Method and apparatus for controlling pressurization of spot welding gun

摘要

PURPOSE:To detect the overload caused by an obstacle in a spot welding process. CONSTITUTION:The pressurizing control method is prepared for a spot welding gun so that an electrode tip 33 is moved by the revolution of a servo motor 26 and an welded object 90 is pressurizing. The position of the tip 33 and the current of the motor 26 are monitored in a pressurizing operation state of the tip 33. Then an overload state is decided if the current of the motor 26 exceeds the prescribed value K set previously while the distance between both electrode tips 24 and 33 approximates to the total plate thickness of the object 90 set at the shooting position of the welding gun.