| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a metal can body by which a square cylinder type can body having a proper shape is efficiently manufactured even when a metal sheet which is thin in the sheet thickness is used for a base stock.SOLUTION: In the method of manufacturing the square cylinder type can body A, a cylindrical body a of a metal sheet is used as a material to be formed with an outer die 4 which has a corner-shaped working surface and also the tip part of the working surface is constituted into a circular-arcuate shape and an inner die 3 which has a circular-arcuate working surface at its tip, corner parts are formed by sandwiching the cylindrical body part which becomes the corner parts of a square cylinder and also side wall parts are formed by pressing the cylindrical body part which become the side wall parts of the square cylinder with the outer die 4. The can body is formed with the outer die 4 and the inner die 3, provided that the open angle θ of the working surface 40 of the outer die is taken as less than 90° and the open angle θ(°) of the working surface 40 of the outer die, the radius R (mm) of curvature in the tip portion of the working surface 40 of the outer die, the radius r (mm) of curvature of the working surface 30 of the inner die, the thickness t (mm) of the metal sheet and the yield strength σ(N/mm) of the metal sheet satisfy a predetermined relationship. |
