| 摘要 |
PURPOSE:To combine the metal skin material of a laminated plate with an ordinary steel plate and to obtain sufficient intensity by forming a nugget on the laminated plate with the space between the metal skins of the laminated plate as an electric continuity and performing the spot welding of the laminated plate and ordinary steel plate by changing over the welding circuit. CONSTITUTION:When an electrification is performed via a power source transformer 7 with a switch 8 being at switch contact 8a and a switch 9 neutral, the welding current flows only in the metal skin material 1a, which is heated, a resin plate 1b just under electrodes 3a, 4a is melted with the heat thereof and rejected by the pressurization, and the current flows in a metal skin material 1c as well with the direct contact of the metal skin materials 1a, 1c. As a result a nugget is formed between the metal skin materials 1a, 1c. When switches 8, 9 are changed over to 8b, 9b, the current flows from the electrode 3a to 5a, a laminated plate 1 and ordinary plate 2 are welded, a nugget is formed from the boundary face of the metal skin material 1c and ordinary steel plate 2 and a nugget is formed between the metal skin materials 1a, 1c. |
