JPH0389016A - Ball joint - Google Patents

Abstract

PURPOSE:To preserve grease for a long period of time by forming a plural number of grooves in the diametrical direction extending their middle surfaces traversely in the radial direction, with their one ends reaching a housing open end surface and with the other ends reaching a flange side surface, along the whole periphery of the middle surface. CONSTITUTION:A housing open end surface 8 and a middle surface 11 with a corner pert crossing with a flange side surface 10 chamfered is formed on a flange part 9. A plural number of grooves 12 in the diametrical direction extending across in the radial direction, with their one side ends reaching the afore-mentioned end surface 8 and the other ends reaching the flange side surface 10 are formed over the whole periphery on the middle surface 11. When a ball stud 2 vibrates, the vibration opposite side in the diametrical direction of a ball joint 1 of a dust cover 21 is pulled. Then, the inner surface of a trunk part 25 of the dust cover 21 is adhered to the middle surface 11, a space is formed between the flange side surface 10 and the afore- mentioned trunk part 25 and grease 31 is filled in this space 32. This grease passes the afore-mentioned grooves 12 in the diametrical direction, returns to the trunk part space 30 of the dust cover 21 and is reserved inside the dust cover 21 without flowing outside.

Description

DETAILED DESCRIPTION OF THE INVENTION =Object of the Invention= [Industrial Application Field] The present invention relates to a ball joint used in, for example, an automobile suspension system and a steering system.

[Conventional technology]

A ball joint with a dust cover has a chamfered or rounded intermediate surface on the flange formed on the housing to prevent the inner surface of the dust cover from being damaged by the edges of the flange. Ints include Utility Model Application No. 61-133116, Utility Model Application No. 61-157753, and Utility Model Application No. 63-3061.
No. 8.

Utility Model No. 63-1.26612, Utility Model No. 62-1553
No. 8, Utility Model Publication No. 17858/1983, Japanese Patent Publication No. 63-883
No. 78, JP-A-63-140107, JP-A-63-2
97811 etc.

[Problem to be solved by the invention]

In the above-mentioned ball joint, as shown in an enlarged view in FIG. 5, as the ball stand swings, the side of the dust cover 121 opposite to the swing is pulled in the swing direction from the position indicated by the two-dot chain line. .

At this time, the grease 131 filled in the dust cover 121 is trapped in the flange outer peripheral space 132 formed between the flange side surface 110 of the flange portion 109 and the body portion 125 of the dust cover 121. This grease 131 moves to the groove bottom corners 133, 134 of the dust cover attachment a120 of the housing 106, and moves to the groove bottom corners 133, 134.
It accumulates at 134. Thereafter, as the ball stud oscillates repeatedly, the amount of grease 131 accumulated in the groove bottom corners 133 and 134 increases, and is eventually pushed out of the ball joint 1 as shown in FIG. Sometimes.

The object of the present invention is to solve the above problems and provide long-term
To provide a ball joint that can securely hold grease in a dust cover.

=Structure of the invention= [Means for solving the problem] A radial groove extending radially across the intermediate surface, one end reaching the 71 housing opening end surface and the other end reaching the flange side surface is provided around the entire circumference of the intermediate surface. Form multiple units over multiple locations.

[Examples and effects]

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a ball joint 1 according to a first embodiment of the invention. In the figure, numeral 2 is a ball stud consisting of a handle 3 and a ball head 4, and 5 is a bearing made of thermoplastic synthetic resin, which slidably supports the ball head 4. The housing 6 encloses the ball head 4 of the ball stud 2 and the bearing 5, and has an opening 7 through which the handle 3 of the ball stud 2 projects. Meanwhile, a circumferential flange portion 9 is formed on the outer edge of the lower. Furthermore, a circumferential dust cover mounting groove 20 is formed on the outer peripheral surface of the housing 6 adjacent to the flange portion 9 .

The dust cover 21 is made of an elastic material and is approximately bell-shaped with a small opening 22 at one end and a large opening 26 at the other end.
The body portion 2 is an intermediate portion between the small opening 22 and the large opening 26.
5 bulges in the outer diameter direction. The small opening 22 is closely attached to the handle of the ball stud 2, and the large opening 26 is
It is installed in the dust cover installation groove 20 of the housing 6 described above, and the housing 6 is attached by a circlip 40.
The tightening is fixed. A body space 30 within the dust cover 21 is filled with grease 31.

Next, the shape of the above-mentioned flange portion 9 of the housing 6 will be described in detail. As shown in FIG. 3, which is an enlarged view of part A in FIG.
and a circumferential chamfered portion 11 as an intermediate surface formed by chamfering the corner portion where these two surfaces intersect. As shown in FIG. 2, this chamfer 11 has a radial groove 1 that extends radially across the chamfer 11 and has one end reaching the housing opening end surface 8 and the other end reaching the flange side surface 10.
2 is formed in plurality over the entire circumference.

Next, the movement of the grease 31 when the ball stud 2 swings will be explained. As shown in FIG. 1, when the ball stud 2 swings, the opposite side of the dust cover 21 in the diametrical direction of the ball joint 1 is pulled.

Then, as shown in FIG. 3, the body 2 of the dust cover 21
5 inner surface is almost in close contact with the chamfered part 11 of the flange part 9, and a flange outer peripheral space 32 is formed between the flange side surface 10 and the body part 25 of the dust cover 21, and the body part space 30 is formed here.
Grease 31 that has moved from inside accumulates. ball stat 2
By repeating the rocking, the flange outer peripheral space 3
2 is filled with grease 31, the grease 31 moves into the above-mentioned radial groove 12 formed in the chamfered portion 11 and returns into the body space 30 through there. Therefore, the grease 31 does not move to the groove bottom corners 33, 34 of the dust cover mounting groove 20, and does not leak out of the ball joint 1.

In the first embodiment, the intermediate surface of the flange portion is chamfered, and only the radial groove is formed.
The intermediate surface may be rounded, or, as in the second embodiment described below, an axial groove 13a may be formed on the flange side surface, continuing from each radial groove.

FIG. 4 is an enlarged view of the same part as part A in FIG. 1 of a ball joint according to a second embodiment of the present invention. The structure of the ball joint according to the first embodiment is the same as that of the ball joint according to the first embodiment except that the intermediate surface is the rounded surface 11a and the axial groove is formed.
The same reference numerals as those in the figure with the addition of "a" are given, and the explanation will be omitted. A plurality of axial grooves 13a are formed on the flange side surface 10a over the entire circumference, each of which corresponds to the radial groove 12 of the rounded surface 11a.
It is continuous with a. Therefore, even when the flange outer circumferential space 32a is filled with grease 31a to the vicinity of the dust cover mounting m 2 Oa due to the swing of the ball stud, the grease 31a first easily enters the axial groove 13a, and then the radial groove 12a. Move to dust cover 2
Since the grease 31a returns to the body space 30a of the ball joint 1a, the grease 31a does not leak out of the ball joint, similar to the ball joint according to the first embodiment.

=Effects of the Invention= As described above, according to the present invention, a radial groove extending radially across the intermediate surface, one end reaching the housing opening end surface and the other end reaching the flange side surface, is formed all around the intermediate surface. By forming a plurality of ball studs across the flange, the swinging of the ball stud causes the grease filling the flange outer space to pass through the radial groove and return to the body space of the dust cover, thereby preventing the grease from moving to the dust cover mounting groove. Therefore, the grease can be reliably held within the ball joint for a long period of time without leaking out of the ball joint.

[Brief explanation of drawings]

1 is a partially sectional plan view of a ball joint according to a first embodiment of the present invention, FIG. 2 is a top view of the housing shown in FIG. 1, and FIG. 3 is an enlarged view of section A in FIG. FIG. 4 is a cross-sectional plan view of the same part as FIG. 3 of the ball joint according to the second embodiment of the present invention, and FIG. 5 is a cross-sectional plan view of the same part as FIG. 3 of the conventional ball joint. . (Explanation of symbols) 1...Ball joint. 2... Ball stat. 3...Handle. 4... Ball head. 5...Bearing. 6...Housing. 7...Opening. 8... Opening end surface. 9...Flange part. 10...Flange side. 11...Intermediate surface. 12...Radial groove. 20...Dust cover installation groove. 21...Dust cover

Claims (1)

[Claims] A ball stud 2 having a ball head 4 at the tip of the handle 3;
a bearing 5 that slidably holds the ball head 4; and a housing 6 that encloses the bearing 5 and the ball head 4 of the ball stud 2, and that allows the handle 3 of the ball stud 2 to protrude from an opening 7. and a roughly bell-shaped dust cover 21.
A circumferential flange portion 9 and a dust cover mounting groove 20 adjacent to the flange portion 9 are formed at the outer edge of the opening 7 of the housing 6, and the circumferential housing constitutes the outer surface of the flange portion 9. In a ball joint 1 in which a circumferential intermediate surface 11 is provided between an open end surface 8 and a circumferential flange side surface 10, the ball joint 1 extends radially across the intermediate surface 11 and has one end reaching the housing open end surface 8. A ball joint characterized in that a plurality of radial grooves 12 are formed over the entire circumference of the intermediate surface 11, the other end of which reaches the flange side surface 10.