| 摘要 |
PURPOSE:To easily form and attach a helical fin, by fixedly attach a fin material to a tube or rod while setting a wave form to the material by allowing a necessary movement ot the peripheral part of a squeezing roll. CONSTITUTION:A tube 1 is moved in the axial direction while being rotated at a prescribed speed in the direction of coiling of a fin material 2a. On the other hand, the material 2a, coiled around a core shaft 13, is smoothly transferred to be coiled around the tube 1 by rotating the core shaft 13 in the direction of uncoiling of the material 2a. Then a high frequency welding is performed while pressing the contacting position between the material 2a and the tube 1 by a squeezing roll 9. |
