Servo drive system and continuous working system of press machine

摘要

A continuous working system of a press machine uses a servo motor (30a,30b) as a power source of a ram. An operation shaft (20) which vertically moves the ram is directly driven by using a servo motor (30a,30b) which can generate necessary ram pressure by using a torque based on speed-torque characteristics of a motor (30a,30b). The operation shaft (20) is continuously reciprocated and turned through an angle range corresponding to a distance between a predetermined lower end position required for press working by the ram (22) and a position where the ram (22) is returned from the lower end position and a lower end of the ram (22) is separated from a tool upper surface such that the ram (22) vertically moves between these positions by the servo motor (30a,30b), thereby subjecting a work to a continuous press working.