| 摘要 |
PURPOSE:To prevent unevenness of fusion welding by utilizing Curie temp. of magnetic alloy to heat a fusion welding part and holding the heating temp. constant. CONSTITUTION:Firstly a plate 10 made of thermoplastic resin is prepared in which magnetic alloy 12 having the prescribed Curie temp. is formed in at least one side end in the crosswise direction. The one side end of this plate 10 is overlapped on the other side end. When high-frequency current is imparted to this magnetic alloy 12, it is heated by skin effect and its temp. is raised. When the magnetic alloy reaches Curie temp., magnetic permeability of magnetic alloy 12 is suddenly made small and current does not hardly flow and the temp. of magnetic alloy is not raised higher than Curie temp. Furthermore when the temp. of magnetic alloy is lowered by heat dissipation, current starts to again flow in the magnetic alloy 12. Since such motion as this is repeated, the temp. of magnetic alloy 12 is substantially held at the prescribed Curie temp. Therefore the interval of the overlapped end parts is welded by fusion at the prescribed Curie temp. or the vicinity thereof. |
