| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a heat exchanger in which any deformation of a mandrel occurs even if a heat transfer tube is expanded even when the diameter of the heat transfer tube is made to be smaller, and the adhesiveness of the heat transfer tube to a heat radiation fin is improved. Ž<P>SOLUTION: A tool to be used for tube expansion includes a first tool 41 having a truncated conical shape with a mandrel 43 being joined with its head part, and a second tool 42 having a cylindrical part and a plurality of outwardly openable tube-abutting members provided on a lower end of the cylindrical part. In a tube expansion step, the first tool 41 and the second tool 42 are inserted from a tube hole on one end side of the heat transfer tube 3 in advance in a separate manner from each other, and the mandrel 43 is once pulled upwardly at a tube terminating part on the other end side of the heat transfer tube 3. Then, the first tool 41 is inserted in the second tool 42, and the tube-abutting members of the second tool 42 are outwardly opened. By further pulling up the mandrel 43 in this condition, the heat transfer tube 3 is gradually expanded to integrally fix the heat transfer tube 3 to the heat radiation fin 2. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
|
