JPH0645068Y2 - Friction pad return structure for vehicle disc brakes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a vehicle disc brake that performs a braking action by pinching a disc rotor with a pair of friction pads. The present invention relates to a friction pad returning structure for a vehicle disc brake that forcibly pulls back from a disc rotor to prevent drag of the friction pad.

[Conventional technology]

In this type of disc brake in which a disc rotor that rotates together with wheels is pressed by a pair of friction pads to perform braking action, the friction pads when releasing braking do not sufficiently separate from the disc rotor, Since it is dragged by the rotor, uneven wear of the lining or drag noise is generated, or unnecessary load is applied to the drive system device, which may cause problems such as reduced fuel consumption. For example, Japanese Utility Model Publication No. 61-12419. As shown in the official gazette, there is one in which both friction pads are elastically forced to return in the separating direction.

In this technique, a pair of friction pads arranged opposite to each other on the disc rotor are slidably attached to a hanger pin arranged in the disc axial direction, and the coil inner diameter is larger than the diameter of the hanger pin on the hanger pin. A coil spring in which a small diameter part and a large diameter part where the coil inner diameter is larger than the diameter of the hanger pin are formed continuously is mounted by fitting the small diameter part with the disk rotor side, and the free length and close contact length of the large diameter part Is selected to be equal to the desired brake clearance, while the frictional force on the hanger pin in the small diameter part is selected to be larger than the close contact load in the large diameter part and smaller than the driving force of the piston inserted in the caliper cylinder hole. It is characterized by having done.

With such a configuration, the amount of movement of the friction pad from when the friction pad starts to compress the large diameter portion during braking until the large diameter portion comes into close contact is always set accurately, and if the large diameter portion comes into close contact, The small diameter part forcibly moves on the hanger pin via the closely attached large diameter part to compensate for the increase in brake clearance due to wear of the lining, and when releasing the braking,
The friction pad is pushed back by a distance equal to a predetermined brake clearance.

[Problems to be solved by the device]

However, the above-mentioned coil spring has a special shape having a large diameter portion and a small diameter portion, and since each of the large and small diameter portions is separately formed as a custom-made product having an individual set load, high cost is avoided. Moreover, when replacing the friction pad, the coil spring must be detached from the hanger pin each time, and the work is complicated and troublesome.

Further, since the coil spring is required to be attached to the hanger pin, it cannot be applied to a caliper having no hanger pin.

In order to achieve the above-mentioned object, the present invention uses the torque receiving portion of the supporting arm provided in this type of disc brake and the retainer attached to the torque receiving portion, and there is no problem in replacing the friction pad. Another object of the present invention is to provide, at low cost, a friction pad returning structure which has a simple structure and can be implemented with or without a hanger pin.

[Means for Solving the Problems]

In order to achieve the above object, the friction pad returning structure of the present invention includes a bracket fixed to a vehicle body, a support arm extending over the disk rotor, and a torque formed by sandwiching the disk rotor on the support arm. A retainer is attached to the receiving portion, and ear pieces are projectingly provided on both sides of the back plate of the friction pad which is arranged to face each other on both sides of the disc rotor, and the ear pieces are supported by the torque receiving portion via the retainer. In a vehicle disc brake that suspends the friction pad so as to be movable in the disc axial direction, a claw piece is projectingly provided on an outer peripheral portion of the disc rotor of the retainer, and the claw portion holds a coil portion of a coil spring, Both ends of the coil spring,
It is characterized in that the coil springs are contracted by being brought into contact with the inner surfaces of the ear pieces of the both friction pads.

[Action]

An existing compression coil spring is used as the above-mentioned coil spring, and it is assembled in advance as a unit to the retainer before being mounted on the torque receiving portion. The unitized coil spring is attached to the torque receiving portion on the disc feeding side of the caliper, or to the torque receiving portion on both the disc feeding side and the feeding side of the caliper. Since the coil spring attached to the torque receiving portion does not engage with the friction pad or the hanger pin, the friction pad can be replaced regardless of the coil spring.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

The disc brake 1 is a front brake that brakes the front wheels of a motorcycle, and a bracket 2 fixed to the vehicle body is provided with a support arm 2a extending in the disc axial direction across the disc rotor 3 and supporting the same. A floating caliper 4 is supported on the arm 2a by a cantilever on the side where the disk extends.

The caliper 4 has a structure in which a working portion 4a to which a pressurized liquid is supplied and a reaction portion 4b facing the working portion 4a with the disc rotor 3 sandwiched therebetween are connected by a bridge portion 4c straddling the outer periphery of the disc rotor 3. ing. A mounting arm 4e having an insertion hole 4d is provided in the action portion 4a, and the caliper 4 is a support arm.
The slide pin 5 projecting from 2a is inserted into the insertion hole 4d, and is attached so as to be movable in the disc axial direction.

Between the action portion 4a and the reaction portion 4b, a pair of friction pads 8, 8 having a backing plate 6 and a lining 7 attached thereto are arranged to face each other with the disc rotor 3 interposed therebetween. This friction pad 8,8
Each back plate 6 inserts the hanger pins 9 and 9 through the through holes 6b and 6b of the hanging pieces 6a and 6a, and the ear pieces 6c protruding to the disc feeding side of the caliper 4 from the supporting arm 2a. While being hung from the torque receiving portion 2b via the retainer 10, the elastic force of the pad spring 11 compressed between the hanging pieces 6a, 6a and the inner wall of the bridge portion 4c causes play in the disk inner diameter direction. It is held without any attachment.

When pressure fluid is supplied to the action portion 4a from a known hydraulic master cylinder (not shown), a piston (not shown) inserted in the cylinder hole of the action portion 4a advances, and a friction pad on the action portion side. 8 is a disk rotor 3 that rotates in the direction of arrow A.
Press on one side. Next, the caliper 4 moves to the action portion 4a side by this reaction, and the reaction portion 4b presses the friction pad 8 on the reaction portion side against the other side surface of the disc rotor 3 to brake the disc rotor 3. During this braking, the braking torque generated on both friction pads 8 is the back plate 6
It is supported by the torque receiving portion 2b of the bracket 2 which engages with the ear piece 6c.

The torque receiving portion 2b is formed on the side of the caliper 4 of the support arm 2a toward the disc entry side, and is formed in a groove shape in the disc axial direction with the rotor groove 2c interposed therebetween. The retainer 10 mounted on the torque receiving portion 2b has locking pieces 10b, 10b for mounting extending in the support arm 2a direction on both sides of a U-shaped main body 10a, and a central portion of the main body 10a. A notch 10c for the disk rotor is formed, and a claw piece 10d is bent and formed in an L shape at the upper part of the notch 10c on the outer peripheral side of the disk rotor 3 when mounted. The main body 10a is fitted in the torque receiving portion 2b, and the locking pieces 10b, 10b are locked to both end surfaces of the support arm 2a to be mounted.

A coil spring 12 that is contracted between the friction pads 8 is attached to the claw piece 10d. This coil spring 12 elastically repulses both friction pads 8 and 8 in the separating direction at the time of non-braking to prevent the friction pads 8 and 8 from being dragged.
In the coil spring 12, the retainer 10 before being attached to the torque receiving portion 2b is provided with the intermediate portion of the coil portion 10 in advance.
When the retainer 10 is attached to the torque receiving portion 2b of the bracket 2, the both ends are abutted against the inner surfaces of the ear pads 6 and 6c of the friction pads 8 facing each other. Are arranged.

This embodiment is configured as described above, and when the above-mentioned braking operation is released, the caliper 4 moves to the reaction portion side, and the piston retracts into the cylinder hole, so that the friction pads 8, 8 Is biased in the separating direction, but in the present embodiment, as described above, the coil spring 12 is contracted between the ear pieces 6c, 6c supported by the torque receiving portion 2b, and both friction pads 8, 8 are provided. Is forced to be pushed back from the side surface of the disc rotor 3 by the elastic force of the coil spring 12, so that the friction pad 8
Is reliably prevented from dragging.

Since the coil spring 12 is mounted as a unit by using the retainer 10 mounted on the torque receiving portion 2b, a dedicated mounting is not necessary, and an off-the-shelf product that does not require a special shape can be used, which is inexpensive. Can be manufactured. Also,
Even if the friction pads 8 and 8 are removed from the disc brake 1 by replacement or maintenance, the coil spring 12 is retained by the retainer 10 as it is. Therefore, replacement of the friction pads 8 and maintenance work can be performed in a short time regardless of the coil spring 12. Can be done easily.

Further, in this embodiment, the coil spring 12 prevents the friction pads 8 and 8 from coming off from the notches 10c of the retainer 10 when the disc rotor 3 is detached for maintenance. make it easier.

Since the friction pad return structure of the present invention is mounted by using the torque receiving portion of most disc brakes for mounting the coil spring, in addition to the cantilever type caliper shown in the above embodiment, for example, A collet type caliper in which both the disc turning-in side and the turning-in side are supported by the supporting arm, that is, a pair of supporting arms are arranged on the disc turning-in and feeding-out side of the caliper, and the friction receiving portion of the supporting arm is provided with friction. It can also be applied to a type that does not have a hanger pin that suspends the ear pieces on both sides of the pad.

[Effect of device]

As described above, in the friction pad returning structure of the present invention, the retainer mounted on the torque receiving portion of the support arm has the claw piece protruding from the outer peripheral portion of the disk rotor, and the claw piece holds the coil portion of the coil spring. At the same time, both ends of the coil spring are brought into contact with the inner surfaces of the ear pieces of both friction pads, and the coil springs are contracted so that even if the friction pads are removed for replacement or maintenance, the coil springs are retained in the retainer. Since it remains held, it is not necessary to attach and detach the coil spring each time pad replacement or maintenance is performed, and these operations can be performed easily in a short time. Furthermore, since it has a simple structure, it can be manufactured at low cost, and since it uses the torque receiving portion that most disc brakes have, it can be carried out with or without a hanger pin, and is highly versatile.

[Brief description of drawings]

1 shows an embodiment in which the present invention is applied to a front disc brake of a motorcycle, FIG. 1 is an exploded perspective view of a friction pad, a retainer and a coil spring, FIG. 2 is a partially cutaway plan view of the disc brake, Fig. 3 shows III-I in Fig. 2.
It is a II sectional view. 1 ... Disc brake, 2 ... Bracket, 2a ... Support arm,
2b ... torque receiving portion, 3 ... disk rotor, 4 ... caliper, 5 ... slide pin, 6 ... back plate, 6a ... hanging piece, 6b ...
Through hole, 6c ... Ear piece, 7 ... Lining, 8 ... Friction pad, 9
… Hanger pin, 10… Retainer, 10a… Main body, 10c… Notch, 10d… Claw piece, 12… Coil spring

Claims (1)

[Scope of utility model registration request] 1. A bracket fixed to a vehicle body is provided with a support arm extending over the disk rotor, and a retainer is attached to a torque receiving portion formed by sandwiching the disk rotor on the support arm. Ear pieces project from both sides of the back plate of the friction pad oppositely disposed on both sides, and the ear pieces are supported by the torque receiving portion via the retainer so that the friction pad can move in the disc axial direction. In a suspended vehicle disc brake, a claw piece is provided so as to project from an outer peripheral portion of a disc rotor of the retainer, and a coil portion of a coil spring is held by the claw piece, and both ends of the coil spring are connected to the friction pads of the both friction pads. Abut the inner surface of the ear piece,
A friction pad return structure for a vehicle disc brake, characterized in that a coil spring is contracted.