Control system for synchronizing multiple presses in a line

摘要

A control system for a press line containing a plurality of presses for performing successive operations on the same workpiece has a plurality of computer control units, each of which controls the movement of one of the presses and the workpiece transfer mechanisms associated therewith via repetitive automation cycles which correspond to and control repetitive press cycles. One of the computer control units selected as a reference unit, and all the computer control units, including the reference unit, produce a synchronizing signal at a common predetermined point in the automation cycles thereof. The synchronizing signal from the reference unit is compared with the synchronizing signal from each of the other units to determine whether the other units are lagging or leading the reference unit. The cycle times of the leading and lagging units are then adjusted accordingly.