Heat transfer member and method for manufacturing same

Abstract

A heat transfer member for a heat exchanger, is press-formed of a metallic thin sheet material into a prescribed shape by means of molds of a press forming device so that the heat transfer member has on at least one portion thereof a heat transfer face having opposite surfaces, which are to be brought into contact with heat exchange fluids, respectively. The heat transfer face comprises at least one set of irregularity patterns arranged in a row. Each of the at least one set of irregularity pattern units comprises (i) a central pattern portion having a plurality of recesses or projections provided with a prescribed pitch, (ii) a pair of heat exchanging irregularity pattern portions provided on opposite sides of the central pattern portion so as to be symmetrical with respect to the central pattern portion and (iii) at least one boundary pattern portion provided on at least one of respective outer sides of the pair of heat exchanging irregularity pattern portions so as to be adjacent to the respective outer sides thereof. The boundary pattern portion has a prescribed width and a plurality of recesses or projections provided with a same pitch as the plurality of recesses or projections of the central pattern portion so as to be in parallel therewith.

What is claimed is:  
     
         1 . A heat transfer member for a heat exchanger, which is press-formed of a metallic thin sheet material into a prescribed shape by means of molds of a press forming device so that said heat transfer member has on at least one portion thereof a heat transfer face having opposite surfaces, which are to be brought into contact with heat exchange fluids, respectively, 
 wherein: 
 said heat transfer face comprises at least one set of irregularity patterns arranged in a row, each of said at least one set of irregularity pattern units comprising (i) a central pattern portion having a plurality of recesses or projections provided with a prescribed pitch, (ii) a pair of heat exchanging irregularity pattern portions provided on opposite sides of said central pattern portion so as to be symmetrical with respect to said central pattern portion and (iii) at least one boundary pattern portion provided on at least one of respective outer sides of said pair of heat exchanging irregularity pattern portions so as to be adjacent to the respective outer sides thereof, said at least one boundary pattern portions having a prescribed width and a plurality of recesses or projections provided with a same pitch as said plurality of recesses or projections of said central pattern portion so as to be in parallel therewith.  
   
     
     
         2 . A heat transfer member for a heat exchanger, which is press-formed of a metallic thin sheet material into a prescribed shape by means of molds of a press forming device so that said heat transfer member has on at least one portion thereof a heat transfer face having opposite surfaces, which are to be brought into contact with heat exchange fluids, respectively, 
 wherein: 
 said heat transfer face comprises at least one set of irregularity patterns arranged in a row, each of said at least one set of irregularity pattern units comprising (i) a central pattern portion having a plurality of recesses or projections provided with a prescribed pitch, said central portion having two pairs of opposite sides, (ii) a pair of heat exchanging irregularity pattern portions provided on one of said two pairs of opposite sides of said central pattern portion so as to be symmetrical with respect to said central pattern portion, said pair of heat exchanging irregularity pattern portions and said central pattern forming a pair of opposite connection sides extending along an other of said two pairs of opposite sides of said central pattern portion, and (iii) at least one boundary pattern portion provided on at least one of said pair of opposite connection sides, said at least one boundary pattern portion having a prescribed width and a plurality of recesses or projections with a prescribed pitch so as to be perpendicular to said plurality of recesses or projections of said central pattern portion.  
   
     
     
         3 . The heat transfer member as claimed in  claim 2 , wherein: 
 said boundary pattern portion continues in a form of grooves or projections in a direction perpendicular to a direction of said plurality of recesses or projections thereof so as to form a plurality of rows of irregularities, providing a smooth wave-shaped cross section.    
     
     
         4 . The heat transfer member as claimed in  claim 1  or  2 , wherein: 
 said central pattern portion or said boundary pattern portion continues in a form of grooves or projections in a direction of said plurality of recesses or projections thereof so as to form a plurality of rows of irregularities, providing a smooth wave-shaped cross section.  
 
     
     
         5 . A method for manufacturing a heat transfer member, comprising the step of: 
 subjecting a material to be worked, which is made of a metallic thin sheet, to a press forming utilizing a press-forming device, while feeding said material to be worked in a single feeding direction, to form a heat transfer member for a heat exchanger, said heat transfer member having a prescribed shape, said heat transfer member having on at least one portion thereof a heat transfer face that has opposite surfaces, which are to be come into contact with heat exchange fluids, respectively,    wherein: 
 said press-forming device comprises a main mold for forming the heat transfer face, said main mold having prescribed patterns of irregularity, which are placed in prescribed front and rear zones in the feeding direction of the material to be worked so as to be symmetrical to each other with respect to a central position between said front and rear zones and be in an equal positional relationship relative to said central position in a perpendicular direction to said feeding direction of said material to be worked;  
 said material to be worked is press-formed by means of said main mold of said press-forming device so that at least one set of press-formed portions are placed without forming a gap therebetween, thereby forming the heat transfer member.  
   
     
     
         6 . The method as claimed in  claim 5 , wherein: 
 the patterns of irregularity of the main mold of said press-forming device, which are placed in the front and rear zones in the feeding direction of the material to be worked, are identical to each other; and    of the press-formed portions of the material to be worked, which have been formed utilizing said press-forming device, the press-formed portion having the pattern of irregularity, which is placed on a side of the rear zone in said feeding direction, is subjected to a re-pressing step utilizing the pattern of irregularity, which is placed on a side of the front zone in said feeding direction in said main mold, while intermittently feeding said material to be worked by a prescribed length, thereby forming the sets of press-formed portions on the material to be worked.