| 摘要 |
<p>PURPOSE: To efficiently reduce power consumption quantity by connecting a three-way pressure reducing valve to a main pipeline and a return pipe on the primary side thereof and connecting the same to a flow rate control valve on the secondary side thereof and providing a pressure compensation valve controlling the spool of the three-way pressure reducing valve between the vent line connected to the primary side and the pressure feedback line on the secondary line of the flow rate control valve. CONSTITUTION: At a time of flow rate match control, a communication pipeline 37 is closed by an opening and closing valve 38 and the pressure of the operation oil from an accumulator 7 or oil pressure pump 1 is reduced to the pressure calculated by adding the pressure sent by a pressure compensation valve 34 to the load pressure of an actuator by a three-way pressure reducing valve 31 and the operation oil is supplied to the actuator while controlled in its flow rate by a flow rate control valve 5. At a time of pressure match control, the opening and closing valve 38 is opened and the operation oil flows to the flow rate control valve 5 through the communication pipeline 37 to be supplied to the actuator. At this time, the pressure compensation valve 34 controls the spool 31a of the three-way pressure reducing valve 31 so that the pressure of the operation oil of the vent line 33 becomes pressure wherein set pressure is added to the load pressure of the actuator and, at a time of release control, all of solenoid changeover valves 2 are closed.</p> |
