JPH0942269A - Ball joint - Google Patents

Abstract

(57) [Abstract] [Problem] To secure lubricity by grease. SOLUTION: Fins 3 are provided on the inner peripheral surface of a dust cover 16.
0 is provided. A retainer 18 having fins 34 is attached to the shaft portion 14A of the ball stud 14. Therefore, the grease can be circulated and moved in the axial direction of the ball stud 14. Therefore, the lubricity of the sliding surface between the ball portion 14B and the seat 20 with the grease can be ensured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball joint including a socket, a ball stud and a dust cover.

[0002]

2. Description of the Related Art As an example of the structure of a conventional ball joint, there is a structure disclosed in Japanese Utility Model Laid-Open No. 5-196883. As shown in FIG. 6, the ball joint is provided with a cylindrical socket 100, in which the ball portion 102 of the ball stud 102 is provided.
A is arranged. A ball seal 104 made of an elastic material is interposed between the outer peripheral surface of the spherical portion 102A and the inner peripheral surface of the socket 100.

The shaft portion 10 of the ball stud 102 described above.
A knuckle arm 106 is connected to 2B, and a dust cover 108 for preventing dust and the like from entering is disposed between the knuckle arm 106 and the socket 100.
The dust cover 108 is made of an elastic material, and has a cylindrical main body 110, a seal lip 112 provided at one end of the main body 110, and a mounting portion provided at the other end of the main body 110. 114 are included. A reinforcing ring 116 is embedded in the seal lip portion 112 and is arranged in contact with the lower end surface of the knuckle arm 106. Further, the mounting portion 114 is arranged on the step portion 118 formed on the socket 100 and is fixed by the reinforcing ring 120.

Further, in this structure, a plurality of annular projections 122, 124, 126 are integrally formed on the inner peripheral surface of the main body 110. Each of the protrusions 122, 124, 126 extends toward the ball stud 102 side, and comes into contact with the shaft portion 102B of the ball stud 102 and the upper end portion of the socket 100 regardless of the swing of the ball stud 102. There is. Thereby, the above-mentioned seal lip portion 1
12 is prevented from falling toward the ball portion 102A.

[0005]

However, in the case of the configuration disclosed in the above publication, the annular protrusions 122, 1
Since 24 and 126 are in contact with the shaft portion 102B and the upper end portion of the socket 100, the substantial holding volume of the grease enclosed in the dust cover 108 is reduced. That is, the interior of the dust cover 108 is divided into a plurality of chambers by providing the plurality of annular protrusions 122, 124, 126, but is communicated with the sliding surface of the ball portion 102A and the ball seal 104. The chamber is only the chamber partitioned by the protrusion 122 and the protrusion 124. Therefore, the substantial holding volume of grease that can be supplied to the sliding surface is reduced.
Therefore, the amount of grease supplied to the sliding surface may be insufficient. That is, there is a problem that it is difficult to secure lubricity with grease.

In view of the above facts, the present invention has an object to obtain a ball joint capable of ensuring lubricity by grease.

[0007]

According to the present invention, a socket provided in a first connecting member, a sphere accommodated in the socket so as to be rotatable or swingable, and a second portion extended from the sphere. And a dust cover that covers a portion of the ball stud between the socket and the second connecting member and that has a lubricating oil inside thereof. And a fin protruding radially is provided on at least one of the inner peripheral surface of the dust cover and the outer peripheral surface of the shaft portion of the ball stud.

According to the above construction, since the fin protruding in the radial direction is provided on at least one of the inner peripheral surface of the dust cover and the outer peripheral surface of the shaft portion of the ball stud, when the dust cover and the ball stud rotate relative to each other, Lubricating oil inside the dust cover is circulated and moves in the axial direction of the ball stud.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION

[First Embodiment] A first embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, the ball joint 10 mainly includes a socket 12, a ball stud 14, and a ball stud 14.
It is composed of a dust cover 16 and a retainer 18. Hereinafter, description will be made in this order.

The socket 12 has a substantially cylindrical shape and is attached to the lower end of a wheel support (axle carrier) (not shown) as a first connecting member for supporting the wheel.
A thin sheet 20 made of an elastic material is attached to the inner peripheral surface of the socket 12.

The ball stud 14 has a tip portion (lower end portion).
A shaft portion 14A having a female screw formed on its peripheral surface, and the shaft portion 14A.
A spherical portion 14 integrally formed at one end (upper end) of A
B and. Of these, the ball portion 14B
Is rotatably accommodated in the seat 20 described above.
Further, the outer end portion 22A of the lower arm 22 of the front suspension is inserted into the shaft portion 14A, and in this state, the nut 24 is screwed and fixed.

A dust cover 16 is provided between the lower end of the socket 12 and the outer end 22A of the lower arm 22 described above. The dust cover 16 is made of an elastic material (resin,
It is made of rubber) and has a cylindrical shape before installation. One end portion (upper end portion) of the dust cover 16 is abutted and locked to a step portion 26 formed at the lower end portion of the socket 12, and a ring 28 is fitted and fixed in this state. Further, the other end (lower end) of the dust cover 16 is brought into contact with and locked to the outer end 22A of the lower arm 22.
Grease, which is lubricating oil, is enclosed in the dust cover 16. Further, a plurality of fins 30 are formed on the inner peripheral surface of the dust cover 16 in a radial direction at predetermined intervals (see FIG. 2).

On the axial center side of the dust cover 16, FIG.
The retainer 18 shown in (A) and (B) is arranged. The retainer 18 is made of an elastic material (resin, rubber),
Mounting portion 3 mounted on the shaft portion 14A of the ball stud 14.
2 and the fins 34 formed in the radial direction from the outer peripheral surface of the mounting portion 32 at a predetermined interval. The fins 34 are formed in a curved shape in the circumferential direction of the retainer 18 (see FIG. 3A). Also,
When the retainer 18 and the dust cover 16 are attached, the fins 34 of the retainer 18 and the fins 3 of the dust cover 16 are attached.
0 is in a non-contact state.

Next, the operation and effect of this embodiment will be described. When the relative rotation occurs between the wheel support and the lower arm 22, the relative rotation also occurs between the dust cover 16 and the ball stud 14. Therefore, the grease enclosed in the dust cover 16 circulates around the axis of the ball stud 14 by the fins 34 of the retainer 18 and the fins 30 of the dust cover 16. As a result, part of the circulated grease moves in the axial direction (upward) of the ball stud 14 and is supplied to the sliding surface between the ball portion 14B and the seat 20. As a result, the deteriorated grease and the non-deteriorated grease are replaced.

As described above, according to this embodiment, the retainer 1 is provided with the fins 30 on the inner peripheral surface of the dust cover 16 and the fins 34 on the shaft portion 14A of the ball stud 14.
Since No. 8 is attached, it is possible to ensure the lubricity of the sliding surface between the ball portion 14B and the seat 20 with grease. In particular, in the ball joint 10 (inverted ball joint) in which the dust cover 16 is arranged below the spherical portion 14B of the ball stud 14 as in this embodiment, the grease in the conventional dust cover 16 is almost wasted. However, according to this embodiment, the grease can be effectively used even for the inverted ball joint 10.

Further, conventionally, when an ice accretion phenomenon occurs in which ice adheres to the outer end portion 22A of the lower arm 22, etc., the dust cover 16 is pressed against the ball stud 14 side by the ice, and stress concentration on the dust cover 16 occurs. According to the present embodiment, the fins 30 are provided on the inner peripheral surface of the dust cover 16 to increase the rigidity thereof, so that such a problem does not occur.

Further, according to this embodiment, when the retainer 18 is attached to the ball stud 14, the fin 3
Since 4 is formed integrally with the cylindrical mounting portion 32, the mounting portion 32 only needs to be inserted into the shaft portion 14A of the ball stud 14, and the assembly is extremely easy. [Second Embodiment] A second embodiment of the present invention will be described below with reference to FIGS. 4 and 5.

The same components as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted.

As shown in these figures, in this embodiment, the shape of the fins 40 formed on the inner peripheral surface of the dust cover 16 and the fins 4 formed on the retainer 18 are used.
The shape of 2 is different from that of the first embodiment described above. More specifically, in the first embodiment described above, the fins 34 of the retainer 18 have a shape in which the cross-sectional area perpendicular to the axis increases as they go upward in the axis of the ball stud 14. In the above embodiment, the cross-sectional area of the fin 42 perpendicular to the axis is shaped so as to decrease toward the upper side of the axis of the ball stud 14. Correspondingly, the fin 40 of the dust cover 16 is also shaped such that its upper edge side projects toward the axis of the ball stud 14.

Also according to this embodiment, the above-mentioned first
The same operation and effect as those of the above embodiment can be obtained.

In the above embodiment, the ball joint 10 connecting the lower arm 22 and the wheel support.
The present invention is applied to the above, but the present invention is not limited to this, and any ball joint that connects members can be applied. For example, the present invention may be applied to an upper ball joint that connects the upper arm and the wheel support.

Further, in the above-described embodiment, the fins 30 and 34 (or the fins 40 and 42) are provided on the dust cover 16 and the retainer 18, but the present invention is not limited to this, and the fins may be provided on either one. Alternatively, the fins may be directly formed on the shaft portion 14A of the ball stud 14.

[0024]

As described above, in the ball joint according to the present invention, since the fin projecting in the radial direction is provided on at least one of the inner peripheral surface of the dust cover and the outer peripheral surface of the shaft portion of the ball stud, it is possible to use the grease. It has an excellent effect of ensuring lubricity.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a ball joint according to a first embodiment.

FIG. 2 is a horizontal sectional view of the dust cover shown in FIG.

3A is a plan view of the retainer shown in FIG. 1, and FIG. 3B is a side view of the retainer.

FIG. 4 is a sectional view corresponding to FIG. 1, showing a ball joint according to a second embodiment.

FIG. 5 is a side view of the retainer shown in FIG.

FIG. 6 is a sectional view showing a ball joint according to a conventional example.

[Explanation of symbols]

 10 Ball Joint 12 Socket 14 Ball Stud 14A Shaft 14B Sphere 16 Dust Cover 22 Lower Arm (Second Connecting Member) 30 Fin 34 Fin 40 Fin 42 Fin

Claims (1)

[Claims] 1. A socket provided in a first connecting member, a sphere that is rotatably or swingably accommodated in the socket, and a shaft that extends from the sphere and supports a second connecting member. And a dust cover that covers the portion of the ball stud between the socket and the second connecting member and that has a lubricating oil inside, and is a ball joint. And, a fin projecting in a radial direction is provided on at least one of the inner peripheral surface of the dust cover and the outer peripheral surface of the shaft portion of the ball stud.