| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and an apparatus for press-forming an aluminum alloy sheet by which forming is made possible even when a formed article is large-sized panel of automotive parts such as an oil pan and member parts or the like having a shape which is difficult to form. SOLUTION: In the method for press-forming the aluminum alloy sheet 30 into a panel of the formed product having a stepped part (punched portion 14) where the height of cross sections of mutual formed surfaces (punching portions 12, 13) having planar upper parts is suddenly changed. A part of the punching portion 13 on the side where the height of the cross section of a first punch 11 is lower is divided into a second punch 15 and supported elastically, and, when starting forming, the relative position of the second punch 15 to the first punch 11 is preliminarily shifted to the side of a die 22 and the second punch 15 is brought into contact with the portion 33 of the formed surface on the side where the height of the cross section is lower in the sheet 30, while the second punch 15 is elastically lowered as the forming progresses. COPYRIGHT: (C)2009,JPO&INPIT
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