JP6872508B2 - Construction machinery - Google Patents

Description

The present invention relates to a construction machine such as a hydraulic excavator, and more particularly to a construction machine provided with a soil removal device.

Generally, a hydraulic excavator, which is a typical example of a construction machine, is provided on a self-propelled lower traveling body, an upper rotating body mounted on the lower traveling body so as to be swivel via a swivel device, and a front side of the upper swivel body. It is configured with the work equipment provided. Further, in a small hydraulic excavator, a soil removal device is provided on a truck frame constituting a lower traveling body, and soil removal work such as earth and sand is performed using this soil removal device.

Here, the earth removal device of the hydraulic excavator consists of an elevating arm whose base end side is swingably attached to the track frame in the upward and downward directions, and a rectangular plate-like body extending in the left and right directions, and the tip of the elevating arm. A blade mounted on the blade, a blade elevating cylinder that swings the lifting arm upward and downward, a tilt cylinder that swings both ends in the blade length direction (left and right) upward and downward, and a blade. It is composed of an angle cylinder that swings both ends in the length direction forward and backward.

On the other hand, the upper swivel body includes a swivel frame, a prime mover provided on the swivel frame to drive a hydraulic pump, and a driver's seat provided on the swivel frame on which an operator is seated. Left and right operation lever devices for operating the work device and the swivel device are provided on both the left and right sides of the driver's seat, and a blade operation device for operating the blade of the earth removal device is provided in the vicinity of the operation lever device. It is provided.

Here, the blade operating device according to the prior art has an operating lever operated by an operator, and by tilting the operating lever in the forward and backward directions, the raising and lowering operation of the blade is controlled and tilted in the left and right directions. This controls the tilting operation of the blade. Further, the angle movement of the blade is controlled by rotating the operation lever around the center of the shaft (see Patent Document 1).

Further, in other conventional blade operation devices, a grip is attached to the tip of an operation lever, and a seesaw type switch is provided on the top of the grip. Then, the raising and lowering operation of the blade is controlled by tilting the operation lever in the forward and backward directions, and the tilting operation of the blade is controlled by operating the seesaw type switch. Further, the angle movement of the blade is controlled by rotating the grip on the tip side of the operating lever (see Patent Document 2).

Japanese Unexamined Patent Publication No. 2001-262625 Japanese Unexamined Patent Publication No. 2015-21336

In a small hydraulic excavator equipped with a soil removal device, it is difficult to secure sufficient space for arranging the left and right operation lever devices and blade operation devices around the driver's seat. In particular, when the driver's seat is arranged in the cab mounted on the swivel frame, the space between the side surface (window) of the cab and the driver's seat becomes very narrow, and the operation lever device is contained in this narrow space. And the blade operating device will be arranged.

Therefore, in the blade operating device according to Patent Document 1, when the operating lever is tilted to the left or right in order to control the tilting operation of the blade, the operator's hand comes into contact with the side surface of the cab or the operating lever device. There is. Further, also in the blade operating device according to Patent Document 2, when the grip is rotated on the tip side of the operating lever in order to control the angle movement of the blade, the operator's hand may come into contact with the side surface of the cab or the operating lever device. is there. Therefore, the space for operating the blade operating device is limited, and not only the operability of the blade operating device is impaired, but also the operating lever device may be erroneously operated when operating the blade operating device.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a construction machine capable of smoothly operating a blade operating device even when the space around the driver's seat is narrow. It is said.

In order to solve the above-mentioned problems, the present invention is provided on a self-propelled lower traveling body, an upper rotating body mounted on the lower traveling body so as to be swivelable via a swivel device, and the upper swivel body. The upper swivel body is composed of a working device and a soil discharging device provided on the lower traveling body, and the upper swivel body is provided on the swivel frame, a prime mover provided on the swivel frame to drive a hydraulic pump, and the swivel frame. A driver's seat and a blade operating device provided on the side of the driver's seat to operate the blades of the soil discharging device are provided, and the soil discharging device is provided on the lower traveling body so as to be swingable upward and downward. The lifting arm, the blade attached to the tip of the lifting arm, the blade lifting cylinder that swings the lifting arm upward and downward, and both ends of the blade in the longitudinal direction in the front and rear directions. It is applied to a construction machine composed of an angle cylinder that swings and a tilt cylinder that swings both ends in the length direction of the blade upward and downward.

A feature of the present invention is that the blade operating device operates a blade operating lever that operates the blade elevating cylinder by tilting it in the forward and backward directions, and operates the angle cylinder or the tilt cylinder provided on the blade operating lever. A tilt angle operation switch and a cylinder selection switch provided on the blade operation lever to select a cylinder operated by the tilt angle operation switch among the angle cylinder and the tilt cylinder are provided , and the blade operation lever grips. The tilt / angle operation switch is arranged on the upper surface portion of the grip, and the cylinder selection switch is arranged on the back surface portion of the grip .

According to the present invention, the blade elevating cylinder can be operated by tilting the blade operating lever forward and backward, and by operating the tilt angle operating switch and the cylinder selection switch provided on the grip. The tilt cylinder and the angle cylinder can be operated. Therefore, it is not necessary to tilt the blade operating lever in any direction other than the forward and backward directions, and to rotate the grip. Therefore, even when the blade operating device is arranged in a narrow space formed around the driver's seat, the blade operating device can be smoothly operated.

It is a front view which shows the hydraulic excavator by embodiment of this invention. It is a top view of the hydraulic excavator with the work device removed. It is a top view which shows the driver's seat, the operation lever device, the blade operation device, etc. in a cab partially broken. It is a perspective view which shows the blade operation apparatus. It is an enlarged view of the main part which shows the grip of the blade operation device, the tilt angle operation switch, the cylinder selection switch and the like. It is a hydraulic circuit diagram which includes a blade elevating cylinder, an angle cylinder, a tilt cylinder, and a blade operation device.

Hereinafter, embodiments of the construction machine according to the present invention will be described in detail with reference to FIGS. 1 to 6 by taking a rear small turning type hydraulic excavator as an example.

The hydraulic excavator 1, which is a typical example of a construction machine, includes a crawler-type lower traveling body 2 capable of self-propelling, and an upper rotating body 4 mounted on the lower traveling body 2 so as to be swivelable via a swivel device 3. ing. A swing-type work device 5 for excavating earth and sand is provided on the front side of the upper swivel body 4.

Here, the lower traveling body 2 includes a track frame 2A as a base, and the track frame 2A is a pair of left and right side frames 2B extending in the front and rear directions (only the left side is shown). have. A floating wheel 2C is provided on one side in the front and rear directions of the left and right side frames 2B, and a driving wheel 2D is provided on the other side in the front and rear directions. The track 2E is wound around the idle wheel 2C and the drive wheel 2D, and the lower traveling body 2 travels by driving the track 2E by the drive wheel 2D. Further, the track frame 2A of the lower traveling body 2 is provided with a soil removal device 16 described later.

The work device 5 is attached to a swing post 5A that is swingably attached to the front end of a swivel frame 6 to be described later in the left and right directions, a boom 5B that is swingably attached to the swing post 5A so as to be able to move up and down, and a tip of the boom 5B. It includes an arm 5C rotatably attached, a bucket 5D rotatably attached to the tip of the arm 5C, a boom cylinder 5E, an arm cylinder 5F, and a bucket cylinder 5G. Further, a swing cylinder (not shown) for swinging the swing post 5A to the left and right is provided between the swing frame 6 and the swing post 5A.

The upper swivel body 4 includes a swivel frame 6, a counterweight 7, an engine 8, a cab 9, a driver's seat 10, left and right operating lever devices 12, 14 and a blade operating device 17, which will be described later.

The swivel frame 6 is a base of the upper swivel body 4, and is mounted on the lower traveling body 2 via the swivel device 3. A support bracket 6A projecting forward is provided on the front side of the swivel frame 6, and the swing post 5A of the working device 5 is supported by the support bracket 6A so as to be swingable in the left and right directions. A counterweight 7 is provided on the rear side of the swivel frame 6, and the counterweight 7 maintains a weight balance with the working device 5. The counterweight 7 is formed as an arc-shaped heavy object whose central portions in the left and right directions protrude rearward.

Here, the rear surface 7A of the counterweight 7 fits within the left and right vehicle width dimensions A of the lower traveling body 2 when the upper turning body 4 turns, and the rear surface 7A of the counterweight 7 and the surrounding obstacles when the upper turning body 4 turns. It is possible to avoid the interference of. As a result, the hydraulic excavator 1 realizes a small rear turn of the upper swing body 4. It should be noted that the definition of a small rear turn includes a degree in which a part of the counterweight 7 slightly protrudes from the vehicle width dimension A of the lower traveling body 2 within a range that does not cause a problem in work.

The engine 8 as a prime mover is located on the front side of the counterweight 7 and mounted on the turning frame 6. The engine 8 is mounted on the swivel frame 6 in a horizontally installed state in which a crankshaft (not shown) extends in the left and right directions, and drives a hydraulic pump 22, which will be described later. As the prime mover, an electric motor or a hybrid type prime mover in which an engine and an electric motor are combined can be used.

The cab 9 is located on the front side of the counterweight 7 and is mounted on the swivel frame 6. The cab 9 defines a driver's cab, and a driver's seat 10, a traveling lever / pedal device 11, left and right operating lever devices 12, 14 and a blade operating device 17, which will be described later, are arranged in the cab 9. There is. The cab 9 is formed in a vertically long box shape surrounded by a front portion 9A, a rear surface portion 9B, a left side surface portion 9C, a right side surface portion 9D and an upper surface portion 9E, and these front surface portions 9A, a rear surface portion 9B, a left side surface portion 9C, and a right side surface portion. The 9D and the upper surface portion 9E each have a transparent window portion. Further, the door 9F is attached to the left side surface portion 9C so as to be openable and closable, and the operator gets on and off the cab 9 by opening and closing the door 9F.

The driver's seat 10 is provided on the swivel frame 6 via a driver's seat pedestal (not shown) and is arranged in the cab 9. The driver's seat 10 is seated by an operator who operates the hydraulic excavator 1. A traveling lever / pedal device 11 is provided on the front side of the driver's seat 10, and the traveling operation of the lower traveling body 2 is controlled by operating the traveling lever / pedal device 11.

The left operation lever device 12 is attached to a left console box 13 provided adjacent to the left side of the driver's seat 10. The left operation lever device 12 includes a pressure reducing valve type hydraulic pilot valve (not shown) installed in the left console box 13 and a left operation lever 12A attached to the hydraulic pilot valve. The left operating lever 12A is provided so as to be tiltable in the forward and backward directions and in the left and right directions. For example, by tilting the left operating lever 12A in the left and right directions, the swivel motor of the swivel device 3 (FIG. (Not shown) is operated, and the left operating lever 12A is tilted forward and backward to operate the arm cylinder 5F of the working device 5.

The right operating lever device 14 is attached to a right console box 15 provided adjacent to the right side of the driver's seat 10. The right operating lever device 14 includes a pressure reducing valve type hydraulic pilot valve 14A (see FIG. 6) mounted in the right console box 15 and a right operating lever 14B mounted on the hydraulic pilot valve 14A. The right operating lever 14B is provided so as to be tiltable in the forward and backward directions and in the left and right directions. For example, by tilting the right operating lever 14B in the left and right directions, the bucket cylinder 5G of the working device 5 can be tilted. The boom cylinder 5E of the working device 5 is operated by tilting the right operating lever 14B forward and backward. A blade operating device 17, which will be described later, is provided on the right rear side of the right operating lever device 14.

Next, the soil removal device 16 provided on the lower traveling body 2 will be described.

The soil removal device 16 is provided on the track frame 2A of the lower traveling body 2. The earth removal device 16 has a V-shaped elevating arm 16A that is bifurcated at the base end side and is attached to the track frame 2A of the lower traveling body 2 so as to be swingable upward and downward, and left and right directions. A blade 16C composed of an extending rectangular plate-shaped body, the central portion on the rear surface side of which is attached to the tip side of the elevating arm 16A via a universal pin 16B, and a blade elevating cylinder 16D, an angle cylinder 16E, and a tilt cylinder 16F, which will be described later. It is composed of.

The blade elevating cylinder 16D is provided between the elevating arm 16A and the track frame 2A. The angle cylinder 16E is provided between the elevating arm 16A and the blade 16C in a state of extending in the front and rear directions on the left side of the elevating arm 16A. The tilt cylinder 16F is provided between the elevating arm 16A and the blade 16C in a state of extending left and right along the rear surface of the blade 16C.

The blade elevating cylinder 16D expands and contracts in response to the operation of the blade operating lever 19 described later, and swings the blade 16C upward and downward via the elevating arm 16A. Therefore, by lowering the blade 16C while the hydraulic excavator 1 is traveling, the earth and sand can be pushed out in the traveling direction to level the ground. The angle cylinder 16E expands and contracts by simultaneously operating the cylinder selection switch 21 and the tilt / angle operation switch 20, which will be described later, and both ends in the length direction of the blade 16C in the front and rear directions centered on the position of the universal pin 16B. Swing to. As a result, the earth and sand extruded by the blade 16C can be collectively discharged to the left side or the right side of the lower traveling body 2. The tilt cylinder 16F expands and contracts by operating the tilt / angle operation switch 20, and swings both ends of the blade 16C in the length direction upward and downward about the position of the universal pin 16B. As a result, an upward and downward gradient can be formed on the ground leveled by the blade 16C.

Next, the blade operation device 17 for operating the blade 16C of the soil removal device 16 will be described.

The blade operating device 17 is located in the cab 9 and is provided on the right side of the driver's seat 10 (see FIG. 3). The blade operating device 17 is attached to the right console box 15 and is arranged on the right side of the driver's seat 10 and at a rear position of the right operating lever device 14. Here, since the space formed between the right side surface portion 9D of the cab 9 and the driver's seat 10 is narrow, the right side surface portion 9D of the cab 9 is close to the right side of the blade operating device 17, and is located on the left side of the blade operating device 17. Is close to the right operating lever device 14. The blade operating device 17 includes a pressure reducing valve type hydraulic pilot valve 18, a blade operating lever 19, a tilt / angle operating switch 20, and a cylinder selection switch 21.

The hydraulic pilot valve 18 is located at the rear right of the right operating lever device 14 and is mounted in the right console box 15. A blade operating lever 19 is attached to the upper surface side of the hydraulic pilot valve 18. As shown in FIG. 6, the hydraulic pilot valve 18 is connected to the hydraulic pilot portions 26A and 26B of the blade elevating control valve 26 described later, and the pilot pressure is applied to the hydraulic pilot portions 26A and 26B in response to the operation of the blade operating lever 19. It is to supply. As a result, the blade elevating cylinder 16D of the soil removal device 16 expands and contracts, and the blade 16C rises or falls with respect to the track frame 2A.

The blade operating lever 19 is attached to the hydraulic pilot valve 18 and extends upward from the right console box 15. The blade operating lever 19 is composed of a bracket 19A attached to the hydraulic pilot valve 18, a lever body 19B fixed to the bracket 19A, and a grip 19C provided on the lever body 19B. The bracket 19A is made of an L-shaped bent plate body, and is attached to the hydraulic pilot valve 18 by using a bolt 19D. The lever body 19B is formed by bending a rod-shaped body into an L shape, and the base end side of the lever body 19B is fixed to the bracket 19A by means such as welding. The lever body 19B can be tilted in the front and rear directions (directions B1 and B2 in FIGS. 4 and 6) while maintaining a constant distance from the right side surface portion 9D of the cab 9.

The grip 19C of the blade operating lever 19 is attached to the tip end side (upper end side) of the lever body 19B. The grip 19C is gripped by an operator who operates the blade operating lever 19, and is composed of a rod-shaped body that is thicker than the lever body 19B as a whole. Here, at the tip of the grip 19C, an upper surface portion 19E that allows the operator seated in the driver's seat 10 to look down from above, and a back surface portion 19F that is hidden from the operator seated in the driver's seat 10 are provided. The upper surface portion 19E of the grip 19C is in a position where the operator can comfortably place his thumb when grasping the grip 19C, and the upper surface portion 19E is provided with a tilt / angle operation switch 20. On the other hand, the back surface 19F of the grip 19C is in a position where the operator can comfortably place the index finger when the grip 19C is gripped, and the back surface 19F is provided with a cylinder selection switch 21.

The tilt / angle operation switch 20 is provided on the upper surface portion 19E of the grip 19C constituting the blade operation lever 19, and is operated by the thumb of the operator. The tilt / angle operation switch 20 has, for example, a guide portion 20A extending in the left and right directions, and is a slide type that slides in the left and right directions (directions C1 and C2 indicated by arrows in FIG. 4) along the guide portion 20A. It is formed by a switch. As shown in FIG. 6, the tilt angle operation switch 20 is electrically connected to the electromagnetic pilot portions 31A and 32A of the pilot pressure control valves 31 and 32, which will be described later, respectively. The tilt / angle operation switch 20 holds a neutral position that is an intermediate portion in the left and right directions of the guide unit 20A when no operation is performed by the operator, and responds to the operation amount (movement amount) from the neutral position. The signal (electrical signal) is output to the electromagnetic pilot units 31A and 32A of the pilot pressure control valves 31 and 32.

The tilt / angle operation switch 20 is configured to operate one of the angle cylinder 16E and the tilt cylinder 16F of the soil removal device 16 selected by the cylinder selection switch 21.

The cylinder selection switch 21 is provided on the back surface 19F of the grip 19C constituting the blade operation lever 19, and is operated by the index finger of the operator. The cylinder selection switch 21 is formed by, for example, a push button type switch. As shown in FIG. 6, the cylinder selection switch 21 is electrically connected to the electromagnetic pilot unit 34A of the cylinder selection valve 34, which will be described later. The cylinder selection switch 21 outputs a signal (electric signal) to the electromagnetic pilot unit 34A of the cylinder selection valve 34 only while the push operation by the operator is being performed, and is a signal when the push operation is not performed by the operator. Stops the output of.

As a result, the cylinder selection switch 21 selects the cylinder operated by the tilt / angle operation switch 20 from the angle cylinder 16E and the tilt cylinder 16F of the soil removal device 16. For example, when the push operation for the cylinder selection switch 21 is not performed and no signal is output to the electromagnetic pilot unit 34A of the cylinder selection valve 34, the tilt angle operation switch 20 operates the tilt cylinder 16F. On the other hand, while the push operation for the cylinder selection switch 21 is performed and the signal is output to the electromagnetic pilot unit 34A of the cylinder selection valve 34, the tilt / angle operation switch 20 operates the angle cylinder 16E. ing.

Next, the hydraulic circuit for driving the blade elevating cylinder 16D, the angle cylinder 16E, and the tilt cylinder 16F of the soil removal device 16 will be described with reference to FIG.

The hydraulic pump 22 constitutes a hydraulic source together with the tank 23. The blade elevating cylinder 16D is connected to the discharge side of the hydraulic pump 22 via the main pipelines 24A and 24B, and the angle cylinder 16E and the tilt cylinder 16F are connected via the main pipelines 25A and 25B.

The blade elevating control valve 26 is provided in the middle of the main pipelines 24A and 24B connecting the blade elevating cylinder 16D and the hydraulic pump 22. The blade elevating control valve 26 has a pair of hydraulic pilot units 26A and 26B, and these hydraulic pilot units 26A and 26B are connected to the hydraulic pilot valve 18 of the blade operating device 17 via the pilot pipe lines 27A and 27B. There is. The hydraulic pilot valve 18 is connected to the pilot hydraulic source 28 via the pilot line 28A. As a result, for example, when the blade operating lever 19 of the blade operating device 17 is tilted rearward (in the direction of arrow B2 in FIGS. 2 and 4), the pilot pressure is applied to the hydraulic pilot portion 26A of the blade elevating control valve 26. The blade 16C is raised by being supplied and shrinking the blade elevating cylinder 16D. On the other hand, when the blade operating lever 19 is tilted forward (in the direction of arrow B1 in FIGS. 2 and 4), pilot pressure is supplied to the hydraulic pilot portion 26B of the blade elevating control valve 26, and the blade elevating cylinder 16D The blade 16C is lowered by the extension of the blade 16C.

The tilt / angle control valve 29 is provided in the middle of the main pipelines 25A and 25B connecting the angle cylinder 16E and the tilt cylinder 16F and the hydraulic pump 22. The tilt / angle control valve 29 has a pair of hydraulic pilot units 29A and 29B. The hydraulic pilot section 29A is connected to the pilot hydraulic source 28 via the pilot line 30A, and the hydraulic pilot section 29B is connected to the pilot hydraulic source 28 via the pilot line 30B.

The pair of pilot pressure control valves 31 and 32 are provided between the pair of hydraulic pilot units 29A and 29B of the tilt angle control valve 29 and the pilot hydraulic source 28, respectively. That is, the pilot pressure control valve 31 is provided in the middle of the pilot pipe line 30A connecting between the hydraulic pilot unit 29A and the pilot hydraulic source 28. The pilot pressure control valve 32 is provided in the middle of the pilot pipe line 30B connecting between the hydraulic pilot unit 29B and the pilot hydraulic source 28.

The pilot pressure control valve 31 is composed of, for example, an electromagnetic proportional control valve having three ports and two positions having an electromagnetic pilot unit 31A, and a signal from the tilt / angle operation switch 20 is supplied to the electromagnetic pilot unit 31A. The pilot pressure control valve 31 holds the shutoff position (a) when no signal is supplied to the electromagnetic pilot section 31A, and shuts off the supply of pilot pressure to the hydraulic pilot section 29A of the tilt angle control valve 29. On the other hand, the pilot pressure control valve 31 is switched to the supply position (b) when a signal is supplied to the electromagnetic pilot unit 31A, and the tilt angle operation switch 20 of the tilt angle operation switch 20 with respect to the hydraulic pilot unit 29A of the tilt angle control valve 29. The pilot pressure according to the operation amount is supplied.

The pilot pressure control valve 32 is composed of, for example, an electromagnetic proportional control valve having three ports and two positions having an electromagnetic pilot unit 32A, and a signal from the tilt / angle operation switch 20 is supplied to the electromagnetic pilot unit 32A. The pilot pressure control valve 32 holds the shutoff position (c) when no signal is supplied to the electromagnetic pilot section 32A, and shuts off the supply of pilot pressure to the hydraulic pilot section 29B of the tilt angle control valve 29. On the other hand, the pilot pressure control valve 32 is switched to the supply position (d) when a signal is supplied to the electromagnetic pilot unit 32A, and the tilt angle operation switch 20 of the tilt angle operation switch 20 with respect to the hydraulic pilot unit 29B of the tilt angle control valve 29. The pilot pressure according to the operation amount is supplied.

The tilt / angle switching valve 33 is located between the tilt / angle control valve 29, the angle cylinder 16E, and the tilt cylinder 16F, and is provided in the middle of the main pipelines 25A and 25B. The tilt / angle switching valve 33 includes, for example, a 6-port 2-position directional control valve having a hydraulic pilot section 33A, and the hydraulic pilot section 33A is connected to the pilot hydraulic source 28 via a pilot pipeline 33B. The tilt / angle switching valve 33 holds the tilt position (e) when the pilot pressure is not supplied to the hydraulic pilot unit 33A, and supplies the pressure oil from the hydraulic pump 22 to the tilt cylinder 16F. On the other hand, the tilt / angle switching valve 33 is switched to the angle position (f) when the pilot pressure is supplied to the hydraulic pilot unit 33A, and the pressure oil from the hydraulic pump 22 is supplied to the angle cylinder 16E.

The cylinder selection valve 34 is provided in the middle of the pilot pipeline 33B that connects the hydraulic pilot portion 33A of the tilt / angle switching valve 33 and the pilot hydraulic source 28. The cylinder selection valve 34 is composed of, for example, a solenoid valve having three ports and two positions having an electromagnetic pilot unit 34A, and a signal from the cylinder selection switch 21 is supplied to the electromagnetic pilot unit 34A. The cylinder selection valve 34 holds the shutoff position (g) when no signal is supplied to the electromagnetic pilot section 34A, and shuts off the supply of pilot pressure to the hydraulic pilot section 33A of the tilt / angle switching valve 33. On the other hand, the cylinder selection valve 34 is switched to the supply position (h) when a signal is supplied to the electromagnetic pilot unit 34A, and supplies the pilot pressure to the hydraulic pilot unit 33A of the tilt / angle switching valve 33.

Therefore, when the cylinder selection switch 21 provided on the grip 19C of the blade operation lever 19 is not pushed (when no signal is output from the cylinder selection switch 21), the cylinder selection valve 34 is in the shutoff position (when the signal is not output from the cylinder selection switch 21). g) is retained. As a result, the tilt / angle switching valve 33 holds the tilt position (e). In this state, when the tilt / angle operation switch 20 provided on the grip 19C is slid from the neutral position to the left (direction indicated by arrow C1 in FIG. 4), for example, the electromagnetic force of the pilot pressure control valve 31 is electromagnetic. A signal is supplied to the pilot unit 31A. As a result, the pilot pressure control valve 31 is switched to the supply position (b), and the pilot pressure corresponding to the operation amount of the tilt angle operation switch 20 is supplied to the hydraulic pilot unit 29A of the tilt angle control valve 29. .. Therefore, the tilt cylinder 16F is reduced by the pressure oil from the hydraulic pump 22, and the tilt operation is performed so that the left end portion of the blade 16C rotates downward.

On the other hand, when the tilt / angle operation switch 20 provided on the grip 19C is operated from the neutral position to the right (direction indicated by arrow C2 in FIG. 4), for example, the electromagnetic pilot unit 32A of the pilot pressure control valve 32 Is supplied with a signal. As a result, the pilot pressure control valve 32 is switched to the supply position (d), and the pilot pressure corresponding to the operation amount of the tilt angle operation switch 20 is supplied to the hydraulic pilot unit 29B of the tilt angle control valve 29. .. Therefore, the tilt cylinder 16F is extended by the pressure oil from the hydraulic pump 22, and the tilt operation is performed so that the right end portion of the blade 16C rotates downward.

Next, when the cylinder selection switch 21 provided on the grip 19C is pushed (when a signal is output from the cylinder selection switch 21), the cylinder selection valve 34 switches to the supply position (h). Be done. As a result, the tilt / angle switching valve 33 is switched to the angle position (f). In this state, the tilt / angle operation switch 20 provided on the grip 19C is operated from the neutral position to the left, so that a signal is supplied to the electromagnetic pilot unit 31A of the pilot pressure control valve 31. As a result, the pilot pressure control valve 31 is switched to the supply position (b), and the pilot pressure corresponding to the operation amount of the tilt angle operation switch 20 is supplied to the hydraulic pilot unit 29A of the tilt angle control valve 29. .. Therefore, the angle cylinder 16E is reduced by the pressure oil from the hydraulic pump 22, and the angle operation is performed so that the left end portion of the blade 16C rotates rearward.

On the other hand, when the tilt / angle operation switch 20 is operated to the right from the neutral position while the cylinder selection switch 21 is being pushed, a signal is supplied to the electromagnetic pilot unit 32A of the pilot pressure control valve 32. Will be done. As a result, the pilot pressure control valve 32 is switched to the supply position (d), and the pilot pressure corresponding to the operation amount of the tilt angle operation switch 20 is supplied to the hydraulic pilot unit 29B of the tilt angle control valve 29. .. Therefore, the angle cylinder 16E is extended by the pressure oil from the hydraulic pump 22, and the angle operation is performed so that the right end portion of the blade 16C rotates rearward.

The pilot pressure shutoff valve 35 is provided between the right operating lever device 14 and the pilot hydraulic source 28. That is, the pilot pressure shutoff valve 35 is provided in the middle of the pilot pipeline 28B that connects the hydraulic pilot valve 14A of the right operating lever device 14 and the pilot hydraulic source 28. The pilot pressure shutoff valve 35 is composed of, for example, a 2-port 2-position directional control valve having a hydraulic pilot unit 35A. The hydraulic pilot unit 35A is connected via the pilot line 35B in the middle of the pilot line 27B that connects the hydraulic pilot valve 18 of the blade operating device 17 and the hydraulic pilot part 26B of the blade elevating control valve 26. There is.

The pilot pressure shutoff valve 35 holds the communication position (j) when the pilot pressure is not supplied to the hydraulic pilot unit 35A, and supplies the pilot pressure from the pilot hydraulic source 28 to the hydraulic pilot valve 14A. On the other hand, in the pilot pressure shutoff valve 35, the blade operating lever 19 of the blade operating device 17 is tilted forward (in the direction of arrow B1 in FIGS. 4 and 6), and the hydraulic pilot valve 18 to the blade elevating control valve 26 are hydraulic pilots. When the pilot pressure is output to the unit 26B, a part of the pilot pressure is supplied to the hydraulic pilot unit 35A to switch to the cutoff position (k).

Assuming that the pilot pressure shutoff valve 35 is switched to the shutoff position (k), the supply of pilot pressure to the hydraulic pilot valve 14A of the right operating lever device 14 is cut off, and the right operating lever 14B of the right operating lever device 14 is operated. However, the pressure oil from the hydraulic pump 22 is not supplied to the boom cylinder 5E and the bucket cylinder 5G of the working device 5. As a result, even if the operator accidentally touches the right operation lever 14B when the blade operation lever 19 of the blade operation device 17 arranged at the rear position of the right operation lever device 14 is tilted forward, the right operation lever device The boom cylinder 5E and the bucket cylinder 5G operated by 14 can be prevented from being erroneously operated against the intention of the operator.

The hydraulic excavator 1 according to the present embodiment has the above-described configuration, and a case where earth and sand excavation work is performed using the hydraulic excavator 1 will be described below.

First, the operator gets into the cab 9 and sits in the driver's seat 10. The operator seated in the driver's seat 10 operates the traveling lever / pedal device 11 to drive the lower traveling body 2 and causes the hydraulic excavator 1 to self-propell to a desired work place. Then, the operator operates the arm cylinder 5F of the swivel device 3 and the work device 5 by the left operation lever device 12, and operates the boom cylinder 5E and the bucket cylinder 5G of the work device 5 by the right operation lever device 14. As a result, the hydraulic excavator 1 can move the work device 5 up and down while turning the upper swivel body 4 to perform excavation work of earth and sand.

Next, when the soil removal device 16 of the hydraulic excavator 1 is used to perform soil removal work or the like, the operator tilts the blade operation lever 19 of the blade operation device 17 forward. As a result, pilot pressure is supplied to the hydraulic pilot portion 26B of the blade elevating control valve 26, the blade elevating cylinder 16D extends, the blade 16C descends, and the lower end of the blade 16C touches the ground. In this state, by operating the traveling lever / pedal device 11 to drive the hydraulic excavator 1, the earth and sand in the traveling direction can be extruded by the blade 16C, and the ground leveling work, the earth and sand backfilling work, and the like can be performed. be able to.

Here, in the hydraulic excavator 1, since the blade operating device 17 is arranged close to the rear position of the right operating lever device 14, when the operator tilts the blade operating lever 19 forward, it is contrary to the intention. The right operating lever device 14 may be touched. On the other hand, in the embodiment, the pilot pressure shutoff valve 35 is provided between the right operation lever device 14 and the pilot hydraulic source 28. The pilot pressure output from the hydraulic pilot valve 18 of the blade operating device 17 is supplied to the hydraulic pilot unit 35A of the pilot pressure shutoff valve 35 when the blade operating lever 19 is tilted forward.

As a result, the pilot pressure shutoff valve 35 is switched to the shutoff position (k), and the supply of pilot pressure to the hydraulic pilot valve 14 of the right operating lever device 14 is cut off. As a result, even if the operator accidentally touches the right operating lever 14B when the blade operating lever 19 is tilted forward, the boom cylinder 5E and the bucket cylinder 5G operated by the right operating lever device 14 mean the operator. On the contrary, it is possible to prevent erroneous operation.

Next, a case where the blade 16C is tilted in order to form an upward and downward gradient on the ground leveled by the blade 16C when the ground leveling work is performed using the soil removal device 16 will be described.

When the blade 16C is tilted, the cylinder selection switch 21 provided on the grip 19C of the blade operation lever 19 is not pushed, and the cylinder selection valve 34 holds the shutoff position (g). Therefore, the tilt / angle switching valve 33 holds the tilt position (e). In this state, when the operator holding the grip 19C operates the tilt angle operation switch 20 from the neutral position to the left (direction indicated by arrow C1 in FIGS. 4 and 6), the pilot pressure control valve 31 is supplied. Switch to position (b). As a result, the pilot pressure corresponding to the operation amount of the tilt angle operation switch 20 is supplied to the hydraulic pilot unit 29A of the tilt angle control valve 29. As a result, the tilt cylinder 16F can be reduced and the blade 16C can be tilted so that the right end portion rotates upward, so that an upward slope can be formed on the ground to be leveled. ..

Similarly, with the tilt / angle switching valve 33 holding the tilt position (e), the tilt / angle operation switch 20 is moved to the right from, for example, the neutral position (direction C2 indicated by arrows in FIGS. 4 and 6). The pilot pressure control valve 32 is switched to the supply position (d). As a result, the pilot pressure corresponding to the operation amount of the tilt angle operation switch 20 is supplied to the hydraulic pilot unit 29B of the tilt angle control valve 29. As a result, the tilt cylinder 16F can be extended and the blade 16C can be tilted so that the left end portion rotates upward, so that a slope rising to the left can be formed on the ground to be leveled. ..

Next, a case where the blade 16C is angled in order to discharge the earth and sand extruded by the blade 16C to the side of the lower traveling body 2 when the ground leveling work is performed using the soil removal device 16 will be described.

When performing the angle operation of the blade 16C, the operator holding the grip 19C of the blade operating lever 19 pushes the cylinder selection switch 21 by using, for example, an index finger. As a result, the cylinder selection valve 34 is switched to the supply position (h), and the tilt / angle switching valve 33 is switched to the angle position (f). In this state, the operator operates the tilt / angle operation switch 20 from the neutral position to the left with, for example, the thumb while pressing the cylinder selection switch 21 with the index finger. As a result, the pilot pressure control valve 31 is switched to the supply position (b), and the pilot pressure corresponding to the operation amount of the tilt angle operation switch 20 is supplied to the hydraulic pilot unit 29A of the tilt angle control valve 29. .. As a result, the angle cylinder 16E can be reduced and the angle operation can be performed so that the left end portion of the blade 16C rotates rearward. Therefore, the earth and sand extruded by the blade 16C can be pushed to the left side of the lower traveling body 2. Can be discharged.

Similarly, when the operator operates the tilt / angle operation switch 20 from the neutral position to the right with the thumb while pressing the cylinder selection switch 21 with the index finger, the pilot pressure control valve 32 is in the supply position. Switch to (d). As a result, the pilot pressure corresponding to the operation amount of the tilt angle operation switch 20 is supplied to the hydraulic pilot unit 29B of the tilt angle control valve 29. As a result, the angle cylinder 16E can be extended and the angle operation can be performed so that the right end portion of the blade 16C rotates rearward. Therefore, the earth and sand extruded by the blade 16C can be pushed to the right side of the lower traveling body 2. Can be discharged.

As described above, in the blade operation device 17 according to the embodiment, when the tilt angle operation switch 20 and the cylinder selection switch 21 are provided on the grip 19C of the blade operation lever 19, and the tilt angle operation switch 20 is operated independently. By driving the tilt cylinder 16F, the blade 16C can be tilted. On the other hand, when the cylinder selection switch 21 and the tilt / angle operation switch 20 are operated at the same time, the angle cylinder 16E can be driven to perform the angle operation of the blade 16C.

Therefore, the blade operating lever 19 is simply tilted forward and backward to drive the blade elevating cylinder 16D, and the blade operating lever 19 is tilted in a direction other than the rear direction, and the grip 19C is rotated. You don't have to. Therefore, even when the blade operating device 17 is arranged in the narrow space formed around the driver's seat 10, when operating the blade operating lever 19, the operator's hand operates the right side surface portion 9D of the cab 9 or the right operation. It is possible to suppress contact with the lever device 14, and improve the operability of the blade operating device 17.

In this case, the tilt / angle operation switch 20 is provided on the upper surface portion 19E on which the thumb can be comfortably placed when the operator grips the grip 19C, and the cylinder selection switch 21 is provided when the operator grips the grip 19C. It is provided on the back 19F where the thumb can be placed comfortably. As a result, the operator can comfortably operate the tilt / angle operation switch 20 and the cylinder selection switch 21 simply by grasping the grip 19C, and the operability of the blade operation device 17 can be improved.

Moreover, in the embodiment, the pilot pressure shutoff valve 35 is provided between the right operating lever device 14 and the pilot hydraulic source 28, and when the blade operating lever 19 is tilted forward, it is output from the blade operating device 17. By supplying the pilot pressure to the hydraulic pilot unit 35A of the pilot pressure shutoff valve 35, the supply of the pilot pressure to the right operating lever device 14 is cut off. As a result, even if the operator accidentally touches the right operating lever 14B when the blade operating lever 19 is tilted forward, the boom cylinder 5E and the bucket cylinder 5G are erroneously operated against the operator's will. Since it can be suppressed, the reliability of the hydraulic excavator 1 can be improved.

Thus, according to the embodiment, the hydraulic excavator 1 includes an earth removal device 16 and a blade operation device 17 for operating the blade 16C of the earth removal device 16, and the earth removal device 16 is mounted on the lower traveling body 2. , The elevating arm 16A provided so as to swing downward, the blade 16C attached to the tip of the elevating arm 16A, the blade elevating cylinder 16D for swinging the elevating arm 16A upward and downward, and the blade 16C. It is composed of an angle cylinder 16E that swings both ends in the length direction forward and backward, and a tilt cylinder 16F that swings both ends of the blade 16C in the length direction upward and downward.

The blade operating device 17 includes a blade operating lever 19 for operating the blade elevating cylinder 16D by tilting forward and backward, and a tilt / angle operating switch provided on the blade operating lever 19 for operating the angle cylinder 16E or the tilt cylinder 16F. 20 and a cylinder selection switch 21 provided on the blade operation lever 19 to select a cylinder operated by the tilt / angle operation switch 20 among the angle cylinder 16E and the tilt cylinder 16F.

According to this configuration, the blade elevating cylinder 16D can be operated by tilting the blade operating lever 19 forward and backward, and the tilt angle operating switch 20 and the cylinder selection switch 21 provided on the grip 19C can be operated. By operating, the tilt cylinder 16F and the angle cylinder 16E can be operated. Therefore, it is not necessary to tilt the blade operating lever 19 in a direction other than the front and rear directions, or to rotate the grip 19C. Therefore, even when the blade operating device 17 is arranged in a narrow space formed around the driver's seat 10, the blade operating device 17 can be smoothly operated.

According to the embodiment, the blade operation lever 19 has a grip 19C, the tilt angle operation switch 20 is arranged on the upper surface portion 19E of the grip 19C, and the cylinder selection switch 21 is arranged on the back surface portion 19F of the grip 19C. There is. According to this configuration, the operator can comfortably operate the tilt / angle operation switch 20 with, for example, the thumb by grasping the grip 19C, and can comfortably operate the cylinder selection switch 21 with the index finger. Therefore, the operability of the blade operating device 17 can be improved.

According to the embodiment, a hydraulic pilot type left operation lever device 12 and a right operation lever device 14 for operating the swivel device 3 and the work device 5 are provided on the left side and the right side of the driver's seat 10. The blade operating device 17 is arranged on the right side of the driver's seat 10 and at a rear position of the right operating lever device 14, and the blade operating lever 19 is located between the right operating lever device 14 and the pilot hydraulic source 28. A pilot pressure shutoff valve 35 is provided that shuts off the supply of pilot pressure to the right operating lever device 14 by the pilot pressure output from the blade operating device 17 when the blade is tilted forward. According to this configuration, even if the operator accidentally touches the right operating lever 14B when the blade operating lever 19 is tilted forward, the boom cylinder 5E and the bucket cylinder 5G operated by the right operating lever device 14 can be operated. It is possible to prevent erroneous operation against the intention of the operator.

According to the embodiment, between the hydraulic pump 22, the angle cylinder 16E and the tilt cylinder 16F, hydraulic pressure is applied to the angle cylinder 16E or the tilt cylinder 16F according to the pilot pressure supplied to the pair of hydraulic pilot units 29A and 29B. A tilt angle control valve 29 for supplying pressure oil from the pump 22 is provided, and an electromagnetic pilot unit 31A, is provided between the pair of hydraulic pilot units 29A and 29B of the tilt angle control valve 29 and the pilot hydraulic source 28. A pair of pilot pressure control valves 31 and 32 for controlling the pilot pressure supplied to the hydraulic pilot units 29A and 29B of the tilt angle control valve 29 according to the signal supplied to the 32A are provided, and the tilt angle control valve is provided. Between the 29 and the tilt cylinder 16F and the angle cylinder 16E, pressure oil from the hydraulic pump 22 is supplied to one of the tilt cylinder 16F and the angle cylinder 16E according to the pilot pressure supplied to the hydraulic pilot unit 33A. A tilt / angle switching valve 33 is provided, and a tilt / angle switching valve is provided between the hydraulic pilot unit 33A of the tilt angle switching valve 33 and the pilot hydraulic source 28 according to a signal supplied to the electromagnetic pilot unit 34A. A cylinder selection valve 34 for selecting one of the angle cylinder 16E and the tilt cylinder 16F by switching 33 is provided, and the tilt / angle operation switch 20 is provided in the electromagnetic pilot portions 31A and 32A of the pilot pressure control valves 31 and 32, respectively. The signal is output, and the cylinder selection switch 21 is configured to output a signal to the electromagnetic pilot unit 34A of the cylinder selection valve 34.

According to this configuration, when the cylinder selection switch 21 is not operated and no signal is output to the electromagnetic pilot unit 34A of the cylinder selection valve 34, the cylinder selection valve 34 holds the shutoff position (g) and switches the tilt angle. The valve 33 holds the tilt position (e). In this state, the tilt angle operation switch 20 is operated, and the pilot pressure is supplied to the hydraulic pilot units 29A and 29B of the tilt angle control valve 29 via the pilot pressure control valves 31 and 32, so that the tilt cylinder 16F Can be activated.

On the other hand, when the cylinder selection switch 21 is operated and a signal is output to the electromagnetic pilot unit 34A of the cylinder selection valve 34, the cylinder selection valve 34 is switched to the supply position (h), and the tilt / angle switching valve 33 is angled. It switches to the position (f). In this state, the tilt angle operation switch 20 is operated, and the pilot pressure is supplied to the hydraulic pilot units 29A and 29B of the tilt angle control valve 29 via the pilot pressure control valves 31 and 32, so that the angle cylinder 16E Can be activated.

In the embodiment, an electromagnetic directional control valve (solenoid valve) having electromagnetic pilot units 31A and 32A is used as the pilot pressure control valves 31 and 32, and an electromagnetic valve having an electromagnetic pilot unit 34A is used as the cylinder selection valve 34. The case where it is used is illustrated. However, the present invention is not limited to this, and for example, a pilot pressure control valve and a cylinder selection valve may be configured by using a hydraulic pilot type directional control valve.

In the embodiment, the tilt cylinder 16F operates when the tilt / angle operation switch 20 is operated independently, and the angle cylinder 16E operates when the tilt / angle operation switch 20 and the cylinder selection switch 21 are operated at the same time. The case of doing this is illustrated. However, the present invention is not limited to this, for example, when the angle cylinder 16E is operated when the tilt / angle operation switch 20 is operated independently, and when the tilt / angle operation switch 20 and the cylinder selection switch 21 are operated at the same time. The tilt cylinder 16F may be operated.

In the embodiment, the case where it is applied to the crawler type hydraulic excavator 1 provided with the track 2E is illustrated. However, the present invention is not limited to this, and can be applied to, for example, a crawler type hydraulic excavator.

1 Hydraulic excavator 2 Lower traveling body 3 Swivel device 4 Upper swivel body 5 Working device 8 Engine (motor)
10 Driver's seat 12 Left operation lever device 14 Right operation lever device 16 Earth removal device 16A Elevating arm 16C Blade 16D Blade elevating cylinder 16E Angle cylinder 16F Tilt cylinder 17 Blade operating device 19 Blade operating lever 19C Grip 19E Top surface 19F Back surface 20 Tilt・ Angle operation switch 21 Cylinder selection switch 22 Hydraulic pump 28 Pilot hydraulic source 29 Tilt angle control valve 29A, 29B, 33A Hydraulic pilot section 31, 32 Pilot pressure control valve 31A, 32A, 34A Electromagnetic pilot section (pilot section)
33 Tilt / angle switching valve 34 Cylinder selection valve 35 Pilot pressure shutoff valve

Claims (3)

A self-propelled lower traveling body, an upper swivel body rotatably mounted on the lower traveling body via a swivel device, a working device provided on the upper swivel body, and a working device provided on the lower traveling body. It consists of a soil removal device
The upper swivel body includes a swivel frame, a prime mover provided on the swivel frame to drive a hydraulic pump, a driver's seat provided on the swivel frame, and blades of the earth removal device provided on the side of the driver's seat. Equipped with a blade operating device to operate
The soil removal device swings the elevating arm provided on the lower traveling body so as to swing upward and downward, the blade attached to the tip of the elevating arm, and the elevating arm in the upward and downward directions. It consists of a blade elevating cylinder that moves, an angle cylinder that swings both ends of the blade in the length direction forward and backward, and a tilt cylinder that swings both ends of the blade in the length direction upward and downward. In the construction machine
The blade operating device includes a blade operating lever that operates the blade elevating cylinder by tilting forward and backward, and a tilt / angle operating switch that is provided on the blade operating lever and operates the angle cylinder or the tilt cylinder. The blade operating lever is provided with a cylinder selection switch for selecting a cylinder operated by the tilt / angle operating switch among the angle cylinder and the tilt cylinder .
A construction machine characterized in that the blade operating lever has a grip, the tilt / angle operating switch is arranged on an upper surface portion of the grip, and the cylinder selection switch is arranged on a back surface portion of the grip. On the left side and the right side of the driver's seat, a hydraulic pilot type left operation lever device and a right operation lever device for operating the turning device and the working device are provided.
The blade operating device is arranged on the right side of the driver's seat and at a rear position of the right operating lever device.
Between the right operating lever device and the pilot hydraulic source, the supply of pilot pressure to the right operating lever device is cut off by the pilot pressure output from the blade operating device when the blade operating lever is tilted forward. The construction machine according to claim 1, wherein a pilot pressure shutoff valve is provided. Between the hydraulic pump, the angle cylinder, and the tilt cylinder, a tilt that supplies pressure oil from the hydraulic pump to the angle cylinder or the tilt cylinder according to a pilot pressure supplied to a pair of hydraulic pilot units.・ An angle control valve is provided.
Between the pair of hydraulic pilot sections of the tilt angle control valve and the pilot hydraulic source, a pilot pressure supplied to each hydraulic pilot section of the tilt angle control valve is applied in response to a signal supplied to the pilot section. A pair of pilot pressure control valves to control are provided,
Between the tilt angle control valve and the tilt cylinder and the angle cylinder, one of the tilt cylinder and the angle cylinder is supplied from the hydraulic pump according to the pilot pressure supplied to the hydraulic pilot unit. A tilt / angle switching valve that supplies pressure oil is provided.
One of the angle cylinder and the tilt cylinder is connected between the hydraulic pilot portion of the tilt / angle switching valve and the pilot hydraulic source by switching the tilt / angle switching valve according to a signal supplied to the pilot portion. A cylinder selection valve is provided to select
The tilt / angle operation switch outputs a signal to the pilot unit of each pilot pressure control valve.
The construction machine according to claim 1, wherein the cylinder selection switch is configured to output a signal to a pilot portion of the cylinder selection valve.

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