| 摘要 |
PURPOSE:To make it possible to manufacture easily even an elongated heat transfer pipe attached with coiled fins by a method wherein a chain-like coiled fin unit is arranged around the heat transfer pipe in such a manner that a straight linear member is passed through the overlapped ends of the coiled fin unit. CONSTITUTION:The prefabricated coiled fin unit 13 is arranged about the heat transfer pipe 11 and is pressed against the pipe by applying a couple of forces in the direction of the arrows A as if to enbrace the pipe by use of a jig A comprised of a couple of opposing members 14. In this case, each of the coiled fine 12 expands to some degree so that both ends of the coiled fin unit 13 are overlapped each other as at 12' and 12'. Therefore, in the case of the instant invention, the straight linear member 16 is passed through the overlapped section of the coiled fins 12' when the unit 13 is arranged about the heat transfer pipe 11. As a consequence, all of the coiled fins 12 are brought into resilient contact with the outer periphery of the pipe 11. Further, it shouled be noted in this connection that the insertion of the linear member 16 into the overlapped section of the coiled fins 12' can be performed in a mechanical method. The linear material 16 thus inserted is then bent so as not to slip out of the fins 12' and is silver- brazed to the fins to thereby increase the strength of attachment thereof to the fins. |
