| 摘要 |
PURPOSE:To enable expected cushion control by detecting the pressure on return side of a hydraulic actuator to find the target displacement of a control spool of a cushion valve, and gradually compensating for a difference between the detection value and the actual control valve. CONSTITUTION:Pressure P2 on return side of a hydraulic actuator is detected to be input through an initial speed detecting portion 39 and a speed reduction curve decision portion 40 in an integrated circuit 14 to find the target displacement of a control speed of a cushion valve D. Further, the value is feedbacked to a speed detecting portion 43 to gradually compensate for a difference between the actual control value and the target control value. Thus, a speed reduction characteristic is decided according to a hydraulic system, and besides the collision speed at the stroke end can be controlled arbitrarily to enable expected cushion control. |
