| 摘要 |
A heat exchanger, wherein a paste-like brazing filler metal (315) is applied to recessed parts (314) formed in the outer surface of a core tube (31) beforehand, a tube (32) is placed on the recessed parts, and the tube is brazed by a heating furnace. The brazing filler metal (315) molten by heating securely flows into the recessed parts (314) and cooled for fixing. Since the recessed parts (314) formed in the outer surface of the core tube (31) is securely filled with the brazing filler metal (33), a poor contact between the core tube (31) and the tube (32) can be eliminated. Also, even if the wall thickness of projected parts (313) is reduced in a projection processing step, the wall of the projected parts can be reinforced since the recessed parts (314) formed in the outer surface of the core tube (31) is filled with the brazing filler metal (33). Thus, a reduction in the strength of the projected parts (313) can be avoided. |
