| 摘要 |
PURPOSE:To perform a free control over a speed of actuater which is operated at a minute speed by a method wherein a pressure compensation valve and a directional change-over valve are integrally assembled. CONSTITUTION:When a spool 37 of a direction change-over valve 21 is operated to move in a leftward direction, pressurized fluid flows from an inlet port 23 into an actuater 32 through an inner passage 30 of a control spool 26 of a pressure compensation valve 20, check valve 28, fixture 29, spring chamber 40 and outlet port 34a. A difference in hydraulic pressure is generated between the upstream and downstream sides of a fixed throttle 29, the fluid pressure at the upstream side acts upon the pressure chamber 24 through the inner passage 30 and the fluid pressure at the downstream side acts in the spring chamber 40. Thus, the control spool 26 is moved in a leftward direction so as to form a throttle delta1, a discharged pressure fluid from the hydraulic source 5 is discharged into the tank 6, and then a control spool 26 is balanced to cause the discharge hydraulic fluid to show the same value as that in the spring chamber 40. The hydraulic fluid is supplied in a flow rate corresponding to an opening area of the fixed throttle 29 and the actuater 32 starts to operate in a direction indicated by an arrow A at a speed corresponding to the flow rate. |
