PURPOSE: To adjust a projecting stroke numerically easily and accurately by comparing the position of the projection of a hydraulic ejector output from a positional sensor with a stoppage command position and outputting a stoppage command to a solenoid valve when the position of oil projection reaches the stoppage command position.

CONSTITUTION: A controller is operated. A driver 9 controls the opening of a flow-rate proportional valve 6 in response to projecting speed (x). An ejector cylinder 2 is projected and operated, and a hydraulic ejector 1 is projected at speed (x). An arithmetic unit 8 operates a stoppage command position (l), and outputs it to a comparison circuit 11. A position sensor 12 detects the projecting stroke l' of the hydraulic ejector 1, and outputs it to the comparison circuit 11. When the projecting stroke l' of the hydraulic ejector 1 reaches the stoppage command position (l), a stoppage command is emitted to an ON- OFF circuit 14 from the comparison circuit 11, and a solenoid (a) is turned OFF and a solenoid valve 5 is brought to a neutral state. The hydraulic ejector 1 is inertial-moved only by quantity corresponding to projecting speed (x), and stopped.