Header pipe, heat exchanger, air conditioning device, and method for manufacturing header pipe

Abstract

The upper header tube (11) according to the present disclosure is connected to a plurality of heat exchanger tubes arrayed parallel to each other to constitute a heat exchanger together with the heat exchanger tubes. Furthermore, the upper header tube (11) comprises: a first member (21) provided with a bottom plate (23) and a pair of side plates (24) that is erected at both ends of the bottom plate (23); a second member (22) that is disposed at a position separated from the bottom plate (23), held between the pair of side plates (24), and brazed to the first member (21); and a plurality of claw members (28) that are formed at each end of the pair of side plates (24) of the first member (21), and that are bent from the side plates (24) to face the second member (22). The claw members (28) are narrower toward the leading end in plan view.

Description

[Technical Field]

[0001] The present disclosure relates to a header pipe, a heat exchanger, an air conditioning apparatus, and a method for manufacturing a header pipe. [Background technology]

[0002] An air conditioner is a device that heats or cools indoor air by circulating a refrigerant between an indoor unit and an outdoor unit. Each of the indoor and outdoor units of an air conditioner is equipped with a heat exchanger. The heat exchanger is a device that exchanges heat between the refrigerant and the environment surrounding the indoor or outdoor unit. The heat exchanger includes a heat transfer tube group consisting of multiple heat transfer tubes and a header pipe connected to the heat transfer tube group.

[0003] Header pipes that constitute heat exchangers are known to be formed by brazing multiple members. For example, the header pipes provided in the heat exchanger described in Patent Document 1 are formed by brazing a second member to a first member having a bottom plate and a pair of side plates. The side plates have claw members formed on the ends facing the second member, and the claw members are bent so as to contact the second member. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-95086 Summary of the Invention [Problem to be solved by the invention]

[0005] Air conditioners need to be configured so that the refrigerant circulating within the air conditioner does not leak along the way. Therefore, in the header pipe described in Patent Document 1, the first member and the second member need to be airtightly joined to prevent refrigerant leakage.

[0006] However, the header pipe described in Patent Document 1 has a problem in that springback occurs after bending the claw members, opening a gap between the claw members and the second member at the tip of the claw members. As a result, during the brazing process, the molten brazing material may flow downward through the gap between the claw members and the second member, preventing the brazing material from reaching the joint between the first member and the second member. As a result, the airtightness of the joint between the first member and the second member may be impaired. Thus, the header pipe described in Patent Document 1 has a problem in that it is difficult to ensure airtightness of the joint between the first member and the second member during the manufacturing process.

[0007] The present disclosure has been made in consideration of the above-mentioned problems, and provides a header pipe that is constructed by bending the claw members of one member and overlapping it with the other member, fixing the other member to the one member, and then brazing the two together, making it easy to ensure airtightness during the manufacturing process.

[0008] The present disclosure also provides a heat exchanger and an air conditioner including the header pipe, and a method for manufacturing the header pipe. [Means for solving the problem]

[0009] In order to achieve the above object, a header pipe according to the present disclosure is connected to a plurality of heat transfer tubes arranged in parallel to each other, and together with the plurality of heat transfer tubes, constitutes a heat exchanger. The header pipe according to the present disclosure includes a bottom plate and a pair of side plates erected on both ends of the bottom plate. The groove-shaped cross section is formed by and a first member disposed at a position spaced apart from the bottom plate, sandwiched between a pair of side plates, and brazed to the first member. , closing the groove-shaped cross section R Flat The first member includes a second member and a plurality of claw members formed at the end of each of a pair of side plates of the first member, the claw members being bent relative to the side plates and facing the second member. Furthermore, the claw members have a width that narrows toward the tip in a planar shape. The gap between the claw member and the second member and the gap between the side plate of the first member and the second member are filled with brazing material. are. [Effects of the Invention]

[0010] In the header pipe according to the present disclosure, during the brazing process, the brazing material applied in advance to the surfaces of the claw members that contact the second member melts and flows down, resulting in a larger bulge of the brazing material remaining at the tips of the claw members, making it easier for the brazing material to come into contact with the second member. This prevents the occurrence of breaks in the brazed joint due to dripping brazing material. As a result, the present disclosure provides a header pipe that makes it easy to ensure airtightness during the manufacturing process. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is an explanatory diagram illustrating a basic configuration of an air conditioning apparatus according to an embodiment of the present disclosure. [Figure 2A] FIG. 2 is a front view showing the basic configuration of a heat exchanger included in the air conditioning apparatus shown in FIG. 1. [Figure 2B] Side view of the heat exchanger [Figure 3A] FIG. 2C is a cross-sectional view of an upper header tube provided in the heat exchanger shown in FIGS. 2A and 2B, cut along the plane indicated by line II in FIG. 2A. [Figure 3B] FIG. 2C is a longitudinal cross-sectional view showing a part of the upper header pipe cut along the plane shown by line II-II in FIG. [Figure 4A] FIG. 4 is a perspective view showing the outer shape of a first member constituting an upper header pipe included in the heat exchanger shown in FIGS. 2A and 2B before a second member is assembled to the first member and before the claw members are bent. [Figure 4B] FIG. 10 is a perspective view showing a state in which the second member is assembled to the first member; [Figure 4C] 4B is an enlarged view of the claw member of the first member as viewed from the direction indicated by the arrow A in FIG. 4A; [Figure 5] FIG. 10 is a cross-sectional view of the upper header pipe, illustrating the function of the claw members; [Figure 6] Cross-sectional view of the upper header tube after brazing is completed, following the example in Figure 5 [Figure 7A]FIG. 4D is a front view showing the shape of a test piece simulating the claw member included in the first member shown in FIGS. 4A to 4C before an experiment. [Figure 7B] Side view showing the shape of the test piece after the experiment [Figure 7C] A graph showing the relationship between the ratio of the diameter of the arc at the tip of the test piece to the width of the base of the test piece and the height of the lump of brazing material formed at the tip of the test piece. [Figure 7D] A front view showing the shape of another test piece before the experiment [Figure 7E] Side view showing the shape of another test piece after the experiment [Figure 8A] FIG. 10 is a plan view showing the shape of a claw member according to a first modified example of the present disclosure. [Figure 8B] FIG. 10 is a plan view showing the shape of a claw member according to a second modification of the present disclosure. [Figure 9] FIG. 6 is a cross-sectional view showing the structure of an upper header pipe according to a third modified example of the present disclosure, following the example shown in FIG. 5. [Figure 10A] FIG. 13 is a perspective view showing the shape of a first member according to Modification 4. [Figure 10B] FIG. 10 is a perspective view showing the shape of an end plate according to Modification 4. [Figure 10C] FIG. 10 is a perspective view showing a state in which an end plate is assembled to the first member. [Figure 10D] FIG. 10 is a perspective view showing a state in which an end plate and a second member are assembled to the first member and the claw member is further bent. [Figure 10E] FIG. 4D is an explanatory diagram showing the shapes of the hook members and the engagement grooves of the first member according to Modification 4, following FIG. 4C. [Figure 11] FIG. 4D is an explanatory diagram showing the shapes of the claw members and the notches included in the first member according to Modification 5, following FIG. 4C. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, the configurations and operations of a header pipe, a heat exchanger, and an air conditioning apparatus according to embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the same reference numerals are used in each drawing to designate the same or equivalent parts.

[0013] (Air conditioning equipment) FIG. 1 is an explanatory diagram showing the basic configuration of an air conditioner 1 according to an embodiment of the present disclosure. The air conditioner 1 is a device that adjusts the temperature of air in a room (not shown) that is the target of air conditioning, and functions as a heater or a cooler as necessary. As shown in FIG. 1, the air conditioner 1 includes an outdoor unit 2 and an indoor unit 3. A pipe 4 is provided between the outdoor unit 2 and the indoor unit 3, and a refrigerant circulates between the outdoor unit 2 and the indoor unit 3 through the pipe 4.

[0014] As shown in Fig. 1, the outdoor unit 2 and the indoor unit 3 each include a heat exchanger 5 and a fan 6. The heat exchanger 5 is a device that exchanges heat between the refrigerant passing through the heat exchanger 5 and the environment around the heat exchanger 5. The fan 6 is a blower that blows air around the heat exchanger 5 onto the heat exchanger 5 to promote heat exchange.

[0015] As shown in Fig. 1, the outdoor unit 2 is equipped with a compressor 7, a four-way valve 8, and an expansion valve 9. The compressor 7 is a compression device that adiabatically compresses gaseous refrigerant. The four-way valve 8 is a valve device that switches the direction in which the refrigerant flows in the pipe 4. The expansion valve 9 is a device that decompresses the liquid refrigerant to vaporize it.

[0016] In the state shown in Fig. 1, the four-way valve 8 is set to a state in which the air conditioner 1 functions as a heater. In this state, the refrigerant, compressed in the compressor 7 and whose temperature has increased, flows into the heat exchanger 5 of the indoor unit 3 and releases heat to the indoor air. After passing through the heat exchanger 5 of the indoor unit 3, the refrigerant passes through the expansion valve 9 and flows into the heat exchanger 5 of the outdoor unit 2, where it absorbs heat from the outdoor air. The refrigerant then returns to the compressor 7. Note that if the setting of the four-way valve 8 is changed to reverse the refrigerant flow direction, heat is absorbed in the heat exchanger 5 of the indoor unit 3 and released in the heat exchanger 5 of the outdoor unit 2, causing the air conditioner 1 to function as a cooler.

[0017] (heat exchanger) 2A is a front view showing the basic configuration of heat exchanger 5, and FIG. 2B is a side view of heat exchanger 5. As shown in FIGS. 2A and 2B, heat exchanger 5 includes an upper header pipe 11, a first lower header pipe 12, and a second lower header pipe 13.

[0018] As shown in Fig. 2B, the first lower header pipe 12 has a first inlet / outlet port 14, and the second lower header pipe 13 has a second inlet / outlet port 15. The first inlet / outlet port 14 and the second inlet / outlet port 15 are pipe joints to which a pipe line 4 (not shown in Fig. 2B) is connected. The refrigerant flows in and out of the heat exchanger 5 through the first inlet / outlet port 14 and the second inlet / outlet port 15. Note that although a detailed description of the structure of the second lower header pipe 13 of the first lower header pipe 12 will be omitted, both have substantially the same structure.

[0019] 2B, a first heat transfer tube row 16 is disposed between the first lower header tube 12 and the upper header tube 11 to connect them together. A second heat transfer tube row 17 is disposed between the second lower header tube 13 and the upper header tube 11 to connect them together.

[0020] 2A , the first heat transfer tube array 16 includes a plurality of heat transfer tubes 18 arranged at equal intervals in the longitudinal direction of the first lower header tube 12 and the upper header tube 11. Flow paths (not shown) are formed inside the heat transfer tubes 18, and a refrigerant flows through these flow paths between the first lower header tube 12 and the upper header tube 11. The second heat transfer tube array 17 also includes a plurality of heat transfer tubes 18 arranged at equal intervals in the longitudinal direction of the second lower header tube 13 and the upper header tube 11. A refrigerant also flows between the second lower header tube 13 and the upper header tube 11 through the flow paths inside the heat transfer tubes 18.

[0021] 2A and 2B, a plurality of heat transfer fins 19 are arranged at equal intervals between the upper header tube 11 and the first and second lower header tubes 12 and 13. The heat transfer fins 19 are thin metal plates and are physically connected to the first and second heat transfer tube rows 16 and 17. The provision of the heat transfer fins 19 promotes heat transfer between the refrigerant flowing in the first and second heat transfer tube rows 16 and 17 and the surrounding air.

[0022] With the above configuration, when the refrigerant flows into the first lower header pipe 12 through the first inlet / outlet port 14, the refrigerant that flows into the first lower header pipe 12 flows through the heat transfer tubes 18 that constitute the first heat transfer tube array 16 and moves to the upper header pipe 11. The refrigerant that moves to the upper header pipe 11 flows through the heat transfer tubes 18 that constitute the second heat transfer tube array 17 and moves to the second lower header pipe 13. The refrigerant that moves to the second lower header pipe 13 passes through the second inlet / outlet port 15 and is sent to the outside. When the refrigerant flows into the second lower header pipe 13 through the second inlet / outlet port 15, the refrigerant moves in the reverse direction from the above, that is, passes through the second heat transfer tube array 17, the upper header pipe 11, the first heat transfer tube array 16, and the first lower header pipe 12 in that order. The refrigerant that moves to the first lower header pipe 12 is then sent to the outside through the first inlet / outlet port 14.

[0023] In this way, the refrigerant passing through the heat exchanger 5 passes through the inside of the heat transfer tube 18. While the refrigerant passes through the inside of the heat transfer tube 18, heat exchange occurs between the refrigerant and the air surrounding the heat exchanger 5.

[0024] (Upper header pipe) Fig. 3A is a horizontal cross-sectional view of the upper header pipe 11 taken along the plane indicated by line II in Fig. 2A. Fig. 3B is a vertical cross-sectional view of a portion of the upper header pipe 11 taken along the plane indicated by line II-II in Fig. 2B. As mentioned above, the upper header pipe 11 is an example of a header pipe according to the present disclosure.

[0025] As shown in FIG. 3A , the upper header pipe 11 includes a first member 21 and a second member 22, which are joined by brazing. The first member 21 includes a bottom plate 23 and a pair of side plates 24 erected at both ends of the bottom plate 23, and is a metal component formed into a groove shape as a whole. The second member 22 is a metal component disposed at a position spaced apart from the bottom plate 23 of the first member 21 and sandwiched between the pair of side plates 24 of the first member 21. In short, the second member 22 is a component corresponding to a cover for the groove formed by the first member 21. Also, as shown in FIG. 3A , a corrugated plate 25 is disposed in the internal space of the upper header pipe 11, i.e., between the first member 21 and the second member 22. Furthermore, a cylindrical protrusion 26 is formed on the inner surface of the side plate 24 of the first member 21. The specific shapes and functions of the corrugated plate 25 and the protrusion 26 will be described later.

[0026] 3A, insertion holes 27a and 27b are formed in the bottom plate 23 of the first member 21. Ends of the heat transfer tubes 18 that make up the first heat transfer tube array 16 are inserted into the insertion hole 27a and joined by brazing. Ends of the heat transfer tubes 18 that make up the second heat transfer tube array 17 are inserted into the insertion hole 27b and joined by brazing.

[0027] 3A, the side plate 24 of the first member 21 has a claw member 28 at its end. The claw member 28 is bent from the side plate 24 to face the second member 22. The second member 22 is sandwiched between the corrugated plate 25 and the claw member 28.

[0028] As shown in Fig. 3B, an end plate 29 is disposed at the left end in the longitudinal direction of the upper header pipe 11. Furthermore, fitting holes 30, 31 are formed in the bottom plate 23 and the second member 22, respectively, and the end of the end plate 29 is fitted into the fitting holes 30, 31. Note that Fig. 3B shows a vertical cross section near the left end of the upper header pipe 11 in Fig. 2A. The area near the right end of the upper header pipe 11 is configured similarly to the area near the left end, and an end plate 29 is also disposed at the right end of the upper header pipe 11 in the longitudinal direction.

[0029] As described above, the corrugated plate 25 is disposed between the first member 21 and the second member 22. The corrugated plate 25 is formed in a corrugated shape, as shown in FIG. 3B . The provision of the corrugated plate 25 divides the interior of the upper header pipe 11 into pairs of adjacent insertion holes 27a, 27b. Therefore, the refrigerant that flows into the upper header pipe 11 moves within the compartments divided by the corrugated plate 25. For example, the refrigerant that flows into a compartment through a heat transfer tube 18 fixed to an insertion hole 27a flows into the heat transfer tube 18 fixed to an insertion hole 27b adjacent to the insertion hole 27a without flowing into other compartments.

[0030] 3A and 3B, the corrugated plate 25 is engaged with the protruding portions 26, thereby restricting longitudinal movement of the upper header pipe 11. The diameter of the protruding portions 26 is set equal to the radius of curvature of the curved portion of the corrugated plate 25, and the protruding portions 26 are arranged at the same pitch as the insertion holes 27a and 27b. Therefore, simply by engaging the corrugated plate 25 with the protruding portions 26, the corrugated plate 25 is correctly positioned with respect to the insertion holes 27a and 27b. Furthermore, as described above, the second member 22 is sandwiched between the corrugated plate 25 and the claw members 28.

[0031] The corrugated plate 25 may also be omitted. Also, in order to prevent the second member 22 from dropping toward the bottom plate 23 of the first member 21 across the longitudinal direction of the upper header pipe 11, multiple end plates 29, i.e., three or more end plates 29, may be arranged in the longitudinal direction of the upper header pipe 11 to divide the interior of the upper header pipe 11 into multiple compartments.

[0032] (1st and 2nd members) Fig. 4A is a perspective view showing the outer shape of first member 21 that constitutes upper header pipe 11. Fig. 4B is a perspective view showing a state in which second member 22 is assembled to first member 21. Fig. 4C is an enlarged arrow view of claw member 28 provided on first member 21, viewed from the direction indicated by arrow A in Fig. 4A.

[0033] As shown in FIG. 4A, a plurality of claw members 28 are formed at the end of the side plate 24 of the first member 21. Then, as shown in FIG. 4B, after the second member 22 is assembled to the first member 21, the claw members 28 are bent and abutted against the second member 22. As shown in FIG. 4C, the planar shape of the claw members 28 is such that the width is greatest at the base, i.e., the portion connected to the side plate 24. The width narrows toward the tip, i.e., the portion farthest from the side plate 24. The contour of the tip of the claw members 28 is shaped like an arc. In this specification, the planar shape of the claw members 28 refers to the shape shown in FIG. 4C. The length direction of the claw members 28 refers to the direction from the base to the tip of the claw members 28. The width direction of the claw members 28 refers to the direction perpendicular to the length direction in the planar shape shown in FIG. 4C.

[0034] (Action of the claw members) FIG. 5 is a cross-sectional view of the upper header pipe 11. The function of the claw members 28 will now be described with reference to FIG. 5. In manufacturing the heat exchanger 5, after assembling the various components, the heat exchanger 5 is placed in a heating furnace and heated to braze the components together. Because heating furnaces generally have height limitations, the heat exchanger 5 is brazed with the heat exchanger 5 lying on its side. That is, the heat exchanger 5 is placed in the heating furnace with the longitudinal axes of the heat transfer tubes 18 horizontal. In short, the heat exchanger 5 is brazed with the upper header pipe 11 in the position shown in FIG. 5. The first member 21 and the second member 22 are clad with brazing material in advance.

[0035] When the heat exchanger 5 is heated in a heating furnace (not shown), the molten brazing filler metal in the gap between the claw members 28 above the first member 21 and the second member 22 in FIG. 5 flows down due to gravity to the tip of the claw member 28, i.e., the portion indicated by the symbol P in FIG. 5. As described above, the claw members 28 are wide at their bases and narrow at their tips. Therefore, the brazing filler metal in the wide portion of the base of the claw member 28 is concentrated in the narrow portion of the tip of the claw member 28. As a result, a large lump of molten brazing filler metal is formed and raised at the tip of the claw member 28. Therefore, even if springback occurs after bending the claw members 28 and the gap between the tip of the claw member 28 and the second member 22 widens, the lump of brazing filler metal is held between the tip of the claw member 28 and the second member 22. Then, capillary action occurs in the gap between the base of the claw member 28 and the second member 22, and the brazing material that has been pre-clad on the inner and outer surfaces of the second member 22 and the inner surface of the side plate 24 and that has melted due to heating flows into the gap. As a result, the gap between the base of the claw member 28 and the second member 22 and the gap between the side plate 24 and the second member 22 are filled with brazing material. In this way, the brazing material is sufficiently distributed over the upper part of the first member 21 to the joint between the first member 21 and the second member 22. Note that capillary action also causes the brazing material to flow in the anti-gravity direction, so the brazing material flows into the gap between the first member and the second member from a wide area around the gap.

[0036] Meanwhile, in the gap between the claw member 28 at the bottom of the first member 21 and the second member 22 in FIG. 5 , gravity causes the molten brazing material to flow down and accumulate between the base of the claw member 28 and the second member 22, i.e., the portion indicated by the symbol Q in FIG. 5 . Because the base of the claw member 28 is less susceptible to deformation due to springback, the gap between the base of the claw member 28 and the second member 22 is generally small. Therefore, this portion is filled with the flowing brazing material. In addition, the brazing material clad on both sides of the side plate 24 flows into the gap between the first member 21 and the second member 22 by capillary action. As a result, the brazing material is sufficiently distributed at the joint between the first member 21 and the second member 22 at the top of the first member 21, even at the bottom end of the first member 21.

[0037] In order to achieve the above effect, that is, to spread the brazing material throughout the gap between the claw members 28 and the second member 22, it is necessary to perform brazing by placing the first member 21 and the second member 22 in a heating furnace with the length direction of the claw members 28, that is, the direction from the base to the tip of the claw members 28, facing vertically upward or vertically downward, as shown in Fig. 5. By selecting this position, gravity acts in the length direction of the claw members 28, so that the brazing material can be sufficiently spread throughout the gap between the claw members 28 and the second member 22.

[0038] When brazing is completed through the above process, the brazing material fills the gap between the claw member 28 and the second member 22. Then, as shown in FIG. 6, the brazing material accumulates at the tip of the claw member 28, i.e., at the portions indicated by the letters R and S in FIG. 6, forming a fillet. Also, as shown in FIG. 6, the fillet formed at the portion indicated by the letter S, i.e., the fillet formed at the tip of the claw member 28 located at the lower position in FIG. 6, is larger in size than the fillet formed at the portion indicated by the letter R, i.e., the fillet formed at the tip of the claw member 28 located at the upper position in FIG. 6. The length of the fillet formed at the portion indicated by the letter R is defined as l R The length of the fillet formed at the part indicated by the symbol S is l S Then, l R <l S This is because the brazing material cladding the outer surface of the second member 22 melts, flows downward, and accumulates in the portion indicated by the symbol S.

[0039] Thus, according to this embodiment, the shape of the brazing fillet formed at the tip of one of the two claw members 28 arranged opposite each other in the width direction of the upper header pipe 11 can be made different from the size of the brazing fillet formed at the tip of the other.

[0040] (Comparative experiment) The effect of claw member 28 was verified through a comparative experiment, which will now be described. Fig. 7A is a front view showing the shapes of test piece 41, which simulates claw member 28, and jig 42 for holding test piece 41 before the experiment. Fig. 7B is a side view showing the shape of test piece 41 after the experiment, that is, after test piece 41 was heated in a heating furnace (not shown) to melt the brazing material.

[0041] The test piece 41 had a width W of 5 mm, a length L of 12 mm, and a thickness T of 3 mm. Its surface was smoothly finished, and a brazing filler metal layer with a thickness of 0.15 mm was formed on it. As shown in FIG. 7A, the tip of the test piece 41 was semicircular. In this experiment, the diameter D of the semicircular tip was changed to compare performance. That is, the performance of four types of test pieces 41 with diameters D of 1 mm, 2 mm, 3 mm, and 4 mm was compared. Note that the test piece 41 was held upright by the jig 42, but the jig 42 did not contact the surface of the test piece 41. Therefore, the behavior of the brazing filler metal melted on the surface of the test piece 41 was not affected by the jig 42.

[0042] As shown in Figure 7B, the brazing filler metal melted on the surface of test piece 41 concentrates at the narrow tip of test piece 41, forming a lump 43. Figure 7C shows the relationship between the value obtained by dividing the semicircular diameter D of the tip of test piece 41 by the width W of the base of test piece 41 (i.e., D / W) and the height H1 of lump 43 measured from the surface of test piece 41 for the four types of test piece 41 described above. As shown in Figure 7C, the height H1 of lump 43 increases as the D / W ratio increases, reaching 0.44 mm when D / W = 0.6, and decreasing beyond that. In other words, H1 is at its maximum when D / W = 0.6. Furthermore, when D / W is 0.4 or greater, sufficient height is obtained for lump 43, while when D / W is 0.2 or less, the height of lump 43 is insufficient. The width W of the base of the test piece 41 used in this experiment is 5 mm, so when D is 1, 2, 3, or 4 mm, D / W is 0.2, 0.4, 0.6, 0, or 8, respectively.

[0043] FIG. 7D is a front view showing the shape of the test piece 44 and jig 42 according to the comparative example before the experiment. FIG. 7E is a side view showing the shape of the test piece 44 after the experiment, i.e., after the test piece 44 was heated in a heating furnace (not shown) to melt the brazing filler metal. The test piece 44 had a width W of 5 mm, a length L of 12 mm, and a thickness T of 3 mm. Its surface was smooth and clad with a 0.15 mm thick brazing filler metal layer. The test piece 44 differs from the test piece 41 in that its width W does not change between its base and tip. As shown in FIG. 7E, the brazing filler metal melted on the surface of the test piece 44 also flows to the tip of the test piece 44, forming a lump 45. However, the height H2 of the lump 45 from the test piece 44 is only 0.36 mm. Therefore, by setting the D / W ratio to 0.4 or more, the brazing filler metal can be increased. The greater the amount of this protrusion, the greater the brazing margin.

[0044] In this way, in test piece 41, the molten brazing material concentrates in the narrowed portion of the tip of test piece 41, and therefore, when test piece 41 and test piece 44 are heated under the same conditions, a lump of brazing material 43 formed at the tip of test piece 41 rises higher than a lump of brazing material 45 formed at the tip of test piece 44. Therefore, if claw member 28 is formed in a flat shape so that its width narrows toward the tip, the molten brazing material can be collected at the tip of claw member 28 and raised higher. Note that when D / W is 0.4 or more, the brazing material concentrates at the tip of the claw, allowing the brazing material to be raised higher, but when D / W is 0.2 or less, the tip of the claw becomes too narrow, and the area where the brazing material accumulates spreads toward the base of the claw, reducing the raising effect.

[0045] (Variations 1 and 2) Fig. 8A is a plan view showing the shape of claw member 28 according to Variation 1 of the present disclosure. As shown in Fig. 8A, claw member 28 may have a constant width over a certain range continuing from the base connected to side plate 24, and the width may gradually decrease from the middle to reach a minimum at the tip.

[0046] 8B is a plan view showing the shape of claw member 28 according to Variation 2 of the present disclosure. As shown in Fig. 8B, claw member 28 may have a narrow base connected to side plate 24, a wider tip, and then a gradually narrower tip, reaching a minimum width. In this way, claw member 28 may have a narrow base in a planar shape.

[0047] (Variation 3) FIG. 9 is a cross-sectional view showing the structure of an upper header pipe 11 according to Modification 3 of the present disclosure, following FIG. 5 . As shown in FIG. 9 , the upper header pipe 11 has recesses 32 in the second member 22 and protrusions 33 at the tips of the claw members 28. The protrusions 33 are fitted into the recesses 32. By selecting this configuration, the molten brazing material is likely to accumulate in the hook-shaped gaps R between the protrusions 33 and the recesses 32 during the brazing process. Then, the brazing material accumulated in the gaps R spreads into the gap between the first member 21 and the second member 22 by capillary action. As a result, the occurrence of discontinuities in the brazed joint between the first member 21 and the second member 22 is suppressed.

[0048] (Variation 4) Fig. 10A is a perspective view showing the shape of first member 21 according to Modification 4, and Fig. 10B is a perspective view showing the shape of end plate 29 according to Modification 4. Fig. 10C is a perspective view showing the state in which end plate 29 is assembled to first member 21, and Fig. 10D is a perspective view showing the state in which end plate 29 and second member 22 are assembled to first member 21 and further claw member 28 is bent. Fig. 10E is an explanatory diagram showing the shapes of claw member 28 and engagement groove 51 provided in first member 21 according to Modification 4, following Fig. 4C.

[0049] In the above, an example was shown in which the end plate 29 is assembled to the upper header pipe 11 by fitting the ends of the end plate 29 into the fitting holes 30, 31 drilled in the bottom plate 23 and the second member 22. However, the means for assembling the end plate 29 to the upper header pipe 11 is not limited to the fitting holes 30, 31. Instead of the fitting holes 30, 31, as shown in FIG. 10A , fitting grooves 51 may be provided on the two opposing side plates 24, cut from the ends of the side plates 24 between two adjacent claw members 28 in the longitudinal direction of the first member 21. Furthermore, as shown in FIG. 10B , tabs 52 are provided on the ends of the end plate 29, and as shown in FIG. 10C , the end plate 29 is positioned relative to the first member 21 by inserting the tabs 52 into the fitting grooves 51 and engaging them. 10D, the second member 22 is placed on the end plate 29, and the claw members 28 are bent, whereby the end plate 29 is fixed to the first member 21 and the second member 22. As shown in FIG.

[0050] 10E, the width G1 of the mating groove 51 is equal to the distance between the two claw members 28 at their bases. As described above, the claw members 28 are tapered toward their tips, so the distance G2 between the two claw members 28 at their tips is wider than the distance between the two claw members 28 at their bases, and this distance is greater than the thickness of the end plate 29. Therefore, the claw members 28 function as guides when inserting the tabs 52 of the end plate 29 into the mating grooves 51. Therefore, the tabs 52 can be easily inserted into the mating grooves 51.

[0051] (Variation 5) FIG. 11 is an explanatory diagram showing the shapes of the claw members 28 and the notches 53 provided on the first member 21 according to Modification 5, following FIG. 4C . The shape of the interface between the side plate 24 and the claw members 28 is not limited to that shown in FIG. 4C . As shown in FIG. 11 , the notches 53 may be formed between the bases of the claw members 28 and the side plate 24, thereby structurally "separating" the claw members 28 from the side plate 24. Structurally "separating" the claw members 28 from the side plate 24 suppresses the springback phenomenon that occurs after bending the claw members 28. In other words, the bent claw members 28 are prevented from deforming in the direction of returning to their original shape due to the elasticity of the material, thereby preventing the gap between the claw members 28 and the second member from widening. As a result, the structural stability of the upper header pipe 11 is improved.

[0052] As described above, even if there is a small gap between the claw members 28 and the second member 22, the brazing material melted during the brazing process accumulates in the gap between the claw members 28 and the second member 22. Then, starting from there, the brazing material flows and accumulates sequentially at the joint between the first member 21 and the second member 22 due to capillary action. As a result, the occurrence of discontinuities in the brazed joint between the first member 21 and the second member 22 is suppressed. Therefore, it is easy to ensure airtightness of the upper header 11 during the manufacturing process.

[0053] However, the technical scope of the present disclosure is not limited to the above-described embodiments, and the present disclosure can be freely applied, modified, or improved within the scope of the technical ideas described in the claims.

[0054] The specific mechanical configuration of the header pipe according to the present disclosure is not limited by the specific configuration of the above-described upper header pipe 11. In particular, the header pipe according to the present disclosure is not limited to one that includes a corrugated plate 25. Furthermore, the specific shape of the claw members included in the header pipe according to the present disclosure is not limited by the specific shape of the above-described claw members 28.

[0055] The specific configuration of the heat exchanger according to the present disclosure is not limited to the specific configuration of the heat exchanger 5 described above. In particular, the heat exchanger according to the present disclosure is not limited to one including a first lower header pipe 12 and a second lower header pipe 13. Furthermore, the heat exchanger according to the present disclosure is not limited to one in which two header pipes are arranged spaced apart in the vertical direction. In the heat exchanger according to the present disclosure, the two header pipes may be arranged spaced apart in the horizontal direction. Furthermore, it is sufficient for the heat exchanger according to the present disclosure that at least one of the multiple header pipes is the header pipe according to the present disclosure described above.

[0056] The specific configuration of the air conditioner according to the present disclosure is not limited by the specific configuration of the above-described air conditioner 1. It is sufficient for the air conditioner according to the present disclosure to be equipped with the heat exchanger according to the present disclosure in either the indoor unit or the outdoor unit, and the other of the indoor unit or the outdoor unit may be equipped with a heat exchanger of a different type. Furthermore, the air conditioner according to the present disclosure may be equipped with components not exemplified above.

[0057] 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 illustrate 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 the meaning of equivalent disclosures are considered to be within the scope of the present disclosure.

[0058] This application is based on Japanese Patent Application No. 2022-037966, filed on March 11, 2022. The entire specification, claims, and drawings of Japanese Patent Application No. 2022-037966 are incorporated herein by reference. [Explanation of symbols]

[0059] REFERENCE SIGNS LIST 1 air conditioner, 2 outdoor unit, 3 indoor unit, 4 duct, 5 heat exchanger, 6 fan, 7 compressor, 8 four-way valve, 9 expansion valve, 11 upper header pipe, 12 first lower header pipe, 13 second lower header pipe, 14 first inlet / outlet port, 15 second inlet / outlet port, 16 first heat transfer tube row, 17 second heat transfer tube row, 18 heat transfer tube, 19 heat transfer fin, 21 first member, 22 second member, 23 bottom plate, 24 side plate, 25 corrugated plate, 26 protrusion, 27a, 27b insertion hole, 28 claw member, 29 end plate, 30, 31 fitting hole, 32 recess, 33 protrusion, 41, 44 test piece, 42 jig, 43, 45 block, 51 fitting groove, 52 tab, 53 cutout

Claims

1. A header tube connected to a plurality of heat transfer tubes arranged in parallel to each other and constituting a heat exchanger together with the plurality of heat transfer tubes, a first member having a groove-shaped cross section, the first member including a bottom plate and a pair of side plates erected on both ends of the bottom plate; a flat-plate-shaped second member that is disposed at a position spaced apart from the bottom plate, is sandwiched between the pair of side plates, and is brazed to the first member to close the channel-shaped cross section; a plurality of claw members formed at respective ends of the pair of side plates of the first member, the claw members being bent relative to the side plates and facing the second member; The claw member has a width that narrows toward the tip in a plan view, a gap between the claw member and the second member and a gap between the side plate of the first member and the second member are filled with brazing material; Header tube.

2. a protrusion protruding in a direction toward the second member is provided at a tip of the claw member, and a recess is provided in the second member; The protrusion is fitted into the recess. The header pipe according to claim 1 .

3. The width of the claw member narrows from the middle of the length of the claw member to the tip. The header pipe according to claim 1 or 2.

4. The claw member has a width that increases from a base portion connected to the side plate of the claw member to a midpoint in the length direction of the claw member, and a width that decreases from the midpoint to a tip of the claw member. The header pipe according to claim 1 or 2.

5. A header tube connected to a plurality of heat transfer tubes arranged in parallel to each other and constituting a heat exchanger together with the plurality of heat transfer tubes, a first member including a bottom plate and a pair of side plates erected on both ends of the bottom plate; a second member disposed at a position spaced apart from the bottom plate, sandwiched between the pair of side plates, and brazed to the first member; a plurality of claw members formed at respective ends of the pair of side plates of the first member, the claw members being bent relative to the side plates and facing the second member, The claw member is a header pipe whose width narrows toward the tip in a plan view, end plates for sealing longitudinal ends of the header pipes; The first member has a groove formed between two adjacent claw members, the groove being cut from an end of the side plate, A portion of the end plate is fitted into the fitting groove. Header tube.

6. A header tube connected to a plurality of heat transfer tubes arranged in parallel to each other and constituting a heat exchanger together with the plurality of heat transfer tubes, a first member including a bottom plate and a pair of side plates erected on both ends of the bottom plate; a second member disposed at a position spaced apart from the bottom plate, sandwiched between the pair of side plates, and brazed to the first member; a plurality of claw members formed at respective ends of the pair of side plates of the first member, the claw members being bent relative to the side plates and facing the second member, The claw member is a header pipe whose width narrows toward the tip in a plan view, a partition plate that partitions the inside of the header pipe; The first member has a groove formed between two adjacent claw members, the groove being cut from an end of the side plate, A portion of the partition plate is fitted into the fitting groove. Header tube.

7. a size of a brazing fillet formed at a tip of one of the two claw members arranged opposite to each other in the width direction of the header pipe is different from a size of a brazing fillet formed at a tip of the other claw member; The header pipe according to claim 1 or 2.

8. An end plate that seals the longitudinal end of the header pipe, the end plate being fixed to the first member and the second member. The header pipe according to claim 1 or 2.

9. A partition plate that divides the inside of the header pipe, the partition plate being fixed to the first member and the second member. The header pipe according to claim 1 or 2.

10. The side plate is provided with a mating groove, The partition plate is fitted into the fitting groove; The header pipe according to claim 9.

11. The end of the side plate is cut out at a portion adjacent to the base of the claw member of the side plate to form a cutout portion. The header pipe according to claim 1 or 2.

12. The tip of the claw member has an arc-shaped outline in plan view. The header pipe according to claim 1 or 2.

13. When the diameter of the arc-shaped outline in the planar shape of the tip of the claw member is represented by D and the width in the planar shape of the base of the claw member is represented by W, D / W is in the range of 0.4 or more and 0.8 or less. The header pipe according to claim 12.

14. The claw member is bent at a right angle to the side plate. The header pipe according to claim 1 or 2.

15. The header pipe according to claim 1 or 2; a plurality of heat transfer tubes connected to the header tube, heat exchanger.

16. An air conditioning apparatus comprising an indoor unit and an outdoor unit, and circulating a refrigerant between the indoor unit and the outdoor unit, At least one of the indoor unit and the outdoor unit is provided with the heat exchanger according to claim 15. Air conditioning equipment.

17. A first member having a bottom plate and a pair of side plates erected on both ends of the bottom plate; a second member disposed at a position spaced apart from the bottom plate, sandwiched between the pair of side plates, and brazed to the first member; a plurality of claw members formed at respective ends of the pair of side plates of the first member, the claw members being bent relative to the side plates and facing the second member, The claw member has a width that narrows toward the tip in a plan view, a gap between the claw member and the second member and a gap between the side plate of the first member and the second member are filled with brazing material, A method for manufacturing a header tube that is connected to a plurality of heat transfer tubes arranged in parallel to each other and that constitutes a heat exchanger together with the plurality of heat transfer tubes, comprising the steps of: The second member is assembled to the first member, and then the first member and the second member are placed in a heating furnace with the direction from the base portion to the tip of the claw member facing vertically upward or vertically downward, and brazed. Header pipe manufacturing method.

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