Patent ID: 8997947
Filing Date: 2015-04-07
Classification: F16D

Abstract:
1. A friction brake device for a vehicle, comprising: a hydraulic brake unit including a piston member that is configured to be movable by an action of brake fluid pressure and to press a friction member by advancement; an electric brake unit including a nut member that is configured to be relatively movable in a piston movement direction with respect to the piston member by a motor and to press the piston member by advancement, and configured such that a position of the nut member is maintained with respect to the motor when the motor is not in operation; a piston return mechanism including a biasing member that is arranged so as to make biasing force, oriented in a retreat direction, elastically act on the piston member in accordance with an advancement amount of the piston member from a movement start position with respect to the nut member, the movement start position of the piston member being determined by the position at which the nut member is maintained, and the advancement amount being provided by an action of the hydraulic brake unit; and a controller for controlling the motor, wherein the controller determines whether an adjustment permission condition associated with a wear amount of the friction member is satisfied, and when the condition is satisfied, the controller allows the motor to perform a relative position adjustment of the nut member with respect to the piston member, and wherein the relative position adjustment includes updating the position at which the nut member is maintained when the motor is not in operation.