| 摘要 |
PURPOSE:To prevent the generation of creases and make the weight of blank lighter by inserting a lightweight sheet in the center between two exceedingly thin steel sheets, making the peripheral section of the exceedingly thin steel sheets consist of three layers through another exceedingly thin steel sheet, and welding them in a body. CONSTITUTION:A central blank 1d that is a sheet made of plastic is inserted in the center between the upper and lower blanks 1a and 1b consisting of exceedingly thin steel sheets and is made to adhere to each other with a bonding agent 1e. Besides, a central peripheral section blank 1c made of an exceedingly thin steel sheet is inserted in the peripheral section between the upper and lower blanks 1a and 1b and is made to adhere to each other with the bonding agent 1e. Moreover, the said peripheral section is welded by a laser beam and the three blanks 1a, 1b, and 1c of the upper side, lower side, and the central peripheral section are integrated firmly. |
