Production method for heat exchanger, heat exchanger, and air-conditioning device

Abstract

According to the present invention, a production method for a heat exchanger has: an intermediate product preparation step for producing an intermediate product that comprises a first header tube and a second header tube that are provided so as to face and a plurality of heat transfer tubes (200) that are connected to the first header tube and the second header tube; and a bending step for bending the first header tube and the second header tube of the intermediate product. A header virtual center plane (VP1) passes through the center in the header width direction of the first header tube and the second header tube and extends in the header tube length direction and the header facing direction. Both the first header tube and the second header tube of the intermediate product have an asymmetrically rigid structure at a bending part (20) that is to be bent, the asymmetrically rigid structure being such that the bending rigidity of a bending outside part (20a) that is to be positioned on the outside of the header virtual center plane (VP1) with respect to the direction of the radius of curvature is greater than the bending rigidity of a bending inside part (20b) that is to be positioned on the inside of the header virtual center plane (VP1) with respect to the direction of the radius of curvature.

Description

Heat exchanger manufacturing method, heat exchanger, and air conditioning device

[0001] The present disclosure relates to a method for manufacturing a heat exchanger, a heat exchanger, and an air conditioning device.

[0002] A known heat exchanger serving as an evaporator or condenser in a refrigeration cycle includes a first header pipe and a second header pipe arranged facing each other, and a plurality of heat transfer tubes arranged between the first and second header pipes. One end of each heat transfer tube is connected to the first header pipe, and the other end is connected to the second header pipe. The plurality of heat transfer tubes are aligned in the longitudinal direction of the first and second header pipes.

[0003] Patent Document 1 discloses a heat exchanger having a bent portion where a first header pipe and a second header pipe are bent in the longitudinal direction of the heat transfer tube. In this heat exchanger, the heat transfer tube has an outer tube and an inner column disposed inside the outer tube. The inner column divides the inside of the outer tube into multiple flow paths.

[0004] JP 2013-139971 A

[0005] The heat exchanger disclosed in Patent Document 1 can be obtained by a manufacturing method in which straight first and second header pipes, to which multiple heat transfer tubes are connected, are bent to form the bent portions. However, during the bending process, the inner columns may break inside the heat transfer tubes. This is because the bent portions of the first and second header pipes stretch, generating tensile stress in the inner columns of the heat transfer tubes that follow this stretching. If the inner columns break, the pressure resistance of the heat transfer tubes will decrease.

[0006] An object of the present disclosure is to provide a heat exchanger manufacturing method that is less likely to cause breakage in the inner columns of the heat transfer tubes when forming bends in the first header pipe and the second header pipe, a heat exchanger that can be obtained by the heat exchanger manufacturing method, and an air conditioning device equipped with the heat exchanger.

[0007] A heat exchanger manufacturing method according to the present disclosure includes an intermediate product preparation step and a bending step. In the intermediate product preparation step, an intermediate product is manufactured. The intermediate product includes a first header pipe and a second header pipe arranged facing each other, and a plurality of heat transfer tubes, each of which has one end connected to the first header pipe and the other end connected to the second header pipe. The plurality of heat transfer tubes are aligned in a header pipe length direction, which is the direction in which the first header pipe and the second header pipe extend. In the bending step, the first header pipe and the second header pipe of the intermediate product are bent to form bent portions in the first header pipe and the second header pipe as viewed in a header facing direction, which is the direction in which the first header pipe and the second header pipe face each other. Each heat transfer tube of the intermediate product includes a hollow, tubular outer tube extending in the header facing direction and at least one inner column dividing the interior of the outer tube into a plurality of flow paths. A header virtual center plane is defined for the first header pipe and the second header pipe of the intermediate product. The header imaginary center plane passes through the center of the first header pipe and the second header pipe in the header width direction perpendicular to the header pipe length direction and the header facing direction, and extends in the header pipe length direction and the header facing direction. Each of the first header pipe and the second header pipe of the intermediate product has, in a bending target portion that will become a bent portion through bending, an asymmetric rigidity structure in which the bending rigidity of an outer bend portion that is located outward from the header imaginary center plane in the direction of the radius of curvature of the bent portion is higher than the bending rigidity of an inner bend portion that is located inward from the header imaginary center plane in the direction of the radius of curvature.

[0008] According to the heat exchanger manufacturing method disclosed herein, the bending stiffness of the outer bending portion of each of the bending target portions of the first header pipe and the second header pipe of the intermediate product is made higher than the bending stiffness of the inner bending portion. Therefore, compared to when the bending stiffness of the outer bending portion and the inner bending portion are equal, the neutral plane of bending in the bending target portion during bending can be shifted outward in the direction of the radius of curvature from the virtual center plane of the header.

[0009] As a result, during bending, the maximum tensile stress acting on the inner column of the heat transfer tube is reduced. Therefore, when forming bent portions in the first header tube and the second header tube, breakage of the inner column of the heat transfer tube is unlikely to occur.

[0010] Conceptual diagram showing the configuration of the air conditioner according to Embodiment 1 Perspective view showing the configuration of the outdoor heat exchanger according to Embodiment 1 Conceptual diagram showing a cross section perpendicular to the header facing direction of the heat transfer tube according to Embodiment 1 Flowchart showing the method for manufacturing the outdoor heat exchanger according to Embodiment 1 Perspective view showing the configuration of the intermediate manufactured product according to Embodiment 1 Conceptual diagram for explaining the bending process according to Embodiment 1 Plan view showing the bending target portion of the header tube according to the comparative form Plan view showing the bending target portion of the header tube according to Embodiment 1 Perspective view showing the main part of the header tube according to Embodiment 1 Perspective view showing the main part of the header tube according to the modification of Embodiment 1 Perspective view showing the main part of the header tube according to Embodiment 2 Perspective view showing the main part of the header tube according to the modification of Embodiment 2 Perspective view showing the main part of the header tube according to another modification of Embodiment 2 Perspective view showing the main part of the header tube according to Embodiment 3 Perspective view showing the main part of the header tube according to the modification of Embodiment 3 Perspective view showing the main part of the second member according to the modification of Embodiment 3 Perspective view showing the main part of the header tube according to another modification of Embodiment 3 Plan view showing the bending target portion of the header tube according to Embodiment 4 Plan view showing the bending target portion of the header tube according to the modification of Embodiment 4 Conceptual diagram showing the interior of the outdoor unit housing according to Embodiment 5 Perspective view showing the main part of the header tube according to Embodiment 6 Plan view showing the layered member according to Embodiment 6 Cross-sectional view of the header tube according to Embodiment 6 at the position of the X-X line in FIG. 20A Cross-sectional view of the header tube according to Embodiment 6 at the position of the Y-Y line in FIG. 20A Plan view showing the main part of the header tube according to the modification of Embodiment 6 Cross-sectional view of the header tube according to the modification of Embodiment 6 at the position of the Z-Z line in FIG. 21A Plan view showing the intermediate layered member according to the modification of Embodiment 6

[0011] Hereinafter, referring to the drawings, the air conditioner according to the embodiment will be described. In the drawings, the same or corresponding parts are denoted by the same reference numerals.

[0012] [Embodiment 1] Fig. 1 shows the configuration of an air conditioner 600 according to this embodiment. The air conditioner 600 has a heating operation function for heating a room (not shown) to be air-conditioned, and a cooling operation function for cooling the room. In Fig. 1, solid arrows indicate the flow of refrigerant during heating operation. Dashed arrows indicate the flow of refrigerant during cooling operation.

[0013] The air conditioning system 600 includes a compressor 610 that compresses a refrigerant, an indoor heat exchanger 620 that functions as a condenser to condense the compressed refrigerant during heating operation, an expander 630 that expands the condensed refrigerant, and an outdoor heat exchanger 500 that functions as an evaporator to evaporate the expanded refrigerant during heating operation. The compressor 610, indoor heat exchanger 620, expander 630, and outdoor heat exchanger 500 form a refrigeration cycle.

[0014] The air conditioner 600 also has a four-way valve 640 that reverses the direction of refrigerant flow in the refrigeration cycle. Because the four-way valve 640 can reverse the direction of refrigerant flow, the indoor heat exchanger 620 also functions as an evaporator during cooling operation, and the outdoor heat exchanger 500 also functions as a condenser during cooling operation.

[0015] The air conditioner 600 also includes an indoor fan 650 that promotes heat exchange between the refrigerant in the indoor heat exchanger 620 and the air in the room to be air-conditioned (hereinafter referred to as "indoor air"). The indoor fan 650 creates an airflow of the indoor air that passes through the indoor heat exchanger 620.

[0016] The air conditioner 600 also includes an outdoor fan 660 that promotes heat exchange between the refrigerant in the outdoor heat exchanger 500 and outside air (hereinafter referred to as outside air). The outdoor fan 660 forms an airflow of outside air that passes through the outdoor heat exchanger 500.

[0017] In the air conditioning system 600 described above, the outdoor heat exchanger 500 is an example of a heat exchanger according to the present disclosure. The compressor 610, the indoor heat exchanger 620, the expander 630, and the four-way valve 640 are an example of a group of cooperating devices that, together with the outdoor heat exchanger 500, form a refrigeration cycle using a refrigerant.

[0018] The greatest feature of the air conditioner 600 according to this embodiment lies in the configuration and manufacturing method of the outdoor heat exchanger 500. Therefore, the outdoor heat exchanger 500 will be specifically described below.

[0019] As shown in FIG. 2 , the outdoor heat exchanger 500 includes a first header pipe 110A and a second header pipe 110B arranged facing each other, a plurality of heat transfer tubes 200 arranged between the first header pipe 110A and the second header pipe 110B, and a plurality of fins 300 held by the plurality of heat transfer tubes 200.

[0020] Hereinafter, the direction in which the first header pipe 110A and the second header pipe 110B face each other will be referred to as the “header facing direction.” The imaginary line representing the header facing direction is a straight line.

[0021] The first header pipe 110A and the second header pipe 110B extend parallel to each other. Hereinafter, the direction in which the first header pipe 110A and the second header pipe 110B extend, i.e., the length direction of each of the first header pipe 110A and the second header pipe 110B along their respective pipe paths, will be referred to as the "header pipe length direction."

[0022] In other words, the imaginary line representing the header pipe length direction overlaps the first header pipe 110A and the second header pipe 110B over their entire lengths. The first header pipe 110A and the second header pipe 110B are formed in a curved L-shape when viewed in the header-facing direction. Therefore, the imaginary line representing the header pipe length direction also has a curved L-shape when viewed in the header-facing direction.

[0023] One end 200a of each heat transfer tube 200 is connected to the first header pipe 110A, and the other end 200a is connected to the second header pipe 110B. A plurality of heat transfer tubes 200, each extending straight in the header facing direction, are lined up in the header pipe length direction. Fins 300 are arranged between adjacent heat transfer tubes 200 in the header pipe length direction.

[0024] In the present embodiment, of the first header pipe 110A and the second header pipe 110B, a first end piping 671 leading to the compressor 610 shown in Fig. 1 and a second end piping 672 leading to the expander 630 shown in Fig. 1 are connected to the first header pipe 110A. However, at least one of the first end piping 671 and the second end piping 672 may be connected to the second header pipe 110B.

[0025] The first header pipe 110A and the second header pipe 110B have the same structure, ignoring the details including the connection points of the first end pipe 671 and the second end pipe 672. Therefore, hereinafter, the first header pipe 110A and the second header pipe 110B may be collectively referred to as the "header pipes 110."

[0026] The header pipe 110 and each of the heat transfer pipes 200 are connected by inserting the end 200 a of each of the heat transfer pipes 200 facing the header into the header pipe 110 .

[0027] 3 shows a cross section of the heat transfer tubes 200 perpendicular to the header-facing direction at the position of the end 200a connected to the header tube 110. An insertion opening 10 is formed in the header tube 110 for each heat transfer tube 200, and the end 200a of the corresponding heat transfer tube 200 is inserted into the insertion opening 10. The outer surface of the end 200a of the heat transfer tube 200 is joined to the inner surface of the insertion opening 10 into which the end 200a is inserted.

[0028] The heat transfer tubes 200 and the header tube 110 are both made of metal. The outer surface of the end 200a of the heat transfer tube 200 and the inner surface of the insertion opening 10 of the header tube 110 are joined together by brazing, specifically.

[0029] Hereinafter, the direction perpendicular to the header facing direction and the header pipe length direction, that is, the direction representing the width of the header pipe 110, will be referred to as the "header width direction."

[0030] Each heat transfer tube 200 has a hollow, tubular outer tube 210 that extends straight in the direction facing the header, and a plurality of inner pillars 220 that partition the inside of the outer tube 210 .

[0031] The outer pipe 210 has a shape that is elongated in the header width direction when viewed in the header facing direction, specifically, a rounded rectangle shape that is elongated in the header width direction. The multiple inner posts 220 divide the interior of the outer pipe 210 into multiple flow paths 230 that are aligned in the header width direction.

[0032] The refrigerant flows through each of the flow paths 230. Specifically, the refrigerant flowing through each of the flow paths 230 joins together in the header pipe 110 shown in FIG. 2 , or the refrigerant flowing through the header pipe 110 is distributed to each of the flow paths 230.

[0033] 3 illustrates a configuration in which 20 flow paths 230 are defined by 19 inner pillars 220, but the number of inner pillars 220 is not limited. Two flow paths 230 may be defined by one inner pillar 220.

[0034] Returning to Fig. 2, a description will be given of the external shape of the outdoor heat exchanger 500. In the outdoor heat exchanger 500, each of the first header pipe 110A and the second header pipe 110B has a bent portion 21 that is bent when viewed in the header facing direction.

[0035] Each of the first header pipe 110A and the second header pipe 110B also has a straight portion 22 that extends straight when viewed in the header facing direction. The straight portion 22 is continuous with both ends of the bent portion 21 in the header pipe length direction.

[0036] A method for manufacturing an outdoor heat exchanger according to this embodiment will be described below with reference to Fig. 4. This is one example of a method for manufacturing a heat exchanger according to the present disclosure.

[0037] The above-described bent portion 21 of the header pipe 110 is formed by bending (step S12). This step S12 is an example of a bending process according to the present disclosure.

[0038] Therefore, before step S12, an intermediate product to be subjected to bending is produced (step S11). This step S11 is an example of an intermediate product preparation step according to the present disclosure.

[0039] Fig. 5 shows the configuration of the intermediate product 500I. The intermediate product 500I has the same configuration as the outdoor heat exchanger 500 shown in Fig. 2, except that the bent portion 21 shown in Fig. 2 has not yet been formed. The outdoor heat exchanger 500 in this embodiment is obtained by subjecting the intermediate product 500I to bending in a plane perpendicular to the header-facing direction.

[0040] Specifically, like the outdoor heat exchanger 500 shown in Figure 2, the intermediate manufactured product 500I also comprises a first header pipe 100A and a second header pipe 100B arranged facing each other, a plurality of heat transfer tubes 200 arranged between the first header pipe 100A and the second header pipe 100B, and a plurality of fins 300 held by the plurality of heat transfer tubes 200.

[0041] However, the first header pipe 100A and the second header pipe 100B of the intermediate product 500I are formed straight over their entire length, unlike the first header pipe 110A and the second header pipe 110B of the outdoor heat exchanger 500 shown in Figure 2.

[0042] 4 will be continued below while still referring to Fig. 5. Step S11, which is an intermediate product preparation step for manufacturing the intermediate product 500I shown in Fig. 5, includes an assembly step (step S111) and a brazing step (step S112).

[0043] In the assembling process (step S111), a plurality of heat transfer tubes 200 and fins 300 are assembled to each of the straight first header pipe 100A and second header pipe 100B. In the brazing process (step S112), each of the straight first header pipe 100A and second header pipe 100B is brazed to the plurality of heat transfer tubes 200, and the plurality of heat transfer tubes 200 is brazed to the fins 300.

[0044] The brazing in the brazing process (step S112) can be performed by heating the temporary assembly obtained in the assembly process (step S111) in a heating furnace. In the heating furnace, the brazing material in each part of the temporary assembly melts, and the brazing of each part can be completed all at once. In this way, the intermediate product 500I is obtained.

[0045] 2, the first header pipe 100A and the second header pipe 100B of the intermediate product 500I have the same structure. Therefore, hereinafter, the first header pipe 100A and the second header pipe 100B of the intermediate product 500I may be collectively referred to as the "header pipe 100."

[0046] 6, each header pipe 100 in the intermediate product 500I has a straight extending bending target portion 20. The bending target portion 20 is subjected to the bending process in step S12 to become a bent portion 21.

[0047] In each header pipe 100 in the intermediate product 500I, the straight portions 22 described above are continuous with both ends of the bending target portion 20. The straight portions 22 are not subjected to bending processing. Therefore, the straight portions 22 are left as they are in the header pipe 110 of the outdoor heat exchanger 500.

[0048] For ease of understanding, Fig. 6 locally illustrates only the bent portion 21 of one header pipe 110 of the outdoor heat exchanger 500 shown in Fig. 2. As for the intermediate product 500I, only the bending target portion 20 of one header pipe 100 is locally illustrated. Furthermore, Fig. 6 omits the illustration of the heat transfer tubes 200 and fins 300 shown in Figs. 2 and 5.

[0049] In step S12, the first header pipe 100A and the second header pipe 100B, each extending straight and having the plurality of heat transfer tubes 200 and the plurality of fins 300 attached thereto, as shown in Fig. 5, are subjected to bending together. As a result, the bending target portions 20 shown in Fig. 6 of each of the first header pipe 100A and the second header pipe 100B become bent portions 21. In this manner, the outdoor heat exchanger 500 is obtained.

[0050] As shown in Figure 5, hereinafter, the length direction of the header pipes 100 of the intermediate product 500I along their pipe paths will also be referred to as the "header pipe length direction." Each header pipe 100 of the intermediate product 500I extends straight over its entire length when viewed in the header-facing direction. Therefore, the imaginary line representing the header pipe length direction of the header pipes 100 of the intermediate product 500I is a straight line.

[0051] Also, for the header pipe 100 of the intermediate product 500I, the direction representing the width of the header pipe 100, that is, the direction perpendicular to the header pipe length direction and the header facing direction, will be called the "header width direction."

[0052] 6 , of both end faces 91 and 92 in the header width direction of the header pipe 100 before bending, the end face 91 that is on the outer side in the direction of the radius of curvature of the bending portion 21 in the bending target portion 20 is referred to as the "outer end face 91." Furthermore, the other end face 92 of both end faces 91 and 92 in the header width direction of the header pipe 100, i.e., the end face 92 that is on the inner side in the direction of the radius of curvature of the bending portion 21 in the bending target portion 20, is referred to as the "inner end face 92." The outer end face 91 in the straight portion 22 and the outer end face 91 in the bending target portion 20 are continuous in the header pipeline length direction. Furthermore, the inner end face 92 in the straight portion 22 and the inner end face 92 in the bending target portion 20 are continuous in the header pipeline length direction.

[0053] Furthermore, with respect to the header width direction of the header pipe 100, the direction from the inner end face 92 toward the outer end face 91 is referred to as the "outer side in the header width direction." Furthermore, with respect to the header width direction of the header pipe 100, the direction from the outer end face 91 toward the inner end face 92 is referred to as the "inner side in the header width direction."

[0054] Similarly, with regard to the header pipe 110 after bending, of both end faces 91 and 92 in the header width direction, at the bending portion 21, the end face 91 that is located outward in the direction of the radius of curvature of the bending portion 21 is referred to as the "outer end face 91." Furthermore, the other end face 92 of both end faces 91 and 92 in the header width direction of the header pipe 110, i.e., at the bending portion 21, the end face that is located inward in the direction of the radius of curvature of the bending portion 21, is referred to as the "inner end face 92." The outer end face 91 in the straight portion 22 and the outer end face 91 in the bending portion 21 are continuous in the header pipeline length direction. Furthermore, the inner end face 92 in the straight portion 22 and the inner end face 92 in the bending portion 21 are continuous in the header pipeline length direction.

[0055] For the header pipe 110, the direction from the inner end face 92 to the outer end face 91 in the header width direction is referred to as the "outward direction in the header width direction," and the direction from the outer end face 91 to the inner end face 92 in the header width direction is referred to as the "inward direction in the header width direction."

[0056] In the bent portion 21 of the header pipe 110, the outer side in the header width direction coincides with the outer side in the direction of the radius of curvature of the bent portion 21, and the inner side in the header width direction coincides with the inner side in the direction of the radius of curvature of the bent portion 21.

[0057] A comparative example will be described below to illustrate the problem that the present embodiment is trying to solve.

[0058] 7 shows the bending target portion 20 of a header pipe 100 according to a comparative embodiment. To facilitate the following description, a header imaginary center plane VP1 is defined for the header pipe 100. The header imaginary center plane VP1 is an imaginary plane that passes through the center of the header width direction dimension of the header pipe 100 and extends in the header pipe length direction and the header facing direction. Because the header pipe 100 before bending extends straight, the header imaginary center plane VP1 of the header pipe 100 is a flat surface.

[0059] In the following, the portion of the bending target portion 20 of the header pipe 100 that is located outward in the header width direction from the header imaginary center plane VP1 will be referred to as the "bending outer portion 20a," and the portion that is located inward in the header width direction from the header imaginary center plane VP1 will be referred to as the "bending inner portion 20b."

[0060] The definitions of the header imaginary center plane VP1, the outer bent portion 20a, and the inner bent portion 20b are common to the comparative example and the embodiment described below.

[0061] The bending target portion 20 of the header pipe 100 according to the comparative embodiment has a rigidity symmetrical structure in which the bending rigidity of the outer bending portion 20 a is equal to the bending rigidity of the inner bending portion 20 b. Therefore, when the bending target portion 20 according to the comparative embodiment is bent, the neutral plane VP2 of bending theoretically coincides with the header virtual center plane VP1.

[0062] The neutral plane VP2 of bending refers to an imaginary plane that passes through a position where the header pipe 100 does not expand or contract when bent in a plane perpendicular to the header-facing direction, and that extends in the header pipe length direction and the header-facing direction. In other words, theoretically, stress accompanying bending does not act on the position of the neutral plane VP2 of bending of the header pipe 100 during bending processing.

[0063] On the other hand, compressive stress acts during the bending process on the portion of the header pipe 100 that is located inward in the header width direction from the neutral plane VP2 of the bending. Also, tensile stress acts during the bending process on the portion of the header pipe 100 that is located outward in the header width direction from the neutral plane VP2 of the bending. The problem is that this tensile stress can cause the inner column 220 shown in Figure 3 to break.

[0064] Returning to Figure 3, a more detailed explanation will be given. As described above, the outer surface of the outer tube 210 at the end 200a of the heat transfer tube 200 is brazed to the inner surface of the insertion opening 10. Therefore, at the location of the end 200a of the heat transfer tube 200 where the tensile stress is applied during the bending process, the inner pillar 220 is pulled in the header pipe length direction through the outer tube 210. As a result, the inner pillar 220 may break.

[0065] The heat transfer tube 200 is subjected to internal pressure from the refrigerant flowing through each flow path 230 inside the heat transfer tube 200. This internal pressure includes a component that expands the heat transfer tube 200 in the header pipe length direction. Therefore, if the inner pillar 220 of the heat transfer tube 200 breaks during bending, the deformation of the heat transfer tube 200 becomes significant. In other words, if the inner pillar 220 breaks, the pressure resistance strength of the heat transfer tube 200 during use will decrease.

[0066] Therefore, it is desirable to have a configuration in which breakage of the inner column 220 is less likely to occur during bending. Hereinafter, we will return to the description of this embodiment, which solves the above-mentioned problems.

[0067] 8 shows the bending target portion 20 of the header pipe 100 according to this embodiment. The bending target portion 20 of each header pipe 100 of the intermediate manufactured product 500I according to this embodiment has an asymmetric rigidity structure in which the bending rigidity of the outer bending portion 20 a is higher than the bending rigidity of the inner bending portion 20 b.

[0068] Therefore, when bending the bending target portion 20 according to this embodiment, the neutral plane VP2 of the bending is shifted outward in the header width direction from the header imaginary center plane VP1. In other words, the neutral plane VP2 of the bending is located outward in the header width direction from the header imaginary center plane VP1, which passes through the center of each insertion opening 10 in the header width direction. For this reason, the area of ​​the opening of each insertion opening 10, which is located outward in the header width direction from the neutral plane VP2 of the bending, is smaller than the area of ​​the opening of the insertion opening 10, which is located inward in the header width direction from the neutral plane VP2 of the bending.

[0069] As a result, the maximum tensile stress acting on the inner post 220 shown in Fig. 3 during bending is reduced compared to when the comparative configuration shown in Fig. 7 is adopted. Therefore, when bending the bending target portion 20, the inner post 220 is less likely to break.

[0070] The above has described the outer bent portion 20a and the inner bent portion 20b of the bending target portion 20 of the intermediate product 500I. Below, the header pipe 110 having the bent portion 21 obtained after the bending process will be described.

[0071] A header imaginary center plane VP1 is also defined for the header pipe 110, which passes through the center of the header width direction of the header pipe 110 and extends in the header pipe length direction and the header facing direction. Because the header pipe 110 has a bent portion 21, the header imaginary center plane VP1 of the header pipe 110 has not only flat portions but also curved portions.

[0072] With regard to the bent portion 21 of the header pipe 110, the portion located outward in the header width direction from the header imaginary center plane VP1 will be called the "outer bent portion 20a," and the portion located inward in the header width direction from the header imaginary center plane VP1 will be called the "inner bent portion 20b."

[0073] The bending process generates tension in the outer bent portion 20a and compression in the inner bent portion 20b, but the strain caused by this tension and compression is less than 20%, so the asymmetric rigidity structure is maintained even after the bending process. In other words, since the bending target portion 20 of the intermediate product 500I has an asymmetric rigidity structure, the bent portion 21 of the outdoor heat exchanger 500 obtained after the bending process also has an asymmetric rigidity structure in which the bending rigidity of the outer bent portion 20a is higher than the bending rigidity of the inner bent portion 20b.

[0074] 9 shows the specific structures of the bending target portion 20 and the bending portion 21 according to this embodiment. The bending target portion 20 and the bending portion 21 have an outer end portion 31 that forms the outer end surface 91 described above, and an inner end portion 32 that forms the inner end surface 92 described above. The outer end portion 31 and the inner end portion 32 are each formed in a plate shape, and face each other in the header width direction.

[0075] The thickness of the outer end 31 is greater than the thickness of the inner end 32. Here, "thickness" refers to the dimension in the header width direction. This results in an asymmetric rigidity structure in which the bending rigidity of the outer bending portion 20a is higher than the bending rigidity of the inner bending portion 20b.

[0076] 10 , a header pipe 100 according to this modification has a first member 101 that constitutes the plate-shaped front end portion 33 where the insertion port 10 is formed, and a second member 102 that constitutes the plate-shaped rear end portion 34 that faces the front end portion 33 in the header-facing direction. The header pipe 100 is formed by fitting the first member 101 and the second member 102 together in the header-facing direction.

[0077] The first member 101 also has an outer end 101 a and an inner end 101 b. The outer end 101 a and the inner end 101 b each extend from the front end 33 and face each other in the header width direction. The outer end 101 a is located outward in the header width direction, and the inner end 101 b is located inward in the header width direction.

[0078] Similarly, the second member 102 has an outer end portion 102 a and an inner end portion 102 b. The outer end portion 102 a and the inner end portion 102 b each extend from the rear end portion 34 and face each other in the header width direction. The outer end portion 102 a is located outward in the header width direction, and the inner end portion 102 b is located inward in the header width direction.

[0079] The outer end 102a is located inward of the outer end 101a in the width direction of the header, and the inner end 102b is located outward of the inner end 101b in the width direction of the header. The outer end 102a and the outer end 101a are joined, and the inner end 102b and the inner end 101b are joined.

[0080] In this modification, the height of the outer end 102a is greater than the height of the inner end 102b. Note that "height" here refers to the dimension in the direction facing the header. This results in an asymmetrical rigidity structure in which the bending stiffness of the outer bending portion 20a is greater than the bending stiffness of the inner bending portion 20b.

[0081] The above has described the configuration of the bending target portion 20. The bent portion 21 obtained by bending the bending target portion 20 also has a structure in which the first member 101 and the second member 102 are fitted together in the header-facing direction, similar to the bending target portion 20. Furthermore, as described above, the rigidity asymmetric structure is maintained even after bending. The other configurations and effects are the same as those of the first embodiment.

[0082] [Embodiment 2] In the above-described embodiment 1, the bending neutral plane VP2 is shifted outward in the header width direction from the header imaginary center plane VP1, thereby suppressing fracture of the inner pillar 220. Fracture of the inner pillar 220 can also be avoided by using a local reinforcement structure that locally reinforces the periphery of the insertion slot 10. Specific examples of local reinforcement structures are described below.

[0083] 11 , the bending target portion 20 according to this embodiment has a plurality of pairs of local reinforcements 41 and 42 that face each other in the header width direction across the insertion opening 10. For each insertion opening 10, a pair of local reinforcements 41 and 42 is locally provided on both sides of the insertion opening 10 in the header width direction. The position in the header pipe length direction of the pair of local reinforcements 41 and 42 provided for each insertion opening 10 is equal to the position in the header pipe length direction of that insertion opening 10. Because the insertion openings 10 are lined up in the header pipe length direction, the pairs of local reinforcements 41 and 42 are also lined up in the header pipe length direction.

[0084] One local reinforcement portion 41 of the pair facing each other in the header width direction is disposed on the outer side of the insertion opening 10 in the header width direction, and the other local reinforcement portion 42 is disposed on the inner side of the insertion opening 10 in the header width direction. Specifically, one local reinforcement portion 41 is provided at the outer end portion 31, and the other local reinforcement portion 42 is provided at the inner end portion 32.

[0085] One local reinforcement portion 41 protrudes outward in the header width direction from the outer end face 91 and extends in the header-facing direction. Similarly, the other local reinforcement portion 42 protrudes inward in the header width direction from the inner end face 92 and extends in the header-facing direction. Because a pair of local reinforcements 41 and 42 is provided on both sides of the insertion opening 10, the dimension of the portion of the bending target portion 20 where the insertion opening 10 is formed in the header width direction is larger than the dimension of the portion of the bending target portion 20 between the insertion openings 10 in the header width direction.

[0086] Therefore, each of the local reinforcements 41 and 42 locally increases the bending rigidity of the portion of the bending target portion 20 where the insertion port 10 is formed, i.e., the portion to which the end portion 200a of the heat transfer tube 200 shown in Fig. 3 is connected, against bending due to bending processing. In other words, each of the local reinforcements 41 and 42 suppresses deformation of the shape of the insertion port 10 due to bending stress.

[0087] As described above, the bending target section 20 according to this embodiment has a configuration in which pairs of local reinforcements 41 and 42 are provided at locations corresponding to each insertion port 10, specifically, at locations that are aligned with each insertion port 10 in the header pipe length direction, and more specifically, at locations located on both sides of each insertion port 10 in the header width direction. The pairs of local reinforcements 41 and 42 suppress deformation of the shape of the insertion port 10 due to bending stress. Therefore, the shape of the insertion port 10 is less likely to deform during bending.

[0088] Specifically, in the bending target portion 20 according to this embodiment, the bending rigidity of the bending outer portion 20a is equal to the bending rigidity of the bending inner portion 20b, but the bending rigidity is locally increased at the positions of the bending target portion 20 where the local reinforcement portions 41 and 42 are provided in the header pipe length direction.

[0089] Therefore, during bending, the portion of the bending target portion 20 between one pair of local reinforcement portions 41 and 42 and the adjacent pair of local reinforcement portions 41 and 42 is preferentially deformed. As a result, deformation of the insertion slot 10 is suppressed.

[0090] Suppressing deformation of the insertion opening 10 means that excessive tensile stress is less likely to act on the end 200a of the heat transfer tube 200 inserted into the insertion opening 10. Therefore, in this embodiment, as in the case of the first embodiment described above, breakage of the inner column 220 due to bending can be suppressed.

[0091] The above has described the configuration of the bending target portion 20. Because each local reinforcement portion 41 is integrated with the outer end portion 31 and each local reinforcement portion 42 is integrated with the inner end portion 32, the positional relationship between the pair of local reinforcements 41 and 42 and the insertion opening 10 is maintained even after bending. In other words, the bent portion 21 obtained by bending the bending target portion 20 has the same structure as the bending target portion 20. Other configurations and effects are the same as those of the first embodiment.

[0092] As described above, brazing can be used as a method for joining the inner surface of the insertion opening 10 and the outer surface of the heat transfer tube 200 shown in Fig. 3. In this case, a clad material whose surface layer is made of a brazing material is used as the material of the bending target 20, and brazing may be performed while the bending target 20 with the heat transfer tube 200 inserted therein is supported by a dedicated jig (hereinafter referred to as a brazing jig). Note that the clad material is formed by bonding together a base material layer made of an alloy that will serve as the base material and a brazing material layer made of an alloy that will serve as the brazing material.

[0093] The brazing jig is used to stably maintain the posture of the bending target portion 20 during heating for brazing. As an example, brazing may be performed in a state in which the outer end portion 31 and the inner end portion 32 of the bending target portion 20 are sandwiched between a pair of brazing jigs in the header width direction.

[0094] Even in this case, according to the present embodiment, the local reinforcement portion 41 protrudes outward in the header width direction from the outer end portion 31, and therefore direct surface contact between the outer end portion 31 and the brazing jig is avoided by the local reinforcement portion 41. Therefore, the outer end portion 31 and the brazing jig are less likely to stick to each other during brazing.

[0095] Similarly, because the local reinforcement portion 42 protrudes inward in the header width direction from the inner end portion 32, direct surface contact between the inner end portion 32 and the brazing jig is avoided by the local reinforcement portion 42. Therefore, the inner end portion 32 and the brazing jig are less likely to stick to each other during brazing.

[0096] [First Modification of Second Embodiment] Hereinafter, another specific example of the local reinforcement structure for suppressing deformation of the insertion slot 10 will be described.

[0097] 12, the bending target portion 20 according to this modification includes a pair of ladder-shaped members 50A and 50B facing each other in the header width direction. One ladder-shaped member 50A is attached to the outer end face 91, and the other ladder-shaped member 50B is attached to the inner end face 92.

[0098] Each of the ladder members 50A and 50B has a pair of beams 51 facing each other in the header-facing direction and a plurality of local reinforcements 52 arranged between the pair of beams 51. Each beam 51 extends in the header pipe length direction. Each local reinforcement 52 extends in the header-facing direction. One end of each local reinforcement 52 is connected to one beam 51, and the other end is connected to the other beam 51.

[0099] In each of the ladder members 50A and 50B, a plurality of local reinforcements 52 are arranged in the header pipe length direction. The local reinforcements 52 are arranged at locations corresponding to the respective insertion openings 10, specifically at locations that are aligned with the respective insertion openings 10 in the header pipe length direction, and more specifically at locations that are located to the sides of the respective insertion openings 10 in the header width direction. The local reinforcement 52 of the ladder member 50A and the corresponding local reinforcement 52 of the ladder member 50B face each other in the header width direction.

[0100] That is, for each insertion port 10, a pair of local reinforcement portions 52 facing each other in the header width direction are provided at locations located on both sides in the header width direction of the insertion port 10. Since the insertion ports 10 are lined up in the header pipe length direction, the pair of local reinforcement portions 52 facing each other in the header width direction are also lined up in the header pipe length direction.

[0101] Since the local reinforcement portions 52 are arranged on both sides of the insertion opening 10, the cross-sectional area of ​​the portion of the bending target portion 20 where the insertion opening 10 is formed is larger than the cross-sectional area of ​​the portion of the bending target portion 20 between the insertion openings 10. Here, the cross-sectional area refers to a cross section perpendicular to the length direction of the header pipe.

[0102] Like the local reinforcement portions 41 and 42 shown in Fig. 11 , the local reinforcement portion 52 according to this modification also locally increases the bending rigidity of the insertion opening 10 of the bending target portion 20, i.e., the portion to which the end portion 200a of the heat transfer tube 200 shown in Fig. 3 is connected, against bending during bending. In other words, each local reinforcement portion 52 suppresses deformation of the shape of the insertion opening 10 due to bending stress. Therefore, the same effects as those of the second embodiment can be obtained with this modification.

[0103] The above has described the configuration of the bending target portion 20. Because the ladder-shaped member 50A is integrated with the outer end portion 31 and the ladder-shaped member 50B is integrated with the inner end portion 32, the positional relationship between the local reinforcement portion 52 and the insertion opening 10 is maintained even after bending. In other words, the bent portion 21 obtained by bending the bending target portion 20 has the same structure as the bending target portion 20. Other configurations and effects are the same as those of the first embodiment.

[0104] Second Modification of Second Embodiment Hereinafter, still another specific example of the local reinforcement structure for suppressing deformation of the insertion slot 10 will be described.

[0105] 13, the header pipe 100 according to this modification has a first member 101 and a second member 102, similar to the configuration shown in Fig. 10. The first member 101 constitutes the front end portion 33 where the insertion port 10 is formed. The second member 102 constitutes the rear end portion 34 that faces the front end portion 33 in the header-facing direction. The header pipe 100 is formed by combining the first member 101 and the second member 102 in the header-facing direction.

[0106] The first member 101 also has an outer end 101a and an inner end 101b that face each other in the header width direction. The outer end 101a and the inner end 101b each extend from the front end 33 in the header-facing direction. The outer end 101a is located outward in the header width direction, and the inner end 101b is located inward in the header width direction. The height of the outer end 101a and the height of the inner end 101b are equal.

[0107] Similarly, the second member 102 has an outer end 102a and an inner end 102b that face each other in the header width direction. The outer end 102a and the inner end 102b each extend in the header-facing direction from the rear end 34. The outer end 102a is located outward in the header width direction, and the inner end 102b is located inward in the header width direction.

[0108] The outer end 102a is located more inward in the header width direction than the outer end 101a. The outer end 102a and the outer end 101a are joined. The inner end 102b is located more outward in the header width direction than the inner end 101b. The inner end 102b and the inner end 101b are joined.

[0109] 10, the height of the outer end 102a is equal to the height of the inner end 102b. The heights of the outer end 102a and the inner end 102b are lower than the heights of the outer end 101a and the inner end 101b.

[0110] The greatest feature of the first member 101 of this modified example is that it has a plurality of local reinforcement portions 60a provided at the outer end portion 101a and a plurality of local reinforcement portions 60b provided at the inner end portion 101b.

[0111] Each local reinforcement portion 60a extends inward in the header width direction from the rear end edge of the outer end portion 101a on the opposite side of the header facing direction from the front end portion 33. The multiple local reinforcement portions 60a are aligned in the header pipe length direction. Each local reinforcement portion 60a is joined to the rear end portion 34.

[0112] Similarly, each local reinforcement portion 60b extends outward in the header width direction from the rear end edge of the inner end portion 101b on the opposite side of the header-facing direction from the front end portion 33. The multiple local reinforcement portions 60b are lined up in the header pipe length direction. Each local reinforcement portion 60b is joined to the rear end portion 34.

[0113] At the inner end 101b, a local reinforcement portion 60b is provided for each local reinforcement portion 60a provided at the outer end 101a at a position facing the local reinforcement portion 60a in the header width direction. In other words, pairs of local reinforcements 60a and 60b facing each other in the header width direction are lined up in the header pipe length direction.

[0114] A pair of local reinforcement portions 60a and 60b facing each other in the header width direction is configured for each insertion port 10. That is, the pair of local reinforcement portions 60a and 60b is arranged at a location corresponding to each insertion port 10. Specifically, the pair of local reinforcement portions 60a and 60b is arranged at a location at the rear end portion 34 that is at the same position in the header pipe length direction as each insertion port 10. The pair of local reinforcement portions 60a and 60b and both end portions of the insertion port 10 in the header width direction may face each other in the header-facing direction.

[0115] Since a pair of local reinforcement portions 60a and 60b is provided at a location corresponding to each insertion port 10, the cross-sectional area of ​​the portion of the bending target portion 20 where the insertion port 10 is formed is larger than the cross-sectional area of ​​the portion of the bending target portion 20 between the insertion ports 10.

[0116] Like the local reinforcement portions 41 and 42 shown in Fig. 11 , the local reinforcement portions 60a and 60b according to this modification locally increase the bending rigidity of the insertion opening 10 of the bending target portion 20, i.e., the portion to which the end portion 200a of the heat transfer tube 200 shown in Fig. 3 is connected, against bending during bending. In other words, each of the local reinforcement portions 60a and 60b suppresses deformation of the shape of the insertion opening 10 due to bending stress. Therefore, the same effects as those of the second embodiment can be obtained with this modification.

[0117] 13 illustrates a configuration in which the heights of the outer end 101a and the inner end 101b are equal, and the heights of the outer end 102a and the inner end 102b are equal, in order to clearly show that the local reinforcements 60a and 60b are meaningful even when not used in combination with the previously described asymmetric rigidity structure. The benefits of the local reinforcements 60a and 60b are exerted regardless of whether the bending rigidity of the header pipe 100 is symmetrical with respect to the previously described header imaginary central plane VP1. Therefore, the heights of the outer end 101a and the inner end 101b may be different, and the heights of the outer end 102a and the inner end 102b may be different.

[0118] In this modification, the local reinforcements 60a and 60b are disposed rearward of the rear end 34. Here, "rearward" refers to the direction from the front end 33 toward the rear end 34 in the header-facing direction. Therefore, the local reinforcements 60a and 60b serve to hold the second member 102.

[0119] Therefore, the first member 101 and the second member 102 can be easily temporarily assembled by inserting the second member 102 in the header pipe length direction between the local reinforcement portions 60a and 60b and the front end portion 33. Here, "temporarily assembling" the members refers to a state in which the members are combined with each other without being joined together.

[0120] When a clad material is used as the material for the first member 101 and the second member 102, the first member 101 and the second member 102 are temporarily assembled and then heated to complete the brazing of the first member 101 and the second member 102. In this case, because the local reinforcements 60a and 60b protrude rearward beyond the rear end portion 34, direct surface contact between the rear end portion 34 and the brazing jig is prevented by the local reinforcements 60a and 60b. Therefore, the rear end portion 34 and the brazing jig are less likely to stick to each other during brazing.

[0121] The configuration of the header pipe 100 of the intermediate product 500I has been described above. Because the local reinforcement portion 60a is integrated with the outer end portion 101a and the local reinforcement portion 60b is integrated with the inner end portion 101b, the positional relationship between the pair of local reinforcement portions 60a and 60b and the insertion opening 10 is maintained even after bending. In other words, the header pipe 110 obtained by bending the header pipe 100 also has the same structure as the header pipe 100. Other configurations and effects are the same as those of the first embodiment.

[0122] [Embodiment 3] In the above-described embodiment 1, an asymmetric rigidity structure is adopted in which the neutral plane VP2 of bending is shifted outward in the header width direction from the header imaginary center plane VP1, thereby avoiding fracture of the inner pillar 220. Furthermore, in the above-described embodiment 2, a local reinforcement structure is adopted in which locations located around the insertion opening 10 in the header pipe 100 are locally reinforced, thereby avoiding fracture of the inner pillar 220.

[0123] The asymmetric rigidity structure and the local reinforcement structure can be used together. Specific examples of such a combination are described below.

[0124] As shown in Fig. 14, the bending target portion 20 according to this embodiment also includes the above-described ladder-shaped member 50A, similar to the configuration shown in Fig. 12. However, unlike the configuration shown in Fig. 12, this embodiment differs in that, of the outer surface of the outer end portion 31 of the bent outer portion 20a and the outer surface of the inner end portion 32 of the bent inner portion 20b, the ladder-shaped member 50A is joined only to the outer surface of the outer end portion 31 of the bent outer portion 20a.

[0125] This results in an asymmetrical rigidity structure in which the bending stiffness of the outer bending portion 20 a is higher than the bending stiffness of the inner bending portion 20 b. Due to this asymmetrical rigidity structure, the neutral plane VP2 of bending is shifted outward in the header width direction from the header imaginary center plane VP1, as shown in FIG.

[0126] Furthermore, in the ladder-shaped member 50A, the local reinforcement portions 52 are arranged at locations corresponding to the respective insertion ports 10, specifically at locations that are positioned at the same position in the header pipe length direction as the respective insertion ports 10, and more specifically at locations that are located to the side in the header width direction of the respective insertion ports 10. Since the insertion ports 10 are lined up in the header pipe length direction, the local reinforcement portions 52 are also lined up in the header pipe length direction.

[0127] Since the local reinforcement portion 52 is arranged on the side of the insertion port 10, the cross-sectional area of ​​the portion of the bending target portion 20 where the insertion port 10 is formed is larger than the cross-sectional area of ​​the portion of the bending target portion 20 between the insertion ports 10.

[0128] Each local reinforcement portion 52 locally increases the bending rigidity of the insertion opening 10 portion of the outer bending portion 20a of the bending target portion 20, i.e., the portion to which the end portion 200a of the heat transfer tube 200 shown in Fig. 3 is connected, against bending during bending. That is, each local reinforcement portion 52 also plays a role in suppressing deformation of the shape of the insertion opening 10 due to bending stress. In other words, the local reinforcement portion 52 provided corresponding to each insertion opening 10 not only contributes to realizing an asymmetric rigidity structure, but also contributes to realizing a locally reinforced structure.

[0129] As described above, in this embodiment, the asymmetric rigidity structure and the local reinforcement structure are used in combination, which further enhances the effect of suppressing breakage of the inner column 220.

[0130] The configuration of the header pipe 100 of the intermediate product 500I has been described above. As described above, the asymmetric rigidity structure is maintained even after bending. Furthermore, because the ladder-shaped member 50A is integrated with the outer end portion 31, the positional relationship between the local reinforcement portion 52 and the insertion opening 10 is maintained even after bending. In other words, the header pipe 110 of the outdoor heat exchanger 500, which is obtained by bending the header pipe 100, also has the same asymmetric rigidity structure and local reinforcement structure as the header pipe 100.

[0131] [First Modification of Third Embodiment] Hereinafter, another specific example of a configuration in which the asymmetric rigidity structure and the local reinforcement structure are used in combination will be described.

[0132] As shown in Fig. 15A, the header pipe 100 according to this modified example is also configured by combining a first member 101 and a second member 102, similar to the configuration shown in Fig. 13. The height of the outer end 101a is equal to the height of the inner end 101b. The height of the outer end 102a is equal to the height of the inner end 102b. The heights of the outer end 102a and the inner end 102b are lower than the heights of the outer end 101a and the inner end 101b.

[0133] The header pipe 100 according to this modification is most characterized in that a plurality of local reinforcement portions 70 are provided at the outer end portion 102a of the second member 102. Hereinafter, the direction from the rear end portion 34 toward the front end portion 33 in the header-facing direction will be referred to as the "forward" direction.

[0134] As shown in Fig. 15B, each local reinforcement portion 70 extends forward from the outer end portion 102a of the second member 102. In the bent outer portion 20a, multiple local reinforcement portions 70 are lined up in the header pipe length direction. Each local reinforcement portion 70 is joined to the outer end portion 101a shown in Fig. 15A.

[0135] A local reinforcement portion 70 is disposed for each insertion port 10 shown in Fig. 15A. That is, the local reinforcement portion 70 is disposed at a location corresponding to each insertion port 10. Specifically, the position of a local reinforcement portion 70 in the header pipe length direction is equal to the position of the insertion port 10 shown in Fig. 15A that corresponds to that local reinforcement portion 70 in the header pipe length direction.

[0136] Since local reinforcement portions 70 are provided at locations corresponding to each insertion port 10, the cross-sectional area of ​​the portion of the bending target portion 20 where the insertion port 10 is formed is larger than the cross-sectional area of ​​the portion of the bending target portion 20 between the insertion ports 10.

[0137] Therefore, each local reinforcement portion 70 locally increases the bending rigidity of the insertion opening 10 portion of the outer bent portion 20a, i.e., the portion to which the end portion 200a of the heat transfer tube 200 shown in Fig. 3 is connected, against bending due to bending processing. In other words, each local reinforcement portion 70 constitutes a local reinforcement structure that suppresses deformation of the shape of the insertion opening 10 due to bending stress.

[0138] In the second member 102, each local reinforcement portion 70 is provided only on the outer end portion 102a included in the outer bent portion 20a, out of the outer end portion 102a included in the outer bent portion 20a and the inner end portion 102b included in the inner bent portion 20b. Therefore, each local reinforcement portion 70 also constitutes the asymmetric rigidity structure described above.

[0139] 15A illustrates a configuration in which the heights of the outer end 101a and the inner end 101b are equal, and the heights of the outer end 102a and the inner end 102b are equal, in order to clearly show that the previously described asymmetric rigidity structure is realized by the local reinforcement portion 70. As long as the presence of the local reinforcement portion 70 has the effect of locally increasing bending rigidity and an asymmetric rigidity structure is realized as a result, the heights of the outer end 101a and the inner end 101b may be different, or the heights of the outer end 102a and the inner end 102b may be different.

[0140] [Second Modification of Third Embodiment] Hereinafter, still another specific example of a configuration in which the asymmetric rigidity structure and the local reinforcement structure are used in combination will be described.

[0141] Figure 16 shows a header pipe 100 according to this modification. The header pipe 100 according to this modification has the same configuration as that shown in Figures 15A and 15B, except for the local reinforcement portions 60a and 60b.

[0142] Furthermore, the configuration of the local reinforcement portions 60a and 60b in the header pipe 100 according to this modified example is the same as the configuration shown in Fig. 13. That is, in the header pipe 100 according to this modified example, the first member 101 also has a plurality of local reinforcement portions 60a provided at the outer end 101a and a plurality of local reinforcement portions 60b provided at the inner end 101b, similar to the configuration shown in Fig. 13.

[0143] According to this modification, by adding local reinforcement parts 60a and 60b that constitute a local reinforcement structure to the configuration shown in Figures 15A and 15B, the effect of suppressing deformation of the shape of the insertion port 10 is further enhanced compared to the configuration shown in Figures 15A and 15B.

[0144] The configuration of the header pipe 100 of the intermediate product 500I has been described above with reference to Figures 15A to 16. As described above, the asymmetric rigidity structure is maintained even after bending. Furthermore, because the local reinforcement portion 70 is integrated with the outer end portion 102a, the positional relationship between the local reinforcement portion 70 and the insertion opening 10 is maintained even after bending. Furthermore, because the local reinforcement portion 60a is integrated with the outer end portion 101a and the local reinforcement portion 60b is integrated with the outer end portion 101b, the positional relationship between the set of local reinforcements 60a and 60b and the insertion opening 10 is maintained even after bending. In other words, the header pipe 110 of the outdoor heat exchanger 500, which is obtained by bending the header pipe 100, also has the same asymmetric rigidity structure and local reinforcement structure as the header pipe 100.

[0145] [Embodiment 4] In the above-described embodiment 1, as shown in Fig. 8, fracture of the inner pillar 220 is suppressed by a configuration in which the neutral plane VP2 of bending is shifted outward in the header width direction from the header imaginary center plane VP1. Fracture of the inner pillar 220 can also be suppressed by a configuration in which the position of the heat transfer tube 200 is shifted inward in the header width direction. A specific example of this will be described below.

[0146] 17 shows the bending target portion 20 according to this embodiment. To simplify the following description, a heat transfer tube imaginary center plane VP3 is defined, which represents the position in the header width direction of the multiple heat transfer tubes 200 lined up in the header pipe length direction. The heat transfer tube imaginary center plane VP3 passes through the center in the header width direction of the end portion 200a of the heat transfer tube 200 that is connected to the header pipe 100, and extends in the header pipe length direction and the header-facing direction. Because the header pipe 100 extends straight before bending, the heat transfer tube imaginary center plane VP3 of the header pipe 100 is a flat surface.

[0147] In this embodiment, the heat transfer tube imaginary center plane VP3 is located more inward in the header width direction than the header imaginary center plane VP1 in the bending target portion 20 of the header pipe 100. Specifically, in the bending target portion 20 of the header pipe 100, the heat transfer tube imaginary center plane VP3 is located between the header imaginary center plane VP1 and the inner end face 92. In other words, in the bending target portion 20, each heat transfer tube 200 is brought closer to the inner end face 92.

[0148] Therefore, the area of ​​the opening of each insertion port 10 that occupies the portion of the header width direction outside the neutral plane VP2 of the bending is smaller than the area of ​​the opening of the portion of the insertion port 10 that occupies the portion of the header width direction inside the neutral plane VP2 of the bending.

[0149] For this reason, even if the neutral plane VP2 of bending is positioned so as to overlap with the header virtual center plane VP1, the maximum tensile stress acting on the inner post 220 shown in Fig. 3 during bending is reduced compared to when the comparative configuration shown in Fig. 7 is adopted. Therefore, breakage of the inner post 220 is unlikely to occur when bending is performed on the bending target portion 20.

[0150] Furthermore, although not shown, in this embodiment, the heat transfer tube imaginary center plane VP3 is also located between the header imaginary center plane VP1 and the inner end face 92 in the straight section 22 of the header pipe 100. In other words, also in the straight section 22, each heat transfer tube 200 is brought closer to the inner end face 92. That is, in the header pipe 100 before bending, the heat transfer tube imaginary center plane VP3 is a plane that extends continuously across the bending target section 20 and the straight section 22.

[0151] Furthermore, the arrangement order in the header width direction of the header imaginary center plane VP1, the heat transfer tube imaginary center plane VP3, and the inner end face 92 is maintained even after bending. That is, even in the bent section 21 and the straight section 22 of the header pipe 110 after bending, the heat transfer tube imaginary center plane VP3 is located between the header imaginary center plane VP1 and the inner end face 92.

[0152] Furthermore, since the header pipe 110 has a bent portion 21 after bending, the header virtual center plane VP1, the heat transfer pipe virtual center plane VP3, and the inner end surface 92 of the header pipe 110 all have not only flat portions but also curved portions.

[0153] 17, it is assumed that the bending stiffness of the outer bending portion 20a is the same as that of the inner bending portion 20b. As in the case of the first embodiment, an asymmetrical rigidity structure may be employed in which the bending stiffness of the outer bending portion 20a is higher than that of the inner bending portion 20b. A specific example of this will be described below.

[0154] Fig. 18 shows the bending target 20 according to this modification. The bending target 20 according to this modification is obtained by adding an asymmetric rigidity structure to the configuration shown in Fig. 17 .

[0155] 17, the heat transfer tube imaginary center plane VP3 is located inward in the header width direction from the header imaginary center plane VP1. Furthermore, this modification employs an asymmetric rigidity structure in which the bending stiffness of the outer bending portion 20a is higher than the bending stiffness of the inner bending portion 20b. As a result, the bending neutral plane VP2 is located outward in the header width direction from the header imaginary center plane VP1.

[0156] The area of ​​the opening of each insertion port 10, which is located outward in the header width direction from the neutral plane VP2 of the bend, is defined as Sa, and the area of ​​the opening of the portion occupying inward in the header width direction from the neutral plane VP2 of the bend, is defined as Sb.

[0157] According to this modified example, the heat transfer tube imaginary center plane VP3 is positioned closer to the inside of the header width direction than the header imaginary center plane VP1, and the bending neutral plane VP2 is shifted closer to the outside of the header width direction than the header imaginary center plane VP1. This makes it possible to make the value of the area ratio Sa / Sb smaller than when either the configuration shown in FIG. 8 or the configuration shown in FIG. 17 is adopted.

[0158] Therefore, during bending, the maximum tensile stress acting on the inner column 220 shown in Fig. 3 can be reduced compared to the configuration shown in Fig. 8 or the configuration shown in Fig. 17. In other words, the possibility of breakage of the inner column 220 can be further reduced.

[0159] [Embodiment 5] The asymmetric rigidity structures and local reinforcement structures described above in embodiment 1, the modified embodiment of embodiment 1, embodiment 2, modified embodiments 1 and 2 of embodiment 2, embodiment 3, modified embodiments 1 and 2 of embodiment 3, and the modified embodiment of embodiment 4 may be provided over the entire length of the header pipes 100, 110.

[0160] In this case, the cross-sectional shape of the header pipes 100, 110 perpendicular to the header pipe length direction is the same at both the ends in the header pipe length direction and the center in the header pipe length direction of the header pipes 100, 110. This is expected to simplify the manufacture of the header pipes 100, 110 and the assembly of the outdoor heat exchanger 500.

[0161] However, a restrictive structure may be adopted in which the asymmetric rigidity structure and local reinforcement structure are limited to only the entire or part of the bending portion 21 and the bending target portion 20. Examples of local reinforcement structures to which a restrictive structure can be applied include structures having local reinforcement portions 41, 42, 52, 60a, 60b, and 70. When a restrictive structure is adopted, it is expected that the weight of the header pipes 100, 110 will be reduced. A specific example of the restrictive structure will be described below as embodiment 5.

[0162] Hereinafter, the structure shown in Fig. 9, i.e., the structure in which the outer end portion 31 is thicker than the inner end portion 32, will be referred to as a "thickened structure." The thickened outer end portion 31 shown in Fig. 9 is an example of a thick portion according to the present disclosure. That is, Fig. 9 shows the thick portion of the outer end portion 31.

[0163] In the following, the structure shown in Figures 11, 12, and 14, i.e., the structure including the portion protruding outward in the header width direction from the outer end face 91 (hereinafter referred to as the outward protrusion), will be referred to as the "protruding structure."

[0164] 11, the local reinforcement portion 41 provided on the outer end portion 31 is an example of an outward protrusion. The plurality of local reinforcement portions 41 and the plurality of local reinforcement portions 42 constitute the protrusion structure.

[0165] 12, the local reinforcement portion 52 of the ladder member 50A on the outer side in the header width direction is an example of an outward protrusion. The pair of ladder members 50A and 50B constitute the protrusion structure.

[0166] 14, the local reinforcement portion 52 of the ladder member 50A is an example of an outward protrusion. The above-described protrusion structure is formed by the ladder member 50A.

[0167] Hereinafter, the thickened structure and the protruding structure will be collectively referred to as the “external reinforcement structure.” One advantage of limiting the area where the external reinforcement structure is provided to only the curved portion 21 out of the curved portion 21 and the straight portion 22 will be described below.

[0168] 19 shows an outdoor unit housing 690 that houses the outdoor heat exchanger 500A and an outdoor unit housing 690 that houses the outdoor heat exchanger 500B. The outdoor heat exchanger 500B employs the restriction structure according to the fifth embodiment. On the other hand, the outdoor heat exchanger 500A does not employ the restriction structure.

[0169] Each outdoor unit housing 690 also houses an outdoor fan 660 and a machine room 680. The machine room 680 is disposed to the side of the outdoor fan 660. The machine room 680 houses the compressor 610, the expander 630, the four-way valve 640, etc. shown in FIG. 1 .

[0170] Each outdoor unit casing 690 is formed in a quadrangle in plan view. Specifically, each outdoor unit casing 690 has a back surface 691 located opposite the outdoor fan 660, a side surface 692 connected to the back surface 691, and a corner 693 between the back surface 691 and the side surface 692.

[0171] The outdoor heat exchanger 500A or 500B is housed between the outdoor fan 660 and the back surface 691. The bent portion 21 of the outdoor heat exchanger 500A, 500B is disposed opposite the inside corner of the corner 693. One straight portion 22 of the outdoor heat exchanger 500A, 500B is disposed opposite the back surface 691, and the other straight portion 22 is disposed opposite the side surface 692. The back surface 691, side surface 692, and corner portion 693 are located outward in the header width direction of the outdoor heat exchanger 500A, 500B.

[0172] In the outdoor heat exchanger 500A that does not employ the above-described restricting structure, the above-described external reinforcing structure 400 is provided not only in the curved portion 21 but also in the straight portion 22. Therefore, the external reinforcing structure 400 is interposed between the back surface 691 and the straight portion 22, and between the side surface 692 and the straight portion 22, respectively.

[0173] On the other hand, in the outdoor heat exchanger 500B according to the fifth embodiment, which employs the above-described restricting structure, the straight portion 22 is not provided with an external reinforcing structure 400. Therefore, when the outdoor heat exchanger 500B is used, one straight portion 22 can be brought closer to the rear surface 691 and the other straight portion 22 can be brought closer to the side surface 692, compared to when the outdoor heat exchanger 500A is used. Furthermore, the external reinforcing structure 400 attached to the bent portion 21 can be accommodated in the inside corner of the corner 693.

[0174] As a result, when the size of the outdoor unit housing 690 used is the same, the length of the header pipe of the outdoor heat exchanger 500B can be made longer than that of the outdoor heat exchanger 500A, which contributes to improving the efficiency of heat exchange in the outdoor heat exchanger 500B.

[0175] Sixth Embodiment The various header pipes 100, 110 exemplified above may be formed using a laminated structure in which multiple layered members are stacked in the header-facing direction. In particular, header pipes 100, 110 having at least one of an asymmetric rigidity structure and a local reinforcement structure are preferably formed using a laminated structure. This is because a laminated structure makes it easy to form the complex outer shape of the header pipes 100, 110 that realizes the asymmetric rigidity structure or the local reinforcement structure.

[0176] As an example, a specific example in which the header pipes 100, 110 shown in FIG. 11 are formed in a laminated structure will be described below.

[0177] Figure 20A shows header pipes 100, 110 according to this embodiment. The outer shapes of these header pipes 100, 110 are the same as those of the header pipes 100, 110 shown in Figure 11. The greatest feature of the header pipes 100, 110 according to this embodiment is that they are formed using a layered structure in which a plurality of layer members 80 are stacked in the header-facing direction.

[0178] Each layer member 80 extends in a plane perpendicular to the header-facing direction. Specifically, each layer member 80 is formed in a flat shape with the header-facing direction as its thickness direction. In the stacked structure, layer members 80 adjacent to each other in the header-facing direction are joined to each other. An example of the joining method is brazing.

[0179] As an example, each layer member 80 may be a clad material. In this case, a plurality of layer members 80 are temporarily assembled in a stacked state in the header facing direction, and the temporarily assembled assembly is heated in a heating furnace, thereby completing the header pipe 100. Note that the heat transfer tube 200 may be inserted into the temporarily assembled assembly. By heating, brazing of each location, including brazing of the layer members 80 together, is completed all at once.

[0180] The layered structure in which adjacent layer members 80 in the header-facing direction are joined together is maintained even when the header pipe 100 is bent. Therefore, the header pipe 110 after bending also has the same layered structure as the header pipe 100 of the intermediate product 500I.

[0181] The layer members 80 will now be described. The multiple layer members 80 constituting the header pipes 100, 110 include one front layer member 81 located at the front end, a rear layer member 83 located at the rear end, and multiple intermediate layer members 82 located between the front layer member 81 and the rear layer member 83.

[0182] 20B, the front layer member 81 forms the front end portion 33 where the insertion slot 10 is formed. The rear layer member 83 forms the rear end portion 34 that faces the front end portion 30 in the header-facing direction.

[0183] Each intermediate layer member 82 is composed of an outer intermediate layer member 82a and an inner intermediate layer member 82b that face each other in the header width direction. The outer intermediate layer member 82a constitutes the outer end portion 31 and local reinforcement portion 41 also shown in Figure 20A. The inner intermediate layer member 82b constitutes the inner end portion 32 and local reinforcement portion 42 also shown in Figure 20A.

[0184] The front layer member 81, the intermediate layer member 82, and the rear layer member 83 can all be formed by pressing, specifically, punching, a flat base material. This results in the front layer member 81, the intermediate layer member 82, and the rear layer member 83 having the same thickness as the base material. Note that the aforementioned clad material may also be used as the base material.

[0185] 20A, the thickness of the front layer member 81, the thickness of the middle layer member 82, and the thickness of the rear layer member 83 are all equal to one another. As mentioned above, the thickness of the layer member 80 refers to the dimension in the header-facing direction.

[0186] 20C shows a cross section of the header pipe 100 at a position between the insertion ports 10. The outer end portion 31 and the inner end portion 32, which face each other in the header width direction, are each formed by a laminated structure.

[0187] In this embodiment, the front end 33 is formed from one front layer member 81, and the rear end 34 is formed from one rear layer member 83. However, the front end 33 may be formed from a plurality of front layer members 81, and the rear end 34 may be formed from a plurality of rear layer members 83.

[0188] Figure 20D shows a cross section of the header pipe 100 at the position of the insertion port 10. As described above, local reinforcement portions 41 and 42 are present at the same position as the insertion port 10 in the header pipe length direction. Therefore, Figure 20D shows not only the outer end portion 31 and the inner end portion 32, but also the local reinforcement portions 41 and 42. The local reinforcement portions 41 and 42 are also formed by a laminated structure.

[0189] Suppose that the outer end 31 and the local reinforcement portion 41, and the inner end 32 and the local reinforcement portion 42 are each formed using a single plate material whose thickness direction is the header width direction, without adopting the laminated structure according to this embodiment. In this case, the local reinforcement portions 41, 42 must be formed by locally adjusting the thickness of the plate material.

[0190] On the other hand, when the layered structure according to the present embodiment is employed, as shown in Fig. 20B, the local reinforcement portions 41 and 42 can be formed depending on the planar shape of each layer member 80. There is no need to adjust the thickness of the layer member 80 in order to form the local reinforcement portions 41 and 42.

[0191] For example, from the perspective of machining, such as press working or cutting, adjusting the planar shape of a workpiece extending in layers is easier than locally adjusting the thickness of a workpiece extending in the shape of a thick plate. Therefore, the laminated structure according to this embodiment makes it possible to easily form header pipes 100, 110 with complex outer shapes, particularly outer shapes with irregularities in the header width direction. Furthermore, the front layer member 81 shown in FIG. 20B can easily be formed with an elongated insertion port 10 by punching using a press.

[0192] [Modification of Sixth Embodiment] The header pipes 100, 110 formed with the above-described laminated structure may have a member therein that closes a portion midway along the header pipe length of the header pipe 100, 110. Specific examples of this will be described below.

[0193] Fig. 21A shows a plan view of the header pipes 100, 110 according to this modified example. As shown by the hidden dashed lines in Fig. 21A, the header pipes 100, 110 according to this modified example have therein a flow blocking wall portion BH that blocks the flow of refrigerant in the length direction of the header pipe.

[0194] Figure 21B is a cross-sectional view of header pipes 100, 110 according to this modified example taken along line ZZ in Figure 21A. As shown in Figure 21B, the flow blocking wall portion BH extends in a plane intersecting the header pipe length direction.

[0195] The flow blocking wall portion BH serves to divide the refrigerant flow path in the header pipe length direction. That is, the header pipes 100, 110 define therein a first flow path F1 and a second flow path F2 that are adjacent to each other in the header pipe length direction via the flow blocking wall portion BH.

[0196] 1 is in operation, the refrigerant that flows out from the first flow path F1 to the heat transfer tube 200 through the insertion port 10 facing the first flow path F1 flows into the second flow path F2 through the insertion port 10 facing the second flow path F2. Alternatively, the refrigerant that flows out from the second flow path F2 to the heat transfer tube 200 through the insertion port 10 facing the second flow path F2 flows into the first flow path F1 through the insertion port 10 facing the first flow path F1.

[0197] 21B , the front end 33 is formed of a single front layer member 81, and the rear end 34 is formed of a single rear layer member 83, as in the sixth embodiment. The greatest feature of this modification is that the flow blocking wall portion BH is formed of a laminated structure. Specifically, the flow blocking wall portion BH is formed of a plurality of intermediate layer members 82.

[0198] 21C shows a plan view of an intermediate layer member 82 according to this modification. In the intermediate layer member 82 according to this modification, unlike the one shown in FIG. 20B, the outer intermediate layer member 82a and the inner intermediate layer member 82b are connected by a portion that constitutes the flow blocking wall portion BH. The other configurations are the same as those of the sixth embodiment.

[0199] 21A and 21B , the flow blocking wall portion BH is disposed at the bending target portion 20 of the header pipe 100 before bending. As described above, the laminated structure is maintained even when bending is performed on the header pipe 100. Therefore, the flow blocking wall portion BH is also disposed at the bent portion 21 of the header pipe 110 after bending.

[0200] The significance of forming the flow blocking wall portion BH with a laminated structure will be described below.

[0201] Suppose that the flow blocking wall portion BH were to be constructed of a single partition plate extending perpendicular to the header pipe length direction without adopting the laminated structure according to this modification. In that case, for reasons of manufacturing convenience and from the viewpoint of ensuring pressure resistance, it would be necessary to provide a joint surface where the partition plate and the front end 33 or the rear end 34 are joined in the header pipe length direction. During bending, a tensile stress perpendicular to the joint surface would act on the joint surface.

[0202] On the other hand, in the flow interruption wall portion BH according to this modification, the layer members 80 are joined together in the header-facing direction. Specifically, as shown in Fig. 21B , in the flow interruption wall portion BH, the middle layer member 82 and the front layer member 81 are joined together in the header-facing direction, the middle layer members 82 are joined together in the header-facing direction, and the middle layer member 82 and the rear layer member 83 are joined in the header-facing direction.

[0203] For this reason, the stress acting on the flow blocking wall portions BH during bending of the header pipe 100 is shear stress parallel to the joint surfaces between the layer members 80. In general, when shear stress acts on the joint surfaces, the joint surfaces are less likely to break than when tensile stress acts on the joint surfaces. Therefore, the header pipe 100 according to this modified example is less likely to break during bending, despite having flow blocking wall portions BH inside it that extend perpendicular to the header pipe length direction.

[0204] The flow blocking wall portions BH according to this modification may be provided on only one of the first header pipe 100A and the second header pipe 100B before bending, or may be provided on both. When provided on both, the number of flow blocking wall portions BH provided on the first header pipe 100A may be different from the number of flow blocking wall portions BH provided on the second header pipe 100B. The same applies to the first header pipe 110A and the second header pipe 110B after bending.

[0205] Furthermore, although Figure 21B illustrates the first flow path F1 and the second flow path F2, in the header pipes 100, 110, the refrigerant flow path may be divided into three or more in the header pipe length direction by multiple flow blocking wall portions BH.

[0206] The embodiment and modifications have been described above. The following modifications are also possible.

[0207] 2 illustrates an example of corrugated fins arranged between adjacent heat transfer tubes 200 in the header pipe length direction as components of the multiple fins 300 held by the multiple heat transfer tubes 200. However, the fins 300 are not limited to corrugated fins. Furthermore, the fins 300 are not essential. The outdoor heat exchanger 500 and the intermediate product 500I may be configured without the fins 300.

[0208] 9 to 16 illustrate header pipes 100 and 110 whose cross sections perpendicular to the header pipe length direction (hereinafter referred to as cross sections) are rectangular, but the shape of the cross sections of the header pipes 100 and 110 is not particularly limited. At least a portion of the cross sections of the header pipes 100 and 110 may be curved. As an example, the cross sections of the header pipes 100 and 110 may have a semi-cylindrical shape with a curved front end 33. Furthermore, the cross sections of the header pipes 100 and 110 may be circular. In other words, the header pipes 100 and 110 may be formed in a cylindrical shape.

[0209] Fig. 2 illustrates a configuration in which the straight portion 22 is continuous with both ends of the bending portion 21 in the length direction of the header pipe. Fig. 6 illustrates a configuration in which the straight portion 22 is continuous with both ends of the bending target portion 20 in the length direction of the header pipe. The straight portion 22 may be continuous with only one end of the bending portion 21 and the bending target portion 20 in the length direction of the header pipe.

[0210] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. The above-described embodiments are intended to explain the present disclosure and do not limit the scope of the present disclosure. The scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and the meaning of the disclosure equivalent thereto are considered to be within the scope of the present disclosure.

[0211] This application is based on Japanese Patent Application No. 2024-023582, filed on February 20, 2024. The entire specification, claims, and drawings of Japanese Patent Application No. 2024-023582 are incorporated herein by reference.

[0212] 10 Insertion port, 20 Bending target portion, 20a Bending outer portion, 20b Bending inner portion, 21 Bending portion, 22 Straight portion, 31 Outer end portion, 32 Inner end portion, 33 Front end portion, 34 Rear end portion, 41 Local reinforcement portion, 42 Local reinforcement portion, 50A, 50B Ladder-shaped member, 51 Beam portion, 52 Local reinforcement portion, 60a, 60b Local reinforcement portion, 70 Local reinforcement portion, 80 Layer member, 81 Front layer member, 82 Intermediate layer member, 82a Outer intermediate layer member, 82b Inner intermediate layer member, 83 Rear layer member, 91 Outer end surface, 92 Inner end surface, 100 Header pipe (intermediate product), 100A First header pipe (intermediate product), 100B Second header pipe (intermediate product), 101 First member, 101a outer end, 101b inner end, 102 second member, 102a outer end, 102b inner end, 110 header pipe, 110A first header pipe, 110B second header pipe, 200 heat transfer pipe, 200a end, 210 outer pipe, 220 inner column, 230 flow path, 300 fin, 400 external reinforcement structure (thick portion, outward protruding portion), 500, 500A, 500B outdoor heat exchanger (heat exchanger), 500I intermediate product, 600 air conditioning device, 610 compressor, 620 indoor heat exchanger, 630 expansion device, 640 four-way valve, 650 indoor fan, 660 outdoor fan, 671 first end piping, 672 second end piping, 680 machine room, 690 Outdoor unit housing, 691 back surface, 692 side surface, 693 corner portion, VP1 header virtual center plane, VP2 bend neutral plane, VP3 heat transfer tube virtual center plane, BH flow blocking wall portion, F1 first flow path, F2 second flow path.

Claims

1. An intermediate product preparation step for manufacturing an intermediate product comprising: a first header pipe and a second header pipe arranged facing each other; and a plurality of heat transfer tubes, each having one end connected to the first header pipe and the other end connected to the second header pipe, the plurality of heat transfer tubes arranged in the header pipe length direction which is the direction in which the first header pipe and the second header pipe extend; A bending process is performed on the first header pipe and the second header pipe of the intermediate manufactured product, thereby forming a bent portion on the first header pipe and the second header pipe that is bent when viewed in the header facing direction, which is the direction in which the first header pipe and the second header pipe face each other. It has, Each of the heat transfer tubes in the aforementioned intermediate manufactured product is The aforementioned header has a hollow, tubular outer tube extending in the direction opposite to the header, The outer tube comprises at least one inner column that divides the inside of the outer tube into multiple flow paths, It has, With respect to the first header tube and the second header tube of the aforementioned intermediate manufactured product, A virtual header center plane of the first header pipe and the second header pipe that passes through the center in the header width direction perpendicular to the header pipe length direction and the header facing direction, and extends in the header pipe length direction and the header facing direction, When you define, Each of the first header tube and the second header tube of the aforementioned intermediate manufactured product is: In the bending target portion that is subjected to the bending process and becomes the curved portion, the bending rigidity of the outer bending portion, which is located outward from the virtual central plane of the header in the direction of the radius of curvature of the curved portion, is higher than the bending rigidity of the inner bending portion, which is located inward from the virtual central plane of the header in the direction of the radius of curvature, thus creating a rigidity asymmetric structure. It has, The aforementioned rigid asymmetric structure is An outward projection is provided on the outer end face of each of the first and second header pipes, which is the end face that is outward with respect to the direction of the radius of curvature in the bending portion of the header width direction, and which protrudes in a direction toward the outer end face from the other end face, which is the inner end face of the other end face, A method for manufacturing a heat exchanger, including the following:

2. Each of the first header tube and the second header tube of the aforementioned intermediate manufactured product is: A straight portion that extends straight when viewed in the direction opposite to the header, and which is continuous with the portion to be bent, It has, The aforementioned outward projection is, Of the outer end face of the portion to be bent and the outer end face of the straight portion, it is provided only on the outer end face of the portion to be bent. The method for manufacturing a heat exchanger according to claim 1.

3. An intermediate product preparation step for manufacturing an intermediate product comprising: a first header pipe and a second header pipe arranged facing each other; and a plurality of heat transfer tubes, each having one end connected to the first header pipe and the other end connected to the second header pipe, the plurality of heat transfer tubes arranged in the header pipe length direction which is the direction in which the first header pipe and the second header pipe extend; A bending process is performed on the first header pipe and the second header pipe of the intermediate manufactured product, thereby forming a bent portion on the first header pipe and the second header pipe that is bent when viewed in the header facing direction, which is the direction in which the first header pipe and the second header pipe face each other. It has, Each of the heat transfer tubes in the aforementioned intermediate manufactured product is The aforementioned header has a hollow, tubular outer tube extending in the direction opposite to the header, The outer tube comprises at least one inner column that divides the inside of the outer tube into multiple flow paths, It has, With respect to the first header tube and the second header tube of the aforementioned intermediate manufactured product, A virtual header center plane of the first header pipe and the second header pipe that passes through the center in the header width direction perpendicular to the header pipe length direction and the header facing direction, and extends in the header pipe length direction and the header facing direction, When you define, Each of the first header tube and the second header tube of the aforementioned intermediate manufactured product is: In the bending target portion that is subjected to the bending process and becomes the curved portion, the bending rigidity of the outer bending portion, which is located outward from the virtual central plane of the header in the direction of the radius of curvature of the curved portion, is higher than the bending rigidity of the inner bending portion, which is located inward from the virtual central plane of the header in the direction of the radius of curvature, thus creating a rigidity asymmetric structure. It has, The aforementioned rigid asymmetric structure is A thickened portion formed on the outer end of each of the first and second header pipes, which is the outer end of the header width direction, in the bending target portion, which is the end that is outward with respect to the direction of the radius of curvature, and which is thicker than the inner end of the other end of the header width direction, A method for manufacturing a heat exchanger, including the following:

4. Each of the first header tube and the second header tube of the aforementioned intermediate manufactured product is: A straight portion that extends straight when viewed in the direction opposite to the header, and which is continuous with the portion to be bent, It has, The aforementioned thickened portion is Of the outer end of the portion to be bent and the outer end of the straight portion, it is provided only on the outer end of the portion to be bent. The method for manufacturing a heat exchanger according to claim 3.

5. An intermediate product preparation step for manufacturing an intermediate product comprising: a first header pipe and a second header pipe arranged facing each other; and a plurality of heat transfer tubes, each having one end connected to the first header pipe and the other end connected to the second header pipe, the plurality of heat transfer tubes arranged in the header pipe length direction which is the direction in which the first header pipe and the second header pipe extend; A bending process is performed on the first header pipe and the second header pipe of the intermediate manufactured product, thereby forming a bent portion on the first header pipe and the second header pipe that is bent when viewed in the header facing direction, which is the direction in which the first header pipe and the second header pipe face each other. It has, Each of the heat transfer tubes in the aforementioned intermediate manufactured product is The aforementioned header has a hollow, tubular outer tube extending in the direction opposite to the header, The outer tube comprises at least one inner column that divides the inside of the outer tube into multiple flow paths, It has, With respect to the first header tube and the second header tube of the aforementioned intermediate manufactured product, A virtual header center plane of the first header pipe and the second header pipe that passes through the center in the header width direction perpendicular to the header pipe length direction and the header facing direction, and extends in the header pipe length direction and the header facing direction, When you define, Each of the first header tube and the second header tube of the aforementioned intermediate manufactured product is: In the bending target portion that is subjected to the bending process and becomes the curved portion, the bending rigidity of the outer bending portion, which is located outward from the virtual central plane of the header in the direction of the radius of curvature of the curved portion, is higher than the bending rigidity of the inner bending portion, which is located inward from the virtual central plane of the header in the direction of the radius of curvature, thus creating a rigidity asymmetric structure. It has, The aforementioned rigid asymmetric structure is A local reinforcing portion is provided only in the outer bending portion of the bent outer portion and the bent inner portion for each heat transfer tube, and the local reinforcing portion is provided in the portion where the end of the heat transfer tube is connected in the bending target portion to locally increase the bending rigidity. Includes, In the bent outer portion of each of the first header pipe and the second header pipe, a plurality of the local reinforcing portions are arranged in the direction of the header pipe length. Heat exchanger manufacturing method.

6. An intermediate product preparation step for manufacturing an intermediate product comprising: a first header pipe and a second header pipe arranged facing each other; and a plurality of heat transfer tubes, each having one end connected to the first header pipe and the other end connected to the second header pipe, the plurality of heat transfer tubes arranged in the header pipe length direction which is the direction in which the first header pipe and the second header pipe extend; A bending process is performed on the first header pipe and the second header pipe of the intermediate manufactured product, thereby forming a bent portion on the first header pipe and the second header pipe that is bent when viewed in the header facing direction, which is the direction in which the first header pipe and the second header pipe face each other. It has, Each of the heat transfer tubes in the aforementioned intermediate manufactured product is The aforementioned header has a hollow, tubular outer tube extending in the direction opposite to the header, The outer tube comprises at least one inner column that divides the inside of the outer tube into multiple flow paths, It has, Each of the first header tube and the second header tube of the aforementioned intermediate manufactured product is: In the bending target portion that is subjected to the bending process and becomes the bent portion, a local reinforcing portion is provided for each heat transfer tube, and the portion in the bending target portion where the end of the heat transfer tube is connected locally increases the bending rigidity with respect to the bending process, It has, In the bending portion of each of the first header pipe and the second header pipe, a plurality of the local reinforcement portions are arranged in the direction of the header pipe length, The aforementioned local reinforcement portion is An outward projection is provided on the outer end face of each of the first and second header pipes, which is the end face that is outward with respect to the direction of the radius of curvature of the bend, in the bending target portion, of the header width direction perpendicular to the header pipe length direction and the header facing direction of each header pipe, and which protrudes in a direction toward the outer end face from the other end face, which is the inner end face, A method for manufacturing a heat exchanger, including the following:

7. Each of the first header tube and the second header tube of the aforementioned intermediate manufactured product is: A straight portion that extends straight when viewed in the direction opposite to the header, and which is continuous with the portion to be bent, It has, The aforementioned outward projection is, Of the outer end face of the portion to be bent and the outer end face of the straight portion, it is provided only on the outer end face of the portion to be bent. The method for manufacturing a heat exchanger according to claim 6.

8. A first header pipe and a second header pipe arranged facing each other, wherein the first header pipe and the second header pipe have a bent portion when viewed in the header facing direction, which is the direction in which the first header pipe and the second header pipe face each other, A plurality of heat transfer tubes, each having one end connected to the first header tube and the other end connected to the second header tube, wherein the plurality of heat transfer tubes are arranged in the direction of the header pipe length, which is the direction in which the first header tube and the second header tube extend, Equipped with, Each of the aforementioned heat transfer tubes is The aforementioned header has a hollow, tubular outer tube extending in the direction opposite to the header, The outer tube comprises at least one inner column that divides the inside of the outer tube into multiple flow paths, It has, With respect to the first header pipe and the second header pipe, A virtual header center plane of the first header pipe and the second header pipe that passes through the center in the header width direction perpendicular to the header pipe length direction and the header facing direction, and extends in the header pipe length direction and the header facing direction, When you define, Each of the first header tube and the second header tube is, In the curved portion, the bending stiffness of the outer portion of the bend, which is located outward from the virtual central plane of the header with respect to the direction of the radius of curvature of the curved portion, in a plane perpendicular to the direction facing the header, is higher than the bending stiffness of the inner portion of the bend, which is located inward from the virtual central plane of the header with respect to the direction of the radius of curvature, thus creating a rigidity asymmetric structure. It has, The aforementioned rigid asymmetric structure is An outward projection is provided on the outer end face of each of the first and second header pipes, which is the end face that is outward in the direction of the radius of curvature at the curved portion, and which protrudes in a direction toward the outer end face from the other end face, which is the inner end face, A heat exchanger, including a heat exchanger.

9. Each of the first header tube and the second header tube is, A straight portion that extends in a straight line when viewed in the direction opposite to the header, and the straight portion that is continuous with the curved portion, It has, The aforementioned outward projection is, Of the outer end face of the curved portion and the outer end face of the straight portion, it is provided only on the outer end face of the curved portion. The heat exchanger according to claim 8.

10. A first header pipe and a second header pipe arranged facing each other, wherein the first header pipe and the second header pipe have a bent portion when viewed in the header facing direction, which is the direction in which the first header pipe and the second header pipe face each other, A plurality of heat transfer tubes, each having one end connected to the first header tube and the other end connected to the second header tube, wherein the plurality of heat transfer tubes are arranged in the direction of the header pipe length, which is the direction in which the first header tube and the second header tube extend, Equipped with, Each of the aforementioned heat transfer tubes is The aforementioned header has a hollow, tubular outer tube extending in the direction opposite to the header, The outer tube comprises at least one inner column that divides the inside of the outer tube into multiple flow paths, It has, With respect to the first header pipe and the second header pipe, A virtual header center plane of the first header pipe and the second header pipe that passes through the center in the header width direction perpendicular to the header pipe length direction and the header facing direction, and extends in the header pipe length direction and the header facing direction, When you define, Each of the first header tube and the second header tube is, In the curved portion, the bending stiffness of the outer portion of the bend, which is located outward from the virtual central plane of the header with respect to the direction of the radius of curvature of the curved portion, in a plane perpendicular to the direction facing the header, is higher than the bending stiffness of the inner portion of the bend, which is located inward from the virtual central plane of the header with respect to the direction of the radius of curvature, thus creating a rigidity asymmetric structure. It has, The aforementioned rigid asymmetric structure is A thickened portion formed on the outer end of each of the first and second header pipes, which is the outer end of the header width direction, in the curved portion, which is the end that is outward with respect to the direction of the radius of curvature, and which is thicker than the inner end of the other end of the header width direction, A heat exchanger, including a heat exchanger.

11. Each of the first header tube and the second header tube is, A straight portion that extends in a straight line when viewed in the direction opposite to the header, and the straight portion that is continuous with the curved portion, It has, The aforementioned thickened portion is Of the outer end of the curved portion and the outer end of the straight portion, it is provided only at the outer end of the curved portion. The heat exchanger according to claim 10.

12. A first header pipe and a second header pipe arranged facing each other, wherein the first header pipe and the second header pipe have a bent portion when viewed in the header facing direction, which is the direction in which the first header pipe and the second header pipe face each other, A plurality of heat transfer tubes, each having one end connected to the first header tube and the other end connected to the second header tube, wherein the plurality of heat transfer tubes are arranged in the direction of the header pipe length, which is the direction in which the first header tube and the second header tube extend, Equipped with, Each of the aforementioned heat transfer tubes is The aforementioned header has a hollow, tubular outer tube extending in the direction opposite to the header, The outer tube comprises at least one inner column that divides the inside of the outer tube into multiple flow paths, It has, With respect to the first header pipe and the second header pipe, A virtual header center plane of the first header pipe and the second header pipe that passes through the center in the header width direction perpendicular to the header pipe length direction and the header facing direction, and extends in the header pipe length direction and the header facing direction, When you define, Each of the first header tube and the second header tube is, In the curved portion, the bending stiffness of the outer portion of the bend, which is located outward from the virtual central plane of the header with respect to the direction of the radius of curvature of the curved portion, in a plane perpendicular to the direction facing the header, is higher than the bending stiffness of the inner portion of the bend, which is located inward from the virtual central plane of the header with respect to the direction of the radius of curvature, thus creating a rigidity asymmetric structure. It has, The aforementioned rigid asymmetric structure is A local reinforcing portion is provided only in the outer bending portion of the bent outer portion and the bent inner portion for each heat transfer tube, and the local reinforcing portion is provided in the portion where the end of the heat transfer tube is connected in the bent portion to locally increase the bending rigidity. Includes, In the bent outer portion of each of the first header pipe and the second header pipe, a plurality of the local reinforcing portions are arranged in the direction of the header pipe length. heat exchanger.

13. A first header pipe and a second header pipe arranged facing each other, wherein the first header pipe and the second header pipe have a bent portion when viewed in the header facing direction, which is the direction in which the first header pipe and the second header pipe face each other, A plurality of heat transfer tubes, each having one end connected to the first header tube and the other end connected to the second header tube, wherein the plurality of heat transfer tubes are arranged in the direction of the header pipe length, which is the direction in which the first header tube and the second header tube extend, Equipped with, Each of the aforementioned heat transfer tubes is The aforementioned header has a hollow, tubular outer tube extending in the direction opposite to the header, The outer tube comprises at least one inner column that divides the inside of the outer tube into multiple flow paths, It has, Each of the first header tube and the second header tube is, In the aforementioned bent portion, a local reinforcing portion is provided for each heat transfer tube, which locally increases the bending rigidity against bending in a plane perpendicular to the direction opposite to the header at the portion where the end of the heat transfer tube is connected in the bent portion, It has, In each of the bends of the first header pipe and the second header pipe, a plurality of the local reinforcing portions are arranged in the direction of the header pipe length. The aforementioned local reinforcement portion is An outward projection is provided on the outer end face of each of the first and second header pipes, which is the end face that is outward with respect to the direction of the radius of curvature of the curved portion, in the case of the curved portion, the outer end face of each of the two end faces, which is the other end face of the two end faces, and which protrudes in a direction toward the outer end face. A heat exchanger, including a heat exchanger.

14. Each of the first header tube and the second header tube is, A straight portion that extends in a straight line when viewed in the direction opposite to the header, and the straight portion that is continuous with the curved portion, It has, The aforementioned outward projection is, Of the outer end face of the curved portion and the outer end face of the straight portion, it is provided only on the outer end face of the curved portion. The heat exchanger according to claim 13.

15. A heat exchanger according to any one of claims 8 to 14, A group of collaborative equipment that constitutes the refrigeration cycle together with the aforementioned heat exchanger, An air conditioning system equipped with the following features.