| 摘要 |
PURPOSE:To eliminate the need of a softening treatment by annealing of a fin material, by continuously cutting off a bent outer-peripheral part i.e. a work- hardening part of a fin material, with the aid of a cutting-off device provided to a prescribed position, in a drawing process where the sheared off fin material is spirally wound around the outer periphery of a steel pipe. CONSTITUTION:In a drawing process where a fin material 1, left as it is after being sheared off, is continuously wound around a steel pipe 8, a metal cutter 9 is arranged at a prescribed position, situated on the outside of bending when the material 1 is wound around the pipe 8. The cutter 9 is rotated through a shaft 10 to continuously cut off a work-hardening part 11 locating at the outer- end part of the bent material 1. In addition, rolls 12 for preventing the material 1 from deflecting laterally and vertically and supporting rolls 13 are respectively provided near the cutter 9 for the purpose of performing the cutting work by the cutter 9 uniformly. |
