JPH07280005A - Pad returning mechanism for disk brake - Google Patents

Abstract

PURPOSE:To realize a pad returning mechanism showing an effect on the prevention of the dragging of a disk brake for a long term CONSTITUTION:A liner 3 installed between a torque member 1 and the ear part 2b of a pad 2 is made slideable in the axial direction of a disk, and an elastic body 4 is disposed between the part of receiving the reactive force of the liner and the ear part 2b to make the elastic deformation force of the elastic body 4 and the slide resistance of the pad 2 smaller than the slide resistance of the liner 3. Since more force than the slide resistance of the liner 3 is not applied to the elastic body 4 compressed at the time of braking and pushed back at the time of decompression, the loss and fatigue of the elastic body 4 are not produced, so that a pad return effect may be maintained for a long term.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk brake drag preventing device (herein referred to as a pad returning mechanism) mounted on an automobile or the like.

[0002]

2. Description of the Related Art In a disc brake in which a pad to be slidably contacted with a disc is slidably supported by a torque member (fixing member) in the disc axial direction, a sliding surface is protected and rusted between a torque receiving member and a pad sliding surface. To prevent this, a liner made of stainless steel or copper-based metal is attached.

A disc brake having this liner is
In particular, since the sliding resistance of the pad increases, the pad does not return easily when depressurized (releases the braking), and the disk drags due to the pad during normal running without braking, which deteriorates fuel efficiency.

Therefore, in Japanese Utility Model Publication No. 59-139638,
A rubber elastic body is interposed between the torque member and the sliding surface of the pad, and the elastic force of the rubber elastic body that is elastically restored at the time of depressurization is used by elastically deforming the rubber elastic body by pulling it with the pad during brake operation. A device for pulling back the pad by an appropriate amount is proposed.

[0005]

In the drag prevention device disclosed in the above publication, the strong tangential force applied to the pad at the time of braking is applied to the rubber elastic body as it is, so that the rubber elastic body is easily worn and the drag prevention effect is reduced. Long-term maintenance is difficult.

[0006] Therefore, an object of the present invention is to make the return function of the pad exerted for a long period of time.

[0007]

In order to solve the above problems, according to the present invention, a liner mounted between a torque member and a sliding surface of a pad is attached to a pad, and a force in the disc axial direction is applied to the liner. A structure is provided in which an elastic deformation portion that receives and deforms is provided, and one end side of the elastic deformation portion is brought into contact with the guide groove of the torque member in a state having a sliding resistance larger than the force that deforms the elastic deformation portion, or the liner is torqued. A predetermined sliding resistance is applied to the member to attach it to the pad, and an elastic support portion is provided between the liner and the front portion of the pad in the pressing direction. The elastic deformation force of the elastic support portion and the pad on the liner are provided. The sliding resistance of the liner was set to be smaller than the sliding resistance of the liner, and this was used as the pad return mechanism.

[0008]

[Operation] When the brake is applied, the pad is pushed by the actuator such as the brake piston to move to the disc side up to the place where it hits the disc. At this time, since the liner provided with the elastically deforming portion moves together with the pad while one end side of the elastically deforming portion is caught in the guide groove, the elastically deforming portion is deformed by applying a force in the disc axial direction, The pad is pushed back at the time of decompression by the elastic recovery force of that portion. Further, when the pad wears, the portion in contact with the guide groove receives a force exceeding the contact resistance and slides by an amount corresponding to the wear amount, whereby the push-back amount of the pad is always kept substantially constant.

On the other hand, in the mechanism in which the elastic support portion is provided between the liner and the pad, the liner having a larger sliding resistance than the pad when the pad is pressed against the disk is held by the torque member. Therefore, only the pad moves, so that the elastic support portion is pressed by the pad and elastically deforms, and the elastic restoring force generated by this deformation pushes the pad back during decompression.

Further, the liner slides when the force applied to the elastic support portion exceeds the sliding resistance with the torque member, and therefore the upper limit of the force applied to the elastic support portion is always equal to the sliding resistance of the liner. It can be suppressed to the same level, and even an elastic support portion made of rubber or the like can be protected.

Since the sliding of the liner stops at the balance point between the sliding resistance and the pressing force acting on the elastic supporting portion, even if the liner slides, the elastic deformation of the elastic supporting portion is completely restored. However, the returning force of the pad is surely generated each time the vehicle is braked, and the returning amount of the pad is always kept almost constant regardless of the wear amount of the pad.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an example of the pad returning mechanism of the present invention. Reference numeral 1 denotes a torque member, and a caliper (not shown) and a pad 2 are supported by the torque member so as to be slidable in the disc axial direction. The torque member 1 is provided with guide grooves 1a for engaging the ears 2b provided on both sides of the pad back plate 2a so as to face each other, and there are a total of four locations on the inner and outer disc entry and exit sides. (The figure shows only one of them.) Each liner 3 has a proper sliding resistance in the groove 1a provided in the longitudinal direction of the groove (axial direction of the disk).
It is attached so that it can slide on.

The liner 3 has a U-shaped ear receiving portion 3a which is placed along the three surfaces of the groove 1a, and a skirt portion 3b which extends along the torque receiving surface of the torque member. It has a structure in which a locking piece 3c for preventing the pad 2 from coming off from the front and the back and a reaction force receiving portion 3d are continuously provided.

The reaction force receiving portion 3d is located on the front side in the pad pressing direction of the ear portion 2b and has an elastic body 4 such as rubber on its inner surface.
Is attached, and the ear portion 2b of the pad is inserted between the elastic body 4 and the locking piece 3c.

The sliding resistance of the pad 2 against the liner 3 and the elastic deformation force of the elastic body 4 are smaller than the sliding resistance of the liner 3 against the torque member 1. Therefore, when the pad 2 is pressurized, The elastic body 4 is compressed and only the pad 2 moves as shown by the chain line in FIG. 1B, and the pad 2 is pushed back by the restoring force of the elastic body 4 at the time of depressurization by an amount corresponding to the movement amount.

When the pad is returned, the liner 3 is retained by the torque member 1 due to the sliding resistance and receives a reaction force, but when the pad is worn and a force exceeding the sliding resistance acts on the elastic body 4, the pad wear amount is increased. Sliding to the disk side for a considerable amount.
Therefore, the stroke of the brake actuator and the return stroke of the pad by the elastic body 4 are always constant, and the pedal feeling is not deteriorated and the amount of brake fluid consumed does not fluctuate.

FIG. 2 shows an example of a method of adding sliding resistance to the liner 3. The liner 3 in FIG. 1 has a proper tightening margin with respect to the groove 1b to generate sliding resistance. However, as shown in FIG. 2, the liner 3 is provided with an elastic claw 3e and the claw is formed in the groove 1b.
The structure in which the inner surface is pressed against can also provide the necessary sliding resistance.

The elastic claw 3e may be provided at a position contacting any of the three groove surfaces.

The elastic body 4 may also be an elastic claw or the like integrated with the liner 3.

In FIG. 3, the liner 3 attached to the pad 2 is provided with an elastically deformable portion 5, and one end of this elastically deformable portion is provided with the guide groove 1
It is pressed against a so as to generate an appropriate sliding resistance. In this structure, one end of the elastically deformable portion 5 is hooked on the groove surface of the guide groove 1a and retained at that position, so that when the pad slides, the elastically deformable portion 5 is deformed and a pad restoring force is generated.

Further, when the pad wears, the force applied to the elastically deforming portion 5 exceeds the sliding resistance of the contact portion with the guide groove 1a, and one end of the elastically deforming portion slides toward the disk side by the amount corresponding to the pad wear amount. Keep the return stroke of. The mechanism of FIG. 3 has a basic configuration, and the mechanism of FIG.
It can be said that the elastically deforming portion 5 is arranged. Note that the elastically deforming portion 5 may be arranged either behind or in the pressing direction of the pad, as shown in FIGS. 3 (a) and 3 (b).

[0022]

As described above, according to the present invention, the liner mounted between the torque member and the sliding surface of the pad is movably supported, and the liner that moves following the wear of the pad is used as a reaction force to receive the liner. Force of elastically deforming part provided on the base or elastic supporting part provided between the liner and pad (elastic restoring force at depressurization)
Since the pad is pushed back by, no force exceeding the sliding resistance of the liner is applied to the elastically deforming part and elastic supporting part, and wear and fatigue of that part are prevented and the drag prevention effect can be maintained for a long time. .

[Brief description of drawings]

FIG. 1A is an exploded perspective view showing an example of a pad returning mechanism of the present invention. FIG. 1B is a partially cutaway plan view of the same as above.

FIG. 2A is a perspective view showing a modified example of the liner. FIG. 2B is a partially cutaway plan view of the pad returning mechanism using the liner.

FIG. 3A is a diagram showing an example of a mechanism in which a liner is provided with an elastically deforming portion for returning the pad. FIG. 3B is a diagram showing a mechanism in which the elastically deforming portion is installed on the opposite side of FIG. 3A. Figure

[Explanation of symbols]

 1 torque member 1a guide groove 2 pad 2a back plate 2b ear 3 liner 3d reaction force receiving part 4 elastic body 5 elasticity

Claims (2)

[Claims] 1. A disc brake in which a pad, which is brought into sliding contact with a disc, is slidably supported by a torque member in the disc axial direction. A liner mounted between the torque member and the sliding surface of the pad is attached to the pad. , An elastically deformable portion that is deformed by receiving a force in the axial direction of the disk is provided, and one end side of this elastically deformable portion is brought into contact with the guide groove of the torque member so as to have a sliding resistance larger than the force for deforming the elastically deformable portion. Pad brake mechanism for disc brake. 2. A disc brake in which a pad, which is brought into sliding contact with a disc, is slidably supported by a torque member in the disc axial direction. A liner mounted between the torque member and the pad sliding surface has a predetermined sliding resistance with respect to the torque member. The pad is attached to the pad, and an elastic support is provided between the liner and the front part of the pad in the pressing direction. The elastic deformation force of the elastic support and the sliding resistance of the pad on the liner are slid on the liner. A disc brake pad return mechanism configured to be smaller than the dynamic resistance.