| 摘要 |
PURPOSE:To prevent the rise of cylinder differential pressure around the neutral of a steering wheel so as to improve rigidity around the neutral and reduce the discharge flow of a pump at the power assisting time so as to save energy. CONSTITUTION:A power steering is provided with a valve means for increasing the flow of operating oil by the rise of load pressure caused by the steering of a steering wheel, and each variable throttle of a first control part 33 formed of a first bridge circuit C1 is formed of a semi-center open valve. Out of the respective variable throttles of a second control part 34 formed of a second bridge circuit C2, the variable throttle on the pump 10 side is formed of a center closed valve, and the variable throttle on the reservoir 11 side is formed of a center open valve. Each variable throttle of the first control part is set in such relation as to start closing almost simultaneously with the time of the pump side variable throttle of the second control part starting to open. |
