JPH07208516A - Shim for disc brake - Google Patents

Abstract

PURPOSE:To realize effective prevention of a brake squeak by facilitating change of relative position to a brake pad in a shim for a disc brake to be fixed by hooking claw parts to the brake pad. CONSTITUTION:Claw parts 22a to 22d to be hooked to a back plate 34 of a brake pad 30 are provided on a main body 22 of a shim 20. Fluoro rubbers 24a to 24d as low frictional members are arranged on respective back plate 34 contact surfaces with the claw parts 22a to 22d, so that the shim 20 may easily change its relative position to the brake pad 30 in relation to self-excited vibration of the brake pad 30, to be generated by taking the rotational direction of a direction, namely, the longitudinal direction of the brake pad 30 as the amplifying direction, and causing the brake squeak when a friction member 32 of the brake pad 30 is brought in contact with the disc rotor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake shim, and more particularly to a disc brake shim fixed by hooking a claw portion on a brake pad.

[0002]

2. Description of the Related Art Conventionally, in order to prevent an abnormal noise called squeal generated when a disc brake is braked, a disc brake shim (such as a metal plate) between a brake pad 10 and a piston 12 (see FIG. 3). Hereinafter, there is known a configuration in which the shim 14 is simply provided.

As for the structure of the disc brake, for example, taking a vehicle brake as an example, a piston 12 is arranged in a caliper 16 supported on the vehicle body side, and the piston 12 is arranged.
It is general that the brake pad 10 is pressed against the disc rotor 18 that rotates integrally with the wheel by using.

At this time, sliding loss occurs due to friction between the brake pad 10 and the disc rotor 18, and the braking force is obtained by the loss.
The friction between 0 and the disk rotor 18 is not always smooth and uniform, and microscopic vibration occurs between the two during braking.

The cause of the above-mentioned squeal is this vibration. Particularly, the vibration generated between the brake pad 10 and the disc rotor 18 is in the vicinity of the natural frequency of the system of the entire brake mechanism including the piston 12, the caliper 16 and the like. If it occurs, it will be recognized as an abnormal sound.

In this case, when the shim 14 is interposed between the brake pad and the piston 12 as shown in FIG. 3, the friction coefficient between the piston 12 and the brake pad 10 is reduced, and the both are relatively easy. It is possible to change the relative position. Therefore, the vibration generated in the brake pad 10 is damped between the brake pad 10 and the piston 12, the shim 14 does not intervene, and the piston 12 and the brake pad 10 are substantially integrated. Vibration is less likely to be transmitted to the piston 12 as compared with the case where the piston 12 is present.

Further, when the brake pad 10 and the piston 12 change their relative positions via the shims 14 in this way, the contact state between the brake pad 10 and the disc rotor 18 at the time of braking changes, which causes In some cases, the frequency of the generated vibration and the natural frequency of the brake mechanism are greatly different from each other, and as a result, abnormal noise is prevented.

By the way, it is effective to dispose the shim 14 between the brake pad 10 and the piston 12 to prevent the brake squeal, as described above.
This is because the piston 12 and the piston 12 can change their relative positions. Therefore, from the viewpoint of preventing the brake squeal, the smaller the friction coefficient of the shim 14, the better.

Japanese Utility Model Laid-Open No. 4-107533 discloses a disc brake shim in which a ceramic material is dispersed on the front and back sides, paying attention to such a point. The contact surface between the brake pad and the shim and the contact surface between the shim and the piston ensure excellent sliding characteristics, thereby obtaining excellent damping characteristics and effectively preventing the brake squeal. .

[0010]

However, in the disc brake shim, as shown in FIG. 3, the claw portions 14a to 14d formed integrally with the main body are normally attached to the brake pad and assembled. Therefore, even when a low coefficient of friction is secured on the front and back surfaces as in the conventional shim, the shim 14 is equivalent to being integrally fixed in relation to the brake pad 10, and a smooth surface is obtained. It was not possible to fully enjoy the resulting effect.

Further, in such a structure, when the brake pad 10 vibrates, the stress is a specific claw portion 14a.
14d concentrates on the shim 14, causing the shim 14 to warp. As a result, the contact area between the shim 14 and the brake pad 10 and between the shim 14 and the piston 12 is reduced, so that the sliding characteristics are deteriorated, and therefore the brake squeal prevention effect is obtained. It also had a problem that

The present invention has been made in view of the above-mentioned points, and the above-mentioned problems are solved by disposing a low friction member on the brake pad contact surface of the claw portion provided to be locked on the brake pad. An object is to provide a disc brake shim that solves the problem.

[0013]

DISCLOSURE OF THE INVENTION The above object is to provide a disc brake shim having a pawl portion provided to be hooked on a brake pad for a disc brake, in which at least the friction pad has a low friction. This is achieved by a disc brake shim provided with a member.

[0014]

In the disc brake shim according to the present invention, the claw portion engages the disc brake shim with the brake pad. At this time, the low friction member is always interposed at the contact portion between the claw portion and the brake pad. The low friction member allows the relative position of the disc brake shim and the relative position of the disc brake shim to change with good sliding characteristics even when the disc brake shim is hooked on the brake pad.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall view (FIG. 1A) showing the structure of a disc brake shim (hereinafter simply referred to as a shim) 20 according to an embodiment of the present invention, and a side view of the main part (same as FIG. Figures (B) and (C)) are shown.

The shim 20 is a member disposed between the brake pad 30 and a piston (not shown) in order to allow relative displacement between the brake pad 30 and the piston during braking to prevent squeaking of the brake. The same as the conventional shim 14 shown in FIG.

The brake pad 30 is joined to the not-shown disc rotor to exert a braking force by friction, and the brake pad 3 is joined to the friction member 32.
And a back metal 34 that secures the strength required for zero.

In the present embodiment, the brake pad 30
The shim 20 is arranged to secure good sliding characteristics and appropriate durability in a state where it is arranged between the piston and the piston.
The main body 22 is made of stainless steel. This body 22
Includes claw portions 22a to 22d configured to be hooked on the back metal 34 of the brake pad 30.

On the contact surfaces of the claw portions 22a to 22d with the back metal 34, there are fluororubber 24a corresponding to the above-mentioned low wear member.
.About.24d are provided. This fluororubber 24a-2
4d can be formed by baking Teflon on the claw portions 22a to 22d or by bonding Teflon with an adhesive.

By the way, when the disc brake is constructed by using the brake pad, it is desirable that the contact position of the brake pad with respect to the disc rotor rotating integrally with the wheel is as close to the outermost diameter of the disc rotor as possible. This is because it is advantageous to secure a large braking torque by generating a frictional force near the outermost diameter of the disc rotor.

On the other hand, in the disc brake, the brake pad is positioned as a consumable material for the purpose of ensuring maintainability, etc., and when the disc rotor and the friction material slide, the friction material is actively worn to provide a braking force. It is a configuration to secure. Therefore, in order to obtain practical durability, it is necessary to sufficiently secure the wear allowance of the friction material.

For this reason, conventionally, as the shape of the brake pad, those having different vertical and horizontal lengths have been adopted as shown in FIG. 3, and the longitudinal direction thereof is matched with the rotation direction of the disc rotor for use. Is commonly used. With this configuration, the contact area between the disc rotor and the brake pad can be ensured to be relatively large near the outermost diameter of the disc rotor.

The shim 20 of this embodiment shown in FIG. 1 has a vertically and horizontally long shape, which is adapted to the shape of the brake pad 30 formed by having the vertically and horizontally different shapes for the above reason. The claws 22a to 22d are provided on the upper and lower sides of the shim 20 in FIG. 1 because the gripping force by the claws 22a to 22d is directly regulated when the brake pad 30 and the shim 20 are relatively displaced in the longitudinal direction. This is to avoid acting as force.

In particular, the shim 20 of this embodiment has a claw portion 22a.
-22d fluorocarbon rubber 24a-24d on the contact surface of the back metal 34
In this configuration, the relative displacement of the brake pad 30 and the shim 20 with respect to the longitudinal direction can be performed extremely easily as compared with the conventional shim.

Therefore, in the disc brake including the brake pad 30 and the shim 20, the brake pad 30 is pressed toward the disc rotor (not shown) during braking, and as a result, the rotation direction of the disc rotor is oscillated by the brake pad 30. When self-excited vibration in the direction of, that is, self-excited vibration in which the longitudinal direction of self is the direction of amplitude occurs, the relative position between the shim 20 and the piston (not shown) changes, and the shim 20 and the brake pad 30 The relative position with will also change easily.

That is, the self-excited vibration generated in the brake pad 30 is damped and absorbed by the shim 20, and it becomes difficult for the self-excited vibration to reach the piston. Therefore, it is difficult to transmit the self-excited vibration to the entire brake mechanism. As a result, it is possible to effectively suppress the generation of brake squeal that is noticeable to a person.

Further, in the structure in which the relative position between the brake pad 30 and the shim 20 can be easily changed as described above, the position on the brake pad 30 which receives the pressing force generated by the piston is also likely to change. In this case, the self-excited vibration of the brake pad 30 is unlikely to continue to maintain the frequency around the natural frequency of the brake mechanism, and this is effective in continuously preventing the brake squeal.

As described above, the shim 20 of the present embodiment can easily change the relative position with respect to the brake pad 30 by the action of the fluororubbers 24a to 24d arranged on the claw portions 22a to 22d. As compared with the disc brake shim, the squeal of the brake can be prevented more effectively.

According to the shim 20 having the above structure, the claw portion 22a is formed.
The sliding resistance between ~ 22d and the back metal 34 decreases, and the shim 2
It is possible to displace the relative position in a predetermined direction with 0 and the back metal having good sliding characteristics.

FIG. 2 shows a shim 4 according to another embodiment of the present invention.
0 front view (the same figure (A)) and side view (the same figure (B))
Indicates. The shim 40 shown in the figure is the shim 2 shown in FIG.
It is characterized in that the main body 22 of No. 0 is used and the fluororubber 42 is arranged on the entire surface of the back metal contacting surface.

In such a structure, the shim 20 described above is used.
Compared with, the relative position with the brake pad 30 can be changed more easily, and the self-excited vibration generated in the brake pad 30 can be absorbed and damped more effectively. Therefore, according to the shim 40 of this embodiment, the squeal of the brake can be prevented more effectively.

As the low friction member, it is possible to apply oils and fats such as grease in addition to the fluororubber represented by Teflon. However, when using such oils and fats, it is necessary to consider the sticking and drying due to frictional heat generated during braking, and it is necessary to select the oil and fat having excellent sticking drying resistance.

[0033]

As described above, according to the present invention, although the disc brake shim is hooked on the brake pad by using the claw portion, the relative position between the brake pad and the disc brake shim is improved. It can be varied under sliding properties. Therefore, the vibration generated in the brake pad during braking is appropriately damped not only between the disc brake shim and the wheel cinder 12 but also between the brake pad and the disc brake shim, and as a result, the specific pawl portion is damped. The feature is that the concentration of stress on the brake can be relieved, and an excellent effect of preventing squeal of the brake can be enjoyed as compared with the conventional disc brake shim.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a disc brake shim that is an embodiment of the present invention.

FIG. 2 is an overall configuration diagram of a disc brake shim that is another embodiment of the present invention.

FIG. 3 is a diagram for explaining general effects of a conventional disc brake shim.

[Explanation of symbols]

 10,30 Brake pad 12 Piston 14,20,40 Shim 16 Caliper 18 Disc rotor 22 Main body 22a-22d Claws 24a-24d, 40 Fluorine rubber

Claims (1)

[Claims] 1. A disc brake shim comprising a pawl portion provided to be hooked on a brake pad for a disc brake, wherein a low friction member is disposed at least on a brake pad contact surface of the pawl portion. Shim for disc brakes.