METHOD AND DEVICE FOR REDUCING CAN BODY IN DIAMETER

PROBLEM TO BE SOLVED: To prevent the buckling of a can body during forming by a reduction die, to perform large diametral reduction and to increase a tilting angle at the reduction working section. SOLUTION: A fluid pressure holding tool 13 having an elastic film is inserted into the can body and a fluid is made to flow in the fluid pressure holding tool 13 to expand the elastic film during the reduction operation. Then, a pressing force is applied to the can body inner wall of the reduction part to hold the can body against the forming pressure. The fluid pressure holding tool 13 is supported by a support 14 reaching the can bottom inner face and an axial loading applied to the fluid pressure holding tool 13 during the reduction operation, is transmitted to a can supporting table 5 via the support 14 to perform a large diametral reduction without being restricted by the buckling strength of the can body. The fluid is supplied to the space in the lower part of the can of the expanded fluid pressure holding tool 13 to prevent the deformation of the fluid pressure holding tool 13 in the axial direction due to forming pressure. COPYRIGHT: (C)2003,JPO