JPH10110738A - Boot - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of a gap between the thick section part of a boot and a mating member when the shape of the mating member to which the boot is attached is formed in a non-circular shape. SOLUTION: A groove 16 is axially formed in the thick section part 14 of a mounting part, mounted on the mating member, from an outer end face to form a belt-like part 17 continuous to a thin section part 15. This constitution extends only the thin section part 15 when the mounting part 12 is fixed at the mating member through a band 18, and prevents the generation of a gap between the mounting part and the mating member. Further, since the groove 16 is formed in the thick section part 14 to decrease thickness, the occurrence of shrinkage of the thick section part 14 during molding is reduced, a gap is prevented from being provided between the thick section part 14 and the mating member, and leakage of grease at the interior of a boot and penetration of water from the outside are prevented from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boot mounted on a device in which a shaft and a mating member move relative to each other, and more particularly to a boot in which the mating member has a non-circular shape.

[0002]

2. Description of the Related Art In automobiles and industrial machines, boots are mounted on joints where a shaft and a mating member move relative to each other to hold lubricating grease filled therein, and to prevent dust and water from entering from outside. And so on. The boot is generally formed of a rubber material or a resin material, and a bellows is formed between a portion fixed to the shaft and a portion fixed to the mating member so that the relative displacement between the shaft and the mating member can be absorbed. Has become. The shape of the mounting part of the boot is formed in a circular shape following the shaft and the mating member because the shaft and the mating member are usually formed in a circle, but in the tripod type joint, the mating member is formed in a non-circular shape, The shape of the boot mounting portion corresponding to that portion is also formed such that the inner peripheral surface is non-circular and the outer peripheral surface is circular.

FIG. 3 shows a longitudinal sectional view (a) and a transverse sectional view (b) of a boot used for a conventional tripod type joint. In FIG. 3, a boot has a first mounting portion 1 fixed to a shaft and a second mounting portion 2 fixed to a mating member.
And a bellows portion 3 connecting the mounting portions 1 and 2 on both sides. The mounting portions 1 and 2 are securely fixed to a shaft or a mating member by tightening the outer peripheral surface with a band. The first mounting portion 1 has a circular inner and outer peripheral surface along the axis, while the second mounting portion 2 has a circular outer peripheral surface and an inner peripheral surface of a joint outer ring as a mating member. In accordance with the outer peripheral shape, three thick portions 4 and three thin portions 5 connecting the three thick portions 4 on the circumference in a uniform direction have a continuous shape. In this way, by making the second mounting portion 2 non-circular in accordance with the shape of the mating member, the boot can be air-tightly mounted to the mating member, and leakage of internal grease and intrusion of water or the like from the outside can be achieved. Can be reliably prevented.

[0004]

However, the boot used in the conventional tripod type joint is a mating member as shown in FIG. 4 when the second mounting portion 2 is tightened to the mating member by a band. Recess 7 in joint 6
A gap 8 is formed between the gap 8 and the thick portion 4.
Grease may leak from the unit, or water may enter from the outside. It is considered that the gap 8 is generated because the thin portion 5 having a small thickness is excessively stretched when the band 8 is tightened with a band. Further, the gap 8 may not be generated at the corner of the recess 7 as described above, but may be generated at the center. this is,
It is considered that when molded using a resin material having a large shrinkage ratio, the thick portion 4 has a larger shrinkage, and a thinning occurs.

An object of the present invention is to solve such a conventional problem, and an object of the present invention is to provide a boot capable of securely sealing even if a mating member is non-circular.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a belt-shaped connecting portion for attaching a boot to a mating member by forming a groove in an axial direction from an outer end surface thereof and connecting the boot to a thin-walled portion. Since the thickness difference between the strip and the thin portion is small, only the thin portion does not extend when the mounting portion is fixed with the band, and shrinkage at the thick portion can be suppressed. Therefore, it is possible to prevent a gap from being formed between the member and the counterpart member.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A boot according to the present invention is a boot mounted on a device in which a shaft and a non-circular counterpart member move relative to each other, the first mounting having an inner and outer peripheral surface substantially similar to the shaft. Part, a second mounting portion having an inner peripheral surface and a circular outer peripheral surface substantially similar to the non-circular portion of the mating member, and a bellows portion connecting between the first and second mounting portions, A thick portion and a thin portion continuous in the circumferential direction are formed on the inner peripheral surface of the second mounting portion, and a groove is formed in the thick portion in the axial direction from the outer end surface to be continuous with the thin portion. Since the thin portion and the strip portion are continuous, the thickness of the strip portion is made closer to the thin portion, so that only the thin portion does not extend. Since no shrinkage occurs, it is possible to prevent the occurrence of a gap between the member and the mating member. Therefore, it is possible to prevent the grease inside the boot from leaking or water or the like from entering from outside. In particular, the present invention
It is suitable for application to non-circular mating members such as tripod joints, and when the boot is formed of a resin material, the shrinkage in the thick part is large, so it is also suitable for application to resin boots It is.

[0008]

FIG. 1 is a longitudinal sectional view (a) showing one embodiment of the present invention and a right end view (b) thereof. In FIG. 1, a resin boot includes a first mounting portion 11 fixed to a shaft,
It comprises a second mounting portion 12 fixed to the mating member and a bellows portion 13 connecting the both mounting portions 11 and 12. First
The mounting portion 11 has a circular shape on both the inner and outer peripheral surfaces along the axis, while the second mounting portion 12 has a circular outer peripheral surface, while the inner peripheral surface matches the outer peripheral shape of the mating member. Three thick portions 14 and three thin portions 15 connecting them in the same direction on the circumference have a continuous shape. And each thick part 1
4 has a V-shaped groove 16 formed in the axial direction from the outer end face along the inner peripheral surface protruding inward, and the V-shaped groove 16 forms a band-shaped portion 17 continuous with the thin portion 15. . The thickness t2 of the strip 17 is preferably equal to or greater than the thickness t1 of the thin portion 15.

Second mounting portion 1 for non-circular mating member
By making 2 into such a shape, the inner peripheral surface of the attaching portion 12 is constituted by the continuous thin portion 15 and the band-shaped portion 17, and the outer peripheral surface of the attaching portion 12 is fastened by the band 18. Occasionally, the elongation in the thin portion 15 and the strip portion 17 becomes substantially the same, and the occurrence of a gap due to a difference in thickness as in the related art can be prevented. In addition, since the thick portion 14 is thinned by the V-groove 16, even if a resin material having a large shrinkage rate is used, the band 17 does not lose its thickness, and the band 17 and the mating member are not thinned. Can be prevented from being generated between them.

In the above embodiment, the V-groove 1 is formed in the thick portion 14.
6, the belt-like portion 17 was formed.
As shown in (a), a straight groove 19 having a larger bottom portion may be used instead of the V groove. FIG. 2 (b)
By forming the groove 20 radially inward in the vicinity of the bottom of the V-shaped groove 16 of the thick part 14 as shown in FIG. This has the advantage of improving the adhesion to the mating member. Further, as shown in FIG. 2 (c), by forming the band mounting surface 21 of the thick portion 14 on an inclined surface facing inward in the axial direction, the V-groove 16 is crushed when the band 18 is tightened, so that the band mounting is performed. There is an advantage that the surface 21 is parallel to the axial direction and the tension force by the band 18 is equalized. others,
The shape of the thick portion 14 can be variously changed.

Although the above embodiment is an example in which the present invention is applied to a boot mounted on a tripod joint, the present invention is similarly applied to a boot used for another device having a non-circular mating member. can do.

Although the above embodiment is an example in which the present invention is applied to a resin boot, the boot may be formed using a rubber material.

[0013]

As described above, according to the boot of the present invention, the thick portion of the mounting portion to be attached to the mating member is provided with a groove in the axial direction from the outer end face to form a belt-like portion continuous with the thin portion. When the mounting portion is fixed to the mating member with a band, only the thin portion can be prevented from extending and a gap can be prevented from being formed between the thin portion and the mating member, and shrinkage during molding in the thick portion can be reduced. Thus, it is possible to prevent a gap from being generated between the thick portion and the mating member. Therefore, it is possible to prevent the grease inside the boot from leaking or water or the like from entering from outside.

[Brief description of the drawings]

FIG. 1A is a longitudinal sectional view of a boot showing an embodiment of the present invention, and FIG.

FIG. 2 is an enlarged partial cross-sectional view showing another configuration of the boot of the present invention (a), (b), and (c).

FIG. 3 is a longitudinal sectional view (a) and a transverse sectional view (b) of a conventional boot.

FIG. 4 is an enlarged partial cross-sectional view showing an example in which a gap is formed between the conventional boot and a mating member.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 1st mounting part 12 2nd mounting part 13 Bellows part 14 Thick part 15 Thin part 16 V groove 17 Band part 18 Band 19, 20 groove 21 Band mounting surface

Claims (3)

[Claims] 1. A boot mounted on a device in which a shaft and a non-circular mating member move relative to each other, a first mounting portion having inner and outer peripheral surfaces substantially similar to the shaft, and a non-circular shape of the mating member. A second mounting portion having an inner peripheral surface and a circular outer peripheral surface having a shape substantially similar to the portion, and a bellows portion connecting between the first and second mounting portions; A boot in which a thick portion and a thin portion continuous in the circumferential direction are formed on a surface, and a groove is formed in the thick portion in an axial direction from an outer end surface to form a band-shaped portion continuous with the thin portion. 2. The boot according to claim 1, which is mounted on a tripod joint. 3. The boot according to claim 1, wherein the material of the boot is resin.