JPS62137408A - Dust cover for ball joint - Google Patents

Abstract

PURPOSE:To reduce frictional resistance and to retain high sealing ability by providing an angle lip and a trapezoidal lip on the inner peripheral surface of an opening portion fitted to a handle portion of a dust cover, and making the interference larger at the angle lip and smaller at the trapezoidal lip. CONSTITUTION:An upper small opening portion 19 of a dust cover 18 formed by an elastic material such as rubber or the like is fitted to a designated position of a ball stud handle portion 15. A ring reinforcement 23 is buried in the small opening portion 19, and an outer peripheral lip 29 is integral with the upper end outer periphery thereof, a trapezoidal lip 25 and an angle lip 27 being integral with the inner peripheral surface, with a valley portion 26 interposed therebetween. The angle lip 27 has the width of a contact surface contacting the handle portion 15 narrower, and the trapezoidal lip 25 has the width of a contact surface wider. The interference is made larger at the angle lip, and smaller at the trapezoidal lip. Thus, breakage of a seal due to deformation can be prevented by the trapezoidal lip 25 so that the retention of high sealing ability is compatible with low frictional resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dust cover for a pole joint used in industrial applications such as automobile suspension systems and steering systems.

As a dust cover for the conventional technology pole joint,
There is a dust cover lJ\\ opening adapted to the ball stud handle, as in No. 87661, in which two or more seal lips having a predetermined tightness relative to the handle are formed.

Problems to be Solved by the Invention Regarding this point, as the shaft diameter of the shaft becomes thicker in accordance with the required specifications, the frictional resistance of this tightening margin increases, so it is necessary to apply grease or the like or to reduce the overall tightening margin. By reducing the number of holes, smooth sliding between the handle and the small opening was achieved.

However, the application of grease has problems such as an increase in assembly man-hours and dust adhesion, and a reduction in the interference poses a risk of deterioration of sealing performance.

Means for Solving the Problem A dust cover adapted to the handle of a ball stud is provided with a chevron-shaped lip 27 on the inner circumferential surface of the small opening 19 on the socket side, projecting in the inner circumferential direction and having a substantially sharp point and a narrow contact surface width. , and a trapezoidal lip 25 having a substantially trapezoidal shape and a wide contact surface width is provided on the inner circumferential surface of the small opening 19 on the side opposite to the socket, protruding in the inner circumferential direction, and the chevron-shaped lip 27 has a large tightening allowance for the handle portion 15. The trapezoidal lip 25 is made smaller.

The dust sealing function of the small opening is divided into each seal lip. In other words, only the clamping margin of the chevron-shaped lip with a narrow contact surface width slides with the handle with high sliding resistance and maintains high sealing performance, while the clamping margin of the trapezoidal lip with a wide contact surface has low sliding resistance and slides against the handle. This prevents the seal from breaking due to deformation of the small opening.

Embodiments Hereinafter, the configuration of embodiments of the present invention will be explained with reference to the drawings.

FIG. 1 shows an embodiment of a pole joint 10 equipped with a dust cover 18 according to the present invention. In the figure, 11 is a socket having a bearing member 13 on its inner periphery.

A pole stud 14 has a handle 15 and a spherical head 16 at the tip of the handle, and the head is supported on the inner spherical surface of the bearing member 13.

The upper opening 17 of the socket 11 allows the handle 15 of the pole stud to protrude, and the space around the opening is shielded from the outside by a dust cover 18.

The dust cover 18 is integrally molded with an elastic material such as rubber, and has a small upper opening 19 that is fitted into a predetermined position of the pole stud handle 15 and a lower large opening 21 that surrounds the socket 11. It fits into the groove 12.

This dust cover 18 has a bell shape (not shown) in its free state, and there is a sufficient repulsive force between the upper and lower openings 19.21 when the dust cover is compressed in the axial direction. A relatively thick cylindrical body portion 20 is provided so as to be able to hold the body.

A reinforcing ring 23 is integrally embedded in the small opening 19 of the dust cover 18, and as shown in FIG. A circumferential knob 29 is provided, and a trapezoidal lip 25 and a chevron-shaped lip 27 are formed on the inner circumferential surface with the valley portion 26 in between.

Outer circumference knob 292 trapezoidal lip 25 and chevron lip 27
are each formed in an annular shape without a break, and the outer circumference knob 2
9 is deformed and faces the end surface 31 of the connecting member 30, and has a trapezoidal lip 25. The chevron lip 27 is fitted onto the stud handle 15 with a tightness. The chevron lip 27 comes into contact with the handle 15 in a substantially acute shape that protrudes in the inner peripheral direction toward the socket side of the inner peripheral surface of the small dust cover opening 19. The width of the inner circumferential end, that is, the width of the contact surface is narrow.

Note that the cross-sectional shape of the chevron-shaped lip 27 is not limited to a sawtooth shape, but may be a half-moon shape.

On the other hand, the trapezoidal lip 25 has a substantially trapezoidal contact surface that protrudes in the inner circumferential direction on the side opposite to the socket of the inner circumferential surface of the dust cover small opening 19 so as to prevent the small opening 19 from being deformed when the pole stud swings. It is formed wide.

Further, the tightening allowance for the handle 15 is large for the chevron-shaped lip 27 and small for the trapezoidal lip 25 so that the sliding resistance with the handle 15 is small.

In the embodiment, since the small opening 19 is adapted to the non-tapered portion of the handle 15 when the dust cover is attached, the inner diameter of the chevron-shaped lip 27 is formed to be sufficiently smaller than the inner diameter of the trapezoidal lip 25.

Further, the large opening 21 of the dust cover 18 has an inner circumferential side adapted to the circumferential groove of the socket 11, and a circlip 24 is attached to the corresponding outer circumferential side, so that the large opening 21
I have given up on socket 11.

Effects As described above, according to the present invention, only the tightening portion of the chevron-shaped lip with a narrow contact surface width is in sliding contact with the handle portion with high sliding resistance, maintaining high sealing performance, and the trapezoidal lip with a wide contact surface width is The clamping margin slides into contact with the handle with low sliding resistance to prevent seal breakage due to deformation of the small opening, which has the effect of both reducing frictional resistance of the clamping margin and maintaining sealing performance.

[Brief explanation of drawings]

FIG. 1 shows an embodiment of the present invention, and is a partially sectional plan view of a pole joint. FIG. 2 is an enlarged cross-sectional view of a main part shown in the direction of arrow A in FIG. 1 with the dust cover in a free state. (Explanation of symbols) 10...Pole joint. 11...
...That's it. 14...Pole stud. 15...-...
Handle. 18...Dust cover. 19...
Small opening. 21... Large opening. 25...Trapezoidal lip. 27... Yamagata lip.

Claims (1)

[Claims] In a dust cover made of an elastic material such as rubber, which is attached to the socket 11 that holds the head 16 at the tip of the handled ball stud 14 and the handle 15 of the ball stud 14 in a state in which the height in the axial direction is compressed, the handle is A chevron-shaped lip 27 is provided on the socket side of the inner circumferential surface of the small opening 19 of the dust cover, which is adapted to the inner circumferential surface of the small opening 19, and protrudes in the inner circumferential direction and has a substantially pointed shape and has a narrow contact surface width. A trapezoidal lip 25 having a substantially trapezoidal shape and a wide contact surface width is provided on the side opposite to the socket and protrudes in the inner circumferential direction, and the tightening allowance for the handle portion 15 is made large for the chevron lip 27 and small for the trapezoidal lip 25. Dust cover for pole joints.