| 摘要 |
PURPOSE:To reinforce expanded thin parts and to improve seaming work of an end plate by fitting a cylindrical can drum having open upper and lower ends to the outside of radially and vertically divided expander type sectional dies and leaving at least a part of the can drum of an end side without expanding. CONSTITUTION:Sectional dies 2 are formed shorter than the length of the can drum so as not to expand upper and lower parts of the can drum 1. When the sectional dies 2 are opened radially by lowering a taper rod 4, can drum parts 1a retaining the original form are left in the upper and lower parts of the can drum 1. Accordingly, a remaining part of the can drum 1a is thick and has high tensile strength, and expanded thin middle parts of the cam drum are reinforced by the can drum 1a. In this case, the original form is left in the upper and lower parts of the can drum. However, reinforcing can be effected by either of upper or lower part. |
