A heat exchanger includes tube expansion portions provided respectively on a plurality of heat transfer tubes such that outer peripheral surfaces of the heat transfer tubes are respectively pressed against inner peripheral surfaces of a plurality of first holes provided in a side wall portion of a case, and a plurality of first concave surface portions provided in an outer surface of the tube expansion portion so that first gaps, into which brazing material of a first brazed portion advances, are formed between the outer surface of the tube expansion portion and the inner peripheral surface of the first hole. At least one of the plurality of first concave surface portions is positioned in an outside peripheral surface portion of the outer peripheral surface of the heat transfer tube. According to this configuration, the strength with which the heat transfer tubes are attached to the case can be increased while simplifying a manufacturing operation and reducing the manufacturing cost.

A heat exchanger for a vehicle includes a heat exchanger core. The heat exchanger core is configured to exchange heat between fluids. The heat exchanger further includes a header. The header is in fluid communication with the heat exchanger. A bracket is coupled to the header by a cold forming process.

A refrigerant pipe is provided to be capable of preventing a change in a length by which the refrigerant pipe is inserted after the refrigerant pipe is inserted. The refrigerant pipe includes a heat-exchanger-side pipe having a pipe component insertion flare formed at an end portion of the heat-exchanger-side pipe and at least one protrusion formed on an inner peripheral portion of the pipe component insertion flare, and a pipe component having a smaller outer diameter than an inner diameter of the pipe component insertion flare. A height of the at least one protrusion is greater than a dimension of a clearance defined on the basis of a difference between the inner diameter of the pipe component insertion flare and the outer diameter of the pipe component. The pipe component is inserted into the pipe component insertion flare, and the pipe component has a groove formed by the at least one protrusion.

A tube for a heat exchanger core bears a micro texture imprinted on an outer surface of the tube. The micro texture having depth of 0.01 mm to 0.03 mm and is thus hardly visible by a naked eye. When the tube is made of cladded metal strip material, the micro texture may have a depth that may be slightly greater than the thickness of the cladding. For folded tubes, an entire strip surface may be covered with the micro texture so that micro texture is present on the outer surface of tube and inside tube. Alternatively, the micro texture may be imprinted after forming the tube so that the micro texture is only present on the outer surface of the tube.

A device for heat transfer between a first fluid and a second fluid includes an assembly of tube elements for conducting the fluid and have a first, nondeformed region and a second, deformed region, disposed at an end of the tube element. A tube plate with passage apertures and a sealing element with passage apertures are provided. The sealing element is disposed between an outer surface of the second region of a tube element and an edge of a rim of the passage aperture of the tube plate. Tube elements are developed as flat tubes with flow channels. Flow channels are separated from one another by an internal structure element. A system and a method for the manufacture of the device are also provided.

A heat exchanger includes a tube expansion portion formed by expanding a heat transfer tube so that an outer peripheral surface of the heat transfer tube is pressed against an inner peripheral surface of a hole provided in a side wall portion of a case. The tube expansion portion includes first and second bulge portions positioned respectively on the inside and the outside of the side wall portion so as to sandwich the side wall portion in an axial length direction of the heat transfer tube and configured such that respective outer peripheral surfaces thereof partially bulge outward in a radial direction of the heat transfer tube, an end portion tip end of the heat transfer tube is positioned apart from the second bulge portion, and the end portion tip end and a part in the vicinity thereof are expanded so as to be included in a part of the tube expansion portion. Thus, effects such as improving the precision with which the side wall portion of the case, the heat transfer tube, and a connecting tube are fitted to each other can be achieved, and as a result, the respective parts can be brazed easily and appropriately.

A brazing sheet for flux-free brazing has an outermost surface brazing filler metal layer, consisting of an AlSi-based alloy containing 2 to 13% Si in mass %, and an intermediate brazing filler metal layer, consisting of an AlSiMg-based alloy containing 4 to 13% Si and 0.1 to 5.0% Mg in mass %, which are cladded on one or both sides of a core material. In the outermost surface brazing filler metal layer, the number of Si particles having a circle equivalent diameter of 1.75 m or more is 10% or more of the number having a circle equivalent diameter of 0.8 m or more, as observed in the direction of the surface layer. The intermediate brazing filler metal layer contains less than 3000 per 10000 m.sup.2 of Si particles having a circle equivalent diameter of 0.25 m or more, as observed in a cross section of the brazing filler metal layer.

A liquid to refrigerant heat exchanger includes an enclosed coolant volume that is at least partially defined by a plastic housing and by a metal closure plate. The metal closure plate can be part of a brazed assembly containing a continuous refrigerant flow path. The refrigerant flow path is disposed within the coolant volume, where heat can be transferred between the refrigerant within the refrigerant flow path and the liquid within the coolant volume. The plastic housing can at least partially surround the refrigerant flow path to at least partially bound a liquid flow path along a portion of the coolant volume. An inlet diffuser and an outlet diffuser can be mounted to the housing to direct the liquid through the housing. The plastic housing is sealingly joined to the closure plate along an outer periphery of the closure plate.

Manufacturing a heat exchanger by brazing of multiple heat transfer pipes, multiple fins, and headers. The multiple heat transfer pipes joined to each fin with the heat transfer pipes each being inserted into cutout recessed portions as cutouts of side portions of the fins on one side. The headers each joined to both end portions of each heat transfer pipe to couple the multiple heat transfer pipes and having internal spaces for collecting or distributing fluid flowing in the multiple heat transfer pipes. A protruding length Tf of each fin from a corresponding one of the heat transfer pipes and a distance Th from each heat transfer pipe to an outer surface of a corresponding one of the headers on the same side as a protrusion are substantially equal to each other.

A first connection portion is located on one side of a predetermined flow path member in a plane direction. The predetermined flow path member and another flow path member are bonded by brazing at the first connection portion. A second connection portion is located on the other side of the predetermined flow path member. The predetermined flow path member and another flow path member are bonded by brazing at the second connection portion. A brazing material layer extends over the predetermined flow path member, the first connection portion, and the second connection portion. A hilling portion is a portion of the predetermined flow path member. The hilling portion is curved to protrude toward a side on which the blazing material layer is provided. The hilling portion extends along a direction in which the first connection portion or the second connection portion extends.