| 摘要 |
<p>PURPOSE:To permit the confluence of fluids from two pumps by the use of single switching valve in order to reduce the cost by providing a shut-off valve operating upon perceiving a change in oil pressure due to the operation of a switching valve for confluence. CONSTITUTION:When switching the switching valves 21 or 22, pressurized oil from the pump P1 is supplied to the actuators 31 or 32, and return oil is recycled to the tank circuit 47. Also, when switching the swtiching valves 25-27 likewise, the actuators 35-37 are, respectively, driven by the pressurized oil from the pump P2. Subsequently, in case where the actuator 33, for example, is driven by the confluent fluids from the pumps P1 and P2, the switching valve 24 is situated at neutral position and the shut-off valve 56 is moved to the opened position 56A. And, when switching the switching valve 23, pressurized oil from the pump P1 is flowed into the actuator 33 through the check valve 53 and also the pressurized oil from the pump P2 is flowed into the actuator 33 through the center by-path circuit 42, the check valve 52, and the shut-off valve 56.</p> |
