| 摘要 |
A variable assist power steering system comprises a control valve including valve elements relatively displaceable in response to a steering torque to define therebetween two parallel fluid flow paths connected between the fluid source (10) and the fluid reservoir to produce pressure difference in the power cylinder in response to the steering torque. The control valve includes a plurality of bypass paths, each arranged in parallel to one of plurality of serially arranged variable flow orifices forming the two flow paths and each provided with an externally controlled variable flow orifice valve which is operable responsive to a vehicle speed. |
