| 摘要 |
PROBLEM TO BE SOLVED: To suppress deterioration of current density even when core deviation (deviation between a shaft of an electrode and a shaft of a rivet) of an electrode for spot welding occurs, to stably form a nugget having a necessary size, and to ensure necessary connection strength.SOLUTION: A steel-based rivet for different material connection comprising a head part 12 and a shaft part 13, is driven in a light alloy material to punch the light alloy material with the shaft part 13, and at the same time, is subjected to calking connection to the light alloy material, and then is subjection to spot welding with a steel material. At the tip of the shaft part 13 of the rivet, formed are a center projection 14, and an annular projection 15 surrounding the center projection 14 in a circular manner. Or at the tip of the shaft part 13, formed is a plurality of annular projections arranged in a concentric circular manner.SELECTED DRAWING: Figure 2 |
