JP2592221Y2 - Dust cover for ball joint - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a dust cover for a ball joint.

[0002]

2. Description of the Related Art As shown in FIG. 4, a ball stud 21 having a knuckle arm 22 and a socket 23 have conventionally been used.
, A grease (not shown) is sealed therein, a substantially lantern-shaped film portion 1 is provided, and one end (upper upper end in the drawing) of the film portion 1 is fitted to the outer periphery of the ball stud 21. A ball joint dust cover provided with an annular seal portion 2 is known. The film portion 1 is formed of a rubber-like elastic material, and thus has flexibility to freely deform according to the swing of the ball stud 21. Seal part 2 is ball stud 21
And presses against the outer peripheral surface with a predetermined interference to prevent grease leakage and dust intrusion. Further, a reinforcing ring 3 is buried in the seal portion 2, and an annular seal protrusion 4 that contacts the lower surface of the knuckle arm 22 is provided.

[0003]

The above prior art has the following problems. That is, as shown in FIG. 5, when the ball stud 21 swings greatly, the seal portion 2 is strongly pulled by the film portion 1 on a part of the circumference (right side of the ball stud 21 in FIG. 5) and 21 may be separated from the outer peripheral surface, so that a so-called opening may occur, and the sealing property may be deteriorated.

[0004]

SUMMARY OF THE INVENTION In view of the above points, the present invention has been devised in order to solve the above-mentioned problems in the prior art. A seal is fitted on the outer circumference of the ball stud .
When the ball stud swings,
The seal part is a part of the circumference,
A ball joint dust cover that is pulled in a direction away from the pad, wherein a concave portion is formed at a boundary between the film portion and the seal portion.
And a thin portion is provided corresponding to the concave portion.
The thin portion is formed by the elastic deformation of the film.
Provided is a dust cover for a ball joint, wherein the dust cover absorbs a tensile force of a portion .

[0005]

When a concave portion is provided at the boundary between the film portion and the seal portion, the dust cover becomes thin at the portion where the concave portion is provided , and when the ball stud swings greatly, the tensile force of the film portion is applied to the thin portion. The thin portion deforms to absorb the tensile force. Therefore, tension of the membrane
Force does not reach the seal, and the seal is ball stud.
It is possible to prevent the user from moving away.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. The dust cover for a ball joint is mounted between a ball stud 21 having a knuckle arm 22 and a socket 23, and grease is sealed therein. In addition, a substantially lantern-shaped film portion 1 is provided, and an annular seal portion 2 fitted to the outer periphery of the ball stud 21 is provided at one end of the film portion 1, and further has the following configuration. .

Namely, as shown in FIG. 1, a recess 5 is provided on the inner surface side of the boundary of the membrane portion 1 and the sealing section 2, the thin portion 6 is provided in the portion where the concave portion 5 is provided. Further, in another embodiment shown in FIG.
A concave portion 7 is provided on the outer surface side of the boundary, and a thin portion 8 is provided in a portion where the concave portion 7 is provided. The depth of the concave portions 5 and 7 is set to be approximately 30% of the film thickness, and is preferably 30% or less in view of the strength of the thin portions 6 and 8. The recesses 5 and 7 are 1.0 to 3.0 from the end (outer peripheral edge) of the reinforcing ring 3.
It is provided at a distance of about mm.

[0008] Thus, according to such a recess 5,7 dust cover provided with a, as shown in FIG. 3, the thin portion 6 and 8 the tension of the film unit 1 when the ball stud 21 is largely swung As a result, the thin portions 6 and 8 are deformed to absorb the tensile force, thereby preventing the seal portion 2 from being pulled away from the outer peripheral surface of the ball stud 21. it can. That is, the greater the distance from the outer peripheral surface of the ball stud 21 to the seal portion 2, the greater the tensile stress does not occur. Note that the concave portions 5 and 7 and the thin portions 6 and 8 do not necessarily need to be annular.

[0009]

[Effects of the Invention] The present invention has the following effects.

[0010] That is, the concave portion is set as a boundary of the membrane portion and the sealing portion
And a thin part is provided corresponding to this recess.
The thin part is pulled by the elastic part due to its elastic deformation.
The ball stud swings to absorb
When the seal is pulled by the membrane, the ball stud
Can be prevented from moving away from
As a result, it is possible to improve the sealing performance of the sealing portion.
it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a mounted state of a ball joint dust cover according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a mounted state of a dust cover for a ball joint according to another embodiment of the present invention.

FIG. 3 is a sectional view showing an operation state of the ball joint dust cover of FIG. 1;

FIG. 4 is a sectional view showing a mounted state of a ball joint dust cover according to a conventional example.

FIG. 5 is a sectional view showing an operation state of the ball joint dust cover.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Membrane part 2 Seal part 3 Reinforcement ring 4 Seal protrusion 5,7 Depression 6,8 Thin part 21 Ball stud 22 Knuckle arm 23 Socket

Claims (1)

(57) [Scope of request for utility model registration] 1. A ball stud (2) is connected to one end of a membrane (1).
A seal portion (2) fitted on the outer periphery of 1) is provided.
When the ball stud (21) swings,
The membrane part (1) covers the seal part (2) at a part of the circumference.
In the dust cover for a ball joint, which is pulled in a direction away from the ball stud (21) , a concave portion (5) is formed at a boundary between the film portion (1) and the seal portion (2 ).
(7) is provided and the recesses (5) and (7) are
The thin portion and response (6) (8) is provided, the thin
The portions (6) and (8) are deformed by the elastic deformation of the film portion (1).
A dust cover for a ball joint, wherein the dust cover absorbs a tensile force .