HEADER PIPE, HEAT EXCHANGER, METHOD FOR MANUFACTURING HEADER PIPE, AND METHOD FOR MANUFACTURING HEAT EXCHANGER

TECHNICAL FIELD

[0001]The present disclosure relates to a header pipe, a heat exchanger, a method for manufacturing the header pipe, and a method for manufacturing the heat exchanger.

BACKGROUND ART

[0002]A heat exchanger is a component of a refrigeration circuit, and typically includes two header pipes and multiple heat transfer tubes connecting the two header pipes. One of the two header pipes is connected to a channel located upstream in the refrigeration circuit, and a refrigerant flows into the header pipe from upstream in the refrigeration circuit. The refrigerant flowing into the header pipe is distributed into the heat transfer tubes, and flows through the heat transfer tubes into the other of the header pipes. The refrigerant flowing into the other header pipe converges in the other header pipe. The other header pipe is connected to a channel located downstream in the refrigeration circuit, and the converged refrigerant flows out downstream in the refrigeration circuit.

[0003]While flowing through the heat transfer tubes, the refrigerant exchanges heat with ambient air. Thus, when the refrigerant flowing through the heat transfer tubes has a temperature higher than ambient air, the refrigerant is cooled. When the refrigerant flowing through the heat transfer tubes has a temperature lower than ambient air, the refrigerant is heated. The heat exchanger typically includes multiple heat transfer fins intersecting with and in thermal contact with the heat transfer tubes. The heat transfer fins increase the area of the heat exchanger for transferring heat to ambient air, and improve the heat exchange efficiency.

[0004]Patent Literature 1 describes a flat-tube evaporator that is an example of a heat exchanger. An inlet manifold included in the flat-tube evaporator corresponds to the upstream header pipe in the heat exchanger, and flat tubes correspond to the heat transfer tubes. A distribution tube including multiple orifices is inserted in the inlet manifold. The refrigerant flowing from upstream in the refrigeration circuit is guided by the distribution tube, flows out of the distribution tube through the orifices, and is guided into the flat tubes. The refrigerant flows through the flat tubes into an outlet manifold.

[0005]As described above, the header pipe included in the flat-tube evaporator described in Patent Literature 1 includes an outer tube connected to the heat transfer tubes, and an inner tube inserted in the outer tube and having multiple pores in the side surface. In the flat-tube evaporator described in Patent Literature 1, the refrigerant flowing into the outer tube is guided by the inner tube, flows out of the inner tube through the pores, and is guided into the flat tube. The refrigerant can thus be evenly distributed into the multiple heat transfer tubes.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

[0007]However, as illustrated in FIG. 4 in Patent Literature 1, the inner tube is cantilevered at one end of the outer tube. The position of the inner tube with respect to the outer tube is thus unstable. In particular, the inner tube may bend with heat from brazing and be displaced with respect to the outer tube in the process of manufacturing the header pipe outer tube. The inner tube displaced with respect to the outer tube changes the flow of the refrigerant in the header pipe and may not achieve designed performance.

[0008]In response to the above issue, an objective of the present disclosure is to provide a header pipe in which an inner tube is stably held by an outer tube, a heat exchanger including the header pipe, a method for manufacturing the header pipe, and a method for manufacturing the heat exchanger.

Solution to Problem

[0009]To achieve the above objective, a header pipe according to an aspect of the present disclosure includes an outer tube to which a plurality of heat transfer tubes are connected, an inner tube inserted in the outer tube and having a plurality of pores, and a plurality of supporters spaced from one another in a longitudinal direction of the outer tube and supporting the inner tube. A space between the inner tube and the outer tube includes a clearance for a refrigerant to flow in the header pipe through the plurality of supporters in a longitudinal direction of the header pipe.

Advantageous Effects of Invention

[0010]The structure according to the above aspect of the present disclosure includes the plurality of supporters, and the inner tube is supported by the outer tube with the supporters. In other words, the inner tube is supported at multiple points. The inner tube is thus stably held by the outer tube and is less likely to be displaced with respect to the outer tube.

BRIEF DESCRIPTION OF DRAWINGS

[0011]FIG. 1 is a front view of a heat exchanger according to an embodiment of the present disclosure including header pipes;

[0012]FIG. 2 is a cross-sectional view of each header pipe included in the heat exchanger in FIG. 1, illustrating the internal structure;

[0013]FIG. 3A is a cross-sectional view of the header pipe taken along line IIIA-IIIA in FIG. 2 as viewed in the direction indicated by the arrows;

[0014]FIG. 3B is a cross-sectional view of the header pipe taken along line IIIB-IIIB in FIG. 2 as viewed in the direction indicated by the arrows;

[0015]FIG. 4 is a cross-sectional view of the header pipe taken along line IV-IV in FIG. 2 as viewed in the direction indicated by the arrows;

[0016]FIG. 5A is a diagram illustrating a process of manufacturing the header pipe according to the embodiment of the present disclosure in time series;

[0017]FIG. 5B is a diagram illustrating the process of manufacturing the header pipe according to the embodiment of the present disclosure in time series;

[0018]FIG. 5C is a diagram illustrating the process of manufacturing the header pipe according to the embodiment of the present disclosure in time series;

[0019]FIG. 5D is a diagram illustrating the process of manufacturing the header pipe according to the embodiment of the present disclosure in time series;

[0020]FIG. 5E is a diagram illustrating the process of manufacturing the header pipe according to the embodiment of the present disclosure in time series;

[0021]FIG. 5F is a diagram illustrating the process of manufacturing the header pipe according to the embodiment of the present disclosure in time series;

[0022]FIG. 6A is a diagram illustrating a process of attaching a lid to a body in an outer tube in the header pipe according to the embodiment of the present disclosure in time series;

[0023]FIG. 6B is a diagram illustrating the process of attaching the lid to the body in the outer tube in the header pipe according to the embodiment of the present disclosure in time series;

[0024]FIG. 6C is a diagram illustrating the process of attaching the lid to the body in the outer tube in the header pipe according to the embodiment of the present disclosure in time series;

[0025]FIG. 7A is a plan view of a fixing member in the embodiment of the present disclosure, illustrating the details of the shape;

[0026]FIG. 7B is a plan view of a fixing member in a modification, illustrating the details of the shape;

[0027]FIG. 8 is a cross-sectional view of a header pipe according to a first modification, illustrating the internal structure;

[0028]FIG. 9 is a cross-sectional view of a header pipe according to a second modification, illustrating the internal structure;

[0029]FIG. 10A is a side view of an outer tube included in a header pipe according to a third modification, illustrating the outer shape;

[0030]FIG. 10B is a cross-sectional view of the outer tube taken along line X-X in FIG. 10A as viewed in the direction indicated by the arrows;

[0031]FIG. 10C is a plan view of the outer shape of a supporter included in the header pipe according to the third modification;

[0032]FIG. 10D is a diagram of the supporter in FIG. 10C attached to the outer tube in FIG. 10B;

[0033]FIG. 11A is a side view of an outer tube included in a header pipe according to a fourth modification, illustrating the outer shape;

[0034]FIG. 11B is a cross-sectional view of the outer tube taken along line XI-XI in FIG. 11A as viewed in the direction indicated by the arrows;

[0035]FIG. 11C is a plan view of a supporter included in the header pipe according to the fourth modification, illustrating the outer shape;

[0036]FIG. 11D is a diagram of the supporter in FIG. 11C attached to the outer tube in FIG. 11B;

[0037]FIG. 12A is a cross-sectional view of a body and the supporter taken along line XI-XIa in FIG. 11D as viewed in the direction indicated by the arrows, illustrating the shapes of fillets on a fit groove and a protrusion;

[0038]FIG. 12B is a cross-sectional view of a body and a supporter in another example taken similarly to FIG. 12A, illustrating the shapes of fillets on a fit groove and a protrusion;

[0039]FIG. 13A is a cross-sectional view of an outer tube in a modification of the embodiment of the present disclosure taken similarly to FIG. 3A; and

[0040]FIG. 13B is a cross-sectional view of an outer tube in another modification of the embodiment of the present disclosure taken similarly to FIG. 3A.

DESCRIPTION OF EMBODIMENTS

[0041]The structures and effects of a header pipe and a heat exchanger according to one or more embodiments of the present disclosure are described below with reference to the drawings. In the figures, like reference signs denote like or corresponding components.

Overall Structure of Heat Exchanger

[0042]FIG. 1 is a front view of a heat exchanger 1 according to an embodiment of the present disclosure including header pipes 2. As illustrated in FIG. 1, the heat exchanger 1 includes two header pipes 2 located parallel to each other, multiple heat transfer tubes 3 located between the two header pipes 2 to allow a refrigerant to flow between the two header pipes 2, and multiple heat transfer fins 4 intersecting with and in thermal contact with the multiple heat transfer tubes 3.

[0043]The heat exchanger 1 is a component of a refrigeration circuit (not illustrated). One of the two header pipes 2 is connected to a channel located upstream in the refrigeration circuit, and the refrigerant flows into the header pipe 2 from the channel. The refrigerant flowing into the header pipe 2 is distributed into the multiple heat transfer tubes 3, and flows through the heat transfer tubes 3 into the other of the header pipes 2. The other header pipe 2 is connected to a channel located downstream in the refrigeration circuit, and the refrigerant flowing into the other header pipe 2 flows out into the downstream channel.

[0044]While the refrigerant is flowing through the heat transfer tubes 3, air around the heat exchanger 1 and the refrigerant exchange heat with each other. The heat exchanger 1 including the multiple heat transfer fins 4 has a larger area for transferring heat to the air around the heat exchanger 1. The heat exchanger 1 thus has higher heat exchange efficiency.

Structure of Header Pipe

[0045]FIG. 2 is a cross-sectional view of each header pipe 2 included in the heat exchanger 1, illustrating the internal structure. As illustrated in FIG. 2, the header pipe 2 includes an outer tube 5 serving as an outer wall of the header pipe 2, and an inner tube 6 inserted in the outer tube 5. The inner tube 6 has, in side portions of the surface, multiple pores 6a extending through the surface. The pores 6a are arranged in two rows and at regular intervals in the longitudinal direction of the inner tube 6.

[0046]As illustrated in FIG. 2, the header pipe 2 includes two fixing members 7 spaced apart from each other in the longitudinal direction of the outer tube 5 to fix the portions of the inner tube 6 adjacent to the two ends to the outer tube 5. As described later, the fixing members 7 close gaps between the inner tube 6 and the outer tube 5. The fixing members 7 thus hermetically define a space between the inner tube 6 and the outer tube 5 in the longitudinal direction of the outer tube 5. The multiple pores 6a in the inner tube 6 are located between the two fixing members 7. The end of the inner tube 6 located on the right in the figure is closed.

[0047]As illustrated in FIG. 2, multiple supporters 8 are located between the inner tube 6 and the outer tube 5 in the space defined by the two fixing members 7. The supporters 8 are fixed to the outer tube 5 and support the inner tube 6.

[0048]As illustrated in FIG. 2, lids 9 are attached to the two ends of the outer tube 5 in the longitudinal direction. The lids 9 are fitted in the two ends of the outer tube 5 to hermetically close the two ends of the outer tube 5. The header pipe 2 includes an extraction pipe 10. The refrigerant flowing into and out of the header pipe 2 flows into and out of the outer tube 5 through the extraction pipe 10.

[0049]As described above, the inner tube 6 is supported by the outer tube 5 with the multiple fixing members 7 and the multiple supporters 8, and is thus stably held by the outer tube 5 in the header pipe 2. The inner tube 6 is thus less likely to be displaced in a process of manufacturing the header pipe 2 described later. This structure thus facilitates the manufacture of the header pipe 2 and stabilizes the performance of the header pipe 2.

[0050]When the header pipe 2 is connected to a channel located upstream from the header pipe 2 in the refrigeration circuit (not illustrated), the refrigerant flowing from the upstream channel flows through the extraction pipe 10 into a space between one of the lids 9 and one of the fixing members 7 located on the left in FIG. 2. The refrigerant flowing into the space between the lid 9 and the fixing member 7 then flows into the inner tube 6. The refrigerant flowing into the inner tube 6 passes through the multiple pores 6a in the inner tube 6 and is distributed into the multiple heat transfer tubes 3. The refrigerant then flows through the heat transfer tubes 3 into the other header pipe 2.

[0051]The refrigerant flowing into the other header pipe 2 through the heat transfer tubes 3 flows into the inner tube 6 in the other header pipe 2 through the multiple pores 6a in the inner tube 6. The refrigerant flowing into the inner tube 6 flows into the space between the lid 9 and the fixing member 7 located on the left in FIG. 2 in the other header pipe 2, and then flows through the extraction pipe 10 into the channel located downstream from the header pipe 2 in the refrigeration circuit (not illustrated).

Structure of Fixing Member

[0052]FIG. 3A is a cross-sectional view of the header pipe 2 taken along a plane indicated by line IIIA-IIIA in FIG. 2. FIG. 3B is a cross-sectional view of the header pipe 2 taken along a plane indicated by line IIIB-IIIB in FIG. 2. As illustrated in FIGS. 3A and 3B, each fixing member 7 closes the entire gap between the inner tube 6 and the outer tube 5. The inner tube 6 extends through each fixing member 7. Each fixing member 7 is brazed to the inner tube 6 and the outer tube 5. The brazing material closes fine gaps between the fixing member 7 and the inner tube 6 and between the fixing member 7 and the outer tube 5. The fixing members 7 thus hermetically define the space between the inner tube 6 and the outer tube 5 in the longitudinal direction of the outer tube 5.

[0053]As illustrated in FIGS. 3A and 3B, the outer tube 5 includes a combination of a body 5a having a U-shaped cross section and a bottom plate 5b closing the open end of the body 5a in the U-shaped cross section.

Structure of Supporter

[0054]FIG. 4 is a cross-sectional view of the header pipe 2 taken along a plane indicated by line IV-IV in FIG. 2. As illustrated in FIG. 4, each supporter 8 is located between the inner tube 6 and the outer tube 5 to support the inner tube 6. The inner tube 6 extends through each supporter 8.

[0055]As illustrated in FIG. 4, a first clearance 8a is defined between each supporter 8 and the outer tube 5. When the header pipe 2 is viewed in plan in the longitudinal direction of the header pipe 2, all portions of the heat transfer tubes 3 protruding into the outer tube 5 are viewable in the first clearance 8a. This structure prevents the supporters 8 and the heat transfer tubes 3 from interfering with one another. Additionally, the flow of the refrigerant flowing into and out of the heat transfer tubes 3 is less likely to be affected by the supporters 8.

[0056]As illustrated in FIG. 4, second clearances 8b are defined between the inner tube 6 and each supporter 8. The second clearances 8b are symmetrically located on two portions of the inner tube 6. The second clearances 8b are located with the pores 6a facing the second clearances 8b. The supporter 8 thus does not close the pores 6a when overlapping the pores 6a. The attaching positions of the supporters 8 can thus be selected independently of the positions of the pores 6a.

[0057]With the first clearance 8a between each supporter 8 and the outer tube 5, and the second clearances 8b between the supporter 8 and the inner tube 6, the refrigerant can flow through the supporters 8 in the longitudinal direction of the header pipe 2 in the space between the inner tube 6 and the outer tube 5.

[0058]When the inner tube 6 in FIG. 4 is compared to a clockface, the pores 6a are arranged in two rows at positions substantially corresponding to four and eight, but the positions are examples. The positions of the pores 6a may be selected as appropriate for the design. The number of pores 6a illustrated in FIG. 4 may also be selected as appropriate for the design. In other words, in FIG. 4, the pores 6a may be arranged in three rows or in one row. The positions and the number of second clearances 8b may be selected as appropriate based on the positions and the number of pores 6a.

Method for Manufacturing Header Pipe and Method for Manufacturing Heat Exchanger

[0059]FIGS. 5A to 5F are diagrams illustrating processes of manufacturing the header pipe 2 in time series. A method for manufacturing the header pipe 2 is described below with reference to FIGS. 5A to 5F.

[0060]The components of the header pipe 2 are manufactured separately. In other words, each of the body 5a and the bottom plate 5b included in the outer tube 5 is manufactured by bending a piece of material cut out from a metal plate. The inner tube 6 is manufactured by cutting a metal pipe and forming the pores 6a in the metal pipe. Each of the fixing members 7, the supporters 8, and the lids 9 is cut out from a metal plate. The extraction pipe 10 is manufactured by cutting a metal pipe and bending the metal pipe. A brazing material is applied to portions of each component as appropriate.

Fixing Member Fixing Process

[0061]When the components are prepared as described above, the inner tube 6 is inserted into one of the fixing members 7 as illustrated in FIG. 5A. The inner tube 6 is positioned with respect to the fixing member 7 with the pores 6a facing in predetermined directions, or in other words, in the directions illustrated in FIG. 3A. As illustrated in FIG. 5B, a tube expander 11 is then placed into the inner tube 6 to expand a portion of the inner tube 6 intersecting with the fixing member 7. This fixes the inner tube 6 to the fixing member 7 as illustrated in FIG. 5B. The inner tube 6 is fixed to the fixing member 7 with the pores 6a facing in predetermined directions, or in other words, in the directions illustrated in FIG. 3A.

Inner Tube Attachment Process

[0062]As illustrated in FIG. 5C, the supporters 8 and the other fixing member 7 are attached to the inner tube 6 after the fixing member fixing process. With the second clearances 8b left in the supporters 8, the supporters 8 can be arranged without avoiding the pores 6a in the inner tube 6. This improves work efficiency.

Overall Assembly Process

[0063]The inner tube 6 after the inner tube attachment process, or more specifically, the inner tube 6 to which the fixing members 7 and the supporters 8 are attached is attached to the body 5a as illustrated in FIG. 5D. The inner tube 6 fixed to one of the fixing members 7 in the fixing member fixing process does not rotate about the central axis of the inner tube 6 relative to the fixing member 7 before or after the inner tube attachment process. The inner tube 6 is thus attached to the body 5a while remaining the orientation illustrated in FIG. 5B in the inner tube attachment process. As illustrated in FIG. 5D, the body 5a has many comb teeth 5c. The effects of the teeth 5c are described later.

[0064]As illustrated in FIG. 5E, the lids 9 are then attached to the two ends of the body 5a. Finally, as illustrated in FIG. 5F, the bottom plate 5b and the extraction pipe 10 are attached to the body 5a. The assembly of the header pipe 2 is thus complete.

Procedure of Attaching Bottom Plate

[0065]FIGS. 6A to 6C are diagrams illustrating, in time series, a process of attaching the bottom plate 5b to the body 5a in the outer tube 5 in the above overall assembly process. As illustrated in FIG. 6A, the teeth 5c extend straight before the bottom plate 5b is attached to the body 5a. This allows the bottom plate 5b to be inserted into the body 5a as illustrated in FIG. 6B. After the bottom plate 5b is inserted into the body 5a, the teeth 5c are bent as illustrated in FIG. 6C. When the teeth 5c are bent, the bottom plate 5b is held between each fixing member 7 and the teeth 5c. The bottom plate 5b is thus fixed to the body 5a.

Final Assembly Process of Heat Exchanger

[0066]Once assembled, the two header pipes 2 are arranged in parallel to each other at an interval. The multiple heat transfer tubes 3 are arranged between the two header pipes 2 and attached to the two header pipes 2. The multiple heat transfer fins 4 are attached to the heat transfer tubes 3 to intersect with the heat transfer tubes 3. The heat exchanger 1 is thus assembled as illustrated in FIG. 1.

Brazing Process

[0067]After assembled as illustrated in FIG. 1 in the final assembly process, the heat exchanger 1 is placed in a furnace (not illustrated) and heated. When the heat exchanger 1 is heated, a brazing material pre-applied to the components of the heat exchanger 1 melts and flows into fine gaps between the components. The heat exchanger 1 is then cooled to set the brazing material. Brazing is thus complete.

[0068]The header pipes 2 and the heat exchanger 1 including the header pipes 2 are manufactured with the above processes.

Details of Shape of Fixing Member

[0069]Details of the shape of the fixing members 7 included in each header pipe 2 illustrated in FIG. 2, and a modification of the fixing members 7 are described. FIG. 7A is a plan view of each fixing member 7 included in the header pipe 2 in FIG. 2, illustrating the details of the shape. FIG. 7B is a plan view of a fixing member 7 according to a modification, illustrating the details of the shape.

[0070]As illustrated in FIG. 7A, each fixing member 7 has an insertion hole 7a through which the inner tube 6 extends. The insertion hole 7a has a planar shape similar to the cross section of the inner tube 6. In other words, when the inner tube 6 has a circular cross section, the insertion hole 7a has a circular planar shape. As illustrated in FIG. 7A, the planar shape of the insertion hole 7a is slightly larger than the cross section of the inner tube 6 before tube expansion. The inner tube 6 is thus easily inserted into the insertion hole 7a before tube expansion. The inner tube 6 comes in close contact with the fixing member 7 when expanded.

[0071]As illustrated in FIG. 7B, the insertion hole 7a may have a planar shape dissimilar to the cross section of the inner tube 6. When the insertion hole 7a has a planar shape dissimilar to the cross section of the inner tube 6, some portions of the fixing member 7 are further fitted into the inner tube 6 when the inner tube 6 is expanded, and fix the inner tube 6 to the fixing member 7 more firmly. This restricts the rotation of the inner tube 6 about the longitudinal axis relative to the fixing member 7 more reliably.

First and Second Modifications

[0072]FIG. 8 is a cross-sectional view of a header pipe 2 according to a first modification. FIG. 9 is a cross-sectional view of a header pipe 2 according to a second modification.

[0073]Although each header pipe 2 described above includes the fixing members 7 and the extraction pipe 10, the header pipe 2 is not limited to a header pipe including the fixing members 7 or the extraction pipe 10. For example, as illustrated in FIG. 8, one end of the inner tube 6 may protrude leftward in the figure through the lid 9 to the outside of the header pipe 2. For example, as illustrated in FIG. 9, one end of the inner tube 6 may be bent into an L shape to protrude from the header pipe 2 through the outer tube 5. In the examples, the refrigerant can directly flow into and out of the header pipe 2 through the inner tube 6. This eliminates the extraction pipe 10. This also eliminates the fixing members 7. Thus, as illustrated in FIGS. 8 and 9, the multiple supporters 8 alone are located at intervals in the longitudinal direction of the outer tube 5 between the lids 9 attached to the two ends of the outer tube 5.

[0074]Although the inner tube 6 described above is expanded to be fixed to the fixing members 7, the end portion of the inner tube 6 located on the right in FIGS. 8 and 9 may be expanded to be fixed to the rightmost supporter 8 in the examples in FIGS. 8 and 9.

Third Modification

[0075]FIG. 10A is a side view of an outer tube 5 included in a header pipe 2 (not illustrated in FIG. 10A) according to a third modification, illustrating the outer shape. FIG. 10B is a cross-sectional view of the outer tube 5 taken along a plane indicated by line X-X in FIG. 10A. FIG. 10C is a plan view of a supporter 8 included in the header pipe 2 according to the third modification, illustrating the outer shape. FIG. 10D is a diagram of the supporter 8 in FIG. 10C attached to the outer tube 5 in FIG. 10B.

[0076]As illustrated in FIGS. 10A and 10B, a body 5a in the outer tube 5 has fit grooves 5d in the two side surfaces. As illustrated in FIG. 10C, each supporter 8 includes protrusions 8c. As illustrated in FIG. 10A, the fit grooves 5d extend upward from lower ends of the body 5a. This allows the protrusions 8c to be inserted from the bottom of the body 5a to be fitted into the fit grooves 5d. As illustrated in FIG. 10B, the fit grooves 5d extend through the body 5a. Thus, when the protrusions 8c are fitted to the fit grooves 5d, the end of each protrusion 8c protrudes to the outside of the body 5a. When the protrusions 8c are fitted to the fit grooves 5d, the supporter 8 is fixed to the body 5a in the manner illustrated in FIG. 10D.

[0077]As described above, in the header pipe 2 according to the third modification, the body 5a in the outer tube 5 includes the fit grooves 5d, and the supporters 8 include the protrusions 8c to be fitted into the fit grooves 5d. The supporters 8 can thus be easily positioned with respect to the body. This structure facilitates the assembly of the header pipe 2. This structure also improves the assembling accuracy of the header pipe 2. With the ends of the protrusions 8c protruding to the outside of the body 5a when the header pipe 2 is assembled, the supporters 8 are easily determined as being attached from outside the outer tube 5.

[0078]Although the supporters 8 include the protrusions 8c in the above example, components other than the supporters 8 may include protrusions to be fitted into the fit grooves 5d. Each fixing member 7 or each lid 9 may instead include protrusions to be fitted to the fit grooves 5d.

Fourth Modification

[0079]FIG. 11A is a side view of an outer tube 5 included in a header pipe 2 (not illustrated in FIG. 11A) according to a fourth modification, illustrating the outer shape. FIG. 11B is a cross-sectional view of the outer tube 5 taken along a plane indicated by line XI-XI in FIG. 11A. FIG. 11C is a plan view of a supporter 8 included in the header pipe 2 according to the fourth modification, illustrating the outer shape. FIG. 11D is a diagram of the supporter 8 in FIG. 11C attached to the outer tube 5 in FIG. 11B.

[0080]The header pipe 2 according to the fourth modification includes the same basic components as and has the same effects as the header pipe 2 according to the third modification. However, the header pipe 2 according to the fourth modification differs from the header pipe 2 according to the third modification in that the bottom plate 5b has second fit grooves 5e as illustrated in FIGS. 11A and 11B, and in that the protrusions 8c included in each supporter 8 are fitted in the second fit grooves 5e in addition to the fit grooves 5d.

[0081]In the header pipe 2 according to the fourth modification, after each supporter 8 is positioned with respect to the body 5a by fitting the protrusions 8c into the fit grooves 5d, the bottom plate 5b can be positioned with respect to the body 5a by fitting the protrusions 8c into the second fit grooves 5e. Thus, the bottom plate 5b can be easily and accurately positioned with respect to the body 5a. This structure further facilitates the assembly of the header pipe 2. This structure further improves the assembling accuracy of the header pipe 2 as well. Although each supporter 8 described in the above example includes the protrusions 8c to be fitted into the fit grooves 5d and the second fit grooves 5e, components other than the supporters 8 may include protrusions to be fitted into the fit grooves 5d and the second fit grooves 5e. Each fixing member 7 or each lid 9 may include protrusions to be fitted into the fit grooves 5d and the second fit grooves 5e.

[0082]In the third and fourth modifications as well, each of the body 5a and the bottom plate 5b is manufactured by bending a piece of material cut out from a metal plate. When the material has the fit grooves 5d and the second fit grooves 5e formed before bending, and is bent with insufficient accuracy or deformed after bending, the positions of the fit grooves 5d or the second fit grooves 5e located on the right in the outer tube 5 in FIG. 10B or 11B may be misaligned with the positions of the fit grooves 5d or the second fit grooves 5e located on the left in the outer tube 5 in FIG. 10B or 11B. Thus, for example, when each protrusion 8c is fitted into the right fit groove 5d in the body 5a in FIG. 10B, a gap may be left between the protrusion 8c and the left fit groove 5d in the body 5a. For example, when the protrusion 8c is fitted into the left second fit groove 5e in the bottom plate 5b in FIG. 11B, a gap may be left between the protrusion 8c and the right second fit groove 5e in the bottom plate 5b. Thus, the fit grooves 5d and the second fit grooves 5e may be formed after the piece of material is bent. Forming the fit grooves 5d and the second fit grooves 5e after bending the piece of material can reduce misalignment between the right and left fit grooves 5d or between the right and left second fit grooves 5e.

[0083]FIG. 12A is a cross-sectional view of the body 5a and each supporter 8 taken along a plane indicated by line XIa-XIa in FIG. 11D, illustrating fillets on the fit groove 5d and the protrusion 8c. FIG. 12B is a cross-sectional view of the body 5a and each supporter 8 in another example taken similarly to FIG. 12A, illustrating the shapes of the fillets on the fit groove 5d and the protrusion 8c.

[0084]As described above, in the third and fourth modifications, the ends of the protrusions 8c in each supporter 8 protrude to the outside of the outer tube 5 when the supporter 8 is attached to the outer tube 5. Thus, when the supporter 8 is brazed to the outer tube 5, fillets 12 are formed inside and outside the outer tube 5 as illustrated in FIG. 12A. This improves the strength of brazed portions. This also easily improves the airtightness and watertightness of the brazed portions.

[0085]Each protrusion 8c may have a shape and dimensions with which the end of the protrusion 8c does not reach the outer surface of the outer tube 5. In other words, as illustrated in FIG. 12B, each supporter 8 attached to the outer tube 5 may have the end of each protrusion 8c within the fit groove 5d. In this case, as illustrated in FIG. 12B, the fillets 12 are formed inside the outer tube 5 and on inner portions of the fit groove 5d. This improves the strength of brazed portions. This also easily improves the airtightness and watertightness of the brazed portions.

Shape of Outer Tube in Modifications

[0086]FIG. 13A is a cross-sectional view of an outer tube 5 in a modification taken similarly to FIG. 3A. FIG. 13B is a cross-sectional view of an outer tube 5 in another modification taken similarly to FIG. 3A.

[0087]Although the body 5a in the outer tube 5 described above with reference to FIGS. 3A and 3B has a U-shaped cross section, the body 5a may have any grooved cross section other than the cross section illustrated in FIGS. 3A and 3B. For example, the body 5a may have a cross section illustrated in FIG. 13A or 13B. In other words, as illustrated in FIG. 13A, the cross section of the body 5a may have a rectilinear outer shape with two corners 5f each having a right interior angle. As illustrated in FIG. 13B, the cross-section of the body 5a may have four corners 5f each having an obtuse interior angle.

[0088]In embodiments of the present disclosure, a grooved cross section refers to a cross section with a shape in which ends in three directions are closed and an end is open. The open end of the grooved cross section is closed when another component is attached to the open end. In other words, a grooved cross section in embodiments of the present disclosure refers to a cross section with an open end that is closed when another component is attached to the open end. The grooved crossed section in embodiments of the present disclosure may have any shape at the closed ends in three directions. The cross section of the body in embodiments of the present disclosure is changeable as appropriate to any grooved cross section described above. A grooved cross section also includes a cross section typically referred to as an angular U shape or a C shape.

[0089]The cross section of the bottom plate in embodiments of the present disclosure is not limited to the cross section of the bottom plate 5b illustrated in FIGS. 3A, 3B, 13A, or 13B or other figures. The cross section of the bottom plate in embodiments of the present disclosure is changeable as appropriate to any cross section with which the bottom plate closes the grooved cross section of the body when attached to the open end of the body.

[0090]As described above, in each header pipe 2, the inner tube 6 is supported by the outer tube 5 with the multiple supporters 8 arranged in the longitudinal direction of the inner tube 6 or with the multiple fixing members 7 and supporters 8. In other words, the inner tube 6 is supported by the outer tube 5 at multiple points. Thus, the inner tube 6 is more stably held by the outer tube 5 than the inner tube cantilevered at the outer tube as in the example described in Patent Literature 1. The inner tube 6 is thus less likely to be bent and is less likely to be displaced with respect to the outer tube 5 in the process of manufacturing the header pipe 2. This structure thus facilitates the manufacture of the header pipe 2. This structure also improves the accuracy of the shape of the header pipe 2, stabilizing the performance of the header pipe 2.

[0091]In the header pipe 2, the first clearance 8a is defined between the outer tube 5 and each supporter 8, and the second clearances 8b are defined between the inner tube 6 and the supporter 8. Thus, the refrigerant can travel through the supporters 8 in the longitudinal direction of the header pipe 2 in the space between the outer tube 5 and the inner tube 6. The refrigerant can thus evenly flow through many heat transfer tubes 3. This improves the performance of the heat exchanger 1.

[0092]However, the technical scope of the present disclosure is not limited to the above embodiments. The present disclosure may be freely applied, modified, or varied within the scope of the technical ideas described in the scope of the claims.

[0093]Specific mechanical structures of the heat exchanger 1 and the header pipe 2 according to the above embodiments are examples, and do not limit the technical scope of the present disclosure. In particular, the number of supporters included in the header pipe according to embodiments of the present disclosure is not limited to the example described above.

[0094]For example, the header pipes 2 described above are located in parallel to each other. However, the header pipes 2 may not be located in parallel to each other. The header pipes 2 may have any outer shape as well.

[0095]In the above embodiments, the inner tube 6 has a perfect circle cross section. However, a header pipe according to embodiments of the present disclosure is not limited to an inner tube with a perfect circle cross section. The inner tube included in the header pipe according to embodiments of the present disclosure may be a square tube or a tube with another cross section.

[0096]In the above embodiments, the two ends of the inner tube 6 are fixed to the outer tube 5 with the two fixing members 7, and the supporters 8 fixed to the outer tube 5 and supporting the inner tube 6 are located between the two fixing members 7. However, the inner tube 6 may be fixed to the outer tube 5 with three or more fixing members 7. In this case, the fixing member 7 located in the middle may have clearances facing the pores 6a similarly to the second clearances 8b in the supporters 8. The inner tube 6 may be fixed at portions other than the ends.

[0097]When the supporters 8 have a thickness sufficiently smaller than the diameter of the pores 6a, the refrigerant can pass through the pores 6a with the supporters 8 overlapping the pores 6a. This structure may eliminate the second clearances 8b. The pores 6a may have a cross section other than a circle. The pores 6a may have an oblong or polygonal cross section. The pores 6a may have any diameter. Although the pores 6a in the above example are arranged linearly at regular intervals, the pores 6a may be arranged at irregular intervals. The pores 6a may be located at pseudorandom positions.

[0098]In the above embodiments, the heat exchanger 1 includes the heat transfer fins 4. However, the heat exchanger according to embodiments of the present disclosure is not limited to components corresponding to the heat transfer fins 4. The heat exchanger according to embodiments of the present disclosure may or may not include components corresponding to the heat transfer fins 4. The heat exchanger according to embodiments of the present disclosure includes at least components corresponding to the header pipes 2 and the heat transfer tubes 3.

[0099]In embodiments of the present disclosure, the header pipes and the heat exchanger may be formed from any materials. The materials may be selected as appropriate based on the purpose of use, the use environment, or the intended performance. The components of the header pipes and the heat exchanger according to embodiments of the present disclosure may be processed with any method or any means.

[0100]Various aspects of the present disclosure are described below as appendixes.

Appendix 1

Appendix 2

Appendix 3

Appendix 4

Appendix 5

Appendix 6

Appendix 7

Appendix 8

Appendix 9

Appendix 10

Appendix 11

Appendix 12

Appendix 13

Appendix 14

[0152]The foregoing describes some example embodiments for explanatory purposes. Although the foregoing discussion has presented specific embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the broader spirit and scope of the invention. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. This detailed description, therefore, is not to be taken in a limiting sense, and the scope of the invention is defined only by the included claims, along with the full range of equivalents to which such claims are entitled.

[0153]This application claims the benefit of Japanese Patent Application No. 2022-207144, filed on Dec. 23, 2022, the entire disclosure of which is incorporated by reference herein.

INDUSTRIAL APPLICABILITY

[0154]The technique according to one or more embodiments of the present disclosure is useful for a header pipe, a heat exchanger, a method for manufacturing the header pipe, and a method for manufacturing the heat exchanger.

REFERENCE SIGNS LIST