JP2015114082A - Refrigerant pipeline connection body and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a refrigerant pipeline connection body capable of preventing fusion of a base material in brazing work to suppress strength deterioration without requiring a high brazing technology, and provide a refrigerant pipeline connection method.SOLUTION: A heat exchanger side gas refrigerant pipeline 31 comprising aluminum or aluminum alloy and a gas side connection refrigerant pipeline 32 comprising aluminum or aluminum alloy are connected through a gas side aluminum connection part 33 configured by fusing a brazing material containing aluminum nanoparticles.

Description

  The present invention relates to a refrigerant piping assembly and a method for manufacturing a refrigerant piping assembly.

  Conventionally, for example, when joining another refrigerant pipe to a refrigerant pipe extending from a heat exchanger of an air conditioner, a brazing material using a brazing material having a melting point lower than that of each refrigerant pipe serving as a base is used. Work is being done.

  For example, Patent Document 1 (Japanese Patent Laid-Open No. 2013-130345) describes that an aluminum alloy refrigerant pipe is brazed to an aluminum alloy heat exchanger.

  In order to braze the aluminum alloy refrigerant pipe disclosed in Patent Document 1 as described above, it is common to use an Al—Si based brazing material as the brazing material. However, the melting point of aluminum or aluminum alloy, which is the base material of the refrigerant pipe, is about 650 ° C., whereas the melting point of the brazing material of Al—Si alloy is 570 ° C. to 590 ° C., and the difference in melting point is small. . For this reason, when performing brazing by hand rather than brazing in a furnace under temperature control, etc., brazing should be performed so that the base material does not become too hot in order to prevent melting of the base material and suppress strength reduction. It is required to do. For this reason, hand brazing becomes difficult unless the worker has a skilled temperature management technique.

  Also, for example, when brazing a refrigerant pipe made of copper, a large temperature difference of about 300 ° C. is ensured between the melting point of the brazing material used for brazing the copper and the melting point of the base material. Moreover, it is possible to pour the brazing material after visually confirming that the copper of the base material has turned red during heating, and it is easy to grasp the timing of introducing the brazing material even if it is not a skilled worker. On the other hand, the base material made of aluminum or aluminum alloy not only has a small melting point difference between the brazing material and the base material, but also does not cause a change that can be visually confirmed such as reddening during heating. Melting and strength reduction are likely to occur.

  In addition, as brazing material and brazing technology, there are brazing material and brazing technology for electrical connection of electrical components of semiconductors. In such a semiconductor field, there is a demand for refrigerant piping through which a pressure fluid flows. Since strength, pressure resistance and airtightness are not required, the brazing material and brazing technique cannot be applied to the joining of refrigerant pipes as they are.

  In addition, by performing high-frequency brazing using a conventional brazing material, it is possible to suppress the temperature rise to a small level by precise temperature control. Since it tends to become, the strength reduction by heat input is inevitable.

  The present invention has been made in view of the above points, and an object of the present invention is to prevent melting of the base material during brazing operation and suppress a decrease in strength without requiring a high level of brazing technology. An object of the present invention is to provide a refrigerant pipe joined body and a refrigerant pipe joining method.

  The refrigerant pipe assembly according to the first aspect includes a first refrigerant pipe, a second refrigerant pipe, and a joint. The first refrigerant pipe is made of aluminum or an aluminum alloy. The second refrigerant pipe has at least one of aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, and stainless steel. The joining portion joins the first refrigerant pipe and the second refrigerant pipe by fusing a brazing material containing aluminano particles.

  In this refrigerant pipe joined body, the second refrigerant pipe and the first refrigerant pipe made of aluminum or an aluminum alloy are joined using aluminano particles. Here, the melting point of the aluminano particles is sufficiently lower than the melting point of the first refrigerant pipe made of aluminum or aluminum alloy because the specific surface area is increased by making the particles fine. For this reason, even when joining by hand brazing, the heating temperature is adjusted so that it does not exceed the melting point of the first refrigerant pipe made of aluminum or aluminum alloy while exceeding the melting point of the alumina particles. Easy to do.

  As a result, it is possible to prevent the base material from melting during the brazing operation and suppress the strength reduction without requiring a high level of brazing technology.

  The refrigerant piping assembly according to the second aspect is the refrigerant piping assembly according to the first aspect, and the melting point of the aluminano particles is 100 degrees or more lower than the melting point of the first refrigerant piping.

  With this refrigerant pipe assembly, temperature management during hand brazing becomes easier.

  The refrigerant pipe assembly according to the third aspect is the refrigerant pipe assembly according to the first aspect or the second aspect, and the second refrigerant pipe is made of aluminum or an aluminum alloy.

  In this refrigerant pipe assembly, the melting point of the aluminano particles is sufficiently lower than the melting point of the second refrigerant pipe made of aluminum or aluminum alloy because the specific surface area is increased by being finely divided. For this reason, even when joining by hand brazing, the heating temperature is adjusted so that it does not exceed the melting point of the second refrigerant pipe made of aluminum or aluminum alloy while exceeding the melting point of the alumina particles. Easy to do. As a result, not only the first refrigerant pipe but also the second refrigerant pipe can be prevented from melting and the strength reduction can be suppressed.

  The refrigerant piping assembly according to the fourth aspect is the refrigerant piping assembly according to any of the first to third aspects, wherein the inner diameter and outer diameter of the first refrigerant piping and the second refrigerant piping are the same, The area of the joint portion between the first refrigerant pipe and the second refrigerant pipe is wider than the cross-sectional area in the cross section perpendicular to the axial direction of the first refrigerant pipe and the second refrigerant pipe. Further, it is used in an environment where the pressure of the refrigerant flowing inside may be 1.0 MPa or more.

  Since this refrigerant pipe assembly is used in an environment where the pressure of the refrigerant flowing inside may be 1.0 MPa or more, air tightness is required. In this refrigerant pipe joined body, the first refrigerant pipe and the second refrigerant pipe are joined by fusing the aluminano particles, but by making these joint areas increased in shape, airtightness is improved. It is easy to secure.

  The refrigerant piping assembly according to the fifth aspect is the refrigerant piping assembly according to any one of the first to fourth aspects, and the melting point of the aluminano particles is lower than the softening temperature of the first refrigerant piping.

  In this refrigerant pipe joined body, since it becomes possible to fuse the alumina particles at a temperature lower than the softening temperature of the first refrigerant pipe and to join the second refrigerant pipe, the melting of the first refrigerant pipe is prevented and the strength is reduced. Can be kept sufficiently small.

  The refrigerant piping assembly according to the sixth aspect is the refrigerant piping assembly according to any one of the first to fifth aspects, and the bonding portion does not contain zinc.

  With this refrigerant pipe assembly, it is possible to make it difficult for electrical corrosion to occur with the first refrigerant pipe.

  A refrigerant pipe joining method according to a seventh aspect includes a first refrigerant pipe made of aluminum or an aluminum alloy, and at least one of aluminum, an aluminum alloy, copper, a copper alloy, and stainless steel. A second refrigerant pipe that is provided, and a first refrigerant pipe and a second refrigerant pipe are fused by interposing a brazing material containing aluminano particles between the first refrigerant pipe and the second refrigerant pipe. Joining the refrigerant piping.

  In this refrigerant pipe joining method, the second refrigerant pipe and the first refrigerant pipe made of aluminum or an aluminum alloy are joined using alumino particles. Here, the melting point of the aluminano particles is sufficiently lower than the melting point of the first refrigerant pipe made of aluminum or aluminum alloy because the specific surface area is increased by making the particles fine. For this reason, even when joining by hand brazing, the heating temperature is adjusted so that it does not exceed the melting point of the first refrigerant pipe made of aluminum or aluminum alloy while exceeding the melting point of the alumina particles. Easy to do.

  As a result, it is possible to prevent the base material from melting during the brazing operation and suppress the strength reduction without requiring a high level of brazing technology.

  A refrigerant pipe joining method according to an eighth aspect is a method for producing a refrigerant pipe joined body according to the seventh aspect, wherein the first refrigerant pipe and the second refrigerant pipe have the same inner diameter and outer diameter, and the first refrigerant pipe The area of the joint portion between the first refrigerant pipe and the second refrigerant pipe is wider than the cross-sectional area in the cross section perpendicular to the axial direction of the first refrigerant pipe and the second refrigerant pipe.

  In this refrigerant pipe joining method, the first refrigerant pipe and the second refrigerant pipe are joined by fusing the aluminano particles. However, by making the shape of the joint area increased, airtightness is ensured. It becomes easy.

  A refrigerant pipe joining method according to a ninth aspect is a method for producing a refrigerant pipe joined body according to the seventh aspect or the eighth aspect, wherein a wax containing aluminano particles between the first refrigerant pipe and the second refrigerant pipe. When fusing with the material interposed, pressure is applied so that the first refrigerant pipe and the second refrigerant pipe are pressed against each other.

  In this refrigerant pipe joining method, it is possible to further improve the airtightness.

  In the refrigerant pipe assembly according to the first aspect, it is possible to prevent the base material from melting during the brazing operation and suppress the strength reduction without requiring a high level of brazing technical power.

  In the refrigerant piping assembly according to the second aspect, temperature management during hand brazing becomes easier.

  In the refrigerant pipe assembly according to the third aspect, not only the first refrigerant pipe but also the second refrigerant pipe can be prevented from melting and the strength reduction can be suppressed.

  In the refrigerant pipe assembly according to the fourth aspect, airtightness can be easily ensured by adopting a shape with an increased bonding area.

  In the refrigerant pipe assembly according to the fifth aspect, it is possible to prevent the first refrigerant pipe from being melted and to suppress a decrease in strength sufficiently small.

  In the refrigerant pipe assembly according to the sixth aspect, it is possible to make it difficult for electrical corrosion to occur with the first refrigerant pipe.

  In the method for manufacturing a refrigerant pipe assembly according to the seventh aspect, it is possible to prevent melting of the base material during brazing operation and suppress a decrease in strength without requiring a high level of brazing technology.

  In the manufacturing method of the refrigerant piping assembly according to the eighth aspect, it is easy to ensure airtightness by increasing the bonding area.

  In the manufacturing method of the refrigerant pipe assembly according to the ninth aspect, the airtightness can be further improved.

The circuit diagram for demonstrating the outline | summary of a structure of the air conditioning apparatus which concerns on one Embodiment. The perspective view which shows the external appearance of an air-conditioning outdoor unit. Typical sectional drawing for demonstrating the outline | summary of arrangement | positioning of each apparatus of an air-conditioning outdoor unit. The typical rear view which shows schematic structure of an outdoor heat exchanger. The partial expanded sectional view for demonstrating the structure of an outdoor heat exchanger. The partial expanded sectional view for demonstrating the structure of the heat exchange part of an outdoor heat exchanger. It is a figure which shows the joining aspect of heat exchanger side gas refrigerant piping and gas side connection refrigerant | coolant piping. It is a figure which shows the joining aspect of copper gas refrigerant piping and gas side connection refrigerant | coolant piping. It is a figure which shows the joining aspect which concerns on other embodiment A. It is a figure which shows the joining aspect which concerns on other Embodiment B. It is a figure which shows the joining aspect which concerns on other Embodiment C. It is a figure which shows the joining aspect which concerns on other Embodiment D. It is a figure which shows the joining aspect which concerns on other embodiment E. FIG.

  Hereinafter, an embodiment of the present invention will be specifically described by way of example, but the present invention is not limited to these descriptions.

(1) Overall Configuration of Air Conditioner FIG. 1 is a circuit diagram showing an outline of the configuration of an air conditioner having a refrigerant pipe.

  The air conditioner 1 includes an air conditioning outdoor unit 2 (heat source side unit) and an air conditioning indoor unit 3 (use side unit). The air conditioner 1 is an apparatus used for air conditioning in a building where an air conditioning indoor unit 3 is installed by performing a vapor compression refrigeration cycle operation. The air conditioner 1 includes an air conditioning outdoor unit 2 as a heat source unit, an air conditioning indoor unit 3 as a utilization unit, and refrigerant communication pipes 6 and 7 that connect the air conditioning outdoor unit 2 and the air conditioning indoor unit 3. .

  The refrigeration circuit configured by connecting the air-conditioning outdoor unit 2, the air-conditioning indoor unit 3, and the refrigerant communication pipes 6 and 7 includes a compressor 91, a four-way switching valve 92, an outdoor heat exchanger 20, an expansion valve 40, and indoor heat. The exchanger 4 and the accumulator 93 are connected by a refrigerant pipe. A refrigerant is sealed in the refrigeration circuit, and a refrigeration cycle operation is performed in which the refrigerant is compressed, cooled, decompressed, heated and evaporated, and then compressed again. As the refrigerant, for example, one selected from R410A, R407C, R22, R134a, R32, carbon dioxide, and the like is used.

  In addition, the pressure of the refrigerant | coolant in a refrigerant circuit may be 1.0 Mpa or more, and it can take the range of 3.6 Mpa or more and 63 Mpa or less as a refrigerant | coolant pressure, for example.

(2) Operation of the air conditioner (2-1) Cooling operation During the cooling operation, the four-way switching valve 92 is in the state indicated by the solid line in FIG. 1, that is, the discharge side of the compressor 91 is the gas of the outdoor heat exchanger 20. And the suction side of the compressor 91 is connected to the gas side of the indoor heat exchanger 4 via the accumulator 93, the gas refrigerant side closing valve 95 and the refrigerant communication pipe 7. The opening of the expansion valve 40 is adjusted so that the degree of superheat of the refrigerant at the outlet of the indoor heat exchanger 4 (that is, the gas side of the indoor heat exchanger 4) is constant. When the compressor 91, the outdoor fan 70 and the indoor fan 5 are operated in the state of this refrigeration circuit, the low-pressure gas refrigerant is sucked into the compressor 91 and compressed to become a high-pressure gas refrigerant. The high-pressure gas refrigerant passes through the four-way switching valve 92, the copper gas refrigerant pipe 41, the aluminum gas side connection refrigerant pipe 32, and the aluminum heat exchanger side gas refrigerant pipe 31 to the outdoor heat exchanger 20. Sent to. Thereafter, the high-pressure gas refrigerant is condensed in the outdoor heat exchanger 20 by exchanging heat with the outdoor air supplied by the outdoor fan 70 to become a high-pressure liquid refrigerant. The supercooled high-pressure liquid refrigerant passes from the outdoor heat exchanger 20 through the aluminum heat exchanger side liquid refrigerant pipe 35, the aluminum liquid side connection refrigerant pipe 36, and the copper liquid refrigerant pipe 42. Then, it is sent to the expansion valve 40. The pressure is reduced to near the suction pressure of the compressor 91 by the expansion valve 40 and is sent to the indoor heat exchanger 4 as a low-pressure gas-liquid two-phase refrigerant. The indoor heat exchanger 4 exchanges heat with the indoor air. Evaporates into a low-pressure gas refrigerant.

  The copper gas refrigerant pipe 41 and the copper liquid refrigerant pipe 42 may be made of a copper alloy, for example, a copper alloy containing copper as a main component, a copper alloy containing 95 wt% or more of copper, and 99 wt% of copper. % Or more of a copper alloy or the like may be included. An aluminum heat exchanger side gas refrigerant pipe 31, an aluminum gas side connection refrigerant pipe 32, an aluminum heat exchanger side liquid refrigerant pipe 35, and an aluminum liquid side connection refrigerant pipe 36 are made of an aluminum alloy. For example, it may be composed of an aluminum alloy containing aluminum as a main component, an aluminum alloy containing 95% by weight or more of aluminum, an aluminum alloy containing 99% by weight or more of aluminum, and the like.

  This low-pressure gas refrigerant is sent to the air-conditioning outdoor unit 2 via the refrigerant communication pipe 7, and again sucked into the compressor 91 via the gas refrigerant-side closing valve 95 and the four-way switching valve 92. As described above, in the cooling operation, the air conditioner 1 uses the outdoor heat exchanger 20 as the refrigerant condenser compressed in the compressor 91 and the indoor heat exchanger 4 as the refrigerant condensed in the outdoor heat exchanger 20. To function as an evaporator.

(2-2) Heating Operation During the heating operation, the four-way switching valve 92 is in the state indicated by the broken line in FIG. 1, that is, the discharge side of the compressor 91 is indoors via the gas refrigerant side closing valve 95 and the refrigerant communication pipe 7. It is connected to the gas side of the heat exchanger 4 and the suction side of the compressor 91 is connected to the gas side of the outdoor heat exchanger 20. Further, the liquid refrigerant side closing valve 94 and the gas refrigerant side closing valve 95 are opened. The opening of the expansion valve 40 is adjusted so that the degree of supercooling of the refrigerant at the outlet of the indoor heat exchanger 4 becomes constant at the target value of the degree of supercooling. When the compressor 91, the outdoor fan 70, and the indoor fan 5 are operated in the state of this refrigeration circuit, the low-pressure gas refrigerant is sucked into the compressor 91 and compressed to become a high-pressure gas refrigerant, and the four-way switching valve 92, The gas is sent to the air conditioning indoor unit 3 via the gas refrigerant side closing valve 95 and the refrigerant communication pipe 7.

  Then, the high-pressure gas refrigerant sent to the air conditioning indoor unit 3 undergoes heat exchange with room air in the indoor heat exchanger 4 to condense into a high-pressure liquid refrigerant, and then passes through the expansion valve 40. Further, the pressure is reduced according to the opening degree of the expansion valve 40. The refrigerant that has passed through the expansion valve 40 flows into the outdoor heat exchanger 20 via a copper liquid refrigerant pipe 42, an aluminum liquid side connection refrigerant pipe 36, and a heat exchanger side liquid refrigerant pipe 35. Then, the low-pressure gas-liquid two-phase refrigerant flowing into the outdoor heat exchanger 20 exchanges heat with outdoor air supplied by the outdoor fan 70 to evaporate into a low-pressure gas refrigerant, thereby exchanging aluminum heat. The air is again sucked into the compressor 91 via the gas gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32, the copper gas refrigerant pipe 41 and the four-way switching valve 92. As described above, in the heating operation, the air conditioner 1 uses the indoor heat exchanger 4 as a refrigerant condenser compressed in the compressor 91 and the outdoor heat exchanger 20 as a refrigerant condensed in the indoor heat exchanger 4. To function as an evaporator.

(3) Detailed configuration of air conditioner (3-1) Air-conditioning indoor unit The air-conditioning indoor unit 3 is installed on the wall surface of the room by wall hanging or the like, or embedded or suspended in the ceiling of a room such as a building. The air conditioning indoor unit 3 has an indoor heat exchanger 4 and an indoor fan 5. The indoor heat exchanger 4 is, for example, a cross fin type fin-and-tube heat exchanger composed of heat transfer tubes and a large number of fins, and functions as a refrigerant evaporator during cooling operation to cool indoor air. In the heating operation, the heat exchanger functions as a refrigerant condenser and heats indoor air.

(3-2) Air Conditioning Outdoor Unit The air conditioning outdoor unit 2 is installed outside a building or the like, and is connected to the air conditioning indoor unit 3 via the refrigerant communication pipes 6 and 7. As shown in FIGS. 2 and 3, the air conditioning outdoor unit 2 includes a unit casing 10 having a substantially rectangular parallelepiped shape. As shown in FIG. 3, the air conditioner outdoor unit 2 has a structure in which the blower chamber S <b> 1 and the machine chamber S <b> 2 are formed by dividing the internal space of the unit casing 10 into two by a partition plate 18 extending in the vertical direction. (So-called trunk type structure).

  The unit casing 10 includes a bottom plate 12, a top plate 11, a blower chamber side plate 13, a machine chamber side plate 14, a blower chamber side front plate 15, and a machine chamber side front plate 16. . The top plate 11 is a plate-like member that constitutes the top surface portion of the unit casing 10. The bottom plate 12 is a plate-like member that constitutes the bottom portion of the unit casing 10. Below the bottom plate 12, two foundation legs 19 are provided that are fixed to the field installation surface. The blower chamber side plate 13 is a plate-like member that constitutes a side surface portion of the unit casing 10 near the blower chamber S1. The machine room side plate 14 is a plate-like member that constitutes a part of a side surface portion of the unit casing 10 near the machine room S2 and a back surface portion of the unit casing 10 near the machine room S2. The blower chamber side front plate 15 is a plate-like member that constitutes the front portion of the blower chamber S1 of the unit casing 10 and a part of the front portion of the machine chamber S2 of the unit casing 10.

  The air conditioner outdoor unit 2 is configured to suck outdoor air into the blower chamber S <b> 1 in the unit casing 10 from a part of the back surface and side surface of the unit casing 10, and blow out the sucked outdoor air from the front surface of the unit casing 10. . Therefore, the outdoor air suction port 10a sucked into the blower chamber S1 in the unit casing 10 is between the end portion on the back side of the blower chamber side plate 13 and the end portion on the blower chamber S1 side of the machine chamber side plate 14. The outdoor air suction port 10 b is formed in the blower chamber side plate 13. Further, a blower chamber side front plate 15 is provided with an outlet 10c for blowing the outdoor air sucked into the blower chamber S1 to the outside. The front side of the air outlet 10c is covered with a fan grill 15a.

  The compressor 91 is a hermetic compressor driven by a compressor motor, for example, and is configured to be able to vary the operation capacity. The compressor 91 is disposed in the machine room S2.

  The four-way switching valve 92 is a mechanism for switching the direction of refrigerant flow. During the cooling operation, the four-way switching valve 92 connects the refrigerant pipe on the discharge side of the compressor 91 and one end of the outdoor heat exchanger 20, and connects the gas refrigerant side shut-off valve 95 and the compressor 91 via the accumulator 93. The refrigerant pipe on the suction side is connected (see the solid line of the four-way switching valve 92 in FIG. 1). During the heating operation, the four-way switching valve 92 connects the discharge-side refrigerant pipe of the compressor 91 and the gas refrigerant-side shut-off valve 95, and exchanges outdoor heat with the compressor suction-side pipe 29a via the accumulator 93. One end of the container 20 is connected (see the broken line of the four-way switching valve 92 in FIG. 1).

  The outdoor heat exchanger 20 is disposed upright in the blower chamber S1 in the vertical direction (vertical direction) and faces the suction ports 10a and 10b. The outdoor heat exchanger 20 is an aluminum heat exchanger. In order to prevent corrosion, the aluminum outdoor heat exchanger 20 is attached to the unit casing 10 so as not to directly contact the steel plate top plate 11, the bottom plate 12, the blower chamber side plate 13, the machine chamber side plate 14, and the like. It has been. One end of the outdoor heat exchanger 20 is connected to the four-way switching valve 92, and the other end is connected to the expansion valve 40.

  The accumulator 93 is disposed in the machine room S <b> 2 and is connected between the four-way switching valve 92 and the compressor 91. The accumulator 93 has a gas-liquid separation function that divides the refrigerant into a gas phase and a liquid phase. The refrigerant flowing into the accumulator 93 is divided into a liquid phase and a gas phase, and the gas phase refrigerant that collects in the upper space is supplied to the compressor 91.

  The air-conditioning outdoor unit 2 has an outdoor fan 70 for sucking outdoor air into the unit and discharging it outside the unit again. The outdoor fan 70 exchanges heat between the outdoor air and the refrigerant flowing through the outdoor heat exchanger 20. The expansion valve 40 is a mechanism for decompressing the refrigerant in the refrigeration circuit, and is an electric valve capable of adjusting the opening degree. The expansion valve 40 is provided in the gas refrigerant pipe 41 between the outdoor heat exchanger 20 and the liquid refrigerant side shut-off valve 94 in order to adjust the refrigerant pressure and the refrigerant flow rate, and in any of the cooling operation and the heating operation. Has a function of expanding the refrigerant.

  The outdoor fan 70 is disposed in the blower chamber S1 so as to face the outdoor heat exchanger 20. The outdoor fan 70 sucks outdoor air into the unit, causes the outdoor heat exchanger 20 to perform heat exchange between the refrigerant and the outdoor air, and then discharges the air after heat exchange to the outside. The outdoor fan 70 is a fan capable of changing the air volume of air supplied to the outdoor heat exchanger 20, and is, for example, a propeller fan driven by a motor such as a DC fan motor.

(3-2-1) Outdoor Heat Exchanger Next, the configuration of the outdoor heat exchanger 20 and piping connected to the outdoor heat exchanger 20 will be described in detail with reference to FIGS. 4 and 5.

  The outdoor heat exchanger 20 includes a heat exchanging portion 21 that exchanges heat between the outdoor air and the refrigerant. The heat exchanging portion 21 includes a large number of aluminum heat transfer fins 21a and a large number of flat aluminum plates. It consists of a hole tube 21b. The flat multi-hole tube 21b functions as a heat transfer tube, and transfers heat moving between the heat transfer fins 21a and outdoor air to the refrigerant flowing inside.

  The outdoor heat exchanger 20 includes aluminum header collecting pipes 22 and 23, one on each end of the heat exchange unit 21. The header collecting pipe 22 has internal spaces 22a and 22b separated from each other by a baffle 22c. An aluminum heat exchanger side gas refrigerant pipe 31 is connected to the upper internal space 22a, and an aluminum heat exchanger side liquid refrigerant pipe 35 is connected to the lower internal space 22b.

  The header collecting pipe 23 is partitioned by baffles 23f, 23g, 23h, and 23i to form internal spaces 23a, 23b, 23c, 23d, and 23e. A number of flat multi-hole tubes 21 b connected to the internal space 22 a above the header collecting pipe 22 are connected to the three internal spaces 23 a, 23 b, 23 c of the header collecting pipe 23. A large number of flat multi-hole tubes 21 b connected to the inner space 22 b below the header collecting tube 22 are connected to the three inner spaces 23 c, 23 d, and 23 e of the header collecting tube 23.

  Further, the internal space 23 a and the internal space 23 e of the header collecting pipe 23 are connected by a connecting pipe 24, and the internal space 23 b and the internal space 23 d are connected by a connecting pipe 25. The internal space 23c also functions to connect a part of the upper part (part connected to the internal space 22a) and a part of the lower part (part connected to the internal space 22b) of the heat exchanging part 21. With these configurations, for example, during cooling operation, the gas refrigerant supplied to the internal space 23 a above the header collecting pipe 23 by the aluminum heat exchanger-side gas refrigerant pipe 31 performs heat exchange at the top of the heat exchanging section 21. The liquid is liquefied, turned back at the header collecting pipe 23, passes through the lower part of the heat exchanging portion 21, and exits from the heat exchanger side liquid refrigerant pipe 35 made of aluminum.

  As already described, since the outdoor heat exchanger 20 using aluminum or aluminum alloy is an aluminum heat exchanger, the heat transfer fins 21a made of aluminum, the flat multi-hole tube 21b made of aluminum, and the product made of aluminum are used. The main material constituting the header collecting pipes 22 and 23 is aluminum or an aluminum alloy.

(3-2-2) Heat Exchange Part FIG. 6 is a partially enlarged view showing a cross-sectional structure in a plane perpendicular to the flat multi-hole tube 21b of the heat exchange part 21 of the outdoor heat exchanger 20.

  The heat transfer fins 21a are thin aluminum flat plates, and a plurality of cutouts 21aa extending in the horizontal direction are formed in each heat transfer fin 21a in the vertical direction. The flat multi-hole tube 21b has upper and lower flat portions serving as heat transfer surfaces and a plurality of internal flow paths 21ba through which the refrigerant flows. The flat multi-hole tubes 21b that are slightly thicker than the upper and lower widths of the cutouts 21aa are arranged in a plurality of stages at intervals with the plane portion facing up and down, and are temporarily fixed in a state of being fitted into the cutouts 21aa. The Thus, the heat transfer fin 21a and the flat multi-hole tube 21b are brazed in a state where the flat multi-hole tube 21b is fitted in the notch 21aa of the heat transfer fin 21a. Further, both ends of each flat multi-hole tube 21b are fitted into the header collecting tubes 22 and 23 and brazed. Therefore, the internal spaces 22a and 22b of the header collecting pipe 22 and the internal spaces 23a, 23b, 23c, 23d and 23e of the header collecting pipe 23 and the internal flow path 21ba of the flat multi-hole pipe 21b are connected. The heat exchanger side gas refrigerant pipe 31 and the heat exchanger side liquid refrigerant pipe 35 are brazed to the header collecting pipe 22.

  Here, the heat transfer fin 21a, the flat multi-hole pipe 21b, the header collecting pipes 22 and 23, the connection pipes 24 and 25, the heat exchanger side gas refrigerant pipe 31 and the heat exchanger side liquid refrigerant pipe 35 are the members. In a state where the brazing material is applied to the joint portion, the brazing material is brazed by being placed in a temperature-controlled furnace.

  As shown in FIG. 6, since the heat transfer fins 21 a are connected to each other in the vertical direction, the condensation generated in the heat transfer fins 21 a and the flat multi-hole tube 21 b drops down along the heat transfer fins 21 a. The liquid is discharged to the outside through a path formed in the bottom plate 12. With such a structure, the header collecting pipes 22, 23, the heat exchanger side gas refrigerant pipe 31, the gas side connection refrigerant pipe 32, the heat exchanger side liquid refrigerant pipe 35, and the liquid side connection refrigerant pipe 36 are connected from the heat exchanging portion 21. The water droplets generated in the heat exchanging portion 21 are prevented from being transmitted to the copper gas refrigerant pipe 41 and the liquid refrigerant pipe 42 through the heat exchanger 21.

(3-2-3) Refrigerant piping around the outdoor heat exchanger As shown in FIG. 4, the end of the aluminum heat exchanger side gas refrigerant piping 31 opposite to the outdoor heat exchanger 20 side. The portion extends upward, and is connected to the gas side connection refrigerant pipe 32 made of aluminum via the gas side aluminum connection portion 33 so as to guide the refrigerant to a desired position inside the unit casing 10. . The gas-side connecting refrigerant pipe 32 made of aluminum extends upward and then folds back and extends downward, and the end facing the lower side opposite to the gas-side aluminum connecting portion 33 side is connected to the gas-side copper connecting portion 34. The gas refrigerant pipe 41 made of copper is connected to the copper gas refrigerant pipe 41. These aluminum heat exchanger side gas refrigerant pipes 31, aluminum gas side connection refrigerant pipes 32, gas side aluminum connection parts 33, gas side copper connection parts 34, and copper gas refrigerant pipes 41 are gas refrigerants. A pipe assembly 30A is configured.

  Further, the end of the aluminum heat exchanger side liquid refrigerant pipe 35 opposite to the outdoor heat exchanger 20 side extends upward, and guides the refrigerant to a desired position inside the unit casing 10. In addition, the liquid side connection refrigerant pipe 36 made of aluminum is connected through the liquid side aluminum connection part 37. The liquid side connection refrigerant pipe 36 made of aluminum extends upward and then folds back and extends downward, and the end facing the lower side opposite to the liquid side aluminum connection part 37 side is the liquid side copper connection part. The liquid refrigerant pipe 42 made of copper is connected to the copper through the pipe 38. The heat exchanger side liquid refrigerant pipe 35 made of aluminum, the liquid side connection refrigerant pipe 36 made of aluminum, the liquid side aluminum connection part 37, the liquid side copper connection part 38, and the liquid refrigerant pipe 42 made of copper are joined by a liquid refrigerant pipe. The body 30B is configured.

  Here, the gas side aluminum connection part 33, the gas side copper connection part 34, the liquid side aluminum connection part 37, and the liquid side copper connection part 38 are all configured by a fusion product of aluminano particles.

(4) Manufacturing method of gas refrigerant pipe assembly and liquid refrigerant pipe assembly As described above, heat transfer fins 21a, flat multi-hole pipes 21b, header collecting pipes 22, 23, connection pipes 24, 25, heat exchanger side The gas refrigerant pipe 31 and the heat exchanger side liquid refrigerant pipe 35 are brazed and integrated by being placed in a temperature-controlled furnace.

  An aluminum gas-side connecting refrigerant pipe 32 is connected to the integrated heat exchanger-side gas refrigerant pipe 31 by hand brazing, and a copper gas refrigerant pipe 41 is further connected by high-frequency brazing. The Similarly, the liquid-side connection refrigerant pipe 36 made of aluminum is connected to the heat exchanger-side liquid refrigerant pipe 35 of the integrated product by hand brazing, and the copper liquid refrigerant pipe 42 is further connected by high-frequency brazing. Connected.

  As shown in FIG. 7, the end of the heat exchanger side gas refrigerant pipe 31 opposite to the outdoor heat exchanger 20 side is partially expanded, and aluminum is formed inside the expanded portion. One end side of the gas side connection refrigerant pipe 32 is inserted. The outer diameter and inner diameter of the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 are equal, and the inner diameter of the expanded portion of the heat exchanger side gas refrigerant pipe 31 is larger than the outer diameter of the gas side connection refrigerant pipe 32. It has also been made slightly wider. Here, alumino particles are applied to the outer peripheral surface at the tip of the gas side connection refrigerant pipe 32 and inserted inside the expanded portion of the heat exchanger side gas refrigerant pipe 31, and hand brazed (around the joint with a burner) The heat exchanger side gas refrigerant piping is performed by fusing alumino particles having a melting point lower than that of the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32. 31 and the gas side connection refrigerant | coolant piping 32 are joined via the gas side aluminum connection part 33. FIG. In addition, in order to ensure sufficient joining area and improve airtightness, the area of the junction part of the heat exchanger side gas refrigerant piping 31 and the gas side connection refrigerant piping 32 is the heat exchanger side gas refrigerant piping 31 and gas side connection. The refrigerant pipe 32 is adjusted to be wider than a cross-sectional area in a cross section perpendicular to the axial direction. Here, the brazing temperature of the hand brazing is a temperature that exceeds the melting point of the aluminano particles and does not exceed the melting points of the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 that are the base materials. It is preferable that the temperature does not exceed the softening temperature of the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 that are the base materials.

  Moreover, as shown in FIG. 8, the end part of the one end side of the copper gas refrigerant pipe 41 is partially expanded, and the heat exchanger side gas in the gas side connection refrigerant pipe 32 is inside the expanded pipe part. The end opposite to the refrigerant pipe 31 side is inserted. The outer diameter and inner diameter of the copper gas refrigerant pipe 41 and the gas side connecting refrigerant pipe 32 are equal, and the inner diameter of the expanded portion of the copper gas refrigerant pipe 41 is slightly wider than the outer diameter of the gas side connecting refrigerant pipe 32. It is supposed to be. Here, alumino particles are applied to the outer peripheral surface at the tip of the gas side connection refrigerant pipe 32 and inserted inside the expanded portion of the copper gas refrigerant pipe 41, and then high frequency brazing (melting of the alumina particles by high frequency induction heating) is performed. The copper gas refrigerant pipe 41 and the gas side connection refrigerant pipe 32 are connected to the gas side copper by fusing alumino particles having a melting point lower than that of the copper gas refrigerant pipe 41 and the gas side connection refrigerant pipe 32. It joins via the connection part 34. FIG. In order to secure a sufficient bonding area and improve airtightness, the area of the bonding portion between the copper gas refrigerant pipe 41 and the gas side connection refrigerant pipe 32 is the same as that of the copper gas refrigerant pipe 41 and the gas side connection refrigerant pipe 32. The cross-sectional area in the cross section perpendicular to the axial direction is adjusted to be wider. Here, the brazing temperature of the high-frequency brazing is a temperature that exceeds the melting point of the aluminano particles and that does not exceed the melting point of the copper gas refrigerant pipe 41 and the gas-side connecting refrigerant pipe 32 that are the base materials. Preferably, it is more preferable that the temperature does not exceed the softening temperature of the copper gas refrigerant pipe 41 and the gas side connection refrigerant pipe 32 that are the base materials.

  In the above description, heating is described so as to exceed the melting point of the alumina particles. However, in a state where the bonding is finished, the gas side aluminum connection portion 33, the gas side copper connection portion 34, and the liquid side aluminum connection portion 37 are slightly used. In the liquid side copper connection part 38, the alumina particles may remain in the nano size.

  Further, the heat exchanger side liquid refrigerant pipe 35 and the liquid side connection refrigerant pipe 36 are joined through a liquid side aluminum connection part 37 in which the alumina particles are fused, and the liquid side connection refrigerant pipe 36 and the copper liquid refrigerant. The point where the pipe 42 is joined via the liquid side copper connection part 38 to which the alumina particles are fused is that the heat exchanger side gas refrigerant pipe 31, the gas side connection refrigerant pipe 32, and the copper gas refrigerant pipe 41 are connected. Since it is the same, description is abbreviate | omitted.

(5) Aluminum or aluminum alloy constituting the heat exchanger side gas refrigerant pipe 31, the gas side connection refrigerant pipe 32, the heat exchanger side liquid refrigerant pipe 35, the liquid side connection refrigerant pipe 36, the heat exchanger side gas refrigerant pipe 31, The aluminum or aluminum alloy constituting the gas side connection refrigerant pipe 32, the heat exchanger side liquid refrigerant pipe 35, and the liquid side connection refrigerant pipe 36, that is, the base material is not particularly limited, but has a melting point of 600 ° C. or higher and 700 ° C. or lower. It is preferably 630 ° C. or more and 670 ° C. or less, and particularly preferably 640 ° C. or more and 660 ° C. or less.

  The melting point of these base materials is a value obtained by measurement by a suggested thermal analysis method.

  Further, the softening temperature of these base materials is preferably 200 ° C. or higher and 300 ° C. or lower, and more preferably 250 ° C. or higher and 270 ° C. or lower.

  The softening temperature of these base materials is the softening start point in the isochronous softening curve of tensile strength.

(6) Aluminano particles The alumino particles are particles having an average particle diameter of 500 nm or less as observed in a transmission electron micrograph. Here, the average particle diameter means a value obtained by randomly extracting 100 particles observed in a transmission electron micrograph and taking the average. The particle shape is not particularly limited, and may be spherical, rod-like, or string-like.

  Here, the upper limit of the average particle diameter of the alumina particles may be 500 nm or less, 100 nm or less, or 50 nm or less. The lower limit of the average particle diameter of the aluminano particles is not particularly limited, but may be, for example, 1 nm or more, or 10 nm or more.

  The composition of the alumina particles is not particularly limited, and may be composed of pure aluminum, aluminum oxide, aluminum alloy, or the like. From the viewpoint of suppressing electrical corrosion, it is preferable that the aluminano particles do not contain a different metal such as zinc. From the viewpoint of environmental burden, it is preferable that the aluminano particles do not contain lead.

  The aluminano particles preferably constitute 50% by weight or more of the brazing material at the time of application, and more preferably constitute 90% by weight or more. Although not particularly limited, the aluminano particles at the time of coating may be dispersed in an alcohol solvent such as ethanol or terpineol (terpineol) as a dispersion medium. These dispersion media are preferably those that do not easily remain after the aluminano particles are fused from the viewpoint of increasing the strength.

  Moreover, in the gas side aluminum connection part 33, the gas side copper connection part 34, the liquid side aluminum connection part 37, and the liquid side copper connection part 38 after the fusion of the alumina particles, the ratio of aluminum or aluminum alloy is 90% by weight. It is preferable that the amount be 95% by weight or more.

  The state of the alumina particles is not particularly limited, and may be a powder or a state dispersed in a dispersion medium.

  The method for producing the aluminano particles is not particularly limited, and can be obtained, for example, by an electric explosion method in which high-voltage pulses are applied to cause evaporation. Aluminano particles may be obtained as a commercial product. Examples of commercially available products include Nippon Ion Co., Ltd.

  The melting point of the alumina particles is a value obtained by a method of directly melting under an electron microscope.

  The aluminano particles have a melting point in a dry state of preferably 450 ° C. or lower, more preferably 300 ° C. or lower, and particularly preferably 200 ° C. or lower.

  The melting point of the alumina particles is preferably 100 degrees or more lower than the melting point of the base material described above, more preferably 150 degrees or more, and particularly preferably 200 degrees or more.

  Furthermore, the melting point of the alumina particles is preferably lower than the softening temperature of the base material described above, more preferably 50 degrees or more lower than the softening temperature of the base material described above, and 100 degrees or higher than the softening temperature of the base material described above. More preferably, it is low.

(7) Features Although it is possible to perform low-temperature bonding of each refrigerant pipe by performing friction stir welding using a conventional brazing material, there is a possibility that securing airtightness may be insufficient. Further, in the bonding using an adhesive, it is difficult to ensure the bonding strength of the refrigerant pipe, particularly at high temperatures, and it may be difficult to ensure airtightness.

  On the other hand, in the gas refrigerant pipe assembly 30A of the present embodiment, the heat exchanger side gas refrigerant pipe 31 made of aluminum and the aluminum product are made by interposing the gas side aluminum connecting part 33 in which the alumina particles are fused. The gas side connection refrigerant pipe 32 is joined. Further, in the liquid refrigerant pipe assembly 30B, an aluminum heat exchanger side liquid refrigerant pipe 35 and an aluminum liquid side connection refrigerant pipe 36 are provided by interposing a liquid side aluminum connection part 37 in which alumina nanoparticles are fused. Are joined.

  In this way, it is possible to lower the bonding temperature by using a nano-sized brazing material having a very small specific surface area such as alumino particles. By reducing the bonding temperature in this way, the strength of the base material of the heat exchanger side gas refrigerant pipe 31, the gas side connection refrigerant pipe 32, the heat exchanger side liquid refrigerant pipe 35, and the liquid side connection refrigerant pipe 36 is reduced. It is possible to keep it small. Moreover, since the alumina particles are sufficiently fused at a low temperature, it is possible to ensure airtightness.

  Moreover, in the gas side aluminum connection part 33 and the liquid side aluminum connection part 37 of the said embodiment, it is made not to contain zinc which is generally contained in the low-temperature brazing material, so that electrical corrosion between metals is performed. Can be suppressed.

(8) Other Embodiments In the above embodiment, an example of the embodiment of the present invention has been described. However, the above embodiment is not intended to limit the present invention, and is not limited to the above embodiment. The present invention naturally includes aspects appropriately modified without departing from the spirit of the present invention.

(8-1) Other embodiment A
In the said embodiment, as shown in FIG.7, FIG.8, it demonstrated taking the example of the form joined as it expanded one pipe | tube and inserted the other.

  However, the present invention is not limited to this. For example, as shown in FIG. 9, the cross section perpendicular to the axial direction of the heat exchanger side gas refrigerant pipe 31 and the axial direction of the gas side connection refrigerant pipe 32 are provided. A simple cross section may be joined via the gas side aluminum connecting portion 33. In this case, the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 are pressed so as to be close to each other in the axial direction (see the arrow in FIG. 9), so that the aluminano particles are densely bonded. It becomes possible to improve the airtightness further.

(8-2) Other embodiment B
In addition, as a joining form, for example, as shown in FIG. 10, an inclined cross section formed on the outside so as to taper toward the end in the axial direction of the heat exchanger side gas refrigerant pipe 31, and the gas side You may make it join via the gas side aluminum connection part 33 with the inclined cross section formed inside so that it may spread as it goes to the edge part of the connection refrigerant | coolant piping 32 in the axial direction. Also in this case, the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 are pressed so as to be close to each other in the axial direction (see the arrow in FIG. 10), so that the aluminano particles are densely fused. It becomes possible to improve the airtightness further.

  In addition, in this joining form, if the joining area of the heat exchanger side gas refrigerant piping 31 and the gas side connection refrigerant piping 32 can fully be ensured, you may have a mutually different diameter relationship.

(8-3) Other embodiment C
In addition, as a joining form, for example, as shown in FIG. 11, the end portion of the heat exchanger side gas refrigerant pipe 31 has a joining portion extending vertically in the axial direction, and the gas side connecting refrigerant pipe The end portion of 32 may also have a joining portion extending perpendicularly in the axial direction, and each joining portion may be joined via the gas side aluminum connection portion 33. Also in this case, the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 are pressed so as to be close to each other in the axial direction (see the arrow in FIG. 11), so that the aluminano particles are dense and the fused state is obtained. It becomes possible to improve the airtightness further.

  Even in this bonding mode, the diameters of the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 may be different from each other as long as a sufficient bonding area can be secured.

(8-4) Other embodiment D
In addition, as a joining form, for example, as shown in FIG. 12, it has a joining portion configured such that the inner diameter and the outer diameter become smaller toward the end of the heat exchanger side gas refrigerant pipe 31. And has a joining portion configured such that the inner diameter and the outer diameter become larger toward the end of the gas-side connecting refrigerant pipe 32, and each joining portion of the refrigerant pipe having a different inner diameter and outer diameter is a gas. You may make it join via the side aluminum connection part 33. FIG. Also in this case, the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 are pressed so as to be close to each other in the axial direction (see the arrow in FIG. 12), so that the aluminano particles are densely bonded. It becomes possible to improve the airtightness further.

(8-5) Other embodiment E
In addition, as a joining form, for example, as shown in FIG. 13, a heat exchanger side gas refrigerant pipe 31 of another embodiment D and a gas side connection refrigerant pipe 32 of another embodiment B are combined. May be joined. Also in this case, the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 are pressed so as to be close to each other in the axial direction (see the arrow in FIG. 13), so that the aluminano particles are dense and the fused state is obtained. It becomes possible to improve the airtightness further.

  Even in this bonding mode, the diameters of the heat exchanger side gas refrigerant pipe 31 and the gas side connection refrigerant pipe 32 may be different from each other as long as a sufficient bonding area can be secured.

(8-6) Other embodiment F
In the above embodiment, the case where the gas refrigerant pipe 41 and the gas refrigerant pipe 42 are made of copper has been described as an example.

  However, the present invention is not limited to this. For example, the gas refrigerant pipe 41 and the gas refrigerant pipe 42 may be made of aluminum or an aluminum alloy containing aluminum as a main component, and iron or iron as a main component. It may be comprised by the iron alloy contained as, and may be comprised by stainless steel.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 Air-conditioning outdoor unit 3 Air-conditioning indoor unit 10 Unit casing 20 Outdoor heat exchanger 21 Heat exchange part 21a Heat transfer fin 21b Flat multi-hole pipe 22, 23 Header collecting pipe 30A Gas refrigerant piping assembly (refrigerant piping assembly) )
30B Liquid refrigerant piping assembly (refrigerant piping assembly)
31 Heat Exchanger Side Gas Refrigerant Pipe 32 Gas Side Connection Refrigerant Pipe 33 Gas Side Aluminum Connection Portion 34 Gas Side Copper Connection Portion 35 Heat Exchanger Side Liquid Refrigerant Pipe 36 Liquid Side Connection Refrigerant Pipe 37 Liquid Side Aluminum Connection Portion 38 Gas Side Copper Connection 40 Expansion valve

JP 2013-130345 A

Claims (9)

A first refrigerant pipe (31, 33) made of aluminum or an aluminum alloy;
A second refrigerant pipe (32, 34) configured to have at least one of aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, and stainless steel;
A joining portion (33, 34, 37, 38) joining the first refrigerant pipe and the second refrigerant pipe by fusing a brazing material containing alumina particles;
A refrigerant pipe assembly (30A, 30B) comprising: The melting point of the alumina particles is 100 degrees or more lower than the melting point of the first refrigerant pipe.
The refrigerant piping assembly according to claim 1. The second refrigerant pipe is made of aluminum or an aluminum alloy.
The refrigerant piping assembly according to claim 1 or 2. The inner diameter and outer diameter of the first refrigerant pipe and the second refrigerant pipe are the same,
The area of the joint portion between the first refrigerant pipe and the second refrigerant pipe is wider than a cross-sectional area in a cross section perpendicular to the axial direction of the first refrigerant pipe and the second refrigerant pipe,
Used in an environment where the pressure of the refrigerant flowing inside may be 1.0 MPa or more,
The refrigerant piping assembly according to any one of claims 1 to 3. The melting point of the aluminano particles is lower than the softening temperature of the first refrigerant pipe,
The refrigerant piping assembly according to any one of claims 1 to 4. The joint does not contain zinc;
The refrigerant | coolant piping assembly of any one of Claim 1 to 5. Preparing a first refrigerant pipe made of aluminum or an aluminum alloy and a second refrigerant pipe made of at least one of aluminum, aluminum alloy, copper, copper alloy, and stainless steel When,
Bonding the first refrigerant pipe and the second refrigerant pipe by fusing a brazing material containing aluminano particles between the first refrigerant pipe and the second refrigerant pipe; and
The manufacturing method of the refrigerant | coolant piping assembly which has this. The inner diameter and outer diameter of the first refrigerant pipe and the second refrigerant pipe are the same,
The area of the joint portion between the first refrigerant pipe and the second refrigerant pipe is wider than a cross-sectional area in a cross section perpendicular to the axial direction of the first refrigerant pipe and the second refrigerant pipe.
The manufacturing method of the refrigerant | coolant piping assembly of Claim 7. The first refrigerant pipe and the second refrigerant pipe are pressed against each other when the brazing material containing aluminano particles is interposed between the first refrigerant pipe and the second refrigerant pipe. Apply pressure to become
The manufacturing method of the refrigerant | coolant piping assembly of Claim 7 or 8.

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