Braking torque control apparatus

摘要

A pair of shoes are expanded by driving an electric brake motor (30). Due to the friction engagement of the shoes with a drum inner peripheral surface, a braking force is applied to a wheel. An actual braking torque is detected by a strain sensor (314) that detects the load applied to an anchor pin. Through a feedback control using the actual braking torque, the electric motor (30) is driven and controlled so that the actual braking torque becomes equal to a target braking torque that is determined in accordance with the amount of operation of a brake pedal (40). When the actual braking torque is undetectable, for example, during a stop of a vehicle, the electric motor (30) is driven and controlled through an actuating force control using the current through the electric motor (30) that is detected by a motor current sensor (31). The braking torque control apparatus controls the actual braking torque to a magnitude corresponding to brake operation, regardless of the magnitude of the coefficient of friction between a friction engagement member and a brake rotor. Even when the braking torque is undetectable, the apparatus executes brake control in a good manner. <IMAGE>