| 摘要 |
A bolt for projection welding, and method of welding the same, adapted to form a portion of large fusion depth in narrow region and ensure junction to a steel sheet part in other portions, thereby realizing high weld strength and stable state of junction. Bolt (1) is composed of shaft part (2), enlarged diameter part (3) and fusion bonding projection (4), the fusion bonding projection (4) consisting of initial fusion part (4A) provided at its end face with taper (15) and, continuous therefrom, main fusion part (4B). Welding current for fusion of the fusion bonding projection (4) only is passed through the fusion bonding projection (4). There is made such an arrangement that upon pressurization of the fusion bonding projection (4) against steel sheet part (9) and subsequent current passage, the region of the fusion bonding projection (4) is fusion bonded to the steel sheet part (9) and simultaneously end face (6) of the enlarged diameter part (3) positioned on the outer circumferential side of the fusion bonding projection (4) joins surface (9A) of the steel sheet part (9). As a result, good welding with appropriate state of fusion can be realized. |
