| 摘要 |
<p>The number of sub-parts of a closed structure part and the number of steps for manufacturing the closed structure part can be reduced and, therefore, the closed structure part can be efficiently manufactured. In a hemming press step, a punch 84 is further lowered, and a pair of flange portions 20 and 22 is inserted into a slit clearance 102. At that time, hemming prongs 28 are bent and, each of the hemming prongs 28 sandwiches the flange portion 22. Thus, the flange portion 20, which is one of the two flange portions, is joined to the other flange portion 22. At the same time, a pair of press forming surfaces 96 of the punch 84 presses a metal plate and performs press-forming on a pair of shoulder portions 26 of a blank 24 into a predetermined shape. In this way, the flange portion 20, which is one of the two flange portions, can be fixed to the other flange portion 22 using the hemming prongs 28 (hemming joint). In addition, the pair of shoulder portions 26 of the blank 24 can be press-formed into the predetermined shape.</p> |
