Abstract: A heat exchanger comprising header pipes, flat tubes extending between the header pipes and fin units extending between the flat tubes is disclosed. The header pipes include a plurality of holes on one side thereof for accepting the flat tubes. On the opposite side of the header pipes is at least one slit in which a partition plate is inserted. During the formation of the header pipe, a pair of projections are formed on the ends of the slit. After the partition plate is inserted into the header pipe, the projections are bent until they engage the partition plate thereby fixedly securing the partition plate within the header pipe.

Abstract: A heat exchanger which includes a pair of substantially parallel header pipes. A plurality of substantially parallel tubes are disposed between the pair of header pipes. Each tube defines a pair of end portions which are connected to the pair of header pipes. Each of the pair of header pipes comprises a rectangular member which has a longitudinal opening formed along one side of the rectangular member. A connecting plate is installed in the opening. The connecting plate has a plurality of holes for receiving the end portions of the tubes therein to connect the tubes to each of the pair of header pipes. According to the above structure, a heat exchanger can be easily manufactured and inexpensively produced by reducing the cost for manufacturing the header pipes. The construction of the present heat exchanger reduces the occurrence of defects in the connection of tubes.

Abstract: The heat exchanger comprises a plurality of oval-shaped flat tubes for conducting refrigerant and a plurality of corrugated fins fixedly sandwiched between the flat tubes. First and second header pipes are fixedly and hermetically connected tot he flat tubes through openings formed on the header pipes and communicate with the interior of the flat tubes. The flat tubes include a pair of wedge-shaped projections at the opposite ends thereof, respectively. At least one pair of wedge-shaped projections engage with an interior surface of the header pipes adjacent to the openings when the flat tubes are received into the interior of the header pipes through the openings, thereby preventing relative sliding motion between the header pipes and the flat tubes through the openings. The wedge-shaped projection may be disposed on either the upper and lower flat surfaces or the curved side surfaces of the flat tubes.