| 摘要 |
<p>A heat exchanger (1) includes a header (2,3) having tube insertion holes (22) and heat transfer tubes (6), wherein each of said heat transfer tubes (6) has an end portion inserted into a corresponding tube insertion hole (19,20). A burr (21) is formed on a wall of the header (2,3) around each tube insertion hole (19,20) to extend in a direction toward an interior of the header (2,3). The burr (21) has a bent tip portion (21a,21b) formed by bending at least a part of a tip portion of the burr inwardly. A tip of the end portion (6a) of each heat transfer tube (6) inserted into a corresponding tube insertion hole (19,20) contacts with the bent tip portion (21a,21b) of the burr (21). The bent tip portion (21a,21b) of the burr seals a gap formed between an outer surface of the inserted end portion of the tube and an inner surface of the burr when the header and the tubes are assembled and brazed, thereby preventing leakage of a heat exchange fluid through such a gap. The insertion depth of the tube (6) is reduced by the bent tip portion (21a,21b) of the burr, thereby decreasing pressure loss in the header. <IMAGE></p> |
