METALLIC MEMBER HAVING HAT-SHAPED CROSS SECTION AND HAVING BENT PART IN PLANE IN LONGITUDINAL DIRECTION OF MEMBER

PROBLEM TO BE SOLVED: To provide a metallic member having a hat-shaped cross section, having a bent part in a plane in its longitudinal direction, and having a highly accurate three-dimensional shape and shape stability. SOLUTION: When forming a metallic member having a hat-shaped cross section and having a bent part in a plane in its longitudinal direction with a press using a punch and a die for example, the method reduces tensile stress, which is generated in forming the member, by forming, at the lower dead point of a punch, a fillet part that has a cross-sectional circumference shorter than the surrounding circumference. Thereby degradation of dimensional accuracy of the three-dimensional shape, which is caused by spring-back, twist, and the like, is prevented, so that shape stability is secured. COPYRIGHT: (C)2009,JPO&INPIT