Patent ID: 7734408

Claim:
An electric parking brake system, comprising: a drum brake that includes a drum which rotates together with a wheel of a vehicle and of which an inner peripheral face is used as a friction face; a shoe which is fitted to a backing plate that is a non-rotating body so as to be movable relative to the backing plate, and which has a friction member on an outer peripheral face; and a pushing mechanism that pushes the shoe against the friction face to suppress a rotation of the drum; an electric motor; a motion conversion mechanism that converts a rotation of a rotating shaft of the electric motor into a linear motion of an output member of the motion conversion mechanism; a cable that is connected at one end to the output member of the motion conversion mechanism, and that is connected at the other end to the pushing mechanism; a maintaining mechanism that maintains a friction member pushing force that is a force with which the friction member is pushed against the friction face in the drum brake, when electric current is not supplied to the electric motor; and a tension control unit that controls a tension of the cable by controlling the electric motor such that the friction member pushing force in the drum brake is controlled, wherein the tension control unit includes an inclination-based target value setting unit that executes control such that the tension of the cable approaches a target value, and that sets the target value to a larger value when the vehicle is maintained at a standstill on a downhill slope than when the vehicle is maintained at a standstill on an uphill slope, even when an absolute value of an inclination angle of the uphill slope and an absolute value of an inclination angle of the downhill slope are equal to each other and a drive power is not applied to the vehicle.