JP4089065B2 - Engine rotation control device for work vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a configuration of an engine rotation control device of an agricultural work vehicle such as a tractor, a rice transplanter, or a combine, or a construction work vehicle.
[0002]
[Prior art]
Conventionally, as disclosed in Japanese Patent Laid-Open No. 9-296737, a working machine connected to be movable up and down and a motor for changing the accelerator position of the engine are provided, and interlocked with a lifting operation of the working machine or a reverse operation of the vehicle. For example, a tractor including an engine rotation control device that reduces the engine speed is known.
[0003]
[Problems to be solved by the invention]
However, these conventional engine rotation control devices lower the engine speed and lower the engine speed when the work implement is raised during the work or the vehicle is moved backward, but this engine rotation is reduced. When the operator tries to change the accelerator position with the accelerator pedal or the accelerator lever in the state of being in the state, an excessive load is applied to the accelerator adjusting shaft and its interlocking mechanism, and there is a risk of damaging it.
[0004]
On the other hand, if a sensor for detecting the operation of the accelerator pedal or the accelerator lever is provided in the artificial operation tool, the production cost increases.
[0005]
[Means for Solving the Problems]
In view of the above problems, the present invention is configured as follows with an engine rotation control device for a work vehicle. In other words, it includes a work machine 1 that is connected to be able to move up and down, an actuator 4 that is connected to an accelerator adjustment shaft 3 of the engine 2 and adjusts the accelerator position, and a sensor 5 that detects the rotational position of the accelerator adjustment shaft 3. An accelerator pedal 6A and an accelerator lever 6B of the vehicle are connected to the accelerator adjusting shaft 3, and the accelerator position of the engine 2 is changed from the set position to the deceleration side in conjunction with the ascending operation of the work implement 1. The work vehicle is equipped with an engine rotation control device that returns the accelerator position after the machine 1 is lowered, and the detected value of the sensor 5 fluctuates while the engine rotation is decelerated in conjunction with the raising operation of the work machine 1. In some cases, an engine rotation control device for a work vehicle is provided, which includes a control means 7 for returning the actuator 4 to a state before the operation.
[0006]
In addition, it includes a work machine 1 that is connected to be able to move up and down, an actuator 4 that is connected to the accelerator adjustment shaft 3 of the engine 2 and adjusts the accelerator position, and a sensor 5 that detects the rotational position of the accelerator adjustment shaft 3. An accelerator pedal 6A and an accelerator lever 6B of the vehicle are connected to the accelerator adjusting shaft 3, and the accelerator position of the engine 2 is changed from the set position to the deceleration side in conjunction with the reverse operation of the vehicle, and the reverse operation is canceled. When the detected value of the sensor 5 fluctuates while the engine vehicle is decelerating in conjunction with the reverse operation of the vehicle, the work vehicle is provided with an engine rotation control device that returns the accelerator position. An engine rotation control device for a work vehicle, comprising control means for returning to a state before operation.
[0007]
[Operation and effect of the invention]
The engine rotation control device for a work vehicle according to claim 1 or 2 configured as described above uses the accelerator pedal 6A or the accelerator lever 6B when the actuator 4 is operated to reduce the engine speed. When there is an operation, the movement is detected by the sensor 5 and the engine rotation reduction state is immediately released, so that an excessive load is applied to the accelerator adjusting shaft 3 to prevent them from being damaged.
[0008]
In addition, the cost of parts can be reduced as compared with the configuration in which the accelerator pedal 6A or the accelerator lever 6B is provided with a sensor for detection.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described for an agricultural tractor (hereinafter, tractor 10) which is a work vehicle.
First, the overall configuration of the tractor 10 will be described.
As shown in FIG. 4, the tractor 10 includes a diesel engine 2 inside a bonnet 11, and the rotational power of the engine 2 is transmitted to a main clutch and a power transmission mechanism (a forward / reverse switching device 18, a main switch) in a transmission case 12. The vehicle is configured to travel by being transmitted to the rear wheel 13 or the front and rear wheels 14 and 13 through the transmission 19A, the auxiliary transmission 19B, and the like.
[0010]
A handle post 17 that projects the steering handle 16 is provided in front of the cockpit 15. Below the handle 16, an accelerator position of the engine 2 is set, and an accelerator lever 6 </ b> B and a forward / reverse switching lever 23 are provided so as to protrude and hold the brake position by a brake material or the like of the rotating base. In addition, a limit switch 24 is provided at the rotation base of the forward / reverse switching lever 23, and is turned on when the lever 23 is operated to the reverse position.
[0011]
Furthermore, an accelerator pedal 6A and a left and right brake pedal for independently braking the left and right rear wheels 13 are provided on the floor.
On the side of the cockpit 15, a work implement lifting lever 35 and a speed change lever 20 for changing the height of the work implement 1 are provided, and a potentiometer 36 for detecting an operation position is provided at a rotating base of the lift lever 35. A limit switch 21 that is turned on when shifting to a predetermined high speed position is provided at the rotation base of the shift lever.
[0012]
Further, an engine rotation control on / off switch 37 for turning on and off the operation of an engine rotation control device described later is provided in the vicinity of the guides of these levers.
The sensors and limit switch detectors and setting devices are connected to a controller 7 which is a control means below the cockpit 15.
The rear portion of the transmission case 12 of the tractor 10 is provided with a cylinder case 26 that houses a hydraulic cylinder 25 that is an actuator for raising and lowering the work implement. It has a configuration. Further, a three-point link mechanism 28 including a top link and left and right lower links is provided at the rear part of the vehicle body, and various working machines are connected to the link mechanism 28. On one side of the lift arm 27, a lift arm angle sensor 29 is provided at the rotation base.
[0013]
When connecting the rotary working machine 1 to the three-point link mechanism, a potentiometer type depth sensor 46 is provided on the rotary cover 45, and the tilling depth is detected by detecting the rotation angle of the rear cover 47. Yes.
As a result, the controller 7 controls the solenoid 30A of the work implement raising control valve of the hydraulic circuit or the work implement lowering control valve so that the detection angle of the work implement lifting lever 35 coincides with the set angle of the lift arm 29. The solenoid 30B is energized to perform so-called work machine position control.
[0014]
Next, the accelerator adjusting mechanism 8 on the side of the governor mechanism 40 of the engine 2 will be described with reference to FIGS.
The accelerator adjusting mechanism 8 is provided on the side of the governor mechanism 40 of the engine 2 and rotates the accelerator adjusting shaft 3 at the control rack position in the governor mechanism 40 to adjust the fuel supply amount to the engine combustion chamber. The rotation speed is changed. A control arm 41 is integrally formed with the coaxial 3 on the adjusting shaft 3, and a push-pull wire 42A connected to the accelerator pedal 6A from the rear side, a spring 44 as an elastic member, and an accelerator lever 6B are connected to the arm 41. The push-pull type wire 42 </ b> B connected to the device is mechanically coupled.
[0015]
Further, from the front side of the control arm 41, an accelerator position sensor 5 which is means for detecting the rotation position of the control arm 41 is provided via a wire 42C via a stepping type electric motor 4 which is an engine rotation adjusting actuator. It is configured to be mechanically connected via the rod 43.
The electric motor 4 is configured to be attached to the upper portion of the radiator net mounting frame 46 disposed in front of the radiator 45 inside the bonnet 11. Thereby, compared with the structure which arrange | positions the electric motor 4 below an engine etc., adhesion of dirt and dust can be prevented and durability of the motor 4 can be improved, and it is emitted when the motor 4 is continuously energized. It is easy to cool the heat. The accelerator position sensor 5 is attached to the side of the radiator net mounting frame 46 at a position substantially the same height as the control arm. In addition, the code | symbol 47 in FIG. 1 shows the air cleaner for engine intake.
[0016]
As a result, when the work implement 1 is raised by the position control while the engine rotation control on / off switch 37 is “on”, the engine rotation control is performed by energizing the electric motor 4 to control arm 41, that is, the accelerator adjustment shaft. 3 is changed from the set position of the accelerator lever 6B (two-dot chain line in FIG. 3) to the engine speed reduction side (solid line in FIG. 3) to reduce the traveling speed of the tractor 10. ing.
[0017]
Further, when the forward / reverse switching lever 23 is operated to the reverse position and the limit switch 24 is turned on, the electric motor 4 is driven and the control arm 41 is further rotated to the deceleration side to reduce the traveling speed of the tractor 10. It has become.
Note that either the lifting operation of the work machine 1 or the deceleration operation by the reverse operation of the tractor 10 may be executed according to the model specification of the tractor 10, or either of them may be executed. If one side is in actual operation, that is, if the engine rotation is being decelerated, a further deceleration by the other operation may be canceled.
[0018]
Next, the control system of the tractor 10 will be described based on the block diagram of FIG.
The controller 7 of the tractor 10 includes a CPU for processing various signals, a RAM for temporarily storing these signal information, an EEPROM for storing various control programs, a timer clock, and the like.
[0019]
The controller 7 has a potentiometer 36, a lift arm angle sensor 29, an accelerator position sensor 5, and an engine rotation control on / off switch 37 for turning on / off the operation of the engine rotation control device. A limit switch 24 at the base of the forward / reverse switching lever 23, a limit switch 21 at the base of the shift lever 20 and the like are connected, and solenoids 30A and 30B of proportional control valves for raising or lowering the lift arm 27 are connected to the output part. Etc. are connected.
[0020]
The engine rotation control device of the tractor 10 configured as described above is executed as shown in the outline of the control program shown in FIGS.
When the power of the tractor 10 is turned on, the connection state and setting state of various sensors and setting devices are read, and it is determined whether or not the engine rotation control on / off switch 37 and the speed change lever 20 are below a predetermined level that can be assumed to be the working speed. If these are YES, the current accelerator position is stored.
[0021]
The engine speed control includes a control for decelerating the engine speed in conjunction with the ascent of the work machine 1 and a control for decelerating the engine speed in conjunction with the reverse operation of the tractor.
As shown in FIG. 8, the engine rotation control device linked to the ascending operation of the work machine 1 first determines whether or not the current engine speed is reduced in STEP 1, and if this is YES, the operation of the motor 4 is performed. Jump to STEP5. If the determination is NO, after detecting the work implement raising operation, the electric motor 4 is driven to decelerate the engine speed (STEP 2 and STEP 3). As a result, the engine speed of the tractor 10 decreases and the vehicle speed is reduced.
[0022]
At the same time, time measurement is started by the internal timer of the controller 7 (STEP 4).
Here, whether or not accelerator adjustment has been performed by the operation of the accelerator pedal 6A or the accelerator lever 6B is determined based on the variation in the detection value of the sensor 5. If this determination is YES, it is determined whether the operation delay of the motor 4 or the time during which the mechanical connection portion rattles due to this operation has settled (for example, about 2 seconds) has elapsed, and this is YES Then, the electric motor 52 is returned to the initial state, and the engine speed is returned to the initial state (STEP 7).
[0023]
When the work machine 1 is lowered, the engine rotation returns to the initial state.
Further, as shown in FIG. 9, the engine rotation control device linked to the reverse operation of the tractor 10 that is subsequently executed first determines whether or not the current engine speed is reduced in STEP 1 as described above, If this is YES, it is determined that the motor 4 is operating and jumps to STEP5. If the determination is NO, it is determined whether or not the reverse operation, that is, whether or not the limit switch 24 provided at the base of the forward / reverse switching lever 23 is ON, and when this is YES, the electric motor 4 is driven. Then, the engine speed is decelerated (STEP 2, STEP 3). As a result, the engine speed of the tractor 10 decreases and the vehicle speed is reduced.
[0024]
At the same time, time measurement is started by the internal timer of the controller 7 (STEP 4).
Here, whether or not accelerator adjustment has been performed by the operation of the accelerator pedal 6A or the accelerator lever 6B is determined based on the variation in the detection value of the sensor 5. If this determination is YES, it is determined whether or not a time (for example, about 2 seconds) during which the operation delay of the motor 4 or the electrical processing due to this operation or the backlash of the mechanical connection part settles has elapsed, for example, When the answer is YES, the electric motor 52 is returned to the initial state, and the engine speed is returned to the initial state (STEP 7).
[0025]
When the reverse operation is released, that is, when the limit switch is turned off, the electric motor 52 is returned to the initial state, and the engine speed is returned to the initial state.
The tractor 10 configured as described above is configured to mechanically connect the electric motor 4, the accelerator position sensor 5, the accelerator lever 6 </ b> A, and the accelerator pedal 6 </ b> B to the accelerator adjustment shaft 3, thereby providing an engine rotation control device. It can be configured at low cost. Further, when an operation with the accelerator pedal 6A or the accelerator lever 6B is performed while the electric motor 4 is operated and the engine speed is being reduced, the accelerator position sensor 5 detects the problem in such a configuration. Since the engine rotation reduction state is released immediately after the movement is detected, it is possible to prevent the accelerator adjusting shaft 3 from being overloaded and damaging these devices or the connecting members.
[0026]
In this embodiment, since the motor 4 is released after a certain period of time after the output of the motor 4, the control mechanism detects a sensor caused by an electrical or mechanical delay. Value fluctuations can be eliminated.
Compared to a configuration in which a sensor is provided for each of the accelerator pedal 6A or the accelerator lever 6B and this operation is detected, the parts cost can be reduced.
[Brief description of the drawings]
FIG. 1 is a side view of the inside of a bonnet.
FIG. 2 is a front view of the inside of the bonnet.
FIG. 3A is a side view showing an accelerator adjustment mechanism on an engine side.
(B) The top view which shows the accelerator adjustment mechanism of an engine side part.
FIG. 4 is an overall side view of the tractor.
FIG. 5 is a diagram showing a conduction mechanism of a tractor.
FIG. 6 is a diagram illustrating a connection state of a controller.
FIG. 7 is a flowchart showing an overall outline of engine rotation control.
FIG. 8 is a flowchart showing an outline of engine rotation control related to lifting and lowering of the work implement.
FIG. 9 is a flowchart showing an outline of engine rotation control related to a reverse operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rotary work machine 2 Engine 3 Accelerator adjustment shaft 4 Electric motor 5 Accelerator position sensor 6A Accelerator lever 6B Accelerator pedal 7 Controller 8 Accelerator adjustment mechanism

Claims (2)

Detecting the working position ( 1 ) connected up and down, the actuator ( 4 ) connected to the accelerator adjustment shaft ( 3 ) of the engine ( 2 ) and adjusting the accelerator position, and the rotation position of the accelerator adjustment shaft ( 3 ) together and a sensor (5) to the vehicle accelerator pedal to the accelerator control shaft (3) (6A), and connecting the accelerator lever (6B), in conjunction with the rise operation of the working machine (1) was changed to the deceleration side than the set position of the accelerator position of the engine (2), the working machine a work vehicle having an engine rotation control device for returning the same accelerator position after lowering of the (1), the working machine ( during deceleration of the engine rotates in conjunction with the rise operation 1), when the detected value of the sensor (5) is varied, the Bei control means (7) for returning to the state before operating the actuator (4) Engine control device for a working vehicle, characterized in that the. Detecting the working position ( 1 ) connected up and down, the actuator ( 4 ) connected to the accelerator adjustment shaft ( 3 ) of the engine ( 2 ) and adjusting the accelerator position, and the rotation position of the accelerator adjustment shaft ( 3 ) together and a sensor (5) to the the accelerator control shaft (3) connecting the vehicle accelerator pedal (6A), and the accelerator lever (6B), in conjunction with the reverse operation of the vehicle, the engine (2) The work vehicle is equipped with an engine rotation control device that changes the accelerator position of the vehicle to a deceleration side from the set position and restores the accelerator position after canceling the reverse operation, and rotates the engine in conjunction with the reverse operation of the vehicle. during deceleration, when the detection value of the sensor (5) is varied, the work vehicle comprising the control means to return to the state before operating the actuator (4) (7) Engine control unit.

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