Distributor, heat exchanger, method for manufacturing distributor, and method for manufacturing heat exchanger

Abstract

A distributor (1A) comprises an inner tube (10A) having an orifice (11) on an outer peripheral surface thereof, a refrigerant flowing out of the orifice; and an outer tube (20A) the inner diameter of which is larger than the outer diameter of the inner tube (10A) and which accommodates the inner tube (10A) in an internal space formed by the inner peripheral surface of the outer tube, in a state in which the inner peripheral surface surrounds the outer peripheral surface of the inner tube (10A). A plurality of refrigerant pipes, joined by a brazing material and through which refrigerant is distributed, are connected to the outer tube (20A), and an opposing portion of the inner peripheral surface of the outer tube (20A) that faces the orifice (11) is formed of a material with a melting point higher than that of the brazing material.

Description

Distributor, heat exchanger, distributor manufacturing method, and heat exchanger manufacturing method

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

[0002] In some distributors, an inner pipe is housed in an outer pipe, and the inner pipe has orifices on its outer periphery that allow the refrigerant to flow out, in order to distribute the refrigerant evenly.

[0003] For example, Patent Document 1 discloses a distributor that includes a cylindrical inner tube having an orifice, and a cylindrical outer tube that houses the inner tube.

[0004] Patent Document 2 discloses a distributor that includes two cylindrical inner pipes each having an orifice and a rectangular outer pipe that houses the two inner pipes.

[0005] JP 2005-180910 A International Publication No. 2023 / 062800

[0006] In the distributors described in Patent Documents 1 and 2, the distributor components are assembled and then brazed to join them. In this process, if the inner tube is sufficiently long, the center of the inner tube in the axial direction may bend and come into contact with the inner wall of the outer tube. Furthermore, if the outer tube is manufactured by joining two components, the portion of the inner tube that is in contact with the inner wall of the outer tube may come into contact with the brazing material used to braze the joint. As a result, the orifice may be blocked by the brazing material.

[0007] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a distributor, a heat exchanger, a method for manufacturing a distributor, and a method for manufacturing a heat exchanger in which the orifice is prevented from being blocked by brazing material.

[0008] To achieve the above object, the distributor according to the present disclosure includes an inner pipe having an orifice on its outer circumferential surface from which a refrigerant flows, and an outer pipe having an inner diameter larger than the outer diameter of the inner pipe and containing the inner pipe in an internal space defined by the inner circumferential surface, with the inner circumferential surface surrounding the outer circumferential surface of the inner pipe. A plurality of refrigerant pipes are connected to the outer pipe, and the refrigerant is distributed through the outer pipe, and the outer pipe is joined with a brazing material. Furthermore, the inner circumferential surface of the outer pipe facing the orifice is made of a material with a melting point higher than that of the brazing material.

[0009] According to the configuration of the present disclosure, the facing portion of the inner circumferential surface of the outer tube facing the orifice is formed of a material with a melting point higher than that of the brazing material. Therefore, the facing portion does not melt during brazing, and the material of the facing portion does not function as the brazing material. As a result, even if the inner tube bends and the orifice comes into contact with the facing portion, the orifice is prevented from being blocked by the brazing material.

[0010] 2A and 2B are cross-sectional views of a main body portion of an outer tube when assembling a heat transfer tube, a fin, and an inner tube in a method for manufacturing a heat exchanger including a distributor according to embodiment 1 of the present disclosure; sectional views of a main body portion of an outer tube when lightly press-fitting a cover portion in a method for manufacturing a heat exchanger including a distributor according to embodiment 1 of the present disclosure; sectional views of a distributor according to embodiment 2 of the present disclosure; sectional views of a modified distributor according to embodiment 2 of the present disclosure; sectional views of another modified distributor according to embodiment 2 of the present disclosure; sectional views of a distributor according to embodiment 3 of the present disclosure; sectional views of a modified distributor according to embodiment 3 of the present disclosure; sectional views of another modified distributor according to embodiment 3 of the present disclosure; sectional views of yet another modified distributor according to embodiment 3 of the present disclosure; a cross-sectional view of a brazing jig used in a brazing step provided in a modified method for manufacturing a distributor according to embodiment 1 of the present disclosure, and a cross-sectional view of a main body portion and a cover portion fixed by the brazing jig; an enlarged front view showing an example of an attachment position of a brazing jig used in a brazing step provided in a modified method for manufacturing a distributor according to embodiment 1 of the present disclosure; an enlarged front view showing another example of an attachment position of a brazing jig used in a brazing step provided in a modified method for manufacturing a distributor according to embodiment 1 of the present disclosure; an enlarged front view showing an example of a brazing jig used in a brazing step provided in a modified method for manufacturing a distributor according to embodiment 1 of the present disclosure; an enlarged front view showing another example of a brazing jig used in a brazing step provided in a manufacturing method for a modified distributor according to embodiment 1 of the present disclosure; an enlarged front view showing yet another example of a brazing jig used in a brazing step provided in a manufacturing method for a modified distributor according to embodiment 1 of the present disclosure;

[0011] Hereinafter, a distributor, a heat exchanger, a distributor manufacturing method, and a heat exchanger manufacturing method according to embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, identical or equivalent parts are designated by the same reference numerals. In addition, in the Cartesian coordinate system XYZ shown in the drawings, the extension direction of the distributor cylinder is the left-right direction, and the extension direction of the heat transfer tubes connected to the distributor is the up-down direction. The left-right direction is the X-axis, the up-down direction is the Z-axis, and the direction perpendicular to the X-axis and Z-axis is the Y-axis. This coordinate system will be referenced as appropriate below.

[0012] (Embodiment 1) A distributor according to embodiment 1 is a distributor in which an inner tube having an orifice through which a refrigerant flows out is housed in an outer tube connected to a heat transfer tube. In this distributor, to prevent the orifice from being clogged with brazing material during brazing during manufacturing, the inner circumferential surface of the outer tube is formed of a material that does not melt when heated during brazing. First, with reference to FIG. 1, the configuration of a heat exchanger incorporating this distributor will be described, followed by the configuration of the distributor and a method for manufacturing the distributor.

[0013] Fig. 1 is a perspective view of a heat exchanger 100 including a distributor 1A according to embodiment 1. For ease of understanding, Fig. 1 shows only the heat transfer tubes 3 and fins 4 in a portion of the heat exchanger 100, and omits the heat transfer tubes 3 and fins 4 in other portions.

[0014] As shown in FIG. 1, the heat exchanger 100 includes distributors 1A and 2A for distributing and collecting a refrigerant, a plurality of heat transfer tubes 3 connected to the distributors 1A and 2A and through which the refrigerant flows, and a plurality of fins 4 attached to the heat transfer tubes 3.

[0015] The distributors 1A and 2A are formed in the shape of a square tube with rounded corners. Although not shown in Fig. 1, the internal space of the square tube of the distributors 1A and 2A forms a flow path for the refrigerant to flow. The distributors 1A and 2A also have cylindrical connectors 5 and 6 shown in Fig. 1, to which connecting pipes of external equipment (not shown) that supply and discharge the refrigerant are connected. When the external equipment is connected to the distributors 1A and 2A, the refrigerant flows through the flow path in the internal space.

[0016] 1, the distributors 1A and 2A are arranged spaced apart from each other in the vertical direction with their tube axes A1 and A2 oriented horizontally. A plurality of heat transfer tubes 3 are connected to the distributors 1A and 2A to circulate the refrigerant between them.

[0017] Each heat transfer tube 3 is formed in a tubular shape to allow the refrigerant to flow through it. The heat transfer tubes 3 extend in the vertical direction. Furthermore, the upper and lower ends of the heat transfer tubes 3 are inserted into insertion holes (not shown) in the cylindrical walls of the distributors 1A and 2A. Furthermore, the upper and lower ends are joined to the distributors 1A and 2A with brazing material. In this way, the heat transfer tubes 3 are connected to the distributors 1A and 2A. As a result, the refrigerant flows through the heat transfer tubes 3 when it flows through the distributors 1A and 2A.

[0018] Each heat transfer tube 3 is made of a metal with high thermal conductivity, such as pure aluminum or an aluminum alloy, to facilitate the transfer of heat from the refrigerant flowing therethrough. Furthermore, the heat transfer tubes 3 are formed with a flattened cross section to facilitate the transfer of heat from the refrigerant. That is, the heat transfer tubes 3 are flattened tubes. As shown in FIG. 1 , the heat transfer tubes 3 are arranged at a constant pitch along the tube axes A1 and A2 of the distributors 1A and 2A. This also provides gaps between the heat transfer tubes 3. Fins 4 are provided in the gaps to release the heat transferred to the heat transfer tubes 3 into the surrounding air.

[0019] The fins 4 are made of a metal with high thermal conductivity, for example, the same metal material as the heat transfer tubes 3, to facilitate heat transfer from the heat transfer tubes 3. Furthermore, the fins 4 are formed in a plate shape (not shown) to facilitate heat release into the surrounding air. The plate is folded into a corrugated shape. The fins 4 are sandwiched between adjacent heat transfer tubes 3 with the peaks and valleys of the corrugation facing the flat surfaces of the heat transfer tubes 3. The peaks and valleys of the corrugation of the fins 4 are then joined to the heat transfer tubes 3 with brazing material. Thus, the fins 4 are attached to the heat transfer tubes 3. As a result, the fins 4 release the heat transferred from the heat transfer tubes 3 into the air from the surface of the corrugated plate.

[0020] Of the distributors 1A and 2A included in the heat exchanger 100, distributor 1A employs a double-pipe structure including an inner pipe having a plurality of orifices for allowing the refrigerant to flow out and an outer pipe that houses the inner pipe, in order to distribute the refrigerant more uniformly. Next, the configuration of distributor 1A will be described in detail with reference to Figures 2 to 4.

[0021] Fig. 2 is an enlarged front view of a portion of the distributor 1A. Fig. 3 is a cross-sectional view taken along the III-III cutting line shown in Fig. 2. Fig. 4 is a cross-sectional view taken along the IV-IV cutting line shown in Fig. 2. Note that in Fig. 2, the heat transfer tubes 3 connected to the distributor 1A are omitted for ease of understanding.

[0022] As shown in FIGS. 2 to 4, the distributor 1A has an inner pipe 10A and an outer pipe 20A that houses the inner pipe 10A.

[0023] As shown in Figures 3 and 4, the inner pipe 10A is cylindrical to allow the refrigerant to flow through it. Although not shown, one end of the cylinder is connected to the refrigerant inlet of the distributor 1A, and the refrigerant is supplied into the pipe. To distribute the refrigerant, the inner pipe 10A has a plurality of orifices 11 formed in its cylindrical surface, as shown in Figures 3 and 4. The cylindrical axis of the inner pipe 10A is oriented along the pipe axis A1 described with reference to Figure 1. Although not shown, the orifices 11 are arranged at equal intervals along the pipe axis A1. As a result, the orifices 11 discharge the refrigerant evenly in the direction of the pipe axis A1, thereby distributing the refrigerant evenly.

[0024] Furthermore, the inner pipe 10A is made of a material with a higher melting point than the brazing material to prevent the orifice 11 from being blocked during the brazing process in the manufacture of the heat exchanger 100. For example, the inner pipe 10A is made of an Al-Mn aluminum alloy, specifically, an A3003 alloy. This prevents the inner pipe 10A from melting when heated during the brazing process, thereby preventing the orifice 11 from being blocked by the molten material. The inner pipe 10A is housed in the outer pipe 20A.

[0025] The outer tube 20A is formed by combining two members to accommodate the inner tube 10A therein. That is, as shown in Figures 2 to 4, the outer tube 20A is formed by combining a main body portion 21A and a cover portion 22A.

[0026] As shown in FIGS. 3 and 4 , the main body 21A is formed in the shape of a trough extending in the direction of the pipe axis A1, i.e., a U-shaped cross section. The inner diameter R1 of the main body 21A in the front-to-rear direction, i.e., the Y direction, of the U-shaped cross section is larger than the outer diameter R2 of the inner pipe 10A. The main body 21A accommodates the inner pipe 10A by inserting it through the opening of the U-shaped cross section. The inner pipe 10A is located at the center of the internal space of the U-shaped cross section. In other words, the cylindrical axis of the inner pipe 10A is coaxial with the pipe axis A1. As a result, the inner circumferential surface of the main body 21A surrounds the outer circumferential surface of the inner pipe 10A, providing a space between the inner circumferential surface of the main body 21A and the outer circumferential surface of the inner pipe 10A. As a result, the inner circumferential surface of the main body 21A does not block the opening of the orifice 11, allowing the refrigerant to flow from the orifice 11 into the internal space of the main body 21A. Furthermore, when the refrigerant flows out from the orifice 11, the main body 21A spreads the refrigerant throughout the entire pipe.

[0027] 3 and 4, the main body 21A has the same number of through holes formed therein as the heat transfer tubes 3, each having the same shape as the cross-sectional shape of the heat transfer tubes 3. The heat transfer tubes 3 are connected to the main body 21A by inserting the ends of the heat transfer tubes 3 into the through holes and joining them with brazing material. As a result, when the refrigerant flows through the main body 21A, the refrigerant is distributed to the heat transfer tubes 3.

[0028] On the other hand, the cover portion 22A is formed in an inverted U-shape in cross section that is smaller than the main body portion 21A. The width of the cover portion 22A in the Y direction is larger than the Y direction width W1 of the opening of the U-shape in cross section of the main body portion 21A, to the extent that it can be lightly press-fitted. The cover portion 22A is fitted into the opening of the main body portion 21A with the side of the opening of the inverted U-shape in cross section facing the side of the opening of the main body portion 21A, that is, with the -Z surface side of the cover portion 22A facing the +Z surface side of the main body portion 21A. More specifically, the cover portion 22A is lightly press-fitted. As a result, the cover portion 22A closes the opening of the main body portion 21A.

[0029] The main body 21A is provided with dowels 211 that protrude inward from the inner circumferential surface. Specifically, the dowels 211 are provided on each of the two opposing sidewalls of the main body 21A. The dowels 211 are provided at positions a fixed distance from the +Z end of each of the two sidewalls. As a result, the dowels 211 are provided a fixed distance inward from the open end of the main body 21A. Furthermore, each dowel 211 is formed using the half-pierce method, resulting in a shape in which the sidewalls of the main body 21A locally protrude inward. The cover 22A is lightly press-fitted into the opening of the main body 21A, and the -Z end of the cover 22A abuts against the dowels 211, thereby determining its position at a fixed position relative to the open end of the main body 21A.

[0030] 2, a plurality of dowels 211 are formed at a constant pitch in the direction of the tube axis A1 over the entire body portion 21A. The -Z end of the cover portion 22A abuts against each of the dowels 211, thereby determining the position of the cover portion 22A over the entire body portion 21A, and as a result, the opening of the body portion 21A is completely closed.

[0031] Furthermore, as shown in Figures 2 and 4, the main body 21A is provided with a plurality of claws 212 on the +Z side that are bent along the outer peripheral surface of the cover 22A. Specifically, as shown in Figure 4, the claws 212 extend from the +Z end of the opening of the main body 21A toward the +Z side and toward the inside of the opening. As a result, the claws 212 extend along the +Z side surface of the cover 22A. The claws 212 hold the cover 22A by extending along the +Z side surface of the cover 22A. As a result, the claws 212 firmly secure the cover 22A to the main body 21A.

[0032] 2, a plurality of claws 212 are formed over the entire body 21A at a constant pitch in the direction of the tube axis A1, so that the cover 22A is firmly fixed to the body 21A over the entire body.

[0033] The main body 21A and the cover 22A are formed by molding a plate of clad material covered with a brazing material.

[0034] Specifically, as shown in FIGS. 3 and 4 , the main body 21A is formed of a clad plate having a plate-shaped core material 213 and a coating layer 214 covering one side of the core material 213. The core material 213 is formed of a material with a higher melting point than the brazing material, for example, an Al-Mn-based aluminum alloy, specifically, an A3003 alloy. The coating layer 214 is formed of a brazing material, for example, an Al-Si-based aluminum alloy, specifically, an A4343 alloy. The main body 21A is formed by bending the coating layer 214 outward and the core material 213 inward. As a result, the inner peripheral surface of the main body 21A, which has a U-shaped cross section, is formed of the core material 213. As a result, the inner peripheral surface of the main body 21A does not melt during the brazing process, and if it comes into contact with the outer peripheral surface of the inner tube 10A, molten material will not adhere to the outer peripheral surface of the inner tube 10A. This prevents the orifice 11 from being blocked.

[0035] Furthermore, like the main body portion 21A, the cover portion 22A is also formed of a clad plate having a plate-shaped core material 223 and a coating layer 224 covering one side of the core material 223. The materials and bending directions of the core material 223 and the coating layer 224 are the same as those of the core material 213 and the coating layer 214 of the main body portion 21A. The cover portion 22A is lightly press-fitted into the U-shaped cross-sectional opening of the main body portion 21A with the coating layer 224 facing outward. As a result, both ends of the inverted U-shaped cross-section of the coating layer 224 of the cover portion 22A contact the inner circumferential surface of the main body portion 21A. Furthermore, the portion of the coating layer 224 connecting both ends of the inverted U-shaped cross-section contacts the inner circumferential surface of the claw portion 212. The cover portion 22A is joined to the main body portion 21A by melting the contacting portions of the coating layer 224 during a brazing process.

[0036] The cover portion 22A is joined to the main body portion 21A in the above-described orientation, and as a result, the core material 223 forms the inner peripheral surface portion of the cover portion 22A. As a result, the inner peripheral surface portion of the cover portion 22A is not melted during the brazing process, and if the outer peripheral surface portion of the inner tube 10A comes into contact with the inner peripheral surface portion, the orifice 11 is prevented from being blocked by molten material.

[0037] In this way, in the distributor 1A, the main body 21A and the cover 22A of the outer pipe 20A have inner circumferential surface portions formed of a material with a melting point higher than that of the brazing material, so that the inner circumferential surface portions do not melt during the brazing process. As a result, in the distributor 1A, even if the outer circumferential surface portion of the inner pipe 10A comes into contact with the main body 21A and the cover 22A, the orifice 11 is prevented from being blocked by the molten material adhering to the outer circumferential surface portion of the inner pipe 10A.

[0038] Next, a method for manufacturing such a distributor 1A will be described with reference to Figures 5 to 7. In the following description, the method for manufacturing the distributor 1A will be described by explaining the method for manufacturing the heat exchanger 100.

[0039] Fig. 5 is a flowchart of a method for manufacturing the heat exchanger 100. Fig. 6 is a cross-sectional view of the main body 21A of the outer pipe 20A when the heat transfer tubes 3, the fins 4, and the inner pipe 10A are assembled in the method for manufacturing the heat exchanger 100. Fig. 7 is a cross-sectional view of the main body 21A of the outer pipe 20A when the cover part 22A is lightly press-fitted.

[0040] In the manufacturing method of the heat exchanger 100, first, the heat transfer tube 3, fins 4, and the main body 21A and cover 22A of the inner tube 10A and outer tube 20A, each having the above-described shape, are fabricated (step S1). For example, the heat transfer tube 3 is fabricated by extruding a metal material of the above-described material. In fabricating the heat transfer tube 3, the outer peripheral surface of the heat transfer tube 3 may be coated with a brazing material to facilitate joining the heat transfer tube 3 to the outer tube 20A, although this is not necessarily desirable compared to leaving the opening of the orifice 11 intact without contacting the molten brazing material with the inner tube 10A. Furthermore, the fins 4, the main body 21A and cover 22A of the inner tube 10A and outer tube 20A, each having the above-described shape, are fabricated by pressing a metal plate of the above-described material.

[0041] Next, the heat transfer tube 3, fins 4, and inner tube 10A are attached to the main body 21A of the outer tube 20A (step S2). For example, the fins 4 are attached to the heat transfer tube 3, and the end of the heat transfer tube 3 in this state is inserted into the through-hole 215 formed in the main body 21A, as shown in Fig. 6. At this time, since a long heat transfer tube 3 is attached to the main body 21A, it is desirable to attach the heat transfer tube 3 to the main body 21A with the opening of the U-shaped cross section of the main body 21A facing horizontally and with the axis of the heat transfer tube 3 facing horizontally.

[0042] 6, the inner pipe 10A is inserted into the internal space of the main body 21A. For example, an end cap (not shown) is used to position the inner pipe 10A coaxially with the main body 21A. The orifice 11 is oriented toward, for example, the sidewalls of the main body 21A that face each other in the vertical direction of the U-shaped cross section.

[0043] Returning to FIG. 5 , the cover portion 22A is then lightly press-fitted into the main body portion 21A of the outer tube 20A (step S3). As shown in FIG. 7 , the width W2 of the cover portion 22A is larger than the width W1 of the U-shaped cross-sectional opening of the main body portion 21A to the extent that light press-fitting is possible. The cover portion 22A is then pressed into the main body portion 21A with the inverted U-shaped cross-sectional surface of the cover portion 22A facing inward into the U-shaped cross-sectional opening of the main body portion 21A. To accurately assemble the cover portion 22A, it is recommended to press the cover portion 22A until the end of the cover portion 22A abuts the dowel 211 of the main body portion 21A. This allows the cover portion 22A to be lightly press-fitted into the main body portion 21A.

[0044] Next, although not shown, the claws 212 provided on the main body 21A are bent so that the claws 212 are aligned with the outer peripheral surface of the cover 22A. This causes the claws 212 to crimp the cover 22A. As a result, the claws 212 hold the cover 22A.

[0045] Next, as shown in FIG. 5 , brazing is performed (step S4). Specifically, the main body portion 21A, into which the cover portion 22A was lightly press-fitted in step S3, is heated to melt the brazing material. At this time, because the cylindrical axis of the inner pipe 10A is oriented horizontally as shown in FIGS. 6 and 7 , gravity may cause the inner pipe 10A to bend and come into contact with the inner circumferential surface of the main body portion 21A. However, the inner circumferential surfaces of the main body portion 21A and the cover portion 22A of the outer pipe 20A are formed by core materials 213 and 223, which do not melt at the temperature at which the brazing material melts. Because the inner pipe 10A is surrounded by these inner circumferential surfaces, molten material will not adhere to the inner circumferential surface even if the inner pipe 10A bends and comes into contact with these inner circumferential surfaces. As a result, the orifice 11 formed in the inner pipe 10A is prevented from being blocked by the brazing material.

[0046] The main body portion 21A is heated until the temperature reaches a melting point of the brazing material of the coating layers 214, 224. Alternatively, if the outer circumferential surface of the heat transfer tube 3 is coated with brazing material, the heating is continued until the temperature reaches a melting point of the brazing material of the heat transfer tube 3 in addition to the brazing material of the coating layers 214, 224. After heating to the melting point of the brazing material, the molten brazing material is solidified by cooling. This completes the brazing in step S4. As a result, the heat transfer tube 3 is joined to the main body portion 21A by the brazing material of the coating layer 214 of the main body portion 21A of the outer tube 20A. Alternatively, if the outer circumferential surface of the heat transfer tube 3 is coated with brazing material, the heat transfer tube 3 is joined to the main body portion 21A by the brazing material of the heat transfer tube 3. Furthermore, the cover portion 22A is joined to the main body portion 21A by the brazing material of the coating layer 224 of the cover portion 22A of the outer tube 20A.

[0047] Through the above steps, the distributor 1A is completed. In parallel with steps S2-S4, the heat transfer tubes 3 and fins 4 are also assembled and brazed for the distributor 2A, thereby completing the heat exchanger 100 to which the distributor 2A is attached in addition to the distributor 1A. This completes the manufacturing method for the heat exchanger 100.

[0048] In step S3, the cover portion 22A is lightly press-fitted into the main body portion 21A of the outer tube 20A. However, in the first embodiment, it is sufficient that the cover portion 22A is fitted into the main body portion 21A of the outer tube 20A. Therefore, the cover portion 22A may be fitted into the main body portion 21A of the outer tube 20A by an interference fit, for example, by press fitting or strong press fitting. The cover portion 22A may also be fitted into the main body portion 21A of the outer tube 20A by an intermediate fit, for example, by driving in. This is because these methods can also join the cover portion 22A and the main body portion 21A with sufficient joining strength.

[0049] Furthermore, the main body 21A of the outer pipe 20A described above is an example of a first member as defined in the present disclosure. Furthermore, the cover portion 22A of the outer pipe 20A is an example of a second member as defined in the present disclosure. The cylindrical portion of the outer pipe 20A, which is elliptical in cross section and formed by combining the main body 21A, which is U-shaped in cross section, and the cover portion 22A, which is inverted U-shaped in cross section, is an example of a cylindrical portion as defined in the present disclosure. Furthermore, the inner circumferential surface portion of the outer pipe 20A is an example of a portion facing an orifice as defined in the present disclosure. Furthermore, the dowel 211 is an example of a protrusion as defined in the present disclosure. The heat transfer tube 3 is an example of a refrigerant tube through which a refrigerant is distributed as defined in the present disclosure.

[0050] Furthermore, steps S2 and S3 are an example of a process for assembling an outer tube having a cylindrical portion as defined in the present disclosure, placing an inner tube in the internal space of the cylindrical portion, and aligning an orifice with a portion of the inner surface.

[0051] As described above, in the distributor 1A according to the first embodiment, the inner peripheral surface portion of the outer pipe 20A is configured with the core materials 213, 223 formed of a material having a higher melting point than the brazing material. This inner peripheral surface portion faces the orifice 11 of the inner pipe 10A. Therefore, the inner peripheral surface portion of the outer pipe 20A does not melt during brazing and function as the brazing material. As a result, even if the inner pipe 10A bends and the orifice 11 comes into contact with the inner peripheral surface portion of the outer pipe 20A, the orifice 11 is prevented from being blocked by the brazing material.

[0052] The outer tube 20A is assembled by lightly press-fitting the cover portion 22A into the main body portion 21A, so the main body portion 21A and the cover portion 22A can be firmly joined with a small amount of brazing material. As a result, when brazing the main body portion 21A and the cover portion 22A, the brazing material is prevented from flowing out to the inner peripheral surface of the outer tube 20A. As a result, the orifice 11 is less likely to be blocked by the brazing material.

[0053] (Embodiment 2) In the distributor 1A according to embodiment 1, the main body 21A and cover 22A of the outer pipe 20A have coating layers 214, 224 formed of brazing material. However, the outer pipe 20A is not limited to this. The outer pipe 20A has an inner diameter larger than the outer diameter of the inner pipe 10A, and the inner pipe 10A is accommodated in the internal space formed by the inner circumferential surface portion so that the inner circumferential surface portion surrounds the outer circumferential surface portion of the inner pipe 10A. The inner circumferential surface portion of the outer pipe 20A is formed of a material with a higher melting point than the brazing material, and has a portion facing the orifice 11. Therefore, only the cover portion 22A of the outer pipe 20A may have the coating layer 224.

[0054] In the distributor 1B according to the second embodiment, only the cover portion 22B has a coating layer 224. The configuration of the distributor 1B will be described below with reference to Fig. 8. The configuration of the second embodiment that differs from that of the first embodiment will be mainly described.

[0055] 8 is a cross-sectional view of a distributor 1B according to embodiment 2. Note that Fig. 8 shows a cross section taken along the same line as the III-III line shown in Fig. 2.

[0056] As shown in FIG. 8 , in the distributor 1B, the main body 21B provided on the outer tube 20B is formed only with a core material 213, without the coating layer 214 described in the first embodiment. On the other hand, the cover 22B has a coating layer 224 in addition to the core material 223, as in the first embodiment. The coating layer 224 is disposed facing the outside of the outer tube 20B. As a result, the end of the coating layer 224 of the cover 22B, which is inverted U-shaped in cross section, abuts against the core material 213 of the main body 21B. The cover 22B is joined to the core material 213 of the main body 21B by a brazing material portion formed by melting the end of the coating layer 224. This allows the cover 22B to be integrated with the main body 21B.

[0057] On the other hand, as a result of having the above-described configuration, the inner peripheral surface portion of the outer tube 20B is formed of the core materials 213 and 223. As a result, the inner peripheral surface portion of the outer tube 20B is formed of a material with a higher melting point than the brazing material and does not melt during the brazing process. As a result, even if the inner tube 10B comes into contact with the inner peripheral surface portion of the outer tube 20B during the brazing process in manufacturing the distributor 1B, the orifice 11 is prevented from being blocked by the brazing material.

[0058] As described above, in the distributor 1B according to the second embodiment, of the main body 21B and the cover 22B of the outer tube 20B, only the cover 22B has a coating layer 224 formed of a brazing material. The coating layer 224 faces the outer peripheral surface of the outer tube 20B. As a result, the inner peripheral surface of the outer tube 20B is formed of core materials 213 and 223 made of a material with a higher melting point than the brazing material. Therefore, the inner peripheral surface of the outer tube 20B does not melt during the brazing process when manufacturing the distributor 1B. Even if the inner tube 10B comes into contact with the inner peripheral surface of the outer tube 20B, the orifice 11 will not be blocked by the molten material.

[0059] As described above, in the present disclosure, the inner circumferential surface portions of the outer tubes 20A, 20B may be formed of a material having a higher melting point than the brazing material and may have a portion facing the orifice 11. Therefore, the cover portions 22A, 22B may not have the coating layer 224 and may be formed of only the core material 223.

[0060] Fig. 9 is a cross-sectional view of a modified example of distributor 1B. Fig. 10 is a cross-sectional view of another modified example of distributor 1B. As with Fig. 8, Figs. 9 and 10 also show cross sections taken along the same line as the III-III line shown in Fig. 2.

[0061] As shown in FIG. 9, the cover portion 22B may be formed only by a core material 223 and joined to the main body portion 21B by a brazing material portion 225.

[0062] Here, the brazing material portion 225 is a portion formed by the penetration of molten brazing material into the gap between the cover portion 22B and the main body portion 21B during the brazing process during the manufacture of the distributor 1B, and is a portion formed by, for example, a pre-placed brazing material or a paste brazing material. In the distributor 1B, the cover portion 22B is lightly press-fitted into the main body portion 21B, so that the molten brazing material can penetrate between the cover portion 22B and the main body portion 21B. The brazing material portion 225 is formed by the penetration of the molten brazing material between the cover portion 22B and the main body portion 21B.

[0063] 9, the inner peripheral surface of the outer tube 20B is also formed of a material with a higher melting point than the brazing material, so that even if the inner tube 10B comes into contact with the inner peripheral surface of the outer tube 20B during the brazing process, the orifice 11 will not be blocked by the molten material.

[0064] Although not shown in FIG. 9 , the main body portion 21B of the outer tube 20B and the heat transfer tube 3 may be joined by, for example, using a pre-placed brazing material or a paste brazing material in a brazing process, allowing molten brazing material to penetrate between the main body portion 21B and the heat transfer tube 3.

[0065] 10, the cover portion 22B may be formed only from a core material 223 and attached to the main body portion 21B by fitting into a U-shaped opening in cross section of the main body portion 21B. The cover portion 22B may be joined to the main body portion 21B by fitting, rather than by brazing material. In this case, the fitting is preferably a light press fit, which facilitates assembly and ensures sufficient bonding strength. Alternatively, the fitting may be a press fit or a strong press fit. Even in this configuration, the inner circumferential surface of the outer tube 20B can be formed from a material with a higher melting point than the brazing material, thereby preventing the orifice 11 from being blocked.

[0066] (Embodiment 3) In the distributors 1A and 1B according to Embodiments 1 and 2, the ends of the U-shaped cross section of the main body portions 21A and 21B of the outer tubes 20A and 20B are linear in cross section. Similarly, the ends of the inverted U-shaped cross section of the cover portions 22A and 22B of the outer tubes 20A and 20B are also linear in cross section. However, the shapes of the main body portions 21A and 21B and the cover portions 22A and 22B are not limited to this. The main body portions 21A and 21B only need to form a portion of a cylindrical portion whose inner diameter is larger than the outer diameter of the inner tube 10A. The cover portions 22A and 22B only need to form the remaining portion of the cylindrical portion and be joined to the main body portions 21A and 21B with brazing material. The shapes of the main body portions 21A and 21B and the cover portions 22A and 22B of the outer tube 20B are arbitrary as long as they satisfy this condition.

[0067] In a distributor 1C according to the third embodiment, a main body 21C of an outer tube 20C has an inclined surface at an open end of a U-shaped cross section to facilitate fitting of a cover 22C. The configuration of the distributor 1C will be described below with reference to Fig. 11. The configuration of the third embodiment that differs from the first and second embodiments will be mainly described.

[0068] 11 is a cross-sectional view of a distributor 1C according to embodiment 3. Note that Fig. 11 shows a cross section taken along the same line as the III-III line shown in Fig. 2.

[0069] As shown in FIG. 11 , of the main body 21C and cover 22C included in the outer tube 20C, a chamfered portion 216 or 217 is formed at each corner formed by the end face and inner peripheral surface of each of the two opposing side wall portions of the U-shaped cross section of the main body 21C.

[0070] The chamfered portions 216, 217 have surfaces that slope outward toward the end faces of the sidewall portions of the U-shaped cross section of the main body portion 21C. That is, the chamfered portion 216 has a surface that slopes toward the +Y side toward the +Z end of the sidewall portion. The chamfered portion 217 has a surface that slopes toward the -Y side toward the +Z end of the sidewall portion. As a result, the chamfered portions 216, 217 can guide the end of the inverted U-shaped cross section of the cover portion 22C into the opening of the U-shaped cross section of the main body portion 21C when lightly press-fitting the cover portion 22C into the main body portion 21C of the outer tube 20C in step S3 of the manufacturing method of the heat exchanger 100. This makes it easy to press-fit the cover portion 22C into the main body portion 21C.

[0071] In distributor 1C, as in the first and second embodiments, the inner peripheral surface of main body 21C of outer tube 20C is formed of a material with a higher melting point than the brazing filler metal. Therefore, even if outer tube 20C comes into contact with the outer peripheral surface of inner tube 10C, the molten brazing filler metal is less likely to adhere to the outer peripheral surface of inner tube 10C. As a result, even in distributor 1C, the orifice of inner tube 10C is less likely to become clogged.

[0072] Furthermore, in the distributor 1C, the dowel 211 is formed on the main body 21C of the outer tube 20C, but the presence or absence of the dowel 211 is optional. Therefore, in the distributor 1C, the dowel 211 may be omitted.

[0073] As described above, in the distributor 1C according to the third embodiment, the chamfered portions 216, 217 are provided at the corners formed by the opening periphery and the inner peripheral surface of the main body 21C of the outer tube 20C. This makes it easy to lightly press-fit the cover 22C into the main body 21C during manufacturing.

[0074] (Variant) In the distributor 1C of embodiment 3, chamfered portions 216, 217 are provided on the inner surface side of the opening end portion of the main body portion 21C of the outer tube 20C, but the configuration that makes it easier to lightly press-fit the cover portion 22C is not limited to this.

[0075] Fig. 12 is a cross-sectional view of a modified example of distributor 1C according to embodiment 3. Fig. 13 is a cross-sectional view of another modified example of distributor 1C. Fig. 14 is a cross-sectional view of yet another modified example of distributor 1C. Note that Figs. 12 to 14 show cross sections taken along a cutting line that cuts the same portion as the III-III cutting line shown in Fig. 2.

[0076] 12, in the distributor 1C, the cover portion 22C of the outer tube 20C may have chamfered portions 226, 227. In this case, the chamfered portions 226, 227 may be provided on the outer peripheral surface of each end of two opposing side wall portions of the inverted U-shape of the cover portion 22C. This is because such a configuration makes it easier to lightly press-fit the cover portion 22C into the main body portion 21C during manufacturing.

[0077] 13, in the distributor 1C, the two opposing sidewalls of the U-shaped cross section of the main body 21C of the outer tube 20C may be bent outward at the open end. In other words, the width of the open end of the U-shaped cross section of the main body 21C may increase as the open end approaches the open end. This configuration also makes it easier to lightly press-fit the cover 22C into the main body 21C during manufacturing.

[0078] 14, in the distributor 1C, the main body 21C of the outer pipe 20C is elastically or plastically deformable, and the width W1 of the U-shaped cross-sectional opening of the main body 21C of the outer pipe 20C may be smaller than the width W3 of the internal space at the back of the opening. When the cover 22C is lightly press-fitted into the U-shaped cross-sectional opening of the main body 21C during the manufacture of the distributor 1C, the force applied by the light press-fitting may elastically or plastically deform the main body 21C, expanding the width W1 of the opening to a size that allows the cover 22C to be inserted.

[0079] In Figure 14, when the cover portion 22C is lightly pressed into the main body portion 21C, the width W1 is smaller than the width W3, but when the cover portion 22C is not lightly pressed into the main body portion 21C, the width W1 may be smaller than the width W3, and when the cover portion 22C is lightly pressed into the main body portion 21C, the width W1 may be greater than or equal to the width W3.

[0080] The distributor 1A-1C, the heat exchanger 100, the manufacturing method of the distributor 1A-1C, and the manufacturing method of the heat exchanger 100 according to the embodiments of the present disclosure have been described above, but the manufacturing methods of the distributor 1A-1C, the heat exchanger 100, the distributor 1A-1C, and the manufacturing method of the heat exchanger 100 are not limited to this.

[0081] For example, in embodiments 1-3, the inner tubes 10A-10C are cylindrical. However, the inner tubes 10A-10C are not limited to this. In the present disclosure, (a) the inner tubes 10A-10C may have an orifice 11 on their outer circumferential surface, and the refrigerant may flow out from the orifice 11. Therefore, the specific shape of the inner tubes 10A-10C is arbitrary as long as it satisfies condition (a). For example, the inner tubes 10A-10C may be a square tube with rounded corners or a square tube with right-angled corners.

[0082] Furthermore, in embodiments 1-3, the orifice 11 orifice hole is oriented toward the sidewall portion of the U-shaped cross section of the main body portions 21A-21C of the outer tubes 20A-20C. In other words, it is oriented in the Y direction. However, the orientation of the orifice 11 orifice hole is not limited to this. In the present disclosure, (b) the orifice 11 only needs to be provided on the outer peripheral surface portion of the inner tubes 10A-10C. Therefore, the orientation of the orifice 11 orifice hole is arbitrary as long as it satisfies the condition (b). The orifice 11 may be oriented toward the cover portions 22A-22C of the outer tubes 20A-20C, for example.

[0083] Furthermore, in embodiments 1-3, the outer tubes 20A-20C have a rectangular cylindrical shape with rounded corners, in other words, an oval shape in cross section. However, the outer tubes 20A-20C are not limited to this. In the present disclosure, (c) the outer tubes 20A-20C only need to have an inner diameter larger than the outer diameter of the inner tubes 10A-10C, and accommodate the inner tubes 10A-10C in an internal space formed by the inner circumferential surface portion, with the inner circumferential surface portion surrounding the outer circumferential surface portion of the inner tubes 10A-10C. Note that the outer tubes 20A-20C may accommodate the entire inner tubes 10A-10C, or may accommodate only a portion of the inner tubes 10A-10C.

[0084] Alternatively, (d) the outer tubes 20A-20C may have a first member forming a part of the cylindrical portion whose inner diameter is larger than the outer diameter of the inner tubes 10A-10C, and a second member forming the remaining part of the cylindrical portion and joined to the first member with brazing material, and the inner tubes 10A-10C may be accommodated in an internal space formed by the inner peripheral surface of the cylindrical portion such that the inner peripheral surface surrounds the outer peripheral surface of the inner tubes 10A-10C. Here, the first member may be, for example, the main body portions 21A-21C described in Embodiments 1-3. The second member may be, for example, the cover portions 22A-22C described in Embodiments 1-3.

[0085] Therefore, the specific shape of the outer tubes 20A-20C is arbitrary as long as it satisfies the above condition (d). For example, the outer tubes 20A-20C may be cylindrical, i.e., circular tubes, or may be angular, i.e., rectangular tubes, for example.

[0086] In embodiments 1-3, multiple dowels 211 are formed at a constant pitch in the direction of the tube axis A1 over the entire body portion 21A of the outer tubes 20A-20C. However, the outer tubes 20A-20C are not limited to this. The outer tubes 20A-20C may be any tube as long as they satisfy the above-mentioned conditions (c) and (d). Therefore, the presence or absence of the dowels 211 is optional. Furthermore, if the distributors 1A-1C are provided with dowels 211, the shape of the dowels is also optional.

[0087] FIG. 15 is an enlarged front view of a first modified example of the dowel 211 provided in the distributor 1A according to the first embodiment.

[0088] As shown in Figure 15, the dowel 211 may extend in the direction of the tube axis A1, thereby extending across the entire body portion 21A of the outer tube 20A. In this case, although not shown, it is preferable that only one dowel 211 is formed on each of two opposing sidewall portions of the U-shaped cross section of the body portion 21A of the outer tube 20A. In this configuration, when the coating layer 224 of the cover portion 22A melts during the brazing process in manufacturing the distributor 1A, the dowel 211 prevents the molten brazing material from flowing into the internal space of the outer tube 20A through the gap between the cover portion 22A and the body portion 21A. As a result, the orifice 11 is prevented from being blocked.

[0089] Furthermore, although it has been stated above that the presence or absence of the dowels 211 is optional for the outer tubes 20A-20C in accordance with the conditions (c) and (d) above, the outer tubes 20A-20C do not necessarily have to have the dowels 211.

[0090] Fig. 16 is a cross-sectional view of a modified example of the outer tube 20A included in the distributor 1A according to embodiment 1. Note that Fig. 16 shows a cross section taken along a cutting line that cuts the same portion as the III-III cutting line shown in Fig. 2.

[0091] As shown in FIG. 16 , the outer tube 20A may have a main body 21A whose inner circumferential surface does not include protrusions, including dowels 211. In this case, as shown in FIG. 16 , the main body 21A may have a U-shaped cross section, with steps 218 formed on the inner surfaces of two opposing sidewalls of the U-shaped cross section, and the distance between the two sidewalls may be greater on the opening side than the steps 218. As a result, the Y-direction width W4 may be greater than the inner diameter R3 of the bottom of the U-shaped cross section by a certain depth from the opening. Furthermore, the Y-direction width of the cover 22A may be greater than the width W4 to a degree that allows light press-fitting, but greater than the inner diameter R3 to a degree that prevents light press-fitting. This shape of the main body 21A prevents the cover 22A from being lightly press-fitted into the main body 21A beyond a certain depth from the opening of the main body 21A, thereby allowing the cover 22A to be pressed into a certain length. In other words, if the main body portion 21A has this shape, the end of the inverted U-shaped cross section of the cover portion 22A can be abutted against the step 218 on the inner surface of the main body portion 21A, and the position of the cover portion 22A can be determined by the step 218.

[0092] In the embodiments 1-3, the brazing process in the manufacturing method of the heat exchanger 100 and distributors 1A-1C is performed by simply heating the main body portion 21A into which the cover portion 22A is lightly press-fitted. However, the brazing process is not limited to this. In the brazing process, at least one brazing jig that maintains the positional relationship between the main body portion 21A and the cover portion 22A may be used. In other words, the cover portion 22A may be fixed to the main body portion 21A with at least one brazing jig, and the brazing material may be melted by heating.

[0093] Fig. 17 is a cross-sectional view of a brazing jig 30 used in a brazing step provided in a modified example of the manufacturing method of the distributor 1A according to embodiment 1, and the main body 21A and cover 22A fixed by the brazing jig 30. Fig. 18 is an enlarged front view showing an example of an attachment position of the brazing jig 30 used in the brazing step. Fig. 19 is an enlarged front view showing another example of an attachment position of the brazing jig 30 used in the brazing step.

[0094] In the brazing process, a brazing jig 30 having an inverted U-shaped cross section, as shown in FIG. 17 , may be used. The main body 21A and cover 22A to be brazed are in a state in which the cover 22A, which has an inverted U-shaped cross section, is lightly press-fit into the opening of the U-shaped main body 21A, which has a U-shaped cross section. The brazing jig 30 may be placed over the main body 21A and cover 22A in this state and tighten the side walls of the U-shape of the main body 21A. As shown in FIG. 17 , tightening the brazing jig 30 compresses the main body 21A and cover 22A by a compression amount P on each of the +Y side and the −Y side, and the sum of these compression amounts, 2P, may correspond to the amount of light press-fit. This is because, if the brazing jig 30 is fastened in this manner, even if the cover portion 22A is not lightly press-fitted into the main body portion 21A, the brazing jig 30 fastens the side wall of the main body portion 21A, thereby making it possible to lightly press-fit the cover portion 22A into the main body portion 21A. The brazing jig 30 is preferably fastened at a brazing temperature, for example, 600°C.

[0095] The brazing jig 30 is preferably made of a material with a smaller linear expansion coefficient than the material of the main body 21A and the cover 22A. For example, if the main body 21A and the cover 22A are made of aluminum, the brazing jig 30 is preferably made of stainless steel or carbon. If the brazing jig 30 is made of stainless steel, a lubricant is preferably applied to the brazing jig 30. For example, carbon is preferably sprayed onto the brazing jig 30 using a carbon spray.

[0096] Alternatively, a specific surface shape may be formed on the surface of the brazing jig 30, resulting in a specific surface roughness. In this case, the brazing jig 30 may be able to transfer the specific surface shape by plastically deforming the side wall of the fastened main body 21A. This is because such a brazing jig 30 can process the side wall of the main body 21A to have the above-mentioned surface roughness. For example, the above-mentioned surface roughness can improve the drainage properties of the main body 21A.

[0097] In the brazing process, as shown in Fig. 18, if the brazing jig 30 is formed to have a thickness in the X direction that is shorter than the main body portion 21A and the cover portion 22A, it is desirable to prepare multiple brazing jigs 30. The multiple brazing jigs 30 can be placed in positions that overlap the dowels 211 and fasten the main body portion 21A. Alternatively, as shown in Fig. 19, the multiple brazing jigs 30 can be placed between the dowels 211 and fasten the main body portion 21A without overlapping the dowels 211.

[0098] Furthermore, in embodiments 1-3, the main body portions 21A-21C of the outer pipes 20A-20C are provided with multiple claw portions 212. However, the outer pipes 20A-20C only need to satisfy the above-described conditions (c) and (d). Therefore, the presence or absence of the claw portions 212 is optional. For example, the main body portions 21A of the outer pipes 20A-20C may not be provided with the claw portions 212. In such a case, the brazing jig 30 described above may be used in the brazing process. This is because the brazing jig 30 functions similarly to the claw portions 212, which firmly join the main body portion 21A and the cover portion 22A. As a result, when the brazing jig 30 is used in the brazing process, the main body portion 21A and the cover portion 22A can be firmly joined.

[0099] Fig. 20 is an enlarged front view showing an example of a brazing jig 30 used in a brazing step included in a manufacturing method of a modified example of the distributor 1A according to embodiment 1. Fig. 21 is a front view showing another example of the brazing jig 30. Fig. 22 is a front view showing yet another example of the brazing jig 30.

[0100] As shown in FIG. 20 , the outer tube 20A does not have claws 212, but may have dowels 211. At least one of the above-described brazing jigs 30 may be used in the brazing step of the manufacturing method of the modified distributor 1A including such an outer tube 20A. When multiple brazing jigs 30 are used in the brazing step, each brazing jigs 30 may be installed in a position overlapping one dowel 211 in a front view as shown in FIG. 20 . Furthermore, as shown in FIG. 21 , each brazing jig 30 may have a width that overlaps multiple dowels 211 in a front view and be installed overlapping the multiple dowels 211. Furthermore, when one brazing jig 30 is used in the brazing step, the brazing jig 30 may cover the entire main body portion 21A and the cover portion 22A, specifically the entire X-direction, and tighten the entire X-direction of the U-shaped side wall of the main body portion 21A, as shown in FIG. 22 . Naturally, the brazing jig 30 may clamp the entire U-shaped side wall of the main body 21A in the X direction, or may clamp only a part of the U-shaped side wall in the X direction.

[0101] In the embodiments 1 to 3, the claws 212 are bent along the outer peripheral surfaces of the cover portions 22A to 22C, and as a result, are bent in an arc shape. However, as described above, the presence or absence of the claws 212 is optional, and as a result, when the main body portions 21A to 21C are provided with the claws 212, the shape of the claws 212 at that time is also optional.

[0102] In the first to third embodiments, the core materials 213 and 223 of the main body portions 21A-21C and the cover portions 22A-22C of the outer tubes 20A-20C are made of an Al-Mn-based aluminum alloy, and the coating layers 214 and 224 are made of an Al-Si-based aluminum alloy. However, these are merely examples. For the outer tubes 20A-20C, (e) the core materials 213 and 223 may be made of a material with a higher melting point than the brazing material, and the coating layers 214 and 224 may be made of the brazing material. Here, the material with a higher melting point than the brazing material that forms the core materials 213 and 223 refers to a material with a higher melting point than the brazing material that forms the coating layers 214 and 224, or a material with a higher melting point than the brazing material that forms the coating layer that covers the outer surface of the heat transfer tube 3. Therefore, the material of the core materials 213 and 223 may be any material as long as it satisfies the above condition (e).

[0103] In addition, in embodiments 1-3, distributors 1A-1C are provided on the top of heat exchanger 100, but distributors 1A-1C are not limited to this and may be any that can be applied to heat exchangers 100 in general.

[0104] In addition, in the embodiments 1-3, the heat exchanger 100 includes the heat transfer tubes 3 and the fins 4 in addition to the distributors 1A-1C, but the heat exchanger 100 is not limited to this. The heat exchanger 100 may not include the fins 4, but may include the distributors 1A-1C and the heat transfer tubes 3, i.e., the refrigerant tubes.

[0105] As described above, the distributors 1A-1C, the heat exchanger 100, the manufacturing method of the distributors 1A-1C, and the manufacturing method of the heat exchanger 100 are not limited to the above-described embodiments, and various modifications and substitutions can be made. Various embodiments of the present disclosure are described below as appendices.

[0106] (Note 1) A distributor comprising: an inner pipe having an orifice on its outer peripheral surface from which a refrigerant flows out; and an outer pipe having an inner diameter larger than the outer diameter of the inner pipe, the outer peripheral surface of the outer pipe accommodating the inner pipe in an internal space defined by the inner peripheral surface of the inner pipe, the inner peripheral surface of the outer pipe surrounding the outer peripheral surface of the inner pipe; wherein a plurality of refrigerant pipes are connected to the outer pipe, the refrigerant being joined with a brazing material and distributing the refrigerant therethrough; and a portion of the inner peripheral surface of the outer pipe facing the orifice is formed of a material having a melting point higher than that of the brazing material. (Supplementary Note 2) A distributor comprising: an inner pipe having an orifice on its outer peripheral surface portion from which a refrigerant flows out; and an outer pipe having a first member forming a part of a tubular portion having an inner diameter larger than the outer diameter of the inner pipe, and a second member forming the remaining part of the tubular portion and joined to the first member with a brazing material, the outer pipe containing the inner pipe in an internal space formed by the inner peripheral surface portion of the tubular portion with the inner peripheral surface portion surrounding the outer peripheral surface portion of the inner pipe, wherein a facing portion of the inner peripheral surface portion of the outer pipe facing the orifice is formed of a material having a higher melting point than the brazing material. (Supplementary Note 3) A distributor according to Supplementary Note 1 or 2, wherein the entire inner peripheral surface portion including the facing portion is formed of the material having a higher melting point than the brazing material. (Supplementary Note 4) The distributor according to Supplementary Note 2, wherein the first member has an opening in the part of the cylindrical portion that opens to the internal space of the cylindrical portion, and the second member is fitted into the opening, and a portion that contacts the inner wall of the opening is covered with a coating layer formed from the brazing material. (Supplementary Note 5) The distributor according to Supplementary Note 2, wherein the first member has a U-shape when viewed in a cross section perpendicular to the cylindrical axis of the cylindrical portion, and the second member has another U-shape that is smaller than the U-shape of the first member when viewed in the cross section, and is fitted inside the U-shaped opening of the first member. (Supplementary Note 6) The distributor according to Supplementary Note 5, wherein the first member has a chamfered portion at a corner formed by an end and an inner surface of the U-shape when viewed in the cross section. (Supplementary Note 7) The distributor according to Supplementary Note 5 or 6, wherein the U-shape of the first member when viewed in the cross section has a shape such that the opening becomes larger toward the open end.(Supplementary Note 8) The distributor according to any one of Supplementary Notes 5 to 7, wherein the second member has a chamfered portion at a corner formed by an end of the other U-shape and an outer surface when viewed in the cross section. (Supplementary Note 9) The distributor according to any one of Supplementary Notes 5 to 8, wherein the first member has a protrusion on each of inner surfaces of two opposing side wall portions of the U-shape when viewed in the cross section, the protrusion abutting against an end of the other U-shape of the second member when viewed in the cross section and determining the position of the end when the second member is fitted. (Supplementary Note 10) The distributor according to Supplementary Note 9, wherein the protrusion extends in a direction in which a cylindrical axis of the tubular portion extends. (Supplementary Note 11) The distributor according to any one of Supplementary Notes 5 to 8, wherein the first member has a step on each of the inner surfaces of two side wall portions facing each other in the U-shape when viewed in the cross section, and the distance between the portions of the two side wall portions on the opening side is larger than the step, and each end of another U-shape of the second member when viewed in the cross section abuts against each of the steps. (Supplementary Note 12) A heat exchanger comprising: the distributor according to any one of Supplementary Notes 1 to 11; a plurality of refrigerant pipes connected to the distributor, through which a refrigerant is distributed from the distributor and which transfer heat of the refrigerant as the refrigerant flows; and a plurality of fins attached to the plurality of refrigerant pipes. (Supplementary Note 13) A method for manufacturing a distributor, comprising the steps of assembling an outer tube comprising a cylindrical portion by combining a first member forming a part of the cylindrical portion with a second member forming the remaining part of the cylindrical portion, the second member having a brazing filler material provided in a part that will become a joining part when the first member and the second member are combined and joined, and further disposing an inner tube having an orifice in an outer peripheral surface part and an outer diameter smaller than an inner diameter of the cylindrical portion in an internal space of the cylindrical portion, and arranging the orifice opposite a part of an inner peripheral surface part formed of a material having a higher melting point than the brazing filler material and of one of the first member and the second member; and brazing the second member to the first member by heating the assembled cylindrical portion and the inner tube disposed in the internal space of the cylindrical portion at a temperature higher than the melting point of the brazing filler material to melt the brazing filler material.(Supplementary Note 14) The method for manufacturing a distributor according to Supplementary Note 13, wherein in the step of combining the first member and the tubular second member to assemble the outer pipe comprising the tubular portion, the first member and the tubular second member are combined by lightly press-fitting the second member into the first member. (Supplementary Note 15) The method for manufacturing a distributor according to Supplementary Note 14, wherein the first member has an opening in the part of the tubular portion, and the second member is fittable into the opening, and in the step of combining the first member and the tubular second member to assemble the outer pipe comprising the tubular portion, the first member and the tubular second member are combined by lightly press-fitting the second member into the opening of the first member. (Supplementary Note 16) The method for manufacturing a distributor according to any one of Supplementary Notes 13 to 15, wherein the first member has a U-shape when viewed in a cross section perpendicular to the cylindrical axis of the tubular portion, and the second member has another U-shape that is smaller than the U-shape of the first member when viewed in the cross section and can be fitted inside the U-shaped opening of the first member, and in the step of assembling the outer tube including the tubular portion by combining the first member and the tubular second member, the combination is performed by lightly press-fitting the second member into the U-shaped opening of the first member. (Supplementary Note 17) The method for manufacturing a distributor according to any one of Supplementary Notes 13 to 16, wherein the entire inner circumferential surface portion including the part is formed of the material having a higher melting point than the brazing material. (Supplementary Note 18) A method for manufacturing a distributor according to any one of Supplements 13 to 17, wherein in the step of brazing the second member to the first member, a jig that keeps the first member and the second member combined and attached is attached to the assembled cylindrical portion, and the cylindrical portion to which the jig is attached is heated to the temperature. (Supplementary Note 19) A method for manufacturing a heat exchanger, comprising the method for manufacturing a distributor according to any one of Supplements 13 to 18, and further comprising, before the step of brazing the second member to the first member, a step of assembling a plurality of refrigerant pipes, each having a plurality of fins attached, to the combined first member and second member.

[0107] The present disclosure allows various embodiments and modifications without departing from the broad spirit and scope of the present disclosure. Furthermore, the above-described embodiments are intended to explain the present disclosure and do not limit the scope of the present disclosure. That is, the scope of the present disclosure is defined by the claims, not the embodiments. Various modifications made within the scope of the claims and within the meaning of the disclosure equivalent thereto are considered to be within the scope of the present disclosure.

[0108] This application is based on Japanese Patent Application No. 2024-8348, filed on January 23, 2024. The entire specification, claims, and drawings of Japanese Patent Application No. 2024-8348 are incorporated herein by reference.

[0109] 1A-1C distributor, 2A distributor, 3 heat transfer tube, 4 fin, 5, 6 connection portion, 10A-10C inner tube, 11 orifice, 20A-20C outer tube, 21A-21C main body portion, 22A-22C cover portion, 30 brazing jig, 100 heat exchanger, 211 dowel, 212 claw portion, 213 core material, 214 coating layer, 215 through hole, 216, 217 chamfered portion, 218 step, 223 core material, 224 coating layer, 225 brazing material portion, 226, 227 chamfered portion, A1, A2 tube axis, P compression amount, R1 inner diameter, R2 outer diameter, R3 inner diameter, W1-W4 width.

Claims

1. An inner pipe having an orifice on its outer surface portion, from which refrigerant flows out, An outer tube that houses the inner tube, having an inner diameter larger than the outer diameter of the inner tube, Equipped with, The aforementioned outer tube is A first member extending in the same direction as the inner tube and forming a part of the outer tube, A second member extending in the same direction as the inner tube and combined with the first member to form the remaining portion of the outer tube, The first member and the second member each have a core material and a brazing material covering the outer circumferential surface portion of the core material, The orifice is facing the inner circumferential surface portion of the core material. distributor.

2. The outer tube has a cylindrical shape in which the inner diameter is larger than the outer diameter of the inner tube, The first member has an opening in a part of the cylindrical portion that opens the internal space of the cylindrical portion, The second member is fitted into the opening, and the portion that contacts the inner wall of the opening is covered with the brazing material. The distributor according to claim 1.

3. The outer tube has a cylindrical shape in which the inner diameter is larger than the outer diameter of the inner tube, The first member has a U-shape when viewed in a cross-section perpendicular to the cylindrical axis of the cylindrical portion. The second member has a different U-shape, smaller than the U-shape of the first member when viewed in cross-section, and is fitted inside the U-shaped opening of the first member. The distributor according to claim 1.

4. The first member has a chamfered portion at the corner formed by the end and inner surface of the U-shape when viewed in cross-section. The distributor according to claim 3.

5. The U-shape of the first member, when viewed in cross-section, has a shape in which the opening becomes larger towards the open end. The distributor according to claim 3 or 4.

6. The second member has a chamfered portion at the corner formed by the end and outer surface of the other U-shape when viewed in the cross-section. The distributor according to claim 3 or 4.

7. The first member has a protrusion on the inner surface of each of the two opposing side wall portions of the U-shape when viewed in cross-section, which, when the second member is fitted into it, abuts against the other U-shaped end of the second member when viewed in cross-section, and determines the position of that end. The distributor according to claim 3 or 4.

8. The aforementioned protrusion extends in the direction in which the cylindrical axis of the cylindrical portion extends. The distributor according to claim 7.

9. The first member has steps on the inner surfaces of the two opposing side wall portions of the U-shape when viewed in the cross-section, and the distance between the portions of the two side wall portions on the opening side of the steps is large. Each of the other U-shaped ends of the second member, as viewed in the cross-section, abuts against each of the steps. The distributor according to claim 3 or 4.

10. A distributor according to claim 1 or 2, Multiple refrigerant pipes connected to the distributor, through which the refrigerant is distributed and through which the heat of the refrigerant is transmitted, Multiple fins attached to the aforementioned multiple refrigerant pipes, Equipped with, heat exchanger.

11. Assembling the outer tube by combining a first member that forms a part of the outer tube and a second member that forms the remaining part of the outer tube and has brazing material provided in the part that becomes the joint when combined with the first member, further arranging an inner tube having an orifice on its outer surface and having an outer diameter smaller than the inner diameter of the outer tube in the internal space of the outer tube, and arranging the core material of the first member and the second member, respectively, with the orifice facing the inner surface portion of the core material, A step of brazing the second member to the first member by heating the assembled outer tube and the inner tube placed in the internal space of the outer tube at a temperature higher than the melting point of the brazing material to melt the brazing material, Equipped with, A method for manufacturing a distributor.

12. In the process of assembling the outer tube by combining the first member and the second cylindrical member, the second member is lightly press-fitted into the first member, thereby joining them together. A method for manufacturing a distributor according to claim 11.

13. The outer tube has a cylindrical shape with an inner diameter larger than the outer diameter of the inner tube, The first member has an opening in a part of the cylindrical portion, The second member is fitted into the opening, In the process of assembling the outer tube by combining the first member and the second member, the second member is lightly press-fitted into the opening of the first member, thereby joining them together. A method for manufacturing a distributor according to claim 12.

14. The outer tube has a cylindrical shape in which the inner diameter is larger than the outer diameter of the inner tube, The first member has a U-shape when viewed in a cross-section perpendicular to the cylindrical axis of the cylindrical portion. The second member, when viewed in cross-section, is smaller than the U-shape of the first member and has another U-shape that can be fitted inside the U-shaped opening of the first member. In the process of assembling the outer tube by combining the first member and the cylindrical second member, the second member is lightly press-fitted into the U-shaped opening of the first member, thereby joining them together. A method for manufacturing a distributor according to any one of claims 11 to 13.

15. In the step of brazing the second member to the first member, A jig that holds the first member and the second member in a combined state is attached to the assembled outer tube, and the outer tube to which the jig is attached is heated to the temperature. A method for manufacturing a distributor according to claim 11 or 12.

16. The method for manufacturing a distributor according to claim 11 or 12 is provided, Prior to the step of brazing the second member to the first member, the process includes a step of assembling a plurality of refrigerant pipes, each with a plurality of fins attached, to the combined first and second members. A method for manufacturing a heat exchanger.