PURPOSE: To lessen backlash errors or the like by controlling an oil amount to a hydraulic cylinder of a second feeder with a difference between a command acceleration signal to a first feeder for locating a mover and an acceleration signal of the mover.
CONSTITUTION: A position-speed signal 20 from a controller 10 is sent to a motor 4 through a motor control unit 9 to locate a mover 1 by a ball screw 3 and a nut 2, while a position-speed detecting signal 21 is fed back from the motor 4. Then, pistons 14a, 14b are driven through a pulley 17, timing belt 19, pulley 18, ball screw 16, nut 15 and bracket 26 to give a drive force to the mover 1 by hydraulic cylinders 5a, 5b. Also, a pressure control unit 6 sends to the hydraulic cylinders 5a, 5b a flow corresponding to the deviation between a command acceleration signal 24 from the controller 10 and an acceleration signal from an acceleration detector 25 of mover 1 according to both signals. Thus, wind-up and backlash errors can be reduced and a compact hydraulic cylinder can be provided.
HAYAMA YASUNOBU
TAMARU TOSHIAKI
