| 摘要 |
PURPOSE:To steer the rear wheels in the same and opposite phases as/to the front wheels steering angle by furnishing a direction control valve to switch over a hydraulic circuit in interlocking with a front wheels steering device, operating a hydraulic actuator with oil pressure which is transmitted via said control valve, and thereby performing steering of the rear wheels. CONSTITUTION:When a steering wheel 24 is turned counterclockwise to swing the head of car to the left, an oil line is switched over by a control valve 27, and a piston 29 of a power cylinder 26 moves to right to steer the front wheels 21 leftwise. At the same time, a spool 37 of a hydraulic selector valve 33 is moved to right according to the pressure difference between the left and right chambers 30a, 30b of said power cylinder 26. Here a smaller steering angle of front wheels corresponds to smaller amount of spool motion, and at this time, a control valve body 45 of a direction control valve 43 moves to right for a smaller distance, whereabout larger corresponds to larger. Thus the flow path in a hydraulic circuit 58 is switched over. Thereby a piston 72 of a hydraulic actuator 63 for steering the rear wheels is moved to the left/right, and the rear wheels 22 are steered in the same phase as/opposite phase to the front wheels 21. |
