| 摘要 |
PURPOSE:To efficiently execute a working to a sheet material without generating a buckling, and to obtain a product having a stable quality executing the rolling plural times, while pressing a forming roller against the end part of the sheet material, while moving relatively the forming roller and the plate material. CONSTITUTION:The upper end part of the sheet material 5 is heated by a burner 8, a first annular groove 10 is allowed to coincide with the upper end part of the plate material 5 by sliding a forming roller 9, and the upper end part is worked to a thick wall to some extent by moving a movable body 7. Subsequently, the forming roller 9 is moved so that a second annular groove 11 conforms with a working part, and the part is further worked to a thick wall. According to this method, the working can be executed efficiently. |
