Heat exchanger

A heat exchanger comprising:

• a core that includes a plurality of tubes, which are configured to conduct fluid;
• and
• two header tanks that are placed at two opposed longitudinal ends, respectively, of the plurality of tubes and are communicated with the plurality of tubes, wherein:
• each of the two header tanks includes:
• a core plate, to which the plurality of tubes is joined;
• a tank main body;
• at least one partition wall that is joined to the tank main body;
• at least two tank chambers that are formed by the core plate, the tank main body and the at least one partition wall;
• and
• a seal member;
• an inner surface of the core plate includes:
• an outer peripheral sealing surface that is configured into a loop and extends along an outer peripheral edge portion of the core plate and clamps the seal member in cooperation with an outer peripheral end portion of the tank main body;
• at least two tube connecting surfaces that extend in a corresponding plane and are located on an inner side of the outer peripheral sealing surface where the plurality of tubes is located, wherein each of the at least two tube connecting surfaces has at least one tube receiving hole, through each of which a corresponding one of the plurality of tubes is received;
• and
• at least one boundary portion sealing surface that extends in a corresponding plane, wherein each of the at least one boundary portion sealing surface is located between corresponding adjacent two of the at least two tube connecting surfaces to clamp the seal member in corporation with an end of each corresponding one of the at least one partition wall;
• the outer peripheral sealing surface includes:
• at least one primary section that extends in a corresponding plane;
• at least one secondary section that extends in a corresponding plane, wherein the corresponding plane of the at least one secondary section is generally parallel to the corresponding plane of the at least one primary section and is spaced from the corresponding plane of the at least one primary section in a direction perpendicular to the corresponding plane of the at least one primary section;
• and
• at least one transition section, each of which connects between a corresponding one of the at least one primary section and a corresponding one of the at least one secondary section and is tilted relative to the corresponding plane of the at least one primary section and the corresponding plane of the at least one secondary section;
• the corresponding plane of the at least one primary section is generally parallel to the corresponding plane of the at least two tube connecting surfaces and is placed on a side of the corresponding plane of the at least two tube connecting surfaces where an outside of the header tank is located;
• the corresponding plane of the at least one boundary portion sealing surface is displaced from the corresponding plane of the at least one primary section in a direction perpendicular to the corresponding plane of the at least one primary section within a range that does not exceed the corresponding plane of the at least two tube connecting surfaces on a side where an inside of the header tank is located;
• and
• the corresponding plane of the at least one secondary section is the same as the corresponding plane of the at least one boundary portion sealing surface.