| 摘要 |
A controller (18) controls an AC servomotor (39) to reverse the rotation of a bidirectional piston pump (31) so as to reverse the vertical movements of a ram (5U). At this time, a command generator (65) of the controller (18) maintains the ram (5U) at a constant speed for a predetermined warm-up time after a reverse of the ram movement and change the ram speed to a predetermined speed. A command position counter (67) reads the ram position from the ram speed pattern, and an adder (73) sums the read value and the actual position of the ram (5U) detected by a position detector (11) to control the rotation of the AC servo motor (39). <IMAGE> |
