Plate-shaped fins of a heat exchanger each include, at circumferential portions thereof defining a notch in which a heat transfer tube having a flattened shape is disposed, fin collars formed by being raised from the circumferential portions. Each of the fin collars includes, in a position that faces a long axis side surface of the heat transfer tube, at least one reflare section bent in a direction opposite to the side surface. At least one of the reflare sections defining fin pitches between the adjoining plate-shaped fins is formed so that a reflare tip portion, which is a tip portion of the reflare section, is drawn apart from a contact side surface of the plate-shaped fin with which the reflare section comes into contact.

A method of manufacturing an evaporator of an air conditioner includes applying a coating agent to an outer surface of a heat transfer pipe to form a rust preventive film, wherein the coating agent includes a metal working oil and 0.1 to 1.0% by weight of a benzotriazole-based compound having a structure represented by the following formula (I)

##STR00001##

(wherein R1 to R4 each independently represent hydrogen or a methyl group, and R5 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms or (CH.sub.2).sub.nNR6-R7, n being an integer of 1 to 3, R6 and R7 being each independently an aliphatic hydrocarbon group having 1 to 18 carbon atoms), inserting the heat transfer pipe having the rust preventive film formed thereon into a hole of a heat transfer fin, and expanding the heat transfer pipe inserted the heat transfer fin.

A method of manufacturing an evaporator of an air conditioner includes applying a coating agent to an outer surface of a heat transfer pipe to form a rust preventive film, wherein the coating agent includes a metal working oil and 0.1 to 1.0% by weight of a benzotriazole-based compound having a structure represented by the following formula (I)

##STR00001##

(wherein R1 to R4 each independently represent hydrogen or a methyl group, and R5 represents an aliphatic hydrocarbon group having 1 to 18 carbon atoms or (CH.sub.2).sub.nNR6-R7, n being an integer of 1 to 3, R6 and R7 being each independently an aliphatic hydrocarbon group having 1 to 18 carbon atoms), inserting the heat transfer pipe having the rust preventive film formed thereon into a hole of a heat transfer fin, and expanding the heat transfer pipe inserted the heat transfer fin.

The present invention provides manufacturing method of a heat exchanger that, even if the position of a tube opening portion of a tube of a heat exchanger for which tube expansion is conducted, varies depending on the type of a heat exchanger, a mechanism adjusting the stop position of a flare plate as well as any complicated adjusting work therefor are not necessary and a heat exchanger in which flares in the same shape and in constant certain depth are formed at an opening portion of a tube of various kinds of heat exchangers having different total lengths in the longitudinal direction, and a device for a heat exchanger manufacturing method, and an air conditioner and/or outdoor unit thereof equipped with a heat exchanger manufactured using said manufacturing method.

A fin manufacturing apparatus includes an inter-row slit processing device having upper and lower blades with blade edges extending in a feed direction of a thin metal plate that serves as a material of a fin. The upper and lower blades are engaged with each other to form a perforated slit between rows on the fin. Each blade has a recess where the blade edge is partially recessed toward a ridge. Recess depth dimensions are smaller than a lapping amount of the blades when the blades are engaged with each other. At least one of the blades is slidable in a longitudinal direction of the blade edge to allow the recesses to be moved from overlapping positions to adjacent positions as viewed along a direction orthogonal to the longitudinal direction of the blade edges when the blades are engaged with each other over the lapping amount.

A fin manufacturing apparatus includes an inter-row slit processing device having upper and lower blades with blade edges extending in a feed direction of a thin metal plate that serves as a material of a fin. The upper and lower blades are engaged with each other to form a perforated slit between rows on the fin. Each blade has a recess where the blade edge is partially recessed toward a ridge. Recess depth dimensions are smaller than a lapping amount of the blades when the blades are engaged with each other. At least one of the blades is slidable in a longitudinal direction of the blade edge to allow the recesses to be moved from overlapping positions to adjacent positions as viewed along a direction orthogonal to the longitudinal direction of the blade edges when the blades are engaged with each other over the lapping amount.

A tube expander for heat exchanger coil units according to which a tubular expansion process is conducted. In one aspect, the tube expander includes a fixture, which includes a back unit and first and second door assemblies movably connected thereto. One or more heat exchanger coil units are adapted to be connected to each of the first and second door assemblies. In another aspect, the fixture is adjustable to accommodate different heat exchanger coil units. In yet another aspect, the tubular expansion process is not permitted when the first or second door assembly is closed and a sensor does not sense the presence of a latch bar.

The present invention discloses a novel micro-channel heat exchanger, comprising header pipes, a plurality of first flat pipes and fins, and further comprising a bending region formed by bending the header pipes, wherein second flat pipes and a bending assembly are provided in the bending region, the second flat pipes are connected between adjacent header pipes, the bending assembly is distributed between adjacent second flat pipes, and air is capable of passing through the bending assembly to circulate. On the premise that the performance of the heat exchanger is guaranteed, the present invention well solves the problem of fin deformation caused when the heat exchanger is bent along a length direction of the header pipes.

The present invention discloses a novel micro-channel heat exchanger, comprising header pipes, a plurality of first flat pipes and fins, and further comprising a bending region formed by bending the header pipes, wherein second flat pipes and a bending assembly are provided in the bending region, the second flat pipes are connected between adjacent header pipes, the bending assembly is distributed between adjacent second flat pipes, and air is capable of passing through the bending assembly to circulate. On the premise that the performance of the heat exchanger is guaranteed, the present invention well solves the problem of fin deformation caused when the heat exchanger is bent along a length direction of the header pipes.

A heat exchanger includes: flat tubes; a plate attached to the flat tubes; a medium tank configured to form a medium flow path by covering openings of flat tubes; and a reinforcing member to reinforce the openings. The reinforcing member includes a pair of leg portions and a connection portion that connects the leg portions. An insertion amount of the leg portions into the opening is larger than a sum of a gap between the connection portion and an inner surface and a length from the opening to a position corresponding to a brazed portion between the flat tube and the plate, or when a protruding portion protruding in a direction opposite an insertion direction is provided in the connection portion, larger than a sum of a gap between the protruding portion and the inner surface and a length from the opening to the position corresponding to the brazed portion.