| 摘要 |
PURPOSE:To prevent local deterioration of strength of the vessel by performing a push in operation to the side face of the vessel in the stage of performing further plastic working for the cylindrical metallic vessel manufactured by plastic working a sheet. CONSTITUTION:A vertically movable die 14 is provided on the cylindrical metallic vessel 9 manufactured by plastically working the sheet and interlocking with it, a vertically or horizontally movable die 15 is disposed. A cap 10 and an elastic sealing material 11 are disposed on the upper opening part of the vessel 9, the die 14 is taken down to start the plastic deforming of the upper end part. In this case, a die 15 is interlocked with the die 14 to push the side face of the vessel 9 downward or inward. By this method, expanding outward the groove part 12 of the vessel 9 is prevented, the groove part 12 is deformed inward to free. Therefore, the residual tensile stress of the grove part 12 is changed to zero or a compressive stress and the local deterioration of the vessel strength at that part is prevented. |
