Air conditioning device

Abstract

Provided is an air conditioning device capable of achieving an optimal design in accordance with a target specification of each heat exchanger of an indoor unit and an outdoor unit. An air conditioning device is provided with: an indoor unit including an indoor heat transfer pipe formed from aluminum or an aluminum alloy (aluminum or the like), the indoor heat transfer pipe being connected to an indoor connection pipe formed from aluminum or the like; and an outdoor unit including an outdoor heat transfer pipe formed of aluminum or the like, the outdoor heat transfer pipe being connected to an outdoor connection pipe formed of aluminum or the like. The indoor heat transfer pipe is provided with an indoor heat exchange part provided with a plurality of indoor heat transfer plates, and an indoor joint part which is larger than the indoor heat exchange part in inner diameter and is inserted into the indoor connecting pipe. The outdoor heat transfer tube has an outdoor heat exchange part provided with a plurality of outdoor heat transfer plates, and an outdoor joint part having an inner diameter larger than that of the outdoor heat exchange part and inserted into the outdoor connection piping. The ratio of the inner diameter of the indoor joint part to the inner diameter of the indoor heat exchange part is larger than the ratio of the inner diameter of the outdoor joint part to the inner diameter of the outdoor heat exchange part.

Description

Technical Field

[0001] The present invention relates to an air conditioning device. Background Art

[0002] Heat exchangers in indoor and outdoor air conditioners typically use copper tubes for heat transfer, but to reduce costs, there's a growing trend toward using aluminum or aluminum alloy tubes. Because the multiple heat transfer plates (fins) surrounding the heat transfer tubes are made of aluminum or aluminum alloy, heat exchangers using aluminum tubes are called all-aluminum heat exchangers.

[0003] The heat exchanger's heat transfer tubes are connected to the refrigerant pipes. The connection between the heat transfer tubes and the refrigerant pipes is achieved by inserting the refrigerant pipes into the heat transfer tubes and securing them by brazing. In all-aluminum heat exchangers, the heat transfer tubes are aluminum, so the strength is low and this connection requires reinforcement.

[0004] By extending the overlap between the heat transfer tube and the piping, the strength of the connection can be ensured. However, extending the overlap lengthens the brazing portion, requiring more solder and increasing the brazing time. Therefore, a structure has been proposed that maintains the strength of the connection without extending the brazing portion (see, for example, Patent Document 1).

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-170142 Summary of the Invention

[0008] Problems to be solved by the invention

[0009] Establishing (optimizing) the structural dimensions of a heat exchanger that balances quality and productivity is an important design issue. However, achieving this balance in all-aluminum heat exchangers is more difficult.

[0010] Furthermore, the quality required of heat exchangers in indoor and outdoor units is not necessarily the same; in indoor units, priority is given to reducing the noise of refrigerant flow during operation, while in outdoor units, priority is given to productivity (processability).

[0011] Therefore, an object of the present invention is to provide an air conditioning apparatus that achieves both necessary quality and productivity.

[0012] Solutions to Problems

[0013] In view of the above problems, the present invention provides an air conditioning device, comprising:

[0014] an indoor unit including an indoor heat transfer tube formed of aluminum or an aluminum alloy, wherein at least a portion of the indoor heat transfer tube is connected to an indoor connecting pipe formed of aluminum or an aluminum alloy; and

[0015] The outdoor unit includes an outdoor heat transfer pipe formed of aluminum or an aluminum alloy, and at least a portion of the outdoor heat transfer pipe is connected to an outdoor connecting pipe formed of aluminum or an aluminum alloy.

[0016] The indoor heat transfer pipe has: an indoor heat exchange portion having a plurality of indoor heat transfer plates provided on the outer periphery; and an indoor joint portion having an inner diameter larger than that of the indoor heat exchange portion and inserted into the indoor connecting pipe.

[0017] The outdoor heat transfer pipe has: an outdoor heat exchange portion having a plurality of outdoor heat transfer plates provided on the outer periphery; and an outdoor joint portion having a larger inner diameter than the outdoor heat exchange portion and inserted into the outdoor connecting pipe.

[0018] The ratio of the inner diameter of the indoor joint portion to the inner diameter of the indoor heat exchange portion is greater than the ratio of the inner diameter of the outdoor joint portion to the inner diameter of the outdoor heat exchange portion.

[0019] Effects of the Invention

[0020] According to the present invention, an air-conditioning apparatus that achieves both required quality and productivity can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a diagram showing a configuration example of an air conditioning apparatus.

[0022] Figure 2 This is an enlarged view showing the appearance of an indoor heat exchanger included in the indoor unit and a portion thereof.

[0023] Figure 3 This is a diagram showing a first example of connecting the indoor heat transfer pipes and the indoor connecting pipes.

[0024] Figure 4 This is an enlarged view showing the appearance of an outdoor heat exchanger included in the outdoor unit and a portion thereof.

[0025] Figure 5 This is a diagram showing an example of connecting an outdoor heat transfer pipe and an outdoor connecting pipe.

[0026] Figure 6 This is a diagram showing a second example of connecting the indoor heat transfer pipes and the indoor connecting pipes.

[0027] In the picture:

[0028] 10 - Air conditioning unit, 11 - Indoor unit, 12 - Indoor heat exchanger, 13 - Indoor fan, 14 - Indoor fan motor, 20 - Outdoor unit, 21 - Compressor, 22 - Receiver, 23 - Four-way valve, 24 - Expansion valve, 25 - Outdoor heat exchanger, 26 - Outdoor fan, 27 - Outdoor fan motor, 28 - Control unit, 30 - Indoor heat transfer pipe, 31 - Indoor U-shaped connecting pipe, 32 - Indoor connecting pipe, 33 - Indoor heat exchange unit, 34 - Indoor heat exchange unit, 35 - Indoor heat exchange unit, 36 - Indoor heat exchange unit, 37 - Indoor heat exchange unit, 38 - Indoor heat exchange unit, 39 - Indoor heat exchange unit, 40 - Indoor heat exchange unit, 41 - Indoor heat exchange unit, 42 - Indoor heat exchange unit, 43 - Indoor heat exchange unit 4—indoor joint, 35—first indoor enlarged diameter portion, 36—second indoor enlarged diameter portion, 37—third indoor enlarged diameter portion, 38—opening, 40—outdoor heat transfer pipe, 41—outdoor U-shaped connecting pipe, 42—outdoor connecting pipe, 43—outdoor heat exchange portion, 44—outdoor joint, 45—first outdoor enlarged diameter portion, 46—second outdoor enlarged diameter portion, 47—third outdoor enlarged diameter portion, 48—opening, 50—indoor main pipe portion, 51—indoor thin-diameter portion. DETAILED DESCRIPTION

[0029] Figure 1 This figure shows an example configuration of an air conditioning system. Air conditioning system 10 includes an indoor unit 11 installed in the air-conditioned space (indoors) and an outdoor unit 20 installed outdoors. Air conditioning system 10 circulates refrigerant between indoor unit 11 and outdoor unit 20, exchanging heat with the indoor air, thereby adjusting the temperature, humidity, and other characteristics of the indoor air.

[0030] The indoor unit 11 and the outdoor unit 20 may each be composed of two or more units, or two or more indoor units 11 may be connected to one outdoor unit 20. Hydrofluorocarbons (HFCs) and hydrofluorocarbons (HFOs) may be used as refrigerants. Examples of HFCs include R410A and R32. Examples of HFOs include R1234yf.

[0031] The indoor unit 11 communicates with the remote controller and receives various signals such as operation commands, stop commands, commands to change set temperatures, commands to change operation modes, etc. The indoor unit 11 is connected to the outdoor unit 20 via a communication line and cooperates with the outdoor unit 20 to perform indoor air conditioning.

[0032] The indoor unit 11 starts up in response to an operating command from the remote control, and instructs the outdoor unit 20 to start up as well. The indoor unit 11 and the remote control can be connected via a communication line or wirelessly. After startup, the outdoor unit 20 adjusts the compressor speed, expansion valve opening, and other parameters, controlling the refrigerant circulation rate, etc., to maintain the indoor temperature at the set point.

[0033] The indoor unit 11 includes an indoor heat exchanger 12, an indoor fan 13, and an indoor fan motor 14. The indoor fan 13 is driven by the indoor fan motor 14 to draw in indoor air and deliver it to the indoor heat exchanger 12. The indoor heat exchanger 12 includes indoor heat transfer pipes through which refrigerant flows. The air entering the indoor heat exchanger 12 exchanges heat with the surfaces of the indoor heat transfer pipes. The air that has exchanged heat in the indoor heat exchanger 12 is discharged into the room.

[0034] The indoor unit 11 may also include various sensors for detecting indoor temperature, an indoor expansion valve, and the like.

[0035] The outdoor unit 20 includes a compressor 21, an accumulator 22, a four-way valve 23, an outdoor expansion valve 24, an outdoor heat exchanger 25, an outdoor fan 26 (air supply mechanism), and an outdoor fan motor 27. The compressor 21, such as a rotary compressor or a scroll compressor, is driven by a compressor motor to compress low-pressure gas refrigerant and discharge it as high-pressure gas refrigerant. The accumulator 22 is a container for storing reflux liquid during transient conditions and adjusts the refrigerant to an appropriate dryness. Dryness is the ratio of steam to wet steam, which represents a mixture of steam and fine droplets.

[0036] The four-way valve 23 is a valve that switches the flow path of the refrigerant according to the operating state (operating mode) of the air conditioning unit 10. The operating modes include cooling mode, heating mode, and air supply mode. The outdoor expansion valve 24 is a valve that reduces the pressure and expands the high-pressure refrigerant. The outdoor fan 26 is driven by the outdoor fan motor 27 to draw in outdoor air and send it to the outdoor heat exchanger 25. The outdoor heat exchanger 25 has an outdoor heat transfer pipe inside, through which the refrigerant flows, and is configured so that the air sent in contacts the surface of the outdoor heat transfer pipe to exchange heat. The air that has exchanged heat through the outdoor heat exchanger 25 is discharged to the outside.

[0037] The outdoor unit 20 also includes a control device 28. The control device 28 is connected to the compressor 21, the four-way valve 23, the outdoor expansion valve 24, the indoor fan motor 14, and the outdoor fan motor 27 to control them. Specifically, the control device 28 controls the speed of the compressor motor, the opening of the outdoor expansion valve 24, and the speeds of the indoor fan motor 14 and the outdoor fan motor 27. To control these functions, the outdoor unit 20 is also equipped with various sensors, such as a sensor for detecting the outside air temperature. The control device 28 performs these controls based on the information detected by these sensors.

[0038] The control device 28 may be installed in not only the outdoor unit 20 but also the indoor unit 11 , or its function may be divided into two and installed in both the indoor unit 11 and the outdoor unit 20 .

[0039] For example, during heating operation, the indoor heat exchanger 12 is used as a condenser, and the outdoor heat exchanger 25 is used as an evaporator. Therefore, as indicated by the arrows, the controller 28 circulates the refrigerant enclosed in the system in the order of the compressor 21, the four-way valve 23, the indoor heat exchanger 12, the outdoor expansion valve 24, the outdoor heat exchanger 25, the four-way valve 23, the accumulator 22, and the compressor 21.

[0040] The compressor 21 compresses the low-temperature, low-pressure gaseous refrigerant (refrigerant gas) and discharges it as a high-temperature, high-pressure refrigerant gas. The indoor heat exchanger 12 cools and condenses the refrigerant gas by exchanging heat with the indoor air. The outdoor expansion valve 24 decompresses the liquid refrigerant. The opening of the outdoor expansion valve 24 is adjusted by the control device 28 to obtain an appropriate amount of liquid. The outdoor heat exchanger 25 evaporates the refrigerant by exchanging heat with the outdoor air. The refrigerant is then transported to the accumulator 22 through the four-way valve 23 and returned to the compressor 21.

[0041] Figure 2 This is an enlarged view showing the appearance of the indoor heat exchanger 12 included in the indoor unit 11 and a portion thereof. Figure 2 (a) is a diagram showing the appearance of the indoor heat exchanger 12. Figure 2 (b) is an enlarged representation of Figure 2 The part (part A) surrounded by a circle in (a) is shown in FIG. Figure 2 (c) is an enlarged representation of Figure 2 The part (part B) surrounded by a circle in (a) is shown in FIG. Figure 2 As shown in (a), the indoor heat exchanger 12 includes a plurality of indoor heat transfer tubes 30, a U-shaped indoor U-shaped connecting pipe 31 connecting the indoor heat transfer tubes 30 to each other, and a plurality of heat transfer plates (heat sinks) arranged on the outer periphery of the indoor heat transfer tubes 30 extending in a straight line. It is a roughly U-shaped heat exchanger and is configured to surround the indoor fan 13.

[0042] The plurality of indoor heat transfer tubes 30 are interconnected by one or more indoor U-shaped connecting pipes 31 to form a flow path for the refrigerant. An indoor connecting pipe 32 is connected to one end and the other end of the plurality of indoor heat transfer tubes 30 connected by one or more indoor U-shaped connecting pipes 31.

[0043] Therefore, refrigerant can be supplied from the indoor connecting pipe 32 connected to one end of a plurality of indoor heat transfer pipes 30 connected by one or more indoor U-shaped connecting pipes 31, so that the refrigerant flows toward the other end, during which time heat is exchanged with the air, and the refrigerant is discharged from the other end to the indoor connecting pipe 32 connected to the other end.

[0044] Furthermore, the refrigerant flow path within the indoor heat exchanger 12 is not limited to one; two or more flow paths may be formed. In this case, two or more indoor connecting pipes 32 are connected to the refrigerant inlet side, and two or more indoor connecting pipes 32 are connected to the refrigerant outlet side. However, a collecting pipe may be used for each of the two or more indoor connecting pipes 32 on the inlet and outlet sides. Alternatively, a branch pipe may be provided in each of the two refrigerant pipes connecting the indoor unit 11 and the outdoor unit 20, and the two or more indoor connecting pipes 32 may be connected to the branch pipes.

[0045] like Figure 2 As shown in (a) and (b) of FIG. 1 , the indoor heat transfer tube 30 includes an indoor heat exchange portion 33 having fins on its outer periphery and an indoor joint portion 34 inserted into the end of the indoor connecting pipe 32. Therefore, the inner diameter of the portion of the indoor joint portion 34 inserted into the end of the indoor connecting pipe 32 is larger than the inner diameter of the indoor heat exchange portion 33.

[0046] In addition, if Figure 2 As shown in (c), for example, the two ends of the indoor U-shaped connecting pipe 31 are inserted into the indoor joints 34 of two adjacent indoor heat transfer pipes 30, thereby connecting the two indoor heat transfer pipes 30 via the indoor U-shaped connecting pipe 31. Furthermore, the two indoor heat transfer pipes 30 connected by a single indoor U-shaped connecting pipe 31 are not limited to two adjacent indoor heat transfer pipes 30. The two ends of the indoor U-shaped connecting pipe 31 also have the same shape as the ends of the indoor connecting pipe 32. Therefore, the inner diameter of the portion of the indoor joint 34 of each of the two indoor heat transfer pipes 30 into which the two ends of the indoor U-shaped connecting pipe 31 are respectively inserted is larger than the inner diameter of the indoor heat exchange portion 33 of each of the two indoor heat transfer pipes 30.

[0047] Figure 3 This is a diagram showing a first example of a connection structure between the indoor heat transfer pipe 30 and the indoor connecting pipe 32 . Figure 3 (a) is a cross-sectional view showing the A portion after the indoor connecting pipe 32 is inserted into the indoor heat transfer pipe 30. Figure 3 (b) is a cross-sectional view of the A portion of the indoor heat transfer pipe 30. In addition, the cross-sectional view of the B portion after the indoor U-shaped connecting pipe 31 is inserted into the indoor heat transfer pipe 30 is also the same as the cross-sectional view of the B portion of the indoor heat transfer pipe 30. Figure 3 The cross-sectional views shown in (a) and (b) are the same.

[0048] The indoor heat exchange section 33 is a portion having a plurality of fins provided on the outer periphery. The fins extend in a direction perpendicular to the direction in which the indoor heat transfer tube 30 extends and are arranged approximately in parallel at regular intervals. The indoor heat transfer tube 30 can be either a tube with a constant inner diameter and a smooth inner surface, or a tube with spiral grooves on the inner surface. By providing grooves on the inner surface, the inner surface area can be increased compared to a tube with a smooth inner surface. The grooves form a uniform liquid film inside the tube, thereby improving the heat transfer performance inside the tube. In addition, in the case of a tube with grooves on the inner surface, the diameter of the approximately circular opening formed by the portion most protruding toward the radial center of the tube is the inner diameter of the tube.

[0049] The indoor joint 34 is formed by expanding the end of the indoor heat transfer tube 30. One example of the expansion process is die forging, which is a cold forging process that reduces the outer diameter of a round bar or pipe while rotating a die and striking it.

[0050] The indoor joint 34 includes: a first indoor enlarged diameter portion 35, which is hollow inside, continuous with the indoor heat exchange portion 33, and whose diameter expands from one end toward the other end; a second indoor enlarged diameter portion 36, which is hollow inside, continuous with the first indoor enlarged diameter portion 35, has an inner diameter larger than the inner diameter of the indoor heat exchange portion 33, and whose diameter does not change from one end toward the other end; and a third indoor enlarged diameter portion 37, which is hollow inside, continuous with the second indoor enlarged diameter portion 36, and whose diameter expands from one end toward the other end.

[0051] The indoor connecting pipe 32 is inserted into the second indoor expanded diameter portion 36 via the third indoor expanded diameter portion 37. After the indoor connecting pipe 32 is inserted into the second indoor expanded diameter portion 36, solder is melted by a heating mechanism such as a burner and flows from the opening 38 between the third indoor expanded diameter portion 37 and the indoor connecting pipe 32 into the space between the second indoor expanded diameter portion 36 and the indoor connecting pipe 32. The solder is naturally cooled and fixed, thereby joining (brazing) the indoor heat transfer pipe 30 and the indoor connecting pipe 32. Aluminum solder, for example, can be used as the solder. Figure 3 The indoor connecting pipe 32 shown in (a) is an indoor connecting pipe in which the diameter of the front end located at the end portion on the indoor heat transfer pipe 30 side and other portions does not change.

[0052] Here, if Figure 3 As shown in (b), the inner diameter of the indoor heat exchange portion 33 of the indoor heat transfer pipe 30 is set to D1, and the inner diameter of the second indoor enlarged diameter portion 36 of the indoor joint 34 is set to D2. Figure 3 As shown in (a), the inner diameter of the indoor connecting pipe 32 is set to D3, and the outer diameter of the indoor connecting pipe 32 is set to D4.

[0053] For the purpose of improving quality (customer satisfaction), the indoor heat exchanger 33 is required to be designed so as to suppress the refrigerant flow noise.

[0054] Refrigerant flow noise is easily generated in locations where the flow path resistance varies significantly. For example, in locations where the flow path is locally narrow, such as at narrow sections of piping. Therefore, it is necessary to minimize the internal diameter taper of the indoor heat transfer pipe 30 and the indoor connecting pipe 32. Furthermore, it is desirable to minimize the difference between the internal diameter D1 of the indoor heat exchange section 33 of the indoor heat transfer pipe 30 and the internal diameter D3 of the indoor connecting pipe 32 at the indoor joint 34 connecting the indoor heat transfer pipe 30 and the indoor connecting pipe 32. In other words, D1 ≈ D3.

[0055] Furthermore, the inner diameter D2 of the second indoor expanded diameter portion 36 of the indoor joint 34 of the indoor heat transfer tube 30 must be larger than the outer diameter D4 of the indoor connecting pipe 32. However, increasing the inner diameter D2 of the second indoor expanded diameter portion 36 tends to increase the likelihood of cracking during tube expansion. Therefore, it is important to ensure that the inner diameter D2, which is used to suppress refrigerant flow noise, is of a size that achieves a balance between reducing refrigerant flow noise and ensuring ease of tube expansion.

[0056] Changes in flow resistance may also occur between the indoor heat transfer pipe 30 and the indoor U-shaped connecting pipe 31. Therefore, when the inner diameter of both ends of the indoor U-shaped connecting pipe 31 is set to D3, which is the same as the inner diameter of the indoor connecting pipe 32, it is desirable to design the pipe so that the aforementioned relationship D1≈D3 holds. Furthermore, when the outer diameter of the indoor U-shaped connecting pipe 31 is set to D4, which is the same as the outer diameter of the indoor connecting pipe 32, D2 needs to be larger than D4. It is important that D2 has a size that balances refrigerant flow noise reduction with pipe expansion processability.

[0057] To reduce refrigerant flow noise, it is desirable to minimize changes in flow resistance between the indoor heat transfer pipe 30 and the indoor connecting pipe 32, and between the indoor heat transfer pipe 30 and the indoor U-shaped connecting pipe 31. However, since refrigerant flow noise is louder between the indoor heat transfer pipe 30 and the indoor connecting pipe 32, it is also possible to minimize changes in flow resistance only between the indoor heat transfer pipe 30 and the indoor connecting pipe 32. Furthermore, since the indoor heat transfer pipe 30 and the indoor connecting pipe 32 are connected at both the refrigerant inlet and outlet, and since refrigerant flow noise is louder at the outlet, it is also possible to minimize changes in flow resistance only at the outlet.

[0058] Figure 4 This is an enlarged view showing the appearance of the outdoor heat exchanger 25 included in the outdoor unit 20 and a portion thereof. Figure 4 (a) shows the appearance of the outdoor heat exchanger 25. Figure 4(b) is an enlarged view of the portion (C portion) enclosed by a circle in FIG4(a). Figure 4 As shown in (a), the outdoor heat exchanger 25 includes a plurality of outdoor heat transfer tubes 40, a U-shaped outdoor U-shaped connecting pipe 41 connecting two outdoor heat transfer tubes 40, and a plurality of heat transfer plates (heat sinks) arranged on the outer periphery of the outdoor heat transfer tubes 40 extending in a straight line, and arranged in a manner surrounding the interior.

[0059] The plurality of outdoor heat transfer tubes 40 are connected to each other by an outdoor U-shaped connecting pipe 41 to form a flow path for the refrigerant to flow. An outdoor connecting pipe 42 is connected to one end and the other end of the plurality of outdoor heat transfer tubes 40 connected by the outdoor U-shaped connecting pipe 41.

[0060] Therefore, refrigerant can be supplied from the outdoor connecting pipe 42 connected to one end of multiple outdoor heat transfer pipes 40 connected by the outdoor U-shaped connecting pipe 41, so that the refrigerant flows toward the other end, during which time heat is exchanged with the air, and the refrigerant is discharged from the other end to the outdoor connecting pipe 42 connected to the other end.

[0061] like Figure 4 As shown in (b), the outdoor heat transfer pipe 40 includes an outdoor heat exchange portion 43 having heat dissipation fins on its outer periphery, and an outdoor joint portion 44 that is inserted into the end of the outdoor connecting pipe 42 or the end of the outdoor U-shaped connecting pipe 41. Therefore, the inner diameter of the portion of the outdoor joint portion 44 that is inserted into the end of the outdoor connecting pipe 42 or the end of the outdoor U-shaped connecting pipe 41 is larger than the inner diameter of the outdoor heat exchange portion 43.

[0062] Figure 5 1 is a diagram showing an example of a connection structure between the outdoor heat transfer pipe 40 and the outdoor connecting pipe 42 . Figure 5 (a) is a cross-sectional view showing the C portion after the outdoor connecting pipe 42 is inserted into the outdoor heat transfer pipe 40. Figure 5 (b) is a cross-sectional view of the C portion of the outdoor heat transfer tube 40 .

[0063] The outdoor heat exchange section 43 is a portion having a plurality of fins provided on the outer periphery. The fins extend in a direction perpendicular to the direction in which the outdoor heat transfer tube 40 extends and are arranged approximately in parallel at regular intervals. The outdoor heat transfer tube 40 can be either a tube with a constant inner diameter and a smooth inner surface, or a tube with spiral grooves on the inner surface. Similar to the indoor heat transfer tube 30, by providing grooves on the inner surface, the inner surface area can be increased compared to a tube with a smooth inner surface. The grooves form a uniform liquid film inside the tube, thereby improving the heat transfer performance inside the tube. In addition, in the case of a tube with grooves on the inner surface, the diameter of the approximately circular opening formed by the portion most protruding toward the radial center of the tube is the inner diameter of the tube.

[0064] The outdoor joint portion 44 is formed by performing a tube expansion process such as swaging on the end portion of the outdoor heat transfer tube 40 .

[0065] The outdoor joint 44 includes: a first outdoor enlarged diameter portion 45, which is hollow inside, is continuous with the outdoor heat exchange portion 43, and has a diameter that expands from one end toward the other end; a second outdoor enlarged diameter portion 46, which is hollow inside, is continuous with the first outdoor enlarged diameter portion 45, has an inner diameter that is larger than the inner diameter of the outdoor heat exchange portion 43, and has a diameter that does not change from one end toward the other end; and a third outdoor enlarged diameter portion 47, which is hollow inside, is continuous with the second outdoor enlarged diameter portion 46, and has a diameter that expands from one end toward the other end.

[0066] The outdoor connecting pipe 42 is inserted into the second outdoor expanded diameter portion 46 via the third outdoor expanded diameter portion 47. After the outdoor connecting pipe 42 is inserted into the second outdoor expanded diameter portion 46, a heating mechanism such as a burner is used to melt the solder, which flows from the widely opened opening 48 between the third outdoor expanded diameter portion 47 and the outdoor connecting pipe 42 between the second outdoor expanded diameter portion 46 and the outdoor connecting pipe 42. The solder is then naturally cooled, thereby fixing the outdoor heat transfer pipe 40 and the outdoor connecting pipe 42 by brazing. Figure 5 The outdoor connecting pipe 42 shown in (a) is an outdoor connecting pipe in which the diameter of the tip of the end portion located on the outdoor heat transfer pipe 40 side and other portions does not change.

[0067] Here, if Figure 5 As shown in (b), the inner diameter of the outdoor heat exchange portion 43 is set to D5, and the inner diameter of the second outdoor enlarged diameter portion 46 of the outdoor joint portion 44 is set to D6. Figure 5 As shown in (a), the inner diameter of the outdoor connecting pipe 42 is set to D7, and the outer diameter of the outdoor connecting pipe 42 is set to D8.

[0068] The outdoor unit 20 is installed outdoors and contains a device within the same housing that generates noise such as the sound of the compressor 21 motor, which is louder than the sound of the refrigerant flowing through the outdoor heat exchanger 25. Therefore, for customers, the sound of the refrigerant flowing is quieter than the sound of the compressor 21 motor, and since the motor sound itself is generated outdoors, it is not a sound of concern and they tend to tolerate it.

[0069] On the other hand, when the end of the outdoor heat transfer tube 40 is enlarged to form the outdoor joint 44, increasing the degree of tube expansion, that is, increasing the inner diameter D6 of the second outdoor enlarged diameter portion 46, may cause cracks. The occurrence of cracks will cause product defects and increase the defect rate.

[0070] To prevent cracking, the degree of tube expansion must be reduced. Furthermore, reducing the degree of tube expansion prevents the change in the inner diameter D1 of the indoor heat exchange portion 33 of the indoor heat transfer tube 30 and the inner diameter D3 of the indoor connecting pipe 32 from being minimized, as in the indoor heat exchanger 12. This results in a design that generates refrigerant flow noise.

[0071] The outdoor heat exchanger 25 tends to tolerate refrigerant flow noise. Therefore, as with the indoor heat exchanger 12, the inner diameter D5 of the outdoor heat exchange portion 43 and the inner diameter D7 of the outdoor connecting pipe 42 do not need to be roughly equal. Therefore, the outdoor heat exchanger 25 can reduce the degree of expansion at the end of the outdoor heat transfer pipe 40. This allows for stable processing, reduces cracking, lowers the defect rate, and improves productivity (processability). Furthermore, reducing the degree of expansion at the end of the outdoor heat transfer pipe 40 allows for a smaller outer diameter of the outdoor connecting pipe 42 inserted therein, thereby reducing manufacturing costs.

[0072] Therefore, for the indoor heat exchanger 12, it is envisioned to be used indoors, and a design that emphasizes the quality of quieting the refrigerant flow sound (low noise) is adopted. For the outdoor heat exchanger 25, it is envisioned to be used outdoors, and compared to the indoor unit 11, the refrigerant flow sound can be tolerated, so a design that emphasizes productivity and cost can be adopted. For the required specifications of each heat exchanger, the optimal design that takes into account quality, productivity, and cost can be achieved.

[0073] At this time, the ratio D2 / D1 of the inner diameter D2 of the indoor junction portion 34 relative to the inner diameter D1 of the indoor heat exchange portion 33 is greater than the ratio D6 / D5 of the inner diameter D6 of the outdoor junction portion 44 relative to the inner diameter D5 of the outdoor heat exchange portion 43. That is, the relationship D2 / D1 > D6 / D5 holds. The ratio D2 / D1 represents the indoor inner diameter ratio, and the ratio D6 / D5 represents the outdoor inner diameter ratio.

[0074] The inner diameter D1 of the indoor heat exchanger 33 and the inner diameter D5 of the outdoor heat exchanger 43 can be set to be approximately the same (D1 ≈ D5). In the outdoor heat exchanger 43, which tends to be more tolerant of refrigerant flow noise than the indoor heat exchanger 33, prioritizing reducing the incidence of cracks during tube expansion of the outdoor heat transfer tube 40, the inner diameter D6 of the outdoor junction 44 (the inner diameter of the second outdoor expanded diameter portion 46 of the outdoor junction 44) can be made smaller than the inner diameter D2 of the indoor junction 34 (the inner diameter of the second indoor expanded diameter portion 36 of the indoor junction 34). In other words, D2 > D6. Thus, the aforementioned relationship D2 / D1 > D6 / D5 is achieved.

[0075] The outdoor joint 44 can be expanded less than the indoor joint 34, so the outer diameter D8 of the outdoor connecting pipe 42 inserted into the outdoor joint 44 can be smaller than the outer diameter D4 of the indoor connecting pipe 32 inserted into the indoor joint 34. In other words, D4>D8 holds.

[0076] Specifically, when the processing dimensions of the indoor heat transfer tube 30 and the outdoor heat transfer tube 40 are set to D1 = 6 mm, D2 = 7.2 mm, D5 = 6 mm, and D6 = 6.5 mm, D2 / D1 = 1.20 and D6 / D5 = 1.08, and the relationship D2 / D1 > D6 / D5 holds. Furthermore, when the outer diameter dimensions of the indoor connecting pipe 32 and the outdoor connecting pipe 42 are set to D4 = 7 mm and D8 = 6.35 mm, the relationship D4 > D8 holds. Therefore, by setting these expanded pipe structural dimensions, an optimal design can be achieved, emphasizing quality (low noise) for the indoor heat exchanger 12 and productivity and cost for the outdoor heat exchanger 25.

[0077] like Figure 3 As shown in (a), the indoor joint portion 34 can be inserted and joined to the indoor connecting pipe 32 whose front end and other parts have the same diameter. Figure 5 As shown in (a), the outdoor joint portion 44 can also be inserted into and joined with the outdoor connection pipe 42 whose diameters at the front end and other parts do not change.

[0078] Furthermore, the indoor connecting pipe 32 and the outdoor connecting pipe 42 may be pipes whose distal ends located on the indoor heat transfer pipe 30 side and the outdoor heat transfer pipe 40 side have a diameter smaller than that of other portions. Figure 6 This figure shows an example of an indoor connecting pipe 32 having a smaller diameter at the distal end than the rest of the pipe. The indoor heat transfer pipe 30 includes an indoor heat exchange portion 33 and an indoor junction portion 34. The indoor junction portion 34 includes a first indoor enlarged diameter portion 35, a second indoor enlarged diameter portion 36, and a third indoor enlarged diameter portion 37.

[0079] The indoor connecting pipe 32 includes an indoor main pipe section 50 and an indoor small diameter section 51 located at an end portion on the indoor heat transfer pipe 30 side and having a smaller diameter than the indoor main pipe section 50. Figure 6 In the embodiment, an outdoor reduced diameter portion is provided between the indoor main pipe section 50 and the indoor reduced diameter portion 51. The diameter of this outdoor reduced diameter portion decreases from the indoor main pipe section 50 toward the indoor reduced diameter portion 51. The indoor reduced diameter portion 51 is formed at the front end of the indoor connecting pipe 32 and has a substantially constant diameter. When the indoor connecting pipe 32 of this structure is inserted and joined to the indoor joint 34, the outer surface of the portion of the indoor main pipe section 50 adjacent to the indoor reduced diameter portion 51 abuts the inner surface of the second indoor expanded diameter portion 36 of the indoor joint 34. The indoor reduced diameter portion 51 extends beyond the second indoor expanded diameter portion 36 and is inserted into the first indoor expanded diameter portion 35, allowing it to be further inserted into the indoor heat exchange section 33.

[0080] By melting solder and flowing it into the opening 38 between the third indoor expanded diameter portion 37 and the indoor main pipe section 50 of the indoor connecting pipe 32, the second indoor expanded diameter portion 36 and the portion of the indoor main pipe section 50 adjacent to the indoor narrowed diameter portion 51 are brazed, thereby joining the indoor heat transfer pipe 30 and the indoor connecting pipe 32. Furthermore, by inserting the indoor narrowed diameter portion 51 into the indoor heat exchange section 33, the overlapping length of the indoor heat transfer pipe 30 and the indoor connecting pipe 32 is increased, thereby improving the joint strength. Alternatively, a narrowed diameter portion such as the indoor narrowed diameter portion 51 may be provided at the distal ends of the indoor U-shaped connecting pipe 31, the outdoor U-shaped connecting pipe 41, and the outdoor connecting pipe 42.

[0081] The inner diameter of the indoor joint 34 can be set to the inner diameter of the second indoor expanded diameter portion 36, but is not limited to this. It can also be the inner diameter of the indoor joint 34 at a position in the indoor connecting pipe 32 corresponding to the front end of the indoor main pipe 50 (including a pipe without a narrow diameter portion), or it can be the average value of the inner diameter of the indoor joint 34.

[0082] In addition, the inner diameter of the outdoor joint 44 can be set to the inner diameter of the second outdoor expansion portion 46, but is not limited to this. It can also be the inner diameter of the outdoor joint 44 at a position corresponding to the front end of the outdoor main pipe (including a pipe without a narrow diameter portion) in the outdoor connecting pipe 42, or it can be the average value of the inner diameter of the outdoor joint 44.

[0083] Therefore, the relationship holds true that the ratio of the inner diameter of the indoor junction 34 at the position corresponding to the front end of the indoor main pipe 50 to the inner diameter D1 of the indoor heat exchanger 33 is greater than the ratio of the inner diameter of the outdoor junction 44 at the position corresponding to the front end of the outdoor main pipe to the inner diameter D5 of the outdoor heat exchanger 43. Furthermore, the relationship holds true that the ratio of the average inner diameter of the indoor junction 34 to the inner diameter D1 of the indoor heat exchanger 33 is greater than the ratio of the average inner diameter of the outdoor junction 44 to the inner diameter D5 of the outdoor heat exchanger 43. Furthermore, the relationship holds true that the difference between the inner diameter D1 of the indoor heat exchanger 33 and the inner diameter D3 of the indoor main pipe 50, i.e., the inner diameter D3 of the indoor connecting pipe 32, is smaller than the difference between the inner diameter D5 of the outdoor heat exchanger 43 and the inner diameter D7 of the outdoor main pipe, i.e., the inner diameter D7 of the outdoor connecting pipe 42, i.e., |D1-D3|<|D5-D7|.

[0084] The indoor U-shaped connecting pipe 31 is also the same as the indoor connecting pipe 32. In the case of a pipe whose front end at the end portion located on the indoor heat transfer pipe 30 side is thinner in diameter than other portions, it has an indoor main pipe portion and an indoor thin-diameter portion. In the case of a pipe whose front end and other portions do not change in diameter, it has an indoor main pipe portion. The outdoor U-shaped connecting pipe 41 is also the same as the outdoor connecting pipe 42. In the case of a pipe whose front end at the end portion located on the outdoor heat transfer pipe 40 side is thinner in diameter than other portions, it has an outdoor main pipe portion and an outdoor thin-diameter portion. In the case of a pipe whose front end and other portions do not change in diameter, it has an outdoor main pipe portion.

[0085] Therefore, the relationship holds true that the ratio of the inner diameter of the indoor junction 34 at a position corresponding to the front end of the indoor main pipe to the inner diameter D1 of the indoor heat exchanger 33 is greater than the ratio of the inner diameter of the outdoor junction 44 at a position corresponding to the front end of the outdoor main pipe to the inner diameter D5 of the outdoor heat exchanger 43. Furthermore, the relationship holds true that the ratio of the average value of the inner diameter of the indoor junction 34 to the inner diameter D1 of the indoor heat exchanger 33 is greater than the ratio of the average value of the inner diameter of the outdoor junction 44 to the inner diameter D5 of the outdoor heat exchanger 43. Furthermore, the relationship holds true that the difference between the inner diameter D1 of the indoor heat exchanger 33 and the inner diameter of the indoor main pipe, i.e., the inner diameter of the indoor U-shaped connecting pipe 31, is smaller than the difference between the inner diameter D5 of the outdoor heat exchanger 43 and the inner diameter of the outdoor main pipe, i.e., the inner diameter of the outdoor U-shaped connecting pipe 41.

[0086] Furthermore, the outer diameter of the indoor main pipe section 50 of the indoor connecting pipe 32 is larger than the outer diameter of the outdoor main pipe section of the outdoor connecting pipe 42. The outer diameter of the indoor main pipe section of the indoor U-shaped connecting pipe 31 is larger than the outer diameter of the outdoor main pipe section of the outdoor U-shaped connecting pipe 41.

[0087] As described above, by providing the air conditioning apparatus of the present invention, it is possible to achieve an optimal design that takes into account the required specifications for each heat exchanger, quality, productivity, and cost.

[0088] So far, the air-conditioning device of the present invention has been described in detail based on the above-mentioned embodiment, but the present invention is not limited to the above-mentioned embodiment. It can be changed in other embodiments, additions, changes, deletions, etc. within the scope that can be thought of by people in this field. Any method is included in the scope of the present invention as long as it plays the role and effect of the present invention.

[0089] Therefore, either or both of the indoor heat transfer pipe 30 and the indoor connecting pipe 32 or the indoor heat transfer pipe 30 and the indoor U-shaped connecting pipe 31 may be designed to reduce the change in flow path resistance for suppressing the refrigerant flow sound.

Claims

1. An air conditioning device, characterized in that: include: an indoor unit comprising an indoor heat transfer tube formed of aluminum or an aluminum alloy, at least a portion of the indoor heat transfer tube being connected to an indoor connecting pipe formed of aluminum or an aluminum alloy; as well as The outdoor unit includes an outdoor heat transfer pipe formed of aluminum or an aluminum alloy, at least a portion of the outdoor heat transfer pipe is connected to an outdoor connecting pipe formed of aluminum or an aluminum alloy, The indoor heat transfer pipe comprises: an indoor heat exchange portion having a plurality of indoor heat transfer plates provided on the outer periphery; and an indoor joint portion having an inner diameter larger than that of the indoor heat exchange portion and inserted into the indoor connecting pipe. The outdoor heat transfer pipe comprises: an outdoor heat exchange portion having a plurality of outdoor heat transfer plates provided on the outer periphery; and an outdoor joint portion having an inner diameter larger than that of the outdoor heat exchange portion and inserted into the outdoor connecting pipe. A ratio of an inner diameter of the indoor joint portion to an inner diameter of the indoor heat exchange portion is greater than a ratio of an inner diameter of the outdoor joint portion to an inner diameter of the outdoor heat exchange portion.

2. The air conditioning device according to claim 1, characterized in that The indoor joint portion includes: a first indoor enlarged diameter portion whose diameter increases from one end toward the other end; and a second indoor enlarged diameter portion which is continuous with the first indoor enlarged diameter portion, has an inner diameter larger than the inner diameter of the indoor heat exchange portion, and has a diameter that does not change from one end toward the other end. The outdoor joint portion includes: a first outdoor enlarged diameter portion whose diameter increases from one end toward the other end; and a second outdoor enlarged diameter portion which is continuous with the first outdoor enlarged diameter portion, has an inner diameter larger than the inner diameter of the outdoor heat exchange portion, and has a diameter that does not change from one end toward the other end. A ratio of an inner diameter of the second indoor expanded diameter portion to an inner diameter of the indoor heat exchange portion is greater than a ratio of an inner diameter of the second outdoor expanded diameter portion to an inner diameter of the outdoor heat exchange portion.

3. The air conditioning device according to claim 1, wherein The indoor connecting pipe includes an indoor main pipe portion and an indoor thin-diameter portion located at an end portion on the indoor heat transfer pipe side and having a diameter smaller than that of the indoor main pipe portion, or includes the indoor main pipe portion. The outdoor connecting pipe includes an outdoor main pipe portion and an outdoor thin-diameter portion located at an end portion on the outdoor heat transfer pipe side and having a diameter smaller than that of the outdoor main pipe portion, or includes the outdoor main pipe portion. The ratio of the inner diameter of the indoor joint portion at a position corresponding to the front end of the indoor main pipe portion to the inner diameter of the indoor heat exchange portion is greater than the ratio of the inner diameter of the outdoor joint portion at a position corresponding to the front end of the outdoor main pipe portion to the inner diameter of the outdoor heat exchange portion.

4. The air conditioning device according to claim 1, wherein A ratio of an average value of an inner diameter of the indoor joint portion to an inner diameter of the indoor heat exchange portion is greater than a ratio of an average value of an inner diameter of the outdoor joint portion to an inner diameter of the outdoor heat exchange portion.

5. The air conditioning device according to claim 1, wherein The indoor connecting pipe includes an indoor main pipe portion and an indoor thin-diameter portion located at an end portion on the indoor heat transfer pipe side and having a diameter smaller than that of the indoor main pipe portion, or includes the indoor main pipe portion. The outdoor connecting pipe includes an outdoor main pipe portion and an outdoor thin-diameter portion located at an end portion on the outdoor heat transfer pipe side and having a diameter smaller than that of the outdoor main pipe portion, or includes the outdoor main pipe portion. A difference between an inner diameter of the indoor heat exchange portion and an inner diameter of the indoor main pipe portion is smaller than a difference between an inner diameter of the outdoor heat exchange portion and an inner diameter of the outdoor main pipe portion.

6. The air conditioning device according to claim 1, characterized in that The inner diameter of the indoor joint portion is larger than the inner diameter of the outdoor joint portion.

7. The air conditioning device according to claim 1, characterized in that The outer diameter of the indoor connecting pipe is larger than the outer diameter of the outdoor connecting pipe.

8. The air conditioning device according to claim 1, wherein The indoor connecting pipe includes an indoor main pipe portion and an indoor thin-diameter portion located at an end portion on the indoor heat transfer pipe side and having a diameter smaller than that of the indoor main pipe portion, or includes the indoor main pipe portion. The outdoor connecting pipe includes an outdoor main pipe portion and an outdoor thin-diameter portion located at an end portion on the outdoor heat transfer pipe side and having a diameter smaller than that of the outdoor main pipe portion. The outer diameter of the indoor main pipe portion is larger than the outer diameter of the outdoor main pipe portion.

9. An air conditioning device, characterized in that: include: an indoor unit comprising an indoor heat transfer tube formed of aluminum or an aluminum alloy, at least a portion of the indoor heat transfer tube being connected to an indoor U-shaped connecting pipe formed of aluminum or an aluminum alloy; as well as The outdoor unit includes an outdoor heat transfer pipe formed of aluminum or an aluminum alloy, at least a portion of which is connected to an outdoor U-shaped connecting pipe formed of aluminum or an aluminum alloy. The indoor heat transfer pipe comprises: an indoor heat exchange portion having a plurality of indoor heat transfer plates provided on the outer periphery; and an indoor joint portion having an inner diameter larger than that of the indoor heat exchange portion and inserted into the indoor U-shaped connecting pipe. The outdoor heat transfer pipe comprises: an outdoor heat exchange portion having a plurality of outdoor heat transfer plates provided on the outer periphery; and an outdoor joint portion having an inner diameter larger than that of the outdoor heat exchange portion and inserted into the outdoor U-shaped connecting pipe. A ratio of an inner diameter of the indoor joint portion to an inner diameter of the indoor heat exchange portion is greater than a ratio of an inner diameter of the outdoor joint portion to an inner diameter of the outdoor heat exchange portion.

10. The air conditioning device according to claim 9, characterized in that The indoor joint portion includes: a first indoor enlarged diameter portion whose diameter increases from one end toward the other end; and a second indoor enlarged diameter portion which is continuous with the first indoor enlarged diameter portion, has an inner diameter larger than the inner diameter of the indoor heat exchange portion, and has a diameter that does not change from one end toward the other end. The outdoor joint portion includes: a first outdoor enlarged diameter portion whose diameter increases from one end toward the other end; and a second outdoor enlarged diameter portion which is continuous with the first outdoor enlarged diameter portion, has an inner diameter larger than the inner diameter of the outdoor heat exchange portion, and has a diameter that does not change from one end toward the other end. A ratio of an inner diameter of the second indoor expanded diameter portion to an inner diameter of the indoor heat exchange portion is greater than a ratio of an inner diameter of the second outdoor expanded diameter portion to an inner diameter of the outdoor heat exchange portion.

11. The air conditioning device according to claim 9, characterized in that The indoor U-shaped connecting pipe includes an indoor main pipe portion and an indoor thin-diameter portion located at the end portion on the indoor heat transfer pipe side and having a diameter smaller than that of the indoor main pipe portion, or includes the indoor main pipe portion. The outdoor U-shaped connecting pipe includes an outdoor main pipe portion and an outdoor thin-diameter portion located at an end portion on the outdoor heat transfer pipe side and having a diameter smaller than that of the outdoor main pipe portion, or includes the outdoor main pipe portion. The ratio of the inner diameter of the indoor joint portion at a position corresponding to the front end of the indoor main pipe portion to the inner diameter of the indoor heat exchange portion is greater than the ratio of the inner diameter of the outdoor joint portion at a position corresponding to the front end of the outdoor main pipe portion to the inner diameter of the outdoor heat exchange portion.

12. The air conditioning device according to claim 9, characterized in that A ratio of an average value of an inner diameter of the indoor joint portion to an inner diameter of the indoor heat exchange portion is greater than a ratio of an average value of an inner diameter of the outdoor joint portion to an inner diameter of the outdoor heat exchange portion.

13. The air conditioning device according to claim 9, characterized in that The indoor U-shaped connecting pipe includes an indoor main pipe portion and an indoor thin-diameter portion located at the end portion on the indoor heat transfer pipe side and having a diameter smaller than that of the indoor main pipe portion, or includes the indoor main pipe portion. The outdoor U-shaped connecting pipe includes an outdoor main pipe portion and an outdoor thin-diameter portion located at an end portion on the outdoor heat transfer pipe side and having a diameter smaller than that of the outdoor main pipe portion, or includes the outdoor main pipe portion. A difference between an inner diameter of the indoor heat exchange portion and an inner diameter of the indoor main pipe portion is smaller than a difference between an inner diameter of the outdoor heat exchange portion and an inner diameter of the outdoor main pipe portion.

14. The air conditioning device according to claim 9, characterized in that The inner diameter of the indoor joint portion is larger than the inner diameter of the outdoor joint portion.

15. The air conditioning device according to claim 9, characterized in that The outer diameter of the indoor U-shaped connecting pipe is larger than the outer diameter of the outdoor U-shaped connecting pipe.

16. The air conditioning device according to claim 9, characterized in that The indoor U-shaped connecting pipe includes an indoor main pipe portion and an indoor thin-diameter portion located at the end portion on the indoor heat transfer pipe side and having a diameter smaller than that of the indoor main pipe portion, or includes the indoor main pipe portion. The outdoor U-shaped connecting pipe includes an outdoor main pipe portion and an outdoor thin-diameter portion located at an end portion on the outdoor heat transfer pipe side and having a diameter smaller than that of the outdoor main pipe portion. The outer diameter of the indoor main pipe portion is larger than the outer diameter of the outdoor main pipe portion.

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