FOUR-WHEEL-STEERING DEVICE FOR VEHICLE

PURPOSE:To avoid giving a feeling of physical disorder in the operation of a steering wheel by enlarging the assist power of an assist means all the more with an increase in rear wheel steering angle toward the same phase as steering, according to a signal from a rear wheel steering condition detecting means. CONSTITUTION:A stepping motor 44 and an electric motor 25 as an actuator are so made as to undergo drive control with a drive signal sent from a control unit 50. This control unit 50 is equipped with an assist power operation part 66 for computing an assist power for making approximately constant a driver's steering feeling depending upon a rear wheel steering condition, regardless of this condition, and a drive part 67 for sending a drive signal for the electric motor 25 upon receipt of a signal from said assist power operation part 66. In this assist power operation part 66, when rear wheels are steered to a reverse phase, the assist power of front wheel power steering mechanism is all the more reduced with an increase in the steering angle of the reverse phase.