To provide a method for manufacturing a tube, by which it is possible to easily obtain a tube having a sufficiently long folded-back tube part.
In manufacturing a tube 2 comprising a main tube part 10 and a folded-back tube part 11 folded back inwardly from the tip end of the main tube part and which adheres closely to an inner circumferential surface, which is part of the main tube part, wherein a double tube part 13 is configured by the folded-back tube part 11 and a part 12 of the main tube part 10 to which the folded-back tube part 11 adheres closely, the following steps are sequentially conducted: a first step of forming a curl part 31 by curling the tip end of a tube material 30 having the same diameter as that of the main tube part 10 toward the inside in the radial direction; a second step of forming a curl extension part 46 linked to the curl part 31 by pushing the curl part 31 toward the inside in the axial direction of the tube material 30 and by pulling part of the tube material 30 into the inside of the tube 2; and a third step of forming the folded-back tube part 11 by causing the curl extension part 46 and the curl part 31 to adhere closely to the inner surface of the tube material 30 while expanding the curl extension part 46 and the curl part 31 in diameter into a cylindrical shape.
OGOSHI KATSUNORI
USUI KAZUNARI
| JP2005046880A | 2005-02-24 | |||
| JP2009050888A | 2009-03-12 | |||
| JPH1058053A | 1998-03-03 | |||
| JP2007175761A | 2007-07-12 | |||
| JP2000061539A | 2000-02-29 |
Kazuaki Niki
Nude Shima Shinji