JPH1037775A - Tractor turning control device with electronic governor - Google Patents

Abstract

(57) [Summary] [PROBLEMS] When a tractor turns during tilling work, the turning performance is improved and the roughening of the field is prevented. When a turning control mode is set, a steering angle of a steering wheel is calculated by a steering angle sensor, and when the steering angle exceeds a certain value, it is determined that the body has been turned. When the airframe is turned, a control signal is output from the hydraulic control unit to the lift cylinder solenoid valve, and first, the rotary work machine is started to rise to prevent the work machine from being dragged. Subsequently, a control signal is output from the electronic governor control unit to the rack actuator, and the engine speed is reduced to reduce the traveling speed of the tractor. Further, a control signal is output from the hydraulic control unit to the left or right solenoid valve for the brake cylinder to brake the rear wheel on the inside of the turn to reduce the turning radius and improve the turning performance of the tractor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tractor equipped with an electronic governor and, more particularly, to a tractor turning control device which lifts a work implement and brakes a rear wheel inside the turn when turning. .

[0002]

2. Description of the Related Art In recent years, tractors equipped with electronic governors have been increasing. For example, the one described in Japanese Patent Application No. 1-253532 is known. The electronic governor detects the position of the control rack that adjusts the fuel injection amount with a sensor, outputs a control signal from the controller to the rack actuator according to the reading value of the throttle position sensor, and adjusts the position of the control rack. This is for electronically controlling the engine speed.

When a tractor performs a tilling operation, an electronic governor is operated by a throttle lever to maintain a full throttle state in which the engine rotates at a high speed. Then, when turning around the shore during the tilling work, the engine speed is temporarily reduced by the throttle operation, and the traveling speed of the aircraft is reduced. Also, depressing only the brake pedal on one side brakes the rear wheel inside the turn, reducing the turning radius of the machine and operating the work machine lift switch so that the work machine is not dragged. Raise to height.

The turning operation of the body is detected by a sensor,
There is also known a tractor provided with a turning control device that automatically raises a work implement and brakes a rear wheel inside the turning when the machine enters a turning state.

[0005]

Conventionally, even with a tractor provided with a turning control device, when the lifting operation of the working machine is delayed, the working machine starts turning while keeping the working machine in contact with the ground. A load is applied to the side of the machine, and the work-up portion of the work machine is left with a large inclination, which makes it difficult to finish the headland. In addition, if the operation of the electronic governor is delayed, the body turns while the engine rotates at a high speed, and there is a risk of overrun.

Here, a description will be given of the operation sequence of raising the working machine, lowering the rotation speed of the engine, and braking the inner rear wheel.
For example, if the working machine is raised after the engine speed has been reduced, the load may be large and engine stall may occur.
If the work machine is lifted after the inner rear wheel braking, the machine will turn while the work machine is in contact with the ground, so that the load is applied to the side of the work machine and the work machine Will remain largely inclined. On the other hand, if the reduction of the engine speed is performed after the inner rear wheel braking, the safety is impaired because the aircraft turns at high speed.

[0007] An unskilled worker may perform these operations in a wrong order or at almost the same time, thus deteriorating the leveling of the field and the safety of the operation. Therefore, when the tractor turns during the tilling work, a technical problem to be solved arises to prevent the roughening of the field while improving the turning performance, and also to ensure the safety of the work. The purpose is to solve this problem.

[0008]

SUMMARY OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object, and includes means for detecting a turning operation of an airframe, means for raising a working machine at the time of turning, and turning at the time of turning. In a tractor provided with a means for braking the inner rear wheel and a means for increasing / decreasing the engine speed by an electronic governor, when the body is turned, first the working machine is started to rise, and then the electronic governor is used. An object of the present invention is to provide a tractor turning control device equipped with an electronic governor for lowering the engine speed and braking the rear wheel inside the turning.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a tractor 10, in which an engine 11 is mounted in front of the tractor 10, and the engine 11
The electronic governor 12 is mounted on the side of the electronic governor. Further, a rotary working machine 14 is connected to a rear portion of the tractor 10 via a link mechanism 13.

The link mechanism 13 is a three-point link system including a top link 15 and left and right lower links 16. The distal ends of left and right lift arms 17 are connected to the left and right lower links 16 by lift rods 18, respectively. is there. When the lift arm 17 is rotated by expansion and contraction of a lift cylinder 20 provided on the upper part of the transmission case 19, the lower link 16 moves up and down, and the rotary work machine 14
Goes up and down.

On the other hand, a controller 22 is provided near the driver's seat 21. The controller 22 is provided with a position lever 23, a tillage setting dial 24, a turning control switch 25 and the like. When the turning control switch 25 is off, normal turning is performed, and when the turning control switch 25 is turned on, the mode is switched to the turning control mode. In the turning control mode, when the machine body is turned, the lifting of the work implement and the rear wheel braking inside the turning are automatically performed.

Further, a work implement elevating switch 27 is provided at a position near the steering 26, and a steering shaft 28 is provided.
The steering angle sensor 29 is installed on the vehicle. FIG. 2 is a block diagram of the turning control device. An electronic governor control unit 30 and a hydraulic control unit 31 for working machine attitude are provided inside the controller 22. The throttle operation amount is detected by a throttle position sensor 32, and the position of the control rack is detected by a rack position sensor 33. A control signal is output from the electronic governor control unit 30 to the rack actuator 34 in accordance with the value detected by the throttle position sensor 32, and the position of the control rack is adjusted to electronically control the engine speed. An increase or decrease in the engine speed is detected by an engine speed sensor 35.

On the other hand, setting signals of a position lever 23, a tillage setting dial 24, a turning control switch 25, a work implement elevating switch 27, and the like, and a detection signal of a steering angle sensor 29 are input to the hydraulic control unit 31. When a control signal is output from the hydraulic control unit 31 to the lift cylinder solenoid valve 40, the lift cylinder 20 is driven, the lift arm 17 is rotated upward, and the rotary work machine 14 is raised. When a control signal is output from the hydraulic control unit 31 to the left brake cylinder solenoid valve 41 or the right brake cylinder solenoid valve 42, the left rear wheel or the right rear wheel is braked.

When the turning control switch 25 is turned on, the mode is switched to the turning control mode, and the turning control is performed as shown in the flowchart of FIG. When the tractor 10 enters the turning control mode, the steering angle of the steering 26 is calculated by the steering angle sensor 29, and when the steering angle exceeds a predetermined value, it is determined that the body has been turned. As means for detecting the turning operation of the aircraft, such as the steering angle sensor 29 and the pitman arm angle sensor (not shown),
In addition to detecting the operation amount of a member that operates in conjunction with the turning of the body, there is a non-contact detection method such as a gyro sensor (not shown).

When the body is turned during the tilling operation, the hydraulic control unit 31 sends the lift cylinder solenoid valve 4
The control signal is output to 0, and the ascent of the rotary work machine 14 is started. This is because, when the lifting of the rotary work machine 14 is delayed, a part of the work machine is dragged to the ground and roughens the field scene.
Make a rise.

Subsequently, a control signal is output from the electronic governor control unit 30 to the rack actuator 34 to reduce the engine speed and reduce the traveling speed of the tractor 10.
If the operation of the electronic governor 12 is delayed, the tractor 10 turns while the engine rotates at a high speed, and there is a risk that the turning speed is too fast and an overrun occurs.

Further, the solenoid valve 41 for the left brake cylinder or the solenoid valve 4 for the right brake cylinder
2 to output a control signal to brake the rear wheel inside the turn. By turning the body while braking the rear wheel inside the turning, the turning radius is reduced and the turning time is shortened, and the turning performance of the tractor 10 can be improved.

When the turning of the body is completed and the steering wheel 26 is returned to the neutral position, it is determined that the tractor 10 has returned to the straight traveling state based on the detection value of the steering angle sensor 29. If so, the solenoid valve for the left brake cylinder 4
1 or the control signal to the right brake cylinder solenoid valve 42 is stopped to release the rear wheel braking inside the turning.

After the tractor 10 returns to the straight traveling state,
When the operator operates the position lever 23 or the work machine elevating switch 27, the rotary work machine 14
Descends and touches the field. At this time, the electronic governor 12 is operated by the control signal of the electronic governor control unit 30 to return to the work mode in which the engine rotates at a high speed.

As described above, the rotation speed of the engine is automatically reduced in conjunction with the turning operation of the body, and when the turning operation is completed and the rotary work machine 14 comes into contact with the ground, the rotation speed of the engine is automatically reduced again. Since the control is performed such that the tractor is raised, the turning performance and the turning operability of the tractor are improved, and safety can be secured.

FIG. 4 shows a routine for preventing the operator from forgetting to lower the work implement after the end of the turn.
When 4 has risen, the work implement descending check is performed after x seconds have elapsed after the start of the rise of the rotary work implement 14.

As a method of checking the lowering of the work machine, the angle of the lift arm 17 is detected or the position of the
, Or the operating position of the work implement elevating switch 27 is detected. It should be noted that the checking of the lowering of the work machine may be performed after x seconds elapse after the tractor 10 returns to the straight traveling state after the turning is completed.

If the work machine does not descend after the elapse of x seconds, a warning buzzer is sounded to alert the operator that the rotary work machine 14 is not descending. Therefore,
It is possible to prevent the operator from forgetting to lower the work machine that has been automatically raised during the turning control. In addition, by reliably performing the work after the end of the turn, a warning is issued when the user tries to get out of the field in the turn control mode.

The present invention can be variously modified without departing from the spirit of the present invention, and it goes without saying that the present invention extends to the modified ones.

[0025]

As described above, according to the present invention, when the tractor turns during tilling work, when the body is turned, first the work machine starts to rise, and then the engine speed is controlled by the electronic governor. , And is further automatically controlled to brake the rear wheel inside the turn. Therefore, even an unskilled worker can improve the turning performance, prevent the roughening of the field, and prevent the aircraft from turning at high speed by mistake, ensuring the safety during turning. it can.

[Brief description of the drawings]

FIG. 1 shows an embodiment of the present invention and is a side view of a tractor.

FIG. 2 is a block diagram of a turning control device.

FIG. 3 is a flowchart of turning control.

FIG. 4 is a flowchart of a routine for preventing forgetting to lower the work implement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Tractor 11 Engine 12 Electronic governor 17 Lift arm 22 Controller 25 Turning control switch 29 Steering angle sensor 30 Electronic governor control part 31 Hydraulic control part 40 Lift cylinder solenoid valve 41 Solenoid valve for left brake cylinder 42 Solenoid valve for right brake cylinder

Claims (1)

[Claims] 1. Means for detecting a turning operation of an airframe, means for raising a work machine at the time of turning, means for braking a rear wheel inside the turning at the time of turning, and means for increasing / decreasing an engine speed by an electronic governor. In the tractor, when the body is turned, the working machine starts to rise first, then the engine speed is reduced by the electronic governor, and the rear wheels inside the turn are braked. Turning control device for tractors equipped with an electronic governor.