JP2001304310A - Disc brake - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate nonconformities such as unstable performance and squeal generated, when braking due to the fluctuation of the contact point of a pad with a torque receiving face caused by dispersion in perpendicularity between the inner peripheral surface and a pad side face and dispersion in perpendicularity between a support face and the torque receiving face in a disc brake, where the side face of the pad abuts on the torque receiving face in the state of the inner peripheral surface of the pad being pressed to the support face of high rigidity by a spring. SOLUTION: A thinned part 8, absorbing an allowable machining error in manufacture and separating the pad side face 2b on the disc inner peripheral side with respect to a pressing center O from the torque receiving face 7, is provided between the pad 2 and the torque-receiving face 7, so that the pad is always constrained at three points A, B, C.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disc brake for stabilizing performance and suppressing so-called noise (noise sound) during braking.

[0002]

2. Description of the Related Art There is a known disk brake in which a friction pad (hereinafter, simply referred to as a pad) is supported by a pad pin which is suspended between an inner portion and an outer portion of a caliper. In this type of disc brake, the pad is suspended through the pad pin in the pin hole provided in the pad, so it is not necessary to fit both sides of the pad to the caliper unevenly,
The shape of the torque receiving portion is simplified, so that the caliper casting can be facilitated, the processing cost by reducing the cutting allowance, the processing time can be reduced, and the tool cost can be reduced by simplifying the shape of the cutting tool. Another advantage is that the pad can be replaced simply by removing the pad pin.

On the other hand, since the pad is supported by the torque receiving surface provided on the caliper and the low-rigidity pad pin at the time of braking, the restraint of the pad tends to be unstable due to the bending of the pad pin.

On the other hand, as shown in FIG. 4, a support surface 6 on the inner periphery of the pad is provided on the disk entrance side and the disk exit side of the caliper 1, and the pad 2 is provided on the support surface 6 for preventing rattle noise. The structure of pressing with the spring 5 is such that the pad 2
It is restrained at three points of the support surface 6 and the torque receiving surface 7 having high rigidity formed on the caliper, and the stability of the restraint is excellent. In this structure, the pin 3 laid between the inner portion and the outer portion of the caliper 1 is passed through a pin hole 9 provided in the pad in order to prevent the pad 2 from coming off. And the pin 3 does not directly restrain the pad.

[0005]

If the restraint of the pad is unstable, the pad moves at the beginning of braking, which triggers the pad to vibrate and squeal. Therefore, as compared with the structure in which the movement of the pad is restricted by the pad pin, FIG.
The structure is easier to prevent squeal.

However, the brake having the structure shown in FIG. 4 may also make a squeal. When the cause was investigated, the contact point of the pad with the torque receiving surface fluctuated due to variations in the processing accuracy of the pad and caliper, and when the contact point was biased toward the center of the disk, the pad restraint became unstable and squealed. Was found to occur.

FIG. 5A shows an example in which the inner peripheral surface 2a and the side surface 2b of the pad 2 have a bad perpendicularity, and the pad 2 hits the torque receiving surface 7 on the outer peripheral side of the disk (upper side in the figure). Is shown. As shown in FIG. 5B, the same situation occurs when the perpendicularity between the support surface 6 on the caliper side and the torque receiving surface 7 is bad.

Further, as shown in FIGS. 5 (c) and 5 (d),
Since the perpendicularity between the inner peripheral surface 2a and the side surface 2b of the pad and the perpendicularity between the support surface 6 and the torque receiving surface 7 are poor, the pad 2 may hit the torque receiving surface 7 on the inner peripheral side of the disk.

As described above, when the position of the contact point of the pad fluctuates due to the processing accuracy, the braking performance varies. Further, in the cases of FIGS. 5C and 5D, a rotational moment f is generated in the pad 2 by the braking reaction force generated at the contact point P, and this force causes the disk reciprocating side (the right side in the figure) of the pad to move. Support surface 6
And the restraint of the pad becomes unstable. The squealing occurred in the structure of FIG. 4 in the cases (c) and (d) of FIG.

In order to eliminate the fluctuation of the contact point of the pad due to the processing error, the processing accuracy (the perpendicularity between the inner peripheral surface and the side surface of the pad and the perpendicularity between the support surface of the caliper and the torque receiving surface) may be increased. This method increases processing costs. Also,
It is very difficult to completely match the two angles even if the processing accuracy is increased.

Therefore, an object of the present invention is to make it possible to eliminate the above-mentioned disadvantages by a simple process.

[0012]

In order to solve the above-mentioned problems, in the present invention, a caliper or a torque member is provided with a torque receiving surface and a supporting surface for supporting the inner periphery of the pad substantially at right angles to the torque receiving surface. Provided, the disk inflow side,
A friction pad is pressed against each support surface on the circulation side with a spring, and a side surface of the friction pad is brought into contact with the torque receiving surface to receive a braking torque. In addition, there is provided a slack portion that absorbs a permissible processing error in manufacturing and separates the pad side surface on the inner peripheral side of the disc from the center of pressing by the brake piston from the torque receiving surface during braking.

The above-mentioned slack portion may be formed by narrowing the pad width on the inner peripheral side of the disk, or may be formed by denting the inner peripheral side of the disk on the torque receiving surface. The former method is easier to manufacture the brake than the latter method. However,
In both cases, there is no difference in the effects of stabilizing performance and preventing squeal.

[0014]

When the above-mentioned slack portion is provided, the pad is always pressed by the brake piston even if the perpendicularity between the inner peripheral surface and the side surface of the pad and the perpendicularity between the support surface on the inner peripheral surface of the pad and the torque receiving surface are insufficient. It hits the torque receiving surface on the outer peripheral side of the disc from the center. Therefore, the rotational moment generated on the pad by the braking reaction force is opposite to the direction shown in FIG. 5C, and the pad is prevented from floating from the support surface on the disk reciprocating side.
On the disc eject side, a force acts on the pad to lift it from the support surface on the disc eject side, but on the disc eject side, the force pressing the pad against the torque receiving surface and the force on the disc center Since the pressing force acts strongly, the floating of the pad from the disk feeding side support surface is also reliably prevented. As a result, the pad is stably restrained at three points A, B, and C shown in FIG. 2, and no squealing occurs.

Further, since the pad contact point does not fluctuate beyond the pressing center, the braking performance is stabilized.

[0016]

1 and 2 show an embodiment of a disc brake according to the present invention.

An exemplary brake is of the piston opposing type,
Two pads 2 disposed opposite each other with the caliper 1 and the disk D interposed therebetween, a pin 3 passing through each pad 2, a brake piston 4 pressing each pad to slide against the disk, and a spring 5 for preventing rattle noise have.

The caliper 1 is provided with a support surface 6 for supporting the inner periphery of the pad 2 slidably in the disk axial direction on the reciprocating side and the reciprocating side of the disk D, and a torque receiving surface 7 arranged oppositely. Each of the torque receiving surfaces 7 on the disk inlet side (right side in FIG. 2) and the outlet side is substantially perpendicular to the support surface 6, but there is a certain error in the perpendicularity of the surfaces 6, 7 And so on, so that the cutting of such surfaces does not become difficult.

As shown in FIG. 2, the pad 2 has an inner peripheral surface 2.
a is a straight surface, and a portion of the side surface 2b on the outer peripheral side of the disk is substantially perpendicular to the inner peripheral surface 2a. Further, the present invention is characterized in that the inner peripheral portion of the side surface 2b is inclined by θ in a direction in which the pad width becomes narrower on the inner peripheral side of the disk from the outer peripheral side of the center O of pressing by the brake piston 4 with the torque receiving surface 7. The slack portion 8 is generated.

The value of θ is determined in consideration of the allowable machining error between the caliper and the pad. Even when the machining error is maximized, the pad separates from the torque receiving surface 7 during braking on the inner circumferential side of the disk from the pressing center. It is set as follows.

The pin 3 extends between the inner portion 1a and the outer portion 1b of the caliper 1, and the pin 3 is loosely fitted into a pin hole 9 provided in the pad 2 to prevent the pad 2 from coming off the caliper 1. The pin hole 9 and the inner peripheral surface 2a and side surface 2b of the pad are formed on the back plate of the pad.

The brake piston 4 is inserted into a cylinder (not shown) provided on the caliper 1, and is propelled by hydraulic pressure introduced into the cylinder.

The spring 5 is locked inside the pin 3 to receive the reaction force with the pin 3 and apply a downward force to the pair of pads 2 with respect to the disk reciprocating side and the reciprocating side by the wings at both ends. I have to.

FIG. 3 shows an example in which the inner peripheral side of the torque receiving surface 7 is dented to form the recessed portion 10.

2 and 3, the pad 2 is restrained by the caliper 1 at three points A, B and C during braking. The contact point A with the torque receiving surface 7 is always on the disk outer peripheral side with respect to the pressing center by the brake piston 4, and therefore, A
The rotational moment f generated on the pad 2 by the braking reaction force of the point is
As shown in the direction of the arrow in the figure, the pad 2 is strongly pressed against the support surface 6 also on the disk reciprocating side.

In the illustrated brake, the support surface 6 and the torque receiving surface 7 are provided on the caliper. However, these surfaces are provided on a torque member separate from the caliper, and the disc is used to restrain the pads by the torque member. The invention can be applied to a brake.

[0027]

As described above, in the disc brake of the present invention, the slack portion for separating the pad from the torque receiving surface is provided between the pad and the torque receiving surface on the inner peripheral side of the disk with respect to the center of pressing by the brake piston. An inherent problem found in the type of brake provided with a highly rigid support surface to support the inner periphery of the pad, namely, the right angle of the pad, the pad contact point due to the poor right angle between the support surface of the inner surface of the pad and the torque receiving surface. The pad is stably restrained at three points during braking because the reaction force during braking eliminates fluctuations in the pad and generates a rotational moment in the direction of pressing the disk entry side of the pad against the support surface. The squeal is effectively prevented.

Further, since the fluctuation of the pad contact point beyond the pressing center does not occur, the braking performance is stabilized, and the reliability of the disc brake is further increased.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of a disc brake according to the present invention.

FIG. 2 is an enlarged cross-sectional view taken along a line II-II in FIG.

FIG. 3 is a cross-sectional view of another embodiment.

FIG. 4 is a sectional view of a disc brake to be improved.

FIG. 5 is an exaggerated view showing a state of change of a pad contact point due to a processing error.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Caliper 2 Pad 2a Inner peripheral surface 2b Side surface 3 Pin 4 Brake piston 5 Spring 6 Support surface 7 Torque receiving surface 8 Slack portion 9 Pin hole

Claims (3)

[Claims] A caliper or a torque member is provided with a torque receiving surface and a supporting surface for supporting the inner periphery of the pad substantially at right angles to the torque receiving surface. In a disc brake receiving a braking torque by pressing a pad with a spring and bringing a side surface of the friction pad into contact with the torque receiving surface, a disc is disposed between the friction pad and the torque receiving surface more than a pressing center by a brake piston. A disc brake having a sunk portion for separating an inner pad side surface from a torque receiving surface during braking. 2. The disk brake according to claim 1, wherein the slack portion is formed by reducing a pad width on an inner peripheral side of the disk. 3. The disc brake according to claim 1, wherein the slim portion is formed by denting the inner peripheral side of the torque receiving surface of the disc.