JPH08159187A - Brake lining - Google Patents

Abstract

PURPOSE: To provide a brake lining capable of effectively absorbing frictional vibration. CONSTITUTION: A brake lining 1 is used for a drum brake device to be brought in frictional-contact with the inner surface of a cylindrical brake drum to be rotated, and for generating braking force, and it is provided with friction members 2 provided with a surface 22 to be brought in frictional-contact with the inner surface of the brake drum. A recessed part 24 is formed on the surface 22 on the opposite side to the surface to be brought in frictional-contact with the inner surface in the friction member 2, and a damping material 3 is fitted in the recessed part 24.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake lining in a drum type brake device for an automobile.

[0002]

2. Description of the Related Art In a drum type brake device for an automobile, as generally shown in FIG. 3, a pair of brake shoes b are arranged inside a brake drum a, and each brake shoe b is provided with a rim c. The rim is composed of a brake lining d fixed to the outer peripheral surface of the rim with rivets or bolts, nuts, etc. Also, one end of each rim c is rotatably supported by an anchor pin e and a wheel cylinder is provided between the other ends. It is configured with f interposed. During braking, the wheel cylinder f is extended by fluid pressure from a master cylinder (not shown) or the like, and each rim c is pressed outward with the anchor pin e as a fulcrum. As a result, the contact surface of the brake lining d fixed to the rim makes frictional contact with the inner surface of the brake drum a and exerts a braking force on the brake drum a.
When releasing the braking, the fluid pressure from the master cylinder is released and the pressing force of the wheel cylinder f is released. As a result, the rim returns to the original operating position by the restoring force of the return spring g, and the contact surface of the brake lining d is separated from the inner surface of the brake drum a.

In the drum type brake device having the above-mentioned structure, there is a problem that brake squeal occurs due to frictional vibration of the brake lining due to frictional contact during braking, which is one of the causes of noise. In order to prevent the noise caused by the squeal of the brake, it is necessary to prevent the frictional vibration of the brake lining. To this end, it is effective to increase the elasticity of the friction material itself that forms the brake lining to improve the vibration damping characteristics of the brake lining, but since the friction material of the brake lining is required to have high wear resistance, It is necessary to increase the hardness, and there is a limit to the increase in elasticity of the friction material itself. Therefore, as a measure for preventing such frictional vibration of the brake lining, conventionally, as shown in FIG. 4, a thin vibration absorbing material h is interposed between the opposing surfaces of the brake lining d and the rim c to fix the brake lining d. A device that absorbs vibration, a rim c of the brake lining d as shown in FIG.
The vibration absorbing material i is integrally formed with the brake lining on the side opposite to and the vibration absorbing material i is fixed to the rim c by the fixing members j and k to absorb the frictional vibration of the brake lining (the same application as the applicant of the present application. Practical application by humans 2-1062
59), and as shown in FIG. 6, the viscoelastic material 1 is interposed between the opposing surfaces of the brake lining d and the rim c without a gap, and the release agent m is interposed at the interface between the rim and the viscoelastic material. What is configured to absorb the frictional vibration of the brake lining (Practical application Hei 2-106
258), etc. have been proposed.

[0004]

However, in any of the above solutions, it is not possible to thicken the vibration absorbing material in order to maintain the crimping force of the brake shoe during braking, and the frictional vibration of the brake lining is effectively absorbed. It was difficult to do so, and the sufficient effect was not obtained.

The present invention has been made in view of the above problems in the prior art, and an object thereof is to provide a brake lining which can effectively absorb frictional vibration.

[0006]

In order to achieve the above object, the present invention provides a brake lining in a drum type brake device for generating a braking force by bringing a brake lining into frictional contact with the inner surface of a rotating cylindrical brake drum. A friction material having a surface that makes frictional contact with the inner surface of the brake drum, wherein the friction material has a concave portion formed on a surface opposite to the frictional contact surface, and a vibration absorbing material is mounted in the concave portion. It is configured.

[0007]

When braking, the contact surface of the friction material comes into frictional contact with the inner surface of the brake drum to exert a braking force on the brake drum.
The frictional vibration of the friction material generated at this time is efficiently absorbed and attenuated by the relatively thick vibration absorbing material mounted in the recess.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The brake lining of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a brake lining 1 of the present invention and a state in which the brake lining 1 is attached to a rim. The brake lining 1 is composed of a friction material 2 and a vibration absorbing material 3, and has a plurality of mounting holes, which will be described later, provided in the friction material 2, for example, a bolt 4 and a nut 5 or a fixing tool such as a rivet, which is a known method. It is fixed to the rim 6 of the shoe.

The friction material 2 is formed with a surface 21 that makes frictional contact with the inner surface of the brake drum, a surface 22 that faces the rim on the side opposite to the frictional contact surface, and a predetermined distance along the peripheral edge of the friction material 2. The above-mentioned plurality of mounting holes 23 are provided, and this surface 22 has the mounting holes 2 as shown in the plan view of FIG.
A recess 24 is formed at a position separated from 3. The size of the concave portion 24 can be appropriately determined by design in consideration of the type of the vibration absorbing material, the frequency of use of the brake lining, etc., which will be described later. The friction material 2 can be molded from a friction / wear adjusting material made of an organic material, an inorganic material, or a metal material using an inorganic material as a base material, and a binder for binding and molding these components, as in the conventional case.

A vibration absorbing material 3 having a shape corresponding to the shape of the recess 24 is mounted in the recess 24. As described above, the vibration absorbing material 3 is mounted at a position separated from the mounting hole 23 for the friction material, and the fixed portion of the brake lining 1 and the vibration damping portion by the vibration absorbing material can be separated from each other. The shape can be relatively thicker than the above. Therefore,
The frictional vibration of the brake lining during braking can be sufficiently absorbed and damped. In addition, the vibration absorbing material 3 is provided on the surface 2 of the friction material 2 before the brake lining 1 is assembled to the rim 6.
2 is attached to the friction material 2 with a step portion 31 (tightening allowance), but when the brake lining 1 is assembled to the rim 6 and tightened with a fixing tool, the step portion 31 is compressed by the rim 6. As a result, the outer surface of the rim 6 is flush with the outer surface.
Therefore, the vibration absorbing material 3 is brought into close contact with the friction material 2 by its elastic force, and the frictional vibration energy of the brake lining can be absorbed more efficiently. Since the vibration absorbing material 3 is subjected to high temperature heat history due to frictional heat, it should be molded from synthetic rubber having good thermal stability, moldability and elasticity, organic resin material such as phenol resin, or phenol resin containing metal powder. However, other materials may be used as long as they are excellent in moldability, elasticity and thermal stability.

In the manufacture of the brake lining 1,
The friction material 2 is first molded, and the vibration absorbing material 3 is formed in the recess 24 of the friction material 2.
It is manufactured by filling and integrally molding. As another method, the friction material 2 and the vibration absorbing material 3 may be separately molded, and the vibration absorbing material 3 may be put into the friction material 2 when the brake lining 1 is assembled to the rim 6.

In the above structure, at the time of braking, the surface 21 of the friction material 2 makes frictional contact with the inner surface of the brake drum to exert a braking force on the brake drum. The frictional vibration of the friction material generated at this time is efficiently absorbed and damped by the relatively thick vibration absorbing material 3 mounted in the recess 24.

[0014]

As described above, according to the present invention, the surface 22 of the friction material is
Since the concave portion 24 is formed at a position separated from the plurality of mounting holes and the vibration absorbing material is mounted in the concave portion, the vibration absorbing material can have a relatively thicker shape than the conventional vibration absorbing material. Therefore, it becomes possible to sufficiently absorb and damp the frictional vibration of the brake lining during braking, effectively suppress the brake squeal, and increase the degree of freedom in selecting the material of the vibration absorbing material. Further, the vibration absorbing material 3 has a step portion 31 (tightening margin) with respect to the surface 22 of the friction material 2 before the brake lining 1 is assembled to the rim 6, while the brake lining 1 is attached to the rim 6. In the state of being tightened by the assembling fixture, the step portion 31 is compressed and becomes flush with the outer peripheral surface of the rim 6, and the elastic force of the step portion 31 makes close contact with the friction material 2, so that the friction vibration energy of the brake lining is further increased. It can be absorbed efficiently.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a brake liner body according to the present invention and a state in which the brake liner is attached to a rim.

FIG. 2 is a plan view of the friction material as seen from the side facing the rim.

FIG. 3 is a diagram schematically illustrating a general configuration of a drum brake device for an automobile.

FIG. 4 is a view showing a conventional measure for preventing frictional vibration of a brake lining, and is a view showing a state in which a thin vibration absorbing material is interposed between opposed surfaces of the brake lining and the rim.

FIG. 5 is a diagram showing a measure for preventing frictional vibration of a conventional brake lining, showing a state in which a vibration absorbing material is integrally formed with the brake lining and the vibration absorbing material is fixed to a rim by a fixing member. .

FIG. 6 is a view showing a conventional measure for preventing frictional vibration of a brake lining, and is a view showing a state in which a viscoelastic material is interposed between the opposing surfaces of the brake lining and the rim without a gap.

[Explanation of symbols]

1 brake lining, 2 friction material, 3
Absorbing material, 6 rims, 21 friction contact surface, 22 friction contact surface opposite side,
23 mounting holes, 24 recesses, 3
1 step

Claims (3)

[Claims] 1. A friction lining having a surface which makes frictional contact with the inner surface of the brake drum, wherein the inner surface of a rotating cylindrical brake drum is frictionally contacted with the brake lining to generate a braking force. A brake lining comprising a material, the friction material having a recess formed on a surface opposite to the surface in frictional contact, and a vibration absorbing material being mounted in the recess. 2. The brake lining according to claim 1, wherein the vibration absorbing material is mounted at a position spaced from a plurality of mounting holes for mounting the brake lining to a rim of a brake shoe. 3. The brake lining according to claim 1, wherein the vibration absorbing material is mounted with a step provided on a surface of the friction material where the concave portion is formed.