METHOD FOR MANUFACTURING CURVED COMPONENT HAVING POLYGONAL CLOSED CROSS SECTIONAL STRUCTURE AND CURVED COMPONENT HAVING POLYGONAL CLOSED CROSS SECTIONAL STRUCTURE AND MANUFACTURED USING SAID METHOD

摘要

To provide a technique for press forming from a single metal sheet a curved component that has a polygonal closed cross sectional structure. [Solution] The present invention is characterized in that during the manufacturing of a component having a polygonal closed cross sectional structure that is curved along the longitudinal direction and has flange parts that extend along ridge lines located on the innermost side in the radial direction of the curved shape: a gutter shaped pre finish component that has a cross sectional shape when the component is cut and unfolded at the ridge lines located on the innermost side in which the ridge lines and flange parts that extend along the ridge lines are formed by the respective end parts of the component and has multiple ridge lines that correspond to the corner parts of the polygonal closed cross section of the component wherein the respective ridge lines corresponding to the respective corner parts have a curvature radius that is the same as or smaller than the curvature radius of the corresponding ridge lines of the component is press formed first; and the pre finish component is then pressed at any one or more positions of the multiple ridge lines thereof so as to be deformed inward in the direction of the cross section in order for the ridge lines and the flanges located on the innermost side to butt together.