JP2000062626A - Steering device for tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate the steering wheel with front/rear nearly same diameter to a steering direction surely and accurately, even in the running of a soft muddy land in which the wheel is easy to drive. SOLUTION: Knuckle arms 21, 48 are provided on the lowerside of an arm main body and steering arms 7, 46 are provided on the upperside of the arm main body and right/left knuckle arms 20, 21 provided on both sides of front axle housing 1 and right/left knuckle arms 47, 48 provided on both sides of a rear axle housing 40 are connected in right/left by front/rear tie rods 19, 52 respectively and further, the ends and machine body of a steering arm provided on oneside of the front axle housing and a steering arm provided on oneside of the rear axle housing are connected interlockingly by an steering actuator respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering device for a tractor, and relates to a structure for reliably and accurately manipulating steering wheels having substantially the same diameter in the front and rear directions.

[0002]

2. Description of the Related Art As a mode for steering a steering wheel by operating a steering handle of a tractor, there is a steering hydraulic circuit having an orbit roll, a steering cylinder, and the like. However, when trying to operate a steered wheel of approximately the same diameter in the front and rear in the steering direction with certainty and accuracy, the position of the steering actuator attachment part or the tie rod attachment part that links the left and right wheels in an interlocking manner makes it possible for the wheel to slip easily. In the case of steering while driving on the ground, there was a problem that the steering links were bent around the steering shaft housing and the steering could not be accurately transmitted.

[0003]

According to the present invention, front and rear axle housings 1 and 40 are horizontally installed side by side in front and rear portions of a vehicle body, and a vertical steering shaft 2 is provided in each of the front and rear axle housings 1 and 40. Steering shaft housing 1 before or after
Steering shaft housing 1 before or after mounting 6, 42
Steering shafts 2 and 6 are provided at the lower ends thereof with final cases 5 and 43 for axially mounting front and rear wheels 3 and 41, and at the upper end thereof with a support cap 9 having a support arm 8 projecting laterally. It is mounted rotatably on the center, and at least one of the left and right upper parts of the final case 5 and 43 and the support arm 8 on the upper part of the steering shaft housing 16 and 42 is vertically connected via the arm bodies 17 and 45. The knuckle arms 20, 4 are provided below the arm bodies 17, 45.
7, the steering arm 7,
46 are provided between the left and right knuckle arms 21 and 20 provided on both sides of the front axle housing 1 and the left and right knuckle arms 48 provided on both sides of the rear axle housing 40.
Left and right tie rods 19 and 52 are connected to each other between the left and right parts 47, and a steering arm 7 provided on one side of the front axle housing 1 and a steering arm provided on one side of the rear axle housing 40. A steering device for a tractor, characterized in that the respective ends of the vehicle and the vehicle body are interlockingly connected by a steering actuator, and, as an additional configuration, a front tie rod 19 for connecting the left and right knuckle arms 21, 20 at the front part. In parallel with the front of the front axle housing 1 in a plan view and in the vicinity of the lower edge of the front axle housing 1 in a side view, and the rear left and right knuckle arms 48, 47.
A rear tie rod 52 that connects the two is parallel to the rear of the rear axle housing 40 in a plan view and is positioned near a lower edge of the rear axle housing 40 in a side view, and a steering actuator that steers the front and rear wheels 3, 41 is further provided. This is a steering device for a tractor with a configuration added to one side of the machine body.

[0004]

According to the invention described in the first item, the steering arm 7 and the knuckle arm 20 are vertically moved to the arm bodies 17 and 45 provided on at least one side of the front and rear axle housings 1 and 40, respectively. The front tie rod 19 is provided between the left and right knuckle arms 21 and 20 at the front.
The left and right knuckle arms 48, 47 are connected left and right by the rear tie rod 52,
The positions of the steering actuators and the tie rods of the wheels 3 and 41 having substantially the same shape in the front and rear can be separated vertically in the vicinity of the front and rear axle housings 1 and 40, and there is no fear that both members interfere with each other by the steering operation. .

Further, in the invention described in the second item, the front tie rod 1 for connecting the left and right knuckle arms 21 and 20 at the front portion.
9 in parallel with the front of the front axle housing 1 in a plan view, positioned near the lower edge of the front axle housing 1 in a side view, and a rear tie rod 52 connecting the rear left and right knuckle arms 48, 47 The rear axle housing 40 is arranged in parallel with the rear of the rear axle housing 40 in a side view, and is positioned near the lower edge of the rear axle housing 40 in a side view. Further, steering actuators for steering the front and rear wheels 3 and 41 are arranged on one side of the machine body. Therefore, the positions of the front and rear tie rods 19 and 52 are raised to the vicinity of the front and rear axle housings 1 and 40 which are provided at positions higher than the front and rear axles of the front and rear wheels 3 and 41, and the tie rods 19 and 52 contact the crop during traveling. In addition, the steering actuators can be easily gathered on one side of the machine body. This is easy to inspect because the steering actuators are installed at many places.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the illustrated example, the steering of the front wheels 3 will be described as an example. A front axle bracket 12 is connected to a front end portion of a vertical frame 11 of the vehicle body, and a sensor pivot 15 between a front pivot metal 13 and a rear mission case 14 is vertically arranged below the front axle bracket 12 as a center. A swingable front axle housing 1 is mounted.

The front axle housing 1 is detachably provided with steering shaft housings 16 in which vertical steering shafts 2 are housed at both left and right ends, and a final case 5 is provided at a lower end portion of the steering shaft housing 16. It is mounted so that it can be turned around the steering shaft 2. A front axle 4 is mounted on the final case 5 to mount the front wheel 3 on the outside. Further, the steering arm 7 attached to at least one of the final case 5 is projected in the front-rear direction from the intermediate portion of the arm body 17 along the outside of the steering shaft housing 16. The upper end of the arm body 17 is attached by a bolt 68 to a support arm 8 projecting toward the extension line of the axis of the steering shaft 2, which is the center of the steering shaft housing 16. Further, a support cap 9 is integrally formed on the lower side of the support arm 8 so as to project downward.

In the steering shaft housing 16, a vertical steering shaft 2 is pivotally supported, and a shaft hole 18 coaxial with the steering shaft 2 is formed at the upper end of the steering shaft housing 18. The support cap 9 is rotatably fitted therein. As a result, the final case 5, together with the steering arms 7 and the like, can be steered about the support cap 9 as a center. Knuckle arms 20 and 21 for connecting the tie rods 19 are attached to the left and right final cases 5, and these knuckle arms 20 and 21 are attached so as to be sandwiched between the arm body 17 and the final case 5. . Steering arms 7 may be formed on the left and right arm bodies 17, and the steering cylinder 6 may be connected to the left or right arm body 17 according to the steering mode. The steering arm 7 may be formed only on the arm body 17. Further, the arm body 17 may be integrally formed with the steering arm 7, the knuckle arms 20, 21 and the like.

The steering sensor 10 is composed of a potentiometer, and the sensor shaft 22 is aligned with the axis of the steering shaft 2 so as to be positioned on the support cap 9 and fixed laterally protruding from the sensor 10. Tighten the arm 23 to the upper end of the steering shaft housing 16 with the bolt 24,
A sensor arm 71 protruding laterally from the sensor shaft 22.
Is fixed to the upper end of the arm body 17 with a fixing pin 25. In this way, the fixed arm 23 rotates the sensor shaft 22 together with the arm body 17 and the sensor arm 71 on the steering arm 7 side with respect to the steering sensor 10 fixed on the steering shaft housing 16 side. Thus, the steering angle can be detected.

The steering cylinder 6 is a double-acting type, and is a single rod type in which the piston rod 26 projects only at one end side. The steering cylinder 6 side is attached to the lateral frame 27 of the front axle bracket 12 by a bracket 28, or , The front end of the piston rod 26 is connected to the steering arm 7 and the steering cylinder 6 is hydraulically expanded and contracted to rotate the steering arm 7 to steer the front wheels 3. Is.

A muffler 29 is provided at the front end of the front axle bracket 12 to guide the exhaust gas discharged from the engine E mounted on the upper part of the front axle bracket 12, and a muffler cover 30 for covering the outer peripheral portion of the muffler 29 and a rear front part. The steering cylinder 6 is located between the axle housing 1 and the axle housing 1 so that the steering cylinder 6 does not project downward from the lower limit positions of the muffler cover 30 and the front axle housing 1.

A bonnet 31 covering the engine E on the front end of the vertical frame 11 and a steering post 32 on the rear end.
Is provided, and the orbit roll 35 is attached to the steering shaft 34 rotated by the steering handle 33 at the upper end.
Is provided and hydraulic pressure is sent to the steering cylinder 6 via the steering hydraulic circuit 36 by the orbit roll 35 to control the steering.

An engine E is provided at the front end of the vertical frame 11.
From the belt 37, a transmission case 14 is provided for transmitting a transmission gear such as a transmission, a traveling shaft 38, a power output interlocking shaft 39 and the like in the front-rear direction.
The front end of 8 is interlocked with a differential gear installed in the center of the front axle housing 1, and is interlocked with the steering shaft 2 via the axles in the left and right front axle housings 1 from this differential gear. The steering axle 2 and the front axle 4 are interlocked.

The rear axle housing 40 provided at the rear portion of the vertical frame 11 has substantially the same structure as the front axle housing 1, and rear wheels 41 on both left and right sides are steerably provided. Therefore, the steering shaft housing 4 at the left and right ends of the rear axle housing 40 of the rear wheel 41 is
2, the structure of the steering shaft, the final case 43, the rear axle 44, and the like, and the arm body 45 related thereto, the steering arm 46 integrally formed with the arm body 45, and the upper end portion of the arm body 45. The supporting arm to be attached, the supporting cap, and related structures such as the knuckle arms 47 and 48 to be attached to the lower end are substantially the same.

However, while the steering arm 46 projects forward, the knuckle arms 47 and 48 project rearward. The arm body 45, the arm body 45, and the If the knuckle arms 47 and 48 are formed in the same form as the knuckle arms 20 and 21,
If the knuckle arms 20 and 21 are used by shifting left and right, they can be used as the knuckle arms 47 and 48 for the rear wheel 41.

Further, the steering cylinder 49 may be of the same standard as the steering cylinder 6 for the front wheels 3, and the steering cylinder 49 may be attached to the horizontal frame 50 connecting the left and right vertical frames 11. Mount the tip end with the bracket 51.
Further, the tip end of the piston rod 52 is the steering arm 4
Connect to 6. The left and right knuckle arms 47 are connected by a tie rod 52.

Further, when a steering sensor is required for steering the rear wheels 41, in the same manner as in the case of steering the front wheels 3, the steering sensor is mounted above the steering shaft and the support cap on the steering arm 46 side. It may be located and mounted similarly to the steering sensor 10. 69 is a floor mounting bracket and 70 is a floor. When the treads of the front wheels 3, the rear wheels 41, etc. are changed, the front axle housing 1 is mounted on both ends of the steering shaft housing 16 and the rear axle housing 40 on both ends thereof. A spacer case having an appropriate length is interposed between the steering shaft housing 42 and the steering shaft housing 42 so as to be changed and adjusted. In this case, the axles in the axle housings 1 and 40 are changed in length and length, the tie rods 19 and 52 are also changed in length and length, and the mounting positions of the steering cylinders 6 and 49 are also changed. In order to change the mounting positions of the steering cylinders 6 and 49, if mounting holes 53 and the like for mounting the brackets 28 and 51 to the horizontal frames 27 and 50 are provided in advance, these brackets 28 and 51, etc. Changing clothes can be simplified. The mounting hole 53 has a tapered shape, and the mounting pin 54 also has a tapered shape.
By performing the positioning accurately, the error of the steering sensor 10 and the like is reduced and the accurate steering can be maintained.

The differential gear in the rear axle housing 40 is interlocked with the traveling shaft 38 of the transmission case 14 by the interlocking shaft 55 to drive the rear wheel 41. The power take-out interlocking shaft 39 is interlocked by the interlocking shaft 56 with a transmission device in the power take-out transmission case 58 located below the cockpit 57, and the power take-out shaft 59 is interlocked with the transmission device so that the power transmission can be changed. Also, the rear axle housing 40
A lift arm 60 is movably connected to the vertical arm 72, and can be moved up and down by hydraulic pressure from a hydraulic circuit 62 of a lift cylinder 61 provided along the rear end of the vertical frame 11, so that a working device connected to the rear end can be moved up and down. it can. 63 is a hydraulic pump of the hydraulic circuit 62, and 64 is a lift control valve.

The left and right knuckle arms 47 and 48 for steering the rear wheel 41 are projected rearward, and a lift arm 60 is provided.
At the lowered position, is set so as not to get in the way at this lower limit position. Further, in the steering cylinders 6, 49 and the like, a connecting member 66 for connecting the horizontal frames 11 and 50 of the cylinders is screwed into the steering cylinder 6 so that the expansion and contraction can be adjusted. The lengths of the steering cylinders 6 and 49 can be finely adjusted.

In the steering hydraulic circuit 36, the orbit roll 35 is supplied with hydraulic pressure by a hydraulic pump 65, and the front wheel steering valve A and the rear wheel steering valve B serve as solenoid valves from a controller having a microcomputer. It is configured to be output. This controller includes the steering sensor 10 for detecting the steering angle of the steering wheel 33 as well as the steering sensor 10 described above.
Further, a steering mode switch or the like for selecting and designing a steering mode is provided and input, and when the steering sensor detects a predetermined turning angle of the steering handle 33 in accordance with the designated steering mode, the hydraulic pressure passing through the orbit roll 35 is predetermined. Is sent to the steering cylinder 6 or 49 for steering. The steering angles of the wheels 3 and 41 are detected by the steering sensor 10 and input to the controller to feedback control the steering valves A and B to perform a predetermined steering operation by the steering wheel 33. is there.

As the steering mode, there are modes in which only the front wheels 3 are steered, only the rear wheels 41 are steered, and the front wheels 3 and the rear wheels 41 are interlocked.

[Brief description of drawings]

The figure shows an embodiment of the invention.

FIG. 1 is a partially cutaway front view of a steering shaft housing portion of a front wheel.

FIG. 2 is a plan view of FIG.

FIG. 3 is a plan view of a steering device portion of a front wheel.

FIG. 4 is a side view of a portion of FIG.

FIG. 5 is a plan view of a steering device portion of a rear wheel.

6 is a side view of a portion of FIG.

FIG. 7 is a side view of the entire tractor.

FIG. 8 is a plan view of a part of the tractor frame.

9 is a side view of FIG.

FIG. 10 is a hydraulic circuit diagram.

[Explanation of symbols]

1 (front) axle housing 2 Steering axis 3 (front) wheel 4 axles 5 (front) Final case 6 (Front) Steering cylinder 7 (front) Steering arm 8 Support arm 9 Support cap 16 (Front) Steering shaft housing 17 (Front) Arm body 19 (front) Tie rod 20 (Front) (Right) Knuckle arm 21 (Front) (Left) Knuckle arm 40 (rear) axle housing 41 (rear) wheel 42 (Rear) Steering shaft housing 43 (later) Final Case 45 (rear) arm body 46 (Rear) Steering arm 47 (Rear) (Right) Knuckle arm 48 (rear) (left) knuckle arm 49 (Rear) Steering cylinder 52 (Rear) Tie rod

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Fumio Kuroiwa             No. 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture             Technology Department Co., Ltd. (72) Inventor Minoru Matsuoka             No. 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture             Technology Department Co., Ltd. (72) Inventor Yasuhiro Miyauchi             No. 1 Yakura, Tobe-cho, Iyo-gun, Ehime Prefecture             Technology Department Co., Ltd.

Claims (2)

[Claims] 1. A front or rear steering shaft in which front and rear axle housings 1 and 40 are laterally installed side by side on the front and rear portions of a vehicle body, and vertical steering shafts 2 are provided in the front and rear axle housings 1 and 40, respectively. The housings 16 and 42 are attached, and the front and rear wheels 3 and 4 are attached to the lower end portions of the steering shaft housings 16 and 42 before and after this.
A support cap 9 having final cases 5 and 43 axially mounting 41, and a support arm 8 projecting laterally at the upper end.
The steering shaft is mounted on the steering shaft 2 so that the steering shaft is rotatable. Further, at least one of the left and right final cases 5 and 43 and the steering shaft housings 16 and 42 is armed between the support arms 8. The knuckle arms 20 and 47 are provided below the arm bodies 17 and 45, and the steering arms 7 and 46 are provided above the arm bodies 17 and 45. , These left and right knuckle arms 2 provided on both sides of the front axle housing 1
1 and 20 and left and right knuckle arms 48 and 47 provided on both sides of the rear axle housing 40 are respectively connected left and right with front and rear tie rods 19 and 52, and further provided on one side of the front axle housing 1. A steering device for a tractor, characterized in that the respective ends of the steering arm 7 and a steering arm 46 provided on one side of the rear axle housing 40 and the body are interlockingly connected by a steering actuator. 2. A front tie rod 19 connecting the front left and right knuckle arms 21, 20 is arranged in parallel with the front of the front axle housing 1 in a plan view, and is positioned near a lower edge of the front axle housing 1 in a side view. Also, a rear tie rod 52 that connects the left and right knuckle arms 48, 47 to each other
Is parallel to the rear of the rear axle housing 40 in a plan view, is positioned near the lower edge of the rear axle housing 40 in a side view, and a steering actuator that steers the front and rear wheels 3 and 41 is arranged on one side of the machine body. The steering device for a tractor according to claim 1, wherein: