JPH0318740Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a ball joint in which a stable operating torque of a ball stud can be obtained despite variations in dimensional accuracy during assembly by incorporating a highly elastic member such as rubber as a bearing member.

2. Description of the Related Art Conventionally, there is a ball joint used in steering linkages, suspensions, etc. of automobiles, as shown in FIG. 3, for example.

1 is a ball joint socket, which has a screw hole 1a at the lower end for connecting with a link member, and inside the ball joint socket 1, a ball stud is inserted through a bearing 2 made of a highly wear-resistant plastic material. 3 is slidably attached to the ball joint socket 1. To assemble the ball stud 3 to the ball joint socket 1, the plate 5 is fitted following the bearing 2, and the opening edge 6 of the ball joint socket 1 is caulked, and this caulking load is applied. A specified operating torque is obtained by the sliding resistance between the bearing 2 and the ball stud spherical portion 4, which is determined by the following. However, in conventional ball joints, the bearing 2 is made of a highly wear-resistant plastic material, and since it is a low elasticity member, the elastic force changes greatly due to variations in the dimensional accuracy of the component parts, and the ball stud There has been a problem in that the actuation resistance is either too high or too low, making it difficult to obtain an appropriate actuation resistance.

The present invention was developed in view of these conventional problems, and uses a bearing structure that combines a high elasticity member and a low elasticity member to provide an appropriate operating resistance of the ball stud even if there are variations in dimensional accuracy when press-fitting the bearing. The purpose is to make it possible to

FIG. 1 shows an embodiment of the present invention, in which reference numeral 10 denotes a ball joint socket, which consists of a bearing body 14 made of a high elasticity material and an inclusion 18 made of a low elasticity material integrally combined with the bearing body 14. Fit the spherical part of the lower end of the ball stud 13 into the bearing, press fit the bearing into the upper opening of the socket 10, place the plate 11 on the upper surface of the bearing, and swage the edge of the upper opening of the socket 10 to assemble. It is attached and fixed. 12 indicates a caulking portion.

The structure of the above-mentioned bearing includes a bearing body 1 made of a highly elastic material such as urethane or rubber material.
4, a plurality of thin walled portions 15 are formed at predetermined intervals on the circumferential side portion from near the middle portion in the vertical direction to the upper end portion, so that a plurality of radial portions 16 extend inward between the thin walled portions. The lower part of the bearing body 14 from the vicinity of the middle part is a thick wall part 17, and the bearing body 14 has a thin wall part 15.
An inclusion 18 made of a low-elasticity material such as plastic is integrally filled into the space created by the radial part 16, and the middle part in the vertical direction of the spherical part at the lower end of the ball stud 13 is connected to the inner end surface of the radial part 16 and the inside of the inclusion 18. The structure is such that the inner surface of the thick portion 17 is pressed against the lower portion of the spherical portion.

FIG. 2 shows another embodiment of the present invention. In the embodiment shown in FIG. The top of 10 is 10a
The bearing is pressed and fixed by squeezing the bearing inward as shown in FIG. The space between the thin wall portion 15 and the inner circumferential surface of the socket 10 is filled with an inclusion 18 made of a low elastic material such as plastic, and the lower spherical portion of the ball stud is inserted into the inner circumferential surface of the bearing body 14 made of a high elastic material. It has a structure that allows it to be held under pressure.

The bearing molding method uses, for example, polyamide resin, polyacetal resin, reinforced plastic, etc. as a low elasticity member with high wear resistance, and uses a high elasticity member such as urethane or rubber material that has large elastic deformation under caulking or drawing load. However, by composite molding, the high and low elastic members are made as an integral part of the bearing.

In the configuration of the present invention, a highly elastic material such as rubber is used as the bearing body, and an inclusion made of a highly elastic material is partially integrally filled on the inner peripheral surface or outer peripheral surface from near the middle in the vertical direction to the upper end. Because of this structure, the change in the operating torque of the ball stud (see Figure 4) due to the bearing press-fit allowance due to caulking or narrowing of the upper opening of the socket mainly depends on the elastic force of the highly elastic member. Even if there is variation in the dimensional accuracy of the press-fit allowance, the change in operating torque due to this variation can be significantly reduced compared to conventional ball joints, and the dimensional accuracy of the bearing and press-fit parts can be improved even after assembly. Appropriate operating torque can be obtained, and the quality of the ball joint can be greatly improved.

In Fig. 4, the horizontal axis shows the bearing press-fitting allowance, and the vertical axis shows the operating torque, A shows the conventional example, and B shows the example according to the present invention. It can be seen that there is a large difference in the width of the operating torque change in case b1−b2.

In addition, by partially interposing an inclusion made of a low elastic material only in the bearing portion that holds the vertically intermediate portion of the lower end spherical portion of the ball stud,
The rigidity of the bearing part is increased, the operating torque is stabilized, and the holding strength against the pull-out load acting on the ball stud can be ensured, which can bring about great practical effects.

[Brief explanation of the drawing]

FIGS. 1 and 2 each show an embodiment of the present invention, and in each figure, A is a longitudinal cross-sectional view, and B is a cross-sectional view. FIG. 3 is a longitudinal sectional view of a conventional example for comparison. FIG. 4 is a diagram illustrating the effect of the present invention in comparison with a conventional example. 10... Ball joint socket, 11...
Plate, 12... Caulked portion, 13... Ball stud, 14... Bearing body, 15... Thin wall portion, 16... Radial portion, 17... Thick wall portion, 18...
...Inclusions.

Claims (1)

[Scope of utility model registration request] An automobile comprising a ball stud, a bearing that fits and holds a spherical part at the lower end of the ball stud, and a socket into which the bearing is press-fitted from an opening at the upper end and the bearing is press-fixed by caulking or squeezing the periphery of the upper opening. In such a ball joint, the bearing is formed with a plurality of thin-walled portions at predetermined intervals in the circumferential direction on the inner or outer periphery from near the middle portion in the vertical direction to the upper end, and a plurality of thin-walled portions are formed between the thin-walled portions. The bearing body is made of a high-elasticity material with extended radial parts and a thicker part from near the middle part in the vertical direction to the lower end, and a low-elasticity material filled in the space formed by the thin-walled part of the bearing body. The ball stud is integrally constructed with an inclusion made of a member, and the vertically intermediate portion of the lower end spherical portion of the ball stud is pressed and held by the portion filled with the inclusion, and the lower portion of the spherical portion is pressed and held by the thick portion. A ball joint characterized by being held in place.