| 摘要 |
[Problem] To provide a press-forming method whereby a product that has a heart-shaped or U-shaped horizontal cross section and is curved in the longitudinal direction can be formed with good dimensional precision. [Solution] A press-forming method whereby: first, both ends of a blank which is longer than the longitudinal length of the product to be formed are brought close to each other to a distance equal to the distance between the ends of the product; next, with the ends near to each other, sections of the blank corresponding to linear portions of the product are restrained while being press-formed toward a heart-shaped or U-shaped horizontal cross section, prior to a section of the blank corresponding to the curved portion of the product, thereby generating an excess, with respect to the length of the curved portion of the product, in the length of the section of the blank corresponding to the curved portion; next, with the excess length present, the section of the blank corresponding to the curved portion of the product is press-formed into a shape that is curved in the longitudinal direction and is formed with a heart-shaped or U-shaped horizontal cross section, thereby applying compressive stress, in the longitudinal direction, to the section of the blank corresponding to the curved portion of the product. |
