Abstract: An object to provide a press-forming method that can efficiently suppress springback and easily specify a position where a springback reduction effect by rigidity improvement is large, and the press-forming method used in producing a press-formed product having a predetermined shape by press-forming a sheet material, the method including: a first process that repeatedly performs a springback analysis, while changing a position to be restricted, to specify a position where a springback reduction effect by rigidity improvement is large; a second process that performs a rigidity improvement measure on a position of the sheet material corresponding to the position of the formed-product model specified in the first process; and a third process that produces the press-formed product by press-forming the sheet material on which the rigidity improvement measure has been performed.

Abstract: A method for manufacturing a press-formed product includes a blanking step of blanking from a sheet-shaped material into a shape in which an excess material portion is added to the contour outline of a developed shape of the press-formed product, a first pressing step of folding the excess material portion to form straight sides into an intermediate formed product with a bent flange portion, a second pressing step of performing press forming including bulging in which the bulging portion is provided on the intermediate formed product, and a trimming step of trimming the excess material portion. A blank material includes excess material portion to be folded to form straight sides circumscribed around or spaced apart from a contour outline of a developed shape of the press-formed product, and an intermediate formed product includes excess material portion including a bent flange portion folded to form straight sides.

Abstract: To suppress springback of the press-formed product, in improving rigidity of a press-formed product having a low rigidity shape produced by press-forming a sheet material by a rigidity adding shape to suppress springback at a time when the press-formed product is removed from a die, the rigidity adding shape is arranged to extend in a direction of crossing a displacement contour indicating a state of springback in an initial shape prior to an arrangement of the rigidity adding shape of the press-formed product.

Abstract: There is a need to suppress falling or rising of an end of a press-formed product and twisting of the press-formed product due to springback to suppress a shape defect of the press-formed product due to the springback and, in designing a shape of a press-formed product produced by press-forming a sheet material, a curvature radius (R1) of a concave curved portion and a curvature radius (R2) of a convex curved portion of a concave and convex curved shape of an additional shape arranged on the press-formed product where the concave curved portion and the convex curved portion are continuous are set to be the same.

Abstract: An object to provide a press-forming method that can efficiently suppress springback and easily specify a position where a springback reduction effect by rigidity improvement is large, and the press-forming method used in producing a press-formed product having a predetermined shape by press-forming a sheet material, the method including: a first process that repeatedly performs a springback analysis, while changing a position to be restricted, to specify a position where a springback reduction effect by rigidity improvement is large; a second process that performs a rigidity improvement measure on a position of the sheet material corresponding to the position of the formed-product model specified in the first process; and a third process that produces the press-formed product by press-forming the sheet material on which the rigidity improvement measure has been performed.