Abstract: A serpentine-type aluminum heat exchanger comprising a serpentine-anfractuous flat tube of an aluminum alloy and a plurality of corrugated fin units made of an aluminum alloy having a high aluminum content of 99 wt. % or more, and joined to the flat tube by brazing metal coating layers fixed onto flat surfaces of parallel portions of the serpentine-anfractuous flat tube. The heat exchanger is produced by preparing the serpentine-anfractuous flat tube of an aluminum alloy, the corrugated fin units and foil plates of an aluminum alloy brazing filler metal, disposing the fin units in spaces between adjacent ones of parallel portions of the serpentine-anfractuous flat tube with foil plates being interposed between respective fin units and opposite parallel portions of the flat tube, and heating the flat tube, the fin units and foil plates in the assembled relation to the brazing temperature.

Abstract: In production of a serpentine-type aluminum heat exchanger having an aluminum flat tube with a plurality of fluid passageways and aluminum header pipes connected to opposite ends of the flat tube, flat sleeves with outer end flanges of aluminum alloy brazing filler metal are fitted on the opposite end portions of the flat tube while the end flanges being in contact with outer surfaces of the header pipes. The sleeves and end flanges are melted by heating so that the header pipes are brazed to the flat tube.

Abstract: In a corrugated fin unit assembled to a serpentine-anfractuous refrigerant pipe in a serpentine-type heat exchanger, each of generally parallel fin plate portions of the fin unit has a group of louvers parallel to the fin plate portion in the windward region and another group of louvers inclined downwardly in the leeward region, to thereby reduce air flow resistance of each fin unit without substantial reduction of heat exchange rate of the heat exchanger.

Abstract: A heat exchanger having a flat tube with a plurality of fluid passageways therein, header pipes connected to opposite ends of the flat tube and inlet and outlet tubes connected to the header pipes, respectively. The inlet and outlet tubes are inserted and fitted into the corresponding ones of the header pipes and formed with axial slits in the inserted end portions. The opposite ends of the flat tube extend into header pipes through axial slits in the outer surfaces thereof and are fitted into the axial slits of the inlet and outlet tubes inserted therein. Thus, the inlet tube and the outlet tube are reliably maintained in their desired orientation. The header pipes are made of aluminum brazing sheet and, therefore, are brazed to the aluminum flat tube and the inlet and outlet aluminum tubes.

Abstract: A serpentine-type aluminum heat exchanger comprising a serpentine-anfractuous flat tube of an aluminum alloy, a plurality of corrugated fin units made of an aluminum alloy having a high aluminum content of 99 wt. % or more, and brazing metal coating layers fixed onto entire flat surfaces of parallel portions of the serpentine-anfractuous flat tube and for joining the flat tube and the fin units, is produced by preparing the serpentine-anfractuous flat tube of an aluminum alloy, the corrugated fin units and U-shaped members of an aluminum alloy brazing filler metal, closely fitting the U-shaped members onto the parallel portions of the flat tube, disposing the fin units in spaces between adjacent U-shaped members fitted onto the parallel portions of the flat tube, and heating the flat tube, the fin units and U-shaped members in the assembled relation to the brazing temperature.

Abstract: Aluminum metal piece is dipped into a molten aluminum alloy brazing filler metal covered with a flux layer melted by heat of the molten filler metal, and thereafter is taken out therefrom. Thus, the aluminum metal piece is readily coated with a double coating film of the aluminum alloy brazing filler metal and the flux coating film.