| 摘要 |
PURPOSE:To provide a satisfactory rear wheel steering operation with no special device being added, by disposing third variable orifices in a control valve in a power steering unit. CONSTITUTION:In addition to pump side variable orifices a-1, b-1 and two drain side variable orifices a-2, b-2, there are disposed two third variable orifices which carry out their open and close operations, reverse to each other. Further, rear wheel steering ports E, F are provided in a hydraulic system for a rear wheel steering unit. When the steering is made rightward, the variable orifices a-1, a-2, a-3 are throttled while the variable orifices b-1, b-2, b-3 are opened, greatly. With this arrangement, the pressure at a port C becomes higher than that at a port D while the pressure at the port E becomes higher than that at the port F, thereby both front and rear wheels may be steered. |
