9
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-014C
Torque
Control
Pressure
Pps
Pump 2
Delivery
8 9
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-015C
T3-1-17
COMPONENT OPERATION / Pump Device
Control by Pilot Pressure from Torque Control
Solenoid Valve
T3-1-18
COMPONENT OPERATION / Pump Device
Torque
Control
Pressure
Pps
Pump 2
Delivery 8 9
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-016C
Torque
Control
Pressure
Pps
Pump 2
Delivery 8 9
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-017C
5- Load Piston 7- Sleeve B 9 - Outer Spring 12 - Link
6- Spool B 8- Inner Spring 10 - Servo Piston
T3-1-19
COMPONENT OPERATION / Pump Device
Control by Pilot Pressure from Flow Rate Control
Solenoid Valve
Flow Rate (Q)
• Upper Limit Flow Rate Control (Pump 2 Only)
1. The maximum pump flow rate control solenoid
valve in pump control pressure Pi circuit is
activated by the signals from the main controller
(MC).
2. The maximum pump flow rate control solenoid
valve functions as a reducing valve and pump
control pressure Pi decreases.
3. Piston (4) is moved toward direction of the arrow 0 Pump Control Pressure (Pi)
by reduced pump control pressure Pi.
4. Piston (4) pushes spool A (3) and spring (1), until
Maximum Flow Rate
the force acting on piston (4) by pump control
pressure Pi becomes balanced with the spring (1) Flow Rate (Q) Upper Limit Flow Rate
force, spool A (3) moves toward direction of the
arrow.
5. As pump control pressure Pi has been reduced,
spool A (3) is moved in a shorter distance than
usual.
6. Due to the movement of spool A (3), the circuit
from the large chamber of servo piston (10) is
opened to the hydraulic oil tank.
7. As pilot pressure is constantly routed into the 0 Pressure (P)
small chamber of servo piston (10), servo piston
(10) is moved toward direction of the arrow.
Therefore, the cylinder block is rotated in the 1 3 2 4
maximum inclination direction and the pump flow Dr
rate increases.
8. The movement of cylinder block is transmitted to
sleeve A (2) via link (12). Sleeve A (2) is moved in
the same direction as spool A (3). Pi
9. When sleeve A (2) is moved by the same stroke Pd2 Air
as spool A (3), the open part between spool A (3) Bleeding
and sleeve A (2) is closed and pilot pressure to Circuit
Pps
the large chamber of servo piston (10) is blocked. Dr
10. Therefore, servo piston (10) is stopped and the Pd1
flow rate increase operation is completed.
11. Accordingly, pump control pressure Pi increases
in proportion to the stroke of control lever and the
pump delivery flow rate increases. However, as Pg
pump control pressure Pi is regulated, the strokes 10 12
of spool A (3) and servo piston (10) are reduced Increase Decrease
so that the maximum flow rate becomes less than Cylinder Block Inclination T176-03-01-009C
usual.
1 - Spring 4 - Piston
2 - Sleeve A 10 - Servo Piston
3 - Spool A 12 - Link
T3-1-20
COMPONENT OPERATION / Pump Device
Torque
Control
Pressure
Pps
Pump 2
Delivery
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-018C
Torque
Control
Pressure
Pps
Pump 2
Delivery
Pressure
Pd2
Pump 1 12
Delivery
Pressure
Pd1
10
T178-03-01-019C
1 - Spring 3 - Spool A 10 - Servo Piston 12 - Link
2 - Sleeve A 4 - Piston
T3-1-21
COMPONENT OPERATION / Pump Device
SOLENOID VALVE
The torque control solenoid valve and maximum pump
2 flow rate limit control solenoid valve are provided on
the pump 2 regulator. The torque control solenoid
valve supplies torque control pressure Pps to both the
pump 1 and pump 2 regulators and the pump flow rate
decreases. The maximum pump 2 flow rate limit
control solenoid valve reduces the pump control
pressure to the pump 2 regulator so that the upper
limit pump flow rate is limited.
Operation
1. When in neutral, port P is connected to the output
port through the notch on spool.
2. When the current flows to the solenoid from the
main controller (MC), the solenoid is magnetized
and pushes the piston.
3. The piston pushes the spool so that the output
port is connected to port T through the notch on
spool.
4. Thereby, pressure at the output port begins to
decrease.
5. As for the notch, spool diameter (B) is larger than
spool diameter (A).
6. Accordingly, when pressure at the output port
begins to decrease, the spool is move toward the
right side because of the force as P1 × B + S1 >
P1 × A + S2.
7. When pressure at the output port disappears and
when P1 × B + S1 becomes equal to P1 × A + S2,
the spool stops moving.
T3-1-22
COMPONENT OPERATION / Pump Device
Neutral state:
Operating state:
T3-1-23
COMPONENT OPERATION / Pump Device
PILOT PUMP
1
Inlet Port
Drive gear (1) is driven by the engine via the
2
transmission which in turn rotates driven gear (2) as
they are meshed together.
Outlet Port
T137-02-03-005C
T3-1-24
COMPONENT OPERATION / Swing Device
OUTLINE
The swing device consists of the valve unit, the swing The swing dampener valve is provided for the main
motor and the swing reduction gear. circuit in swing motor.
The valve unit prevents the cavitation and overloads in The swing dampener valve reduces shock when the
the swing circuit. swing brake is applied and also prevents aftershock.
The swing motor is a swash plate type axial plunger
motor (with built-in swing parking brake), which is
driven by pressure oil from the pump and is provided
with the swing reduction gear.
The swing reduction gear turns the swing motor with
large torque at a low speed and swings the upper-
structure.
Swing Motor
Swing Reduc-
tion Gear
T1V1-03-02-003C
T3-2-1
COMPONENT OPERATION / Swing Device
SWING REDUCTION GEAR
The swing reduction gear is a two-stage planetary re- Shaft (5) is engaged with the internal gear of swing
duction gear. bearing fixed to the undercarriage in order to swing the
Ring gear (3) is monolithically built with the housing upperstructure.
bolted to the upperstructure and does not allow to ro-
tate.
Shaft (1) of the swing motor turns first stage sun gear
(9), whose turning torque is transmitted to second
stage sun gear (7) through first stage planetary gear
(2) and first stage carrier (8).
Second stage sun gear (7) turns shaft (5) through
second stage planetary gear (4) and second stage
carrier (6).
1
1
9
9
2
2
8
8
3
3
7
7
4
4
6
6
5
5 T1V1-03-02-006C
T1V1-03-02-005C
1- Shaft (Swing Motor) 4 - Second Stage Planetary 7- Second Stage Sun Gear
Gear
2- First Stage Planetary Gear 5 - Shaft 8- First Stage Carrier
3- Ring Gear 6 - Second Stage Carrier 9- First Stage Sun Gear
T3-2-2
COMPONENT OPERATION / Swing Device
ZX270-3 class
1
9
2
8
7 3
6
4
T1V1-03-02-007C
5
1- Shaft (Swing Motor) 4 - Second Stage Planetary 7- Second Stage Sun Gear
Gear
2- First Stage Planetary Gear 5 - Shaft 8- First Stage Carrier
3- Ring Gear 6 - Second Stage Carrier 9- First Stage Sun Gear
T3-2-3
COMPONENT OPERATION / Swing Device
SWING MOTOR
The swing motor consists of swash plate (9), rotor (12), When pressure oil is supplied from the pump, plunger
valve plate (13), housing (11) and swing parking brake (6) is pushed. Shoe (10) at the top of plunger (6)
(springs (1), brake pistons (2), plate (3), friction plate slides over swash plate (9) so that rotor (12) rotates.
(5) and swing parking brake selection valve (4)). The top of shaft (8) is splined to the first stage sun
Shaft (8) is splined to rotor (12) into which plunger (6) gear of swing reduction gear. Therefore, the rotation of
is inserted. shaft (8) is transmitted to the swing reduction gear.
1
13
2
12 3
4
11
5
10
6
9 7
T1V1-03-02-008C
T3-2-4
COMPONENT OPERATION / Swing Device
ZX270-3 class
13
12
5
4
6
11
10 9 8 T1V7-03-02-001C
T3-2-5
COMPONENT OPERATION / Swing Device
SWING PARKING BRAKE
The swing parking brake is a wet type multi-plate disc
brake and a negative mechanism that releases the
brake when brake release pressure acts in the brake
piston chamber.
The brake release pressure is supplied from the pilot
pump only when either swing or front attachment is
operated.
In other cases (including engine stopping), the brake
release pressure returns to the hydraulic oil tank, so
that the brake is applied automatically by the spring.
T3-2-6
COMPONENT OPERATION / Swing Device
8
3
7 4
Port SH (Brake Re-
lease Pressure)
6
5
T178-03-02-003C
ZX270-3 class
1
4
6
3
7
8 T1V7-03-02-002C
T3-2-7
COMPONENT OPERATION / Swing Device
VALVE UNIT
The valve unit consists of make-up valve and relief
valve.
The make-up valve prevents cavitation in the circuit
and the relief valve prevents surge pressure and Relief valve
overloads in the circuit.
Make-Up Valve
Make-Up Valve
During swing stopping operation, the swing motor is
driven by the inertial force of swing frame. The swing
motor is turned forcibly in excess of oil pressure from
the pump, so that cavitation may be generated in the
motor. Port M
In order to avoid this cavitation, when pressure in the
swing circuit becomes lower than that in the return
Control Valve
circuit (port M), the poppet opens to draw hydraulic oil
and compensates the lack of oil feed.
T107-02-04-013C
Control Valve
Poppet
Port M
T1V1-03-02-011C
Relief Valve
T3-2-8
COMPONENT OPERATION / Swing Device
ZX270-3 class
Control Valve
Poppet
Make-Up
Make-Up Valve
Valve
Port M
Relief T1V7-03-02-003C
Valve
T3-2-9
COMPONENT OPERATION / Swing Device
Relief Valve
During starting or stopping swing operation, oil pres-
sure in the swing circuit becomes high. The relief
valve prevents the circuit pressure from rising higher
than the set-pressure.
HP
LP
Oil Chamber A
T3-2-10
COMPONENT OPERATION / Swing Device
ZX270-3 class
• Low Pressure Relief Operation (Shockless Func- • High Pressure Relief Operation (Overload Preven-
tion): tion):
1. Pressure at port HP (swing circuit) is routed into 1. After the piston is moved full stroke, the circuit
oil chamber through the poppet orifice. pressure becomes the relief set-pressure.
2. When pressure in the oil chamber is increased 2. If pressure at port HP increases more than the
more than the force of spring 2, the piston moves spring 1 set-pressure, the poppet is unseated
to the left. pressure oil flows to port HP.
3. As long as the piston keeps moving, a pressure 3. When pressure at port HP is reduced to the
difference is developed between the front and the specified level, the poppet is seated by the spring
rear of poppet. When this pressure difference is 1 force.
increased more than spring force, the poppet is
unseated and pressure oil flows to port LP.
4. When the piston is moved full stroke, the pres-
sure difference between the front and the rear of
poppet disappears and the poppet is seated.
Hp
Poppet
T107-02-04-020C
T3-2-11
COMPONENT OPERATION / Swing Device
(Blank)
T3-2-12
COMPONENT OPERATION / Swing Device
SWING DAMPENER VALVE
The swing dampener valve is provided for the main
circuit in swing motor.
The swing dampener valve consists of two combina-
tion valves. As the dampener valve relieves swing
brake pressure (aftershock pressure) with the control
lever released to the circuit in opposite side
(low-pressure side), the dampener valve reduces the
shock when applying the swing brake and prevents
the aftershock.
Combination
Valve
Swing Dampener
Valve
T1V1-03-02-003C
T3-2-13
COMPONENT OPERATION / Swing Device
Operation
T3-2-14
COMPONENT OPERATION / Swing Device
Swing Motor
AM BM
6 7
Plug Chamber N
Chamber M
1 2 3 4 5
Chamber N
7 6
Control Valve
T1V1-03-02-013C
T3-2-15
COMPONENT OPERATION / Swing Device
• Output Curve: Between B and C (Pressure begins
to decrease)
When the swing motor rotation due to the inertia force
of machine is reduced, pressure at port BM decreases.
At this time, combination valve (A) functions as the
following.
T3-2-16
COMPONENT OPERATION / Swing Device
Swing Motor
AM BM
6 7
Chamber N
1 M室 2 3 4 5
Chamber N
7 6
Control Valve
T1V1-03-02-014C
T3-2-17
COMPONENT OPERATION / Swing Device
• Output Curve: Between C and D (Pressure at port
BM decreases)
When the swing motor rotation is reduced more,
pressure at port BM decreases more. At this time,
combination valve (B) functions as the following.
T3-2-18
COMPONENT OPERATION / Swing Device
Swing Motor
AM BM
6 7
Chamber N
1 Chamber M 2 3 4 5
Combination Valve(B)
Chamber N
7 6
Control Valve
T1V1-03-02-015C
T3-2-19
COMPONENT OPERATION / Swing Device
• Output Curve: Between D and E (During aftershock)
When the swing motor stops rotating, aftershock
pressure appears at port AM and pressure at port AM
increases. (Port AM: High Pressure, Port BM: Low
Pressure) Pressure at Port AM
At this time, combination valves (A, B) function as the
following. Pressure (P)
T3-2-20
COMPONENT OPERATION / Swing Device
Swing Motor
AM BM
1 2
Control Valve
T1V1-03-02-016C
1- Poppet 2- Ball
T3-2-21
COMPONENT OPERATION / Swing Device
(Blank)
T3-2-22
COMPONENT OPERTATION / Control Valve
OUTLINE
The control valve controls the pressure, flow rate, and As for the spools, in the 4-spool section, right travel,
flow direction in the hydraulic circuit. bucket, boom 1 and arm 2 are arranged in that order
The major parts are main relief valve, overload relief as viewed from the machine front. In the 5-spool
valve, flow combiner valve, anti-drift valve, flow control section, left travel, auxiliary, boom 2, arm 1 and swing
valve, regenerative valve, digging regenerative valve, are arranged in that order as viewed from the machine
boom lower meter-in cut valve, auxiliary combining front.
valve, bypass shut-out valve and spools. The spools
are operated by pilot oil pressure.
4-Spool
Control Valve Travel Section
Main Relief Valve (Right)
Machine Bucket
Upper
Boom 1
Arm 2
Machine
Front
Travel
(Left)
Auxiliary
Boom 2
Arm 1
Swing
5-Spool
Section
T1V1-03-03-072C
Machine Front
T178-03-03-370
T3-3-1
COMPONENT OPERTATION / Control Valve
Layout of Control Valve
1 2 3 4 5 6 7 8 9 10 11
12
42
13
14
41
40 15
16
39
17
38
18
19
20
37
36
35 21
34
22
23
33
32 24
31 30 29 28 27 26 25
T1V1-03-03-021C
T3-3-2
COMPONENT OPERTATION / Control Valve
4-Spool Section
Arm Roll-In
Pressure Sensor 18 19, 22 13
10, 11
23
15, 17
16
7
1- Load Check Valve (Left 12 - Bucket Regenerative Valve 23 - Arm 2 Flow Rate Control 34 - Arm Anti-Drift Valve
Travel Parallel Circuit) Valve (Switch Valve) (Switch Valve)
2 - Check Valve (Main 13 - Overload Relief Valve 24 - Load Check Valve (Arm 2 35 - Overload Relief Valve
Relief Circuit) (Bucket: Rod Side) Tandem Circuit) (Arm: Bottom Side)
3 - Main Relief Valve 14 - Overload Relief Valve 25 - Bypass Shut-Out Valve 36 - Arm Anti-Drift Valve (Check
(Bucket: Bottom Side) Valve)
4- Check Valve (Auxiliary 15 - Boom Flow Control Valve 26 - Arm 2 Flow Rate Control 37 - Overload Relief Valve
Combining Valve Circuit) (Poppet Valve) Valve (Poppet Valve) (Arm: Rod Side)
5 - Auxiliary Flow Combiner 16 - Boom Lower Meter-In Cut 27 - Arm Regenerative Valve 38 - Check Valve (Digging
Valve Valve Regenerative Circuit)
6 - Check Valve (Flow 17 - Boom Flow Rate Control 28 - Digging Regenerative 39 - Load Check Valve (Boom 2
Combiner Valve Circuit) Valve (Switch Valve) Valve Parallel Circuit)
7 - Flow Combiner Valve 18 - Overload Relief Valve (Boom: 29 - Load Check Valve (Digging 40 - Auxiliary Flow Rate Control
Bottom Side) Regenerative Circuit) Valve (Poppet Valve)
8- Load Check Valve 19 - Boom Anti-Drift Valve (Check 30 - Arm 1 Flow Rate Control 41 - Auxiliary Flow Rate Control
(Orifice) (Bucket) Valve) Valve (Poppet Valve) Valve (Switch Valve)
9 - Check Valve (Main 20 - Overload Relief Valve (Boom: 31 - Load Check Valve (Swing 42 - Load Check Valve (Left
Relief Circuit) Rod Side) Circuit) Travel Tandem Circuit)
10 - Bucket Flow Rate 21 - Boom Regenerative Valve 32 - Arm 1 Flow Rate Control
Control Valve (Poppet Valve (Switch Valve)
Valve)
11 - Bucket Flow Rate 22 - Boom Anti-Drift Valve (Switch 33 - Load Check Valve (Arm
Control Valve (Switch Valve) Regenerative Circuit)
Valve)
T3-3-3
COMPONENT OPERTATION / Control Valve
1 2 3 4 5 6 7 8 9 10 11
12
42
13
14
41
15
40
16
39
17
38
18
19
20
37
36
35 21
34
22
23
33
32 24
31 30 29 28 27 26 25
T1V1-03-03-021C
T3-3-4
COMPONENT OPERTATION / Control Valve
5-Spool Section
3
37 34, 36
30, 32
40, 41 T1V1-03-03-072C
28
35
1- Load Check Valve (Left 12 - Bucket Regenerative Valve 23 - Arm 2 Flow Rate Control 34 - Arm Anti-Drift Valve
Travel Parallel Circuit) Valve (Switch Valve) (Switch Valve)
2 - Check Valve (Main 13 - Overload Relief Valve 24 - Load Check Valve (Arm 2 35 - Overload Relief Valve
Relief Circuit) (Bucket: Rod Side) Tandem Circuit) (Arm: Bottom Side)
3 - Main Relief Valve 14 - Overload Relief Valve 25 - Bypass Shut-Out Valve 36 - Arm Anti-Drift Valve (Check
(Bucket: Bottom Side) Valve)
4- Check Valve (Auxiliary 15 - Boom Flow Control Valve 26 - Arm 2 Flow Rate Control 37 - Overload Relief Valve
Combining Valve Circuit) (Poppet Valve) Valve (Poppet Valve) (Arm: Rod Side)
5 - Auxiliary Flow Combiner 16 - Boom Lower Meter-In Cut 27 - Arm Regenerative Valve 38 - Check Valve (Digging
Valve Valve Regenerative Circuit)
6 - Check Valve (Flow 17 - Boom Flow Rate Control 28 - Digging Regenerative 39 - Load Check Valve (Boom 2
Combiner Valve Circuit) Valve (Switch Valve) Valve Parallel Circuit)
7 - Flow Combiner Valve 18 - Overload Relief Valve (Boom: 29 - Load Check Valve (Digging 40 - Auxiliary Flow Rate Control
Bottom Side) Regenerative Circuit) Valve (Poppet Valve)
8- Load Check Valve 19 - Boom Anti-Drift Valve (Check 30 - Arm 1 Flow Rate Control 41 - Auxiliary Flow Rate Control
(Orifice) (Bucket) Valve) Valve (Poppet Valve) Valve (Switch Valve)
9 - Check Valve (Main 20 - Overload Relief Valve (Boom: 31 - Load Check Valve (Swing 42 - Load Check Valve (Left
Relief Circuit) Rod Side) Circuit) Travel Tandem Circuit)
10 - Bucket Flow Rate 21 - Boom Regenerative Valve 32 - Arm 1 Flow Rate Control
Control Valve (Poppet Valve (Switch Valve)
Valve)
11 - Bucket Flow Rate 22 - Boom Anti-Drift Valve (Switch 33 - Load Check Valve (Arm
Control Valve (Switch Valve) Regenerative Circuit)
Valve)
T3-3-5
COMPONENT OPERTATION / Control Valve
1 2 3 4 5 6 7 8 9 10 11
12
42
13
14
41
15
40
16
39
17
38
18
19
20
37
36
35 21
34
22
23
33
32 24
31 30 29 28 27 26 25
T1V1-03-03-021C
T3-3-6
COMPONENT OPERTATION / Control Valve
3
A B
Cross Section C-C
C C
D D
E E
F F 4
G G
H H
I I
5
J J
7
T1V1-03-03-026 T1V1-03-03-003
A B
28
21
27
29
T1V1-03-03-001 T1V1-03-03-002
1- Load Check Valve (Left 12 - Bucket Regenerative Valve 23 - Arm 2 Flow Rate Control 34 - Arm Anti-Drift Valve
Travel Parallel Circuit) Valve (Switch Valve) (Switch Valve)
2 - Check Valve (Main 13 - Overload Relief Valve 24 - Load Check Valve (Arm 2 35 - Overload Relief Valve
Relief Circuit) (Bucket: Rod Side) Tandem Circuit) (Arm: Bottom Side)
3 - Main Relief Valve 14 - Overload Relief Valve 25 - Bypass Shut-Out Valve 36 - Arm Anti-Drift Valve (Check
(Bucket: Bottom Side) Valve)
4- Check Valve (Auxiliary 15 - Boom Flow Control Valve 26 - Arm 2 Flow Rate Control 37 - Overload Relief Valve
Combining Valve Circuit) (Poppet Valve) Valve (Poppet Valve) (Arm: Rod Side)
5 - Auxiliary Flow Combiner 16 - Boom Lower Meter-In Cut 27 - Arm Regenerative Valve 38 - Check Valve (Digging
Valve Valve Regenerative Circuit)
6 - Check Valve (Flow 17 - Boom Flow Rate Control 28 - Digging Regenerative 39 - Load Check Valve (Boom 2
Combiner Valve Circuit) Valve (Switch Valve) Valve Parallel Circuit)
7 - Flow Combiner Valve 18 - Overload Relief Valve (Boom: 29 - Load Check Valve (Digging 40 - Auxiliary Flow Rate Control
Bottom Side) Regenerative Circuit) Valve (Poppet Valve)
8- Load Check Valve 19 - Boom Anti-Drift Valve (Check 30 - Arm 1 Flow Rate Control 41 - Auxiliary Flow Rate Control
(Orifice) (Bucket) Valve) Valve (Poppet Valve) Valve (Switch Valve)
9 - Check Valve (Main 20 - Overload Relief Valve (Boom: 31 - Load Check Valve (Swing 42 - Load Check Valve (Left
Relief Circuit) Rod Side) Circuit) Travel Tandem Circuit)
10 - Bucket Flow Rate 21 - Boom Regenerative Valve 32 - Arm 1 Flow Rate Control
Control Valve (Poppet Valve (Switch Valve)
Valve)
11 - Bucket Flow Rate 22 - Boom Anti-Drift Valve (Switch 33 - Load Check Valve (Arm
Control Valve (Switch Valve) Regenerative Circuit)
Valve)
T3-3-7
COMPONENT OPERTATION / Control Valve
1 2 3 4 5 6 7 8 9 10 11
12
42
13
14
41
15
40
16
39
17
38
18
19
20
37
36
35 21
34
22
23
33
32 24
31 30 29 28 27 26 25
T1V1-03-03-021C
T3-3-8
COMPONENT OPERTATION / Control Valve
13
10
41
11
14
40
T1V1-03-03-005
T1V1-03-03-004 12
1- Load Check Valve (Left 12 - Bucket Regenerative Valve 23 - Arm 2 Flow Rate Control 34 - Arm Anti-Drift Valve
Travel Parallel Circuit) Valve (Switch Valve) (Switch Valve)
2 - Check Valve (Main 13 - Overload Relief Valve 24 - Load Check Valve (Arm 2 35 - Overload Relief Valve
Relief Circuit) (Bucket: Rod Side) Tandem Circuit) (Arm: Bottom Side)
3 - Main Relief Valve 14 - Overload Relief Valve 25 - Bypass Shut-Out Valve 36 - Arm Anti-Drift Valve (Check
(Bucket: Bottom Side) Valve)
4- Check Valve (Auxiliary 15 - Boom Flow Control Valve 26 - Arm 2 Flow Rate Control 37 - Overload Relief Valve
Combining Valve Circuit) (Poppet Valve) Valve (Poppet Valve) (Arm: Rod Side)
5 - Auxiliary Flow Combiner 16 - Boom Lower Meter-In Cut 27 - Arm Regenerative Valve 38 - Check Valve (Digging
Valve Valve Regenerative Circuit)
6 - Check Valve (Flow 17 - Boom Flow Rate Control 28 - Digging Regenerative 39 - Load Check Valve (Boom 2
Combiner Valve Circuit) Valve (Switch Valve) Valve Parallel Circuit)
7 - Flow Combiner Valve 18 - Overload Relief Valve (Boom: 29 - Load Check Valve (Digging 40 - Auxiliary Flow Rate Control
Bottom Side) Regenerative Circuit) Valve (Poppet Valve)
8- Load Check Valve 19 - Boom Anti-Drift Valve (Check 30 - Arm 1 Flow Rate Control 41 - Auxiliary Flow Rate Control
(Orifice) (Bucket) Valve) Valve (Poppet Valve) Valve (Switch Valve)
9 - Check Valve (Main 20 - Overload Relief Valve (Boom: 31 - Load Check Valve (Swing 42 - Load Check Valve (Left
Relief Circuit) Rod Side) Circuit) Travel Tandem Circuit)
10 - Bucket Flow Rate 21 - Boom Regenerative Valve 32 - Arm 1 Flow Rate Control
Control Valve (Poppet Valve (Switch Valve)
Valve)
11 - Bucket Flow Rate 22 - Boom Anti-Drift Valve (Switch 33 - Load Check Valve (Arm
Control Valve (Switch Valve) Regenerative Circuit)
Valve)
T3-3-9
COMPONENT OPERTATION / Control Valve
1 2 3 4 5 6 7 8 9 10 11
12
42
13
14
41
15
40
16
39
17
38
18
19
20
37
36
35 21
34
22
23
33
32 24
31 30 29 28 27 26 25
T1V1-03-03-021C
T3-3-10
COMPONENT OPERTATION / Control Valve
19
39
16
17
15
38 28 26
21 20
T1V1-03-03-006 T1V1-03-03-007
1- Load Check Valve (Left 12 - Bucket Regenerative Valve 23 - Arm 2 Flow Rate Control 34 - Arm Anti-Drift Valve
Travel Parallel Circuit) Valve (Switch Valve) (Switch Valve)
2 - Check Valve (Main 13 - Overload Relief Valve 24 - Load Check Valve (Arm 2 35 - Overload Relief Valve
Relief Circuit) (Bucket: Rod Side) Tandem Circuit) (Arm: Bottom Side)
3 - Main Relief Valve 14 - Overload Relief Valve 25 - Bypass Shut-Out Valve 36 - Arm Anti-Drift Valve (Check
(Bucket: Bottom Side) Valve)
4- Check Valve (Auxiliary 15 - Boom Flow Control Valve 26 - Arm 2 Flow Rate Control 37 - Overload Relief Valve
Combining Valve Circuit) (Poppet Valve) Valve (Poppet Valve) (Arm: Rod Side)
5 - Auxiliary Flow Combiner 16 - Boom Lower Meter-In Cut 27 - Arm Regenerative Valve 38 - Check Valve (Digging
Valve Valve Regenerative Circuit)
6 - Check Valve (Flow 17 - Boom Flow Rate Control 28 - Digging Regenerative 39 - Load Check Valve (Boom 2
Combiner Valve Circuit) Valve (Switch Valve) Valve Parallel Circuit)
7 - Flow Combiner Valve 18 - Overload Relief Valve (Boom: 29 - Load Check Valve (Digging 40 - Auxiliary Flow Rate Control
Bottom Side) Regenerative Circuit) Valve (Poppet Valve)
8- Load Check Valve 19 - Boom Anti-Drift Valve (Check 30 - Arm 1 Flow Rate Control 41 - Auxiliary Flow Rate Control
(Orifice) (Bucket) Valve) Valve (Poppet Valve) Valve (Switch Valve)
9 - Check Valve (Main 20 - Overload Relief Valve (Boom: 31 - Load Check Valve (Swing 42 - Load Check Valve (Left
Relief Circuit) Rod Side) Circuit) Travel Tandem Circuit)
10 - Bucket Flow Rate 21 - Boom Regenerative Valve 32 - Arm 1 Flow Rate Control
Control Valve (Poppet Valve (Switch Valve)
Valve)
11 - Bucket Flow Rate 22 - Boom Anti-Drift Valve (Switch 33 - Load Check Valve (Arm
Control Valve (Switch Valve) Regenerative Circuit)
Valve)
T3-3-11
COMPONENT OPERTATION / Control Valve
1 2 3 4 5 6 7 8 9 10 11
12
42
13
14
41
15
40
16
39
17
38
18
19
20
37
36
35 21
34
22
23
33
32 24
31 30 29 28 27 26 25
T1V1-03-03-021C
T3-3-12
COMPONENT OPERTATION / Control Valve
34
18
27
36
32 24
31
23
30
35
T1V1-03-03-008 T1V1-03-03-009
1- Load Check Valve (Left 12 - Bucket Regenerative Valve 23 - Arm 2 Flow Rate Control 34 - Arm Anti-Drift Valve
Travel Parallel Circuit) Valve (Switch Valve) (Switch Valve)
2 - Check Valve (Main 13 - Overload Relief Valve 24 - Load Check Valve (Arm 2 35 - Overload Relief Valve
Relief Circuit) (Bucket: Rod Side) Tandem Circuit) (Arm: Bottom Side)
3 - Main Relief Valve 14 - Overload Relief Valve 25 - Bypass Shut-Out Valve 36 - Arm Anti-Drift Valve (Check
(Bucket: Bottom Side) Valve)
4- Check Valve (Auxiliary 15 - Boom Flow Control Valve 26 - Arm 2 Flow Rate Control 37 - Overload Relief Valve
Combining Valve Circuit) (Poppet Valve) Valve (Poppet Valve) (Arm: Rod Side)
5 - Auxiliary Flow Combiner 16 - Boom Lower Meter-In Cut 27 - Arm Regenerative Valve 38 - Check Valve (Digging
Valve Valve Regenerative Circuit)
6 - Check Valve (Flow 17 - Boom Flow Rate Control 28 - Digging Regenerative 39 - Load Check Valve (Boom 2
Combiner Valve Circuit) Valve (Switch Valve) Valve Parallel Circuit)
7 - Flow Combiner Valve 18 - Overload Relief Valve (Boom: 29 - Load Check Valve (Digging 40 - Auxiliary Flow Rate Control
Bottom Side) Regenerative Circuit) Valve (Poppet Valve)
8- Load Check Valve 19 - Boom Anti-Drift Valve (Check 30 - Arm 1 Flow Rate Control 41 - Auxiliary Flow Rate Control
(Orifice) (Bucket) Valve) Valve (Poppet Valve) Valve (Switch Valve)
9 - Check Valve (Main 20 - Overload Relief Valve (Boom: 31 - Load Check Valve (Swing 42 - Load Check Valve (Left
Relief Circuit) Rod Side) Circuit) Travel Tandem Circuit)
10 - Bucket Flow Rate 21 - Boom Regenerative Valve 32 - Arm 1 Flow Rate Control
Control Valve (Poppet Valve (Switch Valve)
Valve)
11 - Bucket Flow Rate 22 - Boom Anti-Drift Valve (Switch 33 - Load Check Valve (Arm
Control Valve (Switch Valve) Regenerative Circuit)
Valve)
T3-3-13
COMPONENT OPERTATION / Control Valve
1 2 3 4 5 6 7 8 9 10 11
12
42
13
14
41
15
40
16
39
17
38
18
19
20
37
36
35 21
34
22
23
33
32 24
31 30 29 28 27 26 25
T1V1-03-03-021C
T3-3-14
COMPONENT OPERTATION / Control Valve
K K
L L
M M
T1V1-03-03-010
T1V1-03-03-027
Cross Section K-K
Cross Section L-L
8 6
N N
T1V1-03-03-028
T1V1-03-03-022
1- Load Check Valve (Left 12 - Bucket Regenerative Valve 23 - Arm 2 Flow Rate Control 34 - Arm Anti-Drift Valve
Travel Parallel Circuit) Valve (Switch Valve) (Switch Valve)
2 - Check Valve (Main 13 - Overload Relief Valve 24 - Load Check Valve (Arm 2 35 - Overload Relief Valve
Relief Circuit) (Bucket: Rod Side) Tandem Circuit) (Arm: Bottom Side)
3 - Main Relief Valve 14 - Overload Relief Valve 25 - Bypass Shut-Out Valve 36 - Arm Anti-Drift Valve (Check
(Bucket: Bottom Side) Valve)
4- Check Valve (Auxiliary 15 - Boom Flow Control Valve 26 - Arm 2 Flow Rate Control 37 - Overload Relief Valve
Combining Valve Circuit) (Poppet Valve) Valve (Poppet Valve) (Arm: Rod Side)
5 - Auxiliary Flow Combiner 16 - Boom Lower Meter-In Cut 27 - Arm Regenerative Valve 38 - Check Valve (Digging
Valve Valve Regenerative Circuit)
6 - Check Valve (Flow 17 - Boom Flow Control Valve 28 - Digging Generative Valve 39 - Load Check Valve (Boom 2
Combiner Valve Circuit) (Switch Valve) Parallel Circuit)
7 - Flow Combiner Valve 18 - Overload Relief Valve (Boom: 29 - Load Check Valve (Digging 40 - Auxiliary Flow Rate Control
Bottom Side) Regenerative Circuit) Valve (Poppet Valve)
8- Load Check Valve 19 - Boom Anti-Drift Valve (Check 30 - Arm 1 Flow Rate Control 41 - Auxiliary Flow Rate Control
(Orifice) (Bucket) Valve) Valve (Poppet Valve) Valve (Switch Valve)
9 - Check Valve (Main 20 - Overload Relief Valve (Boom: 31 - Load Check Valve (Swing 42 - Load Check Valve (Left
Relief Circuit) Rod Side) Circuit) Travel Tandem Circuit)
10 - Bucket Flow Rate 21 - Boom Regenerative Valve 32 - Arm 1 Flow Rate Control
Control Valve (Poppet Valve (Switch Valve)
Valve)
11 - Bucket Flow Rate 22 - Boom Anti-Drift Valve (Switch 33 - Load Check Valve (Arm
Control Valve (Switch Valve) Regenerative Circuit)
Valve)
T3-3-15
COMPONENT OPERTATION / Control Valve
Layout of Positioning Control Valve (2-Piece Boom)
4
3
T1V1-03-03-019C
T3-3-16
COMPONENT OPERTATION / Control Valve
3
T178-03-03-070C
X T198-03-03-003
1- Load Check Valve 2- Overload Relief Valve 3- Overload Relief Valve 4- Load Check Valve
(Positioning Tandem Circuit) (Positioning: Rod Side) (Positioning: Bottom Side) (Positioning Parallel Circuit)
T3-3-17
COMPONENT OPERTATION / Control Valve
HYDRAULIC CIRCUIT
Main Circuit
Pressure oils from pump 1 and pump 2 flow to the
4-spool section and 5-spool section of the control
valve respectively.
The parallel circuit is provided in both right and left
main circuits and makes the combined operation
possible. The flow combining circuit is provided in both
boom and arm circuits so that pressure oils from pump
1 and pump 2 are combined during a single operation.
T3-3-18
COMPONENT OPERTATION / Control Valve
Travel Motor
Travel Motor (Left) 4-Spool Section (Right)
5-Spool Main Relief
Valve Parallel Circuit
Section
4-Spool Section
Front
Attachment
Bucket
Cylinder
Overload
Relief Valve
Arm Cylinder
Overload
Relief Valve
Swing Motor Boom
Cylinder
Flow Combining
5-Spool Section Circuit
Parallel Circuit
Pump 2 Pump 1
T1V1-03-03-018
T3-3-19
COMPONENT OPERTATION / Control Valve
Positioning Circuit (2-Piece Boom)
T3-3-20
COMPONENT OPERTATION / Control Valve
Neutral
Circuit
Bypass
Shut-Out Valve
Positioning
Cylinder
Shuttle
Valve
Parallel
Circuit
Pump 1
Positioning Boom
Pilot Pressure Lower Pilot
Pressure
T1V1-03-03-020
T3-3-21
COMPONENT OPERTATION / Control Valve
Pilot Control Circuit External Pilot Pressure Circuit
Pressure oil (indicated with numbers) from the pilot • Pressure in the main relief valve is increased by
valve acts to the spool in control valve in order to move pilot pressure from solenoid valve (SG)
the spool. • The arm regenerative valve and arm 2 flow rate
In the following operations, pressure oil moves the control valve are shifted by pilot pressure from
spool and acts to the switch valves as follows. solenoid valve unit (SC).
• During arm roll-in (4) operation, pressure oil • The digging regenerative valve is shifted by pilot
moves the arm spool and shifts the spool in pressure from solenoid valve unit (SF).
switch valve of arm anti-drift valve. • The arm 1 flow rate control valve is shifted by pilot
• During boom lower (2) operation, pressure oil pressure from the arm flow rate control valve
moves the boom 1 spool and shifts the spool in spool in signal control valve.
switch valve of boom anti-drift valve. • The flow combiner valve is shifted by pilot
• During boom lower (2) operation, divided pressure from the flow combiner valve spool in
pressure oil passes through the boom lower signal control valve.
meter-in cut valve and shifts the bypass shut-out • The bucket flow rate control valve is shifted by
valve and boom 2 spool. pressure oil from the bucket flow rate control
• During auxiliary open (13) or close (14) operation, valve spool in signal control valve.
pressure oil moves the auxiliary spool and shifts • The auxiliary flow rate control valve is shifted by
the auxiliary flow combiner valve. pilot pressure from the auxiliary flow rate control
(Only the machine equipped with the optional solenoid valve (optional). (Only the machine
auxiliary flow combining system) equipped with the optional auxiliary flow
combining system)
The air bleed circuit is located on the upper section of
control valve and bleeds any air trapped inside NOTE: In general, the auxiliary flow combiner
automatically. valve and auxiliary flow rate control valve
are routed to the drain circuit.
T3-3-22
COMPONENT OPERTATION / Control Valve
Pilot Pressure
from Auxiliary Pilot Pressure
(Only machine from Solenoid
Auxiliary Flow equipped with Valve Unit
Combiner Valve optional (SG)
Main Relief
Valve auxiliary flow
combining
system) Flow Combiner Bucket Flow Rate
Valve Control Valve
T3-3-23
COMPONENT OPERTATION / Control Valve
Pilot Control Circuit (2-Piece Boom) External Pilot Pressure Circuit (2-Piece Boom)
Pressure oil (indicated with numbers) from the pilot • Pressure in the main relief valve is increased by
valve acts to the spool in control valve in order to move pilot pressure from solenoid valve (SG)
the spool. • The arm regenerative valve and arm 2 flow rate
In the following operations, pressure oil moves the control valve are shifted by pilot pressure from
spool and acts to the switch valves as follows. solenoid valve unit (SC).
• During arm roll-in (4) operation, pressure oil • The digging regenerative valve is shifted by pilot
moves the arm spool and shifts the switch valve in pressure from solenoid valve unit (SF).
arm anti-drift valve and the spool in hose rupture • The arm 1 flow rate control valve is shifted by pilot
valve (arm). pressure from the arm flow rate control valve
• During boom lower (2) operation, pressure oil spool in signal control valve.
moves the boom 1 spool and shifts the switch • The flow combiner valve is shifted by pilot
valve in boom anti-drift valve and the spool in pressure from the flow combiner valve spool in
hose rupture valve (boom). signal control valve.
• During boom lower (2) operation, divided • The bucket flow rate control valve is shifted by
pressure oil passes through the boom lower pressure oil from the bucket flow rate control
meter-in cut valve and shifts the bypass shut-out valve spool in signal control valve.
valve and boom 2 spool. • The auxiliary flow rate control valve is shifted by
• During auxiliary open (13) or close (14) operation, pilot pressure from the auxiliary flow rate control
pressure oil moves the auxiliary spool and shifts solenoid valve (optional). (Only the machine
the auxiliary flow combiner valve. equipped with the optional auxiliary flow
(Only the machine equipped with the optional combining system)
auxiliary flow combining system)
• During positioning operation, pressure oil moves NOTE: In general, the auxiliary flow combiner
the positioning spool and shifts the bypass valve and auxiliary flow rate control valve
shut-out valve. are routed to the drain circuit.
The auxiliary flow rate control solenoid
The air bleed circuit is located on the upper section of valve is installed to only the machine
control valve and bleeds any air trapped inside equipped with the optional auxiliary flow
automatically. combining system.
T3-3-24
COMPONENT OPERTATION / Control Valve
Pilot Pressure
from Auxiliary
(Only machine
Auxiliary Flow equipped with Pilot Pressure
Combiner Valve optional auxiliary from Solenoid Flow Combiner
flow combining Valve Unit Valve
Main Relief Valve (SG)
system) Bucket Flow Rate
Control Valve
T3-3-25
COMPONENT OPERTATION / Control Valve
FLOW COMBINER VALVE
1. During combined operation of front attachment
and travel, the flow combiner valve control spool
in signal control valve is shifted and pilot pressure
shifts the spool in flow combiner valve.
2. When the spool in flow combiner valve is shifted,
pressure oil from pump 1 flows to the spools in
left travel and bucket through the flow combiner
valve.
3. Therefore, pressure oil from pump 1 is routed to
both right travel and left travel spools.
4. Pressure oil from pump 2 is routed to the swing.
Consequently, during combined operation of
travel, front attachment and swing, the machine
can travel straight.
Pressure Oil
from Pump 1
Pilot Pressure
from Flow
Combiner Valve
Control Spool
T1V1-03-03-056
Spool
Hydraulic To Left Travel
Oil Tank Spool
T3-3-26
COMPONENT OPERTATION / Control Valve
Pilot Pressure
from Flow
Combiner Valve Travel Motor
Travel Motor (Left) Control Spool in (Right)
Flow Combiner Signal Control
Valve Valve
Bucket
Cylinder
Pump 1
T1V1-03-03-046
T3-3-27
COMPONENT OPERTATION / Control Valve
MAIN RELIEF VALVE
The main relief valve serves so that pressure in the
main circuit does not exceed the set pressure when
the actuator such as motor or cylinder is in operation.
Thus, oil leak from hose and pipe joints and breakage
of the actuator are prevented.
Relief Operation
1. Pressure in port HP (main circuit) acts to the pilot
poppet through orifice A in the main poppet and
orifice B in the seat.
2. When pressure in port HP reaches the set
pressure by spring B, the pilot poppet opens,
pressure oil from passage A flows along the
external circumference of sleeve and flows to port
LP (hydraulic oil tank).
3. At this time, a pressure difference is caused
between port HP and spring chamber due to
orifice A.
4. When this pressure difference reaches the set
pressure by spring A, the main poppet opens and
pressure oil from port HP flows to port LP.
5. As a result, the pressure in main circuit
decreases.
6. When pressure in the main circuit decreases to
the specified level, the main poppet is closed by
the force of spring A.
T3-3-28
COMPONENT OPERTATION / Control Valve
During Normal Operation:
Main Poppet Orifice A Orifice B Seat Passage Spring B
HP SG
LP
HP
LP
HP SG
LP
T3-3-29
COMPONENT OPERTATION / Control Valve
OVERLOAD RELIEF VALVE
(with Make-Up Function)
Passage A Valve
Pilot
Spring B Spring
Poppet
Chamber LP T198-03-03-006C
T3-3-30
COMPONENT OPERTATION / Control Valve
HP
LP
Orifice Piston Spring Pilot Spring C T107-02-05-019C
Chamber Poppet
During Relief Operation:
Main Poppet Sleeve Spring A Passage A Spring B
HP
LP
Orifice Piston T178-03-03-049C
Spring Pilot
Chamber Poppet
During Make-Up Operation:
Sleeve
HP
LP
T178-03-03-050C
Spring C
T3-3-31
COMPONENT OPERTATION / Control Valve
REGENERATIVE VALVE
The regenerative valves are provided in the boom
lower, arm roll-in and bucket roll-in circuits. The
regenerative valve increases cylinder speeds in order
to prevent cylinder hesitation, and improves machine
controllability.
Operation
1. When the bucket is rolled in, the return oil from
the cylinder rod side (bottom side of the boom Bucket
cylinder) enters hole in the spool and acts on the Cylinder
check valve.
2. At this time, if pressure in the cylinder bottom side
(rod side of the boom cylinder) is lower than the
rod side, the check valve is opened.
3. Then, return oil from the cylinder rod side flows
into the bottom side together with oil delivered Check Valve
from the pump and the cylinder speed increases.
4. When the cylinder is moved full stroke or the T176-03-03-027
T3-3-32
COMPONENT OPERTATION / Control Valve
Spool
Pressure Oil to
Cylinder Bottom
Side
Check
Valve
T1V1-03-03-057
T3-3-33
COMPONENT OPERTATION / Control Valve
ARM REGENERATIVE VALVE
Arm Regenerative
Valve
Chamber B
Hole
T3-3-34
COMPONENT OPERTATION / Control Valve
During Regenerative Operation:
Swing Motor
Pilot Pressure
from Solenoid
Valve Unit (SC)
Arm
Pump 2 Pump 1 Regenerative
Valve
T1V1-03-03-052
T3-3-35
COMPONENT OPERTATION / Control Valve
ANTI-DRIFT VALVE
The anti-drift valve is provided in the circuits of boom
cylinder bottom side and arm cylinder rod side and
prevents the cylinders from drifting.
Holding Operation
1. When the control lever is in neutral (neutral spool
position), the switch valve in anti-drift valve is not
shifted.
Boom Cylinder
2. Pressure at the boom cylinder bottom side (arm
cylinder rod side) passes through the switch valve
and acts to the check valve in anti-drift valve.
3. Consequently, as the check valve is pushed and
the return circuit from cylinder is blocked, the
cylinder drift is reduced.
Releasing Operation
1. When the arm is rolled in or the boom is lowered,
pressure oil from the pilot valve pushes the piston
in anti-drift valve and shifts the switch valve. T1V1-03-03-047
Anti-Drift Valve Anti-Drift Valve
2. Oil in the spring chamber of check valve flows (Switch Valve) (Check Valve)
back to the hydraulic oil tank through the passage
in switch valve.
3. When pressure in the spring chamber decreases
Pressure Oil To Hydraulic
and pressure oil from the cylinder bottom side is from Pump 1 Oil Tank
larger than pressure in the spring chamber and Boom Cylinder
spring force, the check valve moves to the right
due to a area difference.
4. Consequently, return oil from the boom cylinder
bottom side (arm cylinder rod side) flows to the
spool. From Pilot
As pressure decrease in the spring chamber is Valve
reduced by the orifice in switch valve, the check
valve is prevented from rapidly moving and the
shock is reduced during boom lower operation.
T1V1-03-03-048
Anti-Drift Valve Anti-Drift Valve
(Switch Valve) (Check Valve)
T3-3-36
COMPONENT OPERTATION / Control Valve
Holding Operation:
Switch Valve
Hydraulic Oil
Tank
To Main Spool
Releasing Operation:
Pressure Oil
from Pilot Valve Piston
To Main Spool
Spring
T3-3-37
COMPONENT OPERTATION / Control Valve
FLOW RATE CONTROL VALVE
The flow rate control valve is provided in boom, arm, Arm
bucket and auxiliary circuits, restricts oil flow rate in Cylinder
Switch
the circuit during combined operation and gives priority Valve
to other actuators.
Switch
Valve
Boom Cylinder
T1V1-03-03-076
T3-3-38
COMPONENT OPERTATION / Control Valve
Normal Operation (During Low Load)
Check Valve Poppet
To Arm 1 Spool
To Hydraulic
Oil Tank
Pressure Oil
Switch Valve from Pump 2
To Hydraulic
Oil Tank
To Arm 1 Spool
To Hydraulic
Oil Tank
Pressure Oil
Switch Valve from Pump 2
To Hydraulic
Oil Tank
To Arm 1 Spool
To Hydraulic
Oil Tank
To Arm 1 Spool
T1V1-03-03-064C
T3-3-39
COMPONENT OPERTATION / Control Valve
DIGGING REGENERATIVE VALVE
The digging regenerative valve is provided in the
return circuit of boom lower and functions during
combined operation of boom raise and arm roll-in.
When the digging regenerative valve is shifted,
pressure oil from the boom cylinder rod side (return
side) through the digging regenerative valve is
combined with pressure oil from pump 2 and flows to
the arm 1 spool. Therefore, speed of arm roll-in
increases.
(Refer to Section "Control System"/ SYSTEM.)
Operation
1. When solenoid valve unit (SF) is driven by the 4. Therefore, pressure oil from the boom cylinder
signal from main controller (MC), pressure oil rod side (return side) opens the check valve, is
from the pilot pump flows to port SF through combined with pressure oil from pump 2 and
solenoid valve unit (SF). flows to the arm 1 spool.
2. Pressure oil from port SF acts to the end of spool 5. Consequently, as oil flow rate to the arm cylinder
through the inner passage. increases, speed of arm roll-in increases.
3. The spool moves downward by compressing the
spring.
To Arm 1 Spool
Inner
Passage
Check Valve
SF
Spool Pilot Pressure
from Solenoid
Valve Unit (SF)
Return Oil
from Boom
Spring Cylinder Rod
Side
Digging
Regenerative T1V1-03-03-069
Valve
T3-3-40
COMPONENT OPERTATION / Control Valve
Spool
(Digging
Regenerative
Valve)
Boom 2
Spool
Boom Cylinder
Arm Cylinder
Pilot Pressure
from Solenoid
Valve Unit (SF)
Arm 1
Spool
Check
Valve
Pump 2
T1V1-03-03-053
T3-3-41
COMPONENT OPERTATION / Control Valve
BOOM LOWER METER-IN CUT VALVE
The boom lower meter-in cut valve is provided in the
boom lower circuit and functions with the boom flow
control valve together.
During boom lower operation with the front attachment
above the ground, the boom flow rate control valve
restricts pressure oil which flows to the boom 1 spool
from pump 1 and blocks pilot pressure to the arm 2
spool.
Therefore, during operation of boom lower and other
actuator, the boom falls due to own weight by the
regenerative circuit and uses pressure oil from the
pump for other actuator so that speed of other
actuator increases. (Refer to “Hydraulic System”/
SYSTEM.)
Operation (Jack-Up)
Operation (Boom Lower with Front Attachment 1. During jack-up operation, as pressure at the
above Ground) boom cylinder bottom side decreases, pressure in
1. During boom lower operation, pressure oil from the spring chamber decreases.
the pilot pump flows to the boom 2 spool from 2. When pressure in spring chamber becomes
port P19 through port P17 and boom lower lower than the spring force, the boom lower
meter-in cut valve. meter-in cut valve moves to the right due to the
2. Pressure oil (return oil) from the boom cylinder spring force.
bottom side flows to the spring chamber in boom 3. Therefore, as pressure oil which acts to the
lower meter-in cut valve through the orifice. switch valve in boom flow rate control valve from
3. When pressure in the spring chamber becomes port P17 flows to the hydraulic oil tank through
larger than the spring force, the boom lower the boom lower meter-in cut valve, the switch
meter-in cut valve compresses the spring moves valve is returned to the original position.
to the left. 4. Pressure oil from port P17 flows to the boom 2
4. Therefore, as port P19 is connected to the spool from port P 19 through the boom lower
hydraulic oil tank through the boom lower meter-in cut valve.
meter-in cut valve, the boom 2 spool is returned 5. Therefore, during jack-up operation, the boom
to the neutral position. lower meter-in cut control is not operated.
5. Pressure oil from port P17 flows to the switch (Refer to “Hydraulic System”/ SYSTEM.)
valve in boom flow rate control valve through the
spool.
6. The switch valve in boom flow rate control valve
is shifted and pressure oil which flows to the
boom 1 spool from pump 1 is reduced. (Refer to
“Flow Control Valve”.)
7. Consequently, during combined operation of
boom lower and other actuator, more pressure oil
is supplied to other actuator and speed of
actuator increases.
T3-3-42
COMPONENT OPERTATION / Control Valve
Boom Lower with Front Attachment above Ground Switch Valve (Boom Flow
Control Valve)
Boom Lower
Meter-In Cut
Valve
Boom 1 Spool
Boom 2 Spool
Port P17
Arm Cylinder
Port P19
Boom Cylinder
Pump 2 Pump 1
T1V1-03-03-051
Return Oil from
Boom Lower Boom Cylinder
Meter-In Cut Valve Bottom Side
Orifice
To
Hydraulic Spring
Oil Tank
PI7 PI9
To Switch To Boom 2 Spool
Valve Boom Lower
Pilot Pressure T1V1-03-03-074
T3-3-43
COMPONENT OPERTATION / Control Valve
AUXILIARY FLOW COMBINER VALVE AND
BYPASS SHUT-OUT VALVE Auxiliary Flow Combiner Valve
The auxiliary flow combiner valve and the bypass To Auxiliary Spool
shut-out valve are provided in the 5-spool section
circuit and the rear of 4-spool section circuit
respectively.
These valve functions differ depending on whether
only the front attachment is single-operated or SM
combined- operated. Front
Attachment
Pilot
Pressure
Check Valve
1. When the front attachment is single operated,
front attachemt pilot pressure acts to ports SM
and SJ and the spools in auxiliary flow combiner
valve and bypass shut-out valve are shifted.
2. When the spool in bypass shut-put valve is
shifted, the neutral circuit in 4-spool section is
blocked.
3. At this time, as the spool in auxiliary flow Spool
combiner valve is shifted, pressure oil in 4-spool
section (pump 1) flows to the auxiliary spool
through the auxiliary flow combining valve.
4. Consequently, pressure oil in pumps 1 and 2 is To Hydraulic Oil T1V1-03-03-066
combined so that operating speed of front Tank
attachment increases.
Bypass Shut-Out Valve
T1V1-03-03-068
To Hydraulic Spool
Oil Tank
T3-3-44
COMPONENT OPERTATION / Control Valve
SM
SN
Front
Attachment
Auxiliary
Neutral
Circuit
Bypass
Shut-Out Valve
SJ
Pump 2 Pump 1
T1V1-03-03-054
T3-3-45
COMPONENT OPERTATION / Control Valve
During Combined Operation Auxiliary Flow Combiner Valve
During combined operation of front attachment and
boom, arm, bucket or travel, do not shift the auxiliary To Auxiliary Spool
flow combiner valve. Therefore, operating speed of
boom, arm, bucket and travel is maintained.
SN
Front Attachment
or Travel Pilot
Pressure T1V1-03-03-065
T3-3-46
COMPONENT OPERTATION / Control Valve
SM
SN
Front
Attachment
Bucket Cylinder
Auxiliary
Bucket
Bypass
Shut-Out Valve
SJ
Pump 2 Pump 1
T1V1-03-03-055
T3-3-47
COMPONENT OPERTATION / Control Valve
(Blank)
T3-3-48
COMPONENT OPERATION / Pilot Valve
OUTLINE
The pilot valve controls pilot pressure oil in order to NOTE: As for the pilot valves for front attach-
move the spool in control valve. The pilot valve outputs ment/swing and for travel, the structure of
pressure according to the control lever stroke by PPC cam to push in the pusher is different and
(Pressure Proportional Control Valve) function and that of pressure-reducing valve is same.
moves the spool in control valve.
The 4-port pilot valves for front attachment/swing and
for travel are standard.
The 2-port pilot valve is for auxiliary (optional) and for
positioning (2-piece boom only).
Hydraulic P T P 4
Symbol
1 3 2 4 3 1
T105-02-07-020C
2 T1V1-03-04-001C
T
T3-4-1
COMPONENT OPERATION / Pilot Valve
• Travel Pilot Valve
Port No.
1 Travel (Right Reverse)
2 Travel (Right Forward)
3 Travel (Left Forward)
T
4 Travel (Left Reverse)
P
Hydraulic
Symbol
B T1M9-03-05-004C
View B 3 4
3 P T 4 2 1
T178-03-04-017C
2
1
T1M9-03-05-005C
T1CF-03-04-002C
1 2 T1CF-03-04-001C
1 2
T3-4-2
COMPONENT OPERATION / Pilot Valve
(Blank)
T3-4-3
COMPONENT OPERATION / Pilot Valve
OPERATION
T3-4-4
COMPONENT OPERATION / Pilot Valve
Front Attachment / Swing Pilot Valve
1 1
2 2
6
3 3 Port T
4 4
7
5 5 Port P
6 Output Port
6
Port T Port T
7 Port P 7 Port P
2 2 Port T
Port P
3 3 6
4 4
5 Output Port
5
6
Port T Port T
6
Port P Port P
7 7
T3-4-5
COMPONENT OPERATION / Pilot Valve
During Metering or Decompressing
(Output Curve: C to D)
1. When the control lever is further tilted in order to
move pusher (2) downward more, hole (7) on E F
spool (6) is opened to port P and pressure oil in
port P flows into the output port. D
2. Pressure in the output port acts on the bottom Pilot
surface of spool (6) so that spool (6) is pushed Pressure
upward.
3. Until upward force acting on the bottom surface of C
spool (6) overcomes the balance spring (4) force,
balance spring (4) is not compressed so that
spool (6) is not raised and pressure in the output A B
Lever Stroke
port increases. T523-02-05-001
4. As pressure in the output port increases, the force
to push spool (6) upward increases. When this
force overcomes the balance spring (4) force,
balance spring (4) is compressed so that spool (6)
is moved upward.
5. As spool (6) is moved upward, hole (7) is closed
so that pressure oil from port P stops flowing into
the output port and pressure in the output port
stops increasing.
6. As spool (6) is moved downward and balance
spring (4) is compressed, the pressure acting on
the bottom surface of spool (6) increases until the
pressure balances with the increasing spring
force. This increasing pressure becomes pres-
sure at the output port.
T3-4-6
COMPONENT OPERATION / Pilot Valve
Front Attachment / Swing Pilot Valve
1 1
2 2
3 3
4 4
5 5
6
6
Port T Port T
7 Port P 7 Port P
2 2
3 3
4 4
5 5
6 6
Port T Port T
7 Port P 7 Port P
T3-4-7
COMPONENT OPERATION / Pilot Valve
Full Stroke (Output Curve: E to F)
1. When the control lever is fully stroked, pusher (2)
is moved downward until pusher (2) on the front E F
attachment / swing pilot valve comes in contact
with the casing shoulder, or cam (1) on the travel D
pilot valve comes in contact with the casing. Pilot
2. At this time, the bottom surface of pusher (2) di- Pressure
rectly pushes spool (6). Therefore, even if pres-
sure in the output port increases further, hole (7) C
on spool (6) is kept open.
3. Consequently, pressure in the output port is equal
to that in port P. A B
Lever Stroke
T523-02-05-001
T3-4-8
COMPONENT OPERATION / Pilot Valve
2
2
4
5
E
Port T
7 Port P
2 E
6
Port T
Port P
7
T3-4-9
COMPONENT OPERATION / Pilot Valve
• Auxiliary / Positioning Pilot Valve
Pilot
Pressure
D
A B Pedal Stroke
T1F3-03-09-004
T3-4-10
COMPONENT OPERATION / Pilot Valve
In Neutral (Output Curve: A to B) During Metering or Decompressing (Output Curve: C
to D)
4
3
5 5
Port T Port T
6
(A)
Port P Port P
Hole Hole 7
Passage 7
Port T
(A)
Port P
T3-4-11
COMPONENT OPERATION / Pilot Valve
SHOCKLESS FUNCTION
(ONLY FOR TRAVEL PILOT VALVE) Damper Spring Pin Travel Pedal
Operation Gear 2
1. If the travel lever is released from the hand during A
traveling, spring force of the return spring returns Gear 1
the travel lever to the neutral position.
2. At this time, gears 1 and 2 inside the damper re-
ceive opposing force due to friction.
3. Therefore, as the travel lever gradually returns to
the neutral position, the extent of sudden stop at
the time of abrupt release of the travel lever is
damped down.
T1M7-03-04-002C
Section A-A
Spring Pin
Damper
Support
Pin
T1M7-03-04-003C
T3-4-12
COMPONENT OPERATION / Travel Device
OUTLINE
The travel device consists of the travel motor, travel The travel reduction gear is a three stage reduction
reduction gear and travel brake valve. The travel motor planetary gear type, converts rotary power transmitted
is a swash plate type variable displacement axial from the travel motor to slow large torque and rotates
plunger motor and equipped with the parking brake the sprocket and track. The travel brake valve protects
(wet-type negative multi-disc brake). The travel motor the travel circuit from being overloaded and prevents
is driven by pressure oil from the pump and transmits the occurrence of cavitation.
its rotary power to the travel reduction gear.
NOTE: The structure and theory of operation of the
travel device for ZX200-3 class and ZX240-
3 class can be thought as identical. Only
some parts differs. This section describes
the operation of ZX200-3 class and ZX270-
3 class.
Sprocket
Sprocket
T1V1-03-05-001C
Travel Motor W1HH-03-02-003C
Travel Motor
T3-5-1
COMPONENT OPERATION / Travel Device
TRAVEL REDUCTION GEAR
The travel reduction gear is a three-stage reduction Housing (14) in the travel motor is bolted to the track
planetary gear type. frame and is secured to drum (13) via bearing (15) by
The travel motor rotates propeller shaft (7). This rota- bearing nut (11). Housing (14) is also splined to third
tion is transmitted to ring gear (1) via first stage plane- stage carrier (2). Ring gear (1) is bolted to drum (13)
tary gear (8), first stage carrier (6), second stage sun and sprocket (12). Accordingly, when ring gear (1) is
gear (5), third stage planetary gear (9), second stage rotated, drum (13) and sprocket (12) are also rotated.
carrier (4), second stage sun gear (3), third stage
planetary gear (10).
15 1 2 3 4 5 6
14 13 11 10 9 8
12
T178-03-05-001C
1 - Ring Gear 5 - First Stage Sun Gear 9 - Second Stage Planetary 13 - Drum
Gear
2 - Third Stage Carrier 6 - First Stage Carrier 10 - Third Stage Planetary Gear 14 - Housing
3 - Second Stage Sun Gear 7 - Propeller Shaft 11 - Bearing Nut 15 - Bearing
4 - Second Stage Carrier 8 - First Stage Planetary Gear 12 - Sprocket
T3-5-2
COMPONENT OPERATION / Travel Device
ZX270-3 class
15 1 2 3 4 5 6
Travel Motor
14 13 11 10 9
W1HH-03-02-003C
12
1- Ring Gear 5 - Second Stage Sun Gear 9- Second Stage Planetary 13 - Drum
Gear
2- Third Stage Carrier 6 - First Stage Carrier 10 - Third Stage Planetary 14 - Housing
Gear
3- Third Stage Sun Gear 7 - Propeller Shaft 11 - Bearing Nut 15 - Bearing
4- Second Stage Carrier 8 - First Stage Planetary Gear 12 - Sprocket
T3-5-3
COMPONENT OPERATION / Travel Device
TRAVEL MOTOR
The travel motor is a variable-displacement swash The shoes on top of plungers slide along the swash
plate axial plunger motor and consists of valve plate, plate surface due to inclination of the swash plate and
swash plate, rotor, plungers and shaft. The shaft is the rotor rotates.
splined to the rotor, in which the plungers are inserted.
When pressure oil is supplied from the pump, the
plungers are pushed.
Swash
Shaft Rotor Shoe Plate
T3-5-4
COMPONENT OPERATION / Travel Device
ZX270-3 class
T3-5-5
COMPONENT OPERATION / Travel Device
PARKING BRAKE
The parking brake is a wet-type multi disc brake. The
brake is a negative type so that it is released only
when the brake release pressure oil is routed into the
brake piston chamber. The parking brake is automati-
cally applied unless the travel function is operated.
The friction plates and plates are splined to the hous-
ing in travel motor and rotor respectively.
T3-5-6
COMPONENT OPERATION / Travel Device
To Brake
BM Piston AM
Counterbalance
Valve Spool
T1V1-03-05-004
T3-5-7
COMPONENT OPERATION / Travel Device
TRAVEL MODE CHANGE
The tilt angle of swash plate (7) is changed by piston
(8) movement in order to select the travel mode.
T3-5-8
COMPONENT OPERATION / Travel Device
Motor Port
(AM, BM)
To
Drain
5 6 7 8
T178-03-05-010
T3-5-9
COMPONENT OPERATION / Travel Device
T3-5-10
COMPONENT OPERATION / Travel Device
Motor Port
1 (AM, BM)
5 6 7 8
T178-03-05-011
T3-5-11
COMPONENT OPERATION / Travel Device
TRAVEL BRAKE VALVE
The travel brake valve is located on the travel motor
head and consists of the following valves.
• Counterbalance Valve:
Makes starting and stopping travel operations
smooth and prevents the machine from running
away while descending slopes. Routes the travel
motor operating pressure oil in high pressure port
(AV or BV) to the parking brake.
• Check Valve:
Assists the counterbalance valve operation and pre-
vents cavitation in the motor circuit.
• Shuttle Valve:
Routes the travel motor operating high pressure oil
in high pressure port (AM or BM) to the slow or fast
side piston so that the piston is controlled.
• Orifice:
Makes the travel mode change (swash plate angle
control) smooth.
T3-5-12
COMPONENT OPERATION / Travel Device
T1V1-03-05-003C
A
Overload Relief Travel Motor Orifice
Valve Swash Angle Con-
trol Valve
T3-5-13
COMPONENT OPERATION / Travel Device
While Traveling: While Descending:
1. When pressure oil from the control valve flows to 1. While descending a slope, the travel motor is
port BV (8), pressure oil flows around the outer forcibly rotated by the machine weight so that the
diameter of spool (9), unseats check valve BC (7) motor operates like a pump.
and flows further to motor port BM (6). 2. If the travel motor draws oil, oil pressure in port
2. On the other hand, return oil from the travel motor BV (8) and chamber B (10) decrease, spool (9)
is routed to motor port AM (4). However, its pas- moves to the left so that return oil from the travel
sage is blocked by check valve AC (3) and spool motor is restricted.
(9). 3. Therefore, pressure in motor port AM (4) in-
3. When pressure in port BV (8) increases further, creases and brakes the travel motor.
pressure oil is routed into chamber B (10) through 4. Once pressure oil is restricted, pressure in motor
orifice (f) in spool (9) and moves spool (9) to the port BV (8) increases again and moves spool (9)
right. to the right. As this operation (hydraulic braking
4. Consequently, return oil from the travel motor operation) is repeated, the machine is prevented
flows to port AV (1) through notch (h) on spool (9). from running away.
Then, pressure oil is allowed to flow so that the
travel motor starts rotating. Circuit Protection Operation:
5. When the travel lever is returned to neutral, spool 1. When pressure in the circuit increases over the
(9) is returned to the original position by spring set-pressure of overload relief valve (5), overload
force and blocks the oil passage so that the travel relief valve (5) is opened and high-pressure oil re-
motor rotation is stopped. lieves to the low pressure side so that the travel
motor is protected from being overloaded.
2. In addition, overload relief valve (5) relieves the
shock loads developed due to inertia force when
stopping the travel motor.
3. If the travel motor draws oil like a pump, check
valve BC (7) is unseated (make-up operation) so
that cavitation is prevented.
T3-5-14
COMPONENT OPERATION / Travel Device
10 8 9 1 2
BV AV
6
4
7
3
T178-03-05-006C
T3-5-15
COMPONENT OPERATION / Travel Device
(Blank)
T3-5-16
COMPONENT OPERATION / Signal Control Valve
OUTLINE
The signal control valve is provided in the pilot circuit
between the pilot valve and control valve, and controls
pilot signal pressure to regulate the pumps and
various kinds of valves.
The major components of signal control valve are
shuttle valve, shockless valve, pump 1 flow rate
control valve, pump 2 flow rate control valve, flow
combiner valve spool, bucket flow rate control valve
spool, swing parking brake release spool and arm 1
flow rate control valve spool.
T178-03-06-016CC
Shockless Valve
Arm 1 Flow Rate Control Valve Bucket Flow Rate Control Valve Spool
spool
Pump 1 Flow Rate Control Valve Pump 2 Flow Rate Control Valve
T178-03-06-002C
T3-6-1
COMPONENT OPERATION / Signal Control Valve
PILOT PORT
T3-6-2
COMPONENT OPERATION / Signal Control Valve
E
M
D
H
B
F
SB
PI G
K N
I
SH
J
DF
SA L
T178-03-06-016CC
1 5
13
2 4
SK
SE
8
Pressure Sensor (Swing)
14
Control Valve Side
7
9
6
10
SN
SL
11
T3-6-3
COMPONENT OPERATION / Signal Control Valve
Machine with Front Attachment (Secondary Crushers 1 to 5 and Hydraulic Crushers 1 to 5) attached.
Port SM Auxiliary Flow Rate Combiner Solenoid Valve Auxiliary Flow Rate Combiner Valve Control
Pressure
Port SN Auxiliary Flow Rate Combiner Control Valve Auxiliary Flow Rate Combiner Valve Control
Pressure
Port SP Auxiliary Flow Rate Combiner Solenoid Valve Pump 1 Control Pressure
T3-6-4
COMPONENT OPERATION / Signal Control Valve
Pilot Valve Side
PH
C
A
E
M
D
H
B
F
SB
PI G
K N
I
SH
J
DF
SA L
T178-03-06-016CC
1 5
13
2 4
SK
SE
8
Pressure Sensor (Swing)
14
Control Valve Side
7
9
6
10
SN
SL
11
T3-6-5
COMPONENT OPERATION / Signal Control Valve
SHUTTLE VALVE
The shuttle valve selects pilot pressure oil to perform
each operation and routes pilot pressure to the
corresponding flow rate control valves and/or switch
valve spools. The flow rate control valves and/or
switch valve spools corresponding to each operation
are as follows:
Pump 1 Flow Pump 2 Flow Flow Bucket Flow Swing Arm Flow
Rate Control Rate Control Combiner Rate Control Parking Rate
Valve Valve Valve Control Valve Control Brake Control
Spool Spool Release Valve
Spool Control
Spool
Boom Raise { { - - { -
Boom Lower { - - - { -
Arm Roll- Out { { - - { -
Arm Roll- In { { - { { {
Bucket Roll-In { - - - { -
Bucket Roll-Out { - - - { -
Right Swing - { - - { -
Left Swing - { - - { -
Right Travel { - { - - -
Left Travel - { - - - -
Auxiliary *{ { - - { -
Positioning
(2-Piece Boom { - - - - -
Only)
T3-6-6
COMPONENT OPERTATION / Signal Control Valve
Monoblock Boom / STD Specification
5 6 7 8 9
Left Travel Right Travel Swing Arm Boom Bucket 10
1 2 3 4 11
12
13
14 15 16 17
Arm 1 Flow
Rate Control
Valve Spool
1- Left Travel 6- Boom / Arm / Bucket / Right 11 - Boom / Arm / Bucket 16 - Swing / Auxiliary
Travel / Auxiliary /
Positioning
2- Left Travel/Right Travel 7 - Boom / Arm 12 - Boom / Arm / Bucket / Swing 17 - Auxiliary
/ Auxiliary
3- Right Travel 8- Boom 13 - Arm / Boom Raise / Swing /
Auxiliary
4- Boom / Arm / Bucket / 9- Arm / Boom Raise 14 - Bucket
Right Travel
5 - Arm 10 - Boom Raise / Arm / Left 15 - Swing
Travel / Swing
T3-6-7
COMPONENT OPERTATION / Signal Control Valve
Machine with Monoblock Boom and Auxiliary Flow Combining Attached (Optional)
6
Auxiliary
Auxiliary Flow
Rate Combiner
Solenoid Valve
Pump 1 Flow Rate
Control Valve
T1V1-03-06-007C
Shuttle
Valve
Auxiliary Flow
Rate Combiner
Solenoid Valve
Shuttle Valve
T1V1-03-06-006C
T3-6-8
COMPONENT OPERTATION / Signal Control Valve
T178-03-06-016CC
5
8
7
16
17
15
13
11
14
6 10
12
3
1
4
2
T178-03-06-009C
1 - Left Travel 6- Boom / Arm / Bucket / Right 11 - Boom / Arm / Bucket 16 - Swing / Auxiliary
Travel / Auxiliary / Positioning
2 - Left Travel/Right Travel 7 - Boom / Arm 12 - Boom / Arm / Bucket / Swing / 17 - Auxiliary
Auxiliary
3 - Right Travel 8- Boom 13 - Arm / Boom Raise / Swing /
Auxiliary
4 - Boom / Arm / Bucket / Right 9- Arm / Boom Raise 14 - Bucket
Travel
5 - Arm 10 - Boom Raise / Arm / Left 15 - Swing
Travel / Swing
T3-6-9
COMPONENT OPERTATION / Signal Control Valve
SHOCKLESS VALVE
The shockless valve is provided in the boom raise
Port A
circuit and functions during boom lowering operation. Spool Spring B
Port 1 T1V1-03-06-002C
T3-6-10
COMPONENT OPERTATION / Signal Control Valve
During Boom Raising Operation
Inner Passage 2
Spring B
Port 1 T183-03-06-003C
Spool Port A
Port 1 T183-03-06-004C
Detail of Housing
Clearance C
Spool T1V1-03-06-008C
T3-6-11
COMPONENT OPERTATION / Signal Control Valve
During Boom Lowering Operation (Shock
Reducing Operation)
1. When the boom is lowered, the return oil from the
Port A
boom raise spool in the control valve is routed to Spring A Spool Spring B
port 1.
2. As the spool blocks the oil passage between port
1 and port A, return oil cannot flow directly to port
A.
3. Port 1 is connected to the spring A side in spool
via inner passage 1 and to the oil chamber via
inner passage 2.
4. Pressure oil in the oil chamber flows from
clearance C between spool and housing and
pressure in the oil chamber decreases. The spool Port 1
T1V1-03-06-004C
is moved to the right by pressure acting on the
spring A side. Thereby, clearance C between the
spool and housing is closed and pressure oil is
blocked.
5. When clearance C is closed, pressure in the oil Port A
Spring A Spool Spring B
chamber increases and the spool moves to the
left. Therefore, clearance C is opened again and
pressure oil flows to port A.
6. As operations in steps (4 and 5) are repeated,
pressure oil is gradually returned to port A so that
the control spool returns slowly.
Port 1 T1V1-03-06-002C
T3-6-12
COMPONENT OPERTATION / Signal Control Valve
During Boom Lowering Operation (Shockless
Operation)
T183-03-06-005C
Spool
Port A
T183-03-06-004C
Spool T1V1-03-06-008C
T3-6-13
COMPONENT OPERTATION / Signal Control Valve
PUMP 1 AND PUMP 2 FLOW RATE
CONTROL VALVES
The pump flow rate control valve delivers pump
control pressure Pi to the pump regulator in response
to pilot pressure from the pilot valve.
T3-6-14
COMPONENT OPERTATION / Signal Control Valve
Ports SA, SB
Spool
Spring
To Hydraulic
Oil Tank
Chamber A
Shuttle Valve
Primary Pilot
Pressure
Pilot Pressure
T1V1-03-06-005C
T3-6-15
COMPONENT OPERTATION / Signal Control Valve
BUCKET FLOW RATE CONTROL VALVE
CONTROL SPOOL, FLOW COMBINER
VALVE CONTROL SPOOL, SWING
PARKING BRAKE RELEASE SPOOL, ARM
1 FLOW RATE CONTROL VALVE Bucket Flow Rate Control Valve Control Spool:
CONTROL SPOOL To Hydraulic Boom Raise Control
Oil Tank Pilot Pressure
Spool Spring
NOTE: The spools above are identical in
operational principle.
T178-03-06-014C
Boom, Arm, To Swing
Bucket or Motor
Auxiliary Pilot
Pressure
T178-03-06-014C
Arm Roll-in Arm 1 Flow
Control Pilot Rate Control
Pressure Valve
T3-6-16
COMPONENT OPERATION / Others (Upperstructure)
PILOT SHUT-OFF SOLENOID VALVE
Cross
The pilot shut-off solenoid valve is a solenoid Section Z-Z
valve-operated switch valve.
The spool in pilot shut-off solenoid valve is shifted by
the pilot shut-off lever and turns on or off pilot To Ports T1
to T4
pressure oil to the pilot valve and signal control valve.
From Pilot
Pump
To Ports A1
to A4
Spool
T1V1-03-07-012C
A1
P T1
T2
A2
A3
Z
T3
T4
A4
T1V1-03-07-011C
A1 - Travel / Auxiliary Pilot A4 - Signal Control Valve (Port T1 - Travel / Auxiliary Pilot T3 - Left Pilot Valve
Valve PI) Valve
A2 - Right / Positioning Pilot P - Primary Pilot Pressure T2 - Right / Positioning Pilot T4 - Hydraulic Oil Tank
Valve Valve
A3 - Left Pilot Valve
T3-7-1
COMPONENT OPERATION / Others (Upperstructure)
• Pilot Shut-Off Lever: LOCK Position
1. When the pilot shut-off lever is in the LOCK
position, the pilot shut-off relay is turned OFF and
the pilot shut-off solenoid valve is turned OFF.
(Refer to Electrical System/ SYSTEM.)
2. Pressure oil from the pilot pump is blocked by the
spool in pilot shut-off solenoid valve.
3. Oil to the pilot valve and signal control valve sides
flow to the hydraulic oil tank.
4. Therefore, although the control/travel lever is
operated, the pilot valve is not operated.
Spool
T1V1-03-07-012C
T3-7-2
COMPONENT OPERATION / Others (Upperstructure)
SOLENOID VALVE
The solenoid valve consists of the solenoid valve unit
for pump and valve 4-spool control and the 2-spool
solenoid valve unit (optional) for auxiliary flow rate
control.
control valve
T1GL-03-10-002C
T3-7-3
COMPONENT OPERATION / Others (Upperstructure)
Proportional Solenoid Valve
1 2 3
T S P
a
T107-02-07-005C
T3-7-4
COMPONENT OPERATION / Others (Upperstructure)
ON / OFF Solenoid Valve
• In Neutral State
Spool (1) is pushed to the right by spring (2).
Output port (S) is connected to tank port (T).
• In Operation
As solenoid (3) is activated, spool (1) moves to the left.
Pilot port (P) is connected to output port (S) and tank
port (T) is blocked.
P S T
1 2 T105-02-11-010C
T3-7-5
COMPONENT OPERATION / Others (Upperstructure)
HOSE RUPTURE VALVE
The hose rupture valve is installed to boom cylinder
(bottom side circuit), arm cylinder (rod side circuit) and
positioning cylinder (2-piece boom) (rod side circuit).
When the hose of front attachment is damaged, the
hose rupture valve holds the front attachment and
prevents the front attachment from falling.
2- Spool 8 - Passage B
4- Passage A 9 - Passage C
5- Spring 10 - Spring
6- Poppet
T3-7-6
COMPONENT OPERATION / Others (Upperstructure)
10 11 1 2 3
Port Pi
9 5
8 Port B
Port A
T1V1-03-07-017C
T3-7-7
COMPONENT OPERATION / Others (Upperstructure)
• During Boom Lowering Operation (Control Lever
Stroke: Less then Half-Stroke) 5 9 4
1. When the boom is lowered, pilot pressure Pi acts
on piston (3). 7
2. When the boom lower control lever is less than
half-stroke, piston (3) restricts spool (2) and
pushes spool (2) to the position where orifice (11)
is opened.
6
3. Pressure oil in the spring (5) chamber is blocked
by spool (2) and poppet (6) is pushed downward.
4. Pressure oil from port B flows to the spool in Pressure
control valve through passage C (9), orifice (11) Pi
and passage B (8) and lowers the boom.
Port B
5. As oil flow rate through the spool in control valve
is reduced by orifice (11), the boom is lowered
slowly. 10 8 2 3
Port A
2- Spool 7- Orifice
3- Piston 8- Passage B
4- Passage A 9- Passage C
5- Spring 10 - Spring
6- Poppet
T3-7-8
COMPONENT OPERATION / Others (Upperstructure)
10 11 1 2 3
Pressure Pi
9 5
8 Port B
Port A
T1V1-03-07-015C
T3-7-9
COMPONENT OPERATION / Others (Upperstructure)
• During Boom Lowering Operation (Control Lever
Stroke: More than Half-Stroke) 5 9 4
1. When the boom lower control lever is more than
half-stroke, piston (3) pushes spool (2) to the 7
position where passage (4) is connected to the
hole on spool (2).
2. Therefore, pressure oil in the spring (5) chamber
flows to passage B through spool (2) from the
6
hole on spool (2).
3. Pressure in passage C (9) flows to passage B (8)
through orifice (11). Pressure
4. At this time, a pressure difference between port B Pi
and the spring (5) chamber appears due to orifice
Port B
(7) and poppet (6) moves upward.
5. Consequently, return oil from port B flows to the
spool in control valve through poppet (6) from 10 8 2 3
Port A
port A and lowers the boom.
6. As pressure oil in port B flows to port A directly, oil
flow rate through the spool in control valve
increases and boom lowering speed becomes To Spool in Control
T1V1-03-07-020C
fast. Valve
2- Spool 7- Orifice
3- Piston 8- Passage B
4- Passage A 9- Passage C
5- Spring 10 - Spring
6- Poppet
T3-7-10
COMPONENT OPERATION / Others (Upperstructure)
10 11 1 2 3
Pressure Pi
9 5
8 Port B
Port A
T1V1-03-07-016C
T3-7-11
COMPONENT OPERATION / Others (Upperstructure)
PILOT RELIEF VALVE
Pilot Relief
Valve
The pilot relief valve has a pilot filter incorporated.
Port P
The pilot relief valve functions to regulate pilot pump
pressure oil routed to port P to a set constant
pressure.
Pilot Filter
T178-03-07-001C
T3-7-12
COMPONENT OPERATION / Others (Undercarriage)
SWING BEARING
The swing bearing sustains self weight of the upper
structure and makes smooth swing.
This bearing is a single row type ball bearing and con-
sists of outer race (1), inner race (3), ball (6), support
(5) and seals (2, 4).
Outer race (1) is bolted to the upper structure and in-
ner race (3) is bolted to the undercarriage. The inter-
nal teeth of inner race (3) are enmeshed with output
shaft of swing reduction gear.
T135-03-02-001C
T3-8-1
COMPONENT OPERATION / Others (Undercarriage)
CENTER JOINT
The center joint is a 360° rotating joint. When the Hydraulic oil flows to the right and left travel motors
upperstructure is rotated, the center joint avoids via spindle (1) and the oil ports of body (2). Seals (3)
twisting of hoses and allows hydraulic oil to flow prevent oil leaks between spindle (1) and body (2)
smoothly to or from the travel motors. Spindle (1) is into adjacent passages.
attached to the main frame, and body (2) is bolted to
the swing center of the undercarriage.
1
Pilot Pressure Pilot Pressure
for Travel Speed Selection Drain for Travel Speed
Selection
Drain
Drain 3
Drain
: Forward
: Reverse
: Pilot Pressure
for Travel Speed Selection
T157-03-02-004C
T3-8-2
COMPONENT OPERATION / Others (Undercarriage)
TRACK ADJUSTER
CAUTION: Do not loosen valve (12) quickly
The track adjuster located on the side frame is
or loosen too much as high-pressure
composed of spring (7) and adjuster cylinder (5).
grease in adjusting cylinder (5) may spout
Spring (7) absorbs loads applied to the front idler.
out.
Adjuster cylinder (5) adjusts track sag.
Loosen valve (12) carefully while keeping
body parts and face away from valve (12).
• Grease is applied through grease fitting into
Do not loosen the grease fitting.
chamber A of adjuster cylinder (5), pushes piston
rod (2) out and decreases track sag.
Grease Fitting 12
• Loosen valve (12) 1 to 1.5 turns counterclockwise
and release grease in order to increase track sag.
Grease Discharge
Hole W8HY-04-03-001
2 5 A 7 6 11 12
1 3 4 8 9 10
W1V7-03-04-002
T3-8-3
COMPONENT OPERATION / Others (Undercarriage)
(Blank)
T3-8-4