VEHICLE STEERING GEAR

摘要

A vehicle steering gear has a steering mechanism for steering steered wheels by a steering wheel operated by the driver and a sub steering angle superimposition mechanism controllable electrically. A target sub steering angle is set according to a steering wheel angle, and a motor of the sub steering angle superimposition mechanism is driven/controlled just corresponding to the target sub steering angle. Without regard to the state of drive control, the rotation of the motor (212) is stopped. A short-circuit relay (13) which short-circuits the terminals of the motor (212) is provided and made to operate so as to short-circuit the terminals of the motor (212) through a short-circuit relay drive means (14) depending on the type of a failure detected by a failure detection means (18). This stops the rotation of the motor (212). When the power supply to the vehicle steering gear is shut off, the short-circuit relay (13) operates without the power supply so as to short-circuit the terminals of the motor (212).