Heat exchanger, and method for manufacturing heat exchanger

Abstract

A heat exchanger includes a first header having a first bent section and a first linear section extending from the first bent section, a second header having a second bent section bent in the same direction as the first bent section and opposed to the first bent section and a second linear section extending from the second bent section, first heat transfer pipes arranged along the first bent section and connecting the first bent section and the second bent section, and fins that each disposed between two adjacent first heat transfer pipes and that transfer heat from the first heat transfer pipes. At least one of the fins has a weak portions having a lower rigidity than the other portions of the fin, and being more readily deformed than the other portions in response to a change in the distance between the two adjacent first heat transfer pipes.

1 . A heat exchanger, comprising:
 a first header having
 a first bent section, and 
 a first linear section extending from the first bent section; 
   a second header having
 a second bent section bent in a same direction as the first bent section, and opposed to the first bent section, and 
 a second linear section extending from the second bent section; 
   first heat transfer pipes arranged along the first bent section and connecting the first bent section and the second bent section;   second heat transfer pipes arranged along the first linear section and connecting the first linear section and the second linear section; and   fins to transfer heat from the first heat transfer pipes and the second heat transfer pipes, the fins each being disposed between adjacent two of the first heat transfer pipes or between adjacent two of the second heat transfer pipes, wherein   at least one fin of the fins has a weak portion, the weak portion of each of the at least one fin having a lower rigidity than other portions of the fin, the weak portion being more readily deformed than the other portions in response to a change in a distance between the adjacent two of the first heat transfer pipes, and   at least one of the second heat transfer pipes is warped so as to be in a shape of a convex curve oriented toward the first bent section and the second bent section.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein
 each of the fins has a plate segment extending from one to the other of the adjacent two of the first heat transfer pipes, and   the weak portion is disposed in a part encompassing at least one of an end face of the plate segment that faces an inner side of bending of the first bent section, or an end face that faces an outer side of bending of the first bent section.   
     
     
         3 . The heat exchanger according to  claim 2 , wherein the weak portion has a fin-bent portion formed by bending the plate segment so as to protrude from one main surface of the plate segment. 
     
     
         4 . The heat exchanger according to  claim 3 , wherein the one main surface of the plate segment faces a gravity direction, and the fin-bent portion protrudes in the gravity direction. 
     
     
         5 . The heat exchanger according to  claim 2 , wherein the weak portion has a first notch cut out, toward a central part of the plate segment, from one of the end face of the plate segment that faces the inner side of bending of the first bent section, or the end face that faces the outer side of bending of the first bent section. 
     
     
         6 . The heat exchanger according to  claim 5 , wherein each of the first notches has any of a triangular, rectangular, or semicircular shape when viewed in a direction orthogonal to main surfaces of the plate segment. 
     
     
         7 . The heat exchanger according to  claim 5 , wherein the weak portion has
 the first notch, and   a second notch cut out, toward the central part of the plate segment, from the other of the end face of the plate segment that faces the inner side of bending of the first bent section, or the end face that faces the outer side of bending of the first bent section.   
     
     
         8 . The heat exchanger according to  claim 2 , wherein the weak portion has a first thin portion at a position adjoining one of the end face of the plate segment that faces the inner side of bending of the first bent section, or the end face that faces the outer side of bending of the first bent section, the first thin portion having a smaller thickness than other portions of the plate segment. 
     
     
         9 . The heat exchanger according to  claim 8 , wherein the first thin portion has, when viewed in a direction orthogonal to main surfaces of the plate segment,
 a triangular shape having
 a vertex located adjacent to a central part of the plate segment, and 
 an opposite side of the vertex located at the end face of the plate segment, or 
   a semicircular shape having
 a center located adjacent to the end face of the plate segment, and 
 a convex arc oriented toward the central part of the plate segment. 
   
     
     
         10 . The heat exchanger according to  claim 8 , wherein the weak portion has
 the first thin portion, and   a second thin portion at a position adjoining the other of the end face of the plate segment that faces the inner side of bending of the first bent section, or the end face that faces the outer side of bending of the first bent section, the second thin portion having a smaller thickness than other portions of the plate segment.   
     
     
         11 . The heat exchanger according to  claim 1 , wherein
 each of the fins has a plate segment having a shape of corrugation between one and another of the adjacent two of the first heat transfer pipes, and   the weak portion is disposed in the plate segment and has warped portions making a width of mountain portions or valley portions of the corrugation larger than a half of a wavelength of the corrugation.   
     
     
         12 . The heat exchanger according to  claim 1 , wherein the fins protrude further than the first heat transfer pipes, toward at least one of an inner side or an outer side of bending of the first bent section. 
     
     
         13 . The heat exchanger according to  claim 1 , wherein all of the fins have the weak portion. 
     
     
         14 . The heat exchanger according to  claim 1 , wherein the fins include
 first fins each having the weak portion, and   second fins each not having the weak portion.   
     
     
         15 . The heat exchanger according to  claim 14 , wherein the first fins and the second fins are alternately arranged in gaps between the first heat transfer pipes, the gaps being aligned in an arrangement direction of the first heat transfer pipes. 
     
     
         16 . The heat exchanger according to  claim 14 , wherein
 the second fins are arranged in gaps between the first heat transfer pipes, the gaps being aligned in an arrangement direction of the first heat transfer pipes, the second fins constituting fin arrays successively aligned in the arrangement direction of the first heat transfer pipes, each of the fin arrays including two or more of the second fins successively aligned in the arrangement direction, and   the first fins are each disposed between adjacent two of the fin arrays.   
     
     
         17 . (canceled) 
     
     
         18 . A method of fabricating a heat exchanger, the method comprising:
 building a semifinished heat exchanger including
 a first header having a first linear pipe section, 
 a second header having a second linear pipe section in parallel to the first linear pipe section, 
 heat transfer pipes arranged along the first linear pipe section and connecting the first linear pipe section and the second linear pipe section, and 
 fins to transfer heat from the heat transfer pipes, the fins each being disposed between adjacent two of the heat transfer pipes, at least one fin of the fins having a weak portion, the weak portion of each of the at least one fin having a lower rigidity than other portions of the fin, the weak portion being more readily deformed than the other portions in response to a change in a distance between the adjacent two of the heat transfer pipes; and 
   producing a heat exchanger including the first header having a first bent section and a first linear section extending from the first bent section and the second header having a second bent section bent in a same direction as the first bent section and opposed to the first bent section and a second linear section extending from the second bent section, the heat exchanger being produced by bending, in a same direction, the first linear pipe section of the first header included in the semifinished heat exchanger and the second linear pipe section of the second header included in the semifinished heat exchanger, wherein   in the producing of the heat exchanger, the bending of the first linear pipe section of the first header and the second linear pipe section of the second header changes the distance between the adjacent two of the heat transfer pipes and deforms the weak portion,   the heat transfer pipes include heat transfer pipes connecting the first linear section and the second linear section, and   at least one of the heat transfer pipes connecting the first linear section and the second linear section is warped so as to be in a shape of a convex curve oriented toward the first bent section and the second bent section.