JPH0317053Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) The present invention relates to a ball joint used in steering mechanisms, suspension mechanisms, etc. of automobiles.

(Prior art) Conventionally, in ball joints for automobiles, etc., which are small and can withstand high loads, after a ball stud head and a synthetic resin bearing member are assembled in the housing, the opening of the housing is It has been proposed that the ball stud be modified inward to surround the ball head of the ball stud.

(Problems to be solved by the invention) The above-mentioned type of ball joint can reduce the protruding opening of the shaft of the ball stud, so the load-bearing area can be increased, and the bearing member made of synthetic resin can also be used. Since it is deformed, there is an advantage that it is easy to wrap the ball head of the ball stud with the bearing member. However, since the housing and bearing members are deformed, they are susceptible to the cumulative tolerance of each component dimension, and it is very difficult to adjust the operating torque of the ball stud's swing and rotation during assembly. If this is not considered a problem, it is possible to easily cope with use under high load conditions, but it is necessary to stabilize the initial operating torque immediately after assembly or to maintain the initial operating torque from decreasing even during use. It was extremely difficult to sustain this.

The present invention was developed in view of these points, and it absorbs the cumulative tolerance of component dimensions and makes it easier to adjust the operating torque of the swing and rotation of the ball stud during assembly. The purpose is to stabilize the initial operating torque, absorb and alleviate various loads during use, and maintain the initial characteristics over a long period of time.

[Structure of the idea]

(Means for Solving the Problems) The ball joint of the present invention includes a housing 1 having openings 2 and 3 at both ends, a ball head 12 disposed inside the housing 1, and a ball joint 12 arranged in the housing 1. A ball stud 11 that integrally has a shaft portion 13 that continuously projects from an opening 2 at one end of a housing 1.
, a bearing seat 16 made of hard synthetic resin that is installed in the housing 1 and slidably encloses the ball head 12 of the ball stud 11; An annular spring member 26 made of elastic synthetic resin is installed between the ball head 12 of the ball stud 11 and the bearing seat 16, and a spring member 26 is fixed to the other end opening 3 of the housing 1 through the bearing seat 16. a plug 30 which applies a preload to the ball head 12 of the ball stud 11 by compressing the spring member 26; A plurality of band-shaped flat portions 23 are formed in the axial direction to form a straight line continuous with the outer curve without any step in the transverse direction, and a plurality of protrusions are formed on the inner periphery of the bearing seat 16 in a portion facing the spring member 26. 24 are formed radially so as to form a conical surface as a whole.

(Function) In the ball joint of the present invention, the plurality of band-like flat parts 23 are connected to the ball head 12 of the ball stud 11.
The plurality of protrusions 24 press against the spring member 26 and deform, thereby relieving the excessive pressure generated within the bearing seat 16 due to the cumulative tolerance of each component. The spring member 26 is compressed toward the center of the ball head 12 of the ball stud 11 to provide a pro-drade, and furthermore, prevents the spring member 26 from rotating together with the ball stud 11.

(Example) An example of the ball joint of the present invention will be described with reference to the drawings.

1 and 2 show a ball joint for low torque. In the figures, 1 is a metal housing, and this housing 1 has openings 2 at both ends,
3, one end of the inner chamber 4 on the opening 2 side is formed into a spherical shape, the other end on the opening 3 side is formed in a cylindrical shape, and the other end on the opening 3 side is formed in a cylindrical shape. As shown in FIG. 2, a substantially cylindrical caulking portion 5 is formed in the opening 3 via a step portion 6 before assembly and molding. In addition, this housing 1,
A mounting piece 8 having a mounting hole 7 is integrally formed on one side of the outer periphery, and an annular recess 9 is formed on the outer periphery of one end.

Further, reference numeral 11 denotes a metal ball stud, and this ball stud 11 has a ball head 12 disposed within the inner chamber 4 of the housing 1, and is connected to the ball head 12 of the housing 1. A shaft portion 13 protruding from the opening 2 at one end is integrally provided. Note that a threaded portion 14 is formed at the tip of the shaft portion 13 of this ball stud 11.

Further, 16 is a bearing sheet made of a load-bearing hard synthetic resin that exhibits good bearing properties, such as polyacetal resin, and as shown in FIGS. 3 and 4, this bearing sheet 16 is has a substantially cylindrical shape, and its inner surface includes a continuous large-diameter substantially cylindrical portion 17 whose diameter decreases slightly from one end to the other, a spherical dome portion 18, and a small-diameter cylindrical portion 19. At the inner peripheral end of the cylindrical portion 19, an annular shoulder portion 20 having a conical surface is formed.

On the inner surface of the bearing seat 16, in a cross section as shown in FIG. In the part shown by A in FIG. 4 extending from the ball stud 11 to the dome 18, that is, in the part directly facing the ball head 12 of the ball stud 11, a plurality of parallel threads are provided, each oriented in the axial direction, eight in this embodiment. In addition, eight trapezoidal projections 24 are provided radially on the shoulder portion 20 so as to form a conical surface as a whole. The outer diameter of the bearing seat 16 is larger than the inner diameter of the inner chamber 4 of the housing 1, and the height H of the band-shaped flat portion 23 is suitably 20 to 30 microns in this embodiment.

In addition, in FIGS. 1 and 2, 26 is a spring member made of elastic synthetic resin, and this spring member 26 is
It is annular and has a nearly triangular cross section,
It is located on the other end opening 3 side in the inner chamber 4 of the housing 1 and is inserted between the ball head 12 of the ball stud 11 and the bearing seat 16, and one side of the substantially triangular cross section is It comes into contact with the spherical head 12, and the other surface on the outer peripheral side comes into contact with the cylindrical portion 19 of the bearing seat 16 and the protrusion 24 of the shoulder portion 20.

A metal plug 30 is fitted onto the other substantially triangular surface of the spring member 26, that is, the surface on the other end opening 3 side of the housing 1. As shown in FIG. A flange-like edge 31 is hermetically crimped and fixed to the crimped portion 5 of the housing 1.

Further, as shown in FIG. 1, the housing 1
One end opening 2 is sealed by a boot 33 made of a flexible material such as rubber, and the shaft 13 of the ball stud 11 projects from the center of the boot 33. In addition, the installation of this boot 33 is as follows.
This is accomplished by fitting the edge 34 of the boot 33 into the annular recess 9 of the housing 1, and attaching a coil-shaped clip 35 made of a metal spring material to the outer periphery of the edge 34.

When assembling, as shown in the second line, the housing 1 is fixed on the jig 37, and the ball head 12 of the ball stud 11 is inserted into the inner chamber 4 of the housing 1. , insert the bearing seat 16 with the spring member 26 therein, further support the plug 30, press the plug 30 with the press device 38, and press the ball head 1 of the ball stud 11.
2 and bearing seat 16 into the inner chamber 4 of the housing 1, and the edge 3 of the plug 30.
1 is brought into contact with the stepped portion 6 of the housing 1, and in this state, the caulking portion 5 of the housing 1 is deformed inward over the entire circumference to caulk and secure the plug 30. Then, the housing 1 is removed from the jig 37. Remove and attach boots 33 and clips 35.

During this assembly, the substantially cylindrical portion 17 of the bearing seat 16 is deformed along the spherical shape of the opening 2 at one end of the inner chamber 4 of the housing 1 so as to enclose the spherical head 12 of the ball stud 11. There is.

In this assembled state, the band-shaped flat portion 23 of the bearing seat 16 is attached to the ball stud 1.
The bearing seat 16 deforms under pressure between the ball head 12 of the ball stud 1 and the housing 1, and relieves the excessive pressure generated within the bearing seat 16 due to the cumulative tolerance of each component.
To stabilize the initial operating torque of No. 1 and maintain this for a long period of time.

Furthermore, in this assembled state, a gap 21 is formed between the ball head 12 of the ball stud 11 and the bearing seat 16 as shown in FIG. 5, and an oil film is formed in this gap 21, which has a great effect on lubrication. shows.

Further, the plurality of protrusions 24 forming a conical surface of the bearing seat 16 are pressed by the plug 30 and compress the spring member 26 from the outer peripheral side toward the center of the ball head 12 of the ball stud 11. In addition to giving a stable preload, the spring member 26 is prevented from rotating together with the ball head 12 of the ball stud 11 during use, and the sliding resistance of the ball head 12 is stabilized.

Furthermore, the dome portion 18 of the bearing seat 16
is the first position of the ball stud 11 during use.
Since it faces the load in the direction of figure P and reduces the burden on the spring member 26, the spring force can be maintained over a long period of time.

Further, when producing the bearing seat 16, it is necessary that the band-shaped flat part 23 formed from the substantially cylindrical part 17 to the inner periphery of the dome part 18 is oriented in the axial direction and coincides with the separation direction of the mold. Since it forms a straight line that connects with the outer curve in the transverse direction without any steps, it has good mold release properties, does not complicate the mold structure, and can be easily molded. It is possible to finish with high precision, and the molding precision of the bearing seat 16 can be increased.
The operating torque of the ball joint becomes stable.

Next, FIGS. 6 and 7 show ball joints for high torque applications.

This ball joint for high torque has a compression spring 41 added to the ball joint for low torque described above, and the main structure and function are the same.

Therefore, this ball joint for high torque will only be described with respect to the differences, and the same parts will be described with the same reference numerals.

In this embodiment, a storage part 42 is formed in the center of the plug 30, and a metal coil-shaped compression spring 41 is stored in the storage part 42.
A metal annular spring sheet 43 is disposed between the compression spring 41 and the spring member 26, and by fixing the plug 30 to the housing 1, the compression spring 41
is in a compressed state, thereby increasing the operating torque of the ball stud 11.

In addition, the ball stud of this invention has an initial operating torque (initial friction torque) immediately after assembly of each individual product.
If the variation is about 10Kgcm (conventional general ball joints have a variation of more than 20Kgcm), and if the initial operating torque is about 35Kgcm, the decrease in operating torque (friction torque) due to use is 10Kgcm or less. We were able to confirm through experiments that this is true (compared to a conventional general ball stud with a drop of more than 25 kgcm).

Furthermore, in each of the above embodiments, the band-shaped flat portion 23
In addition to forming on the inner periphery of the bearing seat 16,
By forming a plurality of belt-shaped convex portions 51 (height h is 20 to 30 μm) as shown in FIG. 8 on the outer periphery of the bearing seat 16, it is possible to more easily absorb cumulative tolerances in the dimensions of each component. .

[Effect of idea]

As described above, according to the present invention, the belt-shaped flat part of the bearing seat that deforms when pressed against the ball head of the ball stud can absorb the cumulative tolerance of the dimensions of each component, so that the spring member can maintain an appropriate play load. can be obtained, and since the projection of the bearing seat compresses the spring member toward the center of the ball head, the preload by the spring member is stabilized,
As a result, the operating torque of the ball stud can be stabilized and variations between products can be reduced, and durability can be increased.Furthermore, since the spring member rotates together with the ball stud, the initial characteristics can be maintained. It can be sustained over a long period of time.

Furthermore, since a gap is formed between the ball head of the ball stud and the bearing seat, an oil film is formed in this gap, which has a great effect on lubrication. Furthermore, the belt-shaped flat part of the bearing seat is
It is oriented in the axial direction and coincides with the separation direction of the mold for molding the bearing seat, and in the transverse direction it forms a continuous straight line with no steps to the outer curve, so it has good mold release properties. The structure of the mold is not complicated, the mold can be finished with high precision, and the bearing seat can be molded with high precision, which stabilizes the operating torque of the ball joint.

[Brief explanation of the drawing]

Figures 1 to 5 show an embodiment of the ball joint of the present invention, with Figure 1 being a partially sectional side view, Figure 2 being a longitudinal sectional view showing its assembled state, and Figure 3 4 is a plan view of the bearing seat, FIG. 4 is a sectional view taken along the line -' in FIG. 6 shows another embodiment, FIG. 6 is a partially sectional side view, and FIG.
The figure is a longitudinal sectional view showing its assembled state, and
FIG. 8 is an enlarged plan view of a bearing seat showing a modified example. DESCRIPTION OF SYMBOLS 1...Housing, 2...One end opening, 3...Other end opening, 11...Ball stud, 12...Ball head 13
...Shaft part, 16...Bearing seat, 21...Gap part, 23...Band-shaped flat part, 24...Protrusion, 26...Spring member, 30...Plug.

Claims (1)

[Claims for Utility Model Registration] Integrally includes a housing having openings at both ends, a spherical head disposed within the housing, and a shaft protruding from the opening at one end of the housing in continuation with the spherical head. a ball stud; a hard synthetic resin bearing seat installed in the housing and slidably enclosing the ball head of the ball stud; An annular spring member made of elastic synthetic resin is installed between the head and the bearing seat, and the spring member is compressed through the bearing seat, which is fixed to the other end opening of the housing, and the ball stud is compressed. and a plug that applies a preload to the ball head of the ball stud, and a plurality of straight lines that are connected in a transverse direction to the outer curve without a step on a portion of the inner periphery of the bearing seat that directly opposes the ball head of the ball stud. A ball joint characterized in that a band-like flat part of the strip is formed in the axial direction, and a plurality of protrusions are formed radially on the inner circumference of the bearing seat in a portion facing the spring member so as to form a conical surface as a whole. Into.