JP3202030B2 - Transmission control mechanism for tractor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for controlling various parts of a tractor by a control signal obtained from an electronic governor mechanism when an engine having an electronic governor mechanism is mounted on the tractor.

[0002]

2. Description of the Related Art Conventionally, a technology in which an electronic governor mechanism is mounted on an engine is known. Further, in a tractor, a technology provided with a hydraulic clutch type transmission device and a technology of performing forward / reverse switching by a hydraulic clutch type switching mechanism are also known.

[0003]

SUMMARY OF THE INVENTION According to the present invention, an electronic signal of an electronic governor mechanism provided for controlling an engine is used as it is, and is used for controlling each part of a tractor. , The tractor is controlled efficiently by the signal of the electronic governor mechanism.

[0004]

The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described. In claim 1, the fuel rack 10 is
Electronic governor electrically controlled by actuator 9
-Equipped with engine E equipped with mechanism A,
The pressure clutch L and the reverse hydraulic clutch R are
VL and reverse switching valve VR.
Switching between the valve VL and the reverse switching valve VR.
Forward / backward switching device provided by the switch 21.
In a tractor to which the speed detector 20 is attached,
When the changeover switch 21 is operated to the reverse side, the reverse hydraulic
When the switch R is joined, the rotation speed of the engine E is high.
It rises above the high-speed rotation set by the speed detector 20.
To be controlled by electronic governor mechanism A
It was done.

[0005] In claim 2, the fuel rack 10 is
Electronic governor electrically controlled by
Equipped with an engine E equipped with a
Hydraulic clutch switched by the forward switch 21
Operated by the forward / reverse switching device and the PTO on / off switch 23.
And a hydraulic PTO clutch 24 to be made .
Seat switch that detects the operator's sitting on seat S
In the tractor where the 22 is located, the operator
When the engine is not seated at S, the engine speed
Down to the vicinity of the
Even if the switch 21 or the PTO on / off switch 23 is operated,
Low-speed switching bar that switches the hydraulic clutch type forward / reverse switching device
Lube VL, reverse switching valve VR, and hydraulic PTO
The PTO clutch control valve VP that operates the switch 24 operates.
An electric circuit is configured so as not to exist .

[0006]

The present invention is constructed as described above, and performs the following operations. When the height is changed by the height change device, the speed reduction ratio of the height is approximately 1.2. Therefore, if the speed drops at a stretch, the shock based on the downshift is large and the discomfort is strong. .

According to the first aspect of the present invention, when the high speed detector 20 is mounted and the hydraulic clutch type forward / reverse switching device is operated to the reverse side, control is performed so as to prevent a high speed exceeding a certain level. It was done. According to the second aspect of the present invention, when the transmission case M is not seated, the engine speed is made to stand by as idling rotation.
Are turned on and the PTO on / off switch 23 is not turned on.

[0008]

Next, an embodiment of the present invention will be described. FIG. 1 is a side view of a tractor equipped with the speed change control mechanism of the present invention, FIG. 2 is a side sectional view of an electronic governor mechanism A, FIG. 3 is a front view of the electronic governor mechanism A, and FIG. It is a drawing showing an example of a map. An engine E is disposed inside the hood at the front of the tractor, and an electronic governor mechanism A is attached to a side surface of the engine E.
And the accelerator lever 14 near the steering wheel
And an accelerator lever sensor 5 are disposed. Also, the clutch pedal 2 is located below the steering handle.
7 and the clutch pedal 27 is provided with a stroke detector 2.
6 are provided. Further, inside the transmission case M, a forward / reverse switching device and a high / low switching device constituted by a hydraulic clutch type transmission are arranged. Further, a seat switch 22 is provided in the seat S to enable safety control. A rotary tillage device is provided as the work machine R.

2 and 3, an electronic governor mechanism A
Will be described. The electronic governor mechanism A is an engine E
The magnetic rotating body 12 is fixed to a cam shaft 16 of the fuel pump. The rotation of the cam shaft 16 is detected by the rotation speed detection sensor 1 of the magnetic rotator 12 to obtain the engine rotation speed. The fuel supply amount of the electronic governor mechanism A is adjusted by moving the fuel rack 10 left and right.
Is driven by the rack actuator 9. The fuel rack 10 moved by the rack actuator 9
The rack position sensor 2 detects the position of the vehicle and detects the fuel supply amount. A rack bar 11 connected to the fuel rack 10 is inserted through the rack position sensor 2 and the rack actuator 9.

Next, a control curve of the engine E by the electronic governor mechanism A will be described with reference to FIG. In the engine E, the engine output and the shaft torque are determined by the injection amount and the injection timing of the fuel injection pump and the engine speed. The fuel injection amount is adjusted by sliding the fuel rack 10 by the rack actuator 9. And it is obtained by measuring the injection amount based on the position of the fuel rack 10 and the engine speed. The injection timing is adjusted by a timing adjustment actuator (not shown). The engine speed is detected by a speed detection sensor 1. Accelerator lever 1 for operator in electronic control unit G
By rotating the rotation 4, an instruction of the number of rotations is issued via the accelerator lever sensor 5. As the electronic control unit G, a microcomputer is used, and a program ROM storing a control program is arranged. In addition, a data ROM storing various data required for control calculation such as speed fluctuation rate characteristics is arranged.

The data rom includes a set value of an engine speed arbitrarily set according to a position of an accelerator lever 14 operated by an operator by himself / herself, and a speed variation of an actual speed according to a load. Rate characteristic,
Different work contents are stored in the form of arithmetic expressions or numerical tables. Regarding the speed fluctuation rate, the set value and the actual value of the engine speed are recognized, then the mode set by the operator is recognized, and the target rack position to be set is calculated by the droop rate map according to the mode. . A signal for setting the actual rack position to the corrected target rack position is output to the rack actuator 9,
The fuel rack 10 is automatically adjusted, and the operation is performed within a range of a predetermined speed fluctuation rate.

Normally, control is performed along a map d of the droop control shown in FIG. 4 in order to recognize a predetermined speed fluctuation, so that the fuel rack 10 changes and the shaft torque changes. That is, the engine speed fluctuates up and down to keep the load factor constant. The speed variation characteristic is selected according to the mode of the work content. When constant speed operation is required, the fuel consumption is increased or decreased and the engine speed is kept constant along the map i of the isochronous control in order to keep the engine speed constant. In addition, a constant rotation operation is performed. Also,
Even in the case of isochronous control, especially in the case of special work, when the load increases and it is close to the maximum shaft torque, reverse droop control that increases the rotation speed and shaft torque to prevent engine stall is performed. It is also possible to select the map r.

FIG. 5 is a skeleton diagram of a configuration in which a high / low speed shift and a reverse speed shift are arranged as a hydraulic clutch type transmission device, which is arranged inside a transmission case M of a tractor, FIG. 6 is a control block diagram, and FIG. FIG. 8 is a flowchart showing another control technique, and FIG. 8 is a drawing showing another control. In FIG. 5, while the rotation from the engine E is disconnected and connected by the main clutch 25, the low-speed hydraulic clutch L, the high-speed hydraulic clutch H, and the reverse hydraulic clutch R switch between high and low speeds and reverse. A control valve for operating each hydraulic clutch is provided. A high-speed switching valve VH for connecting and disconnecting the high-speed hydraulic clutch H, a main switching valve VM for connecting and disconnecting the main clutch 25, a low-speed switching valve VL for connecting and disconnecting the low-speed hydraulic clutch L, and a reverse switching valve VR for connecting and disconnecting the reverse hydraulic clutch R. is there.

Referring to FIG. 6, a control block diagram of the present invention will be described. According to the present invention, in the prior art, there is no mutual communication of electronic signals between the electronic governor mechanism A and the hydraulic clutch type high / low / reverse speed change control mechanism. Governor mechanism A and high / low
It is possible to exchange electronic signals with the reverse shift control mechanism. The switching control of the high-speed switching valve VH, the reverse switching valve VR, and the low-speed switching valve VL is performed based on signals from the rack position sensor 2 and the rotation speed detection sensor 1 of the electronic governor mechanism A. Conversely, the rack position sensor 2 and the rack actuator 9 are operated by operating the low-speed switching valve VL, the reverse switching valve VR, and the high-speed switching valve VH.

The operation will be described with reference to the flowchart shown in FIG. After "start", "initial setting" is read, and then it is determined whether "sensor check OK". If not, an alarm is sounded. Next, the engine speed ER is read by the engine speed sensor 1. Next, it is determined whether the low-speed hydraulic clutch L and the high-speed hydraulic clutch H are operated. When the "high-low SW is operated from high to low", a signal is first sent to the electronic governor mechanism A to set the command speed NER to 1.2 times the engine speed ER. At the same time, the high-speed switching valve VH is turned off, and then the engine speed ER
Is read and compared with the commanded rotation speed NER, and when the rotation speed becomes equal to or more than the same, the low speed switching valve VL is turned on. Conversely, when the “high-low SW is operated from low to high”, the engine speed ER is reduced to a command speed NER multiplied by 0.83, and the low-speed switching valve VL is turned off.
The engine speed ER is read as FF, compared with the command speed NER, and when it becomes equal to or less than the command speed NER, the high-speed switching valve VH is turned on.

In FIG. 8, unlike the flow chart of FIG. 7, the engine speed is not increased or decreased all at once to the same as the high / low speed ratio, but is changed to the speed ratio between the high / low speed ratios. Embodiments are disclosed that are configured to increase or decrease the number. That is, in the case of high to low, the engine speed is not 1.2 times, but the intermediate 1.
It is multiplied by one. Conversely, if the transition is from low to high, 0.
Instead of 83, it rises to 0.9 times in the meantime. Thus, the shock at the time of high / low gear shift is reduced to half.

[0017] Next will be described in FIGS. 9 and 10. FIG. 9 is a skeleton diagram showing a hydraulic clutch mechanism for switching between forward and backward movement, and FIG. 10 is a block diagram showing the technology of the second embodiment. The low-speed hydraulic clutch L and the reverse hydraulic clutch R are switched between the low-speed switching valve VL and the reverse switching valve VR. The switching between the low speed switching valve VL and the reverse switching valve VR is performed by the forward / reverse switching switch 21. In the configuration provided with the hydraulic clutch type forward / reverse speed change mechanism having the above-described configuration, the present invention includes the high-speed detector 20. The electronic governor mechanism A is configured to be controlled so that the rotation speed of E does not increase. That is, when the forward / reverse selector switch 21 is operated to the reverse side and the reverse hydraulic clutch R is engaged , the rotation speed of the rotation speed detection sensor 1 does not exceed a predetermined set rotation speed by the electronic governor mechanism A. It is automatically controlled as follows.

Next, a description 11-Figure 12.
FIG. 11 is a skeleton diagram of a hydraulic clutch type forward / reverse transmission and a PTO power connecting / disconnecting device, and FIG. 12 is a control block diagram showing the technology of claim 3. That is, in the technology,
A seat switch 22 is provided at the seat S of the tractor. Then, the presence or absence of an operator is detected by the seat switch 22 of the seat S, and when the operator is not seated on the seat S based on the signal, the engine speed is reduced to near idling and the system is configured to stand by. It was done. When the operator is not seated on the seat S, the low speed switching valve VL, the reverse switching valve VR, and the PTO clutch control valve VP are not operated even if the forward / reverse switch 21 or the PTO on / off switch 23 is operated. And an electric circuit.

Next, a description will be given with reference to FIGS.
13 is a drawing showing a change in clutch pressure when the forward / backward changeover switch 21 is operated by operating the clutch pedal 27. FIG. 14 is a diagram showing a case where only the forward / backward changeover switch 21 is operated without operating the clutch pedal 27. 4 is a drawing showing a process of increasing the clutch pressure of FIG. FIG. 13 shows the clutch pedal 27.
Is operated to operate the forward / reverse changeover switch 21 so that the stroke detector 26 of the clutch pedal 27 changes the clutch pressure. That is, the clutch pressure becomes zero at the position where the clutch pedal 27 is depressed, and the pressure increases as the clutch pedal 27 is returned to the original position, and the hydraulic clutch is engaged. If the clutch pedal 27 is operated without the clutch pedal 27 and only the forward / reverse selector switch 21 is operated, the relief pressure is increased by the pressure regulating valve so that the pressure increases over time so that the pressure does not increase immediately after the operation. Adjustable.

Next, a description will be given with reference to FIGS. FIG. 15 is a hydraulic circuit diagram for controlling the main clutch 25,
16 is an electric circuit diagram, FIG. 17 is a control block diagram showing the technology of claim 3, FIG. 18 is a control flowchart diagram, FIG. 19 is a diagram showing clutch pedal stroke and engine speed, and FIG. FIG. 21 is a drawing showing the relationship between the stroke and the clutch pressure, and FIG. 21 is a drawing showing the relationship between the accelerator pedal stroke and the vehicle speed.

The clutch pedal 27 has a stroke detector 2
6, the pressure increase in the main clutch 25 is controlled by the proportional pressure reducing valve 28 based on the detected stroke. Thus, the engine speed corresponding to the depression of the clutch pedal 27 is also controlled. The stroke detector 26 is constituted by a potentiometer as shown in FIG. Controlling the pressure of the main clutch 25 by depressing the clutch pedal 27 draws a curve similar to FIG. 13 described in the case of forward / reverse control.

The relationship between the stroke detector 26 of the clutch pedal 27 and the control of the engine speed is as shown in FIG. That is, when the clutch pedal 27 is depressed, the engine speed decreases. As the user steps down, the pressure in the main clutch 25 decreases and the main clutch 25 is disconnected. When the engine speed drops, the engine brake is applied. When the clutch pedal 27 is gradually returned from the depressed state,
After the main clutch 25 is connected near the idle speed, the speed gradually increases and returns to the speed set by the accelerator lever 14.

Next, control of the accelerator pedal stroke and the pressure of the main clutch 25 will be described with reference to FIGS. When the accelerator pedal 29 is depressed, the pressure in the main clutch 25 increases, and the clutch is connected. The engine speed N is equal to the accelerator pedal 29
Increases with the stroke of the stroke. Conversely, when the accelerator pedal 29 is returned from the depressed state, the clutch starts to be disengaged from a certain pedal position, and the accelerator pedal 2
If step 9 is not depressed, the main clutch 25 is disconnected and enters the neutral state. The engine speed also decreases with the stroke of the accelerator pedal 29. It is also possible to replace the accelerator pedal 29 with the accelerator lever 14.

[0024]

As described above, the present invention has the following advantages. It is configured as in claim 1.
Therefore , conventionally, in the forward / reverse switching device having the same forward / reverse speed, when the reverse speed is regulated, the high-speed position of the shift lever is restrained. This reverse high-speed check device is complicated, and if erroneous operation is performed, there is a case where it is confused that the shift lever does not enter reverse. Since the reverse high-speed check device of the present invention is electrically configured, it can be easily performed. In addition, when switching between forward and reverse, the friction plate's joining state changes from the maximum rotation of the forward movement to the maximum rotation of the reverse movement, which reduces the durability of the friction plate. By doing so, it is possible to prevent the occurrence of seizure or the like of the friction plate of the reverse hydraulic clutch R.

According to the second aspect of the present invention, when the operator is not seated, the engine speed is idling, so that the engine brake is applied to the fuselage, and the running tractor is decelerated. It stops faster than disengaging the clutch. If the operator is not seated, the hydraulic PTO clutch 2
It is safe because 4 is disconnected.

[Brief description of the drawings]

FIG. 1 is a side view of a tractor equipped with a rotary tilling device as a working machine.

FIG. 2 is a side sectional view of the electronic governor mechanism A.

FIG. 3 is a side view of the electronic governor mechanism A.

FIG. 4 is a diagram showing an example of a control map by an electronic governor mechanism A.

FIG. 5 is a skeleton diagram of a configuration in which a high / low speed shift and a reverse speed shift are arranged as a hydraulic clutch type transmission device, which is arranged inside a transmission case M of the tractor.

FIG. 6 is a control block diagram.

FIG. 7 is a flowchart showing a control technique according to claim 1;

FIG. 8 is a diagram showing another control.

FIG. 9 is a skeleton diagram showing a hydraulic clutch mechanism for switching between forward and backward movement.

FIG. 10 is a block diagram showing the technique of claim 2;

FIG. 11 is a skeleton diagram of a hydraulic clutch type forward / reverse transmission and a PTO power connection / disconnection device.

FIG. 12 is a control block diagram showing the technique of claim 3;

FIG. 13 is a drawing showing a change in clutch pressure when the forward / reverse selector switch 21 is operated by operating the clutch pedal 27.

FIG. 14 is a drawing showing a process of increasing the clutch pressure when only the forward / reverse selector switch 21 is operated without operating the clutch pedal 27.

15 is a hydraulic circuit diagram for controlling the main clutch 25. FIG.

FIG. 16 is an electric circuit diagram.

FIG. 17 is a control block diagram showing the technique of claim 3;

FIG. 18 is a control flowchart similarly.

FIG. 19 is a drawing showing a clutch pedal stroke and an engine speed.

FIG. 20 is a view showing a relationship between an accelerator pedal stroke and a clutch pressure.

FIG. 21 is a diagram showing a relationship between an accelerator pedal stroke and a vehicle speed.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 rotation speed detection sensor 2 rack position sensor 3 lift angle sensor 5 accelerator lever sensor 9 rack actuator 10 fuel rack 11 rack bar 12 magnetic rotating body 21 forward / reverse changeover switch 22 sheet switch 23 PTO on / off switch 24 hydraulic PTO clutch 25 main Clutch 26 Stroke detector 27 Clutch pedal 28 Proportional pressure reducing valve 29 Accelerator pedal H High-speed hydraulic clutch L Low-speed hydraulic clutch R Reverse hydraulic clutch VH High-speed switching valve VL Low-speed switching valve VR Reverse switching valve ER Engine speed NER Command speed

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02D 29/02 311 F02D 29/02 311B 41/04 380 41/04 380G F16D 48/02 F16H 61/04 F16H 61/04 F16D 25 / 14 640E // F16H 63:40 (56) References JP-A-2-42146 (JP, A) JP-A-61-125930 (JP, A) JP-A-52-156273 (JP, A) JP 60-53431 (JP, A) JP-A 62-30935 (JP, U) JP-A 60-10913 (JP, Y2) (58) Fields investigated (Int. Cl. ⁷ , DB name) B60K 28/04 B60K 41/00 F02D 1/02 F02D 11/10 F02D 29/00-29/02 F02D 41/04 380 F16D 48/02 F16H 61/04

Claims (2)

(57) [Claims] 1. A fuel supply system comprising: a rack actuator;
9 has an electronic governor mechanism A that is electrically controlled by
Engine E, and a low-speed hydraulic clutch L and rear
The reverse hydraulic clutch R is switched between the low speed switching valve VL and the reverse
Operated by valve VR, reverse switching with low speed switching valve VL
The switching of the switching valve VR is performed by the forward / reverse selector switch 21.
And a high-speed detector 20.
In the mounted tractor, the forward / reverse selector switch 21
Is operated to the reverse side, and the reverse hydraulic clutch R is engaged.
In this case, the rotation speed of the engine E is
In order not to rise above the higher speed setting,
A tractor speed change control mechanism configured to be controlled by a governor mechanism A. 2. The fuel rack 10 is mounted on a rack actuator.
9 has an electronic governor mechanism A that is electrically controlled by
Engine E and a forward / reverse selector switch 21
Hydraulic clutch type forward / reverse switching device operated by switching
And a hydraulic P operated by the PTO on / off switch 23
A TO clutch 24 is provided.
A seat switch 22 for detecting seating of the vehicle
When the operator is not seated in the seat S
Reduces the engine speed to near the idling speed.
To make the vehicle stand by.
Even if the O ON / OFF switch 23 is operated, the hydraulic clutch type
Low speed switching valve VL for switching the reverse switching device and reverse off
Operating the exchange valve VR and the hydraulic PTO clutch 24
Electrical control so that the PTO clutch control valve VP does not operate.
A transmission control mechanism for a tractor , comprising a road .