Heat exchanger, method for manufacturing same, and refrigeration device

Abstract

A heat exchanger (13) is provided with a first member (41), a second member (42), and a latch (43). The first member (41) is provided with a first hole (41a) and is made of aluminum. The second member (42) is provided with a second hole (42a) and is made of aluminum. The latch (43) penetrates the first hole (41a) and the second hole (42a). The latch (43) is fixed to the first member (41) and the second member (42). The latch (43) is made of an aluminum alloy having a manganese content of 1.5% or less and a copper content of 1.0% or less.

Description

Heat exchanger, its manufacturing method, and refrigeration device

[0001] The present disclosure relates to a heat exchanger used in a refrigeration device and a method for manufacturing the same.

[0002] The heat exchanger disclosed in Patent Document 1 (JP 2021-025718 A) has a stacked header. The stacked header has a plurality of plates. Some of the plates are coated with brazing material. The stacked plates are fixed by furnace brazing to obtain the stacked header.

[0003] During the furnace brazing process, the stack is susceptible to vibration. Plate misalignment due to vibration can reduce the reliability of the heat exchanger. To prevent such misalignment, the stack is temporarily fixed prior to furnace brazing. Various temporary fixation methods are available, including welding, tube expansion, and crimping. However, each method requires specialized equipment, the cost of which is added to the cost of the stack header and heat exchanger.

[0004] A heat exchanger according to a first aspect includes a first member, a second member, and a latch. The first member has a first hole and is made of aluminum. The second member has a second hole and is made of aluminum. The latch is disposed in the first hole and the second hole. The latch is fixed to the first member and the second member. The latch is made of an aluminum alloy having a manganese content of 1.5% or less and a copper content of 1.0% or less.

[0005] According to this configuration, the latch is made of an aluminum alloy containing 1.5% or less manganese and 1.0% or less copper. This reduces the latch's resistance to brazing material and galvanic corrosion, allowing it to be easily fixed to the first and second members. This eliminates the need for complex manufacturing processes such as welding, expanding, and crimping.

[0006] A heat exchanger according to a second aspect is the heat exchanger according to the first aspect, further comprising a stacked header, wherein at least one of the first member and the second member is a stacking plate included in the stacked header.

[0007] According to this configuration, the latch is used for assembling the stacked header, which makes assembly of the stacked header easy, thereby reducing the cost of the heat exchanger.

[0008] A heat exchanger according to a third aspect is the heat exchanger according to the first or second aspect, wherein the second hole is a screw hole, and the surface of the latch has a sawtooth shape that engages with the screw hole.

[0009] With this configuration, the latch engages with the screw hole, thereby firmly securing the first member and the second member together.

[0010] A fourth aspect of the present invention is a heat exchanger according to any one of the first to third aspects, wherein the first potential difference caused by contact between the latch and the first member and the second potential difference caused by contact between the latch and the second member are both 100 mV or less. This configuration makes it difficult for a galvanic current to flow between the latch and the first member or the second member. Therefore, metal corrosion is unlikely to occur around the latch.

[0011] A heat exchanger according to a fifth aspect is the heat exchanger according to any one of the first aspect to the fourth aspect, wherein the material of the latch is represented by a number in the 3000s or 4000s of the ISO aluminum alloy standard.

[0012] With this configuration, the latch and the first or second member are made of the same material, or the latch and the brazing material are made of the same material, which reduces the risk of galvanic corrosion at the contact points between the members, thereby improving the reliability of the heat exchanger.

[0013] A heat exchanger according to a sixth aspect is the heat exchanger according to the fifth aspect, wherein the aluminum alloy is one that is represented by a number in the 3000 series of the ISO aluminum alloy standard. The latch is brazed to both the first member and the second member.

[0014] With this configuration, the latch and the first or second member are made of the same material, so galvanic corrosion does not occur at the contact points between the members.

[0015] A heat exchanger according to a seventh aspect is the heat exchanger according to the fifth aspect, wherein the aluminum alloy is represented by a number in the 4000s according to the ISO aluminum alloy standard.

[0016] According to this configuration, the latch is made of brazing material, and therefore the galvanic current generated at the contact point between the members is negligibly small, making corrosion unlikely to occur.

[0017] A refrigeration device according to an eighth aspect includes the heat exchanger according to any one of the first to seventh aspects.

[0018] According to this configuration, a corrosion-resistant and inexpensive heat exchanger is installed in the refrigeration system, which results in a long lifespan and low cost for the refrigeration system.

[0019] A ninth aspect of the manufacturing method is a method for manufacturing a heat exchanger. In the manufacturing method, a first aluminum member having a first hole and a second aluminum member having a second hole are prepared. A latch is prepared, the latch being made of an aluminum alloy having a manganese content of 1.5% or less and a copper content of 1.0% or less. An assembly is created by placing the latch in the first hole and the second hole. The assembly is heated in a furnace to fix the latch to the first member and the second member.

[0020] According to this method, the latch is made of an aluminum alloy containing 1.5% or less manganese and 1.0% or less copper, which reduces the latch's resistance to brazing material and galvanic corrosion, allowing it to be easily fixed to the first and second members, eliminating the need for complex manufacturing processes such as welding, expanding, and crimping.

[0021] A tenth aspect of the manufacturing method is the ninth aspect of the manufacturing method, in which the second hole is a screw hole, and the latch is a bolt.

[0022] According to this configuration, the latch configured as a bolt engages with the second hole configured as a screw hole, thereby firmly fixing the first member and the second member together.

[0023] A manufacturing method according to an eleventh aspect is the manufacturing method according to the tenth aspect, in which the bolts are tightened with a tightening torque of 0.3 N·m or less.

[0024] This method reduces the tightening force of the bolt, so there is little risk of damaging the bolt.

[0025] A manufacturing method according to a twelfth aspect is the manufacturing method according to any one of the ninth aspect to the eleventh aspect, in which the assembly is placed on a conveyor before being heated in the furnace.

[0026] In this method, the assembly is placed on a conveyor, so that its transport through the furnace is stable.

[0027] A thirteenth aspect of the present invention relates to the manufacturing method of any one of the ninth to twelfth aspects, in which the material of the latch is represented by a number in the 3000 series of the ISO aluminum alloy standard. Before heating the assembly in a furnace, a brazing material is applied to the assembly.

[0028] According to this method, the latch and the first or second member are made of the same material, so galvanic corrosion does not occur at the contact points between the members.

[0029] A fourteenth aspect of the manufacturing method is the manufacturing method according to any one of the ninth to twelfth aspects, wherein the material of the latch is represented by a number in the 4000 series of the ISO aluminum alloy standard, and the latch melts when the assembly is heated in a furnace.

[0030] According to this method, the latch is made of brazing material, and therefore the galvanic current generated at the contact points between the components is negligibly small, making corrosion unlikely.

[0031] FIG. 1 is a schematic diagram of a refrigeration system 100. FIG. 2 is a schematic diagram of a heat source heat exchanger 13. FIG. 3 is a perspective view of the heat source heat exchanger 13. FIG. 4 is a perspective view of a stacked header. FIG. 5 is a perspective view of the entire first header 51. FIG. 6 is a perspective view of an end of the first header 51. FIG. 7 is a perspective view showing a connection point of a gas side pipe 61 in the first header 51. FIG. 8 is a perspective view of the entire second header 52. FIG. 9 is a perspective view showing holding points of a plurality of return pipes 81 in the second header 52. FIG. 10 is a schematic view of a manufacturing facility for the heat source heat exchanger 13. FIG. 11 is a schematic view showing a first step of a manufacturing method according to the first embodiment. FIG. 12 is a schematic view showing a second step of a manufacturing method according to the first embodiment. FIG. 13 is a schematic view showing a third step of a manufacturing method according to the first embodiment. FIG. 14 is a schematic view showing a first step of a manufacturing method according to a first modified example of the first embodiment. FIG. 15 is a schematic diagram showing a second step of a manufacturing method according to a first modified example of the first embodiment. FIG. 16 is a schematic diagram showing a third step of a manufacturing method according to a first modified example of the first embodiment. FIG. 17 is a schematic diagram showing a third modified example of the first embodiment. FIG. 18 is a schematic diagram showing a first step of a manufacturing method according to a second embodiment. FIG. 19 is a schematic diagram showing a second step of a manufacturing method according to the second embodiment. FIG. 20 is a schematic diagram showing a third step of a manufacturing method according to the second embodiment. FIG. 21 is a diagram illustrating a state in which the latch 43 has poor wettability with the brazing material 44. FIG. 22 is a diagram illustrating a state in which the latch 43 has medium wettability with the brazing material 44. FIG. 23 is a diagram illustrating a state in which the latch 43 has good wettability with the brazing material 44.

[0032] <Configuration common to each embodiment> (1) Overall configuration Fig. 1 is a schematic diagram of a refrigeration device 100. The refrigeration device 100 may be an air conditioner, a freezer, a refrigerator, a water heater, a floor heating device, or the like. The refrigeration device 100 has a heat source unit 10, a utilization unit 20, and a refrigerant communication pipe group 30. These constitute a refrigerant circuit that circulates the refrigerant. Furthermore, the refrigeration device 100 has a communication line 39.

[0033] (2) Detailed Configuration (2-1) Heat Source Unit 10 The heat source unit 10 is for obtaining cold or heat from a heat source. The heat source unit 10 has a heat source casing 105, a compressor 11, a four-way switching valve 12, a heat source heat exchanger 13, a heat source fan 14, a heat source expansion valve 15, an accumulator 16, a liquid shut-off valve 17, a gas shut-off valve 18, and a heat source control unit 19.

[0034] The compressor 11 draws in low-pressure gas refrigerant through a suction pipe 11a, compresses it, and discharges the generated high-pressure gas refrigerant from a discharge pipe 11b.

[0035] The four-way switching valve 12 forms the connections shown by the solid lines in the cold heat utilization operation, and forms the connections shown by the broken lines in the hot heat utilization operation.

[0036] The heat source heat exchanger 13 functions as a condenser in cold heat utilization operation. At this time, the heat source heat exchanger 13 receives high-pressure gas refrigerant from the gas side pipe 61 and discharges high-pressure liquid refrigerant from the liquid side pipe 71. On the other hand, the heat source heat exchanger 13 functions as an evaporator in hot heat utilization operation. At this time, the heat source heat exchanger 13 receives low-pressure gas-liquid two-phase refrigerant from the liquid side pipe 71 and discharges low-pressure gas refrigerant from the gas side pipe 61. The detailed structure of the heat source heat exchanger 13 will be described later.

[0037] The heat source fan 14 generates an airflow that passes through the heat source heat exchanger 13 , thereby promoting heat exchange in the heat source heat exchanger 13 .

[0038] The heat source expansion valve 15 reduces the pressure of the high-pressure liquid refrigerant to produce a low-pressure gas-liquid two-phase refrigerant.

[0039] The accumulator 16 separates the liquid component contained in the gas refrigerant and stores it in a container.

[0040] The liquid shutoff valve 17 and the gas shutoff valve 18 are closed by the installer when shutting off the refrigerant circuit.

[0041] The heat source control unit 19 acquires output values ​​from various sensors and controls various actuators.

[0042] (2-2) Usage Unit 20 The usage unit 20 is for providing cold or hot heat to a user. The usage unit 20 has a usage casing 205, a usage heat exchanger 23, a usage fan 24, and a usage control unit 29.

[0043] The utilization heat exchanger 23 functions as an evaporator in cold heat utilization operation, and functions as a condenser in hot heat utilization operation.

[0044] The utilization fan 24 generates an air flow that passes through the utilization heat exchanger 23, thereby promoting heat exchange in the utilization heat exchanger 23. Furthermore, when the refrigeration device 100 is an air conditioner, the utilization fan 24 delivers conditioned air to the user.

[0045] The usage control unit 29 acquires output values ​​from various sensors, controls various actuators, and communicates with the heat source control unit 19 .

[0046] (2-3) Refrigerant communication pipe group 30 The refrigerant communication pipe group 30 has a liquid communication pipe 31 and a gas communication pipe 32. The liquid communication pipe 31 connects the liquid shutoff valve 17 and the utilization heat exchanger 23. The gas communication pipe 32 connects the gas shutoff valve 18 and the utilization heat exchanger 23.

[0047] (2-4) Communication Line 39 The communication line 39 connects the heat source control unit 19 and the usage control unit 29. The heat source control unit 19 and the usage control unit 29 exchange commands, status, and data via the communication line 39.

[0048] 2 schematically shows the structure of the heat source heat exchanger 13 according to the first embodiment. The heat source heat exchanger 13 has a first header 51, a second header 52, a heat exchange section 53, a gas side pipe 61, a liquid side pipe 71, and a return pipe 81.

[0049] (1-1) First Header 51 The first header 51 is a stacked header having a plurality of stacked plates. The stacked plates are made of aluminum, and the material is typically one designated by a number in the 3000s in the ISO aluminum alloy standard. Aluminum alloys designated by a number in the 3000s are aluminum-manganese alloys, and examples thereof include 3003 and 3004.

[0050] The first header 51 has a first gas chamber 51a and a first liquid chamber 51b due to cavities or other features provided in the plate. A plurality of first gas chambers 51a and a plurality of first liquid chambers 51b may be provided. A portion of the plate functions as a first partition wall 51c that separates the first gas chamber 51a and the first liquid chamber 51b. A gas-side pipe 61 and a liquid-side pipe 71 are connected to the first header 51. The gas-side pipe 61 is connected to the first gas chamber 51a. The liquid-side pipe 71 is connected to the first liquid chamber 51b.

[0051] (1-2) Second Header 52 The second header 52, like the first header 51, is a stacked header having multiple plates stacked together. The material of the plates is typically represented by a number in the 3000s of the ISO aluminum alloy standard. The second header 52 has a second gas chamber 52a and a second liquid chamber 52b due to cavities or other features provided in the plates. Multiple second gas chambers 52a and multiple second liquid chambers 52b may be provided. A portion of the plate functions as a second partition wall 52c separating the second gas chamber 52a and the second liquid chamber 52b. A return pipe 81 is connected to the second header 52. The second gas chamber 52a and the second liquid chamber 52b are connected to each other via the return pipe 81.

[0052] (1-3) Heat Exchanger 53 The heat exchanger 53 has a plurality of refrigerant pipes 54 and a plurality of fins 55 attached to the refrigerant pipes 54. Each of the plurality of refrigerant pipes 54 connects the first gas chamber 51 a and the second gas chamber 52 a, or connects the first liquid chamber 51 b and the second liquid chamber 52 b.

[0053] 3 realistically shows the structure of the heat source heat exchanger 13. The heat exchange section 53 forms a wall that stands vertically as a whole, and is L-shaped in plan view.

[0054] (1-4) Surroundings of the Gas Side Pipe 61 Figure 4 shows the structure of the end portion of the first header 51. The first header 51 has a plurality of stacked aluminum alloy plates 58 and an aluminum alloy outer wall member 57 surrounding them. The outer wall member 57 is provided with a plurality of crimping claws 59. The crimping claws 59 restrain the plurality of plates 58 by being bent. At least a portion of the plurality of plates 58 and the outer wall member 57 is a clad material to which a rolled brazing material is applied. The plurality of plates 58 and the outer wall member 57 are fixed to each other by furnace brazing.

[0055] FIG. 5 shows the entire first header 51. From this figure, it can be seen that a gas-side pipe 61 and a liquid-side pipe 71 are connected to the first header 51. A cover 56 that forms a refrigerant flow path by covering multiple plates 58 is provided around the gas-side pipe 61. As shown in FIG. 6, the cover 56 is restrained to the plates 58 by latches 56a before furnace brazing. The latches 56a are threaded bolts. The latches 56a are used to prevent misalignment between the cover 56, plates 58, and outer wall member 57 during furnace brazing.

[0056] As shown in FIG. 7 , a sleeve 62, a bracket 63, and a latch 64 are provided at the connection point between the cover 56 and the gas side pipe 61. An opening is provided in the cover 56 where the sleeve 62 is installed, allowing refrigerant to pass between the gas side pipe 61 and the first header 51 through this opening. The sleeve 62 is a clad material and secures the cover 56 and the gas side pipe 61 to each other by furnace brazing. The bracket 63 is restrained by a latch 64 to both the cover 56 and the sleeve 62 before furnace brazing. The latch 64 is a threaded bolt. The latch 64 prevents the cover 56 and the sleeve 62 from shifting in position during furnace brazing.

[0057] (1-5) Surroundings of the Liquid Side Tube 71 Returning to FIG. 5 , a tube holding plate 72 is provided around the liquid side tube 71 connected to one end of the first header 51. The tube holding plate 72 is restrained to the first header 51 by a latch 73 before furnace brazing. The latch 73 is a bolt having a thread. The latch 73 is used to prevent misalignment between the tube holding plate 72 and the first header 51 during furnace brazing.

[0058] (1-6) Surroundings of the Turn-Back Pipe 81 Referring again to FIG. 4, the structure of the second header 52 is also shown. The structure of the second header 52 is similar to that of the first header 51.

[0059] 8 shows the entire second header 52. From this figure, it can be seen that a plurality of return pipes 81 are connected to the second header 52. A plurality of tube holding plates 82 are provided around the return pipes 81. The tube holding plates 82 are restrained to the plates 58 by latches 83, such as bolts, before the furnace brazing. The latches 83 are threaded bolts. The latches 83 are intended to prevent misalignment between the tube holding plates 82 and the plates 58 during the furnace brazing.

[0060] 9, a tube holding plate 84 is also provided to collectively hold a plurality of folded tubes 81. The tube holding plate 84 is restrained to the plate 58 by latches 83 such as bolts before the furnace brazing, thereby preventing misalignment between the tube holding plate 84 and the plate 58.

[0061] (2) Manufacturing Method Fig. 10 shows a manufacturing facility for the heat source heat exchanger 13. First, a first member 41, a second member 42, and a latch 43 are prepared on a mounting table 91. The first member 41 and the second member 42 are fixed to each other by brazing in a furnace, and at least one of them is a clad material.

[0062] The first member 41 refers to the cover 56 around the gas side pipe 61, the pipe holding plate 72 around the liquid side pipe 71, and the pipe holding plate 82 around the return pipe 81, etc.

[0063] The second member 42 refers to the sleeve 62 around the gas side pipe 61, the plate 58, and in some cases the cover 56, the plate 58 around the liquid side pipe 71, and the plate 58 around the return pipe 81, etc.

[0064] The latch 43 refers to the latch 56 a and latch 64 around the gas side pipe 61 , the latch 73 around the liquid side pipe 71 , and the latch 83 around the return pipe 81 .

[0065] 11 to 13 show a manufacturing method of the first embodiment. FIG. 11 shows the first step of the manufacturing method. A first hole 41a is provided in a first member 41. The first hole 41a penetrates the first member 41. The first member 41 is a clad material, in other words, a plate with a brazing material 44 installed therein. A second hole 42a is provided in a second member 42. The second hole 42a is configured as a through hole penetrating the second member 42. The second hole 42a is configured as a screw hole. The latch 43 is used to temporarily fasten the first and second members together. The latch 43 is configured as a bolt. The surface of the latch 43, which is a bolt, has a sawtooth thread 43a that engages with the second hole 42a, which is a screw hole. The latch 43 is made of an aluminum alloy containing 1.5% or less manganese and 1.0% or less copper. The manganese content of the latch 43 may be 1.0% or less. In this embodiment, the material of the latch 43 is one designated by a number in the 3000s of the ISO aluminum alloy standard. Aluminum alloys designated by a number in the 3000s are aluminum-manganese alloys, and examples thereof include 3003 and 3004.

[0066] A first potential difference V1 is generated when the latch 43 and the first member 41 come into contact with each other. A second potential difference V2 is generated when the latch 43 and the second member 42 come into contact with each other. Both the first potential difference V1 and the second potential difference V2 are 100 mV or less.

[0067] 12 shows the second step of the manufacturing method. A latch 43 is placed in the first hole 41 a and the second hole 42 a. Next, the bolt that constitutes the latch 43 is tightened to create the assembly 40. The tightening torque value when tightening the bolt is 0.3 N·m or less.

[0068] 10, the assembly 40 is placed on a conveyor 92. The conveyor 92 slowly moves the assembly 40 through a furnace 93. The assembly 40 is heated in the furnace 93, whereby furnace brazing is performed.

[0069] 13 shows the third step of the manufacturing method. The brazing material 44 melts from the cladding material and adheres the latch 43 to the first and second members 41, 42. The assembly 40 is then cooled outside of the furnace 93, whereupon the latch 43 is secured to the first and second members 41, 42.

[0070] (3) Features (3-1) Generally, when brazing a base material, it is necessary for the base material and the brazing material to have good "wettability." Wettability refers to the affinity between the base material and the brazing material. FIGS. 21 to 23 are diagrams illustrating the wettability of the base material, i.e., a latch 43, with a brazing material 44. Wettability can be observed as the contact angle θ between the solid latch 43 and the liquid brazing material 44. FIG. 21 shows a state in which the wettability between the latch 43 and the brazing material 44 is poor, with the contact angle θ being a large value of 180°. FIG. 22 shows a state in which the wettability between the latch 43 and the brazing material 44 is moderate, with the contact angle θ being a smaller value of 90°. FIG. 23 shows a state in which the wettability between the latch 43 and the brazing material 44 is good, with the contact angle θ being an even smaller value of less than 90°.

[0071] When the base material has a low manganese content, the wettability of the brazing material is improved when placed on it. On the other hand, when the base material has a high manganese content, the oxide film formed on the base material becomes stronger, resulting in poor wettability. The material of the latch 43 is designated by a number in the 3000 series of the ISO aluminum alloy standard. Aluminum alloys designated by numbers in the 1000, 3000, and 4000 series have lower manganese contents than aluminum alloys in the 2000 and 5000 series. Therefore, the use of an aluminum alloy in the 3000 series improves the wettability of the latch 43. The latch 43 is also made of an aluminum alloy with a manganese content of 1.5% or less and a copper content of 1.0% or less. This manganese content of 1.5% or less is sufficiently low to ensure wettability. When the manganese content of the latch 43 is 1.0% or less, the wettability is further improved.

[0072] Therefore, the latch 43 is less likely to repel the brazing material or cause galvanic corrosion, and is therefore easily fixed to the first member 41 and the second member 42. This eliminates the need for complex processes such as welding, expanding, and crimping in the manufacturing process. This in turn may prevent the need for dedicated equipment for these complex processes, which increases the cost of the heat exchanger.

[0073] (3-2) The latch 43 is used for assembling the stacked header. Therefore, the stacked header can be easily assembled, and the cost of the heat source heat exchanger 13 can be reduced.

[0074] (3-3) The latch 43, which is a bolt, engages with the second hole 42a, which is a screw hole, thereby firmly fixing the first member 41 and the second member 42 together.

[0075] (3-4) The latch 43 and the first member 41 or the second member 42 are made of the same material. Therefore, galvanic corrosion does not occur at the contact points between the members.

[0076] (3-5) The tightening torque required to tighten the latch 43, which is a bolt, is small, at 0.3 N·m or less. Therefore, there is little risk of damaging the bolt, which is made of a material with poor hardness.

[0077] (3-6) In the manufacture of the heat-source heat exchanger 13, the assembly 40 is placed on a conveyor 92. The conveyor 92 is a vibration source, which may induce misalignment between the components that make up the assembly 40. However, the assembly 40 is temporarily fixed with latches 43, which prevents misalignment, so transportation through the furnace is unlikely to adversely affect the quality of the heat-source heat exchanger 13.

[0078] (4) Modifications Modifications of the first embodiment will be described below. A plurality of modifications may be combined.

[0079] (4-1) First Modification In the first embodiment, the second hole 42a is configured as a screw hole. Also, the latch 43 is configured as a bolt. However, instead of this, the second hole 42a does not have to be a screw hole. Alternatively, the latch 43 may be configured as a rod without threads. Alternatively, both may be used.

[0080] 14 to 16 show a manufacturing method according to a first modification of the first embodiment. Fig. 14 shows the first step of the manufacturing method. It can be seen that the second hole 42a is not a threaded hole, and the latch 43 is an unthreaded rod.

[0081] 15 shows the second step of the manufacturing method. The latch 43 is placed in the first hole 41 a and the second hole 42 a. By appropriately setting the diameters of the first hole 41 a and the second hole 42 a, the clearance can be reduced, thereby preventing the first member 41 and the second member 42 from shifting out of position.

[0082] 16 shows the third step of the manufacturing method. The brazing material 44 melts from the cladding material and adheres the latch 43 to the first and second members 41, 42. The assembly 40 is then cooled outside of the furnace 93, whereupon the latch 43 is secured to the first and second members 41, 42.

[0083] (4-2) Second Modification In the first embodiment, what contributes to furnace brazing is the brazing material 44 applied to the first member 41 or the second member 42 configured as a clad material. Alternatively, the first member and the second member 42 may both be prepared as bare materials, and brazing materials separate from the first member and the second member may be placed at the joint between the two.

[0084] (4-3) Third Modification In the first embodiment, the second hole 42a is configured as a through hole that penetrates the second member 42. Alternatively, as shown in FIG. 17, the second hole 42a may be configured as a recess having a dead end.

[0085] Second Embodiment (1) Configuration The second embodiment is very similar in structure to the first embodiment, but differs in materials. The manufacturing method according to the second embodiment will be described below, and the differences in materials will also be mentioned.

[0086] 18 to 20 show a manufacturing method according to the second embodiment. Fig. 18 shows the first step of the manufacturing method. A first hole 41a is formed in the first member 41. A second hole 42a is formed in the second member 42. The second hole 42a is configured as a screw hole. The first member 41 and the second member 42 are bare members, in other words, plates on which no brazing material 44 is provided. The latch 43 is configured as a bolt.

[0087] As in the first embodiment, the latch 43 is formed from an aluminum alloy containing 1.5% or less manganese and 1.0% or less copper. However, unlike the first embodiment, the material of the latch 43 in this embodiment is represented by a number in the 4000s of the ISO aluminum alloy standard. In other words, the material of the latch 43 is a brazing material. Aluminum alloys represented by a number in the 4000s are aluminum-silicon alloys, and an example of such an alloy is 4043.

[0088] 19 shows the second step of the manufacturing method. A latch 43 is placed in the first hole 41 a and the second hole 42 a. Next, the bolt that constitutes the latch 43 is tightened to create the assembly 40. The tightening torque value when tightening the bolt is the same as in the first embodiment.

[0089] 20 shows the third step of the manufacturing method. During the furnace brazing, the latch 43 made of brazing material melts and adheres to the first member 41 and the second member 42. When the assembly 40 is then cooled outside the furnace 93, the once-melted latch 43 is fixed to the first member 41 and the second member 42.

[0090] (2) Features The material of the latch 43 is represented by a number in the 4000 series of the ISO aluminum alloy standard. As mentioned above, aluminum alloys represented by numbers in the 1000 series, 3000 series, and 4000 series have a lower manganese content than aluminum alloys in the 2000 series and 5000 series. Therefore, by using an aluminum alloy in the 4000 series, the wettability of the latch 43 can be improved.

[0091] Furthermore, the 4000 series aluminum alloy that constitutes the latch 43 is a brazing material, and therefore the galvanic current that occurs at the contact points between the members is negligibly small, making corrosion unlikely to occur.

[0092] (3) Modifications Modifications of the first embodiment may be applied to this embodiment.

[0093] <Conclusion> Although the embodiments of the present disclosure have been described above, it will be understood that various changes in form and details can be made without departing from the spirit and scope of the present disclosure as defined in the claims.

[0094] DESCRIPTION OF SYMBOLS 10: Heat source unit 13: Heat source heat exchanger (heat exchanger) 20: Utilization unit 23: Utilization heat exchanger 40: Assembly 41: First member 41a: First hole 42: Second member 42a: Second hole 43: Latch 43a: Sawtooth shape 44: Brazing material 51: First header (stacked header) 52: Second header (stacked header) 53: Heat exchange section 54: Refrigerant pipe 55: Fin 56: Cover 56a: Latch 57: Outer wall member 58: Plate 59: Crimping claw 61: Gas side pipe 62: Sleeve 63: Bracket 64: Latch 71: Liquid side pipe 72: Pipe holding plate 73: Latch 81: Folded pipe 82: Tube holding plate 83: Latch 84: Tube holding plate 92: Conveyor 93: Furnace 100: Refrigeration device V1: First potential difference V2: Second potential difference

[0095] Japanese Patent Application Laid-Open No. 2021-025718

Claims

1. A heat exchanger (13) comprising: a first aluminum member (41) having a first hole (41a); a second aluminum member (42) having a second hole (42a); and a latch (43) disposed in the first hole and the second hole, fixed to the first member and the second member, and made of an aluminum alloy having a manganese content of 1.5% or less and a copper content of 1.0% or less.

2. The heat exchanger according to claim 1, further comprising a stacked header (51, 52), wherein at least one of the first member and the second member is a stacking plate (58) included in the stacked header.

3. A heat exchanger as claimed in claim 1 or 2, wherein the second hole is a screw hole, and the surface of the latch has a sawtooth shape (43a) that engages with the screw hole.

4. A heat exchanger as claimed in any one of claims 1 to 3, wherein a first potential difference (V1) generated by the latch and the first member coming into contact with each other, and a second potential difference (V2) generated by the latch and the second member coming into contact with each other are both 100 mV or less.

5. A heat exchanger according to any one of claims 1 to 4, wherein the material of the latch is represented by a number in the 3000 or 4000 series of the ISO aluminum alloy standard.

6. The heat exchanger according to claim 5, wherein the aluminum alloy is represented by a number in the 3000 series of ISO aluminum alloy standards, and the latch is brazed to both the first member and the second member.

7. The heat exchanger according to claim 5, wherein the aluminum alloy is represented by a number in the 4000 series of the ISO aluminum alloy standard.

8. A refrigeration system (100) comprising a heat exchanger (13) according to any one of claims 1 to 7.

9. A method for manufacturing a heat exchanger (13), comprising: preparing a first aluminum member (41) having a first hole (41a) and a second aluminum member (42) having a second hole (42a); preparing a latch (43) made of an aluminum alloy having a manganese content of 1.5% or less and a copper content of 1.0% or less; creating an assembly (40) by placing the latch in the first hole and the second hole; and heating the assembly in a furnace (93) to fix the latch to the first member and the second member.

10. The method of claim 9, wherein the second hole is a threaded hole and the latch is a bolt.

11. The manufacturing method according to claim 10, wherein the bolt is tightened with a tightening torque of 0.3 N·m or less.

12. A method according to any one of claims 9 to 11, further comprising placing the assembly on a conveyor (92) before heating the assembly in the furnace.

13. A method according to any one of claims 9 to 12, wherein the material of the latch is represented by an aluminium alloy in the 3000 range of the ISO standard, and a brazing material (44) is applied to the assembly before heating the assembly in a furnace.

14. The method of any one of claims 9 to 12, wherein the material of the latch is represented by an aluminum alloy number in the 4000 range of ISO standards, and the latch melts when the assembly is heated in a furnace.

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