Heat exchanger and method of manufacturing the same

Abstract

A method for manufacturing a heat exchanger ( 1 ) includes joining an inner fin ( 3 ) to a hollow structure ( 20 ) formed from at least two clad plates ( 200 a, 200 b ) by heating and brazing a filler metal layer (B). Each clad plate has a core layer (A) composed of an aluminum alloy that contains Mg: 0.40-1.0 mass %. The filler metal layer is composed of an aluminum alloy that contains Si: 4.0-13.0 mass %, and further contains Li: 0.0040-0.10 mass %, Be: 0.0040-0.10 mass %, and/or Bi: 0.01-0.30 mass %. The inner fin is composed of an aluminum alloy that contains Si: 0.30-0.70 mass % and Mg: 0.35-0.80 mass %. A flux (F) that contains cesium (Cs) is applied along a contact part ( 201 ), and the vicinity thereof, of the at least two clad plates prior to the heating. A heat exchanger ( 1 ) may be manufactured according to this method.

We claim: 
     
         1 . A heat exchanger, comprising:
 a jacket comprising at least two plate materials joined together along at least one jacket junction, the plate materials being composed of an aluminum alloy and the at least one jacket junction being composed of an Al—Si alloy, wherein a surface configured to mount a heat-generating element is defined on an outer surface of the jacket, and a coolant passageway is defined in an interior of the jacket; and   an inner fin disposed in the coolant passageway, the inner fin being composed of an aluminum alloy and being joined to the jacket at a plurality of fin junctions, each fin junction being composed of an Al—Si alloy;   wherein:   the aluminum alloy of the at least two plate materials contains Mg: 0.40-1.0 mass %; and   cesium is present on an inner surface of the jacket only from the jacket junction to the inner fin.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein the aluminum alloy of the at least two plate materials further contains one, two or more elements selected from the group consisting of Mn: 0.050-1.3 mass %, Si: 1.0 mass % or less, Fe: 1.0 mass % or less, Cu: 0.90 mass % or less, Zn: 6.5 mass % or less, Ti: 0.20 mass % or less, and Zr: 0.50 mass % or less. 
     
     
         3 . The heat exchanger according to  claim 1 , wherein the aluminum alloy of the inner fin contains Si: 0.30-0.70 mass % and Mg: 0.35-0.80 mass %. 
     
     
         4 . The heat exchanger according to  claim 3 , wherein the aluminum alloy of the inner fin further contains one, two or more elements selected from the group consisting of Mn: 0.050-1.3 mass %, Fe: 1.0 mass % or less, Cu: 0.90 mass % or less, Zn: 6.5 mass % or less, Ti: 0.20 mass % or less, and Zr: 0.50 mass % or less. 
     
     
         5 . The heat exchanger according to  claim 1 , wherein a core layer of the at least two plate materials contains Mg: 0.40-0.80 mass %. 
     
     
         6 . The heat exchanger according to  claim 1 , wherein the inner fin is joined to the jacket at both ends of the inner fin in a fin width direction of the inner fin. 
     
     
         7 . The heat exchanger according to  claim 1 , wherein the Al—Si alloy of the fin junctions and the jacket junction contains Si: 4.0-13.0 mass %. 
     
     
         8 . The heat exchanger according to  claim 7 , wherein the Al—Si alloy of the fin junctions and the jacket junction further contains one, two or three elements selected from the group consisting of Li: 0.0040-0.10 mass %, Be: 0.0040-0.10 mass %, and Bi: 0.01-0.30 mass %. 
     
     
         9 . The heat exchanger according to  claim 1 , wherein the Al—Si alloy of the fin junctions and the jacket junction contains Si: 7.5-10.0 mass %. 
     
     
         10 . The heat exchanger according to  claim 9 , wherein the Al—Si alloy of the fin junctions and the jacket junction further contains one, two or three elements selected from the group consisting of Li: 0.010-0.050 mass %, Be: 0.010-0.050 mass %, and Bi: 0.010-0.10 mass %. 
     
     
         11 . The heat exchanger according to  claim 10 , wherein a core layer of the at least two plate materials contains Mg: 0.40-0.80 mass %. 
     
     
         12 . The heat exchanger according to  claim 11 , wherein the aluminum alloy of the at least two plate materials further contains one, two or more elements selected from the group consisting of Mn: 0.050-1.3 mass %, Si: 1.0 mass % or less, Fe: 1.0 mass % or less, Cu: 0.90 mass % or less, Zn: 6.5 mass % or less, Ti: 0.20 mass % or less, and Zr: 0.50 mass % or less. 
     
     
         13 . The heat exchanger according to  claim 12 , wherein the aluminum alloy of the inner fin contains Si: 0.30-0.70 mass % and Mg: 0.35-0.80 mass %. 
     
     
         14 . The heat exchanger according to  claim 13 , wherein the aluminum alloy of the inner fin further contains one, two or more elements selected from the group consisting of Mn: 0.050-1.3 mass %, Fe: 1.0 mass % or less, Cu: 0.90 mass % or less, Zn: 6.5 mass % or less, Ti: 0.20 mass % or less, and Zr: 0.50 mass % or less. 
     
     
         15 . A method for manufacturing the heat exchanger of  claim 1 , comprising:
 assembling an object to be processed by disposing the inner fin within an interior of a hollow structure formed from at least two clad plates that each have a filler metal layer disposed on a side thereof that faces the interior of the hollow structure and contacts the inner fin; and   heating the object to be processed in an inert-gas atmosphere to melt the filler metal layer and join the hollow structure to the inner fin and to join the at least two clad plates to each other along a contact part, thereby forming the jacket;   wherein:   the at least two clad plates each comprise the filler metal layer clad onto a core layer,   the core layer is composed of an aluminum alloy that contains Mg: 0.40-1.0 mass %;   the filler metal layer is composed of an aluminum alloy that contains Si: 4.0-13.0 mass %, and further contains one, two or three elements selected from the group consisting of Li: 0.0040-0.10 mass %, Be: 0.0040-0.10 mass %, and Bi: 0.01-0.30 mass %, the filler metal layer (B) containing less than 0.10 mass % Mg;   the inner fin is composed of an aluminum alloy that contains Si: 0.30-0.70 mass % and Mg: 0.35-0.80 mass %; and   a flux that contains cesium is applied to the contact part, and to the vicinity thereof, of the at least two clad plates prior to the brazing, wherein the flux melts during the heating step to break up oxide films on surfaces of the at least two clad plates along the contact part.   
     
     
         16 . The method according to  claim 15 , wherein the amount of the flux applied to the contact part is 0.05-1.0 g per meter of the contact part. 
     
     
         17 . The method according to  claim 16 , wherein the flux contains 13-58 mass % of Cs. 
     
     
         18 . The method according to  claim 17 , wherein the flux that contains Cs is applied only to the contact part, and the vicinity thereof, and no flux is applied to any surface area of the hollow structure that contacts the inner fin. 
     
     
         19 . A method for manufacturing a heat exchanger, comprising:
 assembling an object to be processed by disposing an inner fin within an interior of a hollow structure formed from at least two clad plates that each have a filler metal layer disposed on a side thereof that faces the interior of the hollow structure and contacts the inner fin; and   heating the object to be processed in an inert-gas atmosphere to melt the filler metal layer and join the hollow structure to the inner fin and to join the at least two clad plates to each other along a contact part;   wherein:   the at least two clad plates each comprise the filler metal layer clad onto a core layer,   the core layer is composed of an aluminum alloy that contains Mg: 0.40-1.0 mass %;   the filler metal layer is composed of an aluminum alloy that contains Si: 4.0-13.0 mass %, and further contains one, two or three elements selected from the group consisting of Li: 0.0040-0.10 mass %, Be: 0.0040-0.10 mass %, and Bi: 0.01-0.30 mass %, the filler metal layer containing less than 0.10 mass % Mg;   the inner fin is composed of an aluminum alloy that contains Si: 0.30-0.70 mass % and Mg: 0.35-0.80 mass %; and   a flux that contains cesium is applied to the contact part, and to the vicinity thereof, of the at least two clad plates prior to the brazing, wherein the flux melts during the heating step to break up oxide films on surfaces of the at least two clad plates along the contact part.   
     
     
         20 . The method according to  claim 19 , wherein:
 the core layer further contains one, two or more elements selected from the group consisting of Mn: 0.050-1.3 mass %, Si: 1.0 mass % or less, Fe: 1.0 mass % or less, Cu: 0.90 mass % or less, Zn: 6.5 mass % or less, Ti: 0.20 mass % or less, and Zr: 0.50 mass % or less;   the inner fin further contains one, two or more elements selected from the group consisting of Mn: 0.050-1.3 mass %, Fe: 1.0 mass % or less, Cu: 0.90 mass % or less, Zn: 6.5 mass % or less, Ti: 0.20 mass % or less, and Zr: 0.50 mass % or less;   the filler metal layer (B) has an Mg content of 0.05 mass % or less;   the amount of the flux applied to the contact part is 0.05-1.0 g per meter of the contact part; and   the flux contains 13-58 mass % of Cs.