PRESS FORMING DIE DEVICE AND PRESS FORMING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a press forming die device and a press forming method using the same by which the dimensional accuracy of a press formed article including stretch-flange forming is improved without increasing stages than in the conventional practice even when using high-tensile strength steel as a base stock and also stretch-flange crack is surely prevented. SOLUTION: This device is a die device which has a punch, a die and a blank holder 5 and is used for press-forming including stretch-flange forming. In this press-forming die device, an excess thickness-imparting part 7 which has at least a circumferential difference increasing part where difference between a plane and the circumference is gradually increased toward the anti-punch side from the shoulder 6 of the die is provided in a portion in charge of the stretch-flange forming where is a portion bearing flange-forming between the die and the pressing surface 51 of the blank holder 5. COPYRIGHT: (C)2008,JPO&INPIT