Welding control apparatus including a pressure regulating valve operated in accord with predetermined schedule of variations of a welding force control variable

摘要

A welding machine controller for controlling the welding operation of a welding machine controls welding force applied to a workpiece by directly controlling a pressure regulating valve which regulates the pressure of working fluid supplied to a power cylinder for applying a welding force to the workpiece. The welding machine controller further controls squeeze time, welding time, hold time, OFF time, cooling time and welding current. The welding force is regulated in a single step or in a plurality of steps during one welding cycle according to the quality and/or thickness of the workpiece.