A method and system for manufacturing a hairpin tube. The method includes cutting a coil of tube to provide a plurality of lengths of tubes, and bending each length of tube to form a plurality of hairpin tubes. A lubricant is then atomized with an injector nozzle, and injected into at least one open end of each hairpin tube. After lubricating the hairpin tubes, the legs of each hairpin tube are expanded.

A method is disclosed for producing a heat exchanger, in particular for a motor vehicle, a method whereby fluid circulation tubes (3) are inserted into through holes in heat exchange fins (4) and the fluid circulation tubes (3) are subjected to expansion in such a way as to expand a contour (22) of the tubes (3) to ensure contact with the fins (4) at the through holes and, additionally, for at least one of the tubes (3), to deform a concave portion (24) of the contour (22) of the tube or tubes (3), in such a way as to correspondingly deform the through holes. A device for implementing the method and an exchanger obtained by the method are also disclosed.

A heat transfer tube fixing apparatus of a heat transfer tube expansion apparatus has grasping sections and a moving section. The grasping sections grasp one axial direction end sections of a plurality of heat transfer tubes in a state where the heat transfer tubes are inserted in a plurality of heat transfer fins. The moving section switches between a first state of covering the surroundings of the grasping sections and a second state of not covering the surroundings of the grasping sections by moving in the axial direction of the heat transfer tubes. The grasping sections fix the heat transfer tubes so as not to move in the axial direction and the heat transfer fins and the heat transfer tubes are fixed by the heat transfer tubes expanding in a state where the moving section is in the first state.

A heat exchanger and a method of manufacturing the same are provided. With the method, a tube may be inserted into a through hole formed in at least one fin coated with a filler metal, and the tube and a fin collar of the at least one fin may be joined through the filler metal by a brazing processing. A flange may not be formed on or at a top of the at least one fin collar, which protrudes vertically from a central longitudinal plane of the at least one fin. The tube may be made of aluminum (Al), and an interval between an outer circumferential surface of the tube and an inner circumferential surface of the fin collar of the at least one fin may be approximately 0.1 mm or less. Accordingly, contact resistance occurring when fabricating a fin-tube heat exchanger using a mechanical tube expansion method may be reduced, and heat transfer performance of the heat exchanger may be improved because grooves formed within the tube may not be deformed.