SPOT WELDING APPARATUS FOR PREVENTING PRESSURE MARK OF PLATE AND SPOT WELDING METHOD THEREOF

摘要

According to an embodiment of the present invention, the spot-welding device to prevent a pressure mark on one surface comprises: a first electrode part positioned on one surface of an overlap part wherein a first panel and a second panel are overlapped; a second electrode part positioned on an other surface of the overlap part to electrically be connected to the first electrode part having one end which has a larger diameter than an end of the first electrode part, and a structure to support the overlap part; a current control part electrically connected to the first and the second electrode part to electrically connect the first and the second electrode part to each other when a current is applied; and a pressing part connected to the first and the second electrode part providing a pressure to the first and the second electrode part to press the overlap part until a temperature of the overlap part lowers to a recrystallization temperature or less from a time when the first and the second electrode part is electrically connected to each other. The end of the first electrode part has a smaller area than an area of a melted portion in the electrically connected portion, and an end of the second electrode part has a greater area than the melted portion in the electrically connected portion to support the other surface of the overlap part; thus preventing deformation of the other surface of the overlap part.