JPH017854Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to a rubber boot used for a plunging type tripod constant velocity joint, and in particular to a structure of a mounting portion that is externally fitted and fixed to the outer cylinder of the joint.

[Conventional technology]

For example, plunging type tripod constant velocity joints used in front engine, front drive vehicles, and four-wheel independent suspension vehicles have an open end face of the outer cylinder that is part of the joint, so a flexible rubber boot is used. This is done to prevent grease from flowing out and at the same time protect the inside of the outer cylinder from collisions with pebbles and the intrusion of dust.

As shown in Figures 4 and 5, the basic structure of a plunging type tri-port constant velocity joint is that there are three shafts extending in the axial direction on the inner surface of an outer cylinder 2 that is open at one end and has a shaft 1 at the other end. Groove-like tracks 3 are formed at equal angles, and a driven shaft 4 inserted into the outer cylinder 2 from the open end supports a rolling roller 5 that fits inside each track 3, so that rolling rollers 5 are connected to both sides of each track 3. The outer circumferential surface of the roller 5 is formed into an arcuate surface, and the shaft 1 of the outer cylinder 2 and the driven shaft 4 are connected to be able to be relatively displaced in the axial direction and tilted at any angle.

Further, the rubber boot 6 that closes and protects the open end side of the outer cylinder 2 has a large-diameter attachment part 8 that fits onto the outer cylinder 2 at one end of the flexible part 7, and this attachment part 8 is attached to the outer periphery. It is fixed to the outer cylinder 2 with a tightened boot band 9, and at the other end of the flexible part 7, although not shown, it has a structure substantially similar to the above-mentioned mounting part 8, and is attached to the driven shaft 4.
It is formed with a small-diameter mounting part that is externally fitted and fixed to the main body.

By the way, in order to form the groove-like tracks 3 on the inner surface of the outer cylinder 2, the peripheral wall is pressurized and deformed inward at the positions between the tracks, and the outer surface has three grooves extending in the axial direction. 10 at equal angles.

Therefore, the large-diameter mounting portion 8 of the rubber boot 6 has a cross-sectional structure in which a thick portion 12 that fits into each groove 10 is provided between the thin portions 11 so that the inner surface thereof matches the outer shape of the outer cylinder 2. There is.

[Problem that the invention attempts to solve]

Fitting the large-diameter mounting portion 8 as described above onto the outer cylinder 2,
When fixed by tightening the boot band 9,
The thin part 11 is well tightened, but the thick part 12 has elasticity that increases in proportion to the thickness, so the tightening force becomes weak.

Therefore, when a torsional force is applied to the rubber boot 6 when tightening the boot band, driving, adjusting the operating angle, etc., as shown in FIG. Due to the elastic displacement of the position, a gap 13 is created between the outer cylinder 2 and the outer cylinder 2.

As described above, when the gap 13 is created, there is a problem that water and dirt enter the outer cylinder 2 from the outside in addition to grease leakage.

This invention was made in order to solve the above-mentioned problems, and the purpose is to provide a rubber boot in which there is no gap between the attachment part of the rubber boot and the fitting surface of the outer cylinder.

[Means for solving problems]

In order to solve the above problem, this invention embeds a core that is harder than the rubber boot in the thick part of the large diameter attachment part of the rubber boot, and the inner surface of this core is roughly shaped like a concave groove of the outer cylinder. The outer surface is formed into an arcuate surface that is approximately coaxial with the outer diameter of the mounting portion, and the inner and outer thicknesses of the thick portion divided by the center core are made uniform. It is.

[Effect]

The thick portion of the large-diameter mounting portion fitted onto the outer cylinder fits into the groove, and is fixed to the outer cylinder by tightening the boot band.

The thick part is divided into two parts, inside and outside, by a hard core buried inside, and the inner and outer wall thicknesses are approximately equal to the thinner part, so the elasticity of the entire periphery of the mounting part is approximately equal. The tension force caused by tightening the boot band becomes constant, and even if a torsional force is applied to the rubber boot, no gap will be created between the thick part and the outer cylinder.

〔Example〕

Embodiments of this invention will be described below with reference to FIGS. 1 to 3 of the accompanying drawings.

In addition, in FIGS. 1 to 3, parts that are the same as those in FIGS. 4 and 5 are given the same reference numerals, and explanations thereof will be replaced.

As shown in the figure, a core 21 made of a material harder than the rubber boot 6 is embedded inside the thick portion 12 of the large diameter attachment portion 8 of the rubber boot 6.

The inner surface of this core 21 facing the outer cylinder 2 has a concave groove 1.
0, and the outer surface is formed into an arcuate surface approximately coaxial with the outer diameter of the large diameter mounting portion 8,
It is buried at a position that divides the thick portion 12 into inner and outer parts.

By embedding the core 21, the rubber portion of the thick portion 12 is divided into an inner layer 22 and an outer layer 23, each having a uniform thickness.
2 and the outer layer 23 have approximately the same thickness as the thin-walled portion 11 in the large-diameter attachment portion 8, and therefore
When the outer periphery of the boot band 9 is tightened, the tightening force around the entire circumference becomes approximately constant.

For embedding the core 21 in the thick portion 12, methods such as integral molding or press-fitting can be adopted, and the material of the core 21 can be rubber or various synthetic resins that are harder than the rubber boots 6. Yes, center core 21
Even if the end portion is exposed on the end face of the thick portion 12 as shown in FIG. 1, the entire thick portion 12 is exposed as shown in FIG.
It may be embedded inside 2.

The rubber boot of this invention has the above-mentioned configuration, and when the large-diameter mounting portion 8 is fitted onto the outer cylinder 2 and fixed by tightening the boot band 9, the entire circumferential surface of the large-diameter mounting portion 8 is approximately It is tightened uniformly, and even if a torsional force is applied to the rubber boot 6, no gap is generated in the thick portion 12 due to elastic displacement.

〔effect〕

As described above, since this invention has the above-described configuration, it has the following effects.

(1) A core that is harder than the boot is incorporated into the thick part of the large-diameter attachment part of the rubber boot, and the thick part is divided into two parts, inside and out, so that each part has an equal thickness, so when tightening the boot band, the entire circumference is removed. The tension force is constant, and even if torsional force is applied to the rubber boot, no gap will occur between the outer cylinder and the thick part.

(2) Since there is no gap between the outer cylinder and the thick walled part, grease leakage and water and dirt from the outside can be prevented from entering the outer cylinder.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view of a joint using a rubber boot according to this invention, Fig. 2 is a longitudinal sectional side view of the same as above, Fig. 3 is a sectional view showing another example of the core buried part, and Fig. 4 is a conventional one. FIG. 5 is a longitudinal sectional front view of the joint using the rubber boots of 1. FIG. 5 is a longitudinal sectional side view of the same. 1...Shaft, 2...Outer cylinder, 3...Groove track,
4... Driven shaft, 5... Rolling roller, 6... Rubber boot, 7... Flexible part, 8... Large diameter mounting part, 9... Boot band, 10... Concave groove, 11... Thin wall portion, 12... Thick wall portion, 21 ... center core, 22 ... inner layer, 23 ... outer layer.

Claims (1)

[Scope of utility model registration request] A tripod that has a large diameter mounting part that is externally fitted and fixed to the outer cylinder of the tripod constant velocity joint, and this mounting part has a thick part that fits into three grooves provided at equal angles on the outer surface of the outer cylinder. In rubber boots for constant velocity joints, a core that is harder than the rubber boot is embedded in the thick part of the large diameter mounting part, and the inner surface of this core is shaped into an arcuate surface that is approximately equal to the concave groove shape of the outer cylinder, and the outer surface A rubber boot for a tripod constant velocity joint, characterized in that the sides are formed on arc-shaped surfaces of a center substantially coaxial with the outer diameter of a mounting part, and the inner and outer thicknesses of the thick part divided into two by the center core are made uniform.