| 摘要 |
PURPOSE:To reduce the pressure loss by selectively feeding the pressure of a power steering circuit and the pressure of a discharge pipe to a capacity control valve as the pilot pressure with a selector valve, and pilot-operating the capacity control valve with the differential pressure between both pressures. CONSTITUTION:When there is no loading and no load is applied to a loading circuit 21, a selector valve 50 feeds the pressure P3 of a power steering circuit to a capacity control valve 80 as the feed pilot pressure P2. The position of the capacity control valve 80 is held by the differential pressure between P3 and the discharge pipe pressure P1, the pump oil quantity 35 is automatically adjusted, and the flow is maintained. When loading is started and the pressure P3 of the loading circuit 21 rises, the selector valve 50 feeds the discharge pipe pressure P1 to the capacity control valve 80 as the feed pilot pressure. The differential pressure of the capacity control valve 80 is dissolved, and the discharge oil quantity is increased. A throttle generating the differential pressure on the selector valve 50 itself can be prevented, resistance is eliminated, and the pressure loss is reduced. |
