| 摘要 |
PURPOSE:To enable a thermal conducting area of maximum degree to be supplied with a low cost by a method wherein a thin plate is bent in an alternative inner and outer V-shaped or V-shape with rounded corners, wound in a tubular form to seal aligning edges to make a finned tube, and a small cylindrical end part is formed at both end portions and this is inserted into a plug and brazed or welded thereto. CONSTITUTION:A thin plate is bent in an alternative inner or outer directions to form a V-shaped form. A part of a finned tube 1 wound in a cylindrical form is shown. In this condition, both end portions of the fins are kept open. End portions are sealed and a cylindrical part is formed in respect to segments (a), (b) and (c) of the fins. Each of points (d) and (e) is set on lines ab and cd to make a relation of bd=be, an end part of valley of the V-shape part is picked up with a picking tool to cause between bd and be to be closely contacted to each other in a proper width, a remaining ab and ce is crashed with a proper width to make a smooth part and this part is formed to have a part of the cylinder or a multi-sided cylinder 2. The cylinder part 2 at the end part of the formed finned tube is fitted into the spigot part of the plug 3, welded or brazed. The finned thermal conducting pipe is formed into a multi-layer type, thereby its multiplicity can be further increased.
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