MOTOR-LOCK PREVENTION DEVICE FOR ASSISTING AN ELECTRICAL STEERING SYSTEM FOR RESTRICTING A DC MOTOR FROM BEING LOCKED BY INSTALLING RELAYS FOR TURNING ON/OFF A POWER UNIT AT BOTH ELECTRODES

摘要

PURPOSE: A motor-lock prevention device for assisting an electrical steering system is provided to prohibit a motor from being locked by cutting off positive and negative voltages supplied to the motor with an ECU(Electronic Control Unit) even if both ends of the motor are short-circuited and the steering system is operated wrong. CONSTITUTION: A motor-lock prevention device for assisting an electrical steering system is composed of a DC(Direct Current) motor(10) for assisting steering operation of the electrical steering system; a first relay(20) coupled between the motor and a positive electrode(50) to turn on/off the supply of positive voltage; a second relay(30) coupled between the motor and a negative electrode(60) to turn on/off the supply of positive voltage; and an ECU(40) for controlling each operation of the first and second relays. When the electrical steering system is operated abnormally, the ECU transmits a cut-off signal to the first and second relays and then the first and second relays cut the positive and negative voltages fed to the DC motor.