| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a spiral tube, a spiral tube manufacturing device, and a manufacturing method, enabling reduction in plate thickness.SOLUTION: A spiral tube 1 is an air-conditioning duct whose cross section is cylindrical. A round tube part 11 whose axial core is straight is a tube part through which air (fluid) is made to flow straight by distance L1. The distance L1 is set to a desired/arbitrary length according to a construction site where the spiral tube is fitted. Side edges adjoining each other with a band material wound in spiral are connected at an engaging part 13, thus, a tube part whose axial core is straight is formed, and a plurality of protruding reinforcing ribs 12 extending in circumferential direction is formed at the round tube part.</p> |
