To fully automate switching and controlling of welding conditions by making the pressurizing of a welding head numerically controlled and also providing a mechanism for measuring the pressurization.
Using a pulse motor 9 in driving an NC machining mechanism, a ball screw 6 and a ball nut 7 are attached to the motor shaft, enabling an electrode 1 to be positioned at an arbitrary speed. In other words, the electrode is moved at high speed to a tentative origin slightly before coming into contact with an object to be welded; then, after slowly descending to be in contact with the object, the electrode stops at the position where a spring 3 is contracted with a limit switch 13 turned ON inside the head; upon completion of welding, the electrode moves at high speed to the position of the tentative origin, ending a series of operation. Then, with a pressurizing force confirmed using a strain gauge 10, and with the abrasion loss (L0-L1) of the electrode determined, switching is performed for the optimum welding conditions according to the length of an electrode and for the pressurizing timing, as preliminarily obtained from experiments. Thus, stable welding is efficiently carried out without the requirement for human intervention.
TANAKA KIYOBUMI
KOBAYASHI MAKOTO
