To effectively prevent the generation of the deformation of cross-section shape or wrinkles following to bending of a metal and to easily and inexpensively produce a bending article having the high value of goods by fitting a restricting dummy, bending the long size metal in this fitting state and then removing the restricting dummy.
A mandrel 3 is inserted in a body part 10, respective fin like projection parts 11a, 11b are fitted with restricting dummies 2A, 2A providing proper fitting grooves 21, after bending them in this state, the restricting dummies 2A, 2A are removed. Therefore, each restricting dummy 2A is bent as one body with the metal 1A, however, the fin like projection parts 11a, 11b clamped with the grooves 21 are restricted and not allowed to change the shape except the bending direction, on the result, the circular arc like bending article without generating incline or wrinkles on the fin like projection parts 11a, 11b is easily obtained. Further, the restricting dummies 2A, 2A are easily taken out from the metal 1A.
SHIODA SHUNTA
TOCHIGI MASAHARU
