CONTROLLING METHOD FOR DRIVING WEDGE TYPE OIL HYDRAULIC SCREW DOWN DEVICE

摘要

PURPOSE:To control the driving of a titled device with high responsiveness, fast responsiveness and control accuracy by so constituting said device that a constant frequency signal is superposed on a position control signal and the piston of an oil hydraulic cylinder for driving a wedge is finely oscillated by said signals. CONSTITUTION:Since a constant frequency signal E0 is superposed on an actual position Ef together with a position control signal Ea in the input part of a control system, the deviation signal epsilon inputted to a servo amplifier 11 includes the constant frequency signal component. Then the spool of a servocontrol valve 9 moves to the position corresponding to the level of the signal Ea and moves back and forth finely at 1/fL frequencies in said position. Therefore the piston 7a of an oil hydraulic cylinder 7 is changed over and controlled under oscillation and a wedge 5 oscillates finely in horizontal directions at all times. Thus the friction and sticking phenomena on the surface of the wedge 5 are eliminated, and the device responds surely and quickly to any minute output change of the valve 9.