JPH0219622Y2 - - Google Patents

Description

[Detailed explanation of the invention] A. Purpose of the invention (1) Industrial application field The present invention is a disc brake for a vehicle, in particular, a brake disc that straddles a brake disc and first and second friction pads facing each other on both sides thereof. A first and second pinching arm of the brake caliper is disposed in the brake caliper, and a piston capable of bringing the first friction pad into pressure contact with one side of the brake disc is slidably provided on the first pinching arm, and The reaction causes the second
The brake caliper is slidably provided on a fixed bracket so that the pinching arm presses the second friction pad against the other side of the brake disc, and when the friction pad wears out beyond a certain value, it slides against the side of the brake disc. This invention relates to an improvement in a device equipped with an alarm sound generating piece.

(2) Conventional technology Conventionally, in such a disc brake, the base end of the alarm sound generating piece was fixed to the back surface of the back plate of the first friction pad, and the free end was made to protrude from the front face of the back plate and face the side surface of the brake disc. (For example, see Japanese Utility Model Publication No. 61-12423).

(3) Problems to be solved by the invention However, in the disc brake having the above configuration, the warning sound generating piece is pressed against one side of the brake disc only by the displacement due to wear of the first friction pad. When the pads have little wear, the contact pressure of the warning sound generating piece with the brake disc is low, resulting in a problem that the emitted warning sound is small and difficult to hear.

An object of the present invention is to provide the disc brake that can solve the above problems.

B. Structure of the invention (1) Means for solving the problem The present invention is characterized in that the alarm sound generating piece is formed into a substantially U-shape by an elastic plate, one end of which is fixed to the back plate of the first friction pad, and The other end is a free end and is opposed to one side of the brake disc, and between the middle part of this warning sound generating piece and the brake caliper, a first
The first friction pad due to wear exceeding a certain value on both second friction pads.
The present invention is characterized by comprising a cam mechanism that presses the intermediate portion of the warning sound generating piece in response to relative displacement between the friction pad and the brake caliper and slides its free end against one side of the brake disc.

(2) Effect According to the above configuration, during braking, as both the first and second friction pads wear out, a large relative displacement occurs between the first friction pad and the brake caliper, and this relative displacement The mechanism converts the pressure into a pressing force on the middle part of the warning sound generating piece, and this pressing force is transmitted to the free end of the warning sound generating piece that rubs against one side of the brake disc, so that each friction pad Even if the wear of the brake disc is small, the contact pressure of the warning sound generating piece against the side surface of the brake disc increases, resulting in a loud warning sound being emitted.

(3) Embodiment The sliding caliper type disc brake shown in Figs. 1 and 2 is used for automobiles, and a brake disc D fixed to a wheel rotates in the direction of arrow R when the vehicle moves forward. A bracket 1 fixed to the vehicle body is arranged adjacent to one side of the brake disc D, and first and second friction pads 2 1 , 2 2 having linings 2a facing each other on both sides of the brake disc D are attached to the bracket _{1 .} A back plate 2b is slidably supported in the axial direction of the brake disc D. Also, bracket 1
Both ends of a brake caliper C having first and second pinching arms 3 ₁ , 3 ₂ spanning both friction pads 2 ₁ , 2 ₂ are connected via a pair of sliding pins 4 , 4 . These sliding pins 4, 4 are arranged parallel to the axis of the brake disc D, so that the brake caliper C can slide in the axial direction of the brake disc D. A hydraulic cylinder 5 is formed in the first pinch arm ₃₁ of the brake caliper C, and a bottomed hollow piston 6 is slidably connected to the hydraulic cylinder 5.
The piston 6 is the back plate 2b of the first friction pad ₂₁ .
The second pinching arm 3 ₂ abuts against the back plate 2 b of the second friction pad 2 ₂ . 7 is a hydraulic conduit connection port of the hydraulic cylinder 5.

Lining 2 of the first and second friction pads 2 ₁ and 2 ₂
The first friction pad ₂₁ is provided with an alarm sound generating piece 8 that rubs against the side surface of the brake disc D when a wears beyond a certain value.

The alarm sound generating piece 8 is formed by bending a plate-like spring member into a substantially U-shape, and is connected to a base end 8a fixed to the back surface of the back plate 2b and the base end 8a. and an engaging portion 8b extending along the first pinching arm ₃₁ in a direction substantially perpendicular to the side surface of the brake disc D;
a straight portion 8c that extends in a direction substantially perpendicular to the side surface of the brake disc D and has a free end a protruding from the front surface of the back plate 2b to face one side surface of the brake disc D;
A bent portion 8d that connects the engaging portion 8b and the straight portion 8c.
It becomes more.

The engaging portion 8b includes an inclined portion b in the middle portion such that the flat portion on the side of the bent portion 8d is closer to the first pinching arm 3 ₁ than the flat portion on the side of the base end portion 8a. Further, the base end portion 8a is fixed to the back plate 2b by half-piercing the mounting hole 9 in the back plate 2b, fitting the protruding small shaft 10, and then caulking the small shaft 10. .

On the other hand, on the outer surface of the first pinching arm ₃₁ , there is a protruding portion 1 that constitutes the cam mechanism of the present invention together with the engaging portion 8b.
1 is formed. The protruding portion 11 is formed with a slope c that faces parallel to the slope portion b.
During braking, these slope portions b and c are the first,
When a relative displacement of a predetermined value or more occurs between the first friction pad ₂₁ and the brake caliper C due to wear of the linings 2a of the second friction pads ₂₁ and ₂₂ of a predetermined value or more, they engage with each other. It's becoming like that.

Next, the operation of this embodiment will be explained. When hydraulic pressure is applied to the hydraulic cylinder 5 from the brake master cylinder via a hydraulic conduit (not shown), the piston 6 moves forward due to the hydraulic pressure and the first friction pad 2
The back plate 2b of _{No. 1} is pressed to bring the lining 2a into pressure contact with one side of the brake disc D. Then, in response to this reaction, the brake caliper C slides via the sliding pins 4, 4 in the opposite direction to the forward movement of the piston 6, and is moved to the second friction pad ₂₂ via the second pinching arm _32.
The rear surface of the brake disc D is pressed to bring the lining 2a into pressure contact with the other side surface of the brake disc D. In this way, the friction force, that is, the braking force, can be applied to both sides of the brake disc D by the friction pads 2 ₁ and 2 ₂ .

During the above-mentioned braking, the first and second friction pads 2
If the linings 2a of ₁ and 2 ₂ have sufficient thickness as shown by the solid line in Figure 2, the alarm sound generating piece 8
The free end a is away from the side surface of the brake disc D.

However, as the linings 2a of both the first and second friction pads 2 ₁ and 2 ₂ wear out due to repeated operation of the brake over a long period of time, and the thickness of each of them decreases to a specified amount as shown by the chain line in FIG. First friction pad 2
The distance between the back plate 2b of ₁ and the brake disc D decreases, and the free end a of the alarm sound generating piece ₈ comes into contact with the brake disc _D. The distance increases and the protrusion 11
Since the slope c engages with the slope b of the engaging part 8b of the alarm sound generating piece 8, the pressing force of the slope c against the slope b causes the engaging part 8b to break away from the part connected to the base end 8a. bend and press the free end a further against the side of the brake disc D. In this way, a pressing force can be applied to the alarm sound generating piece 8 in accordance with the total amount of wear of both the first and second friction pads 2 ₁ and 2 ₂ . As a result, the free end a relative to the side surface of the brake disc D
contact pressure can be increased. Then, as the brake disc D rotates, the free end a rubs against the side surface of the brake disc D, so a loud warning sound is generated, thereby surely informing the operator that the thickness of the lining 2a is approaching its usable limit. Can be done.

C. Effect of the invention As described above, according to the invention, the alarm sound generating piece is formed into a substantially U-shape by an elastic plate, one end of which is fixed to the back plate of the first friction pad, and the other end is a free end. as opposed to one side of the brake disc,
Between the middle part of this alarm sound generating piece and the brake caliper, the alarm sound is generated when the first friction pad and the brake caliper undergo relative displacement due to wear of both the first and second friction pads exceeding a certain value. Since the cam mechanism is configured to press the middle part of the generating piece and slide its free end against one side of the brake disc, the pressing force corresponding to the total amount of wear of both the first and second friction pads generates an alarm sound. Even if there is little wear on each friction pad, it is possible to increase the contact pressure of the warning sound generation piece against the side of the brake disc, thereby generating a loud warning sound that can be heard. It can be made easier.

[Brief explanation of the drawing]

FIG. 1 is a front view of an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line of FIG. 1. C... Brake caliper, D... Brake disc, a... Free end, 1... Bracket, 2 ₁ ,
2 ₂ ...first and second friction pads, 2b...back plate,
3 ₁ , 3 ₂ ... first and second pinch arms, 6 ... piston, 8 ... alarm sound generating piece, 8b, 11 ... engaging portion and protruding portion constituting the cam mechanism.

Claims (1)

[Claims for Utility Model Registration] The first and second pinching arms of the brake caliper are arranged so as to straddle a brake disc and first and second friction pads facing each other on both sides thereof, and A piston capable of pressing the friction pad against one side of the brake disk is slidably provided on the first pinching arm, and a reaction of the piston causes the second pinching arm to press the second friction pad against the other side of the brake disk. A disc brake for a vehicle is provided with a brake caliper slidably mounted on a fixed bracket, and equipped with an alarm sound generation piece that rubs against a side surface of the brake disc when the friction pad wears beyond a certain value, An alarm sound generating piece is formed into a substantially U-shape by an elastic plate, one end of which is fixed to the back plate of the first friction pad, and the other end is set as a free end to face one side of the brake disc, thereby generating this alarm sound. Between the middle part of the piece and the brake caliper, the middle part of the warning sound generating piece is caused by the relative displacement of the first friction pad and the brake caliper due to wear of both the first and second friction pads exceeding a certain value. 1. A disc brake for a vehicle, comprising a cam mechanism that presses a part of the brake disc and slides its free end against one side of a brake disc.