JP2014181741A - Dust cover for ball joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a duct cover for a ball joint capable of suppressing occurrence of so-called opening phenomenon of a small-diameter opening portion, that is, disconnection of the small-diameter opening portion and a shaft even under a low temperature atmosphere, and having high sealability of the small-diameter opening portion.SOLUTION: In a dust cover 6 for a ball joint 3 in which a ball head portion 2 formed at one end of a ball stud 1 is held in a socket, a shaft 4 at the other end of the ball stud 1 is fastened and fixed to a knuckle 5, a large-diameter opening portion 8 at one end is fixed to and held on an outer peripheral surface of the socket 3, and a small-diameter opening portion 7 at the other end on which a reinforcement ring 9 made of a hard material is held by the shaft 4, the reinforcement ring 9 has a cylindrical inner peripheral face kept into contact with an outer peripheral face of the shaft 4, and an upper end face kept into contact with a lower face of the knuckle 5, the upper end face includes a first annular groove 93 opened toward the lower face, and a seal ring 94 made of a rubber elastic material is disposed in the first annular groove 93.

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. 7 is known as a ball joint to which a dust cover is attached for the purpose of dust-proofing and waterproofing the 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. 7, 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.

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 having a good seal performance at a part.

  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. In the ball joint dust cover, which is fixedly held on the outer peripheral surface of the socket and the other end small-diameter opening integrally formed with a hard material reinforcing ring is held on the shaft, the reinforcing ring is connected to the outer peripheral surface of the shaft. The cylindrical inner peripheral surface is in contact with the upper end surface in contact with the lower surface of the knuckle, and the upper end surface is provided with a first annular groove that opens toward the lower surface, and a rubber-like elastic member is provided in the first annular groove. A seal ring made of material is arranged.

The present invention has the following effects.
According to the dust cover for a ball joint of the first aspect of the present invention, the reinforcing ring formed integrally with the small-diameter opening at the other end has a cylindrical inner peripheral surface in contact with the outer peripheral surface of the shaft and an upper end surface in contact with the lower surface of the knuckle. In addition, the upper end surface is provided with a first annular groove that opens toward the lower surface of the knuckle, and a rubber-like elastic seal ring is disposed in the first annular groove. Even under the atmosphere, the contact between the small-diameter opening at the other end and the shaft can be prevented from being opened, and the opening of the small-diameter opening at the other end can be suppressed, and the sealing performance of the small-diameter opening at the other end can be maintained well.
Furthermore, according to the dust cover for a ball joint of the invention as set forth in claim 2, since the seal ring disposed in the first annular groove of the reinforcing ring is made of a silicone rubber material, the other end also in a low temperature atmosphere. The sealing performance of the small-diameter opening is not reduced.

Furthermore, according to the dust cover for a ball joint of the invention described in claim 3, the reinforcing ring is arranged in a ferrule ring made of a metal material having a U-shaped cross section that is fitted and fixed to the outer peripheral surface of the shaft. Therefore, the axial movement of the small-diameter opening at the other end can be restricted, and the sealing performance at the small-diameter opening at the other end can be further enhanced.
Furthermore, according to the dust cover for a ball joint of the invention described in claim 4, the cylindrical inner peripheral surface and the lower end surface of the reinforcing ring are made of a metal material having an L-shaped cross section that is fitted and fixed to the outer peripheral surface of the shaft. Since the structure is in contact with the retainer, the axial movement of the other end small-diameter opening can be restricted, and the sealing performance of the other end small-diameter opening can be further enhanced.

  Furthermore, according to the dust cover for a ball joint according to the fifth aspect of the present invention, the seal member made of rubber-like elastic material is disposed in the second annular groove provided on the lower end surface of the reinforcing ring. It is possible to more reliably suppress leakage of grease inside.

The longitudinal cross-sectional view of the dust cover for ball joints of the 1st aspect based on this invention. The elements on larger scale of FIG. The longitudinal cross-sectional view before mounting | wearing with the dust cover shown in FIG. The longitudinal cross-sectional view before mounting | wearing with the dust cover of the 2nd aspect based on this invention. The longitudinal cross-sectional view before mounting | wearing with the dust cover of the 3rd aspect based on this invention. The longitudinal cross-sectional view before mounting | wearing with the dust cover of the 4th aspect based on this invention. The longitudinal cross-sectional view of the dust cover for ball joints based on a prior art.

Hereinafter, a first mode for carrying out the present invention will be described.
As shown in FIGS. 1, 2, and 3, 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 other end shaft 4 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 small-diameter opening 7 integrally formed with a reinforcing ring 9 made of hard material is formed. A basic configuration held on the shaft 4 is provided.

  The reinforcing ring 9 formed integrally with the small-diameter opening 7 at the other end of the dust cover 6 has a cylindrical inner peripheral surface 91 in contact with the outer peripheral surface 41 of the shaft 4 and an upper end surface 92 in contact with the lower surface 51 of the knuckle 5. The upper end surface 92 includes a first annular groove 93 that opens toward the lower surface 51 of the knuckle 5, and a rubber ring elastic seal ring 94 is disposed in the first annular groove 93. It has become.

A dust seal 61 that is in elastic contact with the lower surface 51 of the knuckle 5 is integrally formed in the other end small-diameter opening 7.
Due to the presence of the dust seal 61, it is possible to effectively prevent the entry of dust, earth and sand from the outside into the dust cover 6.

As the material of the seal ring 94, various rubber-like elastic materials can be used, and a silicone rubber material excellent in low temperature characteristics is particularly preferable.
Further, the shape of the seal ring 94 is not limited to the O-ring shape, and a square ring, an X ring, or the like is appropriately selected and used.

Further, as the material of the reinforcing ring 9, a metal material or a resin material is appropriately selected and used, but a resin material is preferable in consideration of sliding resistance with the shaft 4.
The shape of the reinforcing ring 9 does not necessarily have a rectangular cross section as shown in the figure, and the first annular groove 93 that opens toward the lower surface 51 of the knuckle 5 and the cylinder that contacts the outer peripheral surface 41 of the shaft 4. If it has the shape inner peripheral surface 91, it is applicable.

  In this way, the reinforcing ring 9 made of hard material integrally formed in the other end small-diameter opening 7 of the dust cover 6 is in contact with the cylindrical inner peripheral surface 91 in contact with the outer peripheral surface 41 of the shaft 4 and the lower surface 51 of the knuckle 5. The upper end surface 92 includes a first annular groove 93 that opens toward the lower surface 51 of the knuckle 5, and a seal ring made of a rubber-like elastic material is provided in the first annular groove 93. 94 is arranged, so that even in a low-temperature atmosphere, the contact between the other end small-diameter opening 7 and the shaft 4 is disengaged. The sealing performance of the part 7 is maintained well.

  Further, a sealing agent such as liquid rubber is applied to the fitting surface between the ball stud 1 and the knuckle 5 to reliably suppress leakage of grease and intrusion of muddy water from the fitting surface.

Next, a second mode for carrying out the present invention will be described with reference to FIG.
The difference from the first aspect described above is that the reinforcing ring 9 is arranged in a ferrule ring 95 made of a metal material having a U-shaped cross section that is fitted and fixed to the outer peripheral surface 41 of the shaft 4. .
Accordingly, the seal ring 94 made of rubber-like elastic material does not contact the lower surface 51 of the knuckle 5 but contacts the upper flange portion of the ferrule ring 95.

  In this way, the ferrule ring 95 is securely fitted and fixed to the outer peripheral surface 41 of the shaft 4 and the reinforcing ring 9 is held in the ferrule ring 95. By restricting the movement in the axial direction, the sealing performance at the other end small-diameter opening 7 can be further enhanced.

Next, a third mode for carrying out the present invention will be described with reference to FIG.
The difference from the first embodiment described above is that the cylindrical inner peripheral surface 91 and the lower end surface 97 of the reinforcing ring 9 are fitted and fixed to the outer peripheral surface 41 of the shaft 4 and are made of a metal material having an L-shaped cross section. 96 is in contact with.
Further, the seal ring 94 made of rubber-like elastic material arranged in the first annular groove 93 is not an O-ring shape but an X ring shape.

  In this way, the retainer 96 is securely fitted and fixed to the outer peripheral surface 41 of the shaft 4, and the reinforcing ring 9 is restricted from moving in the axial direction by the retainer 96. The sealing performance can be further improved.

Next, a fourth mode for carrying out the present invention will be described with reference to FIG.
The difference from the third aspect described above is that a second annular groove 98 is provided in the lower end surface 97 of the reinforcing ring 9, and a seal member 99 made of a rubber-like elastic material is disposed in the second annular groove 98. This is the point.
Also, the shape of the rubber-like elastic seal ring 94 disposed in the first annular groove 93 is not an X ring shape but a square ring with a square cross section.
Due to such a configuration, the leakage of grease in the dust cover 6 can be more reliably suppressed.

  The material of the dust cover 6 is appropriately selected from a rubber-like elastic material such as chloroprene and a thermoplastic elastomer such as a polyester-based elastomer and a thermoplastic polyurethane.

  The dust cover 6 is filled with grease.

On the other hand, the one end large-diameter opening 8 having a substantially U-shaped cross section of the dust cover 6 is fixed and held by an annular pressing ring 11 in an annular groove 31 formed on the outer peripheral surface of the socket 3. Yes.
Although the circlip having a substantially rectangular cross section is used as the pressing ring 11, various pressing rings are used depending on applications such as a type in which a metal reinforcing ring is embedded and integrated in the large-diameter opening 8 at one end.

  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 8 One end large diameter opening 9 Reinforcement ring 11 Press ring 31 Groove 41 Outer surface 51 Lower surface 61 Dust seal 91 Inner surface 92 Upper end surface 93 First annular groove 94 Seal ring 95 Ferrule ring 96 Retainer 97 Lower end surface 98 Second annular groove 99 Seal member

Claims (5)

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 fixedly held on the outer peripheral surface of the socket (3), and the other end small-diameter opening (7) integrally formed with a hard material reinforcing ring (9) is the shaft (4). In the ball joint dust cover (6) held by
The reinforcing ring (9) has a cylindrical inner peripheral surface (91) in contact with the outer peripheral surface (41) of the shaft (4) and an upper end surface (92) in contact with the lower surface (51) of the knuckle (5). The upper end surface (92) includes a first annular groove (93) that opens toward the lower surface (51), and a rubber-like elastic seal ring (93) is formed in the first annular groove (93). 94) is disposed, and the dust cover for ball joints.   The dust cover for a ball joint according to claim 1, wherein the seal ring (94) is made of a silicone rubber material.   The reinforcing ring (9) is disposed in a ferrule ring (95) made of a metal material having a U-shaped cross section that is fitted and fixed to the outer peripheral surface (41) of the shaft (4). The dust cover for ball joints according to claim 1 or 2.   The cylindrical inner peripheral surface (91) and the lower end surface (97) of the reinforcing ring (9) are made of a metal material having an L-shaped cross section that is fitted and fixed to the outer peripheral surface (41) of the shaft (4). The dust cover for a ball joint according to claim 1 or 2, wherein the dust cover is in contact with the retainer (96).   The rubber-like elastic sealing member (99) is disposed in a second annular groove (98) provided in the lower end surface (97) of the reinforcing ring (9). Or the dust cover for ball joints of 4.

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