JPH0312986Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention is a vehicle disc brake in which a heat insulating material is provided at the tip of the piston, and a friction pad is pushed through a protective cover that covers the heat insulating material. Regarding.

[Conventional technology]

For disc brakes used in vehicles such as four-wheeled cars and motorcycles, the braking heat from the friction pads used for braking is transmitted to the piston and caliper, raising the temperature of the hydraulic fluid in the cylinder hole and causing the vapor lock phenomenon. In order to prevent this, various heat insulation measures have been studied, and one example is shown in Fig. 7.

A piston 3 is inserted into a cylinder hole 2 formed in a caliper 1 of a disc brake, and a distal end 3a of the piston 3 protruding from the cylinder hole 2 has a mounting recess 3c formed in a friction pad facing surface 3b.
A plate-shaped heat insulating material 4 is fitted with a front protrusion 4a protruding from the friction pad facing surface 3b.

The front surface 4b of the protrusion 4a is covered with a protective cover 5 whose periphery 5a is press-fitted onto the outer periphery of the tip 3a of the piston 3, and prevents the braking generated on the friction pad 7 due to sliding contact with the disc rotor 6. Heat is prevented from being transmitted to the piston 3 and caliper 1 by the protective cover 5 and the heat insulating material 4.

[The problem that the idea attempts to solve]

Since the protective cover 5 is assembled onto the piston 3 with a tightening margin in advance as described above, the ease of assembly is good, but due to repeated braking operations, the protective cover 5 may leave a void 8 inside. The outer periphery is struck and deformed by the action in the direction of arrow A, and as a result, the above-mentioned tightening margin is lost and the protective cover 5 becomes loose, creating a risk of forgetting to assemble or losing the protective cover 5 when replacing the friction pad 7.

Generally, the caliper 1 has a disc rotor 6.
Since a ceiling opening is provided in the bridge portion that spans the outer circumference of
In some cases, the heat insulating material 4 gets stuck between the two, degrading the performance of the heat insulating material 4 and causing abnormal wear.

Therefore, an object of the present invention is to provide a disc brake for a vehicle in which abnormal wear of the heat insulating material can be prevented with a protective cover.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes a ceiling opening in the bridge part of the caliper that straddles the outer periphery of the disc rotor, and a mounting recess formed in the surface facing the friction pad of the tip of the piston protruding from the cylinder hole of the caliper. In a disc brake for a vehicle in which a front protrusion protrudes from the surface facing the friction pad, a heat insulating material is fitted thereon, and the front surface of the protrusion is covered with a protective cover, there is a connection between the bridge part of the caliper and the cylinder hole. a heat insulating cover part that is fitted to the protective cover to cover the protruding part of the heat insulating material; a piston cover part that is fitted to cover the tip of the piston; a shielding portion wider than the hole, and fitting both covering portions to the protrusion of the heat insulating material and the tip of the piston to attach a protective cover, and placing the shielding portion in the storage recess of the caliper. The protective cover, which is loosely inserted and moves back and forth together with the piston during braking, protects the shielding part, which is loosely inserted into the caliper housing recess, even when the friction pad is fully worn out and at maximum forward movement. , the length is such that it does not slip out of the heat absorption recess.

[Embodiment]] Hereinafter, an embodiment of the present invention will be described based on FIGS. 1 to 5.

The disc brake 10 is connected to the first caliper 11.
Cylinder body 11a and second cylinder body 11
b is a piston facing type in which a bridge portion 11c spanning the outer periphery of the disk rotor 12 is connected by bolts 13, 13, and cylinder bodies 11a, 11b
A piston 15 made of synthetic resin is inserted through a corner seal 16 in a liquid-tight and movable manner into each cylinder hole 14 which is opened on the disk rotor 12 side.

A hydraulic chamber 17 is defined between the bottom of the cylinder hole 14 and the piston 15, and the cylinder body 11
A hydraulic fluid supply pipe 18 connecting the two hydraulic pressure chambers 17, 17 is disposed on the outer peripheral side of a, 11b, and
A union bolt 19 for introducing hydraulic fluid is connected to the first cylinder body 11a, and a union bolt 19 is connected to the second cylinder body 11a.
A bleeder screw 20 for air bleeding is screwed onto each of b.

A hanger pin 21 that passes through a ceiling opening 11d formed in the bridge portion 11c is inserted into both cylinder bodies 11a, 11b in the disk axial direction. Friction pads 22, 22 are suspended and are arranged opposite to each other with the disk rotor 12 in between, and arcuate storage recesses 11e are formed between the ceiling opening 11d and each cylinder hole 14, respectively. .

In each friction pad 22, a back plate 22b to which a lining 22a is fixed is fitted into a mounting recess 11f of each cylinder body 11a, 11b, which serves as a torque receiving part. , is pushed by the protective cover 24 that covers the heat insulating material 23 of the piston 15, and both linings 22a, 22
A is pressed against the disc rotor 12 to perform a braking action.

Each piston 15 has a cylinder body 11 on the outer periphery of the tip 15a protruding from the cylinder hole 14.
dust boots 25 fitted between a and 11b
and an annular groove 15c for locking the three locking claws 24c of the protective cover 24, and a mounting recess 15e is formed in the friction pad facing surface 15d. The disc-shaped heat insulating material 23 is placed in the recess 15e, and the front protrusion 23a
is fitted so as to protrude from the friction pad facing surface 15d.

The protective cover 24 also includes a heat insulating material cover portion 24a that is fitted to cover the entire protrusion 23a of the heat insulating material 23, and a piston cover portion 24b that is fitted to the tip portion 15a of the piston 15 to cover the entire portion. , a shielding part 24d wider than the cylinder hole 14 is formed by bending the tip of a flange 24c that continues in a fan shape from the outer periphery of the piston cover part 24b toward the outer periphery of the disk rotor, and the flange 24c includes:
The locking pawl 24e that is locked in the annular groove 15c of the piston 15 is provided in a protruding L-shape.

The cover 24 has both cover portions 24a and 24b.
are fitted into the protrusion 23a of the heat insulator 23 and the tip 15a of the piston 15, respectively, and the locking claw 24e
is attached to the annular groove 15c, and the shielding part 2
4d is loosely inserted into the storage recess 11e of the caliper 11, covering the outer periphery of the dust boot 25.

The blocking portion 24d prevents not only the back and forth movement of the piston 15 during braking but also the lining 22 of the friction pad 22.
The shielding portion 24d is provided with a sufficient length so that even when the piston 15 is fully worn out and moves forward at its maximum, it will not slip out of the housing recess 11e.
The dust boot 25 covered by the ceiling opening 11
The shielding part 24d prevents direct hits from water, dirt, etc. that enter from d.
protection, improving durability.

Both cover portions 24a and 24d are fitted tightly together with the protrusion 23a of the heat insulating material 23 and the tip end 15a of the piston 15 without creating a gap as in the conventional case, so that the braking effect is improved. Even if it is hit repeatedly, it is unlikely to be deformed, and together with the shielding portion 24d, it prevents water and dirt from entering between the protective cover 24 and the piston 15, so that abnormal wear will not occur in the heat insulating material 23. Therefore, the insulation performance can be fully demonstrated for a long period of time.

Furthermore, due to the above-described installation, the protective cover 24 is
This prevents the friction pad from being forgotten or lost when replacing it, and furthermore, in this embodiment, the locking pawl 24e protruding from the flange 24c is locked into the annular groove 15b of the piston 15, making assembly more reliable. It is being

FIG. 6 shows another embodiment in which the present invention is applied to a floating caliper type disc brake.
The heat insulating material 23 and the protective cover 24 are formed in the same manner as in the above embodiment.

The caliper 30 connects a cylinder body 30a on the action side having a cylinder hole 31 and a reaction part 30c having a reaction claw 30b to the disc rotor 12.
A ceiling opening 30e is formed in the bridge part 30d, and the bridge part 30d and the cinder hole 3
A storage recess 30f is provided between the cylinder hole 31 and the cylinder hole 31, and a cup-shaped piston 32 is inserted into the cylinder hole 31.

The piston 32 has an annular groove 32b for the dust boot 25 and an annular groove 32c for the locking pawl 24e on the outer periphery of a tip 32a protruding from the cylinder hole 31, and a friction pad opposing surface 35d. ,
A mounting recess 35e for fitting the heat insulating material 23 is formed, and the protective cover 24 is installed by covering the front surface of the protrusion 23a of the heat insulating material 23 that protrudes from the friction pad facing surface 32d in the same manner as in the previous embodiment. be done.

[Effect of idea]

As explained above, in the present invention, a storage recess is formed between the bridge part of the caliper forming the ceiling opening and the cylinder hole into which the piston is inserted.
A protective cover disposed at the front of the heat insulating material includes a heat insulating material cover part that is fitted to cover the protruding part of the heat insulating material, a piston cover part that is fitted to cover the tip of the piston, and a cylinder hole. A protective cover is attached by fitting both covering parts to the protrusion of the heat insulating material and the tip of the piston, respectively, and the shielding part is loosely inserted into the storage recess of the caliper. Because the protective cover is inserted into the piston, even if it is hit by repeated braking, the protective cover is unlikely to deform, and together with the shielding part, it prevents water and dirt from entering between the protective cover and the piston. Sufficient heat insulation performance can be exhibited for a long period of time without causing abnormal wear on the material, and it also prevents forgetting to assemble or losing the protective cover when replacing the friction pad.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention,
Fig. 1 is a sectional view of Fig. 2, Fig. 2 is a front view of the disc brake, Fig. 3 is a plan view, Fig. 4 is a sectional view of Fig. 3, and Fig. 5 is a sectional view of the disc brake. FIG. 6 is a cross-sectional front view of a disc brake showing another embodiment, and FIG. 7 is a cross-sectional front view of essential parts of a conventional disc brake. 10... Disc brake, 11... Caliper, 11a... First cylinder body, 11b...
2nd cylinder body, 11c...Bridge part, 1
1d...Ceiling opening, 11e...Storage recess, 12
... Disc rotor, 14 ... Cylinder hole, 15
...Piston, 15a...Tip, 15d...Friction pad opposing surface, 15e...Mounting recess, 21...
Hanger pin, 22...Friction pad, 23...Insulating material, 23a...Protrusion, 24...Protective cover,
24a...Insulating material cover part, 24b...Piston cover part, 24c...Flange, 24d...Shielding part,
24e...Latching claw, 25...Dust boots.

Claims (1)

[Scope of utility model registration request] A ceiling opening is provided in the parity of the caliper that straddles the outer periphery of the disc rotor, and the protruding part of the front part is inserted into the mounting recess formed in the friction pad facing surface of the piston tip protruding from the cylinder hole of the caliper. In the disc brake for a vehicle, the disc brake has a heat insulating material fitted therein, and a protective cover covers the front surface of the protruding part, wherein a storage recess is formed between the bridge part of the caliper and the cylinder hole, and the protective cover is covered with a housing recess. , forming a heat insulating material cover part fitted to cover the protrusion of the heat insulating material, a piston cover part fitted to cover the tip end of the piston, and a shielding part wider than the cylinder hole, A vehicle disc characterized in that a protective cover is attached by fitting both covering parts to a protrusion of a heat insulating material and a tip end of a piston, respectively, and the shielding part is loosely inserted into a storage recess of the caliper. brake.