JPH10131942A - Ball joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball joint wherein generation of an internal chatter and damage of a ball seat can be prevented, in the case of applying a repeated load in an axial direction. SOLUTION: A ball joint has a ball stud 10 having a ball head part 11, socket 12 covering the ball head part 11, resin-made ball seat arranged in the inside of the socket 12, and a cap 13 fixed to the socket 12. The ball seat comprises an upper seat 2 and a lower seat 29. The upper seat 2 has a top surface part 201 facing the cap 13. The top surface part 201 holds a clearance always between a protrusion part 21 into contact with the cap 13 and the cap 13, but when a large compressive load is input in an axial direction of the ball stud 10, a contact part 22 into contact with the cap 13 and an elastic deflection part 23 are operated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball joint mainly used for an automobile suspension or the like.

[0003]

2. Description of the Related Art Conventionally, a ball joint provided on a suspension of an automobile has the following structure. That is, as shown in FIG. 4A, the ball joint 8 is a ball stud 10 having a ball head 11.
A socket 12 covering the ball head 11, a ball seat 80 disposed inside the socket 12 so as to face the ball head 11, and a ball seat 80 fixed to the opening 130 of the socket 12. And a cap 13 for holding the cap 80 with the ball head 11.

As shown in FIGS. 4A and 4B, in the ball seat 80, a top surface facing the cap 13 contacts the cap 13 at a central portion 81 and an outer edge portion 82 thereof. A space 83 is provided between the central portion 81 and the outer edge 82.

[0005] In the same figure, part C is the ball head 1
The ball core (center of the ball head) after assembly 1 and D are the lower surface of the cap 13 after caulking by the caulking portion 122, and E is the lower surface of the cap 13 before caulking. A dimension between the C portion and the D portion is A, and a dimension between the C portion and the E portion is B. That is, the value of BA is the interference of the ball seat 80.

In the ball joint 8, after the socket 12, the ball seat 80, the ball stud 11, and the cap 13 are provided, a caulking portion 122 is caulked with a roller or the like (not shown), and the tightening margin (B− A) Tighten the ball seat 80. Therefore, in the ball joint 8, the socket 12 is hardly generated in the socket 12, and has a high rigidity.

The lower end 89 of the ball seat 80
Has the shape shown by the dotted line in FIG. 4 (A) before the cap 13 is swaged,
Are narrowed down to the state shown by the solid line according to the shape of.

However, in the ball joint 8, the rigidity of the ball seat 80 is high, so that even if there is a slight variation in the size of the interference, the rotational torque suddenly increases or, conversely, the inside becomes loose. Or occur.

FIG. 5 shows another known ball joint having another structure. In this case, the ball seat in the ball joint 9 is
An upper sheet 90 disposed between the tip of the ball head 11 and the cap 13, a side end of the ball head 11 and the socket 1;
And a lower seat 99 disposed between the lower sheet 99 and the lower sheet 99. On the top surface of the upper sheet 90 facing the cap 13, a protruding projection 91 is provided.

In the ball joint 9, the projection 91 is slightly deformed by pressing, and the cap 13 is caulked and fixed to the socket 12 by the caulking portion 122.
Therefore, the protrusion 91 can absorb the backlash inside the socket 12.

The ball seat is an upper seat 9.
0 and a lower sheet 99, each of which has a shape corresponding to the shape of the ball head 11 with which it contacts. Therefore, in the ball joint 9 having the above-described structure, the dimensional variation can be absorbed, and the generation of the internal or excessive rotation torque caused by the variation can be suppressed.

[0012]

However, the ball joint 9 has the following problems. That is,
If the volume of the protrusion 91 is too large, the rotational torque may be excessive. On the other hand, if the volume is too small, when a compressive load is repeatedly applied in the axial direction of the ball stud 10, the projection 91 receives the entire compressive load and is deformed more than necessary. There is a possibility that an inner backlash may be generated between the first and the second. Also,
The inside play may damage the ball seat.

In view of the above problems, the present invention aims to provide a ball joint capable of preventing the occurrence of rattling and damage to a ball seat, particularly when a compressive load is repeatedly applied in the axial direction. Things.

[0014]

According to a first aspect of the present invention, there is provided a ball stud having a ball head, a socket for covering the ball head, and a resin-made resin disposed inside the socket so as to face the ball head. In a ball joint having a ball seat and a cap fixed to an opening of the socket and holding the ball seat between the ball head, the ball seat includes a tip of the ball head, a cap, And a lower seat disposed between the side end of the ball head and the socket, the upper sheet being in contact with the front end of the ball head. And a top surface facing the cap, and the top surface comprises:
A gap is always maintained between the projection that comes into contact with the cap and the cap inside the projection, but when a large compressive load is input in the axial direction of the ball stud, the contact that comes into contact with the cap is made. And a ball joint having an elastic bending portion between the protrusion and the contact portion.

The operation of the present invention will be described below. In the ball joint according to the present invention, on the top surface of the upper sheet, the projection that abuts the cap and the abutment that always keeps a gap between the cap and the inside of the projection are provided. It is provided. Further, an elastic bending portion is provided between the protrusion and the contact portion.

Therefore, when assembling the cap to the socket, the cap is crimped while pressing the projection and slightly deforming the projection. Thereby, the inside of the socket can be absorbed. In addition, a rotational torque can be obtained.

By setting the rigidity of the projection to be always higher than that of the elastic flexure, when a compressive load is applied in the axial direction of the ball stud, the elastic flexure is made of a disc spring. Acts as follows and absorbs compressive loads. For this reason, no excessive compressive load is applied to the protruding portion, and therefore, no deformation occurs.

Further, when a compression load larger than the above-mentioned state is input from the axial direction of the ball stud,
The elastic flexure further deflects, and accordingly, the contact portion is pushed in the direction of the cap, and finally the contact portion comes into contact with the cap to receive the axial compressive load.
Thereby, it is possible to prevent the elastic bending portion from being deformed more than necessary.

Further, in the ball joint according to the present invention, each part of the upper seat is deformed, so that each part can share and receive the compressive load in the axial direction. For this reason, it is possible to prevent the occurrence of backlash and prevent the ball seat from being damaged.

As described above, according to the present invention, it is possible to provide a ball joint capable of preventing the occurrence of rattling and damage to a ball seat, particularly when a compressive load is repeatedly applied in the axial direction. Can be.

The ball seat is made of resin and can be made of polyacetal resin, polyamide resin or the like.

The number of the protrusions is determined by the underbody structure of the vehicle, the weight of the vehicle, the direction and magnitude of the compressive load input from the road surface through the tire, and the material and protrusion of the resin used for the ball seat. Depending on the shape and volume of
Although each is determined, it is preferable that the number be 4 to 8 in consideration of securing the rigidity after assembly and stabilizing the rotational torque. The shape of the above-mentioned protruding portion is not limited to the shape in which the portion in contact with the cap is dotted,
For example, it may have various shapes such as an annular shape and an arc shape.

Further, the gap between the contact portion and the cap after assembly is the same as in the case of determining the number of the projections.
Various conditions must be considered. In particular, depending on the characteristics of the resin used, if the gap is too small, the contact portion may immediately hit the cap, and the rotational torque may increase. Conversely, if the gap is too large, the contact portion does not contact the cap even if an excessive compressive load is applied, and in the worst case, the upper sheet may be broken.

Next, as in the second aspect of the present invention, it is preferable that the back surface of the upper sheet has a concave portion on the opposite side of the contact portion so as not to contact the ball head. In other words, the recess can hold the lubricating oil such as grease, and the contact portion itself can have elasticity to help the elastic bending portion bend easily.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment A ball joint 1 according to an embodiment of the present invention will be described with reference to FIGS. The ball joint 1 according to the present invention is provided on a suspension of an automobile. For example, a socket 12 is connected to a vehicle body and a ball stud 10 is connected to a wheel.

As shown in FIGS. 1 to 3, the ball joint 1 of this embodiment comprises a ball stud 10 having a ball head 11.
A socket 12 that covers the ball head 11, a ball seat made of polyacetal resin disposed inside the socket 12 with the ball head 11 facing each other,
And a cap 13 that is fixed to the opening 130 and holds the ball seat between the ball head 11 and the ball seat 11.

As shown in FIGS. 1 to 3, the ball seat comprises an upper seat 2 disposed between a tip 111 of the ball head 11 and a cap 13, and a side end of the ball head 11. The lower seat 29 is provided between the portion 112 and the socket 12. The upper sheet 2 has a back surface 202 that contacts the tip 111 of the ball head 11 and a top surface 201 that faces the cap 13.

As shown in FIGS. 1 to 3, the top surface 201 is provided with a projection 21 abutting on the cap 13.
And the cap 1 inside the projection 21.
3 and a ball stud 1
And a contact portion 22 that comes into contact with the cap 13 when a large compressive load is input in the 0 axial direction. An elastic flexure 23 is provided between the protrusion 21 and the contact portion 22.

As shown in FIGS. 1B and 3, four protrusions 21 are provided at equal intervals in the circumferential direction. Also,
As shown in FIG.
The gap K between the cap and the cap 13 is 0.5 mm.
Further, as shown in FIG. 1A, the back surface 202 of the upper sheet 2 has a concave portion 24 on the opposite side of the contact portion 22 so as not to contact the ball head 11. The rigidity of the protrusion 21 is always higher than that of the elastic flexure 23.

Therefore, the cap 1 is attached to the socket 12.
When assembling the cap 3, the cap 13 is pressed and the cap 13 is swaged while slightly deforming the same.
And fix it by swaging. Thereby, the socket 12
Inside can absorb the inside. In addition, a rotational torque can be obtained.

Next, the operation and effect of this embodiment will be described. A state in which a compressive load is applied to the ball joint 1 of the present embodiment from the axial direction of the ball stud 10 will be described. In response to the compressive load, first, the elastic flexure 2
3 is deformed upward like a disc spring to absorb the compressive load. Then, the protrusions 21 are larger than the elastic bending portions 23.
Since the rigidity is higher, no deformation occurs in the projection 21 at this time.

When a compressive load larger than the axial direction of the ball stud 10 is applied from this state, the elastic bending portion 23 further bends, and accordingly, the contact portion 2
2 is pushed in the direction of the cap 13 and starts to deform.
On the opposite side of the contact portion 22, there is provided a recess 24 that does not contact the ball head 11.

When a compressive load is further applied than in the above state, the contact portion 22 comes into contact with the cap 13 and receives the compressive load there. When the contact portion 22 comes into contact with the cap 13, the elastic bending portion 23
Can be prevented from deforming beyond its own elastic limit.

Further, in the ball joint 1 of the present embodiment, each part of the upper seat 2 is deformed, so that the above-mentioned compressive load can be shared and received by each part. For this reason, it is possible to prevent the occurrence of backlash and to prevent the upper sheet 2 from being damaged.

Therefore, according to the present embodiment, it is possible to provide a ball joint which can prevent the occurrence of backlash and damage to the ball seat, especially when a compressive load is repeatedly applied in the axial direction.

[0036]

As described above, according to the present invention, there is provided a ball joint capable of preventing occurrence of rattling and damage to a ball seat, especially when a compressive load is repeatedly applied in the axial direction. be able to.

[Brief description of the drawings]

FIG. 1A is a cross-sectional explanatory view of a ball joint and FIG. 1B is a plan view of an upper sheet according to a first embodiment.

FIG. 2 is an explanatory sectional view of an upper sheet according to the first embodiment.

FIG. 3 is a perspective view of an upper sheet according to the first embodiment.

4A and 4B are explanatory views of a cross section of a ball joint and a plan view of a ball seat in a conventional example.

FIG. 5 (A) shows a conventional example of a ball joint having a ball seat composed of an upper seat and a lower seat.
Sectional explanatory view, (B) The top view of an upper sheet.

[Explanation of symbols]

 1,8,9. . . Ball joint, 10. . . Ball studs, 11. . . Ball head, 111. . . Tip, 112. . . Side edges, 12. . . Socket, 13. . . Cap, 130. . . Openings, 21, 91. . . Projection, 22. . . Contact part, 23. . . 23. elastic flexure, . . Recess, 2,90. . . Upper sheet, 29, 99. . . Lower sheet,

Claims (2)

[Claims] 1. A ball stud having a ball head, a socket covering the ball head, a resin ball seat disposed inside the socket so as to face the ball head, and an opening of the socket. A ball joint having a cap fixed to the portion and holding the ball seat between the ball head and the ball head, wherein the ball seat is provided between the tip of the ball head and the cap. A lower sheet disposed between the side end of the ball head and the socket; the upper sheet facing the tip of the ball head and facing the cap; A top surface portion, and the top surface portion always keeps a gap between the projection abutting on the cap and the cap inside the projection, but in the axial direction of the ball stud. Large compressed load A ball joint comprising: a contact portion that comes into contact with a cap when a weight is input; and a resilient flexure between the protrusion and the contact portion. 2. The ball joint according to claim 1, wherein the back surface of the upper sheet has a concave portion on the opposite side of the contact portion so as not to contact the ball head. [0001]