Spot joining method and spot joining device

摘要

A spot joining device comprises a joining tool, an induction motor for rotating the joining tool, a servo motor for vertically moving the joining tool along an axis of the joining tool, and a receiving member placed opposite to the joining tool. The joining tool includes a short-column shaped shoulder and a pin protruded downwardly along the axis from a central portion of a lower face of the shoulder at a tip end portion thereof. Two works such as aluminum alloy plates are lapped and placed on a receiving member. When the joining tool is rotated and moved downwardly, a joint spot of the works is heated and softened due to friction heat generated by the rotating pin. Thereby, plastic flow occurs in the vicinity of the joint spot. The vicinity of the joint spot is stirred and the works are fused at the joint spot. Thus, the works are spot-joined.