JPH06298109A - Steering controller for tractor - Google Patents

Abstract

PURPOSE:To accurately perform steering by steering rear wheels according to the right and left inclination angle of a car body and correcting this steering while steering front wheels and rear wheels in a tractor which works while running on an inclined ground along a contour line. CONSTITUTION:In a tractor capable of 4W steering, steering front wheels 1 and rear wheels 2, a steering controller is constituted, which has an inclination sensor for detecting the right and left inclination angles of a car body and performs inclination steering control for controlling the steering angle of the rear wheels 2 according to the inclination angle of this inclination sensor and steering correction control for correcting the run a ground factor according to the soil property of this inclined ground.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering control device for a tractor, which can be used for a steering operation performed while traveling on a sloping ground in a substantially contour direction.

[0002]

2. Description of the Related Art When a tractor work is performed while traveling along a contour line on a sloping ground, the front wheel and the rear wheel are steered in the same direction.
It is possible to perform the target steering in the contour line direction by maintaining and controlling S at a position where the steering on the uphill side and the slip of the wheel on the downside are balanced with respect to the sloping ground. On the other hand, even if only the front wheels are steered, the amount of slippage of the rear wheels changes, so it is difficult to steer as desired.

According to the present invention, the steering of the rear wheels is performed by the tilt steering control according to the tilt angle of the sloping ground and the steering correction control for correcting the multiplication coefficient according to the soil condition of the sloping ground. It is trying to get the target steering done accurately.

[0004]

SUMMARY OF THE INVENTION The present invention has a 4WS steering tractor that steers front wheels 1 and rear wheels 2 and has a tilt sensor 4 for detecting a lateral tilt angle of a vehicle body 3, Inclination steering control for controlling the steering angle of the rear wheel 2 according to the inclination angle of the inclination sensor 4 and steering correction control for correcting the multiplication coefficient according to the soil condition of the slope and the like are performed. A characteristic steering control device is configured.

[0005]

Operation and Effects of the Invention While traveling in a contour line direction on a sloping ground, a target machine is steered so that a working machine mounted on the front and rear wheels 1, 2 and the vehicle body 3 passes through. By operating the steering handle, the front wheels 1 and the rear wheels 2 are steered in the same direction so as to face the rising side of the slope. At this time, the tilt sensor 4 detects the tilt angle of the vehicle body 3,
The tilt steering is controlled to a proportional angle under a constant multiplication coefficient according to the tilt angle. In this way, the front wheel 1 is steered by the steering operation by the operator, and the target wheel can be steered in the contour direction by the steering of the rear wheel 2 according to the inclination angle detected by the inclination sensor 4.

[0006] However, if the slip condition due to the hardness of the soil surface or the water content is out of the set range, the rear wheel 2 may easily slip or, on the contrary, easily rise to the steering side.
In such a case, by correcting the multiplication coefficient of the tilt steering control by the steering correction control, the steering angle of the rear wheel 2 is corrected and output, and the steering control for riding in the front wheel 1 is accurately performed. Done. Moreover, since such steering control is performed based on the correction based on the inclination angle detected by the inclination sensor 4, the steering control is easily performed, and the selection of the multiplication coefficient can be simplified.

[0007]

1 to 5, the tractor body 3 has a four-wheel steering mode 4WS in which a steering wheel 7 can steer front wheels 1 and rear wheels 2 through an orbit roll 8. It is set to 4WD, which allows four-wheel drive with engine E. Reference numeral 9 is a cockpit, and 10 is a lift arm which is mounted on a rear portion of the vehicle body 3 and which moves up and down.

The front and rear wheels 1 and 2 are steerable around the kingpin axes 11 and 12 at the left and right ends of each axle housing, and the steering arms 13 and 14 and the tie rod 1 are provided.
5, 16 and steering cylinders 19 and 20 having pistons 17 and 18 connected to the steering arms 13 and 14, and the like.
The steering hydraulic circuits 21 and 22 of 20 are provided with steering control valves 23 and 24 having solenoids, of which the steering hydraulic circuit 22 on the rear wheel 2 side is provided with a correction control valve 25 having solenoids. 26 is provided.

Reference numeral 27 is a rear wheel steering angle sensor, and 28 is a front wheel steering angle sensor. Reference numeral 29 is a front wheel steering switch for performing front wheel steering FWS, 30 is a reverse phase 4WS switch for steering the front wheels 1 and rear wheels 2 in opposite directions, and 31 is a rear wheel steering switch for steering RWS for the rear wheels 2. , 32 is a changeover switch for switching the steering control between automatic and manual, 33 is a back switch for turning on the reverse clutch, and 34 is a front wheel steering mode FWS.
The front wheel steering lamp lights up at, 35 is the reverse phase 4WS lamp at the reverse phase 4WS mode, and 36 is the rear wheel steering mode RW.
Rear wheel steering lamp that lights up with S, 37 is a changeover switch 32
Is a buzzer, which is an automatic lamp that lights up when is switched to automatic steering. The CPU is a controller having a micro computer.

In the front wheel steering mode FWS, the front wheel steering switch 29 may be turned on to carry out the steering operation of the steering wheel 7. At this time, the rear wheel 2 is fixed at the neutral position and maintains the straight traveling state, and the steering by the front wheel 1 is performed. The rear wheel steering mode RWS includes the rear wheel steering switch 3
1 is turned on, and steering operation of the steering wheel 7 is performed. At this time, the front wheels 1 are fixed at the neutral position, and the steering by the rear wheels 2 is performed. Especially, it is used when working in the form of a front mount working machine or when working in reverse.

In the reverse phase steering mode 4WS, the reverse phase 4WS is used.
By turning on the switch 30, the front wheels 1 and the rear wheels 2 can travel in opposite directions and turn. When working on a sloping ground along the contour line direction,
Switch the changeover switch to the automatic side. Steering is performed by the steering wheel 7. Since the tilt angle of the vehicle body 3 in the left-right direction is detected by the tilt sensor 4, the rear wheel 2 is automatically steered according to the tilt direction and the angle. At this time, the rear wheel 2 is steered in the same direction as the front wheel 1,
When the component force of the rear wheels 1 and 2 trying to rise on the sloped ground and the component force of slipping down in the slope direction are balanced, the target steering is achieved.

At this time, when the steering force of the front wheels 1 by the steering wheel 7 alone causes an excess or deficiency in the component force for the rear wheels 2 to rise on the sloped ground, the operator tilts the amplification volume. Adjust 6. As a result, the correction control valve 25 or 26 is output, and the steering angle of the rear wheel 2 is corrected, and the steering along the contour line direction can be performed according to the soil condition or the water content of the sloping ground. .

The inclination amplifying volume 6 is a correction control valve 25, 26 having a variable resistance and comprising a solenoid valve.
When the dial operation of the tilt amplification volume 6 is set, the steering angle by the orbit roll 8 in the hydraulic circuit 22 for steering the rear wheel 2 is adjusted, and accordingly, The steering angle of the rear wheel 2 steered by the inclination sensor 4 is corrected because the multiplication coefficient is changed, and the cutting angle of the rear wheel 2 is increased when the rear wheel 2 is slippery, for example. However, if it is difficult to slip, reduce the cutting angle.

In the 4WS having the front anti-phase steering mode, when the inclination angle of the vehicle body 3 reaches a certain value or more, the anti-phase steering switch 30 is restrained so as not to be turned on, and the reverse phase on the sloping ground is suppressed. This is intended to ensure safety by preventing the turning in the steering mode. That is, when the tilt sensor 4 detects a tilt angle of a certain value or more, the steering control valve 24 of the steering cylinder 20 that steers the rear wheel 2 is not turned on. That is,
The inclination sensor 4 does not switch to the reverse phase steering mode prior to the manual reverse phase 4WS switch 30.

When the vehicle enters an inclined ground during the operation of the steering wheel, the signal from the inclination sensor 4 locks the rear wheel steering cylinder 20 when the rear wheels 2 return to the neutral position. 1, FIG. 2, FIG. 7, and FIG. 8, the difference from the upper side is that the rear wheel steering angle sensor 27, which is a potentiometer for detecting the steering angle of the rear wheel 2, is used to control the rear wheels. By operating the correction control valves 25 and 26 in the hydraulic circuit 22,
The deviation angle from the neutral position of the rear wheel 2 in the FWS mode is corrected. In the FWS mode, the rear wheel 2 is in the neutral position, but when external force is reduced due to the inclination of the soil surface, vibration of the tractor, etc., an oil leak occurs in the control valve of the hydraulic circuit and the rear wheel 2 moves. It may deviate from the neutral position. In such a case, the rear wheel 2 is returned to the neutral position by the detection of the rear wheel steering angle sensor-27. (Fig. 7).

When the neutral position of the rear wheel 2 is deviated, it is dangerous. Therefore, the buzzer 38 is output by detecting the deviation of the neutral position of the rear wheel steering angle sensor 27 (FIG. 8). When the driver hears the warning of the buzzer 38, he / she can stop the tractor traveling and change the FWS mode to the 4WS mode to steer the rear wheel 2 to restore the neutral position.

The sensor mounting plate 4 is attached to the final case 42 at the left and right ends of the rear axle housing 41.
5, a potentiometer having a sensor arm 44 rotated by engaging with a steering arm 14 for rotating the rear wheel 2 by rotating around the kingpin axis. The rear wheel steering angle sensor 27 is attached to the sensor mounting plate 45. When the rear wheel 2 is displaced, the steering arm 14 is rotated and the sensor arm 44 of the rear wheel steering angle sensor 27 is also rotated, so that the displacement signal of the rear wheel 2 can be obtained.

In FIG. 9, the difference from the upper side is that an adjuster 39 for setting the neutral position of the rear wheel 2 is provided, and when the rear wheel 2 is displaced from the neutral position during work, the adjustment lever-4
It is carried out by changing and adjusting the set angle of the rear wheel steering angle sensor 27 by 0. Switching between the 4WS mode and the FWS mode is performed with the wheels 1 and 2 returned to the neutral position. The rear wheel steering angle sensors 27 are mounted on the final case 42 at both end portions of the rear axle housing 41. A plate arm 46 having a rear wheel steering angle sensor 27 integrally mounted thereon is mounted on a sensor mounting plate 45 which is integral with the final case 42.
Also, the plate arm 46 is rotatably provided on the axis of the potentiometer, and the plate arm 46 is rotated with respect to the sensor mounting plate 45 to rotate the rear wheel steering angle sensor 27 around the kingpin axis 11. The neutral position when the rear wheel 2 is in the straight traveling state can be set by changing the phase angle of.

In this adjustment operation, when the rear wheel 2 is directed to the slope rising side with respect to the sloped ground and the steering angle of the rear wheel 2 is deviated due to a large resistance, an alarm buzzer 38 is issued. Stops running because of a beep. The FWS mode is changed to the RWS mode, and the rear wheels 2 are slightly cut to the ascending and rising side. Adjustment is made by the adjustment lever 40, and when the buzzer 38 disappears, the adjustment is completed at this position. Returning from the RWS mode to the FWS mode again, the tractor work is started.

In FIG. 10, the rear wheel steering angle sensor 4 is provided with an adjuster 39 composed of a variable resistor, which can be adjusted by dial operation. This operation is the same as the adjustment lever-4.
It is similar to the case of 0.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a steering device.

FIG. 2 is a steering control block diagram.

FIG. 3 is a plan view of a rear axle housing part.

FIG. 4 is a rear view thereof.

FIG. 5 is a perspective view thereof.

FIG. 6 is a side view of the tractor.

FIG. 7 is a flow chart of control showing another embodiment.

FIG. 8 is a control flow chart showing an embodiment of another part.

FIG. 9 is a perspective view showing another embodiment of the rear axle housing part.

FIG. 10 is a circuit diagram for changing the neutral position of the tilt sensor.

[Explanation of reference numerals] 1 front wheel 2 rear wheel 3 vehicle body 4 tilt sensor 6 tilt amplification volume

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masanori Imai 1 Hachikura, Tobe-cho, Iyo-gun, Ehime Prefecture, Engineering Department, Iseki Agricultural Machinery Co., Ltd. Department

Claims (1)

[Claims] 1. A 4WS for steering a front wheel 1 and a rear wheel 2.
The steerable tractor has a tilt sensor 4 for detecting a left-right tilt angle of the vehicle body 3, and tilt steering control for controlling the steering angle of the rear wheel 2 according to the tilt angle of the tilt sensor 4. A steering control device for performing steering correction control for correcting the multiplication coefficient according to conditions such as the soil quality of the sloping land.