JPH0725464Y2 - Mounting structure of rubber boot end in disc brake - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention provides a rubber boot that covers a piston of a disc brake and a slide pin of a caliper slide portion for the purpose of protecting them easily and easily. Moreover,
The present invention relates to a boot end mounting structure for mounting a rubber boot end in a highly reliable state.

[Conventional technology]

A disc brake that presses a friction pad with a hydraulically operated brake piston to make sliding contact with the disc causes the amount of protrusion of the brake piston from the cylinder to gradually increase as the pad wears. An elastic rubber boot is provided between the two, and this boot covers and protects the protruding portion of the piston from the cylinder.

Further, the floating disc brake has a slide portion for sliding the caliper in the disc axial direction between the caliper and the fixing member. The slide pin used for the slide portion also slides as the pad wears. Since it comes out from the pin insertion hole, it is performed by covering it with rubber boots.

One end of these rubber boots is fixed to a fixing object, that is, a boot for a piston is fixed to a caliper, and a boot for a slide pin is fixed to a member provided in a slide pin insertion hole. The slide pin insertion hole is provided in the fixing member when the slide pin is fixed to the caliper, but there is also one that fixes the pin to the fixing member. In this case, the pin insertion hole exists on the caliper side.

FIG. 4 shows an example of a conventional rubber boot mounting structure adopted for a caliper slide portion. Reference numeral 1 in FIG. 1 is a fixing member having a slide pin insertion hole 2. A slide pin 3 is fixed to a caliper and one end of which is inserted into the pin insertion hole 2, and a rubber boot 4 for pin protection is put on the outer circumference of the pin.

The rubber boot 4 is often provided with an annular groove on the inner diameter surface near the entrance of the slide pin insertion hole 2 and locked in the groove, but this structure is not excellent in workability and assemblability, so that it is shown in FIG. A metal or plastic retainer 5 is integrally bonded to the structure, that is, the end of the boot, and this retainer is provided with a hole 2
A structure for press-fitting into a seat hole 6 formed at the mouth portion of is adopted.

The same mounting structure tends to be used more and more for rubber boots for brake pistons.

[Problems to be solved by the device]

In the mounting structure described above, the inner diameter surface of the rubber boot end is in contact with the outer periphery of the slide pin 3, and the tip of the boot end in the press-fitting direction is in pressure contact with the bottom surface of the seat hole 6 into which the retainer is press-fitted, so that the inlet of the slide pin insertion hole is watertight. Sealed.

However, in the illustrated structure in which the seal portion between the fixed member 1 and the fixing member 1 is at the bottom of the seat hole, the flange 5a formed on the retainer
There is a problem that water or the like penetrates to the retainer press-fitting portion through the interface between the end surface of the fixing member 1 and the end face of this fixing member, and the retainer press-fitting portion is rusted. There was a problem that wasteful work of removing rust was required when replacing, and if the rust was severe, the retainer could not be removed and the fixing member had to be replaced. Such a problem naturally occurs also in the mounting portion of the rubber boot for the piston.

Therefore, this invention intends to provide a mounting structure for a rubber boot end that facilitates the fixing work of the boot end by using a retainer and eliminates the above-mentioned problems.

[Means for Solving the Problems]

In order to eliminate the above problem, this invention provides a second seat hole having a diameter larger than the diameter of the seat hole at the entrance of the seat hole into which the retainer is press-fitted, and further, a flange provided at one end of the retainer has a second seat hole. A rubber annular seal to be inserted into the second seat hole at a larger diameter than the seat hole diameter of the second seat hole, and the axial protrusion amount of the seal from the flange is made larger than the depth of the second seat hole. As a general rule, the seal is pressed against the bottom of the second seat hole.

[Action]

The annular seal is formed by press-contacting the bottom of the second seat hole, and the seal portion is formed between the flange of the retainer and the end surface of the fixing object (fixing member or caliper) with which the flange abuts rather than the retainer press-fitting portion. It is on the inlet side of the interface between. Therefore, the water or the like that has entered the interface portion is blocked at the hole bottom portion of the second seat hole and does not flow into the retainer press-fitting portion, and rusting of the retainer press-fitting portion is prevented.

〔Example〕

 1 to 3 show an embodiment of this invention.

FIG. 1 shows a structure for attaching the rubber boot 4 for a slide pin to a fixing member. As shown in the drawing, a shallow second seat hole 7 having a diameter larger than that of the seat hole 6 is provided at the entrance of the seat hole 6. Further, the retainer 5 and the flange 5a have a diameter larger than 7, and an annular seal 8 integral with the rubber boot 4 is provided on this flange portion. The seal 8 has such an outer diameter that it can be inserted into the second seat hole 7, and the axial dimension l shown in FIG. 2 is larger than the depth h of the second seat hole. Therefore, after press fitting, lh
Is the tightening margin, and the seal 8 is pressed against the hole seating surface of the second seat hole 7, and a seal portion different from the seal portion formed at the hole bottom portion of the seat hole 6 is formed at that portion.

FIG. 3 shows a mounting structure for fixing the rubber boot 9 for the brake piston to the caliper 10. Figure 11
Is a brake piston. Further, 12 is a cylinder provided in the caliper, and the retainer 5 is provided at the opening of this cylinder.
Seat hole 6 for press-fitting and second seat hole 7 having a larger diameter than that
And the diameter of the flange 5a at the end of the retainer 5 and the dimensions of the seal 8 provided on the flange portion are determined in the same manner as described above, and the seal portion is provided at the bottom of the second seat hole as in the case of FIG. Is causing.

The depth of the second seat hole is naturally set to a value that does not deteriorate the press-fit stability of the retainer.

〔effect〕

As described above, according to the present invention, one end of the rubber boot is fixed with good workability by using the press-fitting retainer, and the second seat hole is provided at the inlet portion of the seat hole for press-fitting the retainer and is provided on the flange portion of the retainer. Since the seal was pressed against the bottom surface of the second seat hole to prevent water and the like from entering the retainer press-fit portion, the problem of deterioration of the retainer attachment / detachment due to rusting of the retainer press-fit portion did not occur, facilitating maintenance, There is an effect that wasteful replacement of parts can be eliminated.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a boot end mounting structure of the present invention, FIG. 2 is a diagram showing a dimensional relationship before mounting, FIG. 3 is a sectional view of another embodiment, and FIG. 4 is a conventional mounting. It is sectional drawing which shows an example of a structure. 1 ... Fixing member, 2 ... Slide pin insertion hole, 3 ... Slide pin, 5 ... Retina, 5a ... Flange, 6 ...
Seat hole, 7 ... Second seat hole, 8 ... Annular seal, 9 ... Rubber boot, 10 ... Caliper, 11 ... Brake piston, 12
……Cylinder.

Claims (1)

[Scope of utility model registration request] 1. A retainer having a flange is integrally attached to one end of a rubber boot to be covered with a brake piston or a slide pin of a caliper slide as a protected object, and the retainer is attached to a seat hole on the fixing target side. In a mounting structure of a rubber boot end in a disc brake in which one end of the rubber boot is press-fitted and fixed in a state of being pressed against the object to be protected and the seat hole, a second diameter larger than the diameter of the seat hole is provided at the entrance of the seat hole. And a flange having a diameter larger than that of the second seat hole to form a rubber annular seal to be inserted into the second seat hole in the flange portion, and the axial projection of the seal from the flange. The seal to the second position with the amount larger than the depth of the second seat hole.
The mounting structure of the rubber boot end, characterized in that it is pressed against the bottom of the seat hole.