JP2544744Y2 - Ball joint - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ball joint used for various linkage portions of an automobile, and more particularly to a ball joint using a synthetic resin housing.

[0002]

2. Description of the Related Art A ball joint using a synthetic resin housing has a structure in which an inner concave spherical portion excluding an opening of a housing serves as a bearing surface for fitting and seating a ball head of a ball stud. In general, the ball head is assembled by pushing the spherical head from the opening of the housing into the concave spherical surface on the inner surface.

[0003] Therefore, the diameter of the opening of the housing cannot be made excessively smaller than the diameter of the ball head, and as a result, there is a problem that the holding force against the load in the pulling direction of the ball stud becomes small.

In view of the above problems, a reinforcing ring for preventing the expansion of the opening by reinforcing the outer periphery of the opening of the housing after the spherical head is fitted into the concave spherical surface of the housing. Is disclosed in Japanese Patent Laid-Open Publication No.
Nos. 77417 and 63-119925.

[0005]

As an example of a ball joint using a conventional synthetic resin housing as described above, the one shown in FIG. 5 has an opening 111 at the top and an opening 111 at the inner surface. A concave spherical portion 112 of a synthetic resin housing 110 having a continuous concave spherical portion 112 and an annular step 114 formed on an outer peripheral surface of the opening 111.
The ball head 121 of the ball stud 120 is directly fitted and seated. The annular step portion 114 has a predetermined distance from the top, and circulates substantially parallel to the axis of the concave spherical portion 112 of the housing 110.
14a and an annular flat surface portion 114b on which the lower end surface of the reinforcing ring 130 is seated, and the metallic reinforcing ring 130 for preventing the opening 111 from expanding is provided on the annular step portion 11.
4.

The outer peripheral surface 114a of the annular step 114 and the inner peripheral surface 130a of the reinforcing ring 130 are connected to the concave spherical surface 1a.
12 is a vertical plane having almost no inclination with respect to the axis of FIG.
As shown in the above, the accuracy of the press-fitting tolerance in the diameter is strictly required for the fitting of the two. That is, when the interference α of the fitting portion is small, the holding force with respect to the load in the pull-out direction of the ball stud is small. Conversely, when the interference α of the fitting portion is large, the inner peripheral surface 130a of the reinforcing ring 130 and the housing There has been a problem that the outer peripheral surface 114a interferes and press-fitting to the specified position becomes impossible.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a ball joint using a synthetic resin housing, which has an increased holding force against a load in a pulling direction of a ball stud.

[0008]

In order to achieve the above-mentioned object, the present invention has the following configuration.

The outer peripheral surface of the annular step portion and the inner peripheral surface of the reinforcing ring have substantially the same tapered shape converging toward the opening of the housing.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 10 denotes a synthetic resin housing. The housing 10 has an opening 11 at the top and a concave spherical surface 12 continuous with the opening 11 on the inner surface. The synthetic resin forming the housing 10 is a synthetic resin having appropriate elasticity and rigidity and excellent in self-lubricating properties, and examples thereof include a polyacetal resin, a polyamide resin, and a thermoplastic polyester resin. . Reference numeral 13 denotes an annular concave groove formed on the outer peripheral surface including the top opening 11 of the housing 10, and the annular concave groove 13 is continuous with the annular step portion 14 including the annular outer peripheral surface 14a and the annular flat surface 14b. I have. The outer peripheral surface 14a has a tapered shape converging toward the opening 11 of the synthetic resin housing 10.

[0012] 20 is a ball stud, the ball stud 20 has a shaft portion 22 formed integrally with the ball head portion 21 and the ball head 21. The outer diameter of the ball head 21 is formed larger than the diameter of the opening 11 of the synthetic resin housing 10, and the ball stud 20 fits the ball head 21 through the top opening 11 of the housing 10 and inserts the ball stud 20 into the housing 10. Is mounted on the housing 10 with the shaft portion 22 protruding from the opening 11.

Reference numeral 30 denotes a metal reinforcing ring disposed on the annular step portion 14 of the housing 10, and has an inner peripheral surface 30a.
Has a tapered shape converging toward the opening 11 of the housing 10. The reinforcing ring 30 has an inner peripheral surface 30a fitted to the outer peripheral surface 14a of the annular step portion 14, and an end surface 30b abutted on the annular flat end surface 14b to be fitted and seated on the annular step portion 14. ing. The inner peripheral surface 30a of the reinforcing ring 30 and the annular step portion 14 fitted as described above.
Has an approximately the same taper angle.

When the reinforcing ring 30 is fitted and seated on the annular step portion 14, it is not necessary to press-fit it with a large interference. When the reinforcing ring 30 is pressed into the annular step portion 14 with a large interference, the interference affects the inner concave spherical portion 12 of the housing 10, and the concave spherical portion 1.
This is because a predetermined torque applied between the spherical head 2 and the spherical head 21 fitted and seated on the concave spherical portion 12 varies.

Numeral 40 denotes a dust cover made of a rubber elastic material. One end of the dust cover 40 is fitted and fixed to the outer peripheral surface of the shaft portion 22 of the ball stud 20, and the other end is an annular concave groove of the synthetic resin housing 10. 13.

Reference numeral 50 denotes a fastening clip for fastening the dust cover 40 in the annular groove 13. The fastening clip 50 is formed by tightly winding a spring steel wire having a flat cross section in a coil shape, and the outer diameter of the fastening clip 50 is formed larger than the inner diameter of the reinforcing ring 30. A spring force is applied to the fastening clip 50 radially inward. When the dust cover 40 mounted in the annular groove 13 of the housing 10 is fastened and fixed in the annular groove 13 by the fastening clip 50, the outer surface of the fastening clip 50 has an annular step portion 14.
The fastening clip 50 is disposed outside the inner peripheral surface 30a side of the reinforcing ring 30 fitted to the outer ring, in other words, the fastening clip 50 is disposed so as to cover the fitting portion between the reinforcing ring 30 and the annular step portion 14. I have. By adopting such an arrangement, the fastening clip 5
Reference numeral 0 serves as a stopper for preventing the reinforcing ring 30 fitted to the annular step portion 14 from coming off in the axial direction of the ball stud 20.

Therefore, the outer peripheral surface 14a of the annular step portion 14 having substantially the same tapered shape converging toward the opening 11 of the synthetic resin housing 10 and the inner peripheral surface 30a of the reinforcing ring 30 are fitted. When the reinforcing ring 30 is press-fitted into the opening 11 of the housing 10, the tapered inner peripheral surface 30 a of the reinforcing ring 30 does not substantially interfere with the outer peripheral surface 14 a of the opening 11 of the housing 10 and smoothly reaches a predetermined position. Can be press-fitted. Also, housing 1
The reinforcing ring 30 tapered into the annular step portion 14 on the outer peripheral surface of the opening 11 has a substantially improved radial strength, and the reinforcing ring 30 against the load in the pull-out direction acting on the ball stud 20. Acts as a large resistance, so that the ball stud 20 can be prevented from coming out of the housing 10.

According to the present invention, the shape and material of the reinforcing ring 30 are not limited to these embodiments, and other portions of the ball joint may have other configurations as appropriate.

[0019]

As described above, according to the present invention, the outer peripheral surface of the annular step portion having substantially the same tapered shape converging toward the opening of the synthetic resin housing and the inner peripheral surface of the reinforcing ring are fitted. With this configuration, when the reinforcing ring is press-fitted into the opening of the housing, the tapered inner peripheral surface of the reinforcing ring can be smoothly pressed into a predetermined position with almost no interference with the outer peripheral surface of the opening of the housing. In addition, the reinforcing ring tapered into the annular step on the outer peripheral surface of the opening of the housing greatly improves the strength in the radial direction, and at the same time, the reinforcing ring has a large resistance to the load in the drawing direction acting on the ball stud. Since it acts as a force, it is possible to prevent the ball stud from coming out of the housing. Therefore, in the ball joint using the synthetic resin housing, it is possible to obtain a ball joint having an increased holding force against the load in the pull-out direction of the ball stud.

[Brief description of the drawings]

FIG. 1 is a partial sectional plan view showing a ball joint according to an embodiment of the present invention.

FIG. 2 is an enlarged view of part A of FIG. 1 showing a state before press-fitting of a reinforcing ring.

FIG. 3 is an enlarged view of a portion A in FIG. 1;

FIG. 4 is an enlarged view of part A of FIG. 1 showing a state before press-fitting of a reinforcing ring in a conventional ball joint.

FIG. 5 is an enlarged view of part A of FIG. 1 and the same part in a conventional ball joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Synthetic resin housing 11 Opening 12 Concave spherical surface part 14 Annular step part 14a Outer peripheral surface 20 Ball stud 21 Ball head 22 Shaft part 30 Reinforcement ring 30a Inner peripheral surface

Claims (1)

(57) [Scope of request for utility model registration] 1. A synthetic resin housing (10) having an opening (11) at the top and a concave spherical portion (12) connected to the opening (11) on the inner surface thereof has the opening (11). An annular step (14) is formed on the outer peripheral surface of the housing (10), and the concave spherical portion (12) of the housing (10) has a spherical head (2).
1) and a shaft (2) formed integrally with the ball head (21).
2), the ball head (21) is fitted and seated on the ball head (21), and the shaft (22) is arranged to protrude from the opening (11). The annular step (14) has a metal reinforcing ring (30) for preventing the opening (11) from expanding.
The outer peripheral surface (14a) of the annular step (14) and the inner peripheral surface (30a) of the reinforcing ring (30) face the opening (11) of the housing (10). A ball joint having substantially the same tapered shape that converges.