Patent ID: 7303003

Claim:
A heat exchanger comprising: a heat exchange core section configured such that heat exchange tube groups are arranged in a plurality of rows in an air flow direction, each heat exchange tube group comprising a plurality of heat exchange tubes arranged at predetermined intervals, a first header which is disposed on a first-end side of the heat exchange tubes and to which the heat exchange tubes of at least one heat exchange tube group are connected, a second header which is disposed on the first-end side of the heat exchange tubes and upstream of the first header with respect to the air flow direction and to which the heat exchange tubes of the remaining heat exchange tube groups are connected, a third header which is disposed on a second-end side of the heat exchange tubes and to which the heat exchange tubes connected to the first header are connected, and a fourth header which is disposed on the second-end side of the heat exchange tubes and to which the heat exchange tubes connected to the second header are connected, wherein the headers each comprise a hollow header body having opposite ends opened, and caps each having a flat wall portion and fixed to the corresponding opposite ends of the header body, the flat wall portions closing the corresponding opposite end openings of the header body, a reinforcement projection portion projecting toward the interior of the header is formed on the flat wall portion of at least one of the caps, a refrigerant inlet is formed in the cap which closes a first end opening of the header body of the first header, a refrigerant outlet is formed in the cap which closes an end opening, which corresponds to the first end opening of the header body of the first header, of the header body of the second header, the third header and the fourth header communicate with each other, the reinforcement projection portion is formed on the flat wall portion of the cap which closes the end opening opposite the refrigerant inlet of the header body of the first header, partition means extending horizontally divides the interior of the second header into a first space and a second space, the heat exchange tubes are connected to the second header in such a manner as to communicate with the first space, refrigerant passage holes are formed in the partition means, the second space of the second header communicates with the refrigerant outlet, a recess portion to be fitted into the first space and a recess portion to be fitted into the second space are formed on the two caps which close the corresponding opposite end openings of the header body of the second header, and bottom walls of the recess portions serve as the flat wall portions which close the corresponding opposite end openings of the header body.