| 摘要 |
<p>PROBLEM TO BE SOLVED: To properly assure molten state on a thin steel sheet side when a projection bolt is welded to the thin steel sheet by electric resistance-welding.SOLUTION: A method for welding a projection bolt 1, which is formed from a shank 2, a circular widened diameter part 3, and a projection 4 for deposition comprising an initial melting part 4A having a taper portion 6 and a main melting part 4B, to a thin steel sheet 8 by an electric resistance-welding, is characterized in that welding is carried out in the state such that a ratio of a circular area of the initial melting part 4A to a plate thickness of a steel plate component 8 is set within a range from 45 at which a molten amount of the steel plate component 8 in a plate thickness direction becomes a predetermined lower limit value by a pressure of a molten metal 14, to 105 at which a molten amount of the steel plate component 8 in the plate thickness direction does not exceed a predetermined upper limit value by the pressure of the molten metal 14. thus, the molten amount of the steel plate component 8 can be properly assured.</p> |
