JPS6027089Y2 - Steering mechanism in agricultural tractors - Google Patents

Description

[Detailed description of the invention] The invention is a steering mechanism for an offset type agricultural tractor. Specifically, the invention is a steering mechanism for an offset type agricultural tractor. Specifically, the invention is a steering mechanism in which a fixed support shaft has a rocking mechanism for relaying the operating force of the steering wheel to a pair of left and right steering knuckles. This invention relates to a steering mechanism in which an arm is fitted onto the outside so that it can only rotate freely.

Generally, this type of steering mechanism is installed at a low location relative to the ground, so muddy water and dust can easily enter between the outer circumferential surface of the fixed support shaft and the inner circumferential surface of the pivot boss of the swing arm. This acts as rotational resistance for the movable arm, making it difficult to rotate the steering wheel.

Conventionally, a collar was interposed between the pivot boss of the swing arm and a retaining pin inserted through the tip of the fixed support shaft. Since the fixed support shaft frequently moves in the axial direction due to vibrations of the aircraft, it is inevitable that muddy water and dust will enter through the gap created between this collar and the pivot boss, causing the above-mentioned problems. It was easy.

In view of the above-mentioned circumstances, the present invention is a simple structural improvement of the pivot part of the swing arm, and its purpose is to completely prevent the intrusion of muddy water and dust. .

The features of the present invention to achieve the above objectives are as follows:
A pivot boss portion of a swinging arm for relaying and transmitting the operating force of the steering handle to a pair of left and right steering knuckles is externally fitted onto the fixed support shaft so that only the swinging arm can rotate freely, and the swinging arm is fixedly supported. a contact portion that is pivotably supported on the shaft and that contacts the upper end of the pivot boss portion of the swing arm to prevent the swing arm from being pulled out from the fixed support shaft; A cap, which is formed as a pair of a pivot boss portion and a part of a cover for covering the upper part of the fitting sliding surface of the fixed supporting shaft and protecting the fitting sliding surface from dust, is attached to the fixed supporting shaft. It is fixed at the upper end, and this configuration provides the following effects.

In other words, by attaching the cap to the pivot host portion of the swing arm, there is no gap caused by vibrations of the machine as mentioned above, and the outer circumferential surface of the fixed support shaft and the swing arm are securely connected. The rotational operation of the steering bundle can be maintained smoothly at all times by reliably preventing muddy water and dust from entering between the inner circumferential surface of the pivot host part and the inner circumferential surface of the pivot host part.

Moreover, since the cap also serves to prevent the pivot boss from coming off, the structure for preventing the pivot boss from coming off can be easily constructed by effectively utilizing such a dustproof structure.

Therefore, by simply attaching the cap to the pivot boss portion of the swing arm, it has become possible to improve the dust-proofing effect and simplify the slip-out prevention structure.

Embodiments of the present invention will be described below based on the drawings.

Figure 1 shows the engine, the transmission mechanism for the pair of left and right rear wheels 1, 1, and the transmission mechanism for the work system internally housed in the transmission case 2, etc., with the drive system being moved to one side with respect to the center of the aircraft's width. A pair of left and right front wheels 1, 1
The steering mechanism 4 is designed to operate an offset type agricultural tractor in which a steering bundle 5 and a driver's seat 6, which are operated via the steering mechanism 4, are arranged in the center of the body width. As shown in the figure, it is structured as follows.

That is, the operating force of the steering bundle 5 received via the pitman arm 9 and the drag ring 10 of the steering gear case 8 is transferred to the fixed support shaft 7 provided in the machine frame in the vertical direction by the pair of left and right steering knuckles 11.11. Swinging arm 1 for relay transmission via tie rod 12.12 to
The upper end of the pivot boss 13A of the swing arm 13 is fitted onto the threaded portion 7a formed at the upper end of the fixed support shaft 7. A cap 14 having a space 14A that can be fitted therein is screwed together to prevent dust and prevent the pivot boss portion 13A from being removed.

Further, the lock bolt 16 is screwed onto the fixed support shaft 7 through the through hole 15 formed in the upper surface portion 14a of the cap 14a, and the bent tongue piece 17a of the washer 17 fitted onto the lock bolt 16 is inserted into the cap. 14 is engaged with a tool insertion step 18 formed on the upper surface portion 14a.

The upper surface portion 14a of the cap 14 constitutes a part of a cover that covers the upper part of the fitting sliding contact surface between the fixed support shaft 7 and the pivot boss portion 13A of the swing arm 13, and the cap 14 A contact portion 14b that contacts the upper end of the pivot boss portion 13A and prevents the pivot boss portion 13A from being pulled out is provided on the lower surface portion opposite to the upper end portion of the pivot boss portion 13A.
It is an integral form of formality.

[Brief explanation of the drawing]

The drawings show an embodiment of the steering mechanism for an agricultural tractor according to the present invention, in which Fig. 1 is an overall plan view of an offset type agricultural tractor, Fig. 2 is an enlarged partially cutaway view of the main parts, and Fig. 3
The figure is a perspective view of main parts. 5... Steering bundle, 7...
Fixed support shaft, 11...Steering knuckle, 13...
...Swinging arm, 13A...Pivot boss part,
14...Cap, 14a...Part of cover, 14b...Abutment part.

Claims (1)

[Scope of utility model registration request] The pivot boss portion 13A of the swing arm 13 for relaying the operating force of the steering handle 5 to the pair of left and right steering knuckles 11.11 is externally fitted onto the fixed support shaft 7 so as to freely rotate only. The swing arm 13 is swingably supported on the fixed support shaft 7, and the fixed support shaft 7 of the swing arm 13 is in contact with the upper end portion of the pivot boss portion 13A of the swing arm 13. a contact portion 14b that prevents the pivot boss portion 13A from being removed from the fixed support shaft 7; and a cover that covers the upper portion of the fitting sliding surface between the pivot boss portion 13A and the fixed support shaft 7 to protect the fitting sliding surface from dust. A steering mechanism for an agricultural tractor, in which a cap 14 integrally formed with a portion 14a is fixed to an upper end portion of the fixed support shaft 7.