| 摘要 |
PURPOSE:To control a deforming a state of a caulking member, and to improve coupling strength by controlling a position of the highest temperature part which forms the center of a buckling deformation of the caulking member. CONSTITUTION:When the first electric conduction is started while pressing a caulking member 4, the caulking member 4 is heated and softened gradually, deformed and contacts a base material 3 in a through-hole 5. In this state, when the second electric conduction having a current value of about half of a steady state current by which the temperature of the member 4 falls is started, the member 4 lowers its temperature and is brought to thermal contraction. Contact of the member 4 with the base material 3 becomes rough, and a heat transfer rate to the base material 3 from the member 4 becomes low. In such a state, the highest temperature part moves gradually to a part where heat is scarcely taken away. When the third electric conduction is executed by the steady state current in order to execute a buckling deformation around this highest temperature part, the member 4 rises in temperature again, is deformed, an the buckling is started. Also, a gap 6 between the member 4 and an expanded diameter stepped part 5A is eliminated.
|
