Displacement-controlled device null of electrohydraulic servo Drive

摘要

PURPOSE:To attain the control for displacement of a servo drive system over a wide range and with high resolution by controlling a minute displacement detecting means in response to the target displacement of an actuator and the controlling the displacement of the actuator in response to the position of said displacement detecting means. CONSTITUTION:In a servo drive system, a motor 10 is driven by the output signal of a servo amplifier 18 in accordance with the deviation between the target displacement value of an actuator 1 given from a displacement setting part 16 and the present position of a coil 5 of a minute displacement meter. Then the coil 5 is driven toward the target displacement direction of the actuator 1. The relative position between an iron core 7 and the coil 5 is changed with the shift of the coil 5. The signal sent from a servo amplifier 22 is applied to a servo valve 2 with said change of the relative position. Thus the actuator 1 is driven and then a piston 4 is driven. The displacement amount of the piston 4 is equal to the sum of the detected displacement value of the coil 5 and that of a magnetic scale 14.