ROLLING DOWN DEVICE FOR ROLLING MILL

摘要

PURPOSE:To control a position stably and with high accuracy irrespective of elongation of stroke of a hydraulic cylinder. CONSTITUTION:A position setting equipment 2 gives a position command of a hydraulic cylinder 10 through a signal from an automatic sheet thickness controller 1 to a subtraction circuit 3 as a target value. The position of the piston of the hydraulic cylinder 10 is detected by the position detector 11 and given to the subtraction circuit 3 as an oil pillar S. A motion control signal E is given to a servo amplifier 8 through a controller 4 having a transfer function K and an oil pillar compensatory circuit 7 having a compensatory coefficient of alpha. A servo valve 9 is actuated by an output from the servo amplifier 9 to displace the hydraulic cylinder 10. The compensatory coefficient alpha in the hydraulic pillar compensatory circuit 7 is generated by a compensatory value generating circuit 6 responding to the oil pillar S.