JP2014219045A - Dust cover for ball joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust cover for a ball joint capable of restraining such a small-diameter opening phenomenon that contact of a small-diameter opening and a shaft is cancelled even under a low-temperature atmosphere, and having a sufficient sealing performance of the small-diameter opening and a durability performance of a film part.SOLUTION: A duct cover for a ball joint comprises: a rubber-like elastic material lip part, in which a head bulb formed at one end of a ball stud is held in a socket, a shaft at the other end of the ball stud is fastened and fixed to a knuckle, a large-diameter opening at one end is held on an outer periphery of the socket, a small-diameter opening at the other end in which a reinforcing ring is embedded is held by the shaft, and an inner periphery of the reinforcing ring is integrally molded, and that closely contacts the shaft outer periphery relatively slidably; and a rubber-like elastic material film part for coupling the large-diameter opening at one end and the small-diameter opening at the other end. The film part and the lip part are formed of different rubber-like elastic materials.

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.

  2. Description of the Related Art Conventionally, a ball joint dust cover shown in FIG. 5 is known as a ball joint to which a dust cover is attached for the purpose of dust prevention and waterproofing of a ball joint joint. (Patent Document 1)

In this kind of ball joint dust cover sealing structure, a ball head 200 formed at one end of a ball stud 100 is held in a socket 300.
The shaft 400 at the other end of the ball stud 100 is fastened and fixed to the knuckle 500.
On the other hand, one end large-diameter opening 800 having a substantially U-shaped cross section of the dust cover 600 made of an elastic material is fixed and held in an annular groove 310 formed on the outer peripheral surface of the socket 300 by an annular pressing ring 700. The other end small-diameter opening 150 in which the L-shaped metal reinforcing ring is embedded is held by the shaft 400. The rubber existing between the metal reinforcing ring and the shaft 400 is appropriately compressed, and exhibits a sealing property against the swinging motion of the ball stud 100 due to the repulsive force (tightening force) and followability of the rubber. It takes a shape to do.

However, this type of conventional dust cover 600 made of an elastic material swings in a state where the ball stud 100 is inclined as shown in FIG. 5, on the side where the film portion of the dust cover 600 made of an elastic material extends (the right side in the figure). Since the force that stretches the small diameter opening 150 is applied, the contact between the lip portion of the small diameter opening 150 and the knuckle 500 is released, and a so-called opening phenomenon of the small diameter opening 150 occurs.
As a result, the sealing performance at the small-diameter opening 150 is lowered, and the problem that earth and sand and dust enter the dust cover 600 from the outside is caused.

  In particular, the rubber constituting the dust cover 600 made of an elastic material loses its elasticity in a low temperature atmosphere, and the followability of the film portion with respect to the swinging motion of the ball joint is reduced. As a result, the opening phenomenon in which the seal lip portion separates from the shaft 400. It was found that the problem occurred.

  In addition, when such a mouth opening phenomenon occurs, not only earth and sand and dust enter the dust cover 600 from the outside, but also there is a risk that the grease enclosed in the dust cover 600 leaks out.

  In particular, with a single type of material, the ozone resistance, grease resistance, water resistance, etc. required for the film portion of the dust cover 600 and the sealing performance required for the seal lip portion of the small-diameter opening 150 are compatible. It was difficult to plan.

JP 62-137408 A

  The present invention has been made in view of such a problem, and even in a low-temperature atmosphere, the contact between the small-diameter opening and the shaft is released, and the occurrence of the so-called opening phenomenon of the small-diameter opening is suppressed, and the small-diameter opening An object of the present invention is to provide a dust cover for a ball joint in which both the sealing performance of the portion and the durability performance of the membrane portion are good.

  In the dust cover for a ball joint according to the present invention, the ball head formed at one end of the ball stud is held in the socket, the shaft at the other end of the ball stud is fastened and fixed to the knuckle, and the large-diameter opening is at the one end. The other end small-diameter opening, which is held on the outer peripheral surface of the socket and in which the reinforcing ring is embedded, is held by the shaft, is integrally formed on the inner peripheral surface of the reinforcing ring, and is hermetically contacted so as to be slidable relative to the outer peripheral surface of the shaft. A dust cover for a ball joint comprising: a lip portion made of a rubber-like elastic material; and a film portion made of a rubber-like elastic material connecting the one end large-diameter opening and the other end small-diameter opening; The film part and the lip part are formed of different rubber-like elastic materials.

The present invention has the following effects.
According to the dust cover for a ball joint of the first aspect of the present invention, since the film portion and the lip portion are formed of different rubber-like elastic materials, the contact between the small-diameter opening and the shaft is released even in a low temperature atmosphere. In addition to suppressing the occurrence of the so-called opening phenomenon of the small-diameter opening, the sealing performance of the small-diameter opening and the durability of the membrane part are good.

Furthermore, according to the dust cover for a ball joint of the invention described in claim 2, since the membrane portion and the lip portion are integrally formed in a state where they are separated by the reinforcing ring, the molding can be performed efficiently.
Furthermore, according to the dust cover for a ball joint of the invention described in claim 3, the reinforcing ring is divided, and the outer peripheral side reinforcing ring formed integrally with the membrane part has the inner peripheral surface integrally formed with the lip part. Since the side reinforcing ring is fitted, various combinations of the film part and the lip part can be easily performed according to the intended use.

The longitudinal cross-sectional view of the state which mounted | wore with the dust cover for ball joints of the 1st aspect which concerns on this invention. The longitudinal cross-sectional view before mounting | wearing with the dust cover for ball joints shown in FIG. The longitudinal cross-sectional view before mounting | wearing with the dust cover for ball joints of the 2nd aspect which concerns on this invention, and before an assembly. The longitudinal cross-sectional view of the state which assembled the dust cover for ball joints shown in FIG. The longitudinal cross-sectional view of the dust cover for ball joints based on a prior art.

Hereinafter, each mode for carrying out the present invention will be described.
As shown in FIGS. 1 and 2, the ball joint dust cover according to the first aspect of the present invention has a ball head 2 formed at one end of a ball stud 1 held in a socket 3. The shaft 4 at the other end of the stud 1 is fastened and fixed to the knuckle 5, one end large-diameter opening 8 is held on the outer peripheral surface of the socket 3, and the other end small-diameter opening 7 embedded with a reinforcing ring 71 is held on the shaft 4. A lip portion 72 made of a rubber-like elastic material which is integrally formed on the inner peripheral surface of the reinforcing ring 71 and is in sealing contact with the outer peripheral surface of the shaft 4 so as to be relatively slidable; A basic configuration comprising a film portion 9 made of a rubber-like elastic material connecting the small-diameter openings 7 is provided.

And the film part 9 and the lip part 72 have the characteristics shape | molded by the different rubber-like elastic material.
As the rubber-like elastic material used for the membrane part 9, rubber materials such as chloroprene having excellent grease resistance and ozone resistance, polyester elastomers having high mechanical strength, thermoplastic elastomers such as thermoplastic polyurethane, etc. are suitably used. Select and use.
Further, as the rubber-like elastic material used for the lip portion 72, silicone rubber having good low temperature characteristics, fluorine rubber having good heat resistance, or the like is appropriately selected and used.

As described above, since the film portion 9 and the lip portion 72 are formed of different rubber-like elastic materials, the contact between the small diameter opening 7 and the shaft 4 is released even in a low temperature atmosphere. While suppressing the occurrence of the opening phenomenon, both the sealing performance of the small-diameter opening 7 and the durability performance of the membrane portion 9 are good.
Since these two different types of rubber-like elastic materials exist in a state where the film portion 9 and the lip portion 72 are separated by the reinforcing ring 71, they can be integrally molded at the same time.
For this reason, shaping can be performed efficiently.

Next, a ball joint dust cover according to a second embodiment for carrying out the present invention will be described.
As shown in FIGS. 3 and 4, the difference from the ball joint dust cover of the first aspect described above is that the reinforcing ring 71 is divided into two parts, and the outer side reinforcing ring 711 formed integrally with the membrane portion 9. Further, the inner peripheral side reinforcing ring 712 integrally formed with the lip portion 72 is fitted and integrated on the inner peripheral surface thereof.
As shown in FIG. 3, first, a lip portion formed integrally with an inner peripheral surface of an inner peripheral side reinforcing ring 712 having an L-shaped cross section with silicone rubber having good low-temperature characteristics, fluorine rubber having good heat resistance, or the like. 72 and an outer peripheral surface and an end surface of the outer peripheral side reinforcing ring 711 having an L-shaped cross section are integrally formed of a rubber material such as chloroprene, a polyester elastomer having a high mechanical strength, a thermoplastic elastomer such as a thermoplastic polyurethane, or the like. After the film portions 9 are separately manufactured, as shown in FIG. 4, the inner peripheral side reinforcing ring 712 and the outer peripheral side reinforcing ring 711 are fitted and integrated to form the dust cover 6.

When this fitting is integrated, the inner peripheral side reinforcing ring 712 and the outer peripheral side reinforcing ring 711 can be more firmly joined by interposing an adhesive on the joint surface between the inner peripheral side reinforcing ring 712 and the outer peripheral side reinforcing ring 711. .
With such a configuration, various combinations of the film portion 9 and the lip portion 72 can be easily performed according to the intended use.

Further, as the material of the reinforcing ring 71, a metal material or a resin material is appropriately selected and used.
The shape of the reinforcing ring 71 is not necessarily a rectangular shape as shown in the figure, and an L-shape or the like is applicable.

  The dust cover 6 is filled with grease.

  The one-end large-diameter opening 8 has a substantially U-shaped cross section and is fixed and held by an annular pressing ring 81 in an annular groove 310 formed on the outer peripheral surface of the socket 3.

  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 stat 2 Ball head 3 Socket 4 Shaft 5 Knuckle 6 Dust cover 7 Other end small diameter opening part 8 One end large diameter opening part 9 Film | membrane part 71 Reinforcement ring 72 Lip part 81 Washer 310 Annular groove part 711 outer periphery side reinforcement ring 712 inside Circumference reinforcement ring

Claims (3)

The ball head (2) formed at one end of the ball stud (1) is held in the socket (3), and the shaft (4) at the other end of the ball stud (1) is fastened and fixed to the knuckle (5). The one end large diameter opening (8) is held on the outer peripheral surface of the socket (3), the other end small diameter opening (7) embedded with a reinforcing ring (71) is held on the shaft (4), A lip portion (72) made of a rubber-like elastic material that is integrally formed on the inner peripheral surface of the reinforcing ring (71) and is in sealing contact with the outer peripheral surface of the shaft (4) so as to be relatively slidable; In a dust cover (6) for a ball joint comprising a part (8) and a film part (9) made of a rubber-like elastic material connecting the other end small-diameter opening (7),
The dust cover for a ball joint, wherein the film part (9) and the lip part (72) are formed of different rubber-like elastic materials.   The dust cover for a ball joint according to claim 1, wherein the membrane portion (9) and the lip portion (72) are integrally formed in a state where they are separated by the reinforcing ring (71).   The reinforcing ring (71) is divided into two parts, and the outer circumferential side reinforcing ring (711) integrally formed with the membrane part (9) is integrally molded with the inner peripheral surface of the lip part (72). The dust cover for a ball joint according to claim 1, wherein a ring (712) is fitted.

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