DISC BRAKE DEVICE AND OPERATION CONTROL METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a disc brake device and a operation control method thereof allowing to automatically reduce pressure when failure occurs during the press ing operation of a motor. SOLUTION: A caliper 14 of a disc brake device 12 is provided with an electric actuator 10 provided with a ball screw 60 to convert torque of an ultrasonic monitor 62 to rectilinear motion. A carrier plate 92 connected to an electromagnetic brake 127 through a pair of planet gears 109 and a supporting aluminum plate 124 is rotatably inserted into a ball screw 56. The electromagnetic brake 127 is under an exciting condition during pressing operation of an inner pad 16 and the carrier plate 92 is secured. The exciting condition of the electromagnetic brake 127 is cancelled at the time of failure of the ultrasonic motor 62 and the carrier plate 92 becomes rotatable, and the ball screw 56 is allowed to move to a direction for reducing pressure.