JPS62177311A - Ball stud for ball joint - Google Patents

Abstract

PURPOSE:To reduce the relative movement in a loaded state and to enhance the safety of the captioned and at the time of abnormal abrasion, by providing a one-body shell of an almost hollow-and-spherical shape, which surrounds to a precompressed state, an elastic body surrounding the head part and harden ing the shank-side curved part of the shell by quenching. CONSTITUTION:After machining, the heat treatment is applied to the main body part, in which a head part 12 and a shank part 11 are formed into one body. The outer peripheral surface E of a curved part 15 of a shell 14 is har dened by quenching. Next, the shell 14 and the head part 12 are placed in a metallic mold, and rubber 13 is poured into the void space before the baking by vulcanization. Thus, a pre-compressive load is given to the rubber 13. If, in this state, a large load, which acts in the direction of extracting the head part 12, acts on the shank part 11, the large expanding force acts on an opening 17. However, since the expanding stress of the shank side curved part 15 has already been heightened and moreover since the stud is reinforced by the tip side curved part 14, which is not hardened yet and is tough, the opening 17 shows high resistance to the expansion and cracking, thereby preventing both shank part 11 and shell 14 from coming out of a housing 2.

Description

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

BACKGROUND ART In a ball joint that has a sliding structure between a ball stud ball head and a bearing that supports the outer periphery of the ball head, the head at one end of the ball stud handle and a shell forming the outer periphery of the ball head There is a ball stud with an elastic body interposed between them called JP-A-57-29soc+g, and a ball stud with pre-compression applied to the intervening elastic body is JP-A-57-1.
There is No. 815.

Problems to be Solved by the Invention In this type of ball stud, the handle part is made of an elastic material so that it does not come into contact with the shell or housing, and the ball joint maintains low operating torque characteristics while improving the vibration-proofing and shock-absorbing characteristics of the ball joint. It serves its original purpose.

However, as the thickness of the elastic body increases, it becomes difficult to remove the handle from the shell, resulting in a problem that the applications are extremely limited.

That is, when an impact load is applied in the direction of pulling the handle out of the shell, there is a risk that the handle will pull out from the shell above the designed level even if the opening on the handle side of the shell expands slightly.

In addition, this type of ball stud has one part of the handle against the shell.
Since the relative movement is large, it is necessary to apply a large precompression to the intervening elastic body, and if the bearing causes abnormal wear due to the intrusion of dust, etc., the housing and shell will directly rub against each other, and the There was a risk that the shell would wear out and the stud would come off from the housing, which would lead to the worst case scenario, and it was desired that this problem be resolved.

Means for solving the problem: A handle having a head at one end, an elastic body such as rubber surrounding the head, and a substantially hollow spherical integral shell surrounding the elastic body in a pre-compressed state. , and the curved portion of the shell on the handle side is hardened by quenching.

The deformation resistance of the curved part on the handle side of the shell is high, especially the expansion stress of the opening on the handle side is high, and the tip side of the opposite side, which is unhardened, is curved into a hemispherical shape to improve elasticity. Can apply pre-compression to the body.

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

FIG. 1 shows a ball stud 10 for a ball joint, and FIG. 3 shows a ball joint 1 to which the ball stud 10 is attached.

This ball joint 1 includes, in addition to a ball stud 10, a synthetic resin bearing 5 that supports the spherical head of the ball stud, a urethane rubber bearing 6, and a housing that houses these spherical heads and bearings 5, 6. 2 and a closing plate 4 for closing the opening at one end of the housing.

Ball stud 10Fi includes a handle 11, a spherical head 12 at one end of the handle, an elastic body 18 such as rubber surrounding the head 12, and a substantially hollow spherical shape surrounding the elastic body 13 in a pre-compressed state. It is equipped with a steel integral shell 14.

This shell 14 has a substantially uniform wall thickness, and a curved portion 15 on the handle side of the shell is hardened by quenching.

The ball stud 10 also has a shell 14 that slides on the bearings 5, 6, causing the handle 11 projecting from the housing opening 3 to swing and rotate.

Next, a method of manufacturing the ball stud 10 will be explained.

The body portion in which the bulging head 12 and the handle 11 are integrally formed is formed in advance by cold plastic working, and if necessary, heat treatment such as carburizing and quenching is applied to increase the fatigue strength of the handle.

As shown in FIG. 2, the shell 14 is prepared in advance by having a predetermined hemispherical curved portion 15 on one end side, and by subjecting the outer surface range E of the curved portion 15 to hardening treatment such as induction hardening. be done.

The curved portion 15 of the shell 14 can be formed by squeezing a round cylindrical material from the axial direction with a cup die 20.

Next, the shell 14 and head 12 are placed in a mold (not shown), and rubber 13 is injected into the opposing space between the two as shown in FIG. The tip end side of the shell 14 is also formed into a hemispherical curved portion 16 using a cup die 20, 21 as shown by the two-dot chain line in FIG.

As the shell 14 is formed into a spherical shape in this manner, a precompression load is applied to the rubber 13, and the rubber 13 is placed between the shell 14 and the head 12 in a precompressed state.

The shape of the bulging head 12 of the ball stud 10 is not limited to a spherical shape, but may be an abacus bead shape as shown in FIG. 4.

Next, the function of the ball stud 10 will be explained in a state where it is assembled to the ball joint 1 as shown in FIG. 3.

Assuming that a load is applied to the handle 11 in the direction of pulling out the head 12 from the housing opening 3, if the load is relatively small, the rubber 13, which is an elastic body, may be pre-compressed, and the design value The handle portion 11 moves relative to the housing 2 within the housing.

Furthermore, if the pull-out load is large and impactful, a considerable expansion force acts on the handle-side opening 17 of the shell 14, but the expansion stress of the handle-side curved part 15 is increased and the unhardened and strong Since the distal end side curved portion 14 is reinforced, it exhibits high resistance to expansion and cracking, and prevents the handle portion 11 and the shell 14 from coming off from the housing 2.

Furthermore, even when the bearings 5 and 6 that support the shell 14 are abnormally worn due to the intrusion of dust or the like, the quench-hardened handle-side curved portion 15 and the same surroundings of the housing opening 3 rub against each other. will not wear out in a short period of time.

Effects As described above, according to the present invention, the deformation resistance of the curved part on the handle side of the shell is large, the expansion stress in the opening on the handle side is particularly high, and the tip side of the opposite side, which is unhardened, is shaped like a hemisphere. By curving it into a shape, a pre-compression load can be applied to the elastic body, so
It is possible to prevent the stud from coming out of the housing even when a shocking and large pullout load that exceeds conventional design standards is applied, and at the same time achieve safety measures in the event of abnormal wear. Relative movement can be reduced.

[Brief explanation of drawings]

FIG. 1 is a sectional plan view of a ball stud for a rubber ball joint according to an embodiment of the present invention. 21st. 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 ball joint according to an embodiment of the present invention. (Explanation of symbols) 1...Rubber ball joint. 10...
...Ball stud. 11...Handle. 12...
...Head. 13...Elastic body. 14...
...shell. 15... Curved part on the handle side. 16...
Opening side curved part.

Claims (1)

[Claims] A ball stud 10 for a ball joint structured to slide between a ball head and a bearing supporting the ball head includes a handle 11 having a head 12 at one end, and a handle 11 surrounding the head 12. an elastic body 13 such as rubber, and a substantially hollow spherical integral shell 14 that surrounds the elastic body 13 in a pre-compressed state, and a curved portion 15 on the handle side of the shell 14 is hardened by quenching. A ball stud for ball joints featuring: