JPH10211883A - Steering system of farm working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly perform a rotational operation on a steering wheel in time of car turning in a laborsaving manner by constituting the ratio of a wheel steering quantity to a rotational quantity in the steering wheel so as to grow larger in the time of largely rotatively operating the steering wheel than in time of rotatively operating it small. SOLUTION: An intermediate shaft 9 and an arm shaft 12 are supported in parallel with a shaft transmitting a steering wheel rotation in a gearbox to be installed in front of a traveling car body for a nursery bed planter or the like. An elliptical driven gear 13 being locked to the arm shaft 12 is engaged with an elliptical driving gear 11 to be locked to an intermediate shaft adjacent to this intermediate shaft 9. Then a symmetrical pair of tie rods 18 are connected to an arm 14 clamped tight to a lower end of the arm shaft 12, and thereby a symmetrical pair of wheels are steered by a rotation of the arm 14, but the ratio of a wheel steering quantity to a rotational quantity of the steering wheel in time of car turning is made so as to be larger in time of largely rotatively operating the steering wheel than in time of rotatively operating it small.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a working vehicle such as a traveling body for a seedling plant, for example, in which a steering wheel is turned to steer a pair of left and right wheels. Belongs to the technical field of steering devices.

[0002]

2. Description of the Related Art In a conventional steering apparatus for a working vehicle, the ratio of the amount of steering of a wheel to the amount of rotation of a steering wheel is as follows.
No matter how the steering wheel is turned, it will be constant.

[0003]

When performing work such as agricultural work on a work vehicle, the work is often performed by reciprocating the work vehicle, and therefore, the operation of turning the vehicle is frequently performed. And, since the conventional working vehicle is provided with the steering device as described above, when turning the vehicle, the steering wheel must be turned from the position where the vehicle is traveling straight ahead. did not become. Therefore, in the conventional working vehicle, when the turning is frequently performed, the labor of the turning operation of the steering wheel is large, and it is also difficult to quickly turn the vehicle. Was.

[0004] If the amount of steering of the wheels relative to the amount of turning operation of the steering wheel is increased, the amount of turning operation of the steering wheel at the time of rapid turning of the vehicle is reduced. When the wheel is turned slightly from the position where the vehicle is traveling straight, there is a problem that the wheel is largely steered by a small number of turning operations of the steering wheel, and it is difficult to make a fine course correction.

Therefore, the present invention relates to a work vehicle,
It is an object of the present invention to make it easy to perform a subtle course correction when the vehicle is going straight, as in the related art, and to quickly perform a turning operation of the steering wheel when the vehicle is turning with little labor.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention relates to a power steering apparatus for a working vehicle having a structure in which a pair of left and right wheels 16 are steered by rotating a steering wheel 5. When the ratio of the steering amount of the wheel 16 to the rotation amount of the steering wheel 5 is larger than the position where the vehicle is traveling straight, the steering wheel 5 moves the vehicle. A steering device for a working vehicle, characterized in that the steering device is configured to be smaller than the position when the vehicle is running straight and larger than the one when the turning operation is performed.

[0007]

The present invention is directed to a steering apparatus for a working vehicle having the above-mentioned structure. Therefore, the steering wheel 5 is operated by turning the steering wheel 5 from a position where the vehicle is traveling straight, so that the vehicle is turned. When turning the vehicle, the steering wheel 5 can be operated with a smaller amount of turning operation than before, and the steering wheel 5 is turned slightly from the position where the vehicle is moving straight to correct the course when the vehicle goes straight. In some cases, the amount of steering of the wheel with respect to the amount of turning operation of the steering wheel can be the same as in the related art. In addition, since the wheels 16 can be steered as described above, the force required for the turning operation of the steering wheel 5 differs between when the vehicle is turned and when the course is corrected when the vehicle is traveling straight. The fact that the power steering device is provided makes it possible to operate the vehicle with the same operation force both at the time of turning and at the time of correcting the course, thereby improving the operational feeling.

Accordingly, the steering apparatus for a working vehicle according to the present invention can easily perform a fine course correction when the vehicle is going straight, as in the prior art, and can quickly turn the steering wheel when turning the vehicle with little labor. The operation can be performed with the same operation force both at the time of turning and at the time of course correction, and the operational feeling is improved.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described in detail below. As shown in FIG. 1, a gear box 1 is provided at the front of a working vehicle (the figure is a traveling body for a seedling planter), and a shaft 2 shown in FIG. Have been. This shaft 2 is connected by a coupling 3 to a torque generator 4 thereon, which operates with the assistance of pressure oil as the steering wheel 5 further rotates. It is made like. Before or after the torque generator 4, a column (support) 6 extending upward from the gear box 1 is provided, and the torque generator 4 is supported. In this column 6,
As shown in FIG. 2, the horizontal lever 20 is provided in a cross shape, and the clutch pedal 21 and the brake pedal 22 can be mounted. The steering handle 5 is configured as a tilt type that rotates back and forth. The torque generator 4 shown in the figure is a power steering device in which a rack 7 arranged in a horizontal cross direction is pushed right and left by hydraulic pressure with the operation of a steering wheel 5 to rotate a pinion (not shown). Make up.

The lower end of the shaft 2 is cut into a gear 8 (FIG. 3). An intermediate shaft 9 is supported in parallel with the shaft 2, and an intermediate gear 10 fixed to the intermediate shaft 9 meshes with the gear 8 so that the rotation of the shaft 2 is reduced and transmitted to the intermediate shaft 9. This intermediate shaft 10 has an elliptical driving gear 11
Has been fixed. An arm shaft 12 is supported on the gear box 1 in parallel with the shaft 2, and a driven gear 13 fixed to the arm shaft 12 is formed in an elliptical shape and meshes with the main driving gear 11. The lower end of the arm shaft 12 is connected to the gear box 1.
Arm 14 is fixed to the end of the arm.

A pair of left and right upper cases 1 are provided at the rear of the gear box 1.
A lower case 17 supporting a wheel 16 is provided below the upper case 14 so as to rotate about a vertical axis. When both ends of a pair of left and right tie rods 18 are connected to the arm 14 and the knuckle arm 19 extending from the lower case 17, when the arm 14 rotates, the lower case 17 rotates around a vertical axis. Rotating, a pair of left and right wheels 1
6 is steered. And the driving gear 1
1 and the driven gear 13 are arranged such that when the left and right wheels 16 advance the vehicle straight, the short-diameter position of the main driving gear 11 meshes with the long-diameter position of the driven gear 13, and the lower case 17 rotates. Then, the meshing position of the driving gear 11 moves to the longer diameter side of the ellipse as the turning angle of the wheel 16 increases.

Therefore, the steering apparatus for a working vehicle described above is
A pair of left and right wheels 1 is operated by rotating the steering wheel 5.
6, the power steering apparatus is provided, and the ratio of the amount of steering of the wheels 16 to the amount of rotation of the steering wheel 5 is determined based on the position of the steering wheel 5 when the vehicle is traveling straight. The steering wheel 5 should be used when performing a large turning operation.
The steering wheel 5 is turned from the position where the vehicle is traveling straight, and is larger than the position when the vehicle is traveling straight, so that the vehicle is turned. When the steering wheel 5 is turned, the turning operation amount of the steering wheel 5 may be smaller than before, and when the steering wheel 5 is turned slightly from the position where the vehicle is moving straight to correct the course when the vehicle goes straight, The amount of steering of the wheel with respect to the amount of turning operation of the steering wheel can be the same as in the related art. In addition, since the wheels 16 can be steered as described above, the force required for the turning operation of the steering wheel 5 differs between when the vehicle is turned and when the course is corrected when the vehicle is traveling straight. Come
By providing the power steering device, the user can operate the vehicle with the same operation force both at the time of turning and at the time of correcting the course, thereby improving the operational feeling.

Therefore, the steering apparatus for a working vehicle according to the present invention can easily perform a fine course correction when the vehicle goes straight ahead as in the prior art, and can quickly turn the steering wheel when turning the vehicle with little labor. The operation can be performed with the same operation force both at the time of turning and at the time of course correction, and the operational feeling is improved.

[Brief description of the drawings]

FIG. 1 is a side view of a working vehicle.

FIG. 2 is a front view of a part of the steering device;

FIG. 3 is a side view of a part of the steering device;

FIG. 4 is a plan view of a part of the steering device;

[Explanation of symbols]

 4: Torque generator 5: Steering wheel 16: Wheel

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Rihiki Seike, 1-Yakura, Hachikura, Tobe-cho, Iyo-gun, Ehime Prefecture, Iseki Agricultural Machinery Co., Ltd. Engineering Department

Claims (1)

[Claims] 1. A work vehicle having a structure in which a pair of left and right wheels 16 are steered by turning a steering wheel 5 and comprising a power steering device, and a steering amount of the wheels 16 with respect to a turning amount of the steering wheel 5. Is larger when the steering wheel 5 is turned from the position where the vehicle is moving straight, and when the steering wheel 5 is turned from the position when the vehicle is moving straight. A steering apparatus for a working vehicle, wherein the steering apparatus is configured to be larger.