SYSTEM FOR PROTECTING MISSING-WELDING OF SPOT WELDER

摘要

The present invention relates to a system for preventing a welding spot from being omitted of a spot welding machine, wherein the spot welding machine includes a lower welding tip and an upper welding tip vertically moving on an upper part of the lower welding tip and welds an object to be welded being transferred between the lower and upper welding tips by pressuring and conducting the object. The system for preventing a welding spot from being omitted of a spot welding machine comprises: a first photosensor which is arranged on one side of the spot welding machine and senses the state of the object to be welded inserted toward the spot welding machine; a conduction sensor which is electrically connected to the upper welding tip to recognize the state of conduction of the object to be welded transferred between the upper and lower when the upper welding tip is lowered; a second photosensor which is arranged on the other side of the spot welding machine to sense the state of the object to be welded discharged from the spot welding machine and transferred; and a controller which controls the upper welding tip by comparing an output value and a set value with a counter set value and a counter output value inputted for each one cycle of the first photosensor, the conduction sensor, and the second photosensor in order in advance, respectively.