Patent ID: 7862129
Filing Date: 2011-01-04
Classification: B60T

Abstract:
1. An electric parking brake system with one cable for a vehicle, the parking brake system comprising: an actuator including an integral housing that is formed by injection molding and has a plurality of sections inside, a power generator including a motor mounted in the housing and rotatable normally and reversely through power supplied depending on operational positions of an operating button, a motion converter including a gear train of a pair of engaged gears rotatable by the motor, an operating force generator including a screw nut fastened to a screw rod rotatable by the gear train and generating axial moving force to operate parking cables, a load sensor that measures axial load generated by the screw rod and transmits the measured load to an electronic control unit, and a vibration absorber mounted in the integral housing to absorb vibration generated by the motor and the gear train rotating, the actuator providing locking and releasing forces to parking brakes, the screw rod being fitted in a joining hole formed through the center of a driven gear of the gear train that is engaged with a driving gear rotated by the motor, and rotated by torque from the driven gear, the screw rod having fitting grooves longitudinally formed to insert restricting protrusions protruding inside the joining hole formed through the center of the driven gear, an extending shaft having a diameter smaller than that of the screw rod is coaxially formed at an end of the screw rod so that the load sensor is provided in the screw rod, and a supporting shaft, having a diameter smaller than that of the extending shaft of the screw rod, coaxially formed at the extending shaft and supported by a supporting member in the integral housing; a fixing plate inserted in an insertion slot of the housing, the fixing plate supporting the supporting member; a connecting cable fastened to the actuator and pullable by axial linear moving force generated by the actuator; left and right parking cables extending from opposite sides of a distributing member to equally distribute the pulling force of the connecting cable into two directions, and connected to respective wheels; and stationary brakes holding the respective wheels by the pulling force of the left and right parking cables to restrict movement of a vehicle.