Patent ID: 9377070
Filing Date: 2016-06-28
CPC Classification: F16D

Claim Text:
1. A vehicle disc brake, comprising: a caliper bracket to be fixed to a vehicle body, the caliper bracket including a pair of caliper support arms that straddle an outer edge of a disc rotor in a disc axis direction; a pair of friction pads that are disposed across the disc rotor, each friction pad including a back plate having side portions; and pad return springs each of which is disposed between the corresponding caliper support arm and the corresponding side portion of the back plate, and urges the corresponding friction pad toward an opposite side to the disc rotor when braking is released, wherein each pad return spring includes a back plate attachment portion that is attached to the corresponding side portion of the back plate, and a pad return portion that extends from the back plate attachment portion toward the opposite side to the disc rotor and then bends toward a disc rotor side and that has a distal end abutting against a corresponding side surface, opposite to the disc rotor, of the caliper support arm, the back plate attachment portion of each pad return spring includes a first piece that is disposed on a first surface, on the disc rotor side, of the corresponding side portion of the back plate, a second piece that is disposed on a second surface, on the opposite side to the disc rotor side, of the corresponding side portion of the back plate, and a connection piece that is disposed on an outer end surface of the corresponding side portion of the back plate and that connects the first piece and the second piece, the back plate attachment portion of each pad return spring has a substantially U shape in section, and a part of one of the back plate attachment portion of each pad return spring and the corresponding side portion of the back plate engages with the other, wherein the one of the back plate attachment portion of each pad return spring and the corresponding side portion of the back plate includes an engagement protrusion portion, the other of the back plate attachment portion of each pad return spring and the corresponding side portion of the back plate is formed with an engagement groove with which the engagement protrusion portion engages, the first and second pieces of the back plate attachment portion of each pad return spring are formed with the engagement protrusion portions that bend toward the corresponding side portion of the back plate so as to gradually approach each other as it goes toward the connection piece, the first and second surfaces of each side portion of the back plate are formed with the engagement grooves, friction pad return forces of the pad return springs disposed on a disc entrance side from which the disc rotor enters when a vehicle travels forward are stronger than those of the pad return springs disposed on a disc exit side to which the disc rotor exits when the vehicle travels forward, and the pad return spring attached to a lug piece on the disc entrance side is thicker than the pad return spring attached to a lug piece on the disc exit side.