JPS60143221A - Bearing for ball joint - Google Patents

Abstract

PURPOSE:To enlarge pressure receiving area in the drawing direction by providing a large opening at a spherical concave portion to facilitate insertion of a ball portion and forming a taper outer wall to serve as a suitable opening portion at the time of inserting the ball portion in a housing. CONSTITUTION:A spherical concave portion 12 of a bearing 10 of a ball joint used in a steering and suspension systems of a car comprises the first bearing surface 20 having a radius of R formed at the base thereof and the second bearing surfaces 21 having a radius of R from a center O' eccentric outward from the center O of the bearing surface. The eccentric center will enlarge an opening of the concave portion 12 to facilitate insertion of a ball, and a taper portion 30 is disposed on an outer wall 11. In this arrangement, at the time of inserting the ball in a housing, the taper portion 30 is pressed inward and deformed by the housing, thereby to reduce an opening of the spherical concave portion 12 and increase the area of the second bearing surface 21.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates primarily to improvements in ball joint bearings used in automobile steering or suspension systems.

Generally, this type of ball joint includes a U housing, a bearing made of an elastic material inserted into a recess in the housing, and a pole stud having a ball portion inserted into a spherical recess provided in the bearing. The ball part can be pushed into the spherical recess while expanding the opening of the spherical recess. In order to improve the surface resistance of such bearings, it is first required to increase the pressure-receiving area in the direction in which the bearing is pulled out, and secondly, it is required to increase the hardness of the bearing material. 1, the spherical recess 2 is shown in 5 as shown in FIG.
Because has a constant radius? In B, the opening diameter of this spherical recess 2 is set to be considerably smaller than the outer diameter of the ball part B of the ball stand 5.

Therefore, when trying to increase the pressure-receiving area, the opening diameter of the spherical recess of the bearing becomes smaller than the outer diameter of the ball part, and therefore the bearing may be destroyed when pushing the ball part into the spherical recess. [There was a drawback that it was 2 times long. For this reason, it has not been possible to satisfy the second requirement, which is to make the bearing soft and rough. Therefore, in conventional bearings, if an attempt was made to increase the pressure-receiving area and the hardness of the bearing, it would be difficult to design it, resulting in an increase in cost and disadvantages.

In addition, in the past, attempts have been made to create a bearing that is divided into two parts in order to overcome the following drawbacks, but such bearings have the following drawbacks.

(The cost was high because the number of 11 parts increased and the number of man-hours increased accordingly.

(2) Since it is divided into two parts, it is difficult to hold the ball part, and strict dimensional accuracy is required to hold it firmly.

(3) Grease leaks easily from the split points, which reduces durability.

An object of the present invention is to provide an integrally molded ball joint bearing that can be made of a material with high hardness and that can further increase the pressure receiving area in the drawing direction, thereby completely eliminating the drawbacks of the conventional bearings as described above. It's about doing.

Hereinafter, the present invention will be explained in detail based on the embodiments shown in FIGS. 2 to 5.

Referring to FIG. 2, a ball joint bearing according to the present invention is generally designated by the numeral 10 and has a generally cup-shaped shape having a circular outer wall 11 and a spherical recess 12. I'm annoyed. As shown in FIG. 6, the outer wall of this bearing is press-fitted into a concave hole 14 of the housing 1 and held therein, and the ball portion 16 of the trzH pole stud 15 is rotatably inserted into the spherical concave portion 12. Ru.

The spherical recess 12 consists of a first bearing surface 20 and a second bearing surface 21 . The first bearing surface consists of a spherical surface with diameter AtL 1 (, which forms the bottom of the spherical recess. The second bearing surface 21 is formed at the opening of the spherical recess. It consists of a spherical surface with a radius R centered at a point O' offset by e toward the opening of the spherical recess from the center O of the first bearing surface. Radius H of the second bearing surface.

are set the same and are approximately 12 mm, and the eccentricity e u:
It is smm. Of course, it is not limited to these values.

Since the center of the radius of the second bearing surface 210 is eccentric to the opening side of the spherical recess than the center of the first bearing 1M120, the opening diameter d of the spherical recess is set larger than the opening diameter of the four spherical parts of the conventional bearing. In the illustrated embodiment, the outer diameter of the ball portion is 24 mm, while the opening diameter d of the spherical recess is set to 22 mrn. Since the opening diameter d1 of the spherical recess is slightly smaller than the outer diameter of the ball, it is difficult to insert the ball into the spherical recess.

The outer wall 11&-1 of the bearing has a tapered portion 60 formed on the outer periphery of its spherical recess. This tapered portion 1 has an inclination that expands outward, that is, increases the outer diameter of the bearing. This slope is approximately 4° in the illustrated embodiment.

The outer diameter C at the base of the tapered portion 60 of the outer wall 11 is approximately the same as the inner diameter C' of the recessed hole 14 of the housing, but is set slightly larger. Therefore, when the bearing is press-fitted into the recessed hole of the housing, the opening of the spherical recessed part of the bearing is narrowed to d2 smaller than dl by the tapered part 30, and the second bearing surface 21 is applied to the outer peripheral surface of the ball part 16 with an appropriate pressure. Be pushed (see Figure 6).

As mentioned above, in the bearing of the present invention, in the free state, the opening diameter of the spherical recess is set slightly smaller than the outer diameter of the ball part to facilitate insertion of the ball part, and the ball part can be firmly held after assembly. ).

Referring to FIGS. 4 and 5, a variation of the bearing of the present invention is shown. In this variant d, the bearing has a plurality of oil sump recesses 40 formed in the spherical recess 12 and at least one slit 4 formed in the opening of the spherical recess.
1. When the ratio of the diameter of the opening of the bearing after press-fitting the bearing into the housing and the maximum diameter of the ball part is large, that is, the opening is tapered and opened [
When expanding one part, it can be provided if the press-fitting allowance between the bearing and the housing exceeds a certain limit value 7:.

According to the present invention, although the pressure receiving area is increased, when the upper ball portion is inserted into the spherical recess, it can smoothly pass through the opening of the spherical recess. There is a practical benefit of being able to do this.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of a conventional ball joint bearing showing a state in which the ball portion of a ball stud is being inserted, Fig. 2 is a cross-sectional view of a ball joint bearing according to the present invention, and Fig. 6 is a cross-sectional view of the ball joint bearing according to the present invention. FIG. 4 is a partial sectional view showing a state in which the bearing of the invention is assembled into a housing and the ball portion is inserted; FIG. 4 is a sectional view showing a modified example of the bearing of the invention;
FIG. 5 is a side view of FIG. 4. 10...Bearing 11...Outer wall 12...
- Spherical recess 16... Housing 14... Concave hole 15 - Ball stand 16... Ball part 20 - First bearing surface 21... Second bearing surface 30... Taper part 1st drawing, 3rd drawing, 4th drawing #, 5th drawing

Claims (1)

[Claims] In an integrally molded ball joint bearing, which is a spherical recess into which a ball portion of a ball stud is inserted into a recess provided in a housing, the spherical recess forms the bottom of the spherical recess. It consists of a hemispherical first bearing surface and a second bearing surface formed at the opening of the spherical recess, and the outer wall of the bearing at the opening of the spherical recess is formed into a tapered portion that expands outward. A ball joint bearing characterized by: