JP2011106478A - Dust cover for ball joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dust cover for a ball joint which prevents a seal lip and dust lip from being worn and broken at an early stage due to lack of grease even in long term utilization and exhibits sealing performance stable over a long period. <P>SOLUTION: A dust cover for the ball joint made of a rubber-like elastic material forces a spherical head part formed on one end of a ball stud to be held in a socket, a shaft part on the other end of the ball stud to be fastened and fixed to a knuckle, one end large diameter opening part to be fixed and held on an outer peripheral surface of the socket, the other end small diameter opening part to be held by the shaft part and a film part for connecting the large diameter opening part and small diameter opening part, wherein a grease reservoir is provided to the inside on the small diameter opening part side of the film part. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a dust cover for a ball joint.
The present invention also relates to a ball joint dust cover used for an automobile suspension device, a steering device, and the like.

  Conventionally, a ball joint dust cover shown in FIG. 4 is known as a ball joint to which a dust cover is attached for the purpose of dustproofing and waterproofing the ball joint joint. (Patent Documents 1 and 2)

In this kind of ball joint dust cover sealing structure, a ball head 200 formed at one end of the ball stud 10 is held in a socket 300.
The shaft 400 at the other end of the ball stud 10 is fastened and fixed to the knuckle 500.
On the other hand, one end large-diameter opening 800 of the dust cover 600 made of rubber-like elastic material is fixedly held by the snap ring 220 on the outer peripheral surface of the socket 300, and the other end small-diameter opening 150 in which the metal reinforcing ring 110 is embedded is a shaft. The configuration is held by the unit 400.

  In this type, the small-diameter opening 150 of the conventional dust cover 600 has a lower surface of the knuckle 500 for preventing water and dust from entering the dust cover 600 and preventing grease from flowing out of the dust cover 600 to the outside. The dust lip 100 and the grease in the dust cover 600 do not leak to the outside so that a seal lip is provided in close contact with the outer peripheral surface of the shaft portion 400.

On the other hand, the large-diameter opening 800 is completely fixed and held by the snap ring 220 on the outer peripheral surface of the socket 300, but the small-diameter opening 150 is not completely fixed, and the stud 10 and the knuckle 500 are swung. In order to prevent the dust cover 600 from being twisted with the rotational motion, the stud 10 and the knuckle 500 are sealed while sliding.
Thus, since the seal lip provided in the small-diameter opening 150 and the dust lip 100 are slippery, grease is interposed from the dust lip to the periphery of the seal lip, and these parts are worn by rubbing against the knuckle 500 and the ball stud 10. It is desirable to prevent this.

Therefore, grease is normally applied to the seal lip and the dust lip 100.
However, when used for a long period of time, there was a problem that the grease was insufficient, and the seal lip and 100 parts of the dust lip were worn or cut off.
As a result, the functions of the dust lip 100 and the seal lip are impaired, allowing dust and water to enter the dust cover 600, and at the same time, causing the problem of leaking the grease in the dust cover 600 to the outside.

Japanese Utility Model Publication No. 4-32313 JP 2004-92776 A

  The present invention has been made in view of such problems, and even when used for a long period of time, there is no problem that the grease is insufficient and the seal lip or dust lip wears out or breaks off at an early stage. An object of the present invention is to provide a ball joint dust cover that exhibits stable sealing performance.

  In the dust cover for ball joint according to the present invention, the ball head formed at one end of the ball stud is held in the socket, and the shaft portion at the other end of the ball stud is fastened and fixed to the knuckle. Is fixed and held on the outer peripheral surface of the socket, the other end small diameter opening portion is held on the shaft portion, and a rubber-like elastic material provided with a film portion connecting the large diameter opening and the small diameter opening In the dust cover for ball joint, a grease reservoir is provided inside the membrane portion on the small diameter opening side.

The present invention has the following effects.
According to the dust cover for a ball joint of the first aspect of the present invention, even when used for a long period of time, the grease is insufficient, and there is no problem that the seal lip or dust lip wears or breaks early, and it is stable for a long time. Seal performance can be demonstrated.
Furthermore, according to the dust cover for a ball joint of the invention described in claim 2, since it can be integrally formed with the dust cover, the molding process is easy.

Furthermore, according to the dust cover for a ball joint according to the third aspect of the invention, the grease can be supplied smoothly following the displacement of the small-diameter opening.
Furthermore, according to the dust cover for a ball joint of the invention described in claim 4, the conventional dust cover can be used as it is.

The longitudinal cross-sectional view of the dust cover for ball joints based on this invention. The principal part enlarged view of FIG. The figure which showed other embodiment similarly to FIG. The longitudinal cross-sectional view of the dust cover for ball joints based on a prior art.

Hereinafter, modes for carrying out the present invention will be described.
As shown in FIGS. 1 and 2, the ball joint dust cover according to the present invention has a ball head 2 formed at one end of a ball stud 1 held in a socket 3, The shaft portion 4 at the end is fastened and fixed to the knuckle 5, one end large-diameter opening 8 is fixed and held on the outer peripheral surface of the socket 3 by a snap ring 22, and the other end small-diameter opening portion 15 is fixed to the shaft portion 4 within a certain range. A dust strip 10 that is held in such a manner as to allow sliding movement in the direction, and is in sealing contact with the lower surface of the knuckle 5 to prevent water and dust from entering the ball joint on the small diameter opening 15 side, Since the grease in the dust cover 6 does not leak to the outside, a seal lip 7 that is in close contact with the outer peripheral surface of the shaft portion 4 is provided.
In addition, a film portion 7 that connects the large-diameter opening 8 and the small-diameter opening 15 is disposed.
Further, a grease reservoir 71 is formed inside the membrane portion 7 on the small diameter opening 15 side.

The grease reservoir 71 is formed by a partition member 711 extending from the film portion 7 toward the outer peripheral surface of the shaft portion 4.
As a result, the dust cover 6 is deformed as the ball stud 1 and the knuckle 5 swing and rotate, and the grease in the grease reservoir 71 is supplied to the dust lip 10 and the seal lip 9.

The partition member 711 is provided so as to extend integrally from the film portion 7, and the tip thereof may be in contact with the outer peripheral surface of the shaft portion 4 or may be opposed to the narrow gap, but is in contact with the shaft portion 4. As a result, the grease in the grease reservoir 71 can be reliably stored for a long period of time.
Further, the partition member 711 may be formed to extend from the lower surface 151 of the small diameter opening 15 toward the outer peripheral surface of the shaft portion 4.
In such an embodiment, the grease can be smoothly supplied to the dust lip 10 and the seal lip 9 following the displacement of the small-diameter opening.

Next, another embodiment of the present invention will be described with reference to FIG.
The difference from the above-described aspect is that the partition member 712 extends from the outer peripheral surface toward the film portion 7.
As the material of the partition member 712, a wide range of materials such as rubber, resin, metal and the like can be used.
The partition member 712 may be formed integrally with the shaft portion 4 or may be provided so as to be fitted to the outer peripheral surface of the shaft portion 4 later.
As a result, the conventional dust cover can be used as it is.

A metal reinforcing ring 11 is embedded in the small diameter opening 15.
The metal reinforcing ring 11 gives rigidity to the small diameter opening 15 and prevents excessive deformation of the small diameter opening 15 even when the inclination angle of the ball stud 1 with respect to the socket 3 is large (when the swing angle is large). ing.
Further, a seal lip 9 that is in elastic contact with the outer peripheral surface of the shaft portion 15 is formed on the inner peripheral surface of the small-diameter opening 15.
The seal lip 9 prevents the grease in the dust cover 6 from leaking to the outside.

Further, a dust seal 10 that is in elastic contact with the lower end surface of the knuckle 5 is formed on the upper end surface of the small-diameter opening 15.
The presence of the dust seal 10 can prevent water and earth and sand from entering the dust cover 6.

  Further, the present invention is not limited to the best mode for carrying out the invention described above, and various other configurations can be adopted without departing from the gist of the present invention.

  It can be used for ball joints used in automobile suspension systems and steering systems.

DESCRIPTION OF SYMBOLS 1 Ball stud 2 Ball head 3 Socket 4 Shaft part 5 Knuckle 6 Dust cover 7 Film part 8 Large diameter opening part 9 Seal lip 10 Dust seal 11 Metal reinforcement ring 15 Small diameter opening part 71 Grease pool part 711 Partition member 712 Partition member

Claims (4)

A ball head (2) formed at one end of the ball stud (1) is held in the socket (3),
The shaft (4) at the other end of the ball stud (1) is fastened and fixed to a knuckle (5), one end large-diameter opening (8) is fixedly held on the outer peripheral surface of the socket (3), and the other end has a small diameter. A rubber-like elasticity provided with a membrane part (7) that holds the opening part (15) on the shaft part (4) and connects the large-diameter opening part (8) and the small-diameter opening part (15). A dust cover for ball joints made of a material, wherein a grease reservoir (71) is provided inside the membrane part (7) on the small diameter opening (15) side.   The ball joint according to claim 1, wherein the grease reservoir (71) is formed by a partition member (711) extending from the film portion (7) toward the outer peripheral surface of the shaft portion (4). Dust cover.   The grease reservoir (71) is formed by a partition member (711) extending from the lower surface (151) of the small diameter opening (15) toward the outer peripheral surface of the shaft (4). Item 2. A dust cover for a ball joint according to Item 1.   The ball joint according to claim 1, characterized in that the grease reservoir (71) is formed by a partition member (712) extending from the outer peripheral surface of the shaft portion (4) toward the film portion (7). Dust cover.

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