JP7276055B2 - switching unit - Google Patents

Description

The present invention relates to a switching unit.

2. Description of the Related Art Conventionally, a switching unit is known that is provided between one or more outdoor units and multiple indoor units in a multi-room air conditioner and has a function of switching between cooling operation and heating operation. The switching unit is a unit that combines refrigerant pipes, a plurality of electromagnetic valves, and the like that constitute a part of the refrigerant circuit of the multi-room air conditioner. In the switching unit, one or a plurality of outdoor units and a plurality of indoor units are connected by three refrigerant pipes, a high-pressure gas pipe, a low-pressure gas pipe, and a liquid pipe, and cooling operation and heating operation are performed for each indoor unit. It is provided in a multi-room air conditioner that can selectively perform so-called cooling/heating free operation. The operation of the indoor unit is switched between the cooling operation and the heating operation by selecting the flow path connected to the unit.

Further, in recent years, it has been desired to switch cooling and heating of more indoor units with one switching unit. For example, one switching unit is proposed to connect 12 indoor units. In the switching unit connected to a large number of indoor units in this way, the volume of the refrigerant pipes inside the housing increases due to the increase in the number of refrigerant pipes arranged in the housing.

The switching unit is generally placed in a narrow space such as a ceiling space, and the size of the space where the switching unit can be installed is limited. . Furthermore, considering installation work in the ceiling space, it is difficult to secure a large space for the switching unit in the ceiling space. If the dimension between the refrigerant pipes is simply increased, the dimensions of the housing of the switching unit increase due to the increase in the number of refrigerant pipes arranged inside the housing. Therefore, it is physically difficult to increase the dimension between refrigerant pipes.

Further, the inside of the main body case is filled with a heat insulating material so as to prevent dew condensation from occurring on the refrigerant pipes and solenoid valves accommodated therein. For example, urethane foam, which is a foamed heat insulating material, is used as the material of the heat insulating material. As the foamed heat insulating material, for example, a two-liquid simple foam hard urethane foam is used, which is a mixture of liquid A mainly containing isocyanate and liquid B mainly containing polyol. By injecting the liquid stock solution immediately after mixing the A liquid and the B liquid into the inside of the main body case of the switching unit, the A liquid and the B liquid react inside the main body case and the liquid stock solution foams. , the inside of the housing is filled with foam insulation.

JP 2014-25668 A

In recent years, there has been a demand for switching cooling and heating of more indoor units with a single switching unit. For example, it has been proposed that 12 indoor units are connected to one switching unit, and each of the 12 indoor units can be switched between cooling and heating. In the switching unit connected to a large number of indoor units in this manner, the refrigerant pipes arranged inside the main body case increase, and the density of the refrigerant pipes increases inside the main body case.

The switching unit is provided with a plurality of capillary tubes for reducing the pressure difference between the refrigerant inflow side and the refrigerant outflow side of the electromagnetic valve that switches between the cooling operation and the heating operation. As the refrigerant flows through the capillary tube, the pressure of the refrigerant is reduced, but flow noise (refrigerant noise) is generated when the refrigerant flows through the capillary tube. In order to reduce this flow noise, a butyl rubber sheet is attached to each capillary tube.

However, when the piping density in the body case of the switching unit increases, the dimension between the refrigerant pipes becomes narrow. When the capillary tubes are placed between the refrigerant pipes, it is difficult to secure a space for the operator's fingers to put the butyl rubber sheet on each capillary tube, making it difficult to attach the butyl rubber to the capillary tubes. becomes. Therefore, if the dimension between the refrigerant pipes is increased and the capillary tubes are arranged between them, the operation of attaching the butyl rubber to the capillary tubes becomes easier. body size increases. If the size of the housing of the switching unit increases, there is a risk of construction problems such as difficulty in installation.

The disclosed technique has been made in view of the above, and an object thereof is to provide a switching unit that facilitates the operation of attaching butyl rubber to a capillary tube while keeping the housing size small.

In one aspect, the switching unit disclosed in the present application is connected to one or more outdoor units and multiple indoor units. The switching unit includes a main body case, and a first refrigerant pipe, a second refrigerant pipe, and a third refrigerant pipe, which are arranged in order in the main body case in a direction from the top surface to the bottom surface of the main body case. Prepare. A first electromagnetic valve is connected to the first refrigerant pipe and the second refrigerant pipe, and is opened when the indoor unit performs a heating operation. The second solenoid valve and the third solenoid valve communicate and block communication between a high-pressure side and a low-pressure side in a refrigerant flow path formed by the first refrigerant pipe, the second refrigerant pipe, and the third refrigerant pipe. is opened and closed when A fourth solenoid valve is connected to the third refrigerant pipe and the fourth refrigerant pipe, and is opened when the indoor unit performs a cooling operation. A first pressure reducing mechanism is arranged in the vicinity of the first refrigerant pipe, and reduces a pressure difference between both ends of the first solenoid valve in accordance with operations of the second solenoid valve and the third solenoid valve. A second pressure reducing mechanism is arranged near the third refrigerant pipe, and reduces the pressure difference between both ends of the fourth solenoid valve according to the operations of the second solenoid valve and the third solenoid valve. The first noise reduction member is attached to the first pressure reducing mechanism after connecting the first pressure reducing mechanism to the second solenoid valve and the third solenoid valve. The second noise reduction member is attached to the second pressure reducing mechanism after connecting the second pressure reducing mechanism to the second solenoid valve and the third solenoid valve.

In one aspect, the present invention makes it possible to reduce the size of the housing while facilitating the operation of attaching butyl rubber to the capillary tube.

1 is a schematic diagram of an air conditioning system according to an embodiment; FIG. 3 is a perspective view of the switching unit 1; FIG. 3 is a perspective view of a switching mechanism 10 mounted on the switching unit 1; FIG. 2 is a side view of a single switching mechanism 10; FIG. It is the figure which looked at two sets of switching mechanisms 10 from the upper surface. 3 is a front view of the switching mechanism 10; FIG. 4 is a diagram for explaining brazing of the joint pipe 130 in the first electromagnetic valve 111; FIG. FIG. 3 is a perspective view for explaining brazing of the first solenoid valve 111 and the secondary high-pressure gas pipe 11a; It is a perspective view showing the connection state of the sub-low-pressure gas pipe 12a. It is a perspective view of the sub-low-pressure gas pipe 12a. It is a side view of the sub-low-pressure gas pipe 12a. 4 is a rear view of the switching mechanism 10; FIG. Fig. 2 is a rear view of the switching mechanism 10 with the coil portions of the solenoid valves removed; FIG. 10 is a diagram showing a placement state of the switching mechanism group 100 when butyl rubber is pasted. FIG. 15 is a view of the switching mechanism group 100 in FIG. 14 taken along arrow D1; 15 is a view of the switching mechanism group 100 in FIG. 14 as viewed from arrow D2. FIG. 3 is a plan view of the switching unit 1 as seen from above; FIG. 4 is a diagram showing a state in which an upper surface 161 of the main body case 16 is removed; FIG. It is a figure showing the process which foaming heat insulating material foams, when the distance between refrigerant|coolant pipes is short. 4 is a flow chart showing an outline of a manufacturing process of the switching unit 1. FIG. FIG. 11 is a plan view for explaining brazing of the second refrigerant pipe 102 and the third refrigerant pipe 103 to the first electromagnetic valve 111 and the fourth electromagnetic valve 114; FIG. 11 is a perspective view for explaining brazing of the second refrigerant pipe 102 and the third refrigerant pipe 103 to the first electromagnetic valve 111 and the fourth electromagnetic valve 114; FIG. 11 is a plan view for explaining brazing of the second capillary tube 122 and the third capillary tube 123 to the second solenoid valve 112 and the third solenoid valve 113; FIG. 11 is a perspective view for explaining brazing of the second capillary tube 122 and the third capillary tube 123 to the second solenoid valve 112 and the third solenoid valve 113; It is a perspective view of a low-pressure gas pipe set. It is a perspective view of a high-pressure gas pipe set. 1 is a perspective view of an example of piping sub-sets 100A-100C. FIG. FIG. 10 is a diagram for explaining a state in which the piping subassembly 100A is incorporated in the support base 200; FIG. 4 is an external perspective view of piping subgroups 100A to 100C. Fig. 10 is a front perspective view of the piping assembly 100D to which the electromagnetic valve partition plate 171 is attached. FIG. 10 is a perspective view of the piping assembly 100D with the electromagnetic valve partition plate 171 attached, as seen from the rear side. FIG. 4 is a perspective view for explaining attachment of a butyl rubber sheet; It is a figure showing the process which mounts the piping assembly 100D on the outer shell 602. FIG. Fig. 3 is a perspective view of a state in which an indoor unit side liquid pipe connecting pipe 15 is connected to a secondary liquid pipe 13a; Fig. 3 is a perspective view of a state in which a pipe heat insulating material 131 and a pipe heat insulating material 151 are attached to the secondary liquid pipe 13a and the indoor unit side liquid pipe connecting pipe 15; FIG. 10 is a perspective view of a state in which the switching mechanism group 100, the secondary liquid pipe 13a, and the indoor unit side liquid pipe connection pipe 15 are mounted on the outer barrel 602; FIG. 3 is a perspective view of the switching unit 1 as seen from the bottom surface 166 side; FIG. 3 is a perspective view of the switching unit 1 viewed from the upper surface 161 side;

Hereinafter, embodiments of the switching unit disclosed in the present application will be described in detail based on the drawings. It should be noted that the switching unit disclosed in the present application is not limited to the following embodiments.

FIG. 1 is a schematic diagram of an air conditioning system according to an embodiment. The air-conditioning system according to this embodiment includes a switching unit 1 , an outdoor unit 2 and a plurality of indoor units 3 . Here, although the case where one outdoor unit 2 is connected to one switching unit 1 is described in FIG. 1 , a plurality of outdoor units 2 may be connected to the switching unit 1 via a branching device.

The switching unit 1 has a plurality of switching mechanisms 10 corresponding to each of the 12 indoor units 3 , and switches the flow path of the refrigerant for each indoor unit 3 . In this embodiment, the switching unit 1 has 12 switching mechanisms 10 . The switching mechanism 10 is connected to a high-pressure gas pipe 11 and a low-pressure gas pipe 12 which are refrigerant pipes extending from the outdoor unit 2 . Also, the indoor unit side gas connection pipe 14 extending from the switching mechanism 10 to the corresponding indoor unit 3 is connected to the indoor unit gas pipe 33 of the indoor unit 3 . Then, the switching mechanism 10 selectively switches the connection of the refrigerant pipe connected to the indoor-unit-side gas connecting pipe 14 to either the high-pressure gas pipe 11 or the low-pressure gas pipe 12 . Further, the switching mechanism 10 connects the liquid pipe 13 connected to the outdoor unit 2 and the indoor unit liquid pipe 34 of the indoor unit 3 through the indoor unit side liquid pipe connection pipe 15 .

Here, one end of the high pressure gas pipe 11 is connected to the outdoor unit 2, and the other end is connected to one end of the secondary high pressure gas pipe 11a provided with a branch pipe connected to each switching mechanism 10 inside the switching unit 1. . The secondary high-pressure gas pipe 11 a is a pipe arranged inside the switching unit 1 . When the number of indoor units 3 is more than 12, the other end of the secondary high-pressure gas pipe 11a is connected to the switching mechanism 10 of another switching unit 1 . On the other hand, when the number of indoor units 3 is 12 or less, the other end of the secondary high-pressure gas pipe 11a is closed without being connected to the switching mechanism 10 of another switching unit 1 . A plurality of pipes branched from one sub-high-pressure gas pipe 11 a connected to the high-pressure gas pipe 11 extending from the outdoor unit 2 are each connected to each switching mechanism 10 . That is, the pipes leading from each switching mechanism 10 to each high pressure gas pipe 11 are connected to each other by one secondary high pressure gas pipe 11a.

One end of the low-pressure gas pipe 12 is connected to the outdoor unit 2 and the other end is connected to one end of a sub-low-pressure gas pipe 12 a provided with a branch pipe connecting to each switching mechanism 10 inside the switching unit 1 . The sub-low-pressure gas pipe 12 a is a pipe arranged inside the switching unit 1 . When the number of indoor units 3 is more than 12, the other end of the sub-low-pressure gas pipe 12a is connected to the switching mechanism 10 of another switching unit 1 . On the other hand, when the number of indoor units 3 is 12 or less, the other end of the sub-low-pressure gas pipe 12a is closed without being connected to the switching mechanism 10 of another switching unit 1 . Each of a plurality of pipes branched from one sub-low-pressure gas pipe 12 a connected to the low-pressure gas pipe 12 extending from the outdoor unit 2 is connected to each switching mechanism 10 .

One end of the liquid pipe 13 is connected to the outdoor unit 2 , and the other end is connected to one end of a secondary liquid pipe 13 a provided with a branch pipe connecting to each switching mechanism 10 inside the switching unit 1 . The secondary liquid pipe 13 a is a pipe arranged inside the switching unit 1 . When the number of indoor units 3 is more than 12, the other end of the sub-liquid pipe 13a is connected to the switching mechanism 10 of another switching unit 1 . On the other hand, when the number of indoor units 3 is 12 or less, the other end of the sub-liquid pipe 13a is closed without being connected to the switching mechanism 10 of the other switching unit 1 . A plurality of pipes branched from one sub-liquid pipe 13 a connected to the liquid pipe 13 extending from the outdoor unit 2 are connected to each switching mechanism 10 .

By branching the secondary high-pressure gas pipe 11a, the secondary low-pressure gas pipe 12a, and the secondary liquid pipe 13a inside the switching unit 1 and connecting them to a plurality of switching mechanisms 10, a plurality of switching mechanisms 10 are connected to the outdoor unit 2. are connected in parallel. By connecting different indoor units 3 to each switching mechanism 10, the outdoor unit 2 and a plurality of indoor units 3 are connected via the switching unit 1, and the operation of the switching unit 1 causes the refrigerant in each indoor unit 3 to The direction of flow of the air changes, and each indoor unit 3 can individually perform the heating operation and the cooling operation.

<Configuration of outdoor unit>
The outdoor unit 2 is arranged outdoors of a building such as an apartment building. The outdoor unit 2 has an outdoor heat exchanger 21 , a compressor 22 and a four-way valve 23 . Furthermore, the outdoor unit 2 is connected to the switching unit 1 by a high-pressure gas pipe 11, a low-pressure gas pipe 12, and a liquid pipe 13, which serve as coolant flow paths.

The outdoor heat exchanger 21 is connected to the four-way valve 23 on one side of the refrigerant flow path and to the liquid pipe 13 on the other side. The outdoor heat exchanger 21 operates either as a condenser or an evaporator. When the outdoor heat exchanger 21 functions as a condenser, the four-way valve 23 is switched so that the discharge side of the compressor 22 and the outdoor heat exchanger 21 are communicated with each other. The refrigerant flows into the outdoor heat exchanger 21 , exchanges heat with outside air taken into the outdoor unit 2 by rotation of an outdoor fan (not shown), condenses, and flows out to the liquid pipe 13 .

When the outdoor heat exchanger 21 operates as an evaporator, the four-way valve 23 is switched so that the inflow side of the compressor 22 and the outdoor heat exchanger 21 are communicated, whereby the gas-liquid two-phase refrigerant is released from the liquid pipe 13. It flows into the outdoor heat exchanger 21 , exchanges heat with outside air taken into the outdoor unit 2 by rotation of an outdoor fan (not shown), evaporates, and flows out toward the compressor 22 . When the proportion of refrigerant used in heating operation in all indoor units 3 is greater than the proportion of refrigerant used in cooling operation, outdoor heat exchanger 21 functions as an evaporator. Conversely, when the proportion of refrigerant used in cooling operation in all indoor units 3 is greater than the proportion of refrigerant used in heating operation, outdoor heat exchanger 21 functions as a condenser.

The compressor 22 is a variable capacity compressor that can vary its operating capacity by being driven by a motor (not shown) whose rotation speed is controlled by an inverter. The compressor 22 has a suction side connected to the low pressure gas pipe 12 and a discharge side connected to the high pressure gas pipe 11 . The high-pressure gas pipe 11, one end of which is connected to the compressor 22, is branched at the other end inside the outdoor unit 2, one branch is connected to the sub-high-pressure gas pipe 11a of the switching unit 1, and the other branch is a four-way valve. 23. The low-pressure gas pipe 12, one end of which is connected to the compressor 22, branches off at the other end within the outdoor unit 2. One of the branches is connected to the secondary high-pressure gas pipe 11a of the switching unit 1, and the other branch It is connected to valve 23 . The compressor 22 compresses the low-pressure refrigerant flowing from the low-pressure gas pipe 12 into a high-pressure refrigerant and discharges it to the high-pressure gas pipe 11 .

The four-way valve 23 is a valve for switching the direction of flow of the refrigerant, and as shown in FIG. 1, has four ports a, b, c, and d. The four-way valve 23 has a port a connected to the low-pressure gas pipe 12 , a port b connected to the outdoor unit heat exchanger 21 , and a port c connected to the high-pressure gas pipe 11 . Also port d is closed. As indicated by the solid line in FIG. 1 , the port b and the port c of the four-way valve 23 are switched to communicate and the port a and the port d are switched to communicate, so that the port c of the four-way valve 23 discharges the compressor 22. side, port b is connected to the outdoor heat exchanger 21, and the outdoor heat exchanger 21 functions as a condenser. Further, as shown by the dashed line in FIG. 1, the port a and the port b of the four-way valve 23 are switched to communicate and the port c and the port d are switched to communicate with each other, so that the port a of the four-way valve 23 is connected to the compressor 22, the port b is connected to the outdoor heat exchanger 21, and the outdoor heat exchanger 21 functions as an evaporator.

When the outdoor heat exchanger 21 operates as a condenser, the four-way valve 23 is closed so that the outdoor heat exchanger 21 is connected to the high-pressure gas pipe 11 and the branched path of the low-pressure gas pipe 12 is sealed. The connection state of each port is switched. Further, when the outdoor heat exchanger 21 operates as an evaporator, the four-way valve The connection state of each port of 23 is switched.

<Indoor unit configuration>
The 12 indoor units 3 are arranged indoors of a building such as an apartment building. The indoor unit 3 has an indoor heat exchanger 31 and an indoor expansion valve 32 . The indoor unit 3 is connected to the switching unit by an indoor unit side gas connection pipe 14 and an indoor unit side liquid pipe connection pipe 15 .

The indoor heat exchanger 31 has one end of a refrigerant channel connected to the indoor unit side gas connection pipe 14 and the other end connected to a pipe connected to the indoor expansion valve 32 . The indoor heat exchanger 31 functions as a condenser when the indoor unit 3 operates for heating. Also, the indoor heat exchanger 31 functions as an evaporator when the indoor unit 3 operates as a cooler.

When the indoor unit 3 performs heating operation, the corresponding switching mechanism 10 switches the auxiliary high-pressure gas pipe 11a and the indoor heat exchanger 21 to communicate with each other so that the indoor heat exchanger 31 functions as a condenser. Specifically, the high-pressure, high-temperature refrigerant flowing out of the outdoor unit 2 into the high-pressure gas pipe 11 flows into the indoor unit 3 via the switching mechanism 10 and the indoor-unit-side gas connection pipe 14 . The refrigerant that has flowed into the indoor unit 3 flows into the indoor heat exchanger 31 to exchange heat with the indoor air taken into the indoor unit 3 by the rotation of an indoor fan (not shown), and is condensed. As a result, the indoor air that is taken in is heated and released into the room to heat the room. The refrigerant that has flowed out of the indoor heat exchanger 31 is decompressed by the indoor expansion valve 32 and flows out to the indoor unit side liquid pipe connection pipe 15 .

When the indoor unit 3 performs a cooling operation, the corresponding switching mechanism 10 switches the sub-low pressure gas pipe 12a and the indoor heat exchanger 21 to communicate with each other so that the indoor heat exchanger 31 functions as an evaporator. . Specifically, the low-pressure, low-temperature refrigerant flowing out of the outdoor unit 2 into the liquid pipe 13 flows into the indoor unit 3 via the switching mechanism 10 and the indoor unit-side liquid pipe connecting pipe 15 . The refrigerant that has flowed into the indoor unit 3 flows into the indoor heat exchanger 31, exchanges heat with the indoor air taken into the indoor unit 3 by the rotation of an indoor fan (not shown), and evaporates. As a result, the indoor air that has been taken in is cooled and released into the room to cool the room. The refrigerant that has flowed out of the indoor heat exchanger 31 is discharged to the indoor unit side gas connection pipe 14 .

The indoor expansion valve 32 is arranged between the indoor heat exchanger 31 and the indoor unit liquid pipe 34 . The opening of the indoor expansion valve 32 is adjusted according to the required cooling capacity when the indoor heat exchanger 31 operates as an evaporator, and the required heating capacity is adjusted when the indoor heat exchanger 31 operates as a condenser. The opening is adjusted according to the ability.

<Configuration of switching unit>
Next, the switching unit 1 will be described in detail. FIG. 2 is a perspective view of the switching unit 1. FIG. The switching unit 1 has a body case 16 shown in FIG.

The body case 16 has a top surface 161 , a front surface 162 , a back surface 163 , a right side surface 164 , a left side surface 165 and a bottom surface 166 . In the following description, the front 162 side of the body case 16 is the "front" direction, the rear 163 side is the "rear" direction, the right side 164 side is the "right" direction, the left side 165 side is the "left" direction, and the top 161 side. is called the "up" direction, and the bottom 166 side is called the "down" direction. Here, it is assumed that the switching unit 1 is arranged in the ceiling or the like, and it is preferable that the main body case 16 is small in size. In particular, it is preferable that the dimension in the height direction is small, and the dimension in the height direction (the length in the vertical direction) of the main body case 16 is preferably 298 mm or less as an example, and is 298 mm in this embodiment.

A secondary high-pressure gas pipe 11a, a secondary low-pressure gas pipe 12a, and a secondary liquid pipe 13a, which are connected to the outdoor unit 2, are arranged to protrude from the left side surface 165 of the main body case 16 . The sub-high-pressure gas pipe 11a, the sub-low-pressure gas pipe 12a, and the sub-liquid pipe 13a are arranged so as to protrude from the right side surface 164 of the main body case 16, and the sub-high-pressure gas pipe 11a and the sub-low-pressure gas pipe 11a corresponding to the other switching unit 1 are provided. By connecting to each of the pipe 12a and the sub-liquid pipe 13a, the switching unit 1 can be added according to the number of the indoor units 3. FIG. If the switching unit 1 is not added, the secondary high-pressure gas pipe 11a, the secondary low-pressure gas pipe 12a, and the secondary liquid pipe 13a led out from the right side surface 164 are closed with lids (not shown). A plurality of indoor unit side gas connection pipes 14 and indoor unit side liquid pipe connection pipes 15 each connected to a different indoor unit 3 are arranged to protrude from the front surface 162 of the main body case 16 .

The secondary high-pressure gas pipe 11a, the secondary low-pressure gas pipe 12a, and the secondary liquid pipe 13a are arranged in the order of the secondary high-pressure gas pipe 11a, the secondary liquid pipe 13a, and the secondary low-pressure gas pipe 12a from the front surface 162 side toward the rear surface 163 of the main body case 16. line up. The respective pipe axes of the secondary high-pressure gas pipe 11a, the secondary low-pressure gas pipe 12a, and the secondary liquid pipe 13a extend in the lateral direction of the main body case 16. As shown in FIG.

The indoor-unit-side gas connection pipe 14 is arranged on the upper side inside the main body case 16 so that a part thereof protrudes from the front surface 162 . The indoor unit side gas connection pipe 14 is a refrigerant pipe between one end of the third refrigerant pipe 103 and the indoor unit gas pipe 33 . Also, the indoor unit side liquid pipe connecting pipe 15 is arranged on the lower side inside the main body case 16 so that a part thereof protrudes from the front surface 162 . The indoor unit side liquid pipe connecting pipe 15 is a refrigerant pipe between the sub liquid pipe 13 a and the indoor unit liquid pipe 34 . The indoor unit side gas connection pipe 14 and the indoor unit side liquid pipe connection pipe 15 are arranged to protrude forward from the front surface 162 of the main body case 16 . Twelve indoor-unit-side gas connecting pipes 14 and twelve indoor-unit-side liquid pipe connecting pipes 15 are arranged in the horizontal direction of the main body case 16 . The pipe axes of the indoor unit side gas connecting pipe 14 and the indoor unit side liquid pipe connecting pipe 15 extend in the front-rear direction of the main body case 16 . The indoor unit side gas connecting pipes 14 and the indoor unit side liquid pipe connecting pipes 15 are arranged in a vertical line, and 12 pairs are provided. A side liquid pipe connection pipe 15 is connected to each of the twelve indoor units 3 .

A secondary high-pressure gas pipe 11a connected to the high-pressure gas pipe 11, a secondary low-pressure gas pipe 12a connected to the low-pressure gas pipe 12, a secondary liquid pipe 13a connected to the liquid pipe 13, an indoor unit side gas connection pipe 14, and the indoor unit Each of the side liquid pipe connection pipes 15 is included in the switching mechanism 10 connected between the outdoor unit 2 and the indoor unit 3 .

Next, the configuration of the switching mechanism 10 partially accommodated inside the body case 16 will be specifically described with reference to FIGS. 3 and 4. FIG. FIG. 3 is a perspective view of the switching mechanism 10 mounted on the switching unit 1. FIG. 4 is a side view of a single switching mechanism 10. FIG. All twelve switching mechanisms 10 are housed in the body case 16 .

In the body case 16 according to this embodiment, twelve switching mechanisms 10 shown in FIG. 4 are arranged side by side as shown in FIG. In this manner, all twelve switching mechanisms 10 are housed in the body case 16 . Each switching mechanism 10 has a first refrigerant pipe 101, a second refrigerant pipe 102, a third refrigerant pipe 103 and a fourth refrigerant pipe 104, respectively, as shown in FIGS. Each switching mechanism 10 also has a first capillary tube 121 , a second capillary tube 122 and a third capillary tube 123 . Furthermore, the switching mechanism 10 has a first solenoid valve 111 , a second solenoid valve 112 , a third solenoid valve 113 and a fourth solenoid valve 114 . Also, the switching mechanism 10 is arranged between the liquid pipe 13 and the indoor unit side liquid pipe connecting pipe 15 .

The first refrigerant pipe 101 has one end connected to the secondary high-pressure gas pipe 11 a and the other end connected to the first electromagnetic valve 111 . The first refrigerant pipe 101 is a pipe between the joint pipe 130 and the secondary high-pressure gas pipe 11a. The first refrigerant pipes 101 of each switching mechanism 10 extend in the front-rear direction of the body case 16 and are arranged side by side in the left-right direction of the body case 16 .

When the indoor unit 3 performs a heating operation, high-temperature and high-pressure refrigerant flows into the first refrigerant pipe 101 from the secondary high-pressure gas pipe 11a. The refrigerant that has flowed into the first refrigerant pipe 101 flows through the first electromagnetic valve 111, which is opened during heating operation, to the second refrigerant pipe 102, which will be described later. Thus, the first refrigerant pipe 101 is a pipe through which a high-temperature and high-pressure refrigerant flows, and the state of the flowing refrigerant is a gas refrigerant. Pressure loss increases. When the pressure loss increases, the temperature of the refrigerant flowing to the indoor unit 3 decreases, and the heating capacity exhibited by the indoor unit 3 decreases. Therefore, the first refrigerant pipe 101 preferably has a diameter as large as possible in order to limit the pressure loss to such an extent that the heating performance of the indoor unit 3 is not affected. For example, a pipe having a diameter of 15 mm or more is used as the first refrigerant pipe 101 . In this embodiment, the diameter of the first refrigerant pipe 101 is 15.88 mm.

One end of the second refrigerant pipe 102 is connected to the first electromagnetic valve 111 via a joint pipe 138 , and the other end joins the third refrigerant pipe 103 to be described later and is connected to the indoor unit side gas connection pipe 14 . The second refrigerant pipe 102 is a pipe between the joining positions from the joint pipe 134 to the third refrigerant pipe 103 . The second refrigerant pipes 102 also extend in the front-rear direction of the body case 16 and are arranged side by side in the left-right direction of the body case 16 .

When the indoor unit 3 performs the heating operation, high-temperature and high-pressure refrigerant flows into the second refrigerant pipe 102 from the first electromagnetic valve 111 that is opened during the heating operation. Since the fourth solenoid valve 114 is closed during heating operation, the refrigerant that has flowed into the second refrigerant pipe 102 flows into the indoor unit side gas connection pipe 14 . Thus, the second refrigerant pipe 102 is a pipe through which the refrigerant sent to the indoor-unit-side gas connection pipe 14 flows. Since the pressure loss is proportional to the square of the flow velocity of the refrigerant, the flow velocity decreases when passing through the first solenoid valve 111 . Therefore, when the refrigerant leaves the second refrigerant pipe 102, the pressure loss received from the second refrigerant pipe 102 is reduced. Therefore, a pipe having a smaller diameter than the first refrigerant pipe 101 can be used as the second refrigerant pipe 102 . For example, a pipe with a diameter of 12 mm or more is used as the second refrigerant pipe 102 . In this embodiment, the diameter of the second refrigerant pipe 102 is 12.7 mm.

The third refrigerant pipe 103 joins the second refrigerant pipe 102 at an intermediate position. One end of the third refrigerant pipe 103 is connected to the indoor unit side gas connection pipe 14 , and the other end is connected to the fourth solenoid valve 114 . The third refrigerant pipe 103 is a pipe between the fourth solenoid valve 114 and the indoor unit gas connection pipe 14 . The third refrigerant pipes 103 also extend in the front-rear direction of the body case 16 and are arranged side by side in the left-right direction of the body case 16 .

A gas-liquid two-phase refrigerant flows into the third refrigerant pipe 103 from the indoor unit side gas connection pipe 14 when the indoor unit 3 performs cooling operation. Since the first electromagnetic valve 111 is closed, the refrigerant that has flowed into the third refrigerant pipe 103 flows through the fourth electromagnetic valve 114, which is open during cooling operation, into the sub-low-pressure gas pipe 12a. In this way, the refrigerant in the gas-liquid two-phase state flows through the third refrigerant pipe 103, and since the gas refrigerant is included, the pressure loss received from the third refrigerant pipe 103 is greater than when only the liquid refrigerant flows. . When the pressure loss increases, the amount of refrigerant flowing through the indoor unit 3 decreases, and the cooling capacity exhibited by the indoor unit 3 decreases. Therefore, it is preferable that the third refrigerant pipe 103 has a diameter as large as possible in order to keep the pressure loss at a level that does not affect the cooling performance of the indoor unit 3 . For example, a pipe with a diameter of 15 mm or more is used as the third refrigerant pipe 103 . In this embodiment, the diameter of the third refrigerant pipe 103 is 15.88 mm.

The fourth refrigerant pipe 104 has one end connected to the fourth electromagnetic valve 114 via a pipe 114C, and the other end connected to the auxiliary low-pressure gas pipe 12a. The fourth refrigerant pipe 104 is a pipe between the pipe 114C extending from the outflow port of the fourth solenoid valve 114 and the sub low-pressure gas pipe 12a. The fourth refrigerant pipes 104 also extend in the front-rear direction of the body case 16 and are arranged side by side in the left-right direction of the body case 16 .

In the fourth refrigerant pipe 104, when the indoor unit 3 performs the cooling operation, the refrigerant condensed in the indoor unit 3 into a gas-liquid two-phase state is supplied through the third refrigerant pipe 103 and the fourth solenoid valve 114. inflow. The refrigerant that has flowed into the fourth refrigerant pipe 104 flows to the secondary low-pressure gas pipe 12a. In this way, the fourth refrigerant pipe 104 is a pipe that sends out the refrigerant to the outdoor unit 2, and a pipe with a smaller diameter than the third refrigerant pipe 103 can be used. For example, a pipe with a diameter of 12 mm or more is used as the fourth refrigerant pipe 104 . In this embodiment, the diameter of the fourth refrigerant pipe 104 is 12.7 mm.

Here, the arrangement of the first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe 103, and the fourth refrigerant pipe 104 in the vertical direction and the horizontal direction will be described with reference to FIGS. 4 and 5. FIG. FIG. 5 is a top view of the two switching mechanisms 10. FIG. The first refrigerant pipe 101 is arranged near the upper surface 161 of the body case 16 .

The second refrigerant pipe 102 is arranged directly under the first refrigerant pipe 101 in parallel with the first refrigerant pipe 101 with a distance L1 equal to or greater than the diameter of the first refrigerant pipe 101 . For example, if the diameter of the first refrigerant pipe 101 is 15.88 mm, the distance L1 should be 16 mm or more. The direction from the first refrigerant pipe 101 to the second refrigerant pipe 102, that is, the vertical direction in the main body case 16 corresponds to an example of the "predetermined direction."

The third refrigerant pipe 103 is arranged below the second refrigerant pipe 102 with a distance L2 in the vertical direction from the second refrigerant pipe 102 as shown in FIG. 101 and the second refrigerant pipe 102 at a distance L7 in the left direction. That is, the second refrigerant pipe 102 and the third refrigerant pipe 103 are arranged obliquely with respect to the bottom surface 166, and the distance between the second refrigerant pipe 102 and the third refrigerant pipe 103 is (L2 ² +L7 ² ) ^{1 /2} . The third refrigerant pipe 103 is arranged apart from the second refrigerant pipe 102 by a distance equal to or greater than the diameter of the third refrigerant pipe 103 . For example, if the diameter of the third refrigerant pipe 103 is 15.88 mm, the distance between the second refrigerant pipe 102 and the third refrigerant pipe 103 may be 16 mm or more, which is (L2 ² +L7 ² ) ¹ described above. It is sufficient if the distance obtained by ^/2 is 16 mm or more.

The fourth refrigerant pipe 104 is arranged directly under the third refrigerant pipe 103 in parallel with a distance L3 equal to or greater than the diameter of the third refrigerant pipe 103 . For example, if the diameter of the third refrigerant pipe 103 is 15.88 mm, the distance L3 should be 16 mm or more. That is, the first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe 103, and the fourth refrigerant pipe 104 are located at different positions in the left-right direction and the front-rear direction, but the direction from the top surface 163 to the bottom surface 166 ( The first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe 103, and the fourth refrigerant pipe 104 are arranged side by side in this order in the extending direction (to be described later).

Furthermore, in the piping where the second refrigerant pipe 102 and the third refrigerant pipe 103 join and connect to the indoor unit side gas connecting pipe 14, as a requirement for brazing, as shown in FIG. 4, the indoor unit side gas connecting pipe 14 and the indoor unit side liquid pipe connecting pipe 15 is preferably a certain distance or more as a distance for brazing. For example, in this embodiment, the distance L4 between the indoor unit side gas connecting pipe 14 and the indoor unit side liquid connecting pipe 15 is 105 mm or more. This distance L4 corresponds to an example of the "second predetermined distance".

FIG. 6 is a front view of the switching mechanism 10. FIG. In order to secure the distance L4, as shown in FIG. It is bent upward by bending away from the tube 15 .

Here, as shown in FIGS. 4 and 6, a straight portion 301 having a length L6 that is about twice the diameter of the third refrigerant pipe 103 is present as a gripping allowance for the bending work applied to the third refrigerant pipe 103. is preferred. The straight portion 301 is present in the third refrigerant pipe 103 between the junction with the second refrigerant pipe 102 and the connecting portion with the indoor unit gas connection pipe 14 . That is, in order to bend the third refrigerant pipe 103, a straight portion 301 having a length L6 equal to or longer than the grip margin required in the bending shown in FIG. 4 is formed in the third refrigerant pipe 103. FIG. For example, when the diameter of the third refrigerant pipe 103 is 15.88 mm, the length L6 is approximately 30 mm. By grasping the position corresponding to this straight portion 301 in the third refrigerant pipe 103 before bending and bending the third refrigerant pipe 103, the straight portion 301 is formed after bending.

Due to this bending, as shown in FIG. 4, the pipe 121a connecting the first capillary tube 121 and the secondary high-pressure gas pipe 11a approaches the third refrigerant pipe 103, and the distance L5 is shortened. Here, the distance L5 between the pipe 121a and the third refrigerant pipe 103 should be 25 mm or more in consideration of variations in clearance in order to avoid contact in the work process before being covered with the foamed heat insulating material. preferable. Therefore, as shown in FIG. 6, the third refrigerant pipe 103 is bent upward and also bent rightward. Thereby, the straight portion 301 is inclined with respect to a plane that is perpendicular to the bottom surface 166 and includes the fourth refrigerant pipe 104 .

By bending the third refrigerant pipe 103 as described above, the distance L4 between the indoor unit side gas connecting pipe 14 and the indoor unit side liquid pipe connecting pipe 15 is secured to satisfy the requirements required at the time of brazing, In addition, the vertical height of the switching unit 1 can be kept small while ensuring a distance L5 of 25 mm or more between the indoor-unit-side gas connecting pipe 14 and the pipe 121a extending from the secondary high-pressure gas pipe 11a.

The first electromagnetic valve 111 is an on-off valve (two-way valve). As described above, the first solenoid valve 111 is opened during the heating operation, and by opening the first solenoid valve 111, the auxiliary high-pressure gas pipe 11a and the indoor unit side gas connection pipe 14 are connected to the first refrigerant pipe. 101 and the second refrigerant pipe 102 . At this time, the side of the first solenoid valve 111 connected to the first refrigerant pipe 101 serves as a refrigerant inflow port, and the side connected to the second refrigerant pipe 102 serves as a refrigerant outflow port.

The first solenoid valve 111 is a pilot-type solenoid valve that operates a valve body (not shown) by utilizing the pressure difference between the pressure on the inlet side and the pressure on the outlet side of the first solenoid valve 111 . A feature of the pilot-type solenoid valve is that the valve body is operated using the pressure difference, so it is possible to increase the valve diameter compared to a direct-acting solenoid valve that operates only by electromagnetic force. The refrigerant passage in which the first solenoid valve 111 is provided is a passage through which a high-pressure refrigerant flows during heating operation. The valve has a small diameter, and it may not be possible to secure the required heating capacity. Therefore, a pilot-type first solenoid valve 111 that utilizes the pressure difference between the pressure on the inlet side and the pressure on the outlet side is used in the flow path through which the high-pressure refrigerant flows during the heating operation.

Specifically, as shown in FIGS. 3 and 5, the first electromagnetic valve 111 has a valve body 111A and a coil portion 111B. Also, here, the pipe on the side connected to the first refrigerant pipe 101 of the first solenoid valve 111 is assumed to be a pipe 111C. A pipe 111D extends downward from the outflow port of the first electromagnetic valve 111. As shown in FIG. Furthermore, a joint pipe 130 is brazed in advance to the pipe 111C of the first electromagnetic valve 111 to which the first refrigerant pipe 101 is connected. A joint pipe 134 is brazed to the pipe 111D.

The valve body 111A has a pilot valve that switches between communication and blocking of the flow path that connects the secondary high-pressure gas pipe 11a and the indoor unit side gas connection pipe 14 . The coil portion 111B is provided to operate the pilot valve provided on the valve main body 111A by electromagnetic force. When the pilot valve is operated by the electromagnetic force generated by the coil portion 111B, the pressure at the upper portion of the valve body (not shown) rises and becomes higher than the pressure at the lower portion of the valve body, thereby operating the valve body.

A joint pipe 130 is previously connected to the pipe 111C of the valve body 111A by brazing before the first solenoid valve 111 of the switching mechanism 10 is assembled. FIG. 7 is a diagram for explaining brazing of the joint pipe 130 in the first solenoid valve 111. FIG. When the joint pipe 130 is brazed to the pipe 111C extending from the valve body 111A, as shown in FIG. placed so that Then, the joint pipe 130 is fitted to the pipe 111C placed in the state shown in FIG. 7, and brazing is performed at the brazing point P1. During this brazing, water is sprayed on the valve main body 111A in order to keep the valve main body 111A below the heat-resistant temperature. In the state of FIG. 7, the valve main body 111A and the brazing portion P1 of the joint pipe 130 are arranged side by side. Therefore, even if water is sprinkled on the valve body 111A, water does not drip from the valve body 111A, and it is possible to prevent water from splashing on the brazing location P1. Brazing is possible at the attachment point P1.

FIG. 8 is a perspective view for explaining brazing of the first solenoid valve 111 and the secondary high-pressure gas pipe 11a. In the assembly work of the switching mechanism 10, the joint pipe 130 is pre-assembled to the pipe 111C in a state where the first refrigerant pipe 101 is positioned below the pipe 111C connected to the valve body 111A as shown in FIG. and the first refrigerant pipe 101 are brazed at the brazing point P2. As a result, the first refrigerant pipe 101 and the pipe 111C connected to the valve main body 111A are connected. The joint piping 130 can increase the distance between the valve body 111A and the brazing location P2. Here, when the secondary high-pressure gas pipe 11a and the joint pipe 130 are brazed, if water is sprayed on the valve body 111A, the water will flow to the brazing location P2, making brazing difficult. In contrast, in this embodiment, by covering the valve body 111A with a wet cloth, the valve body 111A can be kept below the heat-resistant temperature, and the valve body 111A is prevented from being splashed with water. Therefore, the brazing of the brazing portion P2 can be reliably performed. In addition, the second refrigerant pipe 102 is brazed to the pipe 111D extending from the valve body 111A. In this case also, there is a distance between the brazed part and the valve body 111A, so the wet cloth protects the valve body 111A. can do.

Returning to FIG. 4, the description continues. The second electromagnetic valve 112 is also an on-off valve (two-way valve). One end of the second solenoid valve 112 is connected to the first refrigerant pipe 101 . The other end of the second solenoid valve 112 is branched so as to be connected to the indoor unit side gas connection pipe 14 and the third solenoid valve 113 . The second solenoid valve 112 and the indoor unit gas connection pipe 14 are connected via the third capillary tube 123 and the third refrigerant pipe 103 . A second capillary tube 122 is connected in parallel to the second electromagnetic valve 112 . Specifically, one end of the second capillary tube 122 is connected to the first refrigerant pipe 101, and the other end is connected to the location where the second solenoid valve 112 and the third solenoid valve 113 are connected. By opening the second solenoid valve 112, the pressure difference between the pressure at the inlet and the pressure at the outlet of the first solenoid valve 111 can be reduced (hereinafter referred to as "pressure equalization"). Since the flow path in which the second solenoid valve 112 is provided has a smaller pressure difference between the pressure on the inlet side and the pressure on the outlet side of the solenoid valve compared to the first refrigerant pipe 101, the second solenoid provided in this flow path The valve 112 is a direct-acting solenoid valve whose valve body operates only by electromagnetic force.

The second solenoid valve 112 has a valve body 112A and a coil portion 112B. The valve main body 112A has a valve body (not shown) that switches communication and blocking of the flow path in which the second solenoid valve 112 is provided. The coil portion 112B is provided to operate the valve body provided in the valve main body 112A by electromagnetic force. The electromagnetic force generated by the coil portion 112B operates the valve body of the valve main body 112A.

The second solenoid valve 112 is opened before the first solenoid valve 111 is opened, thereby equalizing pressure between the inlet and the outlet of the first solenoid valve 111 . Here, when the first solenoid valve 111 is opened in a state where the pressure difference between the inlet and the outlet of the first solenoid valve 111 is large, the pressure difference causes the refrigerant to flow vigorously through the first solenoid valve 111. Refrigerant flow noise may occur. Therefore, if the second solenoid valve 112 is opened before the first solenoid valve 111 is opened, the pressure at the inlet and the outlet of the first solenoid valve 111 is equalized via the third capillary tube 123, and after the pressure equalization, the first By opening the electromagnetic valve 111, the refrigerant flow noise is suppressed.

The third electromagnetic valve 113 is also an on-off valve (two-way valve). One end of the third solenoid valve 113 is connected to the sub-low pressure gas pipe 12a. The other end of the third solenoid valve 113 branches so as to be connected to the second solenoid valve 112 and the indoor unit side gas connection pipe 14 . The third solenoid valve 113 and the indoor unit side gas connection pipe 14 are connected via the third capillary tube 123 and the third refrigerant pipe 103 .

By opening the third solenoid valve 113, the pressure at the inlet and the outlet of the fourth solenoid valve 114 can be equalized. Since the flow path in which the third solenoid valve 113 is provided has a smaller pressure difference between the pressure on the inlet side and the pressure on the outlet side of the solenoid valve compared to the first refrigerant pipe 101, the third solenoid provided in this flow path As the valve 113, a direct-acting solenoid valve whose valve body operates only by electromagnetic force is used.

The third electromagnetic valve 113 has a valve body 113A and a coil portion 113B. The valve main body 113A has a valve body (not shown) that switches communication and blocking of the flow path in which the third electromagnetic valve 113 is provided. The coil portion 113B is provided to operate the valve body provided in the valve main body 113A by electromagnetic force. The electromagnetic force generated by the coil portion 113B causes the valve body of the valve main body 113A to operate.

The third solenoid valve 113 is opened before the fourth solenoid valve 114 is opened to equalize the pressure at the inlet and the outlet of the fourth solenoid valve 114 . Here, when the fourth solenoid valve 114 is opened with a large pressure difference between the inlet and the outlet of the fourth solenoid valve 114, the pressure difference causes the refrigerant to flow vigorously through the fourth solenoid valve 114. Refrigerant flow noise may occur. Therefore, if the third solenoid valve 113 is opened before the fourth solenoid valve 114 is opened, the pressure at the inlet and the outlet of the fourth solenoid valve 114 is equalized through the third capillary tube 123, and after the pressure equalization, the fourth solenoid valve 114 is opened. By opening the solenoid valve 114, the refrigerant flow noise is suppressed.

The fourth solenoid valve 114 is also an on-off valve (two-way valve). As described above, the fourth solenoid valve 114 is opened during the cooling operation, and by opening the fourth solenoid valve 114, the flow path connecting the indoor unit side gas connection pipe 14 and the sub low pressure gas pipe 12a is opened. It is a valve that switches between communication and blocking. The fourth solenoid valve 114 has an inflow port on the side connected to the third refrigerant pipe 103 and a discharge port on the side connected to the fourth refrigerant pipe 104 .

The fourth solenoid valve 114 is a pilot type solenoid valve. The refrigerant passage in which the fourth solenoid valve 114 is provided is a passage through which a low-pressure refrigerant flows during cooling operation. The valve diameter is small, and the necessary cooling capacity may not be secured. Therefore, a pilot-type solenoid valve that utilizes the pressure difference between the pressure on the inlet side and the pressure on the outlet side is used in the flow path through which the low-pressure refrigerant flows during the cooling operation.

The fourth solenoid valve 114 has a valve body 114A and a coil portion 114B. Further, the fourth solenoid valve 114 has a pipe 114C and a pipe 114D extending from the valve main body 114A. The valve body 114A has a pilot valve that switches between communication and blocking of the flow path that connects the indoor-unit-side gas connection pipe 14 and the secondary low-pressure gas pipe 12a. The coil portion 114B is provided to operate the pilot valve provided on the valve main body 114A by electromagnetic force. When the pilot valve is operated by the electromagnetic force generated by the coil portion 114B, the pressure in the upper portion of the valve body (not shown) rises and becomes higher than the pressure in the lower portion of the valve body, and the valve body operates.

The fourth solenoid valve 114 is opened when the indoor unit 3 operates as a cooler, and the indoor unit side gas connection pipe 14 and the sub low-pressure gas pipe 12a communicate through the third refrigerant pipe 103 and the fourth refrigerant pipe 104. do.

FIG. 9 is a perspective view showing a connection state of the sub-low-pressure gas pipe 12a. FIG. 10 is a perspective view of the secondary low-pressure gas pipe 12a. FIG. 11 is a side view of the secondary low-pressure gas pipe 12a. As shown in FIGS. 9 to 11, the sub-low pressure gas pipe 12a has a branch pipe 211A for connecting to the fourth refrigerant pipe 104 and a branch pipe 211B connected to the third solenoid valve 113. As shown in FIGS.

Specifically, the auxiliary low-pressure gas pipe 12a is provided with holes for connecting the branch pipes 211A and 211B, and these holes are subjected to burring. In the burring process, in order to braze the branch pipes 211A and 211B to the sub-low pressure gas pipe 12a, the periphery of the hole drilled at a predetermined position in the sub-low-pressure gas pipe 12a is oriented in a direction away from the sub-low-pressure gas pipe 12a. This is the process of pulling out In burring, the processing equipment is placed near the hole during processing. Therefore, it is necessary to provide a work area for burring processing between the holes, and for example, it is preferable to provide a distance of 60 mm or more between the holes. As a result, a distance L201 required for burring is provided between the branch pipes 211A. Similarly, a distance L202 required for burring is provided between the branch pipes 211B.

Furthermore, when connecting the branch pipe 211A formed in the sub-low pressure gas pipe 12a and the fourth refrigerant pipe 104, and when connecting the branch pipe 211B and the third solenoid valve 113 with the refrigerant pipe, at each connection part Brazing work is required, but if the connecting portions are close to each other, the brazing applied to the adjacent connecting portions will melt, causing the problem of leakage of coolant from the connecting portions. Therefore, it is necessary to secure a distance between the connecting portions that does not affect the adjacent connecting portions (hereinafter referred to as a brazing distance). For example, the distance between brazes is 30 mm.

Therefore, the branch pipes 211A and 211B of the sub-low-pressure gas pipe 12a according to this embodiment are not connected to the same location on the circumference of the sub-low-pressure gas pipe 12a as shown in FIGS. . Specifically, as shown in FIGS. 10 and 11, the branch pipes 211A are arranged in a line in the pipe axial direction, and are arranged in holes opened on the back side of the main body case 1 on the circumference of the sub low-pressure gas pipe 12a. Connected. On the other hand, the branch pipe 211B is arranged at a position shifted by an angle θ in the circumferential direction from the position of the branch pipe 211A and at a position not aligned with the branch pipe 211A when viewed from the pipe axial direction. They are arranged in a row in the pipe axial direction and connected to the upwardly opening holes on the circumference of the gas pipe 12a.

Here, the angle θ is determined so that the distance between the branch pipes 211A and 211B is greater than the brazing distance. For example, when the brazing distance is 30 mm in this embodiment, if the angle θ is 90 degrees, in the sub low-pressure gas pipe 12a in this embodiment, the brazing distance between the branch pipe 211A and the branch pipe 211B is 30 mm can be secured. The angle θ may be an angle other than 90 degrees as long as the brazing distance can be secured. In this way, by not connecting the branch pipes 211A and 211B of the sub-low-pressure gas pipe 12a to the same location on the circumference of the sub-low-pressure gas pipe 12a, all the branch pipes 211A and 211B are arranged in the pipe axial direction. Compared to the case of arranging them in a row, the dimension of the main body case 16 in the left-right direction can be reduced while securing the space for burring processing.

Here, the arrangement of the first solenoid valve 111, the second solenoid valve 112, the third solenoid valve 113, and the fourth solenoid valve 114 within the main body case 16 will be described. Each of the first solenoid valve 111, the second solenoid valve 112, the third solenoid valve 113, and the fourth solenoid valve 114 has a coil portion 111B, a coil portion 112B, a coil portion 113B, and a , the coil portion 1114 B is arranged to protrude from the rear surface 163 . This is to facilitate access to the coil portions 111B to 114B of the first solenoid valve 111, the second solenoid valve 112, the third solenoid valve 113, and the fourth solenoid valve 114 during maintenance.

12 is a rear view of the switching mechanism 10. FIG. As shown in FIG. 12, the first solenoid valve 111, the second solenoid valve 112, the third solenoid valve 113, and the fourth solenoid valve 114 are separated from each other by the coil portion 111B of the first solenoid valve 111 and the fourth solenoid valve 111 in the vertical direction. The coil portion 112B of the second electromagnetic valve 112 and the coil portion 112B of the third electromagnetic valve 113 are positioned between the coil portion 113B of the second electromagnetic valve 114 and the coil portion 113B of the third electromagnetic valve 114 . In FIG. 12, the valve body 112A of the second solenoid valve 112 and the valve body 113A of the third solenoid valve 113 are not shown. A third electromagnetic valve 113 refers to the portion of . Further, in the description here, the coil portion 111B may be simply called the first solenoid valve 111 and the coil portion 111B may be called the second solenoid valve 112 in some cases.

As described above, the first solenoid valve 111 is connected to the first refrigerant pipe 101 and arranged near the upper surface 161 of the body case 16 . A pipe 111D extending from the outflow port of the first electromagnetic valve 111 and connected to the second refrigerant pipe 102 is arranged to extend downward from the valve main body 111A. Also, the fourth solenoid valve 114 is connected to the fourth refrigerant pipe 104 and arranged near the bottom surface 166 of the main body case 16 . A pipe 114C extending from the outflow port of the fourth electromagnetic valve 114 and connected to the fourth refrigerant pipe 104 is arranged to extend downward from the valve main body 114A.

Here, the first solenoid valve 111 and the fourth solenoid valve 114 are pilot type solenoid valves. In the first solenoid valve 111, the pipe 111D connected to the valve main body 111A and the pipe 130 face different directions. Similarly, in the fourth solenoid valve 114, the pipe 114C and the pipe 114D connected to the valve main body 114A face different directions. On the other hand, the second solenoid valve 112 and the third solenoid valve 113 are direct acting solenoid valves. In the second solenoid valve 112, the pipes 136 and 137 connected to the valve main body 112A face the same direction. Similarly, in the third solenoid valve 113, the pipes 138 and 139 connected to the valve main body 113A face the same direction. Therefore, the second solenoid valve 112 and the third solenoid valve 113 have a greater degree of freedom in arrangement than the first solenoid valve 111 and the fourth solenoid valve 114 .

When the first solenoid valve 111, the second solenoid valve 112, the third solenoid valve 113, and the fourth solenoid valve 114 are arranged to face the rear surface 163, the pipe 111D is connected from the outflow port of the first solenoid valve 111. It extends downward, and is arranged so that the pipe 114C extends downward from the outflow port of the fourth solenoid valve 114 .

Here, the connecting portion of the outflow port of the first solenoid valve 111 needs to have a length of 16 mm from the lower end of the valve main body 111A in consideration of heat conduction during brazing to the valve main body 11A. In addition, it is necessary to secure 32 mm as the dimension of the pipe 111D required for bending the second refrigerant pipe 102 connected to the outlet. Therefore, it is preferable to secure a space of 48 mm or more as a distance L8 from the lower end of the valve body 111A of the first solenoid valve 111, ie, the upper end of the pipe 111D, as a space for arranging the pipe 111D.

The second solenoid valve 112 is located between the first solenoid valve 111 and the third solenoid valve 113 in the vertical direction, and is shifted to the left so as not to interfere with the pipe 111D extending from the outflow port of the first solenoid valve 111. placed in Further, the second solenoid valve 112 is arranged so as not to interfere with the pipe 111D extending from the outflow port of the first solenoid valve 111 of the switching mechanism 10 on the left side. In this case, when the switching mechanism 10 is viewed from above, the coil portion 112B of the second electromagnetic valve 112 overlaps the coil portion 111B of the first electromagnetic valve 111, and about half of the lateral width of the coil portion 112B is the coil portion 111B. It is in a state of protruding from the In addition, the first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe 103 connected to the first solenoid valve 111, the second solenoid valve 112, the third solenoid valve 113, and the fourth solenoid valve 114, The fourth refrigerant pipe 104 extends straight in the front-rear direction, and the part that is bent in the middle is between the vertical plane containing the first electromagnetic valve 111 and the vertical plane containing the second electromagnetic valve 112. bent towards. Also, the diameters of the first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe 103, and the fourth refrigerant pipe 104 are smaller than those of the coil portions 111B to 114B. That is, the left and right width of one set of switching mechanisms 10 can be suppressed to about 1.5 times the electromagnetic coil because about half of the left and right width of the coil portion 112B protrudes from the coil portion 111B.

The third solenoid valve 113 is arranged below the first solenoid valve 111 . Specifically, the third solenoid valve 113 is arranged directly below the first solenoid valve 111 at a distance equal to or greater than the distance L8 from the connection port of the first solenoid valve 111 .

Also, the fourth solenoid valve 114 is arranged directly below the second solenoid valve 112 . The second solenoid valve 112 and the third solenoid valve 113 are direct-acting solenoid valves, and both of the two connection ports are provided so as to extend forward of the body case 16 . Since the second solenoid valve 112 does not need to secure a distance equivalent to the distance L8 provided in the pipe 111D portion of the first solenoid valve 111, the fourth solenoid valve can be arranged close to the second solenoid valve 112. The fourth solenoid valve 114 does not interfere with each connecting portion or the second refrigerant pipe 102 and the third refrigerant pipe 103 connected to each connecting portion.

As described above, the third solenoid valve 113 is arranged directly below the first solenoid valve 111 at a distance that does not interfere with the pipe 111D extending downward from the valve body 111A of the first solenoid valve 111 . In addition, the second solenoid valve 112 is arranged on the left side of the first solenoid valve 111 with a distance that does not interfere with the piping 111D extending downward from the valve main body 111A of the first solenoid valve 111 . Then, the fourth solenoid valve 114 is arranged directly below the second solenoid valve 112 . As a result, both the lateral and vertical dimensions of the switching mechanism 10 can be shortened. The horizontal and vertical dimensions can be reduced.

The second capillary tube 122 is arranged near the first refrigerant pipe 101 . Also, the second solenoid valve 112 is arranged above the third solenoid valve 113 . Therefore, the pipe 138 connecting the third solenoid valve 113 to the second capillary tube 122 and the second solenoid valve 112 extends upward from the third solenoid valve 113 . However, the third solenoid valve 113 is arranged directly below the first solenoid valve 111 and in the vicinity of the pipe 111D extending downward from the discharge port of the first solenoid valve 111 . Therefore, if the pipe 138 extending upward from the third solenoid valve 113 is extended in the normal direction of the bottom surface 166, it interferes with the pipe 111D extending downward from the discharge port of the first solenoid valve 111. avoid.

FIG. 13 is a rear view of the switching mechanism 10 with the coil portions of the solenoid valves removed. A pipe 138 extending upward from the third solenoid valve 113 is inclined upward and to the left from the normal direction of the bottom surface 166 as shown in FIG. 13 in consideration of interference with the pipe 111D. This avoids interference between the piping 111D extending downward from the discharge port of the first electromagnetic valve 111 and the piping extending upward from the third electromagnetic valve 113, thereby separating the first electromagnetic valve 111 and the third electromagnetic valve 113. can get closer.

The first capillary tube 121 is a decompression mechanism in which a thin pipe is spirally formed. The first capillary tube 121 is connected to the first refrigerant pipe 101 so as to bypass a check valve (not shown) provided in the first refrigerant pipe 101 . After installing the multi-room air conditioner including the switching unit 1, it is necessary to evacuate the inside of the refrigerant circuit before filling the refrigerant circuit with the refrigerant. At this time, the check valve prevents the evacuation. . Therefore, by providing the first capillary tube 121 so as to bypass the check valve as described above, the refrigerant circuit is evacuated via the first capillary tube 121. .

When the refrigerant passes through the first capillary tube 121, refrigerant flow noise is generated. Below, the refrigerant flow sound may be referred to as the refrigerant sound. In order to reduce refrigerant noise in the first capillary tube 121, butyl rubber is attached to the first capillary tube 121 before the switching mechanism group 100 including the twelve switching mechanisms 10 is housed in the main body case 16. The butyl rubber is attached so as to sandwich the first capillary tube 121 with one sheet. This first capillary tube 121 corresponds to an example of the "third decompression mechanism". The butyl rubber attached to the first capillary tube 121 corresponds to an example of the "third noise reduction member".

14A and 14B are diagrams showing the mounting state of the switching mechanism group 100 when the butyl rubber is pasted. As shown in FIG. 14, the operation of attaching the butyl rubber is performed by connecting the first solenoid valve 111, the second solenoid valve 112, and the fourth solenoid valve 114 in the switching mechanism group 100 to the indoor unit side gas connection pipe 14 and the indoor unit side liquid connection pipe. It is done in a state where it is placed above 15. When sticking butyl rubber, it is preferable that the first capillary tube 121 is arranged at a location that is easily accessible from directions D1 and D2 in FIG. In addition, in order to perform the butyl rubber pasting work, it is preferable to provide a gap of a size, for example, 20 mm or more, on both sides of the first capillary tube 121 so that an operator's fingers can be easily inserted.

Here, the first capillary tube 121 is located between the first solenoid valve 111 and the secondary high-pressure gas pipe 11a in the front-rear direction of the body case 16, and is located on the rightmost side in the left-right direction of the body case 16. Between the first refrigerant pipes 101, in the vertical direction of the main body case 16, it is arranged at a position near the first refrigerant pipe 101 between the first refrigerant pipe 101 and the second refrigerant pipe 102, and is substantially the same height as the first refrigerant pipe 101. It is arranged so that it becomes

The first capillary tube 121 is preferably positioned as close to the outside of the switching mechanism 10 as possible in order to facilitate the attachment operation of the butyl rubber by the operator. Therefore, since the first capillary tube 121 is connected to the first refrigerant pipe 101, in order to make the connecting pipe between the first capillary tube 121 and the first refrigerant pipe 101 as short as possible, the first capillary tube 121 is It is arranged in the vicinity of the first refrigerant pipe 101 which is easily accessible from the D1 direction of .

Also, the first capillary tube 121 is arranged so that the plane formed by the circumference of the spiral tube is substantially parallel to the right side 164 or the left side 165 of the body case 16 . FIG. 15 is a D1 arrow view of the switching mechanism group 100 in FIG. The first capillary tube 121, as shown in FIG. are arranged so that the distance L12 between them is both 20 mm or more. Here, left and right in FIG. 5 are opposite to left and right in the switching unit 1 .

The second capillary tube 122 is a decompression mechanism having a thin spiral pipe. As described above, the second capillary tube 122 has one end connected to the first refrigerant pipe 101 and the other end connected to the point where the second solenoid valve 112 and the third solenoid valve 113 are connected.

Similarly to the first capillary tube 121, the second capillary tube 122 also generates refrigerant noise when the refrigerant flows. Therefore, in order to reduce the refrigerant noise in the second capillary tube 122, butyl rubber is attached to the second capillary tube 122 before the switching mechanism group 100 including the 12 switching mechanisms 10 is housed in the main body case 16. be done. The butyl rubber is attached so as to sandwich the second capillary tube 122 with one sheet. This second capillary tube 122 corresponds to an example of the "first decompression mechanism". The butyl rubber attached to the second capillary tube 122 corresponds to an example of the "second silencer".

The second capillary tube 122 is also preferably positioned as close to the outside of the switching mechanism 10 as possible, in order to facilitate the worker's attachment work when attaching the butyl rubber. The second capillary tubes 122 are arranged between the first solenoid valve 111 and the sub-high-pressure gas pipe 11a in the longitudinal direction of the main body case 16, and are located on the rightmost side in the lateral direction of the main body case 16. Between 101, in the vertical direction of the main body case 16, it is arranged at a position closer to the first refrigerant pipe 101 between the first refrigerant pipe 101 and the second refrigerant pipe 102, and is approximately the same height as the first refrigerant pipe 101. are arranged so that This makes it easier for the operator to access the second capillary tube 122 from the D1 direction in FIG. Here, the second capillary tube 122 is arranged closer to the rear surface 163 of the main body case 16 than the first capillary tube 121 is.

Further, the second capillary tube 122 is arranged so that the plane formed by the circumference of the spiral tube is substantially parallel to the right side 164 or the left side 165 of the body case 16 . 15, the second capillary tube 122 has a distance L21 between the right first refrigerant pipe 101 of the second capillary tube 122 and a distance L21 between the second capillary tube 122 and the first refrigerant pipe 101 on the left side of the second capillary tube 122. The distance L22 between 101 and 101 is a dimension that allows the operator's fingers to be easily inserted, for example, 20 mm or more.

The third capillary tube 123 is a decompression mechanism having a thin spiral pipe. As described above, the third capillary tube 123 has one end connected to the point where the second solenoid valve 112 and the third solenoid valve 113 are connected, and the other end connected to the indoor unit side gas connection pipe 14 . be.

Similarly to the first capillary tube 121 and the second capillary tube 122, the third capillary tube 123 also generates refrigerant noise when the refrigerant flows. Therefore, in order to reduce the refrigerant noise in the third capillary tube 123, butyl rubber is attached to the third capillary tube 123 before the switching mechanism group 100 including the twelve switching mechanisms 10 is housed in the main body case 16. be done. The butyl rubber is attached so as to sandwich the third capillary tube 123 with one sheet. This third capillary tube 123 corresponds to an example of the "second decompression mechanism". The butyl rubber attached to the third capillary tube 123 corresponds to an example of the "second silencer".

The third capillary tube 123 is also preferably positioned as close to the outside of the switching mechanism 10 as possible in order to facilitate the attachment work of the operator during the attachment work of the butyl rubber. Therefore, since one end of the third capillary tube 123 is connected to the third refrigerant pipe 103 and the other end is connected to the third solenoid valve 113, the third capillary tube 123, the third refrigerant pipe 103, and the third solenoid valve 113 14. In order to minimize the connection piping with the third capillary tube 123, the third capillary tube 123 is arranged in the vicinity of the fourth refrigerant piping 104 and the third refrigerant piping 103, which are easily accessible from the D2 direction in FIG. The third capillary tubes 123 are located between the sub-liquid pipe 13a and the sub-low-pressure gas pipe 12a in the longitudinal direction of the main body case 16, and are located on the rightmost side in the lateral direction of the main body case 16. In the vertical direction of the main body case 16, by arranging it at a position closer to the third refrigerant pipe 103 between the third refrigerant pipe 103 and the fourth refrigerant pipe 104, it becomes easier to access from the D2 direction in FIG.

Also, the third capillary tube 123 is arranged so that the plane formed by the circumference of the spiral tube is substantially parallel to the right side 164 or the left side 165 of the body case 16 . FIG. 16 is a view of the switching mechanism group 100 in FIG. 14 as viewed from arrow D2. As shown in FIG. 16, the third capillary tube 123 has a distance L31 between the third capillary tube 123 and the third refrigerant pipe 103 on the left side, and a distance L31 between the third capillary tube 123 and the third refrigerant pipe 103 on the right side. It is arranged so that the distance L32 between them is a dimension that allows the operator's fingers to be easily inserted, for example, 20 mm or more.

In this manner, the first capillary tube 121, the second capillary tube 122, and the third capillary tube 123 are arranged at positions that are easily accessible from the outside, thereby improving the workability of attaching the butyl rubber. The operator can easily access the first capillary tube 121, the second capillary tube 122, and the third capillary tube 123, and can reliably and easily attach the butyl rubber.

After the switching mechanism group 100 is housed in the body case 16, the body case 16 is filled with foamed heat insulating material by injecting the body case 16 with the foamed heat insulating material. As a result, the portions of the switching mechanism group 100 housed inside the main body case 16 (the portion protruding outside the indoor unit side gas connecting pipe 14, the portion protruding outside the indoor unit side liquid pipe connecting pipe 15, , and portions other than the coil portions 111B to 114B) are covered with the foamed heat insulating material, and dew condensation on the parts covered with the foamed heat insulating material in the switching mechanism group 100 can be prevented.

FIG. 17 is a plan view of the switching unit 1 viewed from above. The injection and filling of foam insulation will now be described with reference to FIG. The upper surface 161 of the main body case 16 is formed with a plurality of injection ports 601 for injecting the undiluted solution of the foamed heat insulating material before foaming. In this embodiment, the injection port 601 is provided in a region of the upper surface 161 close to the rear surface 163 of the switching unit 1 .

In this embodiment, a two-liquid simple foam rigid urethane foam obtained by mixing a liquid A mainly containing isocyanate and a liquid B mainly containing polyol is used as the foamed heat insulating material. The two-liquid simple foam rigid urethane foam is liquid immediately after the A liquid and the B liquid are mixed. The liquid immediately after mixing the A liquid and the B liquid is hereinafter referred to as "foaming undiluted liquid". Then, the mixed liquids A and B cause a chemical reaction, and after a lapse of a certain period of time, expand to form a foam.

The foaming stock solution injected from the injection port 601 begins to accumulate on the bottom surface 166 of the main body case 16 . FIG. 18 is a diagram showing a state in which the upper surface 161 of the main body case 16 is removed. As shown in FIG. 18 , the first refrigerant pipe 101 of the switching mechanism group 100 is arranged above the main body case 16 . Therefore, the foaming stock solution is injected from the first refrigerant pipe 101 side. Then, the foaming stock solution passes by the first refrigerant pipe 101 , the second refrigerant pipe 102 , the third refrigerant pipe 103 , and the fourth refrigerant pipe 104 in this order, and reaches the bottom surface 166 .

As described above, the first refrigerant pipe 101 and the second refrigerant pipe 102 are arranged in a row in the vertical direction. In addition, the third refrigerant pipe 103 and the fourth refrigerant pipe 104 are arranged in a row in the vertical direction and are arranged on the left side of the first refrigerant pipe 101 and the second refrigerant pipe 102, and the third refrigerant pipe 103 is arranged at a position lower than the second refrigerant pipe 102 . As a result, the foaming undiluted liquid injected from the plurality of inlets 601 of the main body case 16 is arranged vertically in the first refrigerant pipe 101 and the second refrigerant pipe 102, and vertically arranged in the third refrigerant pipe 103 and the fourth refrigerant. It flows between the piping 104 and drops to the bottom surface 166 .

When the foaming stock solution flows from the inlet 601 to the bottom surface 166, the first refrigerant pipe 101 and the second refrigerant pipe 102, and the third refrigerant pipe 103 and the fourth refrigerant pipe 104 are arranged vertically in a row. Because of this arrangement, the resistance when the foaming stock solution flows is reduced compared to the case where the pipes are arranged side by side in the left-right direction. Further, as described above, the first capillary tube 121 and the second capillary tube 122 arranged between the first refrigerant pipes 101 and the third capillary tube 123 arranged between the third refrigerant pipes 103 Each of is formed by a pipe thinner than the first refrigerant pipe 101 to the fourth refrigerant pipe 104, and the plane formed by the circumference of each spiral pipe of the first capillary tube 121 to the third capillary tube 123 is , are arranged substantially parallel to the right side 164 or the left side 165 of the body case 16 . Therefore, the resistance received from each of the first to third capillary tubes 121 to 123 when the undiluted foaming solution flows from the injection port 601 to the bottom surface 166 can be reduced.

The foaming stock solution injected from the injection port 601 and reaching the bottom surface 166 spreads and accumulates on the bottom surface 166 of the main body case 16 . Here, the first electromagnetic valve 111 , the second electromagnetic valve 112 , the third electromagnetic valve 113 and the fourth electromagnetic valve 114 are arranged near the rear surface 163 of the body case 16 . Furthermore, in the vicinity of the back surface 163 of the main body case 16, there are a first refrigerant pipe 101, a second refrigerant pipe 102, a third refrigerant pipe 103 and a fourth refrigerant pipe extending from the first electromagnetic valve 111 and the fourth electromagnetic valve 114, respectively. 104 exist. Therefore, on the rear surface 163 side of the main body case 16, the density of each member constituting the switching mechanism 10 is higher than on the front surface 162 side. The resistance received by the foaming undiluted solution flowing to is large.

In the switching unit 1 of the present embodiment, in consideration of the difference in density of each member constituting the switching mechanism 10 in the front-rear direction inside the main body case 16 , the injection port 601 in the upper surface 161 is located near the rear surface 163 . is provided in As a result, the foaming stock solution falls from above to the bottom surface 166 on the side of the back surface 163 where the density of the member is high, and flows from the back surface 163 side toward the front surface 162 side where the density of the member is low. Therefore, on the side of the rear surface 163 where the member is highly dense, the undiluted foaming solution injected from above is pushed downward and reaches the bottom surface 166, and the undiluted foaming solution that has reached the bottom surface 166 Since the members are less dense than the back surface 163 side, that is, the foaming concentrate flows to the front face 162 side where resistance from the members is small when flowing, the entire main body case 16 can be filled with the foaming concentrate without excess or deficiency.

In the undiluted foaming liquid injected into the main body case 16 from the injection port 601, the A liquid and the B liquid react with each other to foam. When the foaming stock solution foams, the volume increases from the bottom surface 166 of the main body case 16 toward the top surface 161 . In this case, the volume of the foamed undiluted solution increases in the upward direction. Therefore, the direction in which the volume of the foamed heat insulating material increases corresponds to the vertical direction of the switching unit. FIG. 19 is a diagram showing the process of foaming of the foamed heat insulating material when the distance between the refrigerant pipes is short. At this time, as shown in FIG. 19, when the interval between the refrigerant pipes having a diameter of 12 mm or more among the refrigerant pipes stored inside the main unit 16 is small, the foaming undiluted solution (hereinafter referred to as the foam insulation material 50) ) foams upward, it becomes difficult for foaming to progress between the refrigerant pipes, and there is a risk that foaming will be completed between the refrigerant pipes. When foaming is completed between the refrigerant pipes in this manner, there is a risk that a space P3 in which the foamed heat insulating material 50 does not exist may be generated from the side of each refrigerant pipe to the obliquely upward direction. There is a problem that each refrigerant pipe is exposed to the air and condensation occurs.

Therefore, in the switching unit 1 according to the present embodiment, among the refrigerant pipes stored inside the main unit 16, the first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe, which are refrigerant pipes having a diameter of 12 mm or more, Refrigerant pipe 103 and fourth refrigerant pipe 104 are set to a dimension that does not hinder foaming of foamed heat insulating material 50, for example, a dimension that is equal to or larger than the diameter of each refrigerant pipe. That is, the first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe 103, and the fourth refrigerant pipe 104 are arranged at different positions with respect to the direction in which the volume of the foam heat insulating material increases. As a result, when the foamed heat insulating material 50 expands upward between the refrigerant pipes, it reaches the space P3 before the foaming of the foamed heat insulating material 50 is completed, and the foamed heat insulating material surrounds each refrigerant pipe. 50, each refrigerant pipe is not exposed to the air and condensation occurs.

In addition, the switching unit 1 according to the present embodiment includes a first refrigerant pipe 101, a second refrigerant pipe 102, a third refrigerant pipe 103, and a fourth refrigerant pipe, each of which has a diameter of 12 mm or more and is relatively thick among the pipes of the switching mechanism 10. Since a gap larger than the diameter of the adjacent refrigerant pipes is provided between 104, the space between each refrigerant pipe is widened, and the expansion of the foam insulation material is not hindered. can be filled with foam insulation. As a result, it is possible to prevent the occurrence of a space such as the space P3 shown in FIG. Therefore, it is possible to suppress the occurrence of dew condensation on the main body case 16 .

FIG. 20 is a flow chart showing an overview of the manufacturing process of the switching unit 1. As shown in FIG. Next, an overview of the manufacturing process of the switching unit 1 will be described with reference to FIG.

A joint pipe 130 is brazed to the pipe 111</b>C of the first solenoid valve 111 . At this time, as described above, the first electromagnetic valve 111 is placed horizontally, and the brazing is performed while spraying water on the valve main body 111A with the brazing portion oriented horizontally (step S1). As a result, the first solenoid valve 111 in which the joint pipe 130 shown in FIG. 7 is connected to the valve body 111A is completed.

Here, both the first solenoid valve 111 and the fourth solenoid valve 114 are connected to refrigerant pipes having a large diameter. A first refrigerant pipe 101 and a second refrigerant pipe 102 are connected to the first electromagnetic valve 111 . Further, the third refrigerant pipe 103 and the fourth refrigerant pipe 104 are connected to the fourth electromagnetic valve 114 . In general, when a refrigerant pipe having a large diameter is brazed, the valve body is likely to be damaged due to the large amount of heat that accompanies the brazing. In this respect, since the pipes 114C and 135, which are the connecting portions in the fourth solenoid valve 114 according to this embodiment, are long, they are far from the brazed portion and the valve main body 114A is not damaged. On the other hand, since the pipes 111C and 111D, which are the connecting portions of the refrigerant pipes in the first electromagnetic valve 111, are short, there is a high possibility that the valve body 111A will be damaged by heat during brazing. Therefore, in the first electromagnetic valve 111, the joint pipe 130 is connected in advance to the pipe 111C, and the joint pipe 134 is connected in advance to the pipe 111D.

Next, the first electromagnetic valve 111 to fourth electromagnetic valve 114, the first refrigerant pipe 101 to fourth refrigerant pipe 104, and the first capillary tube 121 to third capillary tube 123 are brazed to each other ( step S2).

Here, a process of connecting the second refrigerant pipe 102 and the third refrigerant pipe 103 to the first solenoid valve 111 and the fourth solenoid valve 114 will be described with reference to FIGS. 21A and 21B. FIG. 21A is a plan view for explaining brazing of the second refrigerant pipe 102 and the third refrigerant pipe 103 to the first solenoid valve 111 and the fourth solenoid valve 114. FIG. 21B is a perspective view for explaining brazing of the second refrigerant pipe 102 and the third refrigerant pipe 103 to the first solenoid valve 111 and the fourth solenoid valve 114. FIG.

As shown in FIG. 21A, one end of the second refrigerant pipe 102 is brazed to the pipe 111D extending from the outlet of the first solenoid valve 111. As shown in FIG. At this time, in order to cool the first solenoid valve 111, the brazing is performed while the first solenoid valve 111 is covered with a wet cloth. A sufficient distance is secured from the valve main body 111A of the first solenoid valve 111 to the brazed portion, and the first solenoid valve 111 can be protected from heat by covering it with a wet cloth. Also, one end of the third refrigerant pipe 103 is brazed to one connecting portion of the fourth electromagnetic valve 114 . The other end of the second refrigerant pipe 102 is brazed to a portion of the third refrigerant pipe 103 closer to the fourth electromagnetic valve 114 than the straight portion 301 . The first solenoid valve 111, the fourth solenoid valve 114, the second refrigerant pipe 102, and the third refrigerant pipe 103 connected in this manner are combined into four, as shown in FIG. 21B. Here, a part of the switching mechanism group 100 is created by combining four switching mechanisms 10 into one group, and then three groups of four switching mechanisms 10 are connected to form the entire switching mechanism group 100 . Below, a set of four parts in which the second refrigerant pipe 102 and the third refrigerant pipe 103 are connected to the first solenoid valve 111 and the fourth solenoid valve 114 by brazing will be referred to as a "discharge suction valve sub group.

Next, the connection of the second capillary tube 122 and the third capillary tube 123 to the second solenoid valve 112 and the third solenoid valve 113 will be described with reference to FIGS. 22A and 22B. FIG. 22A is a plan view for explaining brazing of the second capillary tube 122 and the third capillary tube 123 to the second solenoid valve 112 and the third solenoid valve 113. FIG. 22B is a perspective view for explaining brazing of the second capillary tube 122 and the third capillary tube 123 to the second solenoid valve 112 and the third solenoid valve 113. FIG.

As shown in FIG. 22A, one end of the second capillary tube 122 and one end of the third capillary tube 123 are connected to the second electromagnetic valve 112 via refrigerant pipes. Similarly, one end of the second capillary tube 122 and one end of the third capillary tube 123 are also connected to the third electromagnetic valve 113 via refrigerant pipes. By connecting the second capillary tube 122 and the third capillary tube 123, the second capillary tube 122 is positioned near the first solenoid valve 111, and the third capillary tube 123 is connected to the fourth solenoid valve. 114. In this way, the second solenoid valve 112 and the third solenoid valve 113, to which the second capillary tube 122 and the third capillary tube 123 are connected, are grouped into four, as shown in FIG. 22B. Hereinafter, a set of four components in which the second solenoid valve 112 and the third solenoid valve 113 are connected to the second capillary tube 122 and the third capillary tube 123 will be referred to as a "pressurization/reduction valve subgroup". .

Returning to FIG. 20, the description of the assembly process is continued. Subsequent to step S2, the secondary high-pressure gas pipe 11a and the secondary low-pressure gas pipe 12a are assembled (step S3). Specifically, first, holes for connecting the branch pipes 211A and 211B are formed in the sub-low-pressure gas pipe 12a, and burring is performed on the peripheral edge of each hole. FIG. 23 is a perspective view of a low-pressure gas pipe set. As described above, the burred holes are provided at positions shifted by 90 degrees in the circumferential direction of the sub-low-pressure gas pipe 12a. As shown in FIG. 23, the branch pipes 211A and 211B are arranged in a row in the axial direction of the pipe, and the branch pipes 211A and 211B are circumferentially displaced from each other by 90 degrees. placed. Thus, a component in which four branch pipes 211A and 211B are connected to the sub-low-pressure gas pipe 12a of the low-pressure gas pipe 12 is called a "low-pressure gas pipe assembly".

FIG. 24 is a perspective view of a high-pressure gas pipe set. As shown in FIG. 24, a first refrigerant pipe 101 and a first capillary tube 121 are brazed to the secondary high-pressure gas pipe 11a. A component in which the four first refrigerant pipes 101 are connected to the secondary high-pressure gas pipe 11a of the high-pressure gas pipe 11 in this way is called a "high-pressure gas pipe set".

Returning to FIG. 20, the description of the assembly process is continued. Following step S3, the four switching mechanisms 10 are assembled into one set (hereinafter, the four switching mechanisms 10 are referred to as piping sub-sets 100A to 100C) (step S4). . FIG. 25 is a perspective view of an example of piping sub-sets 100A-100C. FIG. 25 shows the piping subgroup 100A arranged on the left side of the main body case 16. FIG. FIG. 26 is a diagram for explaining a state in which the piping subassembly 100A is assembled in a support base 200 made of sheet metal. Specifically, as shown in FIG. 26, a low-pressure gas pipe set, a discharge suction valve sub-set, a pressurization/reduction valve sub-set, and a high-pressure gas pipe set are mounted on a support base 200 and fixed while brazing each other. I do. At this time, for example, the joint pipe 130 connected to the pipe 111C of the first electromagnetic valve 111 and the first refrigerant pipe 101 are brazed. In the brazing of the joint pipe 130 and the first refrigerant pipe 101, since the joint pipe 130 is interposed, a wide distance between the brazed part and the valve body 111A can be secured, and the valve body 111A is covered with a wet cloth. Thereby, the temperature rise of the valve main body 11A can be suppressed.

FIG. 27 is an external perspective view of the piping subgroups 100A-100C. As shown in FIG. 27, in addition to the piping subgroup 100A, the main body case 16 has a piping subgroup 100B arranged in the center of the main body case 16, and a piping subgroup 100C arranged on the right side of the main body case 16. be done. A set including the piping sub-sets 100A to 100C is referred to as a "piping total set 100D". The process of step S4 completes the piping assembly 100D.

Returning to FIG. 20, the description of the assembly process is continued. Subsequent to step S4, housing assembly for housing the pipe assembly 100D in the main body case 16 is performed (step S5). Specifically, the housing is assembled by the following method.

FIG. 28A is a front perspective view of the piping assembly 100D to which the electromagnetic valve partition plate 171 is attached. FIG. 28B is a perspective view of the piping assembly 10D to which the electromagnetic valve partition plate 171 is attached, as seen from the rear side. First, as shown in FIGS. 28A and 28B, the electromagnetic valve partition plate 171 is attached to the rear surface 163 side of the piping assembly 100D.

FIG. 29 is a perspective view for explaining attachment of a butyl rubber sheet. As shown in FIG. 29, the pipe assembly 100D is placed on the workbench with the electromagnetic valve partition plate 171 facing downward. In the state of FIG. 29, the butyl rubber sheet 172 is attached to each of the first capillary tube 121 and the second capillary tube 122 from direction D1, and the butyl rubber sheet 172 is attached to the third capillary tube 123 from direction D2. The butyl rubber sheet 172 is affixed so as to sandwich the first capillary tube 121, the second capillary tube 122, and the third capillary tube 123 and cover them from both sides. The butyl rubber sheet 172 is omitted in the drawings used for the explanation of the following steps.

FIG. 30 is a diagram showing the process of mounting the pipe assembly 100D on the outer shell 602. As shown in FIG. As shown in FIG. 30, piping insulation 173 is attached to piping assembly 100D. Specifically, the pipe heat insulating material 173 is attached to a portion of the sub-high-pressure gas pipe 11a and the sub-low-pressure gas pipe 12a where they come into contact with the outer shell 602 . The outer body 602 is a member forming part of the body case 16 . Then, the pipe assembly 100</b>D to which the pipe heat insulating material 173 is attached is mounted on the outer shell 602 . A state in which the pipe assembly 100D is mounted on the outer shell 602 is shown in the bottommost drawing of FIG.

FIG. 31A is a perspective view of a state in which the indoor unit side liquid pipe connecting pipe 15 is connected to the secondary liquid pipe 13a. 31B is a perspective view of a state in which the pipe heat insulating material 131 and the pipe heat insulating material 151 are attached to the secondary liquid pipe 13a and the indoor unit side liquid pipe connecting pipe 15. FIG. In parallel with the process of mounting the pipe assembly 100D on the outer shell 602, the pipe heat insulating material 131 is attached to the secondary liquid pipe 13a shown in FIG. Attach it to the state shown in FIG. 31B. The pipe heat insulating material 131 and the pipe heat insulating material 151 are also attached to the parts of the secondary liquid pipe 13 a and the indoor unit side liquid pipe connection pipe 15 that come into contact with the outer shell 602 .

FIG. 32 is a perspective view of the switching mechanism group 100, the auxiliary liquid pipe 13a, and the indoor unit side liquid pipe connection pipe 15 mounted on the outer barrel 602. FIG. As shown in FIG. 32, the auxiliary liquid pipe 13a to which the indoor unit side liquid pipe connection pipe 15 is connected is mounted on the outer shell 602 on which the pipe assembly 100D is mounted. As a result, the switching mechanism group 100 is mounted on the outer barrel 602 .

Next, the lower outer case 603 is attached to the outer case 602 on which the switching mechanism group 100 is mounted. FIG. 33 is a perspective view of the switching unit 1 viewed from the bottom surface 166 side. 34 is a perspective view of the switching unit 1 viewed from the upper surface 161 side. As a result, as shown in FIGS. 33 and 34, a state in which the switching mechanism group 100 is housed in the body case 16 is completed.

The foaming stock solution is injected from the injection port 601 provided on the upper surface 161 into the switching unit 1 assembled as described above. The undiluted foaming solution injected into the body case 167 accumulates and spreads at the bottom of the body case 16 as described above. The material is filled without gaps.

Returning to FIG. 20, the description continues. Following step S5, the coil portions 111B to 114B are attached to the valve main bodies 111A to 114A of the first to fourth solenoid valves 111 to 114 from the rear surface 163 side of the main body case 16, and the control of each solenoid valve, etc. Attach the electrical component for performing the above (step S6). Thus, the switching unit 1 is completed.

As described above, in the switching unit according to this embodiment, the first to third capillary tubes are arranged inside the first refrigerant pipe and the fourth refrigerant pipe. The first and second capillary tubes are arranged near the first refrigerant pipe, and the third capillary tube is arranged near the fourth refrigerant pipe and the third refrigerant pipe. By arranging the first to third capillary tubes near the outer circumference of the switching mechanism, it becomes easier to access each capillary tube from the outside, and the operation of attaching butyl rubber to each capillary tube can be easily performed. In addition, since the capillary tubes are arranged near the outer periphery of the switching mechanism without changing the dimension between the refrigerant pipes, the size of the switching unit can be kept small.

Furthermore, each capillary tube according to the present embodiment is arranged so that the plane formed by the circumference of the spiral pipe portion is parallel to the plane formed by the first refrigerant pipe and the second refrigerant pipe. As a result, even if the butyl rubber is attached to each capillary tube, the resistance received from each capillary tube and the butyl rubber can be reduced when the foaming stock solution is foamed inside the main body case, and the filler is attached to the main body. To fill the inside of the main body case with the foamed heat insulating material evenly and without gaps in the inside of the case.

1 switching unit 2 outdoor unit 3 indoor unit 10 switching mechanism 11 high pressure gas pipe 11a secondary high pressure gas pipe 12 low pressure gas pipe 12a secondary low pressure gas pipe 13 liquid pipe 13a secondary liquid pipe 14 indoor unit side gas connection pipe 15 indoor unit side liquid pipe Connection pipe 16 Body case 21 Outdoor heat exchanger 22 Compressor 23 Four-way valve 31 Indoor heat exchanger 32 Indoor expansion valve 33 Indoor unit gas pipe 34 Indoor unit liquid pipe 100 Switching mechanism group 101 First refrigerant pipe 102 Second refrigerant pipe 103 Third refrigerant pipe 104 Fourth refrigerant pipe 111 First solenoid valve 111A Valve body 111B Coil part 111C Pipe 112 Second solenoid valve 112A Valve body 112B Coil part 113 Third solenoid valve 113A Valve body 113B Coil part 114 Fourth solenoid valve 114A Valve body 114B Coil portion 121 First capillary tube 122 Second capillary tube 123 Third capillary tube 130 Joint piping 161 Upper surface 162 Front surface 163 Rear surface 164 Right side surface 165 Left side surface 166 Bottom surface 601 Inlet

Claims (5)

A switching unit connected to one or a plurality of outdoor units and a plurality of indoor units,
body case,
a first refrigerant pipe, a second refrigerant pipe, and a third refrigerant pipe arranged in order in the body case in a direction from the top surface to the bottom surface of the body case;
a first solenoid valve connected to the first refrigerant pipe and the second refrigerant pipe and opened when the indoor unit performs a heating operation;
A second electromagnetic valve that is opened and closed when communicating and blocking between a high-pressure side and a low-pressure side in a refrigerant flow path formed by the first refrigerant pipe, the second refrigerant pipe, and the third refrigerant pipe. and a third solenoid valve;
a fourth solenoid valve connected to the third refrigerant pipe and opened when the indoor unit performs a cooling operation;
a first pressure reducing mechanism arranged near the first refrigerant pipe and configured to reduce the pressure difference between both ends of the first solenoid valve according to the operations of the second solenoid valve and the third solenoid valve;
a second pressure reducing mechanism disposed near the third refrigerant pipe and configured to reduce the pressure difference between both ends of the fourth solenoid valve according to the operations of the second solenoid valve and the third solenoid valve;
a first noise reduction member attached to the first pressure reducing mechanism after connecting the first pressure reducing mechanism to the second electromagnetic valve and the third electromagnetic valve;
A switching unit, comprising: a second noise reduction member attached to the second pressure reducing mechanism after the second pressure reducing mechanism is connected to the second solenoid valve and the third solenoid valve. a third decompression mechanism disposed near the first refrigerant pipe and disposed at a position different from the first decompression mechanism in the axial direction of the first refrigerant pipe;
a third noise reduction member attached to the third pressure reducing mechanism after connecting the third pressure reducing mechanism to the first refrigerant pipe;
A switching unit according to claim 1, further comprising: 3. The switching unit according to claim 2, wherein the first pressure reducing mechanism and the third pressure reducing mechanism are arranged near the first refrigerant pipe and above the third refrigerant pipe. The refrigerant channel further has a fourth refrigerant pipe,
The fourth refrigerant pipe is shorter than the third refrigerant pipe and arranged below the third refrigerant pipe in a direction from the top surface to the bottom surface,
The second pressure reducing mechanism is arranged in a region of the third refrigerant pipe where the fourth refrigerant pipe is not arranged and in the vicinity of the third refrigerant pipe. Switching unit described in 1. The first refrigerant pipe, the second refrigerant pipe, and the third refrigerant pipe are housed so that their pipe axis directions are parallel to the side surface, and the first pressure reducing mechanism and the second pressure reducing mechanism and a body case that houses the third decompression mechanism;
The first decompression mechanism, the second decompression mechanism, and the third decompression mechanism each have a spiral pipe, and a plane formed by the circumference of the spiral pipe is parallel to the side surface of the main body case. 4. The switching unit according to claim 2 or 3, characterized in that it is arranged such that

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