JPH022985Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a dust boot that prevents muddy water, dust, etc. from entering from the outside between a cylinder and a piston of a disc brake, for example.

[Conventional technology]

For example, in a disc brake, as shown in Fig. 3, a piston 3 that pushes the brake pads is movably fitted into a cylinder 2 formed in the body 1 of the caliper, and muddy water and dust are removed between the cylinder 2 and the piston 3. Dust boots 4 are installed to prevent the intrusion of foreign substances.

The dust boot 4 is made of a flexible material such as rubber, and is pressed outwardly by an elastic ring 6 and fitted into a circumferential groove 5 with a rectangular cross section, which is recessed in the inner circumference near the open end 2a of the cylinder 2. The mating outer thick part 4a
and an inner thick part 4 tightly attached to the outer periphery of the piston 3.
b, and a bellows-shaped flexible part 4c connecting the inner thick part 4b and the outer thick part 4a, and the flexible part 4c expands and contracts according to the reciprocating movement of the piston 3. This seals the space between the cylinder 2 and the piston 3.

[Problem that the invention attempts to solve]

However, in the case of the above structure, since the area between the open end 2a of the cylinder 2 and the circumferential groove 5 is exposed, rust will occur due to adhering muddy water, etc., and the rust will eventually progress to the circumferential groove 5, making it difficult to seal. There is a concern that it may damage the

Therefore, an object of the present invention is to provide a dust boot that seals the circumferential groove to prevent the occurrence of rust and improves sealing performance.

[Means for solving problems]

To achieve the above object, the present invention provides a seal between an outer cylinder and an inner cylinder that move relatively reciprocally, and a thick outer part that fits into a circumferential groove recessed in the inner periphery near the open end of the outer cylinder. , a dust boot for a brake device having an inner thick part tightly attached to the outer periphery of the inner cylinder and a flexible part connecting the inner thick part and the outer thick part; A lip part that is in close contact with the inner circumferential wall of the outer cylinder on the end side is extended from the flexible part, and a sealant is sealed in the cavity formed between the lip part and the outer thick part. There is.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. In the figures, the same elements as those in the conventional example will be explained using the same reference numbers.

The dust boot 10 is located at the open end 2a of the cylinder 2.
An outer thick portion 10a is pressed and fitted into a circumferential groove 5 recessed on the inner periphery of the piston 3 by being pressed by the elastic ring 6, and an inner side portion 10a is tightly fitted into a circumferential groove 11 recessed on the outer periphery of the piston 3. A bellows-shaped flexible portion 10 that connects the thick portion 10b, the outer thick portion 10a, and the inner thick portion 10b.
c, and a lip portion 10d that extends from the flexible portion 10c and comes into close contact with the inner circumferential wall of the cylinder 2 on the side of the open end 2a of the cylinder 2 rather than the circumferential groove 5 of the cylinder 2. Part 10d is connected to cylinder 2
Grease 13 is sealed as a sealant in a cavity 12 formed between the lip portion 10d and the outer thick portion 10a in close contact with the inner circumferential wall of the lip portion 10d.

With this configuration, the lip portion 10
d and the grease 13 seal the circumferential groove 5 of the cylinder 2, preventing muddy water from entering and preventing rust from forming.

In the above embodiment, the dust boot according to the present invention was installed between the cylinder and piston of a disc brake, but the present invention can be applied to a dust boot of a wheel cylinder, a dust boot of a sliding pin of a disc brake, etc. can do.

[Effect of idea]

As described above, the present invention includes a thick outer wall portion that seals between an outer cylinder and an inner cylinder that move relatively reciprocally, and that fits into a circumferential groove recessed in the inner periphery near the open end of the outer cylinder; In a dust boot for a brake device, the dust boot has an inner thick part that is tightly attached to the outer periphery of the inner cylinder, and a flexible part that connects the inner thick part and the outer thick part. A lip part that tightly contacts the inner circumferential wall of the side outer cylinder is extended from the flexible part, and a sealant is filled in the space formed between the lip part and the outer thick part, so that muddy water does not enter the circumferential groove. etc., and prevents the occurrence of rust and improves sealing performance.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention,
Figure 1 is a sectional view showing how the dust boot is installed.
FIG. 2 is a perspective view of the dust boot, and FIG. 3 is a sectional view showing a conventional dust boot installed state. 1...Canaripa body, 2...Cylinder, 2a
... Cylinder opening end, 3 ... Piston, 5 ... Circumferential groove, 6 ... Elastic ring, 10 ... Dust seal,
10a...outer thick part, 10b...inner thick part,
10c...Flexible part shaped like a bellows, 10d...Lip part, 11...Concave groove, 12...Space, 13...Grease.

Claims (1)

[Scope of utility model registration request] Seals between the outer and inner cylinders that move relatively back and forth,
an outer thick part that fits into a circumferential groove recessed in the inner periphery near the open end of the outer cylinder; an inner thick part that is tightly attached to the outer periphery of the inner cylinder; and the inner thick part and the outer wall thickness. In the dust boot for a brake device, the dust boot for a brake device has a lip part extending from the flexible part and closely contacting the inner circumferential wall of the outer cylinder on the open end side of the circumferential groove. A dust boot for a brake device, characterized in that a sealing agent is sealed in a cavity formed between the outer thick part and the outside thick part.