JP2000247239A - Steering structure for working vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise in a cabin by constituting a steering system corresponding to medium and large working vehicles, even in a small working vehicle limited in space, and disposing a steering unit in a position inside an engine hood or the like, away from the cabin. SOLUTION: Support brackets 31, 32 for supporting steering shafts 22, 24 rotatably are arranged at two parts on the cabin side and engine 5 side. The support bracket 32 is fixedly mounted to one end of a mounting flange 5a of the engine 5, and bending angles θ1, θ2, θ3, θ4 at the respective connection parts of a plurality of rotatably connected steering shafts 21, 22, 23, 24 and a power steering unit 25 are formed to be almost the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering structure for a work vehicle applied to a tractor or the like, and more particularly to a steering shaft support structure.

[0002]

2. Description of the Related Art Conventionally, in a working vehicle such as a tractor, particularly a medium-sized or large-sized working vehicle, a steering wheel and a power steering unit are connected by a plurality of steering shafts forming a link, and the steering shaft is And a support bracket such as a pillow ball bracket capable of rotatably supporting the steering shaft. The support bracket was provided at one place on the front plate of the cabin. In addition, the power steering unit was disposed in the hood at a location away from the cabin. On the other hand, in a small work vehicle, since the space inside the hood in which the engine is stored is small, it is difficult to adopt a configuration similar to that of a medium or large work vehicle. It was located near the cabin, such as on the housing.

[0003]

However, as described above,
If the power steering unit is arranged near the cabin, the operating noise of the power steering unit enters the cabin, and the noise in the cabin increases. Therefore, in the present invention, even in a small work vehicle having a limited space, the power steering unit is disposed at a position away from the cabin such as in a hood or the like, with the steering system being configured in accordance with a medium or large work vehicle. , To reduce noise in the cabin.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, according to claim 1, in a steering structure of a work vehicle in which a steering wheel and a power steering unit are connected by a plurality of steering shafts forming a link, a support bracket for rotatably supporting the steering shaft is provided. It was arranged at two places on the cabin side and the engine side.

According to a second aspect of the present invention, in a steering structure of a working vehicle in which a steering wheel and a power steering unit are connected by a plurality of steering shafts forming a link, a support for rotatably supporting the steering shaft is provided. The bracket was attached and fixed to one end of a mounting flange of the engine.

According to a third aspect of the present invention, in a steering structure of a working vehicle in which a steering wheel and a power steering unit are connected by a plurality of steering shafts constituting a link, the steering shafts are connected to each other so as to be rotatable. The bending angles at the connecting portions of the steering shaft and the power steering unit are substantially the same.

According to a fourth aspect of the present invention, in a steering structure of a working vehicle in which a steering wheel and a power steering unit are connected by a plurality of steering shafts forming a link, a support for rotatably supporting the steering shaft is provided. The bracket and the power steering unit were attached and fixed via a vibration isolating member.

[0008]

Next, an embodiment of the present invention will be described. FIG. 1 is an overall side view showing a tractor as a working vehicle having a steering structure of the present invention, FIG. 2 is a side view showing a steering structure, FIG. 3 is a rear view thereof, and FIG. is there.

First, the overall configuration of a tractor which is an embodiment of the working vehicle according to the present invention will be described with reference to FIG. A bonnet 6 is disposed at the front of a body that suspends front and rear wheels 1 and 2 at the front and rear. The front wheel 1 is supported by a front axle bracket 3 fixed to the body. The hood 6 contains an engine 5 and the like. A cabin 12 is provided behind the hood 6, a dashboard 18, a steering wheel 10, and the like are provided at a front portion in the cabin 12, and a seat 11 is provided behind the steering wheel 10.

A clutch housing 8 is connected to the rear of the engine 5 and a transmission case 9 is connected to the rear of the clutch housing 8. Power from the engine 5 is transmitted to the rear wheels 2 for driving. The driving force of the engine 5 is transmitted to a power take-off shaft projecting from the rear end of the transmission case 9 so as to be able to drive a working machine connected to the rear end of the machine body.

Next, the steering structure of the tractor will be described. As shown in FIGS. 2 and 3, in the cabin 12, a steering column 17 projects rearward and upward from a dashboard 18, and the steering column 17 is covered with a column cover 19. The steering wheel 10 is disposed at an upper end of the steering column 17. Steering column 17
Is equipped with a first steering shaft 21, and the first steering shaft 21 is rotatably supported on the steering column 17 by a bearing 17a.
The steering wheel 10 is attached to an upper end of the first steering shaft 21 and is configured to be rotatable integrally with the first steering shaft 21.

An upper end of a second steering shaft 22 is connected to a lower end of the first steering shaft 21,
An upper end of a third steering shaft 23 is connected to a lower end of the second steering shaft 22, and an upper end of a fourth steering shaft 24 is connected to a lower end of the third steering shaft 23. A power steering unit 25 is connected to a lower end of the power steering unit. The first steering shaft 21 and the second steering shaft 22, the second steering shaft 22 and the third steering shaft 23, the third steering shaft 23 and the fourth steering shaft 24, and the fourth steering shaft 24 and the power steering unit 25 , And are rotatably connected to each other by a cross joint or the like. That is, the steering wheel 10 and the power steering unit 25 are connected by the first, second, third, and fourth steering shafts 21, 22, 23, and 24 forming a link.

The first steering shaft 21 and the second steering shaft 22 are disposed substantially at the center in the left and right directions and extend forward and downward from the steering wheel 10 side. The fourth steering shaft 24 is disposed on one of the left and right sides of the engine 5. The third steering shaft 23 is also extended forward and downward, and connects the second steering shaft 22 and the fourth steering shaft 24 from substantially the center in the right and left direction to one of the left and right sides of the engine 5 while extending in the forward and downward direction. are doing.

Each of the steering shafts 21 and 22
・ 23 ・ 24 and power steering unit 25
The first steering shaft 21 and the second steering shaft 22 are connected to each other with a certain bend angle.
, The angle θ2 between the second steering shaft 22 and the third steering shaft 23, the angle θ3 between the third steering shaft 23 and the fourth steering shaft 24, and the power steering with the fourth steering shaft 24. The bend angle θ4 with the unit 25 is configured to be substantially the same. 2 and 3, each bending angle θ is viewed from the side or the rear.
1, θ2, θ3, and θ4 are displayed.
.Theta.2, .theta.3, and .theta.4 do not indicate bending angles in a side view or a rear view.
3 shows the actual angle of bend between 2.23.24 and the power steering unit 25.

When the steering wheel 10 is rotated, the rotation of each steering shaft 2 is controlled.
1, 22, 23, and 24 to the power steering unit 25, and the power steering unit 2
5 is operated. The power steering unit 25 is connected to the power cylinder 26 by a hydraulic pipe 33.
The operation of 5 causes the power cylinder 26 to expand and contract, whereby the steering operation of the front wheel 1 is performed. Also,
The power steering unit 25 is disposed in the hood 6, for example, at the lower left and right sides of the engine 5, and is fixed to the front axle bracket 3.
5a.

The third steering shaft 23 is constructed by integrally connecting an upper shaft 23a and a lower shaft 23b. The third steering shaft 23
Upper shaft 23a and the second steering shaft 2
2, the first steering shaft 21 forms a cabin-side steering shaft, and the lower shaft 23b of the third steering shaft 23 and the fourth steering shaft 24 form an engine-side steering shaft.

The second steering shaft 22 is rotatably supported at an intermediate portion thereof by a first pillow ball bracket 31. The first pillow ball bracket 31 is attached to, for example, the dashboard 18 via a fixed bracket 31a. It is attached and fixed. The fourth steering shaft 24 is rotatably supported at an intermediate portion thereof by a second pillow ball bracket 32. The second pillow ball bracket 32 is connected to a mounting flange 5a of the engine 5 via a fixed bracket 32a. It is fixedly attached to the left or right end. That is, the second and fourth steering shafts 22 and 24 are rotatably supported by first and second pillow ball brackets 31 and 32 as support brackets, respectively. 32 are arranged at two locations, ie, the cabin-side steering shaft and the engine-side steering shaft.

As described above, the steering structure includes the steering wheel 10 and the power steering unit 2.
5 are connected by first, second, third, and fourth steering shafts 21, 22, 23, and 24 that form a link, and the second and fourth steering shafts 22 and 24 are rotatably supported. First and second pillow ball bracket 31
-By arranging the 32 at two locations of the cabin-side steering shaft and the engine-side steering shaft, the steering structure can be configured in a space-saving manner. Even in a small work vehicle, the power steering unit 25 can be removed from the cabin 12. The hood 6 away
It is possible to adopt a configuration similar to the steering structure of a medium-sized or large-sized work vehicle, such as disposing the power steering unit 25 in the cabin 12, preventing the operation sound of the power steering unit 25 from entering the cabin 12, and reducing the noise in the cabin 12. Reduction can be achieved. In addition, since the work can be performed without largely disassembling the mechanism when performing maintenance of the steering structure, the work efficiency can be improved and the work can be facilitated.

The second pillow ball bracket 32 on the engine side is mounted on the mounting flange 5a of the engine 5.
By attaching and fixing to the left end or right end of the
The fourth steering shaft 24 can be supported in a space-saving manner, and even in a small work vehicle, the steering of a medium or large work vehicle such as disposing the power steering unit 25 in the hood 6 away from the cabin 12 can be achieved. It is possible to adopt the same configuration as the structure, and it is possible to prevent the operation noise of the power steering unit 25 from entering the cabin and reduce the noise inside the cabin 12.

Each of the steering shafts 21 and 22
The power steering unit 25 is arranged in the bonnet 6 as described above by configuring the respective bending angles θ1, θ2, θ3, and θ4 of the connecting portions of the power steering unit 25 and the power steering unit 25 to be substantially the same. This configuration can be achieved without deteriorating the steering feeling of the steering wheel 10.
Further, the transmission loss of rotation from the steering wheel 10 to the power steering unit 25 can be reduced, and the mechanical efficiency of the steering structure can be improved.

The fixed bracket 31a attached to the dashboard 18 fixes the first pillow ball bracket 31 with bolts. The fixed bracket 32a for fixing the second pillow ball bracket 32 connects the power steering unit 25 to the mounting flange 5a. The fixing bracket 25a to be fixed is attached to the front axle bracket 3 by bolts, respectively. Next, a fixing structure / attachment structure of each fixing bracket 31a, 32a, 25a will be described. In FIG. 4,
For example, the fixing structure of the first pillow ball bracket 31 in the fixing bracket 31a is shown, and the fixing structure will be described below. The mounting structure of the fixing bracket 32a to the mounting flange 5a and the front axle bracket 3 of the fixing bracket 25a are described. The structure for attachment to the camera is similarly configured.

That is, a first vibration isolating member 51 and a second vibration isolating member 52 made of a flexible material such as rubber are provided at a fastening portion between the fixing bracket 31a and the first pillow ball bracket 31 by the bolt 53. And put them together. The first anti-vibration member 51 is formed in a substantially cylindrical shape, and an end of the bolt 53 on the head 53a side is extended in the radial direction. The second anti-vibration member 52 is formed in a substantially disk shape.
When the fixing bracket 31a and the first pillow ball bracket 31 are fastened by the bolt 53, the first pillow ball bracket 31 and the bolt 53
Between the screw portion 53b and the head 53a of the first vibration isolating member 5
1 intervenes, and the second vibration isolation member 52 intervenes between the first pillow ball bracket 31 and the fixed bracket 31a.

Thus, the first pillow ball bracket 31 and the bolt 53 and the first pillow ball bracket 3
1 does not directly contact the fixed bracket 31a,
Even when the vibration such as the vibration generated by the engine 5 is transmitted to the fixed bracket 31a, the vibration is absorbed by the first vibration isolating member 51 and the second vibration isolating member 52. Steering wheel 1
The transmission of vibration to zero can be prevented.

In the case of fastening as described above, the work procedure is as follows. First, the first vibration isolating member 51 is fitted to the bolt 53 and then the bolt 53 is connected to the first pillow ball bracket 3.
1 and then the second anti-vibration member 52 is fitted to the bolt 53 from the tip side, and the bolt 53 is fixed to the fixing bracket 31a.
It should be fastened to. As described above, the vibration isolating member is divided into the first vibration isolating member 51 and the second vibration isolating member 52 so as to improve workability. The same configuration can be adopted even if the vibration member 52 is integrally formed.

Also, when the fixing bracket 32a for fixing the second pillow ball bracket 32 is attached to the mounting flange 5a, or when the fixing bracket 25a for fixing the power steering unit 25 is attached to the front axle bracket 3, the fastening is performed as described above. The first vibration isolating member 51 and the second vibration isolating member 52
By interposing and fastening, vibration from the engine 5 and the like can be prevented from being transmitted to the steering wheel 10.

As described above, by supporting the components of the steering structure such as the second and fourth steering shafts 22 and 24 and the power steering unit in a vibration-proof manner, the vibration from the engine 5 and the like is transmitted to the steering wheel 10. Cabin 12
The interior noise can be reduced, and the operation feeling of the steering wheel 10 can be improved. Further, the first vibration isolating member 51 and the second vibration isolating member 52
Is simple in structure and does not require space, so that it can be easily configured even in a small work vehicle.

[0027]

As described above, the present invention has the following advantages. That is, since the support brackets for rotatably supporting the steering shaft are arranged at two locations on the cabin side and the engine side as described in claim 1, the steering structure can be configured in a space-saving manner and small-sized work can be performed. In a vehicle, it is possible to adopt a configuration similar to the steering structure of a medium-sized or large-sized work vehicle, such as disposing a power steering unit in a bonnet away from the cabin, and the operating noise of the power steering unit enters the cabin. This prevents noise in the cabin.
In addition, since the work can be performed without largely disassembling the mechanism when performing maintenance of the steering structure, the work efficiency can be improved and the work can be facilitated.

Further, since the support bracket for rotatably supporting the steering shaft is fixedly attached to one end of the mounting flange of the engine, the steering shaft can be supported in a small space. As a result, even in a small work vehicle, it is possible to adopt a configuration similar to the steering structure of a medium or large work vehicle, such as disposing the power steering unit in a bonnet away from the cabin, and the operating noise of the power steering unit Can be prevented from entering the cabin, and noise in the cabin can be reduced.

Further, the steering shaft is rotatably connected to each other and the angle of bend at each connecting portion of the steering shaft and the power steering unit is substantially the same. Even when the steering unit is disposed in the hood, the steering unit can be configured without deteriorating the steering feeling of the steering wheel. Further, the transmission loss of rotation from the steering wheel to the power steering unit can be reduced, and the mechanical efficiency of the steering structure can be improved.

Further, since the support bracket for rotatably supporting the steering shaft and the power steering unit are mounted and fixed via the vibration isolating member, vibration from the engine or the like is transmitted to the steering wheel. Can be prevented, the noise in the cabin can be reduced, and the operation feeling of the steering wheel can be improved. Further, since the vibration-proof support structure using the vibration-proof member has a simple structure and does not require a space, it can be easily configured even in a small work vehicle.

[Brief description of the drawings]

FIG. 1 is an overall side view showing a tractor as a working vehicle having a steering structure of the present invention.

FIG. 2 is a side view showing a steering structure.

FIG. 3 is a rear view of the same.

FIG. 4 is a side sectional view showing a vibration-proof support structure.

[Explanation of symbols]

 Reference Signs List 5 engine 5a mounting flange 6 bonnet 10 steering wheel 18 dashboard 21 first steering shaft 22 second steering shaft 23 third steering shaft 24 fourth steering shaft 25 power steering unit 25a fixing bracket 31 first pillow ball bracket 31a fixing bracket 32 Second pillow ball bracket 32a Fixed bracket 51 First vibration isolating member 52 Second vibration isolating member 53 Bolt

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[Procedure amendment]

[Submission date] June 23, 1999 (1999.6.2
3)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

Claims (4)

[Claims] In a steering structure of a working vehicle in which a steering wheel and a power steering unit are connected by a plurality of steering shafts forming a link, a support bracket for rotatably supporting the steering shaft is provided on a cabin side and on a cabin side. A steering structure for a working vehicle, wherein the steering structure is disposed at two positions on the engine side. 2. In a steering structure of a working vehicle in which a steering wheel and a power steering unit are connected by a plurality of steering shafts forming a link, a support bracket for rotatably supporting the steering shaft is mounted on an engine mounting. A steering structure for a working vehicle, wherein the steering structure is fixed to one end of a flange. 3. A steering structure for a working vehicle in which a steering wheel and a power steering unit are connected by a plurality of steering shafts forming a link, wherein the steering shafts are rotatably connected to each other. A steering structure for a working vehicle, wherein a bending angle at each connecting portion of the steering unit is substantially the same. 4. A support bracket for rotatably supporting a steering wheel in a steering structure of a working vehicle in which a steering wheel and a power steering unit are connected by a plurality of steering shafts forming a link, and a power steering unit. A steering structure for a working vehicle, wherein the steering wheel is mounted and fixed via an anti-vibration member.