| 摘要 |
PURPOSE:To manufacture easily a titled heat transmitting tubes having a good heat exchange efficiency, by forming a fold on the inside circumferential part of a band plate for a fin in advance by a forming roll, when the band plate is wound around the circumference of a tube. CONSTITUTION:To a substrate 1, a guide plate 6 having a circular arc part which coincides with a part of the circumference of its tube insert-through hole 4 is attached by clamping and a band plate 11 is inserted into a recessed gap 5 through a path formed by a groove 3. Subsequently, the plate 11 is wound around the circumference of a tube 10 held by a chuck 12 through the hole 4, the start end of the plate 11 drawn out to the front of the plate 6 is clamp-held by the chuck 12, and the chuck 12 is rotated. As a result, when the plate 11 is wound around the outside of the tube 10 and drawn out to the front of the plate 6, the plate 1 is moved backward along a guide rod 17. At this state, the plate 11 is inserted through forming rolls 19a-19c rotating along the circumference of the axis crossing the advance of the plate 11 of the final end part of the path 3. In this way, a fold is formed on the plate 11 before it is wound around, and the inside circumferential surface of the plate 11 becomes apt to contract, therefore, the plate 11 is wound easily. |
