| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a novel roll forming method of parallel bending type, capable of improving a demerit wherein the center of a forming load in an FF forming method exists in a cluster forming part weak in a forming function, without impairing a merit of utilizing a roll in common in the FF forming method, capable of enhancing the forming function in a breakdown forming part, and capable of enhancing greatly formability over the whole plate material. <P>SOLUTION: Both side pinch points PP, PP for clamping a raw material 1 to be formed by a pair of left and right split type concave rolls 10, 11 on a lower side and a convex roll 12 on an upper side are set in a boundary part between a target forming area set in one area along a raw material width direction and an existing forming area, only the vicinities of both side pin points are pressed from a bending outside by the paired left and right split type concave rolls, without constraining the whole of the target forming area from the bending outside by the paired left and right split type concave rolls, the whole target forming area is thereby made to get along a surface of the convex roll on the upper side located in a bending inside, and a curvature of the convex roll surface is transferred to the target forming area. <P>COPYRIGHT: (C)2012,JPO&INPIT |
