JPH0526352Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a disc brake applied to vehicles such as four-wheeled vehicles and motorcycles, and in particular, the invention relates to a disc brake that is applied to vehicles such as four-wheeled vehicles and motorcycles. The present invention relates to a friction pad return structure that is pulled back from the side surface of a disc rotor when braking is not applied to prevent uneven wear of the lining due to the dragging of the disc rotor.

[Conventional technology]

For disc brakes, which perform braking by pinching a disc rotor that rotates together with the wheel between a pair of friction pads, the friction pads are not separated sufficiently from the disc rotor when the brake is released, and the lining of the friction pads is damaged. Being dragged by the disk rotor,
For example, since it may cause uneven wear, the generation of dragging noise, or unnecessary load is placed on the drive system, resulting in a decrease in fuel efficiency.
A friction pad return structure as shown in Japanese Patent No. 172175 has been proposed.

This technology extends the back plate of each friction pad that is placed facing the side surface of the disc rotor to the outer periphery of the disc rotor, and hangs a hanger pin that spans the outer periphery of the disc rotor over this extension. Both ends of the wound coil spring are extended in the direction of the rotation center of the disc rotor, and introduced into the radial groove of the disc rotor cut in the center of the lining of each friction pad, and the ends are inserted into the center of the groove. With this structure, when the brake is released, the friction pads are springed apart by the coil spring, and are forcibly pulled back from the disc rotor.

[The problem that the idea attempts to solve]

However, as the lining wears down and the friction pad moves toward the disc rotor,
The gap between the grooves in both linings narrows, compressing the coil spring, increasing the return load on the friction pad, and pushing the piston back more than necessary.
There is a problem in that so-called knockback occurs in the piston, increasing the loss stroke of the piston.

The present invention was developed against this background, and its purpose is to maintain a constant return load on the friction pads and to reduce the bias of the linings, regardless of the movement of the friction pads due to wear of the linings. An object of the present invention is to provide a friction pad return structure that prevents wear and increases in loss stroke of a piston.

[Means to solve the problem]

In order to achieve the above object, the present invention includes a bridge portion of a caliper that straddles the outer periphery of a disc rotor;
In a disc brake for a vehicle in which a pad spring that springs the friction pad toward the center of the disc is compressed between a back plate of friction pads arranged opposite to each other on both sides of the disc rotor, the back plate is located on the center side of the disc. In addition to increasing the weight of the disc, a spring receiving part is formed on the outer circumferential side of the disk on the back plate and projects in a direction opposite to the disk rotor, and the pad spring is brought into pressure contact with the spring receiving part.

As a structure for increasing the weight on the disk center side of the back plate, for example, the area of the back plate on the inner diameter side of the disk may be increased, the area on the outer diameter side of the disk may be decreased, or the area of the back plate on the inner diameter side of the disk may be increased. Examples include forming a protrusion or retrofitting a weight that has a larger mass than the back plate. In the case of a type with a hanging lug on the back plate, the lug may be shifted toward the center of the disc and used as a weight.

In addition, the pressing part of the pad spring that presses the ring receiving part should be long enough so that the pressing force is always applied over the distance that the friction pad moves toward the disc rotor and the lining reaches its wear limit. It is formed.

[Effect]

With this configuration, the pressing force of the pad spring acts as a moment on the friction pad to rotate it toward the disc rotor using the spring receiver as a fulcrum, but the weight corresponding to the spring receiver cancels this moment, resulting in , the center of gravity of the friction pad moves toward the side opposite to the disc rotor. This makes it easier for the friction pad to move toward the opposite side of the disc rotor, and when the brake is released,
By competing with the disc rotor, it is effectively separated from the side surface of the rotor.

Furthermore, since there is no biasing member such as a coil spring, the return load acting on the friction pad is always kept constant regardless of movement of the friction pad due to wear of the lining.

〔Example〕

Hereinafter, one embodiment of the present invention will be described based on the drawings.

The disc brake 1 has a caliper 3 disposed straddling the disc rotor 2.
The caliper is a floating type that is movably supported in the disk axial direction by a bracket 4 placed on one side.
The caliper 3 connects an action part 3a disposed on the same side as the bracket 4 and a reaction part 3b disposed opposite the action part 3a with the disc rotor 2 in between, straddling the outer periphery of the disc rotor 2. It consists of a bridge part 3c.

The action part 3a has attachment arms 3 that protrude on both sides.
Sliding pins 5 are fixed to d and 3d with bolts 6, respectively, and a tip-shaped piston 7 is inserted into a cylinder hole 3e that is opened on the disk rotor 2 side.

Further, a pair of support arms 4a, 4a are provided on the outer periphery of the disc rotor 2 and are arranged on both sides of the bridge portion 3c of the caliper 3. Each of the sliding pins 5 is inserted into the pin hole 4b, and the operating portion 3
The a side is supported in a cantilevered manner.

The supporting arms 4a, 4a are provided with locking step portions 4c, 4c in the disk axial direction on the opposing inner sides, dividing the central portion, and the locking step portions 4c, 4c
A pair of friction pads 8, 8 disposed on both sides of the disc rotor 2 hold the lug pieces 9a, 9a of the back plate 9, and connect both back plates 9, 9 to the bridge portion 3.
The pad spring 10, which is compressed between the disc and the disc, causes the disc to be ejected in the direction of the center of the disc without any deflection.

A hydraulic pressure chamber 11 is defined at the bottom of the cylinder hole 3e by inserting the piston 7, and the hydraulic pressure chamber 1
1, when pressure fluid is supplied from a known hydraulic master cylinder (not shown), the piston 7 moves into the cylinder hole 3.
e forward to press one friction pad 8 against one side of the disc rotor 2, and then this reaction moves the caliper 3 toward the bracket 4, and the reaction part 3b pushes the other friction pad 8 against the disc rotor 2. A braking action is performed by pressing against the other side of 2.

The friction pad 8 is constructed by joining the back plate 9, which is suspended from the support arm 4a, and a lining 12, which is pressed against the disc rotor 2. The back plate 9 has the above-mentioned ears 9a, 9a near the center of the disk on both sides (lower side in FIG. 3), and has the above-mentioned ears 9a, 9a on the upper side.
It has two spring receiving parts 9b, 9b formed by punching out on the side opposite to the disc rotor, and a pad spring 1 is disposed on the upper surface of the spring receiving parts 9b, 9b, straddling the disc rotor 2.
0 pressure piece 10a is brought into pressure contact.

The ear pieces 9a, 9a also serve as weights to increase the weight of the disk center side of the back plate 9, and are applied to the friction pad 8 by the pressure of the pad spring 10, using the spring receiving portion 9b as a fulcrum. A moment is exerted to rotate the friction pad 8 toward the disk rotor 2, but the ears 9a, 9a act as weights to cancel this moment, and as a result, the center of gravity of the friction pad 8 moves toward the side opposite to the disk rotor.

This makes it easier for the friction pad 8 to move toward the side opposite to the disc rotor, and when the brake is released, it is easily separated from the side surface of the rotor 2 due to the competition with the disc rotor 2, effectively reducing uneven wear on the lining 12. can be prevented. The weight of the ear pieces 9a, 9a is set so as to balance and offset the above moment.

Furthermore, since a biasing means such as a conventional coil spring is not used, even if the friction pad 8 moves toward the disc rotor 2 due to wear of the lining 12, the return load on the friction pad 8 does not change. , prevents loss of stroke of the piston 7 due to knockback.

In the above embodiment, the lug of the back plate also serves as a weight, but in the present invention, the weight of the back plate on the disk center side is increased to correspond to the moment generated by the pressure of the pad spring. For example, the area of the back plate on the disk center side may be increased or the area of the disk outer diameter side may be decreased, or a protrusion may be formed on the back plate on the disk center side, or It is also possible to use other structures such as retrofitting a weight with a large mass.

Further, the spring receiving portion pressed by the pad spring may be formed by bending the upper part of the back plate toward the side opposite to the disc rotor.

[Effect of idea]

As described above, the present invention increases the weight of the back plate on the disk center side, and also forms a spring receiving part protruding in the direction opposite to the disk rotor on the outer peripheral side of the disk, and the spring receiving part is provided with the above-mentioned parts. Since the spring is pressed against the brake, when not braking,
To effectively prevent uneven wear of a lining by easily separating a friction pad from a disc rotor.

In addition, since it does not have a biasing member such as a coil spring, even if the friction pad moves toward the disc rotor, the return load on the friction pad can always be kept constant, eliminating loss stroke of the piston. The number of parts and assembly man-hours can be reduced.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which FIG. 1 is a cross-sectional view taken from FIG. 2, FIG. 2 is a partially sectional plan view of a disc brake, and FIG. 3 is a cross-sectional view taken from FIG. 2. 1... Disc brake, 2... Disc rotor, 3... Caliper, 4... Bracket, 8...
Friction pad, 9...Back plate, 9a...Ear piece that also serves as a weight, 9b...Spring receiver, 10...
Padded spring, 10a... Pressing piece, 12...
lining.

Claims (1)

[Scope of utility model registration request] A vehicle with a pad spring that springs the friction pads toward the center of the disk between the bridge part of the caliper that straddles the outer periphery of the disk rotor and the back plate of the friction pads that are placed facing each other on both sides of the disk rotor. In this disc brake, the weight of the back plate on the side of the center of the disc is increased, and a spring receiving part that protrudes in a direction opposite to the disc rotor is formed on the outer peripheral side of the disc of the back plate, and the pad spring is attached to the spring receiving part. A friction pad return structure for a vehicle disc brake, characterized in that the pads are brought into pressure contact with each other.