HEAT EXCHANGER

To provide a heat exchanger having a structure which can secure the dimension accuracy of a caulking seat face by easy cutting processing without the necessity for cutting processing using a fine processing tool to the caulking seat face.SOLUTION: A tank 400 has a crest/trough part 402 in which a crest part 407 and a trough part 408 are alternately formed in a peripheral direction by the fact that a part of an external peripheral face 406 of an opening part 401 corresponding to a caulking plate 300 is intermittently recessed in a peripheral direction of the opening part 401. The tank 400 has a groove part 403 which is formed at a duct 100 side of the crest/trough part 402 out of the external peripheral face 406 of the opening part 401 while being continuously arranged in the peripheral direction of the external peripheral face 406 of the opening part 401 by one round. The tank 400 has a caulking seat face 404 opposing the crest part 407 being a wall face of the duct 100 side out of a wall face constituting the groove part 403.SELECTED DRAWING: Figure 2 【課題】かしめ座面に対する微細な加工工具を用いた切削加工を必要とせずに、簡単な切削加工によってかしめ座面の寸法精度を確保することができる構造を備えた熱交換器を提供する。【解決手段】タンク４００は、かしめプレート３００に対応した開口部４０１の外周面４０６の一部が開口部４０１の周方向において断続的に凹むことで、山部４０７と谷部４０８とが周方向に交互に設けられた山谷部４０２を有する。タンク４００は、開口部４０１の外周面４０６のうち山谷部４０２のダクト１００側に形成され、開口部４０１の外周面４０６に周方向に一周連続して形成された溝部４０３を有する。タンク４００は、溝部４０３を構成する壁面のうちダクト１００側の壁面であると共に、山部４０７に対向するかしめ座面４０４を有する。【選択図】図２