| 摘要 |
PURPOSE:To reduce the dimension of a servo motor by installing a hydraulic actuator for assisting the steering force of a rear wheel, in the captioned apparatus by which the front and rear wheels can be steered and the steering control for the rear wheel is executed by the servo motor. CONSTITUTION:A servo motor 13 is driven through a controller 12 according to the output signal of a steering-angle sensor 11 which is output by the operation of a steering wheel 9, and a rear wheel 4 is steered through a rear-wheel steering mechanism 3 constituted of a pinion 8 and a rack gear 7. A power cylinder apparatus 15 is installed in relation to the rack gear 7. A hydraulic control valve 19 is installed onto the output shaft 14 of the servo motor 13, and the force necessary for steering the rear wheel 4 is assisted by feeding the oil pressure discharged from a hydraulic pump 16 into the left chamber port A or the right chamber port B of the power cylinder apparatus 15. Therefore, the light steering for the rear wheel 4 is permitted irrespectively of the use of the small-sized servo motor 13. |
