Servo drive system and continuous working system of press machine

摘要

A servo drive system of a press machine uses a servo motor (30a,30b) as a driving source of a ram (22). The servo motor (30a,30b) uses a torque based on speed-torque characteristics of a motor. Necessary ram pressure can be generated without utilizing inertia of a mechanism. The system employs the servo motor (30a,30b) in which if a load is received from a work during a lowering operation of the ram (22), motor speed is reduced according to the load, thereby reducing the lowering speed of the ram (22). The servo motor (30a,30b) directly drives an operation shaft (20) which vertically moves the ram (22).