JPS6127330Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a center arm support device for a steering linkage.

In the steering link mechanism of a cab-over vehicle in which the front wheels are independently suspended, a center arm and a drag link are provided between the relay rod and the pitman arm of the steering gear. That is, in FIGS. 1 and 2, the nut arms 2, 2' of the front wheels 1, 1' on both sides of the vehicle are connected to the vicinity of the end of a relay rod 4 via tie rods 3, 3', respectively. One end of the relay rod 4 is connected to a pitman arm 8 of a steering gear 7 via a rectangular center arm 5 and a drag link 6, and the other end of the relay rod 4 is connected to an underarm arm 9.
is connected to.

The center arm is supported by the vehicle body, for example, by an arm support device 10 shown in FIG. In other words, the arm shaft 1 is attached to the lower end of the square center arm 5 at a corner thereof at right angles to the plane formed by both arms of the arm.
1 is two synthetic resin bushings, lower and upper.
The housing 14 is rotatably supported by a housing 14 via 2 and 13, and the housing 14 is fixed to the vehicle body by screws passed through four holes 16 in a flange 15 of the housing 14. In order to apply a downward axial preload to the arm shaft 11, the arm shaft 11
A coil spring 19 was provided between a flange 17 at the upper end and a lid 18 covering the top of the housing 14. However, if used for a long period of time, wear of the bushes 12 and 13 will cause backlash in the direction perpendicular to the arm shaft 11, reducing the rigidity of the link mechanism and adversely affecting the feeling of steering. The disadvantage was that it was not possible to adjust the preload.

The present invention eliminates the above-mentioned drawbacks by supporting the arm shaft of the center arm by a needle bearing and a tapered roller bearing, and by using a spring to press the arm shaft in the tapered direction of the taper.

An embodiment of the invention is shown in FIG. Here, parts corresponding to those in FIG. 3 are given the same reference numerals. According to the present invention, the lower part of the arm shaft 11 is supported by the housing 14 via the needle roller bearing 21, and the upper part is supported by the housing 14 via the tapered roller bearing 22. Arm axis 11
Coil spring 1 providing a downward axial preload of
9 is made up of a thrust washer 25 that rests with small friction on a washer 24 that pushes the bearing inner ring 22a downward by a nut 23 screwed into a bolt portion at the upper end of the arm shaft in order to fix the tapered roller bearing 22 to the arm shaft 11, and the housing lid 18. is provided in between. This spring 19 allows the tapered roller bearing 22
is given radial and axial preload, and the play is zero. Therefore, it is only necessary to use a needle roller bearing 21 with a small play.

The fifth embodiment is one in which the preload of the spring 19 is adjustable.
As shown in the figure. Here, a washer 26 with low friction against the flange 17 is placed on the flange 17 at the upper end of the arm shaft 11, and between this washer 26 and a male screw cap 27 that is screwed into the female thread cut into the upper inner wall of the housing 14. A spring 19 is provided. Hole 2 in the male screw cap 27
By inserting a suitable tool into the spring 19 and turning the externally threaded cap 27, the preload of the spring 19 can be adjusted in accordance with its axial dimension.

In this way, according to the present invention, roller bearings 21 and 22 are used instead of conventional bushings to support the arm shaft 11 of the center arm to the housing 14, so there is almost no wear and it lasts for a long time. Can withstand use. Moreover, since the tapered roller bearing 22 is preloaded in the tapered direction by the spring 19 and the play is always zero, it is only necessary to select a needle roller bearing 21 with a small play. In addition, if the axial load can be adjusted according to the wear of the bearing 22, even if wear occurs due to long-term use, the axial preload can be changed according to this wear, so that the steering feel is always maintained. Well kept.

Although the preferred configuration for assembly and adjustment is shown in the embodiment, within the scope of the technical idea of the present invention, the relative axial position of the double roller bearing, the position of the spring,
It is possible to arbitrarily select the spring preload adjustment mechanism according to the respective conditions.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of the steering link mechanism, Figure 2 is a perspective view of its important parts, Figure 3 is a partially cutaway front view of a conventional center arm support device, and Figures 4 and 5 are FIG. 2 is a partially cutaway front view of the center arm support device according to the present invention. 5... Center arm, 10... Arm support device, 1
1...Arm shaft, 14...Housing, 18, 27...
Lid, 19... Spring, 21... Needle roller bearing, 22
...Tapered roller bearing.

Claims (1)

[Scope of utility model registration request] An arm shaft fixed perpendicularly to the center arm of the steering link mechanism is supported on the vehicle body fixing member by needle roller bearings and tapered roller bearings arranged along this arm shaft, and an axial force directed in the tapering direction of the taper is generated. A center arm support device for a steering link mechanism, characterized by being provided with a spring that applies force to the center arm shaft.