To provide a method by which a shape of press-formed goods excellent in the accuracy of pres forming is obtained by a simple press-forming method without depending on empirical estimated generation of springback.
In a press-forming stage of a metallic sheet where the sheet reaches the final shape of press-formed goods through a plurality of press-forming stages, the accuracy of forming is improved by suppressing the springback after forming by performing press-forming with a die having a size which is smaller by at least 1 mm than the size by which the shape of the portion is specified about a portion where a tensile residual stress is generated and performing the press-forming with a die having a size which is larger by at least 1 mm than the size by which the shape of the portion is specified about the portion where compressive residual stress is generated. This method is applicable to a ridge line part and a vertical wall part.
COPYRIGHT: (C)2007,JPO&INPIT
Ogawa Misao
Takashi Miyagi
Tatsuo Watanuki