JP2003205843A - Steering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems in a conventional steering device for a running vehicle wherein rust occurs due to rainwater entering the inside of a steering column and dew condensation inside the steering column, thereby shortening service life of a metallic member such as a bearing and worsening feeling of steering handle operation. <P>SOLUTION: A waterproof cap 33 is attached to a part of a steering shaft 26 protruding upward from an upper end of the steering column 27 to prevent rainwater from entering the inside of the steering column 27 through a clearance between the steering shaft 26 and a rubber bush 32. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a steering column in a wheel type steering device provided on a traveling vehicle such as a tractor. More specifically, the present invention relates to a structure for preventing water from entering the steering column of a tractor and a structure for preventing a steering operation feeling from changing over time.

[0002]

2. Description of the Related Art Conventionally, the steering wheel of a tractor has been rotated by turning a knuckle arm through an arm or a link to turn a steering wheel, or by transmitting it to a hydraulic control unit. According to the rotation of the handle, pressure oil is sent from the control unit to expand and contract the power steering cylinder, and the steering wheel is rotated left and right to perform steering. The upper part was supported by a rubber bush and the lower part was supported by a bearing between the steering column and the steering shaft, but there was a gap between the steering shaft and the rubber bush. There was no structure to drain the accumulated water.

[0003]

Therefore, in the structure of the conventional steering column, water such as rainwater may enter through the gap between the steering shaft and the rubber bush arranged above the steering shaft. There has been a problem that rust is generated in the bearings and other metal members that are fitted and fixed in the lower part of the column to shorten the life of the bearings and the like.

Further, since no water drain hole or the like for draining water in the steering column is provided, it is not possible to drain water due to dew condensation generated inside the steering column to the outside, and similarly, the bearing is rusted. Therefore, there is a fear that the operation feeling during steering operation may be deteriorated due to adverse effects such as occurrence of a steering wheel. Therefore, there has been a demand for means capable of preventing the operation feeling from changing over time.

The problem to be solved by the present invention is as described above, and the means for solving this problem will be described below.

That is, in claim 1, the steering shaft is supported in the pipe-shaped steering column,
In a structure in which a steering handle is fixed to the upper portion of the steering shaft, a waterproof cap that covers the upper portion of the steering column is attached to the outer periphery of a portion of the steering shaft that projects upward from the steering column.

According to a second aspect of the present invention, the steering shaft is supported in the pipe-shaped steering column, and the steering handle is fixed to the upper portion of the steering shaft. In the structure, a seal member is provided at a connecting portion between the steering shaft and the steering handle. It is arranged.

According to a third aspect of the present invention, the steering shaft is supported in the pipe-shaped steering column, and the steering handle is fixed to the upper portion of the steering shaft. The lower part of the rotating base of the steering handle is parallel to the steering shaft. The steering handle is configured so as to extend downward and the extension portion of the steering handle covers the upper outer periphery of the steering column.

According to a fourth aspect of the present invention, a steering shaft is supported in a pipe-shaped steering column, and a steering handle is fixed to an upper portion of the steering shaft. A bearing is provided between a lower portion of the steering column and a lower portion of the steering shaft. It is supported by being interposed, a rotor for drainage is attached to a steering shaft above the bearing, and a drain hole is opened in a steering column in which the rotor is located.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, embodiments of the present invention will be described. FIG. 1 is a side view showing an overall configuration of a tractor according to an embodiment of the present invention, and FIG. 2 is a side view essential sectional view of a steering column showing an embodiment with a waterproof cap attached. FIG. 3 is a cross-sectional view of a main part of a steering column showing an embodiment in which an O-ring is used for sealing and an embodiment in which a lower portion of a steering handle is extended. FIG. 4 is a cross-sectional view of a main part of a side view of a steering column showing another embodiment sealed by an O-ring. 5 is a side sectional view of a main part of a steering column showing an embodiment in which a water extrusion rotor is attached, FIG. 6 is a plan sectional view of a water extrusion rotor, and FIG. 7 is a side sectional view of a conventional steering column.

Referring to FIG. 1, the overall structure of the tractor 1 will be described. A front wheel 2 and a rear wheel 3 are supported at the front and rear of the machine, an engine 5 is arranged inside the front bonnet 4, and a steering handle 6 is provided at the rear of the bonnet 4 and at the rear of the steering handle 6. Seat seat 7
Are installed. Further, a main shift lever and the like are arranged on the side of the seat 7.

The engine 5 is anti-vibration-supported on the front frame 8, and a transmission case 11 is arranged in the rear portion of the engine 5 via a clutch housing to change the power from the engine 5 to change the rear wheels 3. It is possible to transmit the driving force to the front wheels 2 at the same time from the transmission case 11 via the transmission device.

Further, the driving force of the engine 5 is transmitted to the PTO shaft protruding from the rear end of the transmission case 11, and the PTO shaft is projected.
The work machine mounted from the TO shaft is driven via a work machine mounting device 13 arranged at the rear end of the machine body via a universal joint or the like. A hydraulic case 10 is placed on the upper part of the transmission case 11, and a cylinder is housed in the hydraulic case 10 to lift the lift arms 19.
And the work implement mounting device 13 is composed of a top link 20 and lower links 21 and 21, and the lift arms 19 are rotated by rotating the lower links 21 and 21 via a lift rod. The working machine mounting device 13 can be moved up and down.

A dashboard 23 is provided at the rear of the bonnet 4, and the dashboard 23 covers and covers a steering column 27, which will be described later. On the dashboard 23, an instrument panel, key switches, and a forward / reverse switching lever are provided. 22 and the like are arranged, and a floor cover 25 is provided at the lower part of the dashboard 23 as a step and is fixed to the machine body side such as a clutch housing and a transmission case.

The center of the steering handle 6 is shown in FIG.
The steering shaft 26 is fixed to the upper end of the steering shaft 26, and the lower end of the steering shaft 26 is connected to the input shaft of the hydraulic control unit (orbit roll) of the power steering device. However, the knuckle arm may be configured to rotate via a link or the like.

The steering shaft 26 is the bearing 2
It is supported by a steel pipe-shaped steering column 27 via 9 and the lower part of the steering column 27 is fixed to the control unit with bolts or the like via a mounting plate.

In the structure of the conventional steering column, as shown in FIG. 7, at the upper end of the steering shaft 26 protruding upward from the upper end of the steering column 27, there is a serration portion 31 for preventing relative rotation with the steering handle.
The steering handlebar 6 is fixedly mounted through the steering shaft 26, and the lower portion of the steering shaft 26 is supported by a bearing 29 that is internally fitted and fixed to the steering column 27.
The upper portion thereof is supported by the rubber bush 32. The rubber bush 32 is disposed between the upper portion of the steering column 27 and the outer periphery of the upper portion of the steering shaft 26 and is used as a vibration isolating member. However, rainwater or the like enters between the steering handle 6 and the steering column 27 to prevent the steering. Water was infiltrating between the shaft 26 and the rubber bush 32.

Next, a structure for preventing water from entering the steering column will be described with reference to FIGS. 2, 3 and 4. First, a first embodiment will be described with reference to FIG. The rotation support portion (base portion) of the steering handle 6 is a boss 39.
Is fitted and fixed to the serration portion 31 at the upper end of the steering shaft 26, and the upper end of the steering shaft 26 is fixed by tightening a nut 44. The nut 4
The upper part of 4 is covered with a wheel cap 14. A waterproof cap 33 is attached to the outer periphery of the lower portion of the boss 39 in the rotation support portion (base portion) of the steering handle 6 on a part of the steering shaft 26, and the waterproof cap 33 is attached.
Is mounted so as to rotate integrally with the steering shaft 26, thus ensuring a reliable seal between the two. The waterproof cap 33 is formed in a funnel shape so that the lower part has a large diameter, and the lower part of the waterproof cap 33 is disposed in close proximity so as to cover the outer periphery of the upper part of the steering column 27. Further, since there is a gap between the waterproof cap 33 and the steering column 27 and they are not in contact with each other, a waterproof structure that does not affect the operation feeling when the steering handle is rotated is provided. Will be done. The waterproof cap 33
An elastic member such as rubber or synthetic resin is used as the material of the.

Next, a second embodiment will be described with reference to FIG. In the mounting portion of the steering handle 6 base on the upper portion of the steering shaft 26, the steering shaft 2 in which the steering handle boss 39 is fitted
6. A ring-shaped groove is formed on the outer circumference of the steering wheel, and an O-ring 35 serving as a seal member is fitted into the groove to form a seal structure between the upper portion of the steering shaft 26 and the base of the steering handle 6. Wheel cap 14
Therefore, it is possible to prevent rainwater and the like from entering through the gap between the steering wheel 6 and the steering wheel 6.

The portion of the base of the steering handle 6 that covers the outside of the boss 39 extends downwardly in parallel with the steering shaft 26 to extend the steering column 2.
7 is configured to cover the upper part. That is, the cylindrical extending portion 6a is formed below the lower end of the steering handle 6 base.
And the extension 6a is formed on the steering column 27.
Are arranged close to each other so as to cover the upper outer periphery of As a result, the gap between the base of the steering handle 6 and the upper portion of the steering column 27 is eliminated as much as possible to provide a waterproof structure without adding other parts.

Next, a third embodiment will be described with reference to FIG. A ring-shaped groove 36 is provided on the inner surface side of the boss 39 at the upper portion of the serration portion 31 that connects the steering shaft 26 and the boss 39 of the steering handle 6.
An O-ring 37 serving as a seal member is fitted into the groove 36 to form a shaft seal structure. Thus, the steering shaft 26 and the boss 39 of the steering handle 6
This prevents rainwater and the like from invading the connection portion with the steering column 27 and prevents water from further intruding into the steering column 27 below, thereby preventing the steering shaft 26 and the steering handle 6 from sticking to each other due to rusting. An extension 6a is provided at the lower end of the base of the steering handle 6 as described above to prevent rainwater from entering between the boss 39 and the steering column 27.

Next, the structure of the lower portion of the steering column will be described with reference to FIGS. A bearing 29 with a seal is arranged between the lower portion of the steering shaft 26 and the lower portion of the steering column 27.
The grease that lubricates 9 is prevented from flowing out, and rainwater or the like that has entered from above does not enter the hydraulic control unit. Then, on the outer periphery of the upper portion of the bearing 29 arranged at the lower portion of the steering shaft 26,
A water extrusion rotor 41 for drainage is attached. The water extrusion rotor 41 is formed in a tubular shape, and as shown in FIG.
1a and 41b are provided and are attached to the outer circumference of the steering shaft so that the direction of the arrow X faces the front of the tractor, and rotate integrally with the steering shaft 26. Further, a water drain hole 42 is opened on the back surface (rear portion) of the steering column 27 at a position near the water pushing rotor 41 above the bearing 29. At this position, since the upper part of the steering column 27 is inclined rearward, the bearing 2
It is located at the bottom of the upper surface of the 9.

In such a structure, when rainwater infiltrates into the steering column 27 or condensed water collects in the lower part of the steering column 27, the water pushing rotor 41 is simultaneously operated by the steering wheel 6 when the steering handle 6 is rotated. As the shaft 26 rotates together with the shaft 26, the water accumulated in the notches 41a and 42b is pushed out from the drain hole 42 to the outside of the steering column. As a result, water due to dew condensation or the like generated inside the steering column is effectively discharged to the outside of the steering column. Further, since the bearing 29 has the seal structure, the rotation of the bearing 29 is prevented from being deteriorated due to the influence of moisture, and the influence such as the generation of rust due to the intrusion of water to the lower side is minimized. . The water extrusion rotor 4
As the material for No. 1, rubber, synthetic resin, or the like is used, and the drainage hole 42 is provided only at one location in the embodiment shown in FIG. 5, but is not limited to one location.

[0023]

Since the present invention is constructed as described above,
The following effects are achieved. That is, in a structure in which a steering shaft is supported in a pipe-shaped steering column and a steering handle is fixed to the upper portion of the steering shaft, the outer periphery of a part of the steering shaft protruding upward from the steering column as described in claim 1. Since a waterproof cap that covers the upper part of the steering column is attached to the steering column, it is possible to prevent water from entering the inside of the steering column through the gap between the steering shaft and the steering column, simply by providing an inexpensive cap. As a result, it is possible to prevent deterioration due to rusting of the bearing inside the steering column and generation of rust on other metal members. Especially, a tractor without a cabin is effective because it can prevent rainwater from entering.
In addition, the steering operation feeling during steering operation is not affected. Further, since the waterproof cap is attached to the steering shaft, the waterproof cap rotates integrally with the steering shaft, and the seal between the steering shaft and the waterproof cap can be reliably performed.

According to a second aspect of the present invention, the steering shaft is supported in the pipe-shaped steering column, and the steering handle is fixed to the upper portion of the steering shaft. In the structure, a seal member is provided at a connecting portion between the steering shaft and the steering handle. Since it has been arranged, it is possible to reliably block the water that enters from the part where the steering wheel is attached to the steering shaft by the seal member, prevent the intrusion of water into the steering column, and suppress the occurrence of rust on the metal member. .

According to a third aspect of the present invention, the steering shaft is supported in the pipe-shaped steering column, and the steering handle is fixed to the upper portion of the steering shaft. The lower part of the rotating base of the steering handle is the steering shaft. Since it extends downward in parallel, and the extending portion of the steering handle covers the outer periphery of the upper portion of the steering column, it is possible to block rainwater directly falling on the steering shaft and the upper portion of the steering column, and It is possible to prevent the infiltration of water, and to suppress the generation of rust on the metal member. Further, since the waterproof effect is exhibited without adding other parts, cost reduction can be achieved.

According to a fourth aspect of the present invention, the steering shaft is supported in the pipe-shaped steering column, and the steering handle is fixed to the upper portion of the steering shaft. The bearing is provided between the lower portion of the steering column and the lower portion of the steering shaft. The rotor for drainage is attached to the steering shaft above the bearing, and the drainage hole is opened in the steering column where the rotor is located. Through the vent hole, moisture accumulated inside the steering column such as dew condensation can be efficiently discharged, and the inside of the steering column can be prevented from being exposed to moisture. Then, it is possible to suppress deterioration of the steering operation feeling due to deterioration due to rusting of the bearing, and to maintain the operation feeling favorably for a longer period than in the past.

[Brief description of drawings]

FIG. 1 is a side view showing an overall configuration of a tractor according to an embodiment of the present invention.

FIG. 2 is a side view of a steering column showing an embodiment with a waterproof cap attached, which is a cross-sectional view of relevant parts.

FIG. 3 is a side view of the steering column, showing an embodiment in which an O-ring is used for sealing and an embodiment in which the lower portion of the steering handle is extended.

FIG. 4 is a cross-sectional view of a main part of a side view of a steering column showing another embodiment sealed by an O-ring.

FIG. 5 is a cross-sectional view of a main part of a side view of a steering column showing an embodiment in which a water extrusion rotor is attached.

FIG. 6 is a plan sectional view of a water extrusion rotor.

FIG. 7 is a side sectional view of a conventional steering column.

[Explanation of symbols]

6 steering wheel 6a Steering handle extension 26 Steering shaft 27 Steering column 29 bearings 33 waterproof cap 35, 37 O-ring 41 Water extrusion rotor 42 Drain hole

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Keiichi Hayashi             1-32 Yanma, Chayamachi, Kita-ku, Osaka-shi, Osaka             -Agricultural machinery Co., Ltd. F term (reference) 3D030 DC03 DC32

Claims (4)

[Claims] 1. In a structure in which a steering shaft is supported in a pipe-shaped steering column, and a steering handle is fixed to an upper portion of the steering shaft, a steering column upper portion is provided on an outer periphery of a part of the steering shaft protruding upward from the steering column. A steering device having a waterproof cap attached to cover the steering device. 2. In a structure in which a steering shaft is supported in a pipe-shaped steering column and a steering handle is fixed to an upper portion of the steering shaft, a seal member is arranged at a connecting portion between the steering shaft and the steering handle. Characteristic steering device. 3. A structure in which a steering shaft is supported in a pipe-shaped steering column, and a steering handle is fixed to an upper portion of the steering shaft, wherein a lower portion of a turning base of the steering handle extends downward in parallel with the steering shaft. The steering device is characterized in that the extending portion of the steering handle covers the outer periphery of the upper portion of the steering column. 4. A structure in which a steering shaft is supported in a pipe-shaped steering column, and a steering handle is fixed to an upper portion of the steering shaft, wherein a bearing is interposed between a lower portion of the steering column and a lower portion of the steering shaft. A steering apparatus comprising: a steering shaft above the bearing, a rotor for drainage being attached to the steering shaft, and a drainage hole being opened in a steering column in which the rotor is located.