| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method capable of efficiently forming a panel. <P>SOLUTION: The laser beam welding of reinforcing materials 26 and an outside sheet 24 is performed by continuously emitting the laser beam 32 to the flanges 28 after bringing the flanges 28 of the reinforcing material 26 into contact in a predetermined position on the side of the rear face 24a of the outside sheet 24. Because heat input by the laser beam welding is one-sided to the side of the rear face 24a of the outside sheet 24, thermal stress so that both ends of the outside sheet are upward warped is generated by the strain energy caused by the heat input when four reinforcing materials 26 are welded to the outside sheet 24. The outside sheet 24 is curved on the side on which the reinforcing materials 26 are welded by the thermal stress by welding. In such a case, the outside sheet 24 is curved at a certain curvature which is determined by the heat gain given by the laser beam welding. In this way, it is not necessary to separately perform a stage where for making the outside sheet 24 curve before welding the reinforcing materials 26, so that the efficiency of forming the panel can be increased, thereby reducing the cost. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
