JPS6224021A - Ball stud for rubber ball joint - Google Patents

Abstract

PURPOSE:To reduce the amount of movement in the axial direction of a ball stud when an axial load is added, by making greater the precompression load of rubber at the end side parts of rubber in the axial direction of a ball stud and making smaller at the intermediate part in between. CONSTITUTION:A ball stud 2 has a global bulged part 4 at one end of a shaft part 3, a compressed rubber 6 which almost surrounds the bulged part 4 and an almost global shell 5 which almost surrounds the rubber 6. And it is so made that, at the end side parts 8, 9 of the rubber 6 in the axial direction of the ball stud, the precompression load of rubber 6 is larger and further, at the intermediate part 7 in between, the precompression load of rubber 6 is smaller.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a ball stud for a rubber ball joint that has improved vibration and shock absorption performance and is used in automobile suspensions, steering linkages, and the like.

2. Description of the Related Art Conventional technology relating to a ball joint in which an elastic body such as rubber is arranged on the spherical head itself or its outer circumference to improve vibration and shock absorption performance includes, for example, US Patent No. 3. 4.95.858 etc.

Problems to be Solved by the Invention This type of rubber pole joint, as shown in FIG. Quantity I
(1, I(2 is too large.

That is, in this type of rubber ball joint IC, since the ball stud head 4C is supported in a floating manner by the rubber 60, the elastic body deforms excessively under a large load.
There is a problem that the amount of relative movement is too large.

Another means of solving the problem is to increase the precompression load of the rubber at the end portions of the rubber in the axial direction of the ball stud and to reduce it at the intermediate portion therebetween.

Operation When an axial load is applied to the ball stud shaft in the temporarily fixed state, there is little deformation of the rubber end portion in the ball stud axial direction.

Embodiment The structure of an embodiment of the present invention will be explained below based on the drawings.

FIG. 1 shows a ball stud 2 for a rubber pole joint, and FIG. 3 shows a rubber pole joint 1 to which the ball stud 2 is attached.

This rubber ball joint includes a ball stud 2, a socket 11, and an upper bearing 14 made of synthetic resin.
, a lower bearing 15 made of urethane rubber, a spherical shell 5 made of steel, rubber 6 filling the inside of the shell 5, and a closing plate 13.

The socket 11 has a substantially cylindrical shape and has openings at both ends, one of which is closed by a closing plate 13, and the other opening 12 allows the shaft 3 of the ball stud 2 to protrude swingably.

The ball stud 2 has a spherical bulge 4 at one end of a shaft 3, a compressed rubber 6 that substantially surrounds the bulge 4, and a substantially spherical shell 5 that substantially surrounds the rubber 6.

Next, a method of manufacturing the ball stud 2 will be explained.

The main body portion of the ball stud 2 having the shaft portion 3 and the bulging head portion 4 is formed in advance by cold plastic working, and is subjected to heat treatment such as carburizing and quenching if necessary.

The spherical shell 5 is prepared as a cylindrical shell 5 pre-formed to a predetermined size as shown in FIG.

First, the bulging head 4 is placed at a predetermined position on the inner circumference of this cylindrical shell 5 in a mold (not shown), and a rubber 6 is placed in the space facing each other.
is injected and subjected to vulcanization and baking treatment, and then the shell 5a is formed into a spherical shape using a cup die or the like as shown by the two-dot chain line in FIG.

As the shell 5 is formed into a spherical shape, the rubber 6
The rubber 6 is attached to the end portions 8 and 9 of the ball stud in the axial direction.
The precompression load of the rubber 6 is large, and the precompression load of the rubber 6 is small in the intermediate portion 7 between them.

In order to obtain a similar precompression load, the shape of the bulging head 4 of the ball stud 2 is not limited to a spherical shape. For example, as shown in FIG. It may be ball-shaped. Also, this spherical shell 50
When forming from a cylindrical shell, the forming load may be applied from a direction perpendicular to the stud axis, such as by rolling, and if necessary, the diameter of the cylindrical shell may be reduced so that the diameter of the spherical shell is smaller. It's okay to be depressed.

Next, the function of the ball stud described above will be explained with the ball stud 2 configured as a rubber ball joint 1 shown in FIG. 3.

When using this rubber pole joint, the ball stud 2
When a load is applied in the axial direction of the stud, the bulging head 4
compresses and deforms the rubber 6 to move relative to the socket 11, but the stud axial end portions 8, 9 of the rubber 6
Since a large precompression load is applied in advance to the area, the amount of compressive deformation at that part is small. Therefore, the amount of relative movement is much smaller than that of a conventional rubber ball joint in which the head of a ball stud is supported in a floating manner by rubber.

Note that this ball stud 2 does not increase the overall hardness of the rubber in order to reduce the amount of relative movement, so the precompression load on the end portions 8 and 9 is increased, and the precompression load on the intermediate portion 7 between them is increased. Based on the basic condition of making the pole joint as small as possible, it is possible to give the desired vibration and shock absorption characteristics by changing the shape of the bulging head, the shape of the rubber injection, and the amount of constriction of the shell according to the location where the pole joint is used. can.

Effects As described above, according to the present invention, when an axial load is applied to the ball stud shaft in a temporarily fixed state, there is little deformation of the end portion of the rubber ball stud in the axial direction, so that the bulging head is formed within the spherical shell. The amount of movement in the axial direction of the ball stud can be greatly reduced while the part is floatingly supported by rubber.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional plan view of a ball stud for a rubber pole joint according to an embodiment of the present invention. FIG. 2 is a cross-sectional plan view of the ball stud shown in FIG. 1, which is in the process of being manufactured. FIG. 3 is a cross-sectional plan view of a rubber ball joint in which the stud of FIG. 1 is incorporated. FIG. 4 is a cross-sectional plan view of a ball stud for a rubber pole joint according to another embodiment of the present invention. Fifth
The figure is an explanatory cross-sectional view of a conventional rubber pole joint. (Explanation of symbols) ■・・・Rubber ball joint. 2...
・Ball stud. 3...Shaft part. 4...Bulging head. 5... Shell. 6...
... Lava-. 7...Middle part of the rubber. 8,9...
・Rubber end part.

Claims (1)

[Claims] a head 4 formed in a bulge on the shaft portion 3 of the ball stud 2;
A compressed rubber 6 that substantially surrounds the bulging head 4 and a substantially spherical shell 5 that substantially surrounds the rubber 6 are provided,
A ball stud for a rubber ball joint, characterized in that the precompression load of the rubber 6 is large at end portions 8 and 9 of the rubber 6 in the ball stud axial direction, and small at an intermediate portion 7 therebetween.