JPH0749065Y2 - Ball joint - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The ball joint according to the present invention is used by being incorporated in a bearing portion or the like of a steering device or a suspension device for an automobile.

(Prior Art) A ball joint as shown in FIG. 2 is attached to a connecting portion of rods and arms which form a steering device, so that the rods and arms are swingably connected to each other. ing. This ball joint is configured by combining a joint pin 1, a housing 2, a sleeve 3, a pressing piece 4, a compression spring 5, and an end cap 6. At one end (the lower end in FIG. 2) of the joint pin 1, a sliding portion 7 having an outer spherical surface is formed, and the housing 2 supports the sliding portion 7 so as to be swingable. The support hole 8 is formed. A part of the inner peripheral surface of the support hole 8 is a spherical concave receiving surface 9, and a cylindrical fitting surface 10 is formed in the remaining portion, and a step is formed between the fitting surface 10 and the receiving surface 9. The part 11 is formed.

The sleeve 3 made of a slippery material such as oil-impregnated metal or nylon has an inner peripheral surface on the outer peripheral surface of the sliding portion 7, and an outer peripheral surface on the inner peripheral surface of the receiving surface 9. The outwardly facing flange-shaped parts 12 formed on the ends that are in close contact with each other.
Is engaged with the stepped portion 11 formed in the intermediate portion of the support hole 8, and is sandwiched between the outer peripheral surface of the sliding portion 7 and the inner peripheral surface of the support hole 8. The pressing piece 4, which is also made of a slippery material, is housed inside the fitting surface 10 and the inner surface (upper surface in FIG. 2) is the end surface (second surface) of the sliding portion 7.
(A lower surface in the figure). Further, the end cap 6 formed into a cylindrical shape with a bottom by pressing a stainless steel plate or the like is pushed into the inside of the fitting surface 10 with the opening facing inward (upper side in FIG. 2). Has been. Then, between the end edge 13 of the end cap 6 and the stepped portion 11, the outward flange-like portion provided at the end portion of the sleeve 3.
Holds twelve. Further, the compression spring 5 is provided between the end cap 6 and the pressing piece 4, and the elastic force of the compression spring 5 causes the inner surface of the pressing piece 4 to move toward the end surface of the sliding portion 7 of the joint pin 1. It is pressed elastically.

A caulking portion 14 is formed in a part of the housing 2 at a position surrounding the opening of the support hole 8. This caulking part
14 is formed by pushing the end cap 6 into the fitting surface 10 and then bending the end cap 6 inward in the diametrical direction (the left-right direction in FIG. 2). By pressing the caulked portion 14 against the inclined portion 15 of the end cap 6, the end cap 6 is prevented from coming out from the inside of the fitting surface 10.

In the ball joint configured as described above, the joint pin 1 and the housing 2 swing relative to each other within a range in which the sliding portion 7 formed at one end of the joint pin 1 can slide inside the sleeve 3. Or, it is allowed to rotate.

In FIG. 2, reference numeral 16 denotes a dustproof boot provided between the joint pin 1 and the housing 2, which allows dust and water to enter between the outer surface of the sliding portion 7 and the inner surface of the sleeve 3. Try to prevent.

(Problems to be Solved by the Invention) In the case of the conventional ball joint configured and operating as described above, the coupling strength of the end cap 6 to the housing 2 is not always sufficient. That is, in the case of the conventional structure, when the end cap 6 is connected to the housing 2, the caulking portion 14 provided on the housing 2 side is bent inward in the diametrical direction of the end cap 6, and the caulking portion 14 is formed. It is pressed against the inclined portion 15 of the end cap 6. Then, by this pressing, the end cap 6
Is prevented from slipping out from the inside of the fitting surface 10 and the grease enclosed in the housing 2 is prevented from leaking to the outside.

However, since the caulked portion 14 is pressed against the inclined portion 15, the force for pushing the end cap 6 into the inside of the support hole 8 is not necessarily large. For this reason, there is a possibility that the end cap 6 will loosen as it is used for a long period of time, and if it loosens, the grease filled in the housing 2 will come from the gap between the end cap 6 and the caulking portion 14. It may leak. The ball joint of the present invention eliminates such inconvenience.

(Means for Solving the Problems) The ball joint of the present invention, like the conventional ball joint described above, has a joint pin having a sliding portion whose outer surface forms a spherical convex surface at one end thereof, a housing, and this housing. A support hole having a part of the inner peripheral surface of which is a spherical concave receiving surface and the remaining part of which is a cylindrical fitting surface, and a step between the fitting surface and the receiving surface. An inner peripheral surface of the sliding portion is closely contacted with an outer peripheral surface of the sliding portion, and an outer peripheral surface thereof is closely contacted with an inner peripheral surface of the receiving surface. And a sleeve sandwiched between the outer peripheral surface of the sliding portion and the inner peripheral surface of the support hole in a state of being engaged with, and the inner surface of the sleeve is housed inside the fitting surface. The pressing piece that is brought into contact with the end face and the fitting surface that is formed in a cylindrical shape with a bottom and the opening portion faces inward And an end cap sandwiching the outward flange portion between the end edge and the step portion, and a compression spring provided between the end cap and the pressing piece.

Particularly, in the ball joint of the present invention, the outer peripheral edge portion of the end cap formed in the shape of a bottomed cylinder is formed by a convex curved surface whose cross section is an arc exceeding a quarter arc. ing. Further, a part of the housing is formed with a caulking portion projecting outward from the outer end surface of the end cap. Then, the end portion of the caulked portion is bent inward in the diametrical direction so that the cross-sectional shape exceeds a quarter arc, and the outer peripheral edge portion of the outer end portion is wrapped around the entire circumference, whereby the end cap is fitted. It is fixed inside the face-to-face.

(Operation) When the ball joint of the present invention configured as described above allows the joint pin and the housing to swing or rotate with respect to each other, the operation itself is the same as that of the conventional ball joint described above. It is similar to the case of.

Particularly, in the ball joint of the present invention, the caulking portion formed on a part of the housing has a stronger force to hold the end cap inside the fitting surface, which makes the end cap less likely to loosen and It is possible to effectively prevent the grease enclosed inside from leaking from the inside of this housing.

Also, in the case of the ball joint of the present invention, the outer peripheral edge of the outer end portion of the end cap is formed by a convex curved surface whose cross-sectional shape is an arc exceeding a quarter arc, and this outer portion is formed by a portion near the tip of the caulking portion. The outer peripheral edge of the end is wrapped all around. For this reason, a part of the inner peripheral surface of the caulked portion is not bent with an extremely small radius of curvature, and the caulked portion is not subjected to excessive stress, and the caulked portion is unlikely to be damaged.

Further, since the outer surface of the outer peripheral edge portion and the inner surface of the caulked portion are in close contact with each other over a wide area with curved surfaces, the sealability between the outer surface of the end cap and the inner surface of the caulked portion formed in the housing is improved. Is improved.

(Embodiment) FIG. 1 shows an embodiment of the ball joint of the present invention. The same parts as in the case of the conventional structure described above are designated by the same reference numerals to omit redundant description, and the characteristic parts of the present invention will be described below.

A caulking portion 17 is formed at a position surrounding a lower end opening of the support hole 8 in a part of the housing 2. This caulking part 17
Is made to project downward from the lower end surface of the end cap 18 formed in the shape of a short cylinder with a bottom. This end cap 18
The outer peripheral edge portion of the outer peripheral edge portion is formed with an annular projection 19 projecting outward (downward in FIG. 1), and the outer peripheral edge portion of the outer end portion has a cross section of a quarter arc. The convex curved surface exceeds.

Then, the end cap 18 is attached to the fitting surface of the support hole 8.
In fixing to the inside of 10, a part of the caulked portion 17 (a portion near the tip) is bent inward in the diametrical direction of the end cap 18 so that the cross-sectional shape exceeds a quarter arc. Then, the caulking portion 17 wraps the outer peripheral portion of the outer end portion around the entire circumference, and the end cap 18 is fixed to the inside of the fitting surface 10. In this manner, a part of the crimped portion 17 projects downward from the lower surface of the end cap 18 in a state where the crimped portion 17 is crimped and bent inward.

The operation itself of the ball joint of the present invention configured as described above when allowing the joint pin 1 and the housing 2 to rotate or swing relative to each other is as follows.
This is similar to the case of the conventional ball joint described above.
That is, the joint pin 1 and the housing 2 rotate or swing relative to each other within a range in which the sliding portion 7 formed at the end of the joint pin 1 can slide inside the sleeve 3. Allow things.

Particularly, in the joint pin of the present invention, a short cylindrical caulking portion 17 formed at a position surrounding a lower end opening of the support hole 8 in a part of the housing 2 fits the end cap 18 on a fitting surface.
The power to hold down inside 10 becomes stronger. The end cap 18 is securely prevented from loosening, and the housing 2
The grease enclosed inside effectively prevents the grease from leaking out from the inside of the housing 2 to improve the reliability of the ball joint,
Improves durability.

That is, in the case of the conventional structure, the caulking portion 14 (Fig. 2) suppresses the inclined portion 15 formed in a part of the end cap 6, so that only a part of the force generated by the caulking is applied to the end cap. Could not be used to suppress 6.
On the other hand, in the case of the structure of the present invention, the end cap 18 is formed by bending the crimped portion 17 beyond a quarter arc.
Since the end face of the end cap 6 is suppressed, all the force generated by the caulking can be used for suppressing the end cap 6. As a result, the force for holding the end cap 18 inside the fitting surface 10 becomes sufficiently large.

Further, in the case of the ball joint of the present invention, the outer peripheral portion of the outer end portion of the end cap 18 is formed by a convex curved surface whose cross-sectional shape exceeds a quarter arc, and the outer end portion of the caulking portion 17 is located near the tip end. The outer peripheral edge is wrapped around the entire circumference. Therefore, a part of the inner peripheral surface of the crimped portion 17 is not bent with an extremely small radius of curvature, and the crimped portion 17 is not bent.
Therefore, the caulking portion 17 is less likely to be damaged by cracks or the like without being applied with excessive stress.

Further, since the outer surface of the outer peripheral edge portion and the inner surface of the crimped portion 17 are in close contact with each other with curved surfaces over a wide area, the outer surface of the end cap 18 and the inner surface of the crimped portion 17 formed on the housing 2 are The sealability between them is improved.

Particularly in the case of the ball joint of the present invention, an annular projection 19 is formed on the peripheral edge of the end cap 18 so as to project outward (downward in FIG. 1), and the caulking portion 17 is formed inward. Since it is bent over a quarter arc so as to wrap this ridge 19 when it is bent, the supporting strength of the end cap 18 by this caulking portion 17 and the contact portion between the caulking portion 17 and the end cap 18 The sealing property of is sufficiently increased.

(Effect of the device) Since the ball joint of the present invention is constructed and operates as described above, the supporting strength of the end cap inside the supporting hole of the housing is sufficiently improved, and the reliability and durability of the ball joint are improved. Is improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the ball joint of the present invention, and FIG. 2 is a sectional view of a conventional ball joint. 1: joint pin, 2: housing, 3: sleeve, 4: pressing piece, 5: compression spring, 6: end cap, 7: sliding part, 8: support hole, 9: receiving surface, 10: mating surface, 11: stepped portion, 12: outward flange portion, 13: end edge, 14: crimped portion, 15: inclined portion, 16: dustproof boot, 17: crimped portion, 18: end cap, 19: ridge.

Claims (1)

[Scope of utility model registration request] 1. A joint pin having a sliding portion whose outer surface forms a spherical convex surface at one end thereof, a housing, and a part of an inner peripheral surface formed inside the housing, which serves as a spherical concave receiving surface. The remaining portion is a cylindrical fitting surface, and a supporting hole having a step between the fitting surface and the receiving surface, its inner peripheral surface is the outer peripheral surface of the sliding portion, and its outer peripheral surface is the above-mentioned outer peripheral surface. The outer peripheral surface of the sliding portion and the inner surface of the support hole are closely contacted with the inner peripheral surface of the receiving surface, and the outward flange portions formed at the ends are engaged with the step portion. A sleeve sandwiched between the peripheral surface, a pressing piece housed inside the fitting surface and having an inner surface abutting the end surface of the sliding portion, and a bottomed tubular shape,
An end cap that is pushed into the inside of the fitting surface with the opening facing inward, and that sandwiches the outward flange-shaped portion between the end edge and the step, and the end cap and the pressing piece. In a ball joint consisting of a compression spring provided between the end cap and the bottom end, the outer peripheral edge portion of the end cap formed in a cylindrical shape with a bottom is an arc whose cross-sectional shape exceeds a quarter arc. It is composed of a convex curved surface, and a part of the housing is formed with a caulking portion projecting outwardly from the outer end surface of the end cap. A ball joint characterized in that the end cap is fixed to the inside of the fitting surface by bending so as to exceed a quarter circular arc and wrapping the outer peripheral edge portion around the entire circumference.