Aluminum heat exchanger and manufacturing method thereof

Abstract

A sheet material for the tube 10 includes: a core material 10 b ; and a sacrifical corrosion material 10 c clad on one face of the core material 10 b which becomes an outside of the tube 10 . A sheet material for the fin is a bare aluminum material on which a brazing filler metal is not clad. A mixture composition 10 e , in which powder of a brazing filler metal and flux are mixed with each other, is coated on the outside of the tube 10 . The tube 10 and the fin are brazed to each other with this mixture composition 10 e . Even after the completion of brazing, the sacrifical corrosion material 10 c remains on the outside of the tube 10.

1 . An aluminum heat exchanger in which a tube ( 10 ) composed of a sheet material is brazed to a fin ( 12 ) composed of a sheet material, 
 the sheet material for the tube ( 10 ) including a core material ( 10   b ) and also including a sacrifical corrosion material ( 10   c ) clad on one face of the core material ( 10   b ) which becomes an outside of the tube ( 10 ), wherein    the sheet material for the fin ( 12 ) is a bare aluminum material on which a brazing filler metal is not clad,    the tube ( 10 ) and the fin ( 12 ) are brazed to each other with powder of brazing filler metal, and    the sacrifical corrosion material ( 10   c ) remains on the outside of the tube ( 10 ) even after the completion of brazing.    
   
   
       2 . An aluminum heat exchanger according to  claim 1 , wherein the tube ( 10 ) and the fin ( 12 ) are brazed to each other when a mixture composite ( 10   e ), in which the powder of brazing filler metal and fluoride flux are mixed with each other, is coated on a surface of the sacrifical corrosion material ( 10   c ) on the sheet material for the tube ( 10 ).  
   
   
       3 . An aluminum heat exchanger according to  claim 1 , wherein the brazing filler metal powder is Si powder.  
   
   
       4 . An aluminum heat exchanger according to  claim 1 , wherein the brazing filler metal powder is mixture powder in which Si powder and Al powder are mixed with each other.  
   
   
       5 . An aluminum heat exchanger according to  claim 1 , wherein a brazing filler metal ( 10   d ) of Al—Si is clad on the other face of the core material ( 10   b ) of the sheet material for the tube ( 10 ) which becomes an inside of the tube ( 10 ), and 
 a joining face ( 10   a ) of the sheet material for the tube ( 10 ) is brazed by the brazing filler metal ( 10   d ) of Al—Si.    
   
   
       6 . An aluminum heat exchanger according to  claim 1 , wherein a joining face ( 10   a ) of the sheet material for the tube ( 10 ) is brazed when a mixture composite, in which the brazing filler metal powder and flux of fluoride are mixed with each other, is coated on the other side of the core material ( 10   b ) of the sheet material of the tube ( 10 ) which becomes an inside of the tube ( 10 ).  
   
   
       7 . An aluminum heat exchanger according to  claim 1  having an inner fin ( 13 ) arranged in the tube ( 10 ), wherein 
 the inner fin ( 13 ) is composed of a sheet material having a core material ( 10   b ) and a brazing filler metal ( 13   b ,  13   c ) clad on the core material ( 10   b ),    a joining face ( 10   a ) of the tube ( 10 ) is brazed by the brazing filler metal ( 13   b ,  13   c ) of the inner fin ( 13 ).    
   
   
       8 . An aluminum heat exchanger according to  claim 1 , wherein thickness of a residual layer of the sacrifical corrosion material ( 10   c ) after the completion of brazing is not less than 0.015 mm.  
   
   
       9 . A heat exchanger comprising: a plurality of tubes ( 30 ) having an inner passage in which a heat exchange medium is circulated; and members ( 65 ) to be joined which are attached to outsides of the tubes, 
 each tube including: a first core material portion ( 35 ) in which a plurality of protruded and recessed portions ( 37 ,  41 ) are formed; and a second core material portion ( 45 ) which composes an inner passage ( 33 ) together with the first core material portion in which a plurality of protruded and recessed portions ( 47 ,  51 ) are formed, wherein    the first core material portion and the second core material portion are brazed to each other with an inside brazing filler metal layer ( 43 ,  53 ) which is interposed between an inside protruded portion ( 41 ) of the first core material portion and an inside protruded portion ( 51 ) of the second core material portion,    a sacrifical corrosion layer ( 55 ) is clad on the outside of the first core material portion, an outside brazing filler metal layer ( 57 ) is clad and coated on the sacrifical corrosion layer ( 55   a ) of an outside protruded portion ( 37 ), a sacrifical corrosion layer ( 61 ) is clad on an outside of the second core material portion, and an outside brazing filler metal layer ( 63 ) is coated on the sacrifical corrosion layer ( 61   a ) of the outside protruded portion ( 47 ), and    the members ( 65 ) to be joined are respectively brazed to the outside protruded portion of the first core material portion and the outside protruded portion of the second core material portion with the outside brazing filler metal layer.    
   
   
       10 . A heat exchanger according to  claim 9 , wherein the inside brazing filler metal layer is coated on an inside of the inside protruded portion of the first core material portion and/or an inside of the inside protruded portion of the second core material portion.  
   
   
       11 . A heat exchanger according to  claim 9 , wherein the inside brazing filler metal layer is clad on the entire inside of the first core material portion and/or the entire inside of the second core material portion.  
   
   
       12 . A heat exchanger according to  claim 11 , wherein the inside brazing filler metal layer and the outside brazing filler metal layer respectively contain brazing filler metal powder and flux.  
   
   
       13 . A heat exchanger according to  claim 9 , wherein a plurality of protruded and recessed portions of the first core material portion and a plurality of protruded and recessed portions of the second core material portion are respectively composed of a plurality of protruded portions and a plurality of recessed grooves, and the protruded portions are opposed to each other to form the inside passage.  
   
   
       14 . A heat exchanger according to  claim 9 , wherein a plurality of protruded and recessed portions of the first core material portion and a plurality of protruded and recessed portions of the second core material portion are respectively composed of a plurality of protrusions and hollows, and a portion of the protrusion of the first core material portion and a portion of the protrusion of the second core material portion are communicated with each other so that the inside passage can be formed.  
   
   
       15 . A heat exchanger according to  claim 9 , wherein the first core material portion and the second core material portion are respectively formed into different bodies and put on each other.  
   
   
       16 . A heat exchanger according to  claim 9 , wherein the first core material portion and the second core material portion are formed when one core material is bent, and the first core material portion and the second core material portion are integrated with each other into one body.  
   
   
       17 . A heat exchanger according to  claim 9 , wherein the member to be joined is a corrugated fin.  
   
   
       18 . A heat exchanger according to  claim 9 , wherein the wall thickness of the first core material portion and the second core material portion is 0.1 to 0.2 mm, and the wall thickness of the member to be joined is 0.03 to 0.07 mm.  
   
   
       19 . A method of manufacturing a heat exchanger, 
 the heat exchanger including: a plurality of tubes ( 30 ) having an inner passage in which a heat exchange medium is circulated; and members ( 65 ) to be joined which are brazed to the outsides of the tubes,    the method of manufacturing the heat exchanger comprising:    a protruded and recessed portion forming step of forming a large number of protruded and recessed portions ( 37 ,  41 ,  47 ,  51 ) in the first core material portion ( 35 ), on the outside of which a sacrifical corrosion layer ( 55 ) is clad and, in the second core material portion ( 45 ), on the outside of which a sacrifical corrosion layer ( 61 ) is clad;    a coating step of coating an outside brazing filler metal layer ( 57 ,  63 ) on a sacrifical corrosion layer ( 55   a ) of the outside protruded portion ( 37 ) of the first core material portion and on a sacrifical corrosion layer ( 61   a ) of the outside protruded portion ( 47 ) of the second core material portion; and    a brazing step in which the first core material portion and the second core material portion are brazed to each other with an inside brazing filler metal layer ( 43 ,  53 ) which is interposed between an inside protruded portion ( 41 ) of the first core material portion and an inside protruded portion ( 51 ) of the second core material portion, and members ( 65 ) to be joined are brazed to an outside protruded portion ( 41 ) of the first core material portion and an outside protruded portion ( 51 ) of the second core material portion with the outside brazing filler metal layer.    
   
   
       20 . A method of manufacturing a heat exchanger according to  claim 19 , wherein the inside brazing filler metal layer is clad on the inside of the first core material portion and the inside of the second core material portion before the protruded and recessed portion forming step.  
   
   
       21 . A method of manufacturing a heat exchanger according to  claim 19 , wherein the inside brazing filler metal layer is coated on the inside of the inside protruded portion of the first core material portion and the inside of the inside protruded portion of the second core material portion in the coating step.  
   
   
       22 . A method of manufacturing a heat exchanger according to  claim 19 , wherein the outside brazing filler metal layer is coated with a rotating roller in the coating step.  
   
   
       23 . A method of manufacturing a heat exchanger according to  claim 19 , wherein the brazing filler metal layer is not provided on the fin which is a member to be joined.  
   
   
       24 . A heat exchanger comprising: a tube, in the inner passage of which a heat exchange medium is circulated; and a member to be joined which is joined to the outside of the tube by means of brazing, wherein 
 a wall of the tube is composed of a metallic sheet on which a plurality of protruded and recessed portions are formed,    the inner passage of the tube is formed when top portions of the inside protruded portions of the metallic sheet, which are opposed to each other, are joined to each other by means of brazing and edge portions of the metallic sheet are joined to each other by means of brazing,    the metallic sheet including:    a core material;    a sacrifical corrosion layer which is clad on the core material so that the sacrifical corrosion layer can be located outside the tube;    an inside brazing filler metal provided at the top of the inside protruded portion of the metallic sheet; and    an outside brazing filler metal coated only on the top portion of the outside protruded portion of the metallic sheet, wherein    the tube and the member to be joined are brazed to each other by the outside brazing filler metal.    
   
   
       25 . A heat exchanger according to  claim 24 , wherein the member to be joined is a corrugated fin formed out of a sheet material.  
   
   
       26 . A heat exchanger according to  claim 24 , wherein the tube is composed in such a manner that two metallic sheets are put on each other and edge portions of two pairs of the two metallic sheets are joined to each other by means of brazing.  
   
   
       27 . A heat exchanger according to  claim 24 , wherein the tube is composed in such a manner that one metallic sheet is bent and both edges portions of the metallic sheet are joined to each other by means of brazing.  
   
   
       28 . A heat exchanger according to  claim 24 , wherein the inside brazing filler metal is an inside brazing filler metal layer which is clad on the core material so that the inside brazing filler metal layer can cover the entire inside including the top portion of the inside protruded portion of the metallic sheet.  
   
   
       29 . A heat exchanger according to  claim 24 , wherein the inside brazing filler metal is an inside brazing filler metal layer which is coated only in the top portion of the inside protruded portion of the metallic sheet.