| 摘要 |
PURPOSE:To enhance high-speed stability, by operating a control spool depending on the pressure rise in a supply passage to alter and control the cross-sectional area of an orifice to reduce the rate of flow to a power steering gear in high-speed running. CONSTITUTION:A valve fitting hole 11 is provided in a pump housing 10. The hole 11 is fitted with a spool valve 17, which regulates the degree of communication between a supply passage 14 and a bypass 15. A union 12 is screw-engaged in the housing 10. A restrictor 24, which has orifices 25, 26, and a control spool 30 for reducing the cross-sectional area of the orifice 25, are installed in the union 12. The union 12 is provided with a pressure inlet port 36. When the pressure in the supply passage 14 has risen, the spool 30 is moved leftward by oil pressure from the inlet port 36 to reduce the cross-sectional area of the orifice 25. The passages 14, 15 are connected to each other by the rightward movement of the spool 17 so that working oil in the supply passage 14 is released into the bypass 15. |
