CONTROLLER FOR HYDRAULICALLY-OPERATED MACHINE

摘要

PROBLEM TO BE SOLVED: To improve a setting property at all times no matter which spool stroke position a flow control valve is displaced to in a hydraulically-operated machine. SOLUTION: A controller for a hydraulically-operated machine is provided with a bleed-off circuit 15 discharging a pressure oil supplied to a hydraulic actuator from a hydraulic pump 1. The bleed-off circuit 15 is provided with a variable bleed valve 13 which changes a flow rate of the pressure oil discharging from a flow control valve 5 through a line 11. The variable bleed valve 13 is controlled such that a flow rate of discharged oil becomes higher when a discharged Pp of the hydraulic pump 1 becomes higher.