Air conditioner

Abstract

[Abstract] [Problem] To prevent a connection pipe connected to a heat transfer pipe from being broken when the connection pipe is bent during air conditioner installation. [Solution] An air conditioner (1) comprises: a plurality of heat transfer pipes (110) formed of aluminum or an aluminum alloy; connection pipes (120) connected to refrigerant inlet / outlet ports (114) of the heat transfer pipes and at least partially formed of aluminum or an aluminum alloy; and a fixing member (132) that fixes at least one of the connection pipes connected to each of the two refrigerant inlet / outlet ports provided in the heat transfer pipes to another member other than the connection pipe inside an indoor unit (2) of the air conditioner.

Description

air conditioner

[0001] The present invention relates to an air conditioner.

[0002] Conventionally, air conditioners equipped with multiple refrigerant pipes have been known. Patent Document 1 discloses a pipe connection structure including a first refrigerant pipe and a second refrigerant pipe. The first refrigerant pipe has a first section, a first extension section, a second section, a second extension section, and a third section, which are arranged in order. The second refrigerant pipe is inserted into the first refrigerant pipe and has a fourth section corresponding to the second section and a fifth section facing the third section. The opposing second and fourth sections improve the strength of the connection portion, and the brazing area is reduced by limiting the brazing portion to the fifth and third sections.

[0003] Patent No. 7227512

[0004] When installing an air conditioner, a service technician may bend the piping as needed to accommodate the installation of the indoor and outdoor units. At this time, the force applied to the connecting piping is applied to the joint between the heat exchanger's heat transfer tube and the connecting piping, causing the connecting piping to break at this joint.

[0005] The present invention has been made in view of the above-mentioned problems, and has an object to prevent the connecting pipe from breaking when the connecting pipe is bent during installation of the air conditioner.

[0006] The present invention is an air conditioner comprising a plurality of heat transfer tubes made of aluminum or an aluminum alloy, connecting pipes connected to refrigerant inlets and outlets of the heat transfer tubes and at least a portion of which is made of aluminum or an aluminum alloy, and fixing members for fixing at least one of the connecting pipes connected to each of the two refrigerant inlets and outlets provided on the heat transfer tubes to a member other than the connecting pipes inside an indoor unit of the air conditioner.

[0007] According to the present invention, when the connecting pipe is bent during installation of the air conditioner, the connecting pipe can be prevented from breaking.

[0008] Fig. 1 is an external configuration diagram showing an air conditioner. Fig. 2 is a diagram showing a refrigerant circuit of the air conditioner. Fig. 3 is a diagram showing an indoor exchanger. Fig. 4 is an enlarged view of a fixing member. Fig. 5 is a schematic cross-sectional view of a connection portion between a heat transfer tube and a connection pipe. Fig. 6 is an explanatory diagram of a sixth modified example. Fig. 7 is an explanatory diagram of a sixth modified example.

[0009] Fig. 1 is an external configuration diagram showing an air conditioner 1 according to this embodiment. The air conditioner 1 performs air conditioning by circulating a refrigerant in a refrigeration cycle (heat pump cycle). As shown in Fig. 1, the air conditioner 1 includes an indoor unit 2 installed indoors (the space to be air-conditioned), an outdoor unit 3 installed outdoors (outdoors), and a remote control 4 operated by a user.

[0010] The indoor unit 2 is equipped with a remote control communication unit 5. The remote control communication unit 5 transmits and receives predetermined signals to and from the remote control 4 via infrared communication or the like. For example, the remote control communication unit 5 receives signals such as an operation command, a stop command, a change in the set temperature, a change in the operation mode, or a timer setting from the remote control 4. Although not shown in Fig. 1 , the indoor unit 2 and the outdoor unit 3 are connected via refrigerant piping and also via a communication line.

[0011] Fig. 2 is a diagram showing the refrigerant circuit Q of the air conditioner 1 according to this embodiment. Note that the solid arrows shown in Fig. 2 indicate the flow of refrigerant during heating operation, and the dashed arrows shown in Fig. 2 indicate the flow of refrigerant during cooling operation.

[0012] In addition to the remote control communication unit 5, the indoor unit 2 is equipped with an indoor heat exchanger 6 and a cross-flow fan (also called a cross-flow fan or indoor fan) 7. In the indoor heat exchanger 6, heat exchange occurs between the refrigerant flowing through heat transfer tubes (described below) and the indoor air sent in from the cross-flow fan 7. The indoor heat exchanger 6 operates as a condenser or an evaporator depending on the switching of a four-way valve 13 (described below). The cross-flow fan 7 is installed near the indoor heat exchanger 6. The cross-flow fan 7 sends indoor air to the indoor heat exchanger 6 when driven by an indoor fan motor 8. The specific configuration of this indoor unit 2 will be described later.

[0013] The outdoor unit 3 includes a compressor 9, an outdoor heat exchanger 10, an outdoor fan 11, an outdoor expansion valve (expansion valve) 12, and a four-way valve 13. The compressor 9 compresses a low-temperature, low-pressure gas refrigerant by driving a compressor motor 14, and discharges it as a high-temperature, high-pressure gas refrigerant. In the outdoor heat exchanger 10, heat exchange occurs between the refrigerant flowing through the heat transfer tube and outside air sent in from the outdoor fan 11. The outdoor heat exchanger 10 operates as a condenser or an evaporator by switching the four-way valve 13.

[0014] As shown in Fig. 1, the outdoor fan 11 is installed near the outdoor heat exchanger 10. The outdoor fan 11 sends outside air to the outdoor heat exchanger 10 by driving an outdoor fan motor 11a. The outdoor expansion valve 12 has the function of reducing the pressure of the refrigerant condensed in the "condenser" (one of the outdoor heat exchanger 10 and the indoor heat exchanger 6). The refrigerant reduced in pressure in the outdoor expansion valve 12 is introduced to the "evaporator" (the other of the outdoor heat exchanger 10 and the indoor heat exchanger 6).

[0015] The four-way valve 13 switches the refrigerant flow path depending on the operating mode of the air conditioner 1. By switching the four-way valve 13, during cooling operation, the refrigeration cycle is established in which the refrigerant circulates in the order of the compressor 9, outdoor heat exchanger (condenser) 10, outdoor expansion valve 12, and indoor heat exchanger (evaporator) 6, as shown by the dashed arrow. Also, during heating operation, the four-way valve 13 switches the refrigeration cycle in which the refrigerant circulates in the order of the compressor 9, indoor heat exchanger (condenser) 6, outdoor expansion valve 12, and outdoor heat exchanger (evaporator) 10, as shown by the solid arrow. That is, in the refrigerant circuit Q in which the refrigerant circulates sequentially through the compressor 9, the "condenser," the outdoor expansion valve 12, and the "evaporator," one of the "condenser" and the "evaporator" is the outdoor heat exchanger 10, and the other is the indoor heat exchanger 6.

[0016] FIG. 3 is a schematic diagram of the indoor heat exchanger 6. The indoor heat exchanger 6 includes a plurality of fins 100, and a plurality of heat transfer tubes (hairpin pipes) 110 are provided to penetrate the fins 100. Each heat transfer tube 110 is connected at both ends to the ends of the adjacent heat transfer tube 110 via a return pipe 112. The return pipe 112 is U-shaped. Thus, the plurality of heat transfer tubes 110 are connected in series by the return pipes 112, forming a long refrigerant flow path. Two refrigerant inlets 114 of the heat transfer tubes 110 in the indoor heat exchanger 6 are respectively connected by insertion of connecting pipes 120. The connecting pipes 120 are connected to the heat transfer tubes 110 by brazing. Alternatively, the connecting pipes 120 may be inserted into the heat transfer tubes 110 and then crimped. The method for connecting the heat transfer tubes 110 and the connecting pipes 120 is not limited. The heat transfer pipe 110, the return pipe 112 and the connecting pipe 120 are all made of aluminum or an aluminum alloy.

[0017] Two connection pipes 120 connected to two refrigerant inlets and outlets 114 of the heat transfer pipe 110 are both fixed to the return pipe 112. In this embodiment, both connection pipes 120 are fixed to the return pipe 112a located closest to the refrigerant inlet and outlet 114 (the connection portion between the connection pipe 120 and the heat transfer pipe 110). When installing the air conditioner 1, the indoor unit 2 is installed indoors, and the outdoor unit 3 is installed outdoors. The connection pipe 120 of the indoor unit 2 is then bent appropriately by a service technician depending on the installation situation of the indoor unit 2. For example, in the example shown in FIG. 3 , the connection pipe 120 is bent at a portion 120b. When a portion of the connection pipe 120 is bent in this way, the resulting stress may cause the connection pipe 120 to break at the connection portion with the heat transfer pipe 110. In contrast, the connection pipe 120 in this embodiment is fixed to the return pipe 112 from the connection portion with the heat transfer pipe 110 to the bent portion. Therefore, stress caused by bending is prevented from being transmitted to the connection portion between the heat transfer tube 110 and the connection pipe 120, and it is possible to prevent the connection pipe 120 from breaking at the connection portion. Furthermore, by fixing the connection pipe 120 to the return pipe 112a at a position closest to the refrigerant inlet / outlet 114, it is possible to reduce the routing space for the connection pipe 120.

[0018] Furthermore, the straight portion 120a of the connecting pipe 120 is fixed to the return pipe 112. This improves the workability when fixing the connecting pipe 120 to the return pipe 112.

[0019] The straight section 120a of the connection pipe 120 is covered with a covering member 130, and is fixed to the return pipe 112a by a fixing member 132 via the covering member 130. The covering member 130 is made of a material with a lower thermal conductivity than the connection pipe. Specifically, the covering member 130 is made of rubber or resin. This prevents heat exchange between the refrigerant flowing through the return pipe 112a and the refrigerant flowing through the portion of the connection pipe 120 fixed to the return pipe 112a.

[0020] The fixing member 132 is made of resin. In this way, the fixing member 132 is made of a material softer than aluminum. This prevents the connection pipe 120 and the return pipe 112 from being scraped by the fixing member 132. Furthermore, using resin ensures sufficient strength for fixing.

[0021] FIG. 4 is an enlarged view of the fixing member 132. The fixing member 132 includes a belt portion 132a and a head portion 132b. The belt portion 132a is a strip-shaped member for bundling multiple members together. The head portion 132b is a member for fixing both ends of the belt portion 132a. The belt portion 132a binds the covering member 130 and the return pipe 112a together, and is fixed by the head portion 132b. The head portion 132b is positioned on the covering member 130, but not on the return pipe 112a. In other words, the head portion 132b contacts the covering member 130 but not the return pipe 112a. This configuration prevents the return pipe 112a from being damaged by the head portion 132b.

[0022] Furthermore, the fixing position where the connection pipe 120 and the return pipe 112 are fixed is the position on the return pipe 112 farthest from the fins 100, i.e., the bottom part of the U-shape of the return pipe 112. This makes it possible to ensure the bending diameter when bending the connection pipe 120.

[0023] As described above, in the air conditioner of this embodiment, the connecting pipe is fixed to the return pipe, so that the connecting pipe can be prevented from breaking when it is bent during installation of the air conditioner.

[0024] Furthermore, when the inserted portion of the connection pipe 120 into the heat transfer tube 110 is lengthened, as in the technology of Patent Document 1, the sound of the refrigerant flowing becomes a problem. FIG. 5 is a schematic cross-sectional view of the connection portion between the heat transfer tube 110 and the connection pipe 120. Arrows indicate the flow of refrigerant. When the connection portion between the heat transfer tube 110 and the connection pipe 120 is lengthened and the connection pipe 120 is inserted to the position where the fin 100 is disposed, the connection pipe 120 is contracted to reduce the diameter of its tip portion. This increases the wall thickness of the contracted portion 122. Furthermore, aluminum pipes are weaker than copper pipes, and therefore their wall thickness is greater than that of copper pipes. As a result, a relatively large step 200 is created in the flow path at the connection portion between the heat transfer tube 110 and the connection pipe 120. A vortex of the refrigerant occurs at this step 200, causing refrigerant noise. In contrast, the air conditioner 1 of this embodiment, with the above configuration, does not need to lengthen the inserted portion of the connection pipe 120 into the heat transfer tube 110. By shortening the narrowed pipe section 122 in this manner, refrigerant noise can be suppressed.

[0025] It should be noted that the present invention is not limited to the specific embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims, such as applying a modified example of one embodiment to another embodiment.

[0026] As a first such modified example, in the outdoor unit 3 as well, the connecting pipe may be fixed to the return pipe, similar to the indoor unit 2.

[0027] In a second modified example, at least one of the two connecting pipes 120 connected to the two refrigerant inlets and outlets 114 may be fixed to the return pipe 112. More preferably, when the indoor heat exchanger 6 operates as a condenser, the connecting pipe 120 connected to the refrigerant inlet and outlet 114, which serves as the refrigerant inlet, may be fixed to the return pipe 112.

[0028] In a third modified example, the connection pipe 120 only needs to be fixed to the return pipe 112, and the position and the number of fixing points are not limited to those described in the embodiment. The fixing point is preferably close to the connection portion between the heat transfer tube 110 and the connection pipe 120, but on the other hand, if there are restrictions due to the arrangement of other components, it does not have to be the closest return pipe 112. Furthermore, the connection pipe 120 may be fixed to multiple return pipes 112 at multiple points.

[0029] In a fourth modified example, the connecting pipe 120 may be fixed to a member other than the connecting pipe inside the indoor unit 2, and the fixing destination is not limited to the return pipe 112. For example, the connecting pipe 120 may be fixed to a housing inside the indoor unit 2.

[0030] In a fifth modification, at least one of the two connecting pipes 120 may be fixed to the return pipe 112a closest to the refrigerant inlet / outlet 114. For example, depending on the arrangement of other components of the air conditioner 1, it may be difficult to fix one connecting pipe 120 to the return pipe 112a closest to the refrigerant inlet / outlet 114. In such a case, the connecting pipe 120 may be fixed to a return pipe 112 other than the return pipe 112a closest to the refrigerant inlet / outlet 114. Note that, in this case as well, it is preferable to fix one connecting pipe 120 to the return pipe 112 as close to the refrigerant inlet / outlet 114 as possible. Furthermore, it may be difficult to fix both of the two connecting pipes 120 to the return pipe 112a closest to the refrigerant inlet / outlet 114. In such a case, both connecting pipes 120 may be fixed to a return pipe 112 other than the return pipe 112a closest to the refrigerant inlet / outlet 114. In this case, too, it is preferable that both of the connecting pipes 120 are fixed to the return pipe 112 as close as possible to the refrigerant inlet / outlet 114 .

[0031] 6 and 7 are explanatory diagrams of a sixth modified example. FIG. 6 is a schematic perspective view of a fixing portion according to the sixth modified example. FIG. 7 is a view of the fixing portion shown in FIG. 6 as viewed in the longitudinal direction of the heat transfer tube 110. In the sixth modified example, at least one of the connection pipes 120 may be arranged at a position overlapping (the same position as) the return pipe 112 in the longitudinal direction Y of the heat transfer tube 110, i.e., at a different position in the depth direction X of the air conditioner 1. In the example shown in FIG. 7 , the connection pipe 120 connected to the refrigerant outlet 114a side is arranged at a position overlapping with the return pipe 112 in the longitudinal direction Y. By arranging the connection pipe 120 at a position overlapping with the return pipe 112 in the longitudinal direction Y in this way, the space required for the connection pipe 120 can be reduced.

[0032] REFERENCE SIGNS LIST 1 Air conditioner 2 Indoor unit 3 Outdoor unit 4 Remote control 5 Remote control communication unit 6 Indoor heat exchanger 7 Cross flow fan 8 Indoor fan motor 9 Compressor 10 Outdoor heat exchanger 11 Outdoor fan 11a Outdoor fan motor 12 Outdoor expansion valve 13 Four-way valve 14 Compressor motor 100 Fin 110 Heat transfer tube 112 Return pipe 112a Return pipe 114 Refrigerant inlet / outlet 120 Connecting pipe 120a Straight section 120b Part 122 Shortened section 130 Covering member 132 Fixing member 200 Step

Claims

1. An air conditioner comprising: a plurality of heat transfer tubes formed of aluminum or an aluminum alloy; connecting pipes connected to refrigerant inlets and outlets of the heat transfer tubes and at least a portion of which is formed of aluminum or an aluminum alloy; and fixing members for fixing at least one of the connecting pipes connected to each of the two refrigerant inlets and outlets provided on the heat transfer tubes to a member other than the connecting pipes inside an indoor unit of the air conditioner.

2. The air conditioner according to claim 1, wherein the connecting pipe connected to the refrigerant inlet / outlet which serves as a refrigerant inlet when the heat exchanger having the heat transfer tube operates as a condenser is fixed to the other member.

3. The air conditioner according to claim 1, wherein each of the two connecting pipes is fixed to the other member by the fixing member.

4. The air conditioner according to claim 1, further comprising a return pipe connecting the heat transfer tubes together, wherein the connecting piping is fixed to the return pipe by the fixing member.

5. The air conditioner according to claim 4, wherein the connecting pipe is fixed to the return pipe via a covering member, and the covering member has a lower thermal conductivity than the connecting pipe.

6. The air conditioner according to claim 5, wherein the head portion of the fixing member contacts the covering member but does not contact the heat transfer tube.

7. The air conditioner according to claim 4, comprising a plurality of the return pipes, and the connecting piping is fixed to the return pipe closest to the refrigerant inlet / outlet.

8. The air conditioner according to claim 4, wherein the fixed position of the return pipe and the connecting pipe is the position of the return pipe that is farthest from the fins of the heat exchanger.

9. The air conditioner according to claim 4, wherein the connecting pipe is arranged at a position overlapping with the return pipe in the longitudinal direction of the heat transfer pipe.

10. The air conditioner according to claim 5, wherein the covering member is formed of rubber or resin.

11. The air conditioner according to claim 1, wherein the connecting pipe has a straight portion and is fixed to the other member at the straight portion.

12. The air conditioner according to claim 1, wherein the material of the fixing member is resin.

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