| 摘要 |
PURPOSE:To prevent the reduction in the lapping allowance of a can barrel and to perform the seam welding of the can barrel of high quality by specifying the relation between the peripheral length coming in touch with the can barrel of a drum shaped roller and the radius of the can barrel. CONSTITUTION:The drum shaped roller 1 group is arranged in plural sets in the direction of seam welding and the relation between the drum shaped roller 1 and can barrel 4 is as per the following. The peripheral length L surrounding the can barrel 4 by the drum shaped roller 1 and the outer diameter 2r of the can barrel are in the relation of 2pir<=L<=1.005X2pir. With the above, the shift of the lapping allowance accompanied by the temp. rise of the lapping allowance of the can barrel 4 is controlled by plural drum shaped roller 1 at the position to be seam-welded by the current flowed between the roller electrodes with moving the can barrel 4 along the guide rail. Consequently the reduction in the lapping allowance is prevented and the seam welding of the can barrel of high quality is enabled. |
