Patent ID: 7559412

Claim:
A disc brake apparatus comprising: an actuator operating in accordance with an operation force of a brake pedal; wherein the actuator is a motor driven actuator; a braking piston fitted into a cylinder portion of a caliper to be axially slidable, the braking piston being axially driven by the actuator so as to push a pad toward a disc rotor; an anchor mechanism for taking out, as an anchor oil pressure, a friction force in a circumferential direction of the disc rotor between the pad and the disc rotor; a servomechanism for converting the anchor oil pressure to a servo oil pressure, which is applied to the braking piston; changing means provided in the servomechanism and adapted to increase or decrease the servo oil pressure, the changing means comprising a first solenoid valve which establishes or shuts off communication between the anchor mechanism and the servomechanism, and a second solenoid valve which establishes or shuts off communication between the servomechanism and a reservoir tank; a sensor for detecting the anchor oil pressure; and control means for controlling the first and second solenoid valves electrically in accordance with the operation force and the anchor oil pressure to increase the servo oil pressure for bringing the anchor oil pressure toward a set value determined by the operation force when the detected anchor oil pressure is lower than the set value and to decrease the servo oil pressure for bringing the anchor oil pressure toward the set value when the detected anchor oil pressure is higher than the set value.