JPH0730779B2 - Dust cover seal structure for ball joints - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure for a ball joint dust cover used in, for example, an automobile suspension system and a steering system.

2. Description of the Related Art As shown in the left half of FIG. 1, a ball in which an annular fastening metal fitting 219 is mounted in an annular fastening metal fitting mounting groove 217 formed on an outer peripheral side surface of a peripheral wall portion 213 of one end small opening 211 of a dust cover 209. As the seal structure of the dust cover for the joint,
1944 and so on.

Problems to be Solved by the Invention In the seal structure for the ball joint dust cover as described above, as shown in an enlarged view in the left half of FIG. 2, the tightening fitting 219 having an inner diameter of 200 A in the natural state is The inner diameter is expanded, and the dust cover 209 is mounted in the fastening metal fitting groove 217 by passing through the outer circumference of an outer peripheral lip 215 formed at the tip of the small opening portion 211 and having an outer diameter of 200C (200A <200C).

By the way, when a material having a high tear strength such as polyurethane is used to improve the tear strength of the dust cover 219, the hardness of the dust cover 209 also increases accordingly. Therefore, when the thickness of the peripheral wall portion 213 of the dust cover 209 small opening portion 211 is large, the fastening metal fitting 219
However, there is a problem that the elastic force of does not act on the inner peripheral surface of the small opening portion 211 of the dust cover 209.

As a countermeasure against this, the wall thickness of the peripheral wall portion 213 is reduced, that is, the fastening fitting groove 217 is deepened in the inner diameter direction of the ball stud 2 so that the tightening force of the fastening fitting 219 acts on the inner peripheral surface. It is possible. However, the tightening bracket mounting groove 21
When 7 is deep, outer peripheral lip 215 outer diameter 200C and tightening metal
The difference between the inner diameter A of 219 in the natural state and the outer diameter of the groove bottom 218 and the outer diameter 200B becomes large, and the expansion of the inner diameter when the fastening metal fitting 219 passes the outer periphery lip 215 exceeds the elastic limit. There is a drawback in that a desired tightening force cannot be obtained when the metal piece is mounted in the metal fitting mounting groove 217.

Means for Solving Problems A small opening at one end of the dust cover is attached to the outer circumference of the handle of the ball stud of the ball joint, and a large opening at the other end is attached to the outer circumference of the socket of the ball joint. In the seal structure, an annular fastening metal fitting mounting groove is formed on the end surface of the small opening of the dust cover opposite to the socket, and the fastening metal fitting is mounted in the fastening metal fitting mounting groove.

Action Since there is no obstacle that allows the fastening metal fitting to pass through until it is fitted into the fastening fitting fitting groove, the expansion of the inner diameter of the fastening fitting during mounting can be extremely reduced.

Example The configuration of an example of the present invention will be described below with reference to the drawings.

The right half of FIG. 1 shows a ball joint 1 having a sealing structure of a dust cover for a ball joint according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of FIG.

In FIG. 1, 2 is a ball stud, which has a ball head 4 at one end.
Is rotatably and slidably supported in the socket 6 through the bearing 5, and the handle 3 at the other end projects from the small opening 7 of the socket 6.

A dust cover 9 is formed of an elastic material in a substantially circular bell shape. One end small opening 11 of the dust cover 9 is attached to the outer periphery of the handle 3 of the ball stud 2, and the other end large opening 12
Is mounted in a dust cover groove 8 formed on the outer peripheral surface of the socket 6 near the small opening 7. Small opening 11 and large opening 12
An intermediate portion between and is formed in the body portion 10 which bulges in the outer diameter direction.

On the inner peripheral surface of the small opening 11 of the dust cover 9, there is formed an inner peripheral lip 14 composed of a plurality of circumferential projections that are elastically pressed against the outer peripheral surface of the handle 3 of the ball stud 2 to enhance sealing performance. There is. In addition, the outer peripheral surface of the small opening 11 has an outer peripheral lip that seals between a connecting member (not shown) such as a knuckle arm.
15 are formed.

On the end face 16 opposite to the socket of the dust cover 9 small opening 11,
An annular fastening metal fitting mounting groove 17 having a rectangular cross section and extending in the ball joint axial direction is formed. A thin peripheral wall portion 13 is interposed between the inner peripheral lip 14 and the fastening metal fitting mounting groove 17 described above. A single-winding circlip 19, which is a fastening metal fitting, is mounted in the fastening metal fitting groove 17. As shown in the right half of FIG. 2, assuming that the inner diameter of the circlip 19 in the natural state is A and the outer diameter of the peripheral wall portion 13 of the small opening 11 of the dust cover 9 is B, A <B. The clip 19 tightens and fixes the dust cover 9 to the handle 3 of the ball stud 2 with the tightness of this tightening margin.

Next, assembly of the above structure will be described. First, the ball stud ball head 4 surrounded by the bearing 5 is inserted into the socket 6 to assemble the ball joint 1.

Next, the large opening 12 of the dust cover 9 is mounted in the dust cover groove 8 of the socket 6, and the small opening 11 is press-fitted into the handle 3 of the ball stud 2. After that, as shown in the right half of FIG. 2, the diameter of the single winding circlip 19 is slightly increased by the diameter expanding jig 25 to a diameter C that allows the opening 20 of the fastening metal fitting mounting groove 17 to pass through. To do. Subsequently, the pushing jig 26 pushes the expanded single-wrap circlip 19 into the fastening metal fitting groove 17. At this time, the expansion of the inner diameter of the single-winding circlip 19 is performed within a range that does not exceed its elastic limit, so that the single-winding circlip does not lose its tightening force when mounted.

Next, another embodiment of the present invention will be described with reference to FIG. 3 showing the same portion as the right half portion of FIG. In the second embodiment, a lid 121 is formed on the opening 120 of the fastening fitting mounting groove 117. The lid 121 prevents water from entering the fastening fitting mounting groove 117.

In the above-mentioned first and second embodiments, the single-winding circlip as the fastening metal fitting may be in a multi-winding shape or an unbroken ring shape.

Effect As described above, according to the present invention, since there is no obstacle that allows the fastening metal fitting to pass through before being mounted in the fastening metal fitting mounting groove, it is possible to extremely reduce the expansion of the inner diameter of the fastening metal fitting during mounting. The expansion of the inner diameter is performed within the elastic range, so that the dust cover can be clamped and fixed to the handle of the ball stud with a desired tightening force.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional plan view showing the sealing structure of a conventional ball joint dust cover in the left half part and the right half part in which the sealing structure of the ball joint dust cover according to the first embodiment of the present invention is shown. . FIG. 2 is a partially enlarged explanatory view of the left half of the left half of FIG. 1 and the right half of the right half of FIG. FIG. 3 is an explanatory view of the right half portion and the same portion of FIG. 2 showing the second embodiment of the present invention. (Explanation of symbols) 1 ... Ball joint. 2 ... Ball stud. 3 ... pattern. 6 ... Socket. 9: Dust cover. 11 …… Tightening hardware. 12 ... Large opening. 16 …… An end surface on the side opposite to the socket. 17 …… Tightening fitting mounting groove. 19 ...... Tightening hardware.

Claims (1)

[Claims] 1. A small opening 11 on one end of a dust cover 9 is mounted on the outer circumference of a handle 3 of a ball stud 2 of a ball joint 1, and a large opening 12 on the other end is mounted on the outer circumference of a socket 6 of the ball joint 1. In the seal structure of the dust cover for the ball joint, the dust cover 9 small opening 11
A sealing structure for a ball joint dust cover, characterized in that an annular fastening metal fitting mounting groove 17 is formed on the end face 16 on the side opposite to the socket, and a fastening metal fitting 19 is mounted in the fastening metal fitting mounting groove 17.