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

Abstract

The present invention is a heat exchanger manufacturing method wherein, in an intermediate manufacturing product preparation step, an intermediate manufacturing product is manufactured that is provided with a first header pipe (110A), a second header pipe (110B), and a plurality of heat transfer pipes (200). In a bending step, bending is applied to the first header pipe (110A) and the second header pipe (110B) of the intermediate manufacturing product. Each of the heat transfer pipes (200) of the intermediate manufacturing product has, in the interior thereof, at least one internal column that partitions the interior of the heat transfer pipe (200) into a plurality of channels disposed side-by-side in a header width direction. Among the plurality of heat transfer pipes (200) of the intermediate manufacturing product, a bent section disposition heat transfer pipe (200C), end sections of which are connected to sections to be bent of the first header pipe (110A) and the second header pipe (110B), comprises a pair of end section pipes (210) and a body section pipe (220). Among the body section pipe (220) and the pair of end section pipes (210), only the body section pipe (220) has the internal column.

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 inner column that divides the interior of the heat transfer tube into multiple flow paths. The multiple flow paths defined inside the heat transfer tube by the inner column are aligned in the width direction of the header pipe, which is perpendicular to the longitudinal direction of the heat transfer tube and the longitudinal directions of the first and second header pipes.

[0004] Japanese Patent Application Laid-Open No. 2022-19459

[0005] There are cases where it is desirable to obtain the above-mentioned heat exchanger by a manufacturing method in which a first header pipe and a second header pipe each having a plurality of heat transfer tubes connected thereto are bent to form the above-mentioned bent portions.

[0006] However, in this case, the intermediate product to be bent may be damaged due to the tensile stress that occurs during bending. An example of "damage due to tensile stress" is the breakage of the inner column due to the tensile stress.

[0007] An object of the present disclosure is to provide a heat exchanger manufacturing method that is less likely to cause breakage due to tensile stress 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.

[0008] 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 in the intermediate product has at least one internal pillar therein that divides the interior of the heat transfer tube into a plurality of flow paths aligned in a header width direction perpendicular to the header facing direction and the header pipe length direction. Among the heat transfer tubes in the intermediate product, the bent portion-arranged heat transfer tubes, whose ends are connected to bending target portions in the first header pipe and the second header pipe that are bent by bending, have a pair of end tubes that form one end and the other end, and a main body tube that is arranged between the pair of end tubes and forms a portion of the bent portion-arranged heat transfer tube that includes the center in the header-facing direction. Of the main body tube and the pair of end tubes, only the main body tube has an inner column.

[0009] If an inner pillar is present at the end of a bent portion-arranged heat transfer tube, the inner pillar may break due to tensile stress when bending the bending target portion with the end connected.

[0010] On the other hand, in the heat exchanger manufacturing method according to the present disclosure, only the main body tube of the bent portion-disposed heat transfer tube, out of the main body tube and a pair of end tubes, has an inner column. In other words, the end tubes that form the ends connected to the first and second header tubes are not provided with an inner column. This avoids the problem of inner column breakage due to tensile stress when bending the bending target portion with the end tubes connected. In other words, breakage due to tensile stress is less likely to occur when forming bends in the first and second header tubes.

[0011] FIG. 1 is a conceptual diagram showing the configuration of an air conditioning device according to the first embodiment; FIG. 2 is a perspective view showing the configuration of an outdoor heat exchanger according to the first embodiment; FIG. 3 is a flowchart showing a method for manufacturing an outdoor heat exchanger according to the first embodiment; FIG. 4 is a conceptual diagram for explaining a bending process according to the first embodiment; FIG. 5 is a conceptual diagram showing the configuration of a bent portion-arranged heat transfer tube according to the first embodiment; FIG. 6 is a conceptual diagram showing a cross section of a main body tube according to the first embodiment;

[0012] Hereinafter, an air conditioner according to an embodiment will be described with reference to the drawings, in which the same or corresponding parts are designated by the same reference numerals.

[0013] [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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] Each of the first header pipe 110A and the second header pipe 110B is an example of a header pipe according to the present disclosure. 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. When one of the first header pipe 110A and the second header pipe 110B is projected onto the other in the header facing direction, the projected area overlaps with the other.

[0022] 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."

[0023] 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.

[0024] Specifically, the first header pipe 110A and the second header pipe 110B have bent portions 21 when viewed in the header-facing direction. The first header pipe 110A and the second header pipe 110B also have straight portions 22 that extend straight when viewed in the header-facing direction. The straight portions 22 are continuous with both ends of the bent portions 21 in the header pipe length direction.

[0025] 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.

[0026] 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.

[0027] The first header pipe 110A and the second header pipe 110B have the same structure, ignoring the details including the locations where the first end piping 671 and the second end piping 672 are connected. Therefore, hereinafter, the first header pipe 110A and the second header pipe 110B may be collectively referred to as the "header pipes 110."

[0028] 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 .

[0029] A method for manufacturing an outdoor heat exchanger according to this embodiment will be described below with reference to Fig. 3. This is one example of a method for manufacturing a heat exchanger according to the present disclosure.

[0030] The above-described bent portions 21 of the pair of header pipes 110 are formed by bending (step S12). Note that step S12 is an example of a bending process according to the present disclosure.

[0031] Therefore, before step S12, an intermediate product to be subjected to bending is produced (step S11). Note that step S11 is an example of an intermediate product preparation step according to the present disclosure.

[0032] 4, the intermediate product 500I has the same configuration as the outdoor heat exchanger 500, except that the bent portion 21 is not yet 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.

[0033] Specifically, 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.

[0034] 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 of the intermediate product 500I are not subjected to bending. In other words, the straight portions 22 of the intermediate product 500I are an example of a portion not to be bent according to the present disclosure. Therefore, the straight portions 22 are left as they are in the header pipes 110 of the outdoor heat exchanger 500.

[0035] For ease of understanding, Fig. 4 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. 4 omits the illustration of the heat transfer tubes 200 and fins 300 shown in Fig. 2.

[0036] Although not shown, the intermediate product 500I, like the outdoor heat exchanger 500, also comprises a pair of header pipes 100 arranged facing each other, a plurality of heat transfer pipes 200 arranged between the pair of header pipes 100, and a plurality of fins 300 held by the plurality of heat transfer pipes 200.

[0037] 3 will be continued below while still referring to Fig. 4. Step S11, which is an intermediate product preparation step for manufacturing the intermediate product 500I, includes an assembly step (step S111) and a brazing step (step S112).

[0038] In the assembling process (step S111), a plurality of heat transfer tubes 200 and fins 300 are assembled to each pair of straight header tubes 100. In the brazing process (step S112), each pair of straight header tubes 100 is brazed to the plurality of heat transfer tubes 200, and the plurality of heat transfer tubes 200 are brazed to the fins 300.

[0039] 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.

[0040] Then, in step S12, the pair of header pipes 100, each extending straight and having the plurality of heat transfer tubes 200 and the plurality of fins 300 attached thereto, are subjected to bending together. As a result, the bending target portions 20 of each of the pair of header pipes 100 become bent portions 21. In this manner, the outdoor heat exchanger 500 is obtained.

[0041] Hereinafter, with respect to the header pipes 100 of the intermediate product 500I, the lengthwise direction along the pipe path of the header pipe 100 will be referred to as the "header pipe length direction," and the direction in which the pair of header pipes 100 face each other will be referred to as the "header facing 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 pipe 100 of the intermediate product 500I is a straight line.

[0042] In the following description, the direction perpendicular to the header facing direction and the header pipe length direction, that is, the direction representing the width of the header pipes 100 and 110, will be referred to as the "header width direction."

[0043] Furthermore, hereinafter, of the two end faces of the header pipe 100 that face each other in the header width direction, the end face that is on the outer side in the bending target section 20 with respect to the direction of the radius of curvature of the bending section 21 will be referred to as the "outer end face 91." Furthermore, of the two end faces of the header pipe 100 that face each other in the header width direction, that is, the end face that is on the inner side in the bending target section 20 with respect to the direction of the radius of curvature of the bending section 21 will be referred to as the "inner end face 92."

[0044] Similarly, for the header pipe 110, of the two end faces opposing each other in the header width direction, at the bending portion 21, the end face 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 of the header pipe 110 of the two end faces opposing each other in the header width direction, that is, 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."

[0045] Furthermore, hereinafter, the direction from the inner end face 92 toward the outer end face 91 in the header width direction of the header pipe 100 will be referred to as the "outer side in the header width direction." Furthermore, the direction from the outer end face 91 toward the inner end face 92 in the header width direction of the header pipe 100 will be referred to as the "inner side in the header width direction."

[0046] Similarly, with regard to the header pipe 110, the direction from the inner end face 92 toward the outer end face 91 in the header width direction is referred to as the "outer side in the header width direction," and the direction from the outer end face 91 toward the inner end face 92 in the header width direction is referred to as the "inner side in the header width direction." At the bent portion 21 of the header pipe 110, the outer side in the header width direction coincides with the outward 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 inward side in the direction of the radius of curvature of the bent portion 21.

[0047] In the following description, among the plurality of heat transfer tubes 200 in the intermediate product 500I, those connected to the straight portion 22 of the header pipe 100 will be referred to as "straight portion-disposed heat transfer tubes 200S." Furthermore, among the plurality of heat transfer tubes 200 in the outdoor heat exchanger 500, which is a finished product, those connected to the straight portion 22 of the header pipe 110 will also be referred to as "straight portion-disposed heat transfer tubes 200S."

[0048] Although only a portion of the straight portion-arranged heat transfer tube 200S is shown in Figure 4, both end portions 200a of the straight portion-arranged heat transfer tube 200S shown in Figure 2 are connected to a pair of straight portions 22 facing each other in the header facing direction.

[0049] In the following description, among the plurality of heat transfer tubes 200 in the intermediate product 500I, those connected to the bending portion 20 of the header pipe 100 will be referred to as "bend portion-arranged heat transfer tubes 200C." Furthermore, among the plurality of heat transfer tubes 200 in the outdoor heat exchanger 500, which is a finished product, those connected to the bending portion 21 of the header pipe 110 will also be referred to as "bend portion-arranged heat transfer tubes 200C."

[0050] Although Figure 4 shows only a portion of the bend-positioned heat transfer tube 200C, both end portions 200a of the bend-positioned heat transfer tube 200C shown in Figure 2 are connected to a pair of bending target portions 20 facing each other in the header-facing direction, or to a pair of bending portions 21 facing each other in the header-facing direction.

[0051] The most notable feature of the intermediate product 500I and the outdoor heat exchanger 500 according to this embodiment is the configuration of each bend portion-arranged heat transfer tube 200 C. Therefore, the configuration of each bend portion-arranged heat transfer tube 200 C will be specifically described below.

[0052] As shown in FIG. 5, the bend-positioned heat transfer tube 200C extending straight in the header-facing direction has a pair of end tubes 210 located at both ends in the header-facing direction, a main body tube 220 located between the pair of end tubes 210, and a pair of joint parts 230 located at both ends of the main body tube 220 in the header-facing direction.

[0053] One of the pair of end tubes 210 in the bend portion-located heat transfer tube 200C is connected to one of the pair of header tubes 100 facing each other in the header-facing direction, and the other of the pair of end tubes 210 is connected to the other of the pair of header tubes 100. In other words, one end tube 210 constitutes one end 200a of the bend portion-located heat transfer tube 200C that is connected to one header tube 100. The other end tube 210 constitutes the other end 200a of the bend portion-located heat transfer tube 200C that is connected to the other header tube 100. The main body tube 220 constitutes a portion of the bend portion-located heat transfer tube 200C that includes the center in the header-facing direction.

[0054] One of the coupling parts 230 connects one end of the main body pipe 220 to one of the end pipes 210. The other coupling part 230 connects the other end of the main body pipe 220 to the other end pipe 210. Each coupling part 230 is joined to the main body pipe 220 and the end pipe 210. In this embodiment, the joining is achieved by brazing, but joining with an adhesive may also be used.

[0055] 6 shows a cross section perpendicular to the header-facing direction of the main body pipe 220. The main body pipe 220 has a hollow, tubular outer pipe 220a extending straight in the header-facing direction, and a plurality of inner pillars 220b that partition the interior of the outer pipe 220a.

[0056] The outer pipe 220a 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 pillars 220b divide the interior of the outer pipe 220a into multiple flow paths 220c that are aligned in the header width direction.

[0057] Refrigerant flows through each of the flow paths 220c. Specifically, the refrigerant flowing through each of the flow paths 220c joins together at the end pipe 210 via a joint part 230 shown in FIG. 5, or the refrigerant flowing through the end pipe 210 is distributed to each of the flow paths 220c via the joint part 230.

[0058] 6 illustrates a configuration in which 20 flow paths 220c are defined by 19 inner pillars 220b, but the number of inner pillars 220b is not limited thereto. Two flow paths 220c may be defined by one inner pillar 220b.

[0059] Specifically, the main body pipe 220 is configured by a pipe called a "flat pipe." The flat pipe has a cross section perpendicular to the length direction that is elongated in one direction, and has an inner pillar 200b inside that defines a plurality of flow paths aligned in that one direction.

[0060] The above has described the configuration of the main body tube 220 of the bent portion-arranged heat transfer tube 200C. The straight portion-arranged heat transfer tube 200S shown in Figure 4 is also configured using the same piping as the flat tubes that make up the main body tube 220 over its entire length.

[0061] The bent section heat transfer tube 200C differs from the straight section heat transfer tube 200S in that, as shown in FIG. 5, end tubes 210 are connected to both ends of the flat tube that constitutes the main body tube 220.

[0062] In order to explain the significance of the end tube 210 in the bend-portion-arranged heat transfer tube 200C, a comparative example will be described below.

[0063] In the comparative example, the bent heat transfer tube 200C has the same configuration as the straight heat transfer tube 200S. That is, the bent heat transfer tube 200CC according to the comparative example (hereinafter referred to as the "bent heat transfer tube 200CC") is made up of flat tubes shown in Fig. 6 over its entire length, just like the straight heat transfer tube 200S. The bent heat transfer tube 200CC according to the comparative example does not include the end tube 210 and the joint part 230 shown in Fig. 5.

[0064] 7 shows a cross section of a comparative example of a bend-arranged heat transfer tube 200CC at a portion where the bend-arranged heat transfer tube 200CC is connected to a header tube 100. In this specification, the term "cross section" refers to a cross section perpendicular to the header-facing direction. The header tube 100 has an insertion opening 10C formed for each heat transfer tube 200, and the corresponding bend-arranged heat transfer tube 200CC is inserted into the insertion opening 10C.

[0065] The outer surface of the bend portion heat transfer tube 200CC is joined to the inner surface of the insertion opening 10C. The bend portion heat transfer tube 200CC and the header tube 100 are both made of metal. Specifically, the joining of the outer surface of the bend portion heat transfer tube 200CC to the inner surface of the insertion opening 10C is achieved by brazing.

[0066] For ease of explanation, a header virtual center plane VP1 is defined for the header tube 100 as an imaginary plane that passes through the center of the header width direction dimension of the header tube 100 and extends in the header pipe length direction and the header facing direction. The bend portion-arranged heat transfer tube 200CC is arranged at a position where the center of the header width direction overlaps with the header virtual center plane VP1.

[0067] Furthermore, the header pipe 100 has a structure in which a neutral plane VP2 of bending coincides with the header imaginary center plane VP1 when bending the bending target portion 20. The definition of the header imaginary center plane VP1 and the position of the neutral plane VP2 of bending are common to the comparative example and the embodiment.

[0068] The neutral plane VP2 of bending refers to an imaginary plane that passes through a position in the header pipe 100 that does not expand or contract when the header pipe 100 is 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 associated with bending does not act on the position of the neutral plane VP2 of bending of the header pipe 100 during bending.

[0069] On the other hand, compressive stress acts on the portions of the header pipe 100 and the bent portion-arranged heat transfer tubes 200CC that are located inward in the header width direction from the neutral plane VP2 of the bend during the bending process. Also, tensile stress acts on the portions of the header pipe 100 and the bent portion-arranged heat transfer tubes 200CC that are located outward in the header width direction from the neutral plane VP2 of the bend during the bending process. This tensile stress can cause breakage, which is a problem.

[0070] In particular, the bend-portion-arranged heat transfer tube 200CC according to the comparative example has an elongated shape in the header width direction. Therefore, among the multiple inner columns 220b, those located outward in the header width direction from the neutral plane VP2 of the bend, especially the inner column 220b located furthest outward in the header width direction, are subjected to large tensile stress during bending. Therefore, the inner column 220b may break due to the tensile stress.

[0071] Furthermore, at the joint between the outer surface of the bend portion-positioned heat transfer tube 200CC and the inner surface of the insertion port 10C, at the portion located outward in the header width direction from the neutral plane VP2 of the bend, there is a possibility that the outer surface of the bend portion-positioned heat transfer tube 200CC will peel off from the inner surface of the insertion port 10C during bending processing.

[0072] In addition, compressive stress may act on the portion of the bent heat transfer tube 200CC located inward in the header width direction from the neutral plane VP2 of the bend during bending, which may cause problems such as crushing of the bent heat transfer tube 200CC and buckling of the inner column 220b.

[0073] However, from the viewpoint of ensuring sufficient pressure resistance of the heat transfer tube 200, which is subjected to high pressure during use, damage caused by tensile stress, such as fracture and peeling, is a more serious problem than damage caused by compressive stress, such as crushing and buckling.

[0074] Specifically, if the inner column 220b breaks, the pressure resistance strength during use of the heat transfer tube 200 will decrease. When the heat transfer tube 200 is in use, a high-pressure refrigerant flows through each flow path 220c, so there is a concern that the break will spread from the point where the inner column 220b first breaks.

[0075] Therefore, a structure that is less susceptible to breakage due to tensile stress during bending is desired. Now, we will return to the description of the embodiment that solves the above-described problems.

[0076] 8 shows a cross section of a portion of a bend-arranged heat transfer tube 200C according to this embodiment that is connected to a header tube 100, i.e., the aforementioned end tube 210. An insertion opening 10 is formed in the header tube 100 for each heat transfer tube 200, and the corresponding end tube 210 is inserted into the insertion opening 10.

[0077] The outer surface of the end tube 210 is joined to the inner surface of the insertion port 10. The bend portion-arranged heat transfer tube 200C and the header tube 100 are both made of metal. The joining of the outer surface of the end tube 210 to the inner surface of the insertion port 10 is specifically achieved by brazing. This is the same as in the comparative example.

[0078] In this embodiment, the end tubes 210 connected to the header tube 100 are not provided with the inner pillars 220b shown in Figures 6 and 7. That is, in the bend-portion-arranged heat transfer tube 200C according to this embodiment shown in Figure 5, only the main body tube 220 of the main body tube 220 and the pair of end tubes 210 has the inner pillars 220b shown in Figures 6 and 7. The end tube 210 is formed of a tubular body without any inner pillars 220b or other partitions inside.

[0079] Therefore, according to this embodiment, the problem of breakage of the inner pillars 220b caused by tensile stress that occurs during bending of the header pipe 100 with the heat transfer tubes 200 connected thereto is avoided.

[0080] For ease of explanation, the projection area obtained by perpendicularly projecting the end tube 210 of the bend-arranged heat transfer tube 200C onto an imaginary plane PP extending perpendicular to the header-facing direction is defined as the "end tube projection area RA." Also, the projection area obtained by perpendicularly projecting the main body tube 220 of the bend-arranged heat transfer tube 200C shown in Figure 5 onto the imaginary plane PP is defined as the "main body tube projection area RB."

[0081] In this embodiment, as in the comparative example, the bent portion-arranged heat transfer tube 200C is arranged at a position where the center in the header width direction overlaps with the header imaginary center plane VP1. Also, the neutral plane VP2 of the bend coincides with the header imaginary center plane VP1.

[0082] However, in this embodiment, the outer edge RA_O of the end pipe projection area RA in the header width direction is located more inward in the header width direction than the outer edge RB_O of the main body pipe projection area RB in the header width direction.

[0083] Therefore, the maximum tensile stress acting on the end tube 210 during bending can be kept smaller than the maximum tensile stress acting on the bend-portion-arranged heat transfer tube 200CC according to the comparative example shown in Fig. 7. Therefore, peeling is unlikely to occur at the joint between the outer surface of the end tube 210 and the inner surface of the insertion opening 10, in the portion located outward in the header width direction from the neutral plane VP2 of the bend.

[0084] In this embodiment, the inner edge RA_I of the end pipe projection area RA in the header width direction is positioned outward in the header width direction from the inner edge RB_I of the main pipe projection area RB in the header width direction.

[0085] Therefore, the maximum compressive stress acting on the end tube 210 during bending can be made smaller than the maximum compressive stress acting on the bent portion-arranged heat transfer tube 200CC according to the comparative example shown in Fig. 7. Therefore, the incidence of crushing of the end tube 210 can also be reduced.

[0086] In this embodiment, the maximum dimension of the end pipe projection area RA in the header pipe length direction is greater than the maximum dimension of the main body pipe projection area RB in the header pipe length direction.

[0087] Therefore, even if the end tube 210 is deformed to some extent by the tensile or compressive stress caused by the bending process, the rate of change in the dimension of the end tube 210 in the header pipe length direction can be kept smaller than the rate of change in the dimension of the bend-portion-arranged heat transfer tube 200CC in the header pipe length direction according to the comparative embodiment, which contributes to reducing the rate of breakage caused by the tensile or compressive stress.

[0088] In the bend-arranged heat transfer tube 200C according to this embodiment, the end tube 210 can be manufactured separately from the flat main tube 220, as shown in Fig. 5. In other words, the end tube 210, which is manufactured separately from the main tube 220, can be connected to the main tube 220 by the joint part 230.

[0089] Therefore, it is easy to design the thickness of the end tube 210 independently of the thickness of the main body tube 220. Therefore, by forming the end tube 210 thicker than the main body tube 220, it is easy to realize a configuration in which the bending rigidity of the end tube 210 against the bending process (hereinafter simply referred to as "bending rigidity") is higher than the bending rigidity of the main body tube 220. This contributes to reducing the incidence of breakage of the bend portion-arranged heat transfer tube 200C due to tensile stress or compressive stress.

[0090] 8 illustrates the header pipe 100 of the intermediate product 500I. The outdoor heat exchanger 500 is obtained by bending the header pipe 100. Therefore, the header pipe 110 of the outdoor heat exchanger 500 also has a similar structure to the header pipe 100 of the intermediate product 500I, except that it has the bent portion 21 shown in FIG.

[0091] As described above, according to this embodiment, breakage of the intermediate product 500I is unlikely to occur during bending. Therefore, it is possible to make the bending portion 21 shown in FIG. 4 tighter than in the past, that is, to make the curvature of the bending portion 21 larger than in the past. This contributes to reducing the dimension of the bending portion 21 in the header pipe length direction and to reducing the size of the housing that houses the heat exchanger 500 according to this embodiment.

[0092] 8 illustrates an example of an intermediate product 500I having both of the following configurations: (i) a configuration in which the end tubes 210 are not provided with the inner columns 220b shown in FIGS. 6 and 7; and (ii) a configuration in which the outer edge RA_O of the end tube projection area RA in the header width direction is positioned more inward in the header width direction than the outer edge RB_O of the main body tube projection area RB. The intermediate product 500I and the heat exchanger 500 may employ only one of the above configurations (i) and (ii).

[0093] In this modification, only the configuration (i) of the above configurations (i) and (ii) is adopted. According to this modification, since the end tube 210 is not provided with the inner column 220b, the problem of breakage of the inner column 220b is avoided even without the above configuration (ii).

[0094] [Second Modification of First Embodiment] In this modification, only the configuration (ii) is adopted out of the configurations (i) and (ii) above. That is, in this modification, the outer edge RA_O of the end pipe projection area RA in the header width direction is positioned more inward in the header width direction than the outer edge RB_O of the main pipe projection area RB in the header width direction.

[0095] Therefore, even if the end tube 210 is also provided with the inner pillar 220b, the maximum tensile stress acting on the end tube 210 during bending can be kept smaller than the maximum tensile stress acting on the bend portion-arranged heat transfer tube 200CC according to the comparative example shown in Fig. 7. As a result, the inner pillar 220b is less likely to break.

[0096] [Third Modification of First Embodiment] In addition to the above configurations (i) and (ii), the intermediate product 500I shown in FIG. 8 further includes the following configurations: (iii) an inner edge RA_I of the end pipe projection area RA in the header width direction is positioned outward in the header width direction than an inner edge RB_I of the main body pipe projection area RB in the header width direction; and (iv) a maximum dimension of the end pipe projection area RA in the header pipe length direction is larger than a maximum dimension of the main body pipe projection area RB in the header pipe length direction.

[0097] However, the configurations (iii) and (iv) are not essential. Therefore, in this modified example, at least one of the configurations (i) and (ii) is provided, and at least one of the configurations (iii) and (iv) is omitted.

[0098] [Embodiment 2] Figure 8 illustrates an example of an end tube 210 having a circular cross-sectional shape before bending. The cross-sectional shape of the end tube 210 may be non-circular before bending, but may become closer to a circle as a result of plastic deformation associated with the bending. Specific examples of this will be described below.

[0099] 9 shows the cross-sectional shapes of the end tube 210 according to this embodiment before and after bending. As mentioned above, the "cross-section" refers to a cross section perpendicular to the header-facing direction.

[0100] 9, the cross section of the portion 210a of the end pipe 210 located at the boundary with the coupling part 230 (hereinafter referred to as the base end portion) is shown as the A-A cross section. The cross section of the middle portion 210b of the end pipe 210 in the header-facing direction (hereinafter referred to as the middle portion) is shown as the B-B cross section. The cross section of the portion 210c of the end pipe 210 that joins with the inner surface of the insertion port 10 of the header pipe 100 (hereinafter referred to as the insertion port joint portion) is shown as the C-C cross section.

[0101] The insertion opening joint portion 210c is an example of a connection portion of the end tube 210 that is connected to the bending target portion 20.

[0102] In the cross sections of the base end 210 a, the intermediate portion 210 b, and the insertion port joint 210 c before and after bending, the outer edge in the header width direction is located outward from the header imaginary center plane VP1, and the inner edge in the header width direction is located inward from the header imaginary center plane VP1. As in the first embodiment, the neutral plane VP2 of bending during bending coincides with the header imaginary center plane VP1.

[0103] The cross section of the insertion port joint 210c before bending has a non-circular shape. Specifically, the cross section of the insertion port joint 210c before bending has a shape in which, in the portion that will be subjected to tensile stress during bending, the dimension in the length direction of the header pipe becomes smaller as the portion that will be subjected to greater tensile stress becomes larger, and in the portion that will be subjected to compressive stress during bending, the dimension in the length direction of the header pipe becomes larger as the portion that will be subjected to greater compressive stress becomes larger.

[0104] That is, the cross section of the insertion port joint 210c before bending has a shape in which the dimension in the header pipe length direction gradually decreases as it moves outward in the header width direction, more specifically, a triangular shape with rounded corners.

[0105] The insertion opening 10 of the header pipe 100 of the intermediate product 500I also has the same outer shape as the insertion opening joint portion 210c before bending. The outer surface of the insertion opening joint portion 210c before bending is brazed to the inner surface of the insertion opening 10 over the entire periphery.

[0106] During the bending process, the end tube 210 is subjected to greater tensile stress in the region closer to the outer edge in the header width direction, and greater compressive stress in the region closer to the inner edge in the header width direction. Therefore, the metal insertion port joint 210c undergoes plastic deformation in which the region closer to the outer edge in the header width direction expands in the header pipe length direction, and the region closer to the inner edge in the header width direction contracts in the header pipe length direction. In this way, the cross section of the insertion port joint 210c becomes closer to a circle due to the plastic deformation caused by the bending process.

[0107] The bending process also plastically deforms the area around the insertion opening 10 in the bending target portion 20 of the metal header pipe 100. As a result, the outer shape of the insertion opening 10 also approaches a circle during the bending process while maintaining the connection with the insertion opening joint portion 210c.

[0108] Similar to the cross section of the insertion opening joint portion 210c before bending, the cross section of the intermediate portion 210b before bending also has a shape in which the dimension in the header pipe length direction gradually decreases outward in the header width direction.

[0109] However, the tensile stress and compressive stress acting on the end tube 210 due to the bending process differ depending on the position of the end tube 210 in the header-facing direction. That is, the farther the position is from the insertion port joint 210c, the smaller the tensile stress and compressive stress acting. In other words, the farther the position is from the insertion port joint 210c, the smaller the amount of plastic deformation due to the bending process.

[0110] Therefore, the rate of change in the header pipe length direction dimension in the header width direction (hereinafter referred to as the dimensional gradient) in the cross section of the intermediate portion 210b before bending is smaller than the dimensional gradient in the cross section of the insertion port joint portion 210c before bending. The cross section of the intermediate portion 210b also becomes closer to a circle due to plastic deformation associated with the bending.

[0111] The dimensional gradient in the cross section of the end tube 210 gradually decreases from the insertion opening joint 210c toward the base end 210a. In this way, the cross-sectional shape of the end tube 210 smoothly changes from the insertion opening joint 210c toward the base end 210a.

[0112] The base end 210a is hardly deformed during bending. For this reason, the cross-sectional shape of the base end 210a is circular before bending. The cross-sectional shape of the base end 210a after bending also remains circular.

[0113] According to the embodiment described above, the bending process causes the cross-sectional shape of the end tube 210 at various locations in the header-facing direction, typically at the insertion port joint 210c and the intermediate portion 210b, to approach a circle, specifically a perfect circle.

[0114] Generally, a tube with a circular cross section, especially a perfect circle, exhibits higher pressure resistance than a tube with the same tube thickness but a cross section of another shape. In other words, according to this embodiment, the pressure resistance of the end tube 210 is improved by undergoing bending processing, even if the tube thickness of the end tube 210 is not designed to be particularly thick. Since the tube thickness does not need to be particularly thick, the material cost required to manufacture the end tube 210 can be reduced.

[0115] This embodiment is applicable not only to the first embodiment but also to modifications 1-3 of the first embodiment.

[0116] 8 illustrates a configuration in which the center of the end tube 210 in the header width direction is positioned at the header imaginary center plane VP1. However, a configuration in which the center of the end tube 210 in the header width direction is positioned at a position different from the header imaginary center plane VP1 may also be employed. Specific examples thereof will be described below.

[0117] 10 shows the position of the end tube 210 in the header width direction according to this embodiment. To facilitate the following explanation, an end tube imaginary center plane VP3 is defined, which represents the position of the end tube 210 in the header width direction. The end tube imaginary center plane VP3 passes through the center of the end tube 210 in the header width direction and extends in the header pipe length direction and the header-facing direction.

[0118] In this embodiment, in the bending target portion 20 of the header pipe 100, the end pipe imaginary center plane VP3 is located more inward in the header width direction than the header imaginary center plane VP1 that coincides with the neutral plane VP2 of the bending. In other words, each end pipe 210 is brought closer to the inner end face 92.

[0119] Therefore, the maximum tensile stress acting on the end tube 210 during bending is reduced compared to the case where the configuration shown in Fig. 8 is adopted, and therefore breakage due to tensile stress is less likely to occur.

[0120] Specifically, in this embodiment, the outer edge RA_O of the end tube projection area RA in the header width direction is positioned inward in the header width direction from the header imaginary center plane VP1, which coincides with the neutral plane VP2 of bending. Therefore, this embodiment theoretically prevents tensile stress from acting on the end tube 210. In other words, the problem of breakage due to tensile stress is avoided. Since the end tube 210 can be thickened by compressive stress during bending, the pressure resistance of the end tube 210 can be improved.

[0121] 10 illustrates the header pipe 100 of the intermediate product 500I, but the header pipe 110 of the outdoor heat exchanger 500, which is obtained by bending the header pipe 100, also has a structure similar to that of the header pipe 100. This embodiment is also applicable not only to the above-mentioned Embodiments 1 and 2, but also to Modifications 1 to 3 of the above-mentioned Embodiment 1.

[0122] 11 , in this embodiment, in the bending target portion 20 of the header pipe 100, the end pipe imaginary center plane VP3 is positioned outward in the header width direction from the header imaginary center plane VP1 that coincides with the neutral plane VP2 of the bending. In other words, each end pipe 210 is brought closer to the outer end face 91.

[0123] Therefore, the maximum compressive stress acting on the end tube 210 during bending is reduced compared to the case where the configuration shown in Fig. 8 is adopted, and therefore breakage due to compressive stress is less likely to occur.

[0124] Specifically, in this embodiment, the inner edge RA_I of the end tube projection area RA in the header width direction is positioned outward in the header width direction from the header imaginary center plane VP1, which coincides with the neutral plane VP2 of bending. Therefore, this embodiment theoretically prevents compressive stress from acting on the end tube 210. In other words, the problem of breakage due to compressive stress is avoided.

[0125] 11 illustrates the header pipe 100 of the intermediate product 500I, but the header pipe 110 of the outdoor heat exchanger 500, which is obtained by bending the header pipe 100, also has a structure similar to that of the header pipe 100. This embodiment is also applicable not only to the above-mentioned Embodiments 1 and 2, but also to Modifications 1 to 3 of the above-mentioned Embodiment 1.

[0126] 10 and 11 are based on the premise that the positions of the end tubes 210 in the header width direction are aligned in the plurality of bend-portion-arranged heat transfer tubes 200C aligned in the header pipe length direction at the bend 21. The positions of the end tubes 210 in the header width direction do not have to be aligned in the plurality of bend-portion-arranged heat transfer tubes 200C. Specific examples of this are described below.

[0127] 12 shows the configuration of the bending portion 21 according to this embodiment. In this embodiment, the plurality of bending portion-arranged heat transfer tubes 200C arranged in the bending portion 21 are configured by a plurality of inner-arranged heat transfer tubes 200C_I arranged close to the inner end face 92 and a plurality of outer-arranged heat transfer tubes 200C_O arranged close to the outer end face 91.

[0128] In addition, in this embodiment, the multiple insertion ports 10 formed in the bent portion 21 of the header pipe 110 are composed of multiple insertion ports 10_I each positioned close to the inner end face 92 and multiple insertion ports 10_O each positioned close to the outer end face 91.

[0129] Each of the inwardly disposed heat transfer tubes 200C_I is connected to an insertion port 10_I disposed close to the inner end face 92. In order to clearly show the insertion port 10_I, Fig. 12 shows a portion of one inwardly disposed heat transfer tube 200C_I as a representative of the multiple inwardly disposed heat transfer tubes 200C_I.

[0130] Each of the outer heat transfer tubes 200C_O is connected to an insertion opening 10_O disposed close to the outer end face 91. In order to clearly show the insertion opening 10_O, Fig. 12 shows a portion of one outer heat transfer tube 200C_O as a representative of the multiple outer heat transfer tubes 200C_O.

[0131] The arrangement of each inwardly disposed heat transfer tube 200C_I in the header width direction is similar to the configuration shown in Fig. 10. That is, as shown in Fig. 10, the center of the end tube 210 of each inwardly disposed heat transfer tube 200C_I in the header width direction is located inward in the header width direction from the header imaginary center plane VP1.

[0132] On the other hand, the arrangement of each of the outer heat transfer tubes 200C_O in the header width direction is the same as the configuration shown in Fig. 11. That is, as shown in Fig. 11, the center of the end tube 210 of each of the outer heat transfer tubes 200C_O in the header width direction is located outward in the header width direction from the header imaginary center plane VP1.

[0133] The outer heat transfer tubes 200C_O and the inner heat transfer tubes 200C_I are arranged alternately in the length direction of the header pipe in the bend portion 21. That is, in this embodiment, the plurality of bend portion-arranged heat transfer tubes 200C are arranged in a staggered pattern when viewed in the header facing direction.

[0134] The effects of this embodiment are described below. As shown in Figures 10 and 11, the overall width of the end tube projection area RA in the header pipe length direction is greater than the overall width of the main body tube projection area RB in the header pipe length direction. Therefore, by arranging the multiple bend portion-located heat transfer tubes 200C in a staggered pattern, it is possible to arrange the bend portion-located heat transfer tubes 200C at a higher number density in the header pipe length direction than in a configuration in which all of the end tubes 210 are aligned in the header width direction at the bend portion 21.

[0135] Specifically, the pitch in the header pipe length direction between the inner heat transfer tube 200C_I and the adjacent outer heat transfer tube 200C_O can be made smaller than the outer dimension in the header pipe length direction of the end tube 210. Arranging the bend portion-arranged heat transfer tubes 200C at a high density in the header pipe length direction contributes to improving the efficiency of heat exchange.

[0136] 12 illustrates the header pipe 110 after bending, the header pipe 100 before bending also has a structure in which the outer heat transfer tubes 200C_O and the inner heat transfer tubes 200C_I are arranged alternately in the header pipe length direction, similar to the header pipe 110. Furthermore, this embodiment is applicable not only to the above-mentioned Embodiments 1 and 2, but also to Modifications 1 to 3 of the above-mentioned Embodiment 1.

[0137] 4 illustrates a header pipe 100 in which a single tubular body constitutes a bending target section 20 and a straight section 22. In this case, in the header pipe 100, the cross-sectional area of ​​the flow path constituted by the bending target section 20, taken perpendicular to the header pipe length direction (hereinafter simply referred to as the cross-sectional area), is equal to the cross-sectional area of ​​the flow path constituted by the straight section 22.

[0138] However, the header pipe 100 may be configured such that the cross-sectional area of ​​the flow path defined by the bending target section 20 is smaller than the cross-sectional area of ​​the flow path defined by the straight section 22. A specific example of this will be described below.

[0139] 13 , in the header pipe 100 of the intermediate product 500I according to this embodiment, the bending target portions 20 are configured to be thinner than the straight portions 22. Therefore, the dimension of the bending target portions 20 in the header width direction is smaller than the dimension of the straight portions 22 in the header width direction. In addition, the dimension of the bending target portions 20 in the header facing direction is smaller than the dimension of the straight portions 22 in the header facing direction.

[0140] In the bent portion-arranged heat transfer tube 200C, the dimension in the header width direction of the end tube 210 is smaller than the dimension in the header width direction of the main body tube 220. Therefore, it is possible to configure the bending target section 20 to which the end tube 210 is connected to be thinner than the straight section 22 to which the straight portion-arranged heat transfer tube 200S, which has the same structure as the main body tube 220, is connected.

[0141] In this embodiment, both the header width direction dimension of the end tube 210 in the bend portion-positioned heat transfer tube 200C and the header width direction dimension of the bending target section 20 to which the end tube 210 is connected are smaller than the header width direction dimension of the main body tube 220 in the bend portion-positioned heat transfer tube 200C.

[0142] Similarly, in the outdoor heat exchanger 500 obtained by bending the intermediate product 500I, the dimension of the bent portion 21 in the header width direction is smaller than the dimension of the straight portion 22 in the header width direction. Also, the dimension of the bent portion 21 in the header facing direction is smaller than the dimension of the straight portion 22 in the header facing direction.

[0143] In addition, both the header width direction dimension of the end tube 210 in the bend portion-positioned heat transfer tube 200C and the header width direction dimension of the bend portion 21 to which the end tube 210 is connected are smaller than the header width direction dimension of the main body tube 220 in the bend portion-positioned heat transfer tube 200C.

[0144] The effects of this embodiment will be described below. As described above, in this embodiment, the bending target portion 20 is configured to be thinner than the straight portion 22, and the dimension of the bending target portion 20 in the header width direction is smaller than the dimension of the straight portion 22 in the header width direction. Therefore, according to this embodiment, the bending stress generated in the bending target portion 20 during bending can be reduced compared to the cases of embodiments 1-5. Therefore, the intermediate product 500I is less likely to be damaged during bending.

[0145] Furthermore, since the bending stress generated in the bending target portion 20 during bending can be reduced more than in the case of embodiment 1 to 5, it is possible to make the radius of curvature of the bending portion 21 smaller than in the case of embodiment 1 to 5 without causing breakage due to the bending stress. In other words, it is possible to make the bending portion 21 more compact than in the case of embodiment 1 to 5.

[0146] In the outdoor heat exchanger 500, the heat exchange efficiency in the portion formed by the bent portion 21 and the bent portion-arranged heat transfer tube 200C is lower than the heat exchange efficiency in the portion formed by the straight portion 22 and the straight portion-arranged heat transfer tube 200S. Therefore, by making the bent portion 21 more compact and increasing the length of the straight portion 22, the heat exchange efficiency of the outdoor heat exchanger 500 as a whole can be improved.

[0147] 13 illustrates a header pipe 100 in which the straight section 22 is formed of a square tube and the bending target section 20 is formed of a circular tube that is thinner than the square tube that forms the straight section 22. Here, a square tube refers to a tubular body whose cross section perpendicular to the header pipe length direction is square, and a circular tube refers to a tubular body whose cross section perpendicular to the header pipe length direction is circular. However, the shapes of the cross sections perpendicular to the header pipe length direction of the tubular body that forms the straight section 22 and the tubular body that forms the bending target section 20 are not particularly limited.

[0148] Furthermore, this embodiment is applicable not only to the above-mentioned embodiment 1-5 but also to the above-mentioned modification 1-3 of embodiment 1.

[0149] The embodiment and modifications have been described above. The following modifications are also possible.

[0150] 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.

[0151] 5 and 9 show examples of header pipes 100 and 110 whose cross sections perpendicular to the header pipe length direction 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 the surface into which the heat transfer tube 200 is inserted being curved.

[0152] 5 and 9 show an example of the joint part 230. The joint part 230 may be any part capable of connecting the main body pipe 220 and the end pipe 210, and the shape of the joint part 230, the manufacturing method thereof, and the like are not particularly limited. The joint part 230 may be formed into a tubular shape. The joint part 230 may also be obtained by cutting a base material, or may be obtained by bonding together a plurality of members, specifically a plurality of plate-shaped members.

[0153] 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.

[0154] This application is based on Japanese Patent Application No. 2024-023583, filed on February 20, 2024. The entire specification, claims, and drawings of Japanese Patent Application No. 2024-023583 are incorporated herein by reference.

[0155] 10 Insertion port, 10_I Insertion port, 10_O Insertion port, 10C Insertion port, 20 Bending target portion, 21 Bending portion, 22 Straight portion (non-bending target portion), 91 Outer end surface, 92 Inner end surface, 100 Header pipe (intermediate product), 110 Header pipe, 110A First header pipe, 110B Second header pipe, 200 Heat transfer tube, 200a End, 200S Straight portion arranged heat transfer tube, 200C Bending portion arranged heat transfer tube, 200C_I Inner arranged heat transfer tube, 200C_O Outer arranged heat transfer tube, 200CC Bending portion arranged heat transfer tube, 210 End tube, 210a Base end, 210b Middle portion, 210c Insertion port joint (connection point), 220 Main body tube, 220a Outer tube, 220b Inner column, 220c flow path, 230 joint part, 300 fin, 500 outdoor heat exchanger (heat exchanger), 500I intermediate product, 600 air conditioning device, 610 compressor, 620 indoor heat exchanger, 630 expander, 640 four-way valve, 650 indoor fan, 660 outdoor fan, 671 first end piping, 672 second end piping, PP virtual plane, RA end pipe projection area, RB main body pipe projection area, RA_O end edge, RB_O end edge, RA_I end edge, RB_I end edge, VP1 header virtual center plane, VP2 bending neutral plane, VP3 end pipe virtual center plane.

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 product is The inside of the heat transfer tube is divided into a plurality of flow paths arranged in the header width direction perpendicular to the header facing direction and the header pipe length direction, by at least one inner column, It has the above inside, Among the multiple heat transfer tubes in the intermediate manufactured product, the heat transfer tube arranged in a bent section configuration in which the end is connected to the bent section of the first header tube and the second header tube that has been bent, A pair of end pipes forming one end and the other end, A main body tube is positioned between a pair of end tubes and constitutes the portion of the curved heat transfer tube that includes the center in the direction opposite the header, It has, Of the main body pipe and the pair of end pipes, only the main body pipe has the inner column. Heat exchanger manufacturing method.

2. 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 product is The inside of the heat transfer tube is divided into a plurality of flow paths arranged in the header width direction perpendicular to the header facing direction and the header pipe length direction, by at least one inner column, It has the above inside, Among the multiple heat transfer tubes in the intermediate manufactured product, the heat transfer tube arranged in a bent section configuration in which the end is connected to the bent section of the first header tube and the second header tube that has been bent, A pair of end pipes forming one end and the other end, A main body tube positioned between a pair of end tubes, which constitutes the portion of the curved heat transfer tube including the center in the direction opposite the header, the main body tube having the inner column, It has, The end edge of the end tube projection region obtained by perpendicularly projecting the end tube of the curved heat transfer tube onto a virtual plane extending perpendicularly in the direction opposite to the header is located inward in the direction of the radius of curvature in the header width direction, compared to the end edge of the main tube projection region obtained by perpendicularly projecting the main tube of the curved heat transfer tube onto the virtual plane, which the direction of the radius of curvature in the header width direction, compared to the end edge of the main tube projection region obtained by perpendicularly projecting the main tube of the curved heat transfer tube onto the virtual plane, Heat exchanger manufacturing method.

3. The cross-sectional shape of the end tube of the heat transfer tube with the bent section connected to the bending section is non-circular. Due to the plastic deformation of the end pipe and the part to be bent during the bending process, the shape of the cross-section of the connection point becomes closer to a circle. A method for manufacturing a heat exchanger according to claim 1 or 2.

4. Each of the first header tube and the second header tube in the aforementioned intermediate product is: A non-bending portion located adjacent to the bending portion in the longitudinal direction of the header conduit, It has, In each of the first header pipe and the second header pipe, The dimension of the portion to be bent in the header width direction is smaller than the dimension of the portion not to be bent in the header width direction. A method for manufacturing a heat exchanger according to claim 1 or 2.

5. In the heat transfer tube with a curved section, both the dimension of the end tube in the header width direction and the dimension of the bending target section to which the end tube is connected in the header width direction are smaller than the dimension of the main tube in the heat transfer tube with a curved section. A method for manufacturing a heat exchanger according to claim 1 or 2.

6. 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 inside of the heat transfer tube is divided into a plurality of flow paths arranged in the header width direction perpendicular to the header facing direction and the header pipe length direction, by at least one inner column, It has the above inside, Among the plurality of heat transfer tubes, the heat transfer tube arranged at the bends, whose ends are connected to the bends of the first and second header tubes, A pair of end pipes forming one end and the other end, A main body tube is positioned between a pair of end tubes and constitutes the portion of the curved heat transfer tube that includes the center in the direction opposite the header, It has, Of the main body pipe and the pair of end pipes, only the main body pipe has the inner column. heat exchanger.

7. 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 inside of the heat transfer tube is divided into a plurality of flow paths arranged in the header width direction perpendicular to the header facing direction and the header pipe length direction, by at least one inner column, It has the above inside, Among the plurality of heat transfer tubes, the heat transfer tube arranged at the bends, whose ends are connected to the bends of the first and second header tubes, A pair of end pipes forming one end and the other end, A main body tube positioned between a pair of end tubes, which constitutes the portion of the curved heat transfer tube including the center in the direction opposite the header, the main body tube having the inner column, It has, The outer edge of the end tube projection region obtained by perpendicularly projecting the end tube of the curved heat transfer tube onto a virtual plane extending perpendicularly in the direction opposite to the header is located inward with respect to the direction of the radius of curvature of the main tube projection region obtained by perpendicularly projecting the main tube of the curved heat transfer tube onto the virtual plane, with respect to the direction of the radius of curvature of the curve, compared to the outer edge of the main tube projection region obtained by perpendicularly projecting the main tube of the curved heat transfer tube onto the virtual plane. heat exchanger.

8. Of the main body pipe and the pair of end pipes, only the main body pipe has the inner column. The heat exchanger according to claim 7.

9. The inner edge of the end tube projection region with respect to the direction of the radius of curvature is located further outward than the inner edge of the main tube projection region with respect to the direction of the radius of curvature. The heat exchanger according to claim 7.

10. The maximum dimension in the header pipeline length direction of the end pipe projection region is greater than the maximum dimension in the header pipeline length direction of the main pipe projection region. The heat exchanger according to claim 7.

11. The center of the end pipe in the header width direction is located inward with respect to the direction of the radius of curvature of the bend, relative to the virtual center plane of the header that passes through the centers of the first header pipe and the second header pipe in the header width direction and extends in the direction of the header pipeline length. A heat exchanger according to any one of claims 6 to 10.

12. The center of the end pipe in the header width direction is located outward with respect to the direction of the radius of curvature of the bend, relative to the virtual center plane of the header that passes through the centers of the first header pipe and the second header pipe in the header width direction and extends in the direction of the header pipeline length. A heat exchanger according to any one of claims 6 to 10.

13. Multiple heat transfer tubes arranged in the curved section are connected to the curved section. The multiple heat transfer tubes with bent sections include: The end tube's center in the header width direction is located outward with respect to the direction of the radius of curvature of the bend, relative to the virtual center plane of the header that passes through the centers of the first and second header tubes in the header width direction and extends in the header pipeline length direction, and is an outward-arranged heat transfer tube. An inwardly positioned heat transfer tube in which the center of the end tube in the header width direction is located inward from the virtual center plane of the header with respect to the direction of the radius of curvature of the bend, It includes, In the curved section, the outwardly arranged heat transfer tubes and the inwardly arranged heat transfer tubes are arranged alternately in the direction of the header pipe length. A heat exchanger according to any one of claims 6 to 10.

14. Each of the first header tube and the second header tube is, A straight section located adjacent to the curved section in the longitudinal direction of the header conduit, and extending straight when viewed in the direction opposite the header, It has, In each of the first header pipe and the second header pipe, The dimension of the curved portion in the header width direction is smaller than the dimension of the straight portion in the header width direction. A heat exchanger according to any one of claims 6 to 10.

15. In the heat transfer tube with a curved section, both the dimension of the end tube in the header width direction and the dimension of the curve to which the end tube is connected in the header width direction are smaller than the dimension of the main tube in the heat transfer tube with a curved section. A heat exchanger according to any one of claims 6 to 10.

16. A heat exchanger according to any one of claims 6 to 10, 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.