JP2016008629A - Dust cover for ball joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust cover for a ball joint which can secure stable seal performance without causing the initial wear of a dust cover film part, and the excessive wear of a lip part even if the dust cover is in a variety of use environments.SOLUTION: In a dust cover 6 for a ball joint in which a ball head part 2 fixed to one end of a ball stud 1 is held in a socket 3, a shaft 4 at the other end of the ball stud is caulked and fixed to a knuckle 5, a one-end large-diameter opening part 8 is fixed and held to an external peripheral face of the socket, and the other end small-diameter opening part 7 is held to a shaft side, a bearing 9 is fixed and held to the other end small-diameter opening part, an inner race of the bearing is fit and fixed on an external peripheral face of the shaft, and an outer race of the bearing is integrated with the other end small-diameter opening part.

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. 6 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 performance against the swinging motion of the ball stud 100 due to the repulsive force (tightening force) and followability of the rubber. Takes shape.

As shown in FIG. 6, this type of conventional elastic dust cover 600 swings with the ball stud 100 tilted to prevent water and dust from entering the ball joint, and from the ball joint. Prevents grease from flowing out.
Therefore, in order to ensure good sealing performance that prevents water and dust from entering and grease from flowing out, the other end small-diameter opening 150 is pressed against the knuckle 500 with a strong force, and the shaft 400 has a large size. Tension was necessary.

However, an excessive pressing force and a pressing force cause an excessive sliding resistance between the other end small-diameter opening 150 of the dust cover 600 and the knuckle 500 and the shaft 400.
As a result, excessive torsional stress is generated in the dust cover 600, and the film portion of the dust cover 600 is damaged at an early stage, or the lip portion provided in the other end small-diameter opening 150 causes excessive wear.

  Further, at the time of extremely low temperature (around -40 ° C.), the elasticity of the rubber is lost, so that there is a possibility that problems affecting the sealing properties such as opening of the lip portion due to deterioration of the followability of the film portion may occur.

JP 62-137408 A

  The present invention has been made in view of such a problem, and even under various usage environments, stable dust sealing is achieved without causing early damage of the dust cover film portion or excessive wear of the lip portion. An object of the present invention is to provide a dust cover for a ball joint that can be secured.

  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 ball joint dust cover is fixedly held on the outer peripheral surface of the socket and the other end small-diameter opening is held on the shaft side, and a bearing is fixedly held in the other end small-diameter opening, and the inner race of the bearing is The outer race of the shaft is fitted and fixed on the outer peripheral surface of the shaft, and the outer race of the bearing is integrated with the small-diameter opening at the other end.

The present invention has the following effects.
According to the dust cover for a ball joint according to the first aspect of the present invention, the bearing is fixedly held in the small-diameter opening at the other end, and the inner race of the bearing is directly fixed to the outer peripheral surface of the shaft. But it follows the movement of the shaft. Therefore, it is possible to avoid deterioration of the sealing performance of the lip portion due to insufficient swingability of the film portion at the time of a large swing angle or extremely low temperature, which is a concern in the prior art.
In addition, the shaft can be rotated smoothly with bearings, and excessive torsional stress can be avoided in the dust cover, and there is no sliding part between the shaft outer peripheral surface and the rubber material of the other end small diameter opening. It is possible to provide a ball joint dust cover that can secure a stable sealing property without causing early damage of the dust cover film part and excessive wear of the lip part even in the use environment.
Furthermore, according to the dust cover for a ball joint of the invention described in claim 2, since the dust lip is formed in the small-diameter opening at the other end so as to be in sealing contact with the knuckle, water and dust can enter the bearing side. It can be effectively prevented.

Furthermore, according to the dust cover for a ball joint of the invention of claim 3, since the outer race of the bearing is configured to be fitted and fixed to a reinforcing ring made of a hard material integrally formed with the other end small diameter opening, The manufacturing cost can be reduced and it is easy to respond to specification changes.
Further, according to the dust cover for a ball joint of the invention as claimed in claim 4, since the bearing seal is attached to the bearing, the waterproof and dustproof properties can be further improved, and the dust lip that sealably slides with the knuckle is also provided. In contrast, since it is less likely to be damaged by wear, good sealing performance can be maintained over a long period of time.

The longitudinal cross-sectional view of the dust cover for ball joints concerning the 1st embodiment of the present invention. The longitudinal cross-sectional view before mounting | wearing with the dust cover shown in FIG. The figure which showed the dust cover which concerns on the 2nd embodiment of this invention similarly to FIG. The figure which showed the dust cover which concerns on the 3rd embodiment of this invention similarly to FIG. The partial expanded longitudinal cross-sectional view which showed the dust cover which concerns on the 4th embodiment of this invention. The longitudinal cross-sectional view of the dust cover for ball joints based on a prior art.

Hereinafter, embodiments for carrying out the present invention will be described.
As shown in FIGS. 1 and 2, the ball joint dust cover 6 according to the first embodiment 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 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 is held on the shaft 4 side. It has a configuration.

A bearing 9 is fixedly held in the other end small-diameter opening 7 of the dust cover 6, an inner race 91 of the bearing 9 is fitted and fixed on the outer peripheral surface of the shaft 4, and an outer race 92 of the bearing 9 is fixed. The other end has a feature of being integrated with the small-diameter opening 7.
Thus, since the dust cover 6 is held on the shaft 4 side via the bearing 9, even if the shaft 4 rotates, this rotational movement can be smoothly performed in the bearing 9.

  As a result, even if the shaft 4 rotates, no excessive torsional stress is generated in the film portion of the dust cover 6, so that the film portion is not damaged for a long time.

In the first embodiment, the other end small-diameter opening 7 of the dust cover 6 is bonded and integrated to the outer race 92 of the bearing 9 at a stage after the dust cover 6 made of rubber-like elastic material is formed. .
In addition, bearing seals 93 are attached to both sides (upper and lower in the figure) of the bearing 9 to prevent water and dust from entering the ball joint and to effectively prevent grease from flowing out of the ball joint. Can be prevented.

Further, the bearing seal 93 is less likely to be damaged by wear unlike the dust lip that slides tightly with the knuckle 5, so that a good sealing performance can be maintained over a long period of time.
Therefore, the presence of the bearing seal 93 prevents water and dust from entering the ball joint and effectively prevents the grease from flowing out of the ball joint even in the absence of the dust lip. I can do it.

  Moreover, although the ball bearing was used for the bearing 9, a roll bearing etc. can also be used.

  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.

Next, a ball joint dust cover 6 according to a second embodiment of the present invention will be described with reference to FIG.
The difference from the first embodiment described above is that a dust lip 71 is formed in the other end small-diameter opening 7 of the dust cover 6 in place of the bearing seal 93 used in the first embodiment. .

The dust lip 71 has a truncated cone shape whose diameter increases toward the knuckle 5 side (upper side in the drawing).
When the dust cover 6 for the ball joint according to the second embodiment is assembled as shown in FIG. 1, the dust lip 71 comes into elastic contact with the side surface (upper and lower surfaces in the figure) of the knuckle 5 and external balls It is possible to effectively prevent water and dust from entering the joint.

Next, a ball joint dust cover 6 according to a third embodiment of the present invention will be described with reference to FIG.
The difference from the second embodiment described above is that the outer race 92 of the bearing 9 is integrally formed with the small-diameter opening 7 at the other end of the cylindrical portion of the reinforcing ring 72 having a L-shaped cross section made of hard material. This is a point that is fitted and fixed to the inner peripheral surface.

  As the material of the reinforcing ring 72, various metal materials are appropriately selected and used.

  Thus, since the outer race 92 of the bearing 9 is fitted and fixed to the reinforcing ring 72 formed integrally with the small-diameter opening 7 at the other end, the bearing 9 is attached to the dust cover 6 after the dust cover 6 is formed. Can be attached.

  For this reason, the manufacturing cost can be suppressed and the response to the specification change is easy.

Next, a ball joint dust cover 6 according to a fourth embodiment of the present invention will be described with reference to FIG.
The difference from the third embodiment described above is that a bearing seal 93 is attached to the bearing 9 with the dust lip 71 being present.

  The bearing seals 93 are provided on both sides (upper and lower in the drawing) of the bearing 9, but may be present only on the upper side (knuckle 5 side) in the drawing.

  For this reason, even when the dust lip 71 is damaged and does not function, it is possible to prevent water and dust from entering the ball joint and effectively prevent the grease from flowing out from the ball joint. .

  Further, the bearing seal 93 is less likely to be worn and damaged, unlike the dust strip 71 that slides tightly with the knuckle 5, so that a good sealing performance can be maintained over a long period of time.

  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 Bearing 71 Dustrip 72 Reinforcement ring 91 Inner race 92 Outer race 93 Bearing seal

Claims (4)

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 ball joint dust cover (6) has one large-diameter opening (8) fixedly held on the outer peripheral surface of the socket (3) and the other small-diameter opening (7) held on the shaft (4) side. In
A bearing (9) is fixedly held in the other end small diameter opening (7), and an inner race (91) of the bearing (9) is fitted and fixed on the outer peripheral surface of the shaft (4). A ball joint dust cover, wherein the outer race (92) of (9) is integrated with the other end small-diameter opening (7).   The dust cover for a ball joint according to claim 1, wherein a dust lip (71) in sealing contact with the knuckle (5) is formed in the other end small-diameter opening (7).   The outer race (92) of the bearing (9) is fitted and fixed to a reinforcing ring (72) made of a hard material integrally formed with the other end small-diameter opening (7). The dust cover for ball joints according to 1 or 2.   The dust cover for a ball joint according to any one of claims 1 to 3, wherein a bearing seal (93) is attached to the bearing (9).

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