JPH0519634U - Ball joint joint dust cover - Google Patents

Abstract

(57) [Summary] [Structure] In a ball joint comprising a synthetic resin socket 1, a ball stud 2 having a spherical portion 2a fitted and held therein, and a dust cover 3 made of rubber,
The large-diameter fitting portion 31 of the dust cover 3 is embedded with the press-fitting ring 4 made of synthetic resin, and the inner peripheral surface 41 of the press-fitting ring 4 is pressed against the fitting groove 12 of the socket 1 over the entire circumference. [Effect] With the conventional press-fitting ring made of steel, the socket may bend due to the repeated load in the XX direction of the socket, causing an excessive load on the press-fitting ring and causing fatigue damage. By being manufactured, the press-fitting ring is elastically deformed in the extending direction according to the flexure of the socket, and an excessive load is not applied to the press-fitting ring, so that there is no fear of fatigue damage.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a dust cover for a ball joint, which comprises a socket made of a synthetic resin integrally molded product and a ball stud having a spherical portion fitted and held in the inner cavity of the socket at one end thereof. ..

[0002]

[Prior Art]

 A ball joint using a resin-integrated socket is conventionally known as disclosed in, for example, Japanese Utility Model Laid-Open No. 63-91718.

In this conventional ball joint, the spherical portion of the ball stud is press-fitted into the inner cavity portion of the socket made of a synthetic resin integrally molded product, and the press-fitting ring made of steel is embedded therein to open the socket end. A rubber dust cover having a large diameter fitting portion fitted to the outer periphery and a small diameter fitting portion fitted to the ball stud shaft portion at both ends is attached, and the dust cover serves as a socket inner cavity portion. It has a sealing function to prevent dust and water from entering the sliding contact surface between the ball and the spherical part from the outside, and prevents the socket opening from expanding and deforming at the large-diameter fitting part. It is designed to fulfill the function of retaining the spherical portion against the load in the pulling direction.

[0004]

[Problems to be solved by the device]

 The dust cover in which the steel press-fit ring is embedded in the large-diameter fitting part as described above has good assembling to the socket, but the socket is not subject to repeated load in the direction orthogonal to the axial direction of the ball stud. When actuated, the press-fitting ring made of steel does not expand or contract while the amount of deflection of the socket itself is relatively large, so the load input to the press-fitting ring becomes excessive and the press-fitting ring may be damaged by fatigue. have.

The present invention mainly aims to address the above-mentioned conventional problems.

[0006]

[Means for Solving the Problems]

 The present invention is characterized in that, in the ball joint using the synthetic resin socket as described above, the press-fit ring embedded in the large diameter fitting portion of the dust cover is made of synthetic resin instead of the conventional steel. To do.

[0007]

[Action]

 Due to the above, when a repeated load is applied to the socket in the direction orthogonal to the axial direction of the ball stud, the press-fitting ring made of synthetic resin also elastically deforms in the extension direction according to the deflection of the socket itself, which causes an excessive load on the press-fitting ring. There is no risk of fatigue damage to the press-fit ring without applying pressure. Also, even if the margin of the fitting groove on the outer circumference of the socket to which the dust cover is fitted is increased, the assembling property does not deteriorate, and it is possible to ensure both the assembling property of the dust cover and the removal strength. Moreover, since both the socket and the press-fitting ring are made of synthetic resin and have a linear expansion coefficient close to each other, it is possible to improve the sealing property against temperature change.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view showing an embodiment of the present invention, in which 1 is a resin socket integrally molded with a synthetic resin, and 2 is a spherical shape which is fitted in an inner cavity portion 1 a of the resin socket 1. The ball stud 3 having the portion 2a at one end is a dust cover made of rubber, and the large-diameter fitting portion 31 is fitted to the outer circumference of the opening end 11 of the resin socket 1, and the small-diameter fitting portion 32 is The ball stud 2 is fitted on the outer circumference of the shaft portion to seal the inside thereof from dust such as dust and water.

In the large-diameter fitting portion 31 of the dust cover 3, the press-fitting ring 4 integrally formed of synthetic resin is provided, and the inner peripheral surface 41 thereof is exposed at the entire inner peripheral surface of the large-diameter fitting portion 31. It is buried to do so.

On the outer peripheral surface of the socket 1 in the vicinity of the opening end portion 11, a fitting groove 12 having a substantially U-shaped cross section, into which the large-diameter fitting portion 31 of the dust cover 3 is fitted, is recessed over the entire circumference. The outer peripheral portion of the socket between the upper edge of the fitting groove 12 and the opening end portion 11 is formed into a tapered surface 13 of the tapered end so that the large-diameter fitting portion 31 can be easily pressed into the fitting groove 12. Is becoming.

The cross-sectional shape of the synthetic resin press-fitting ring 4 may be a rectangle close to a square as shown in FIG. 1, or may be below the inner peripheral surface 41 as shown in FIGS. 2 (A) and 2 (B). A structure may be adopted in which a tapered surface that expands toward the side is formed so that the socket 1 can be more easily press-fitted into the fitting groove 12 but is prevented from coming out.

By using the press-fitting ring 4 made of synthetic resin as described above, even a hard synthetic resin material is more likely to be elastically deformed in the extension direction as compared with a conventional steel-made material. Even if a repeated load is applied in the X-X direction and the socket 1 itself bends, the synthetic resin press-fit ring 4 does not have an excessive load due to its elastic deformation in the extension direction, and there is no risk of fatigue damage. Further, as described above, since it is elastically deformable in the extension direction, the assembling property does not deteriorate even if the engagement allowance of the fitting groove 12 is increased, and thereby the pull-out strength of the dust cover 3 is increased. Moreover, since the socket 1 and the press-fitting ring 4 that is press-fitted in the fitting groove 12 are both made of synthetic resin and have a linear expansion coefficient close to that of the steel, the ambient temperature is higher than that of steel. Good sealability against changes.

[0014]

[Effect of the device]

 As described above, according to the present invention, in the dust cover of the ball joint using the synthetic resin socket, the press-fit ring embedded in the large-diameter fitting portion of the dust cover is made of synthetic resin instead of the conventional steel. As a result, the conventional problem of fatigue damage to the press-fitting ring due to repeated load input to the socket can be solved, and the engagement allowance of the fitting groove provided on the outer periphery of the socket can be increased to improve the ease of assembly of the dust cover. It is possible to achieve both the securing and the improvement of the pull-out strength, and to improve the sealing property against the temperature change, which can bring about a great practical effect in combination with the cost reduction. ..

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

2 (A) and 2 (B) are cross-sectional views of essential parts showing another embodiment of the present invention.

[Explanation of symbols]

 1 Socket 2 Ball Stud 2a Spherical Part 3 Dust Cover 4 Synthetic Resin Press-Fit Ring 11 Open End 12 Fitting Groove 31 Large Diameter Fitting 32 Small Diameter Fitting

Claims (1)

[Scope of utility model registration request] 1. A socket made of a synthetic resin integrally molded product, a ball stud having a spherical portion at one end fitted and held in the inner cavity of the socket, an outer periphery of an open end of the socket, and a ball stud. In a ball joint consisting of a rubber dust cover having a large-diameter fitting portion and a small-diameter fitting portion that are respectively fitted to the outer circumference of the shaft portion, and sealing the sliding portion between the socket inner cavity portion and the spherical portion, A dust cover of a ball joint, wherein a large-diameter fitting portion of the dust cover is embedded with a press-fitting ring made of synthetic resin, the inner peripheral surface of which is pressed against the outer periphery of the opening end of the socket.