JP2012052614A - Dust cover for ball joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a dust cover for a ball joint which prevents deformation of a reinforcing ring upon plugging a large diameter opening into a socket, and which avoids the risk of interference between a membrane portion and the large diameter opening.SOLUTION: The dust cover for a ball joint made of a rubber-like elastic material has such a structure that a spherical head formed on one end of a ball stud is held in a socket; a shaft on the other end of the ball stud is fastened and fixed to a knuckle; one end of the cover having a large diameter opening where a metal reinforcing ring is embedded, is fixed and held on the outer circumferential face of the socket, the other end of the cover having a small diameter opening is held by the shaft, and the cover includes a drum-like membrane connecting the large diameter opening and the small diameter opening and bulging outward. The reinforcing ring is constituted of a base portion and a blade extending from the base portion to the outer circumferential face of the socket. The thickness in the axial direction of the base portion is larger than the thickness at the tip of the blade, and a joint width in the joining portion of the blade and the base is 1/2 or more of the thickness of the base in the axial direction.

Description

The present invention relates to a dust cover for a ball joint.
The present invention also relates to a ball joint dust cover used for an automobile suspension device, a steering device, and the like.

  Conventionally, as a ball joint to which a dust cover is attached for the purpose of dust-proofing and waterproofing of a ball joint joint portion, a dust cover for a ball joint shown in FIGS. 5 and 6 is known. (Patent Documents 1 and 2)

In this type of ball joint dust cover seal structure, a ball head 200 formed at one end of a ball stud 100 is held in a socket 300 as shown in FIGS.
The shaft 400 at the other end of the ball stud 100 is fastened and fixed to the knuckle 500.
On the other hand, one end large diameter opening 90 of the rubber-like elastic material dust cover is fixed and held by a metal reinforcing ring 600 embedded in the large diameter opening 90 on the outer peripheral surface of the socket 300, and the other end small diameter opening 70 is formed. The shaft portion 400 is configured to be held.
And the whole film | membrane part 800 which has connected the large diameter opening part 90 and the small diameter opening part 70 is exhibiting the drum shape which protruded outside.

The reinforcing ring 600 includes a base portion 610 and a blade portion 620 extending from the base portion 610 toward the outer peripheral surface of the socket 300.
The blade portion 620 bites into the outer peripheral surface of the socket 300 to prevent the dust cover from being detached from the socket 300.
For this reason, the blade portion 620 needs to have spring elasticity. On the other hand, the base portion 610 has sufficient rigidity so as not to be deformed when the large-diameter opening 90 is pushed into the socket 300 and the sealing performance is not deteriorated. It is necessary to have.

As shown in FIGS. 5 and 6, this kind of metallic material reinforcing ring 600 is manufactured by bending the outer peripheral side of an annular thin plate.
For this reason, the radial width A of the base 610 has inevitably increased.
As a result, as shown in FIGS. 5 and 6, the film portion 800 interferes with the large-diameter opening 90, and the film portion 800 is caused to wear out at an early stage.

In addition, if the radial width A of the base portion 610 is forcibly narrowed, the strength of the base portion 610 is reduced, causing a problem that the reinforcing ring 600 is deformed when the large-diameter opening 90 is pushed into the socket 300.
Further, since the joining width Z between the blade portion 620 and the base portion 610 cannot be greater than the plate thickness of the reinforcing ring 600, the joining strength between the blade portion 620 and the base portion 610 is insufficient, and the blade portion 620 There was also a problem that the fitting force was insufficient.

For this reason, a metal reinforcing ring 600 as shown in FIG. 7 has been proposed.
However, since the radial width A of the base 610 is extremely narrow in this type of reinforcing ring 600, when the large-diameter opening 90 is pushed into the socket 300, the large-diameter opening 90 becomes the end of the base 610 (the upper end in the figure). Caused damage.

JP 2009-24834 A JP 2001-323923 A

  The present invention has been made in view of such problems, and when the large-diameter opening is pushed into the socket, the reinforcing ring is not deformed, and there is no risk that the film part interferes with the large-diameter opening. An object is to provide a dust cover for a joint.

  In the dust cover for ball joint according to the present invention, a ball head formed at one end of the ball stud is held in the socket, and a shaft portion at the other end of the ball stud is fastened and fixed to a knuckle. One end large-diameter opening embedded therein is fixedly held on the outer peripheral surface of the socket, and the other end small-diameter opening is held by the shaft portion, and connects the large-diameter opening and the small-diameter opening. In a dust cover for a ball joint made of a rubber-like elastic material having a substantially drum-shaped film portion projecting outward, the reinforcing ring is composed of a base portion and a blade portion extending from the base portion toward the outer peripheral surface of the socket. And the axial thickness of the base portion is thicker than the thickness of the tip portion of the blade portion, and the joint width of the joint portion of the blade portion with the base portion is 1/2 or more of the axial thickness of the base portion. It is characterized by being.

The present invention has the following effects.
According to the dust cover for a ball joint according to the first aspect of the present invention, there is no risk that the film portion interferes with the large-diameter opening, and the base of the reinforcing ring has sufficient strength. When being pushed in, the reinforcing ring is not deformed and the large-diameter opening is not damaged by the reinforcing ring.

Furthermore, according to the dust cover for a ball joint of the invention described in claim 2, it is possible to reduce the risk that the film portion interferes with the large-diameter opening.
Furthermore, according to the dust cover for a ball joint of the invention described in claim 3, the reinforcing ring can be manufactured at a lower cost.

The longitudinal cross-sectional view of the dust cover for ball joints based on this invention. Sectional drawing of the reinforcement ring used for the dust cover for ball joints of FIG. The principal part enlarged view of FIG. The figure which showed the other example of the reinforcement ring used for this invention similarly to FIG. The longitudinal cross-sectional view of the dust cover for ball joints based on a prior art. The principal part enlarged view of FIG. The figure which showed the other example of the reinforcement ring used for the dust cover for ball joints of a prior art similarly to FIG.

Hereinafter, modes for carrying out the present invention will be described.
As shown in FIG. 1 to FIG. 3, the aspect of the dust cover for ball joint according to the present invention is as follows.
A ball head 2 formed at one end of the ball stud 1 is held in a socket 3, and a shaft portion 4 at the other end of the ball stud 1 is fastened and fixed to a knuckle 5, and a metal reinforcing ring 60 is embedded. One end of the large-diameter opening 6 is fixedly held on the outer peripheral surface of the socket 3, and the other end of the small-diameter opening 7 is held by the shaft portion 4, on the outside connecting the large-diameter opening 6 and the small-diameter opening 7. A substantially drum-shaped film portion 8 is provided.

The reinforcing ring 60 includes a base portion 61 and a blade portion 62 extending from the base portion 61 toward the outer peripheral surface of the socket 3, and the axial thickness X of the base portion 61 is the tip portion 621 of the blade portion 62. The joint width Z of the joint portion 622 with the base portion 61 of the blade portion 62 is designed to be ½ or more of the axial thickness X of the base portion 61.
Moreover, the groove part 624 side (upper side in the figure) of the joint part 622 with the base part 61 of the blade part 62 has an arc shape.

For this reason, the stress concentration of the joint part 622 with the base part 61 of the blade part 62 can be avoided, and the mechanical strength in the vicinity of the joint part 622 can be increased.
Thus, when the large-diameter opening 6 is pushed into the socket 3, the reinforcing ring 60 is not deformed, and the dust cover for the ball joint is free from the risk that the film portion 8 interferes with the large-diameter opening 6. I can do it.

Further, the blade portion 62 has a substantially truncated cone shape that is inclined toward the small-diameter opening 7 side (upward in the figure), and a plurality of notches provided at equal intervals on the tip portion 621 side. 623 is provided.
As a result, the large-diameter opening 6 forms a state in which it is more difficult to remove from the outer peripheral surface of the socket 3.

Further, the relationship between the radial length A of the base 61 of the reinforcing ring 60 and the radial length B of the blade 62 is designed to satisfy 1.0 <A / B <1.5.
By adopting such a shape, the base 61 of the reinforcing ring 60 can have sufficient strength. Therefore, when the large-diameter opening 6 is pushed into the socket 3, the reinforcing ring 60 is not deformed, and the ball joint Good sealing performance of the dust cover can be maintained.
In the case of 1.0 or less, when the large-diameter opening 6 is pushed into the socket 3, the area for receiving the pushing force of the reinforcing ring 60 is reduced, and it is interposed between the pushing jig (not shown) and the reinforcing ring 60. The risk of the rubber being damaged being damaged by the stress concentration is increased.
On the other hand, in the case of 1.5 or more, the risk that the film portion 8 interferes with the large-diameter opening 6 increases.

Further, the outer peripheral end 611 of the base 61 is chamfered with C0.5 or more or R0.5 or more.
By performing such chamfering, the risk that the film portion 8 interferes with the large-diameter opening 6 can be reduced.

Further, since the reinforcing ring 60 is formed by forging, the reinforcing ring 60 having a desired shape can be manufactured at a lower cost.
The dust cover is formed of various rubber-like elastic materials.

Next, another example of the reinforcing ring 60 used in the present invention will be described with reference to FIG.
The difference from the reinforcing ring 60 shown in FIG. 3 is that the axial thickness X of the base portion 61 is reduced, and the joining width Z of the joining portion 622 with the base portion 61 of the blade portion 62 is the axial thickness X. And the outer peripheral end 611 of the base 61 is subjected to larger chamfering.
For this reason, the axial direction thickness X of the base portion 61 is larger than the thickness Y of the tip end portion 621 of the blade portion 62, but is close to the thickness Y.

As a result, the reinforcing ring 60 can be made more compact, so that the risk of the membrane portion 8 interfering with the large-diameter opening 6 can be reduced.
Moreover, the groove part 624 side (upper side in the figure) of the joint part 622 with the base part 61 of the blade part 62 has an arc shape like the reinforcing ring 60 of the previous embodiment.

  Further, the present invention is not limited to the best mode for carrying out the invention described above, and various other configurations can be adopted without departing from the gist of the present invention.

  It can be used for ball joints used in automobile suspension systems and steering systems.

DESCRIPTION OF SYMBOLS 1 Ball stud 2 Ball head 3 Socket 4 Shaft part 5 Knuckle 6 Large diameter opening part 7 Small diameter opening part 8 Film | membrane part 60 Reinforcement ring 61 Base part 62 Blade part 611 Outer edge part 621 Tip part 622 Joint part 623 Notch part

Claims (3)

A ball head (2) formed at one end of the ball stud (1) is held in the socket (3),
The shaft (4) at the other end of the ball stud (1) is fastened and fixed to a knuckle (5), and a large-diameter opening (6) having a metal reinforcing ring (60) embedded therein is formed into the socket (3 ) Is fixedly held on the outer peripheral surface, the other end small diameter opening portion (7) is held by the shaft portion (4), and the large diameter opening portion (6) and the small diameter opening portion (7) are connected to each other. In the dust cover for a ball joint made of rubber-like elastic material provided with a substantially drum-shaped film portion (8) projecting outward, the reinforcing ring (60) is formed from the base portion (61) and the base portion (61). It is comprised from the blade part (62) extended toward the outer peripheral surface of a socket (3), and the axial direction thickness (X) of the said base part (61) is the thickness of the front-end | tip part (621) of the said blade part (62). It is thicker than (Y), and the joint width (622) of the joint part (622) with the base part (61) of the blade part (62) ( ) Is 1/2 or more of the axial thickness (X) of the base (61), and the radial length (A) of the base (61) and the radial length of the blade (62). The relationship with (B) is 1.0 <A / B <1.5, and the dust cover for a ball joint is characterized in that   The dust cover for a ball joint according to claim 1, wherein the outer peripheral end portion (611) of the base portion (61) is chamfered with C0.5 or more or R0.5 or more.   The dust cover for a ball joint according to claim 1 or 2, wherein the reinforcing ring (60) is formed by forging.

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