High-speed driving method for pressure cylinder e.g. spot welding gun cylinder involves controlling servo valve to prevent deviation between set intermediate stopping position and detected position of piston rod

摘要

A position detector senses the operation position of a piston rod (13) and sends a signal to a control apparatus (8) which controls a servo valve (41) to obtain no deviation between the detected position and a set intermediate stopping position. The piston rod is thereby stopped at the set position and same pressures are supplied to pressure chambers (35). A piston (12) is driven during an advancing working step by the air pressure discharged from the servo valve to move the piston rod to a forward stroke end and perform a pressurizing operation. The piston rod is retreated to the intermediate stopping position during an intermediate stopping step. An Independent claim is also included for a high-speed driving apparatus.