JPH0837811A - Steering brake control device for tractor - Google Patents

Abstract

PURPOSE:To contrive the safety of an operation by exerting an steering brake by detecting an uplift of a working vehicle over the surface of a soil with a depth sensor on turning the tractor by exerting the steering brake to rear wheels. CONSTITUTION:This brake control device comprises lifting up a lift arm 2 for elevating and descending of a working machine according to an operating angle of a steering handle 1, together with operating the turning of a tractor by exerting an steering brake 4 of rear wheels 3, and braking the steering brake 4 by detecting a standard height in a vicinity of the surface of a soil with a depth sensor 5 capable of detecting the working depth of the working machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering brake control device for a tractor.

[0002]

2. Description of the Related Art In tractor work, when turning at a field end or the like, a working arm is automatically lifted by a lift arm according to a steering angle of a steering handle to apply a steering brake. There is a form of interlocking so as to make it work, but when deep cultivating in a rotary cultivator, which is a working machine, even if the lift arm is lifted by steering the steering wheel, the rotary cultivator will stay on the soil surface. It may not be completely levitated, and when steering and turning in this state, the rotary tiller began to scratch the soil laterally, receiving resistance,
In some cases, the plowing claws may be damaged.

[0003]

According to the present invention, a steering arm 1 raises a lift arm 2 for raising and lowering a working machine according to a steering angle of a steering handle 1, and a steering brake 4 of a rear wheel 3 works to steer a steering wheel. In the tractor, the steering brake control device is characterized in that the steering brake 4 is braked by detecting the reference height near the soil surface of the depth sensor 5 that detects the working depth of the working machine.

[0004]

When the steering handle 1 is steered during steering turning, when the steering angle reaches a certain value or more, the lift arm 2 is lifted, and the working machine is working. To be done. When the working machine is lifted and the reference height near the soil surface is detected, the steering brake 4 is braked, the rotation of the rear wheel 3 on the turning side is stopped, and a sharp turn is performed.

As described above, the steering turn of the tractor is performed not only by the turning angle of the steering wheel 1 but also by the fact that the working machine has floated above the ground surface detected by the depth sensor 5 and the steering brake 4 works. Therefore, it is possible to carry out a safe turning without the work machine described above being scratched laterally in the soil. Moreover, since the effect of the steering brake 4 is also served by the depth sensor 5 for detecting the working depth of the working machine, the structure is simplified.

[0006]

[Example] The tractor body 6 is a steering wheel 1
It has a pair of left and right front wheels 7 and a pair of left and right rear wheels 3 that can be steered, and can drive the front and rear wheels 7, 3 by driving the engine in the hood 8. 9
Is a cockpit and 10 is a fender. Steering brake 4
Is provided during transmission from the differential device of the rear wheel 3 to the left and right axles 11, and by rotating the left and right brake arms 12, the steering brake 4 on the rotating side is activated and the axles 11 and The rear wheel 3 is braked.

The brake arm 12 is interlocked with the brake rods 14 of the left and right opposing brake petals 13, and the hydraulic cylinder 15 which is an actuator is interlocked, and the hydraulic pressure of the hydraulic cylinder 15 is output by the output from the controller. The steering brake 4 can also be braked by. Reference numerals 37 and 38 are elongated holes for engaging and guiding the connecting pins 39 and 40 of the brake rod 14 and the hydraulic cylinder 15.

At the rear part of the vehicle body 6, a three-point link mechanism consisting of a pair of left and right lower links 16 and a top link 17 is connected to a cultivating device 19 having a cultivating claw 18 so that it can be moved up and down, and a lift that moves up and down by a hydraulic cylinder. The arm 2 and the left and right lower links 16 are connected by a lift rod 20 so that the tiller 19 can be moved up and down. The power take-off shaft PTO at the rear end of the vehicle body 6 is interlocked to rotate the tilling pawl 18.

At the rear end of the cultivating cover 21 of the cultivating device 19, there is provided a leveling plate 23 which vertically rotates around a hinge 22, and the spring 2
It is configured so that it is elastically blasted downward at 4 and the soil surface is leveled at the lower edge. The depth sensor 5 is composed of a potentiometer or the like, is provided in the hinge 22, and can detect the vertical rotation angle of the flat plate 23 and input it to the controller on the vehicle body 6 side.

The steering brake control device has a change-over switch 2 on the input side of a controller 25 having a microcomputer for switching between automatic and manual steering brake control.
6, a steering sensor 27 for detecting the turning angle of the steering wheel 1, a lift arm sensor 28 for detecting the angle of the lift arm 2 ascending / descending, a depth sensor 5 for detecting the tilling depth of the tiller 19, and the tilling depth thereof. It has a working depth setting device 30 and the like.

On the output side of the controller 25, a raising solenoid valve 31 for raising and lowering the lift arm 2 is provided.
And the lowering solenoid valve 32, the left steering brake solenoid valve 33 and the right steering brake solenoid valve 34 for braking the hydraulic cylinders 15 of the left and right steering brakes 4, and the front wheels 7 with respect to the rear wheels 3. 4WD clutch solenoid valve 35 and double speed 4WD for switching between double speed 4WD that shifts to double speed and normal constant speed 4WD
It has a clutch solenoid valve 36 and the like.

During the plowing work, the plowing device 19 is lowered to the plowing depth position set by the plowing depth setting device 30, and the plowing with the plowing pawl 18 is performed. When the working depth changes, the flat plate 23 moves up and down, so the detection value of the depth sensor 5 changes, and the detection value of the depth sensor 5 changes.
Is compared with the set value by the controller 25,
Up or down solenoid valves 31, 32 are output,
The tiller 19 is raised or lowered by raising and lowering the lift arm 2, and the tilling depth control is performed along the set depth.

Automatic (lift) steering braking control (FIG. 3) is performed by switching the changeover switch 26 to the automatic mode side. When the steering wheel 1 is steered to make a turn at the edge of the ridge, the steering sensor 27 detects the steering angle of the steering wheel 1,
The lift arm 2 is raised by the output of the raising solenoid valve 31, and the tiller 19 is levitated from the tilling depth position.

When the tiller 19 is raised and the tiller 18 is near the soil surface, the flat plate 23 reaches the lower limit position,
The depth sensor 5 detects this and inputs it to the controller 25. By inputting the lower limit position of the depth sensor 5, the steering brake solenoid valve 33 or 34 on the left and right steering sides of the steering handle 1 is output.
As a result, the steering side hydraulic cylinder 15 is actuated, the brake arm 12 is hydraulically rotated, and either the left or right steering brake 4 is braked, and the steering brake 4 works to rotate the rear wheel 3 on the turning side. Is stopped and a sharp turn is made.

When performing a double-speed turn during such a steering turn, the double-speed mode is set in advance, and the double-speed 4WD clutch solenoid valve 36 outputs the double-speed from the engaged state of the 4WD clutch during normal work. By switching to the engagement of the 4WD clutch, the front wheels 7 are speeded up to about twice the speed of the rear wheels 3 so that turning can be performed quickly and easily.

According to the detection value of the lift arm sensor 28 in the above example, the steering brake 4 is braked when the lift arm is at a certain height or higher and the tiller 18 is above the soil surface. It may be configured to. In this case, the detection of the tilling depth sensor 5 does not have to be the lowest limit position.
Further, it is also possible to set a fixed time for starting the output of the steering brake 4 so that the steering brake 4 works even if the depth sensor 5 or the lift arm sensor 28 is not normal after a certain time has elapsed.

When the changeover switch 26 is switched to the manual mode, the steering brake 4 can be braked via the brake arm 12 by stepping on the brake petal 13, but as shown in FIG. Petal 1
3 is provided with a petal sensor 41 for detecting the depression of the pedal 3, and by detecting the brake petal 13 of the petal sensor 41, the left or right steering brake solenoid valves 33, 34 are operated so as to operate the hydraulic cylinder 15, and the braking force is increased. You may help the pedal to reduce the pedaling force.

In FIG. 6, a point different from the above example is that a link cylinder 41 for expanding and contracting between the rear ends of the lower link 16 and the top link 17 is provided, and the link cylinder 41 is shortened during the automatic steering brake control. Then, the cultivating device 19 is controlled to rise rapidly and float above the soil surface. Further, the link cylinder 41 is connected to the left and right lower links 1.
6 is provided separately for each 6, and the link cylinder 41 on the outside of the steering turn of the steering handle 1 is shortened, and the tiller 19 is tilted so that the outside of the turn floats.
Do not roughen the adjacent plowing soil surface. In this case, the rolling cylinder for rolling control may also be used to control the tiller 19 so that it is tilted to the left and right or horizontally.

[Brief description of drawings]

FIG. 1 is a side view.

FIG. 2 is a block diagram of steering brake control.

FIG. 3 is a flowchart thereof.

FIG. 4 is an enlarged side view of a steering brake operation mechanism section.

FIG. 5 is a side view showing another embodiment.

FIG. 6 is a side view of a working machine section showing another embodiment.

[Explanation of symbols]

 1 Steering handle 2 Lift arm 3 Rear wheel 4 Steering brake 5 Depth sensor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinji Otake 1st Hachikura, Tobe-cho, Iyo-gun, Ehime Prefecture

Claims (1)

[Claims] 1. A work of a working machine in a tractor which raises a lift arm 2 for raising and lowering a working machine by a steering angle of a steering handle 1 and turns a steering brake 4 of a rear wheel 3 in a steering direction. A steering brake control device, wherein the steering brake 4 is braked by detecting a reference height near the soil surface of a depth sensor 5 that detects a depth.