Abstract: A core unit of a heat exchanger is composed of a plurality of parallel flat tubes, a plurality of corrugated fins, a support member disposed between two of the corrugated fins and an electric heater disposed inside the support member. The support member has a pair of parallel plates bonded to the corrugated fins at the summits of corrugation of the corrugated fins. The electric heater is composed of a heating element and an insulation member inserted between the heating element and the parallel plates.

Abstract: An air conditioning apparatus includes a heating heat exchanger for heating air blown toward a passenger compartment using hot water as a heating source. A plurality of electric heating members are formed integrally with the heating heat exchanger, and electric power supplied to the electric heating members is controlled according a temperature of the hot water. Therefore, a number of the electric heating members to be operated is finely controlled according to the temperature of water flowing through the heating heat exchanger. Further, when a water temperature of the heating heat exchanger is lower than a predetermined temperature (e.g., 35.degree. C.), a water valve is closed to interrupt the flow of water to the heating heat exchanger, and a blower is operated. Therefore, a quantity of heat transmitted from the electric heating members to the water in the heating heat exchanger can be greatly decreased.

Abstract: An electric heat emitter is disposed at a predetermined position in a heat exchanging core portion having a plurality of tubes and corrugated fins. The electric heat emitter includes a positive electrode plate and a negative electrode plate which are insulated from the heat exchanging core portion. An electric wiring cover made of resin having a positive electrode wiring member and a negative electrode wiring member is attached to an outlet tank of the heat exchanger. The positive and negative electrode plates connect to the positive and negative electrode wiring members respectively. Thus, the electric current is supplied to the electric heat emitter through an electric circuit insulated from the heat exchanger, thereby preventing metal parts of the heat exchanger from being electrically corroded.

Abstract: An aluminum heat exchanger includes laminated aluminum tubes and corrugated fins, a core portion receiving respective ends of tubes into sheet metals members, and iron or stainless steel inserts having high strength receiving U-shaped folded pieces of the sheet metal members contacting the corrugated fins at the outermost portion of the core portion. The tubes and the corrugated fins are held and pressed from both sides of the core portion by the inserts and the corrugated fins are protected from coming apart during a brazing operation.

Abstract: A heat-exchanging core portion includes a plurality of tubes arranged in parallel and a plurality of fin members disposed between a pair of adjacent tubes. While an electric heat emitting unit is constructed by supporting a heat emitting body including a heat emitting element inside a frame through a fin member. The electric heat emitting unit is installed into a space, which is defined in the heat-exchanging core portion, having a predetermined distance after the heat-exchanging core portion is assembled and integrally brazed while defining the space.

Abstract: A heat exchanger includes a tank and a base plate, and each of the tank and the base plate is formed in a box shape having a U-shaped cross-section. The tank is connected to the base plate to close an end portion of an opening side of the tank using the base plate. Protrusion portions are provided inside a folded portion of the base plate in a lateral direction to be opposite to connection portions of first and second folded portions of the tank. Further, ribs are provided in the folded portion of the base plate in the lateral direction to increase stiffness of the base plate in a longitudinal direction thereof. Thus, connection portions of the tank and the base plate can be securely brazed.

Abstract: A heat exchanger reduces a production of scrap portions and does not use a claw bending process at a time of forming a tank and a base plate. Each of the tank and the base plate is formed in a box shape having a U-shaped cross-section. The tank is joined to the base plate to close an end portion of an opening side of the tank using the base plate. A tube is inserted into a hole made at the base plate and fixed thereat in such a manner that the tube communicates with an inside of the tank. Each of the tank and the base plate is formed by folding an unfolded metal plate in which the box shape having the U-shaped cross section is in an unfolded state and joining a folded portion of the unfolded metal plate by brazing. According to the above configuration, the tank and the base plate can be structured by folding unfolded plates and by connecting the folded portions.

Abstract: A heater core of a construction which is easy to produce by a molding process, while providing a desired sealing effect with respect to its casing. The heater core 20 is formed by a pair of tanks 28 and a heat exchanging section 27 arranged between the tanks 28. The heat exchanging section 27 is formed by a pair of top and bottom support plates 33 and stack of heat exchanging tubes 31 and fins 32 arranged alternately. The top and bottom supporting plates 33 have a width with is equal to the width of tanks 28, so that end surfaces of the support plates 33 are located on the same plane with respect to outer surfaces of the tank 28 in the direction of the flow of the air contacting with the heat exchanging section 27.

Abstract: According to the present invention, in a corrugated fin type heat exchanger including a core portion having a plurality of flat tubes disposed in parallel relation with regard to a flow direction of air and at least one corrugated fin disposed between each pair of the flat tubes, a height of a flow space within the flat tube is in a range of 0.6-1.2 mm, a height of the corrugated fin is in a range of 3-6 mm, and a ratio (St/W.times.D) of the cross-sectional area (W.times.D) expressed by an overall width dimension (W) and a thickness dimension (D) of the core portion to a total cross-sectional flow passage area (St) of the plurality of flat tubes is set to a range of 0.07-0.24 according to the height of the flow space of the flat tube and the height of the corrugated fin.

Abstract: A corrugated fin type heater core includes an inlet tank, an outlet tank, tubes and a corrugated fin. The corrugated fin has a cross section elongated in a direction parallel to the direction in which air flows to a region where heat exchange takes place. The corrugated fin is brazed to the tubes and has a multiplicity of louvers angled in the direction in which the air is introduced. The corrugated fin has a height Hf within the range of between 2.5 mm and 6.0 mm.

Abstract: A large value of the radius R of the curved portion 110 of a corrugated fin 101 allows fillet portion 104 to have a large length along the length of the pipe 102 for decreasing the heat resistance between the pipe 102 and the fin 101, which makes the length of the louver portions 103 small. Contrary to this, a small value of the radius R of the curved portion 110 of a corrugated fin 101 allows louver portions 103 to have a large length, which is formed on the straight portion of the fin for increasing the heat transfer efficiency from the louver, which causes, however, the length of the fillet to be shortened. Best matching was obtained for decreasing the heat resistance and increasing the heat transfer efficiency when the radius of the curved portion is selected in a range between 0.14 mm to 0.37 mm.