Hitachi Automotive Systems, Ltd.

Hitachi Automotive Sysetms, Ltd.

Nobuhiro Wakabayashi

Shigeru Hayashi

Satoru Tsurumi

Shinji Suzuki

Yohei Araki

Xuesheng Zhang

Hironobu Yukumi

A return spring () made of a metal plate, for biasing a friction pad () in a return direction of separating away from a disc () is arranged between the friction pad () and a mounting member (). The return spring () includes a fixed portion (), which is on a base end side fixed to an ear portion (B) of a back plate () of the friction pad (). Then, an abutment portion (), which is on a distal end side of the return spring (), is elastically brought into abutment on an abutment plate portion (D) of a pad spring (), which is on the mounting member () side at a position on an outer side in a disc radial direction relative to the fixed portion ().

Disc brake

A return spring is provided between a friction pad and a mount member. The return spring biases the friction pad in a return direction for separating the friction pad from the disk, and is made of a metallic plate. The return spring includes a fixation portion on a proximal end side thereof, and the fixation portion is fixed to an ear portion of a back plate of the friction pad. The return spring includes an abutment portion, and the abutment portion is in elastic abutment with an abutment plate portion of a pad spring, which corresponds to a mount member side, on an outer side in a disk radial direction relative to the fixation portion. The pad spring includes a guide portion extending in a disk axial direction and supporting a side surface of an intermediate portion of the return spring.

Disk brake

A shim plate relatively movably attached with a friction pad in a rotational direction of a disc is disposed between the friction pad and a reaction section of a caliper, a plurality of claw sections formed to extend in a radial direction of the disc at a position deviated in the rotational direction of the disc with respect to a center of pistons are formed at the reaction section, and movement restriction portions that can abut the intermediate claw section disposed at the middle of the claw sections of the reaction section are formed at a surface of the shim plate opposite to the reaction section in the radial direction of the disc.

A shim plate is provided at the rear side of a friction pad to abut annular contact parts of pistons. The shim plate is provided with first and second one-side cut portions and at a position corresponding to the annular contact part of a disk rotational entrance-side piston, for example, so that the area of contact between the shim plate and the annular contact part is larger at the disk rotational exit side than at the disk rotational entrance side. The first and second one-side cut portions and have four contact ends at which the peripheries of the cut portions and the annular contact part intersect each other. At least two of the four contact ends are provided on the disk rotational entrance side with respect to the diametrical center of the piston.

Provided is a disc brake capable of preventing large positional shift of a position of abutment of a return spring against a mounting member, which occurs with wear of a friction pad and the like. The return spring for biasing the friction pad in a direction away from a disc includes a fixed portion on one side, which is fixedly mounted to the friction pad, an extending portion extending from the fixed portion in an axial direction of the disc and in a direction away from the friction pad, a turned-back portion formed by turning back a distal end side of the extending portion toward the mounting member, and an abutting portion provided on a distal end side of the turned-back portion so as to be elastically brought into abutment against a side of the mounting member. A portion (bent portion) of the turned-back portion, which is formed by bending the turned-back portion at the middle thereof, is located at a position separated farther away from the fixed portion than the abutting portion in a disc rotating direction.

Growing community of inventors

Minami-Alps, Japan

Nobuhiro Wakabayashi