| 摘要 |
PROBLEM TO BE SOLVED: To provide a rear wheel steering system exhibiting high reliability in relation to locking of a rear wheel turning shaft.SOLUTION: A rear wheel steering system 4 includes a rear wheel turning shaft that turns rear wheels by moving in an axial direction, a turning shaft drive unit 32 that moves the rear wheel turning shaft in the axial direction, and an ECU 71 that controls activation of the turning shaft drive unit 32. The turning shaft drive unit 32 includes a turning motor 34 formed with a brushless motor, and converts the rotation of a rotor 78 into an axial movement of the rear wheel turning shaft by means of a rack-and-pinion mechanism. The ECU 71 includes a motor drive circuit 76 having plural FETs 81a to 81f interconnected, and a microcomputer 75 that outputs a motor control signal with which the FETs 81a to 81f are turned on and off. For retaining the turning angle of the rear wheels at a neutral position, the ECU 71 turns on the FETs 81a, 81b, and 81c on the side of a power supply, turns off the FETs 81d, 81e, and 81f on the side of a ground, and thus restricts the rotation of the rotor 78. |
