| 摘要 |
PURPOSE:To shorten a manufacturing line and to obtain a long-sized, high- strength, small tube by reducing a butt-welded tube by using a sinking roll and a push-through die in manufacturing a small tube by reducing a tubular strip after welding the butting part of a metallic strip formed into a tubular shape. CONSTITUTION:In manufacturing a small tube e.g. a tube used for covering communication cables; a metallic strip is cut into a desired width by a slitter 2 while running it, and the butting part 7 of strip 1 is welded while forming the strip 1 into a tubular shape by vertical and horizontal forming rolls 4, 5, 3. A tube 6 obtained in this way, is reduced at a >=5% working rate by five-stage sinking rolls 8, and is push-fed to a die 9 installed in the vicinity of the outlet of rolls 8 to successively reduce it at a <=20% reduction rate of area by utilizing the driving force of rolls 8. The tube 6 is drawn by a drawing die, at need to enhance the strength of small tube. |
