| 摘要 |
An object of the present invention is to, in an electric disk brake, prevent uneven abrasion of a disk rotor due to contact of the disk rotor to a brake pad when brake is not in operation. In the present invention, a rotation of an electric motor is slowed down by a differential speed reducing mechanism, and is converted to a linear motion of a piston by a ball ramp mechanism. Brake pads are pressed against a disk rotor by the piston to generate a brake force. When brake is not in operation, the piton is retracted by a reverse rotation of the electric motor so that a predetermined pad clearance is maintained. When brake is not in operation, a pad-retracting-control electric current is supplied to the electric motor so that the piston is biased backward while being maintained in one position. When brake is not in operation, contact of the disk rotor to the brake pads due to runout of the disk rotor triggers smooth retracting of the piston, whereby uneven abrasion of the disk rotor can be prevented. |
