JPH0523853Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a dust cover for a ball joint.

BACKGROUND ART A ball joint generally includes a ball stud with a ball portion formed at one end of the shaft portion, a ball seat that fits and holds the ball portion of the ball stud, and a ball seat that fits and holds the ball portion of the ball stud.
a socket into which the ball seat is fitted;
Typically, the ball stud is allowed to swing within the opening of the socket.

Furthermore, in the case of a ball joint, a dust cover made of an elastic material such as rubber is attached by fitting one end onto the outer periphery of the socket and making elastic contact with the other end onto the shaft of the ball stud. The dust cover provides an airtight seal to prevent dust, water, etc. from entering the socket through the socket opening.

Problems to be Solved by the Invention Conventionally, for example, as shown in FIG. The small-diameter end D2 is comprised of a small-diameter end D2 that is fitted into the shaft of the ball stud C that is fitted and assembled so as to be swingable, and a bellows part D3 that is easily elastically deformed.
The ball stud C is attached to the lower side of the flange part C2, which is the mounting seat for other parts provided on the ball stud C.
It is assembled in a state where it is in elastic contact with the outer circumference of the shaft part over the entire circumference.

The bellows portion D3 must have a sufficient margin so that it can elastically deform to follow the rocking movement when the ball stud C swings about the center point of the ball portion C1. 4. When the ball stud C swings greatly from the neutral state shown in the figure in a certain direction, for example, to the left in the figure, the bellows part on the right side expands and the bellows part on the left side contracts, and the above-mentioned flange part C2 is attached to the contracted bellows part on the left side. This will cause contact interference.

In this case, the flange portion C2 is composed of a metal nut, so if the metal repeatedly contacts and interferes with the bellows portion of the dust cover made of an elastic material such as rubber, the bellows portion may be worn out or damaged. This poses a problem in that the durability of the dust cover is significantly reduced.

The present invention aims to address the conventional problems as described above.

Means for Solving the Problems The present invention provides a dust cover for a ball joint as described above, in which an elastic force is applied over the entire circumference to the outer peripheral surface of the flange portion which serves as a mounting seat for other parts of the ball stud at the small diameter end of the dust cover. It is characterized in that the contacting annular projections are integrally formed into branched projections.

As a result of the above, the vicinity of the lower corner of the flange located above the small diameter end of the dust cover that is in elastic contact with the shaft of the ball stud over the entire circumference is covered with an annular projection that is in elastic contact with the entire circumference. When the ball stud swings significantly and the flange comes into contact with and interferes with the bellows part of the dust cover,
The metal flange does not come into direct contact with the bellows, but instead comes into contact with the elastic material.
The risk of frictional damage to the bellows portion is greatly reduced.

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

In FIG. 1, 1 is a ball stud with a ball portion 11 formed at one end, and 2 is the ball stud 1.
A ball seat 3 that fits and holds the ball portion 11 of the
is a socket into which the ball seat 2 is fitted;
The ball seat 2 fitted with the ball portion 11 of the ball stud 1 is press-fitted into the socket 3, and the socket 3 is assembled by caulking the opening edge of the socket 3.

Reference numeral 4 denotes a dust cover made of an elastic material such as rubber, and the dust cover 4 has a large diameter end 41 that is fitted onto the outer circumferential surface of the socket 3 and fixed by means such as adhesive, and a shaft of the ball stud 1. The socket 3 is formed into a substantially cylindrical body having a small diameter end 42 which is fitted into the socket 3 and comes into elastic contact with the outer circumferential surface of the shaft, and a bellows part 43. It is sealed so that no one can get in and the lubricating grease inside cannot leak out.

The above ball joint generally has socket 3 fixed to one part and ball stud 1.
Since the shaft of the ball stud 1 is used by fitting it into the other part and fixing it by tightening a nut, etc., the shaft of the ball stud 1 is provided with a flange part 12 that serves as a mounting seat for the other part. The flange portion 1
2 is usually constituted by a nut-shaped member with a female threaded hole in the center as shown in the first figure so that it can be attached after the small diameter end 42 of the dust cover 4 is fitted into the shaft of the ball stud 1. Normally, the small-diameter end 42 of the dust cover 4 is assembled to the shaft portion of the ball stud 1 in a state where it contacts the lower surface of the flange portion 12 over its entire circumference.

In the present invention, at the root of the small diameter end 42 of the dust cover 4, that is, at the connection to the bellows part 43,
A substantially circular projection 44 is integrally formed to protrude and branch, and when the dust cover 4 is assembled, the circular projection 44 fits elastically into contact with the outer peripheral surface of the flange portion 12 over the entire circumference and contacts the lower surface of the flange portion 12. The structure is such that it completely covers the area from about the lower half of the outer circumferential surface.

The inner peripheral surface of the annular projection 44 may be provided with a lip portion 44a as shown in FIGS. 2 and 3, and as shown in FIG. The dust cover 4 has an annular protrusion 44 on the circumferential surface of the lower half.
It is also possible to have a structure in which the two elements fit into elastic contact.

The range in which the annular projection 44 fits and comes into elastic contact is approximately 1/2 to 1/3 of the height of the flange portion 12.

The structure of the large-diameter end 41 of the dust cover and the means for fitting it into the socket are not limited to the illustrated embodiment, and any configuration can be adopted, and the ball joint to which the dust cover of the present invention can be applied is also limited to that illustrated. It is applicable to ball joints of any structure.

Effects of the Invention According to the present invention configured as described above, the sealing function of the small diameter end portion 42 of the dust cover is further improved by the elastic fitting of the annular protrusion 44 to the lower part of the outer periphery of the flange portion 12. ball stud 1
When the flange portion 12 swings greatly and comes into contact and interference with the bellows portion 43 of the dust cover, the contact is not between metal and elastic material such as rubber, but between elastic material and elastic material, resulting in contact interference. Even if this is repeated, the risk of wear and tear on the bellows part is significantly reduced, and the durability of the dust cover can be greatly improved. Combined with the simple structure and almost no increase in cost, this has a great practical effect. It is possible to bring about

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional front view showing an embodiment of the present invention;
FIGS. 2 and 3 are sectional views of main parts showing other embodiments of the present invention, and FIG. 4 is a vertical sectional front view showing a conventional example. 1...Ball stud, 12...Flange part,
2... Ball seat, 3... Socket, 4... Dust cover, 41... Large diameter end, 42... Small diameter end, 43... Bellows portion, 44... Annular projection.

Claims (1)

[Scope of utility model registration request] A ball stud, a ball seat that fits and holds the ball portion of the ball stud, a socket that fits the ball seat, and a large diameter end that is fixed to the socket and a small diameter end that is fitted to the shaft of the ball stud. In a ball joint consisting of a dust cover made of an elastic material such as rubber that prevents dust from entering into the socket by making bullet-loading contact, the small diameter end of the dust cover is in elastic contact with the ball stud shaft over the entire circumference. A dust cover for a ball joint, characterized in that an annular protrusion is integrally formed on the outer peripheral surface of a flange portion, which serves as a seat for attaching other parts of the ball stud, and comes into elastic contact with the entire circumference.