JP2021055935A - Switching unit - Google Patents

Abstract

To provide a switching unit capable of suppressing dew condensation on refrigerant piping and solenoid valves.SOLUTION: First refrigerant piping, second refrigerant piping, third refrigerant piping and fourth refrigerant piping are respectively connected to any of an outdoor unit and an indoor unit, and disposed in a manner that their pipe axial directions are arranged in parallel with each other. A first solenoid valve, a second solenoid valve, a third solenoid valve and a fourth solenoid valve have valve bodies connected to any of the refrigerant piping, and coil portions for driving the valve bodies. The main body case 16 houses each refrigerant piping, the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve. A foam heat insulation material is charged into the main body case 16, and foams inside of the main body case 16 so that its volume is increased, thereby filling the main body case 16 in which the refrigerant piping, the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve are housed. The first refrigerant piping, the second refrigerant piping, the third refrigerant piping and the fourth refrigerant piping are disposed on different positions with respect to a direction of increase of the volume of the foam heat insulation material.SELECTED DRAWING: Figure 2

Description

The present invention relates to a switching unit.

Conventionally, there has been known a switching unit which is provided between one or a plurality of outdoor units and a plurality of indoor units in a multi-chamber air conditioner and has a function of switching between cooling operation and heating operation. The switching unit is a unit that combines a refrigerant pipe and a plurality of solenoid valves that form a part of the refrigerant circuit of the multi-chamber air conditioner. In the switching unit, one or more outdoor units and a plurality of indoor units are connected by three refrigerant pipes of 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 installed in a multi-chamber air conditioner that can perform so-called free heating and cooling operation that can be selected, and one of the high-pressure gas pipes or low-pressure gas pipes is operated indoors by operating some of the plurality of solenoid valves. By selecting the flow path connected to the machine, the operation of the indoor unit is switched to the cooling operation or the heating operation.

Further, in recent years, it has been desired to switch the cooling and heating of more indoor units with one switching unit. For example, it has been proposed that one switching unit can 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 the ceiling, and the size of the space where the switching unit can be placed is limited, and it is desirable to reduce the housing size in order to carry it to the ceiling. .. Further, when considering the installation work behind the ceiling, it is difficult to take a large space occupied behind the ceiling of the switching unit. If the size between the refrigerant pipes is simply increased, the size of the switching unit becomes larger due to the increase in the number of refrigerant pipes arranged inside the housing, which makes it difficult to arrange the switching unit in the ceiling. Therefore, it is physically difficult to increase the dimensions between the refrigerant pipes.

Further, the inside of the main body case is filled with a heat insulating material in order to prevent dew condensation from occurring in the refrigerant pipe and the solenoid valve to be accommodated. 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-component simple foamed rigid urethane foam in which liquid A mainly composed of isocyanate and liquid B mainly composed of polyol are mixed is used. When the liquid stock solution immediately after mixing the liquid A and the liquid B is injected into the main body case of the switching unit, the liquid A and the liquid B react inside the main body case to foam the liquid stock solution, and the main body The inside of the case is filled with foam insulation.

Japanese Unexamined Patent Publication No. 2014-25668

In recent years, it has been required to switch the cooling and heating of more indoor units with one 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 switch between cooling and heating. In the switching unit connected to a large number of indoor units in this way, the density of the refrigerant pipes increases inside the main body case by increasing the number of refrigerant pipes arranged inside the main body case. When the density of the refrigerant pipes becomes high, when the urethane foam is foamed, each refrigerant pipe becomes a resistance, and it becomes difficult for the foaming to proceed between the refrigerant pipes, before the foamed heat insulating material is filled between the refrigerant pipes. There is a risk that foaming will be completed. If a space where the foamed heat insulating material does not exist is generated around each refrigerant pipe, there is a problem that each refrigerant pipe is exposed to air in this space and dew condensation occurs. Further, in order to reduce the resistance to foaming, if the refrigerant pipes are arranged by increasing the distance between the refrigerant pipes so that the density of the refrigerant pipes is low, the size of the main body case becomes large.

The switching unit is generally placed in a narrow space such as the ceiling, and the size of the space where the switching unit can be placed is limited, and it is desirable to reduce the housing size in order to carry it to the ceiling. .. Furthermore, when considering the installation work behind the ceiling, it is difficult to take too much space behind the ceiling of the switching unit. If the dimensions between the refrigerant pipes are simply increased in consideration of the progress of foaming, the dimensions of the main body case of the switching unit will be increased, so that it is difficult to increase the dimensions of the refrigerant pipes.

On the other hand, if the piping density inside the main body case is increased so that the size of the main body case of the switching unit does not become large, as described above, each refrigerant pipe becomes a resistance when the foamed heat insulating material is foamed, and the foamed heat insulating material is used. May not reach every corner inside the housing. The foamed heat insulating material is made by injecting a liquid foamed heat insulating material into the main body case, arriving at the bottom surface of the main body case, and then foaming and expanding, so that the volume gradually increases from the bottom surface to the upper side inside the main body case. To increase. In order to spread the foamed heat insulating material without gaps in the dense refrigerant pipes, it is important to secure a path through which the foamed heat insulating material passes between the refrigerant pipes. For example, when the distance between the refrigerant pipes is narrow, the refrigerant pipes arranged close to each other resist the movement of the foamed heat insulating material during foaming, and the foaming is completed before the foamed heat insulating material passes between the refrigerant pipes. As a result, there will be places where the foamed heat insulating material does not reach. If the location where the foamed heat insulating material did not reach is around the refrigerant pipe or solenoid valve, there will be a spot where the refrigerant pipe or solenoid valve is not covered with the foamed heat insulating material, and dew condensation will occur at that location. There is a risk of

The disclosed technique has been made in view of the above, and an object of the present invention is to provide a switching unit capable of spreading a foaming agent inside a main body case.

The switching unit disclosed in the present application is connected to one or a plurality of outdoor units and a plurality of indoor units in one embodiment. The first refrigerant pipe, the second refrigerant pipe, the third refrigerant pipe, and the fourth refrigerant pipe are each connected to either the outdoor unit or the indoor unit, and the respective pipe axial directions are arranged in parallel. Be placed. The first solenoid valve, the second solenoid valve, the third solenoid valve, and the fourth solenoid valve are a refrigerant pipe including the first refrigerant pipe, the second refrigerant pipe, the third refrigerant pipe, and the fourth refrigerant pipe. It has a valve body connected to any of the above and a coil portion for driving the valve body. The main body case stores each of the refrigerant pipes and each of the solenoid valves. The foamed heat insulating material is injected into the main body case and foams inside the main body case to increase the volume, whereby the refrigerant pipe, the first solenoid valve, the second solenoid valve, the third solenoid valve and the fourth solenoid valve are used. The main body case in which the valve is stored is filled. Further, the first refrigerant pipe, the second refrigerant pipe, the third refrigerant pipe, and the fourth refrigerant pipe are arranged at different positions with respect to the direction in which the volume of the foamed heat insulating material increases. Will be done.

On one side, the present invention allows the foaming agent to be distributed inside the housing.

It is the schematic of the air-conditioning system which concerns on Example. It is a perspective view of the switching unit 1. It is a perspective view of the switching mechanism 10 mounted on the switching unit 1. It is a side view of a single switching mechanism 10. It is a figure which looked at the two sets of switching mechanisms 10 from the top surface. It is a front view of the switching mechanism 10. It is a figure for demonstrating brazing of the joint pipe 130 in the 1st solenoid valve 111. It is a perspective view for demonstrating brazing of a 1st solenoid valve 111 and a sub high pressure gas pipe 11a. It is a perspective view which shows the connection state of the secondary low pressure gas pipe 12a. It is a perspective view of the secondary low pressure gas pipe 12a. It is a side view of the sub-low pressure gas pipe 12a. It is a rear view of the switching mechanism 10. It is a rear view of the switching mechanism 10 in a state where the coil part of each solenoid valve is removed. It is a figure which shows the mounting state of the switching mechanism group 100 at the time of sticking butyl rubber. It is a D1 arrow view of the switching mechanism group 100 in FIG. It is a D2 arrow view of the switching mechanism group 100 in FIG. It is a top view of the switching unit 1. It is a figure which shows the state which removed the upper surface 161 of the main body case 16. It is a figure which showed the process of laminating the foamed heat insulating material when the distance between the refrigerant pipes is short. It is a flowchart which shows the outline of the manufacturing process of a switching unit 1. It is a top view for demonstrating the brazing of the 2nd refrigerant pipe 102 and the 3rd refrigerant pipe 103 to the 1st solenoid valve 111 and the 4th solenoid valve 114. It is a perspective view for demonstrating the brazing of the 2nd refrigerant pipe 102 and the 3rd refrigerant pipe 103 to the 1st solenoid valve 111 and the 4th solenoid valve 114. It is a top view for demonstrating the brazing of the 2nd capillary tube 122 and the 3rd capillary tube 123 to the 2nd solenoid valve 112 and the 3rd solenoid valve 113. It is a perspective view for demonstrating the brazing of the 2nd capillary tube 122 and the 3rd capillary tube 123 to the 2nd solenoid valve 112 and the 3rd solenoid valve 113. It is a perspective view of a low pressure gas pipe assembly. It is a perspective view of a high pressure gas pipe assembly. It is a perspective view of an example of a pipe assembly 100A to 100C. It is a figure for demonstrating the state in which the piping part assembly 100A is incorporated in the support base 200. It is an external perspective view of the piping part assembly 100A to 100C. It is a perspective view which looked at the piping total assembly 100D with the solenoid valve partition plate 171 attached from the front side. It is a perspective view which looked at the piping total assembly 100D with the solenoid valve partition plate 171 attached from the back side. It is a perspective view for demonstrating attachment of a butyl rubber sheet. It is a figure which shows the process of mounting the total piping assembly 100D on the outer body 602. It is a perspective view of the state in which the indoor unit side liquid pipe connecting pipe 15 is connected to the auxiliary liquid pipe 13a. It is a perspective view of the state in which the pipe heat insulating material 131 and the pipe heat insulating material 151 are attached to the auxiliary liquid pipe 13a and the indoor unit side liquid pipe connecting pipe 15. It is a perspective view of the state in which the switching mechanism group 100, the auxiliary liquid pipe 13a, and the indoor unit side liquid pipe connecting pipe 15 are mounted on the outer body 602. It is a perspective view which saw the switching unit 1 from the bottom surface 166 side. It is a perspective view which saw the switching unit 1 from the upper surface 161 side.

Hereinafter, examples of the switching unit disclosed in the present application will be described in detail with reference to the drawings. The switching unit disclosed in the present application is not limited by the following examples.

FIG. 1 is a schematic view 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 turnout.

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

Further, 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 12a provided with a branch pipe connected to each switching mechanism 10 inside the switching unit 1. The sub-low pressure gas pipe 12a is a pipe arranged in the switching unit 1. When there are more than 12 indoor units 3, the other end of the sub-low pressure gas pipe 12a is connected to the switching mechanism 10 of the other 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 the other switching unit 1. Each of the plurality of pipes branched from one sub-low pressure gas pipe 12a connected to the low pressure gas pipe 12 extending from the outdoor unit 2 is connected to each switching mechanism 10.

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

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

<Outdoor unit configuration>
The outdoor unit 2 is arranged outside a building such as a condominium. The outdoor unit 2 has an outdoor heat exchanger 21, a compressor 22, and a four-way valve 23. Further, 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 that serve as a flow path for the refrigerant.

In the outdoor heat exchanger 21, one of the flow paths of the refrigerant is connected to the four-way valve 23 and the other is connected to the liquid pipe 13. The outdoor heat exchanger 21 operates as either a condenser or an evaporator. When the outdoor heat exchanger 21 functions as a condenser, the high-temperature and high-pressure gas discharged from the compressor 22 by switching the four-way valve 23 so as to communicate the discharge side of the compressor 22 and the outdoor heat exchanger 21. The refrigerant flows into the outdoor heat exchanger 21 and exchanges heat with the outside air taken into the outdoor unit 2 by the rotation of an outdoor fan (not shown) to condense and flow out to the liquid pipe 13.

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

The compressor 22 is a variable capacity compressor that can change the operating capacity by being driven by a motor (not shown) whose rotation speed is controlled by an inverter. In the compressor 22, the suction side is connected to the low pressure gas pipe 12, and the discharge side is connected to the high pressure gas pipe 11. The high-pressure gas pipe 11 having one end connected to the compressor 22 has the other end branched in the outdoor unit 2, one of which is connected to the sub-high-pressure gas pipe 11a of the switching unit 1, and the other of which is a four-way valve. Connected to 23. Further, in the low pressure gas pipe 12 having one end connected to the compressor 22, the other end is branched in the outdoor unit 2, one of the branches is connected to the sub high pressure gas pipe 11a of the switching unit 1, and the other is branched in all directions. It is connected to the 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 flow direction of the refrigerant, and has four a, b, c, and d ports as shown in FIG. The port a of the four-way valve 23 is connected to the low pressure gas pipe 12, the port b is connected to the outdoor unit heat exchanger 21, and the port c is connected to the high pressure gas pipe 11. Also, port d is closed. As shown by the solid line in FIG. 1, the port b and the port c of the four-way valve 23 communicate with each other and the port a and the port d are switched so that the port c of the four-way valve 23 discharges from the compressor 22. Connected to the side, the port b is connected to the outdoor unit heat exchanger 21, and the outdoor heat exchanger 21 functions as a compressor. Further, as shown by a broken line in FIG. 1, the port a of the four-way valve 23 is switched so that the port a and the port b communicate with each other and the port c and the port d communicate with each other, so that the port a of the four-way valve 23 becomes a compressor. It is connected to the inflow side of 22, the port b is connected to the outdoor unit 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 connected 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 status of each port is switched. Further, when the outdoor heat exchanger 21 operates as an evaporator, the four-way valve is connected so that the outdoor heat exchanger 21 is connected to the low pressure gas pipe 12 and the branched path of the high pressure gas pipe 11 is sealed. The connection state of each port of 23 is switched.

<Composition of indoor unit>
The 12 indoor units 3 are arranged indoors in a building such as a condominium. 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 the indoor unit side gas connection pipe 14 and the indoor unit side liquid pipe connection pipe 15.

In the indoor heat exchanger 31, one end of the refrigerant flow path is connected to the indoor unit side gas connection pipe 14, and the other end is connected to the pipe connected to the indoor expansion valve 32. The indoor heat exchanger 31 functions as a condenser when the indoor unit 3 operates as a heater. Further, the indoor heat exchanger 31 functions as an evaporator when the indoor unit 3 operates as an air conditioner.

When the indoor unit 3 performs the heating operation, the sub-high pressure gas pipe 11a and the indoor heat exchanger 21 are switched so as to communicate with each other by the corresponding switching mechanism 10 so that the indoor heat exchanger 31 functions as a condenser. Specifically, the high-pressure / high-temperature refrigerant flowing out from the outdoor unit 2 to 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 and exchanges heat with the indoor air taken into the indoor unit 3 by the rotation of an indoor fan (not shown) to condense. As a result, the taken-in indoor air is heated and discharged into the room to heat the room. The refrigerant flowing 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 connecting pipe 15.

Further, when the indoor unit 3 performs the cooling operation, the sub-low pressure gas pipe 12a and the indoor heat exchanger 21 are switched so as to communicate with each other by the corresponding switching mechanism 10 so that the indoor heat exchanger 31 functions as an evaporator. .. Specifically, the low-pressure / low-temperature refrigerant flowing out from the outdoor unit 2 to 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 and exchanges heat with the indoor air taken into the indoor unit 3 by the rotation of an indoor fan (not shown) to evaporate. As a result, the taken-in indoor air is cooled and discharged into the room to cool the room. The refrigerant flowing 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 degree of the indoor expansion valve 32 is adjusted according to the cooling capacity required when the indoor heat exchanger 31 operates as an evaporator, and the heating required when the indoor heat exchanger 31 operates as a condenser. The opening is adjusted according to the capacity.

<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. The switching unit 1 has a main body case 16 shown in FIG.

The main body case 16 has an upper surface 161 and 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 main body case 16 is in the "front" direction, the back 163 side is in the "rear" direction, the right side 164 side is in the "right" direction, the left side 165 side is in the "left" direction, and the upper surface 161 side. Is called the "up" direction, and the bottom surface 166 side is called the "down" direction. Here, it is assumed that the switching unit 1 is arranged behind the ceiling, and the main body case 16 is preferably small in size. In particular, the dimension in the height direction is preferably small, and the dimension in the height direction (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.

The sub-high pressure gas pipe 11a, the sub-low pressure gas pipe 12a, and the sub-liquid pipe 13a connected to the outdoor unit 2 are arranged so as to protrude from the left side surface 165 side 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 corresponding sub-high pressure gas pipe 11a and the sub-low pressure gas of another switching unit 1 are arranged. By connecting to each of the pipe 12a and the auxiliary liquid pipe 13a, the switching unit 1 can be added according to the number of indoor units 3. When the switching unit 1 is not added, the sub-high pressure gas pipe 11a, the sub-low pressure gas pipe 12a, and the sub-liquid pipe 13a derived from the right side surface 164 are closed with a lid (not shown). Further, a plurality of indoor unit-side gas connecting pipes 14 and indoor unit-side liquid pipe connecting pipes 15 that are connected to different indoor units 3 are arranged so as to project from the front surface 162 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 in the order of the sub-high pressure gas pipe 11a, the sub-liquid pipe 13a, and the sub-low pressure gas pipe 12a from the front side 162 side of the main body case 16 toward the back surface 163. line up. The respective pipe shafts of the sub-high pressure gas pipe 11a, the sub-low pressure gas pipe 12a, and the sub-liquid pipe 13a extend in the left-right direction of the main body case 16.

The indoor unit side gas connection pipe 14 is arranged on the upper side of 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 from one end of the third refrigerant pipe 103 to the indoor unit gas pipe 33. Further, the indoor unit side liquid pipe connecting pipe 15 is arranged on the lower side in 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 auxiliary liquid pipe 13a 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 so as to project forward from the front surface 162 of the main body case 16. The indoor unit side gas connection pipe 14 and the indoor unit side liquid pipe connection pipe 15 are arranged 12 by 12 in the left-right direction of the main body case 16. The pipe shafts 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. Twelve sets of the indoor unit side gas connection pipe 14 and the indoor unit side liquid pipe connection pipe 15 are provided as a pair arranged one above the other, and the twelve sets of the indoor unit side gas connection pipe 14 and the indoor unit are provided. The side liquid pipe connecting pipe 15 is connected to each of the 12 indoor units 3.

Sub-high pressure gas pipe 11a connected to high-pressure gas pipe 11, sub-low-pressure gas pipe 12a connected to low-pressure gas pipe 12, sub-liquid pipe 13a connected to liquid pipe 13, indoor unit side gas connection pipe 14 and indoor unit Each of the side liquid pipe connecting 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 housed inside the main body case 16 will be specifically described with reference to FIGS. 3 and 4. FIG. 3 is a perspective view of the switching mechanism 10 mounted on the switching unit 1. Further, FIG. 4 is a side view of the single switching mechanism 10. All 12 switching mechanisms 10 are stored in the main body case 16.

In the main body case 16 according to the present embodiment, 12 switching mechanisms 10 shown in FIG. 4 are arranged side by side as shown in FIG. In this way, all 12 switching mechanisms 10 are stored in the main body case 16. As shown in FIGS. 3 and 4, 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. Further, each switching mechanism 10 has a first capillary tube 121, a second capillary tube 122, and a third capillary tube 123. Further, the switching mechanism 10 includes a first solenoid valve 111, a second solenoid valve 112, a third solenoid valve 113, and a fourth solenoid valve 114. Further, the switching mechanism 10 is arranged between the liquid pipe 13 and the indoor unit side liquid pipe connecting pipe 15.

One end of the first refrigerant pipe 101 is connected to the sub-high pressure gas pipe 11a, and the other end is connected to the first solenoid valve 111. The first refrigerant pipe 101 is a pipe between the joint pipe 130 and the sub-high pressure gas pipe 11a. The first refrigerant pipe 101 of each switching mechanism 10 extends in the front-rear direction of the main body case 16 and is arranged side by side in the left-right direction of the main body case 16.

When the indoor unit 3 performs the heating operation, high-temperature and high-pressure refrigerant flows into the first refrigerant pipe 101 from the sub-high pressure gas pipe 11a. The refrigerant that has flowed into the first refrigerant pipe 101 flows to the second refrigerant pipe 102, which will be described later, via the first solenoid valve 111 that is opened during the heating operation. As described above, the first refrigerant pipe 101 is a pipe through which a high-temperature and high-pressure refrigerant flows, and since the state of the flowing refrigerant is a gas refrigerant, it is received from the first refrigerant pipe 101 as compared with the case where the liquid refrigerant flows. The pressure loss increases. When the pressure loss becomes large, the temperature of the refrigerant flowing to the indoor unit 3 decreases, and the heating capacity exerted by the indoor unit 3 decreases. Therefore, it is preferable to use the first refrigerant pipe 101 having a diameter as large as possible in order to keep the pressure loss to such an extent that the heating capacity exerted by the indoor unit 3 is not affected. For example, as the first refrigerant pipe 101, a pipe having a diameter of 15 mm or more is used. 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 solenoid valve 111 via the joint pipe 138, and the other end joins the third refrigerant pipe 103, which will 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 joint pipe 134 and the merging position with the third refrigerant pipe 103. The second refrigerant pipe 102 also extends in the front-rear direction of the main body case 16 and is arranged side by side in the left-right direction of the main body case 16.

When the indoor unit 3 performs the heating operation, a high-temperature and high-pressure refrigerant flows into the second refrigerant pipe 102 from the first solenoid valve 111 which is opened during the heating operation. Since the fourth solenoid valve 114 is closed during the heating operation, the refrigerant that has flowed into the second refrigerant pipe 102 flows into the gas connection pipe 14 on the indoor unit side. As described above, 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 becomes small. Therefore, it is possible to use a pipe having a diameter smaller than that of the first refrigerant pipe 101 as the second refrigerant pipe 102. For example, as the second refrigerant pipe 102, a pipe having a diameter of 12 mm or more is used. 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. Then, 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 pipe 103 also extends in the front-rear direction of the main body case 16 and is arranged side by side in the left-right direction of the main body case 16.

In the third refrigerant pipe 103, when the indoor unit 3 performs the cooling operation, the refrigerant in the gas-liquid two-phase state flows in from the gas connection pipe 14 on the indoor unit side. Since the first solenoid valve 111 is closed, the refrigerant that has flowed into the third refrigerant pipe 103 flows to the sub-low pressure gas pipe 12a via the fourth solenoid valve 114 that is open during the cooling operation. As described above, since the refrigerant in the gas-liquid two-phase state flows through the third refrigerant pipe 103 and contains the gas refrigerant, the pressure loss received from the third refrigerant pipe 103 is larger than that in the case where only the liquid refrigerant flows. .. When the pressure loss becomes large, the amount of the refrigerant flowing through the indoor unit 3 decreases, and the cooling capacity exerted by the indoor unit 3 decreases. Therefore, it is preferable to use the third refrigerant pipe 103 having a diameter as large as possible in order to keep the pressure loss to such an extent that the cooling capacity exhibited by the indoor unit 3 is not affected. For example, as the third refrigerant pipe 103, a pipe having a diameter of 15 mm or more is used. In this embodiment, the diameter of the third refrigerant pipe 103 is 15.88 mm.

One end of the fourth refrigerant pipe 104 is connected to the fourth solenoid valve 114 via the pipe 133, and the other end is connected to the sub-low pressure gas pipe 12a. The fourth refrigerant pipe 104 is a pipe between the pipe 133 extending from the outlet of the fourth solenoid valve 114 and the sub-low pressure gas pipe 12a. The fourth refrigerant pipe 104 also extends in the front-rear direction of the main body case 16 and is arranged side by side in the left-right direction of the main 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 passes 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 into the sub-low pressure gas pipe 12a. As described above, the fourth refrigerant pipe 104 is a pipe that sends out the refrigerant to the outdoor unit 2, and it is possible to use a pipe having a diameter smaller than that of the third refrigerant pipe 103. For example, as the fourth refrigerant pipe 104, a pipe having a diameter of 12 mm or more is used. 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. 5 is a top view of the two sets of switching mechanisms 10. The first refrigerant pipe 101 is arranged near the upper surface 161 of the main body case 16.

The second refrigerant pipe 102 is arranged directly below the first refrigerant pipe 101 in parallel with the first refrigerant pipe 101 at a distance L1 equal to or larger 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 may be 16 mm or more.

The third refrigerant pipe 103 is arranged below the second refrigerant pipe 102 at a distance L2 in the vertical direction from the second refrigerant pipe 102 as shown in FIG. 4, and the first refrigerant pipe 103 is arranged below the second refrigerant pipe 102 as shown in FIG. It is arranged at a position L7 away from the 101 and the second refrigerant pipe 102 in the left direction. That is, the second refrigerant pipe 102 and the third refrigerant pipe 103 is disposed at an angle to the bottom surface 166, the distance between the second refrigerant pipe 102 and the third refrigerant pipe ^{103, (L2 2 + L7 2)} 1 It is calculated by ^{/ 2.} Then, the third refrigerant pipe 103 is arranged at a distance equal to or larger than the diameter of the third refrigerant pipe 103 from the second refrigerant pipe 102. 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 it may be equal to or greater than 16 mm, the above-described ^(L2 2 + ^{L7 2) 1 The distance obtained by / 2} may be 16 mm or more.

The fourth refrigerant pipe 104 is arranged in parallel directly below the third refrigerant pipe 103 with a distance L3 equal to or larger 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 may 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 directions from the upper 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 the extension direction described later).

Further, in the pipe in which the second refrigerant pipe 102 and the third refrigerant pipe 103 merge and are connected to the indoor unit side gas connection pipe 14, the indoor unit side gas connection pipe 14 is required for brazing as shown in FIG. It is preferable that the distance L4 between the indoor unit and the liquid pipe connecting pipe 15 on the indoor unit side is 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 pipe connecting pipe 15 is 105 mm or more.

FIG. 6 is a front view of the switching mechanism 10. In order to secure the distance L4, the third refrigerant pipe 103, which is connected to the indoor unit side gas connection pipe 14 by merging the second refrigerant pipe 102 according to the present embodiment, is connected to the indoor unit side liquid pipe as shown in FIG. It is bent away from the pipe 15 and bent upward.

Here, as shown in FIGS. 4 and 6, there is a straight portion 301 having a length L6 that is about twice the diameter of the third refrigerant pipe 103 as a gripping allowance for bending to be applied to the third refrigerant pipe 103. Is preferable. The straight line portion 301 exists between the confluence point with the second refrigerant pipe 102 and the connection portion with the indoor unit gas connection pipe 14 in the third refrigerant pipe 103. That is, in order to bend the third refrigerant pipe 103, a straight portion 301 having a length L6 longer than the gripping allowance required for the bending process shown in FIG. 4 is formed in the third refrigerant pipe 103. For example, when the diameter of the third refrigerant pipe 103 is 15.88 mm, the length L6 is about 30 mm. By grasping the position corresponding to the 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 sub-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 secured at 25 mm or more in consideration of the variation 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 toward the upper side and also toward the right side. As a result, the straight portion 301 is perpendicular to the bottom surface 166 and is inclined with respect to the plane including the fourth refrigerant pipe 104.

By bending the third refrigerant pipe 103 described above, a distance that satisfies the requirements required at the time of brazing is secured as the distance L4 between the indoor unit side gas connection pipe 14 and the indoor unit side liquid pipe connection pipe 15. Moreover, the height dimension of the switching unit 1 in the vertical direction can be kept small while ensuring a distance of 25 mm or more as the distance L5 between the indoor unit side gas connection pipe 14 and the pipe 121a extending from the sub-high pressure gas pipe 11a.

The first solenoid 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 when the first solenoid valve 111 is opened, the sub-high pressure gas pipe 11a and the indoor unit side gas connection pipe 14 are connected to the first refrigerant pipe. It communicates through 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 the refrigerant inflow port, and the side connected to the second refrigerant pipe 102 serves as the refrigerant outlet.

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. As a feature of the pilot type solenoid valve, since the valve body is operated by utilizing the pressure difference, it is possible to increase the valve diameter as compared with the direct acting type solenoid valve which operates only by the electromagnetic force. The refrigerant flow path provided with the first solenoid valve 111 is a flow path through which a high-pressure refrigerant flows during heating operation, and as an electromagnetic valve incorporated in this flow path, a direct-acting solenoid that operates the valve body only by electromagnetic force. With a valve, the valve diameter is small, and the required heating capacity may not be secured. 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 for the flow path through which the high-pressure refrigerant flows during the heating operation.

Specifically, as shown in FIGS. 3 and 5, the first solenoid valve 111 has a valve body 111A and a coil portion 111B. Further, here, the pipe on the side connected to the first refrigerant pipe 101 of the first solenoid valve 111 is referred to as the pipe 111C. Further, the pipe 132 extends downward from the outlet of the first solenoid valve 111. Further, the joint pipe 130 is brazed in advance to the pipe 111C on the side of the first solenoid valve 111 to which the first refrigerant pipe 101 is connected. Further, a joint pipe 134 is brazed to the pipe 132.

The valve body 111A has a pilot valve that switches the communication and cutoff of the flow path connecting the sub-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 in the valve body 111A by electromagnetic force. When the pilot valve operates by the electromagnetic force generated in the coil portion 111B, the pressure at the upper part of the valve body (not shown) rises and becomes higher than the pressure at the lower part of the valve body, so that the valve body operates.

Before assembling the first solenoid valve 111 of the switching mechanism 10, the joint pipe 130 is connected to the pipe 111C in the valve body 111A by brazing in advance. FIG. 7 is a diagram for explaining brazing of the joint pipe 130 in the first solenoid valve 111. When the joint pipe 130 is brazed to the pipe 111C extending from the valve body 111A, as shown in FIG. 7, the valve body 111A has the pipe axis direction of the pipe 111C connecting the joint pipe 130 horizontal to the valve body 111A. Placed to be. Then, the joint pipe 130 is fitted to the pipe 111C placed in the state of FIG. 7, and brazing is performed at the brazing point P1. At the time of this brazing, water is sprinkled on the valve body 111A in order to keep the valve body 111A below the heat resistant temperature. In the state of FIG. 7, the valve body 111A and the brazed 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 brazed portion 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 sub-high pressure gas pipe 11a. In the assembling work of the switching mechanism 10, the joint pipe 130 previously assembled to the pipe 111C in a state where the first refrigerant pipe 101 is located under 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 pipe 111C connected to the valve body 111A and the first refrigerant pipe 101 are connected. The joint pipe 130 can increase the distance between the valve body 111A and the brazed portion P2. Here, when brazing the sub-high pressure gas pipe 11a and the joint pipe 130, if water is sprinkled on the valve body 111A, water will flow to the brazing portion P2, which makes brazing difficult. On the other hand, 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 can be splashed with water. Since there is no brazing portion P2, the brazing portion P2 can be reliably brazed. Further, the second refrigerant pipe 102 is brazed to the pipe 132 extending from the valve body 111A. In this case as well, since there is a distance between the brazed portion and the valve body 111A, the valve body 111A is protected by a wet cloth. can do.

The explanation will be continued by returning to FIG. The second solenoid 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. Further, 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 connecting pipe 14 are connected via the third capillary tube 123 and the third refrigerant pipe 103. Further, a second capillary tube 122 is connected in parallel to the second solenoid 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 a portion 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 "equal pressure"). Since the pressure difference between the pressure on the inlet side and the pressure on the outlet side of the solenoid valve is smaller in the flow path provided with the second solenoid valve 112 than in the first refrigerant pipe 101, the second solenoid provided in this flow path is provided. As the valve 112, a direct-acting solenoid valve in which the valve body operates only by electromagnetic force is used.

The second solenoid valve 112 has a valve body 112A and a coil portion 112B. The valve body 112A has a valve body (not shown) for switching communication and interruption 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 body 112A by electromagnetic force. The valve body of the valve body 112A operates by the electromagnetic force generated in the coil portion 112B.

The second solenoid valve 112 is opened before opening the first solenoid valve 111 to equalize the pressure between the inflow port and the outflow port 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 inflow port and the outflow port of the first solenoid valve 111 are equalized via the third capillary tube 123, and after the pressure equalization, the first solenoid valve 111 is equalized. By opening the solenoid valve 111, the generation of refrigerant flow noise is suppressed.

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

The third solenoid valve 113 has a valve body 113A and a coil portion 113B. The valve body 113A has a valve body (not shown) for switching communication and interruption of the flow path in which the third solenoid valve 113 is provided. The coil portion 113B is provided to operate the valve body provided in the valve body 113A by electromagnetic force. The valve body of the valve body 113A operates by the electromagnetic force generated in the coil portion 113B.

The third solenoid valve 113 is opened before the fourth solenoid valve 114 is opened to equalize the pressure between the inflow port and the outflow port of the fourth solenoid valve 114. Here, when the fourth solenoid valve 114 is opened in a state where the pressure difference between the inlet and the outlet of the fourth solenoid valve 114 is large, 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 inlet and outlet of the fourth solenoid valve 114 are equalized via the third capillary tube 123, and the fourth solenoid valve 114 is equalized after the pressure equalization. By opening the solenoid valve 114, the generation of 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 when the fourth solenoid valve 114 is opened, the flow path connecting the indoor unit side gas connection pipe 14 and the sub-low pressure gas pipe 12a It is a valve that switches between communication and shutoff. The side of the fourth solenoid valve 114 connected to the third refrigerant pipe 103 is the inflow port, and the side connected to the fourth refrigerant pipe 104 is the discharge port.

The fourth solenoid valve 114 is a pilot type solenoid valve. The refrigerant flow path provided with the fourth solenoid valve 114 is a flow path through which low-pressure refrigerant flows during cooling operation, and as an electromagnetic valve incorporated in this flow path, a direct-acting solenoid that operates the valve body only by electromagnetic force. With a valve, the valve diameter is small, and the required 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 for 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 133 and a pipe 135 extending from the valve main body 114A. The valve body 114A has a pilot valve that switches communication and shutoff of the flow path connecting the indoor unit side gas connection pipe 14 and the sub-low pressure gas pipe 12a. The coil portion 114B is provided to operate the pilot valve provided in the valve body 114A by electromagnetic force. When the pilot valve operates by the electromagnetic force generated in the coil portion 114B, the pressure at the upper part of the valve body (not shown) rises to be higher than the pressure at the lower part of the valve body, and the valve body operates.

The fourth solenoid valve 114 is opened when the indoor unit 3 operates as an air conditioner, and the indoor unit side gas connection pipe 14 and the sub-low pressure gas pipe 12a communicate with each other via the third refrigerant pipe 103 and the fourth refrigerant pipe 104. To do.

FIG. 9 is a perspective view showing a connected state of the sub-low pressure gas pipe 12a. FIG. 10 is a perspective view of the sub-low pressure gas pipe 12a. FIG. 11 is a side view of the sub-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.

Specifically, the sub-low pressure gas pipe 12a is provided with a hole for connecting the branch pipe 211A and the branch pipe 211B, and the hole is subjected to burring. In the burring process, in order to braze the branch pipe 211A and the branch pipe 211B to the sub-low pressure gas pipe 12a, the peripheral edge of the hole formed at a predetermined position of the sub-low pressure gas pipe 12a is directed away from the sub-low pressure gas pipe 12a. It is a process to pull out. In burring, the processing equipment is placed near the hole during processing. Therefore, it is necessary to provide a work area for burring between the holes, and for example, the distance between the holes is preferably 60 mm or more. 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.

Further, 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 by the refrigerant pipe, at each connection portion. 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 a problem that the refrigerant leaks 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 brazing distance is 30 mm.

Therefore, the branch pipe 211A and the branch pipe 211B of the sub-low pressure gas pipe 12a according to the present embodiment are not connected to the same location on the circumference of the sub-low pressure gas pipe 12a as shown in FIGS. 9 to 11. .. Specifically, as shown in FIGS. 10 and 11, the branch pipes 211A are arranged in a row in the pipe axis direction, and are formed in holes opened on the circumference of the sub-low pressure gas pipe 12a on the back side of the main body case 1. Be 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 axis direction, that is, a secondary low pressure. The gas pipe 12a is connected to a hole opened upward on the circumference in a line in the pipe axis direction.

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

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 in 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 coil portion 113B on the back surface 163 of the main body case 16. , The coil portion 1114B is arranged so as to protrude from the back surface 163. This is to make it easy to access 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.

FIG. 12 is a rear view of the switching mechanism 10. 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 have a coil portion 111B of the first solenoid valve 111 and a fourth solenoid valve in the vertical direction. The coil portion 112B of the second solenoid valve 112 and the coil portion 112B of the third solenoid valve 113 are arranged so as to be located between the coil portion 113B of the 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 displayed. Therefore, for convenience, the coil portion 112B is referred to as the second solenoid valve 112, and the coil portion 113B is used. The third solenoid valve 113 was used as the third solenoid valve 113. Further, in the description here, the coil portion 111B may be simply referred to as a first solenoid valve 111, and the coil portion 111B may be simply referred to as a second solenoid valve 112.

As described above, the first solenoid valve 111 is connected to the first refrigerant pipe 101 and is arranged in the vicinity of the upper surface 161 of the main body case 16. The pipe 132 extending from the outlet of the first solenoid valve 111 and connected to the second refrigerant pipe 102 is arranged so as to extend downward from the valve body 111A. Further, the fourth solenoid valve 114 is connected to the fourth refrigerant pipe 104 and is arranged in the vicinity of the bottom surface 166 of the main body case 16. The pipe 133 extending from the outlet of the fourth solenoid valve 114 and connected to the fourth refrigerant pipe 104 is arranged so as 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 132 and the pipe 130 connected to the valve body 111A face different directions. Similarly, in the fourth solenoid valve 114, the pipe 133 connected to the valve main body 114A and the pipe 135 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 pipe 136 and the pipe 137 connected to the valve body 112A face in the same direction. Similarly, in the third solenoid valve 113, the pipe 138 and the pipe 139 connected to the valve body 113A are oriented in the same direction. Therefore, the second solenoid valve 112 and the third solenoid valve 113 have a larger 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 so as to face the back surface 163, the pipe 132 is connected from the outlet of the first solenoid valve 111. The pipe 133 extends downward and is arranged so as to extend downward from the outlet of the fourth solenoid valve 114.

Here, the connection portion of the outlet of the first solenoid valve 111 needs to have a length of 16 mm from the lower end of the valve body 111A in consideration of heat conduction at the time of brazing to the valve body 11A. Further, it is necessary to secure 32 mm as the dimension of the pipe 132 required for bending the second refrigerant pipe 102 connected to the outlet. Therefore, it is preferable that 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, that is, the upper end of the pipe 132 is secured as a space for arranging the pipe 132.

The second solenoid valve 112 is positioned in the vertical direction between the first solenoid valve 111 and the third solenoid valve 113, and is shifted to the left so as not to interfere with the pipe 132 extending from the outlet of the first solenoid valve 111. Is placed in. Further, the second solenoid valve 112 is arranged so as not to interfere with the pipe 132 extending from the outlet 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 solenoid valve 112 overlaps the coil portion 111B of the first solenoid valve 111, and about half of the left and right width of the coil portion 112B is the coil portion 111B. It is in a state of protruding from. In addition, the first solenoid valve 111, the second solenoid valve 112, the third solenoid valve 113, and the first refrigerant pipe 101, the second refrigerant pipe 102, and the third solenoid valve 103 connected to the fourth solenoid valve 114, The fourth refrigerant pipe 104 extends straight in the front-rear direction and is bent in the middle between the vertical plane including the first solenoid valve 111 and the vertical plane including the second solenoid valve 112. Can be bent toward. Further, 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-right width of one set of switching mechanisms 10 can be suppressed to about 1.5 times that of the electromagnetic coil because about half of the left-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 of L8 or more described above from the connection port of the first solenoid valve 111.

Further, 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 linear solenoid valves, and are provided so that both of the two connection ports extend toward the front of the main body case 16. Since it is not necessary for the second solenoid valve 112 to secure a distance equivalent to the distance L8 provided in the portion of the pipe 132 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 connection portion or the second refrigerant pipe 102 and the third refrigerant pipe 103 connected to each connection 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 132 extending downward from the valve body 111A of the first solenoid valve 111. Further, the second solenoid valve 112 is arranged on the left side of the first solenoid valve 111 at a distance that does not interfere with the pipe 132 extending downward from the first solenoid valve 111 valve main body 111A. Then, the fourth solenoid valve 114 is arranged directly below the second solenoid valve 112. As a result, both the horizontal and vertical dimensions of the switching mechanism 10 can be shortened. Therefore, even if 12 sets of switching mechanisms 10 are mounted on the main body case 16 as in the present embodiment, the switching unit 1 The dimensions in the left-right direction and the up-down direction can be reduced respectively.

The second capillary tube 122 is arranged in the vicinity of the first refrigerant pipe 101. Further, the second solenoid valve 112 is arranged above the third solenoid valve 113. Therefore, the pipe 138 connecting the third solenoid valve 113, 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 132 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 132 extending downward from the discharge port of the first solenoid valve 111. To avoid.

FIG. 13 is a rear view of the switching mechanism 10 in a state where the coil portion of each solenoid valve is removed. The pipe 138 extending upward from the third solenoid valve 113 is inclined from the normal direction of the bottom surface 166 toward the upper left in consideration of interference with the pipe 132. As a result, the first solenoid valve 111 and the third solenoid valve 113 are separated from each other by avoiding interference between the pipe 132 extending downward from the discharge port of the first solenoid valve 111 and the pipe extending upward from the third solenoid valve 113. You can get closer.

The first capillary tube 121 is a decompression mechanism in which a thin pipe is formed in a spiral shape. 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-chamber 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, but at this time, the check valve makes it impossible to evacuate. .. Therefore, by providing the first capillary tube 121 so as to bypass the check valve as described above, when the inside of the refrigerant circuit is evacuated, the vacuum can be drawn via the first capillary tube 121. ..

When the refrigerant passes through the first capillary tube 121, a refrigerant flow noise is generated. In the following, the refrigerant flow noise may be referred to as the refrigerant noise. In order to reduce the refrigerant noise in the first capillary tube 121, butyl rubber is attached to the first capillary tube 121 before the switching mechanism group 100, which is a collection of 12 sets of switching mechanisms 10, is housed in the main body case 16. Butyl rubber is attached so as to sandwich the first capillary tube 121 between one sheet.

FIG. 14 is a diagram showing a mounting state of the switching mechanism group 100 when the butyl rubber is attached. In the butyl rubber pasting work, as shown in FIG. 14, the first solenoid valve 111, the second solenoid valve 112, and the fourth solenoid valve 114 in the switching mechanism group 100 are the indoor unit side gas connection pipe 14 and the indoor unit side liquid connection pipe. It is performed in a state where it is placed so as to be placed above 15. When the butyl rubber is attached, it is preferable that the first capillary tube 121 is arranged at a location easily accessible from the D1 direction and the D2 direction in FIG. Then, in order to carry out the work of attaching the butyl rubber, it is preferable to provide a gap of 20 mm or more on both sides of the first capillary tube 121 so that the operator's fingers can be easily inserted.

Here, the first capillary tube 121 is the first except for the one arranged between the first solenoid valve 111 and the sub-high pressure gas pipe 11a in the front-rear direction of the main body case 16 and to the rightmost in the left-right direction of the main body case 16. It is arranged between the 1 refrigerant pipes 101 and in the vertical direction of the main body case 16 between the 1st refrigerant pipe 101 and the 2nd refrigerant pipe 102 near the 1st refrigerant pipe 101, and has almost the same height as the 1st refrigerant pipe 101. It is arranged so as to be.

The first capillary tube 121 is preferably located at a position as close to the outside as possible of the switching mechanism 10 in order to facilitate the sticking work of the operator during the sticking work of the butyl rubber. Therefore, since the first capillary tube 121 is connected to the first refrigerant pipe 101, the first capillary tube 121 is shown in FIG. 14 in order to minimize the connection pipe between the first capillary tube 121 and the first refrigerant pipe 101. It is arranged in the vicinity of the first refrigerant pipe 101 which is easily accessible from the D1 direction of.

Further, the first capillary tube 121 is arranged so that the plane formed by the circumference of the spiral pipe is substantially parallel to the right side surface 164 or the left side surface 165 of the main body case 16. FIG. 15 is a D1 arrow view of the switching mechanism group 100 in FIG. As shown in FIG. 15, the first capillary tube 121 has a distance L11 from the first refrigerant pipe 101 on the right side of the first capillary tube 121 and the first refrigerant pipe 101 on the left side of the first capillary tube 121. They are arranged so that the distances L12 between them are both 20 mm or more. Here, the left and right in FIG. 5 are opposite to the left and right in the switching unit 1.

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

Like the first capillary tube 121, the second capillary tube 122 also generates a 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, which is a collection of 12 sets of switching mechanisms 10, is housed in the main body case 16. Be done. Butyl rubber is attached so as to sandwich the second capillary tube 122 with one sheet.

The second capillary tube 122 is also preferably present at a position as close to the outside as possible of the switching mechanism 10 in order to facilitate the sticking work of the operator during the sticking work of the butyl rubber. The second capillary tube 122 is a first refrigerant pipe except for the one arranged between the first electromagnetic valve 111 and the sub-high pressure gas pipe 11a in the front-rear direction of the main body case 16 and the rightmost one in the left-right direction of the main body case 16. Between 101, in the vertical direction of the main body case 16, it is arranged between the first refrigerant pipe 101 and the second refrigerant pipe 102 at a position from the first refrigerant pipe 101, and has almost the same height as the first refrigerant pipe 101. It is arranged so as to be. This makes it easier for the operator to access the second capillary tube 122 from the D1 direction of FIG. Here, the second capillary tube 122 is arranged on the back surface 163 side of the main body case 16 from the first capillary tube 121.

Further, the second capillary tube 122 is arranged so that the plane formed by the circumference of the spiral pipe is substantially parallel to the right side surface 164 or the left side surface 165 of the main body case 16. Then, as shown in FIG. 15, the second capillary tube 122 has a distance L21 between the second capillary tube 122 and the first refrigerant pipe 101 on the right side, and the first refrigerant pipe on the left side of the second capillary tube 122. The distance L22 from 101 is arranged so that both of them have a size that can be easily inserted by the operator's fingers, for example, 20 mm or more.

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

Like the first capillary tube 121 and the second capillary tube 122, the third capillary tube 123 also generates a 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, which is a collection of 12 sets of switching mechanisms 10, is housed in the main body case 16. Be done. Butyl rubber is attached so as to sandwich the third capillary tube 123 with one sheet.

The third capillary tube 123 is also preferably present at a position as close to the outside as possible of the switching mechanism 10 in order to facilitate the sticking work of the operator during the sticking 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 are connected. The third capillary tube 123 is arranged in the vicinity of the fourth refrigerant pipe 104 and the third refrigerant pipe 103, which are easily accessible from the D2 direction in FIG. 14, in order to minimize the connection pipe with the pipe. The third capillary tube 123 is the third refrigerant pipe 103 except for the one arranged between the sub liquid pipe 13a and the sub low pressure gas pipe 12a in the front-rear direction of the main body case 16 and the rightmost one in the left-right direction of the main body case 16. In the vertical direction of the main body case 16, by arranging it at a position from the third refrigerant pipe 103 between the third refrigerant pipe 103 and the fourth refrigerant pipe 104, it becomes easy to access from the D2 direction of FIG.

Further, the third capillary tube 123 is arranged so that the plane formed by the circumference of the spiral pipe is substantially parallel to the right side surface 164 or the left side surface 165 of the main body case 16. FIG. 16 is a D2 arrow view of the switching mechanism group 100 in FIG. 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 the third refrigerant pipe 103 on the right side of the third capillary tube 123. Both of them are arranged so that the distance L32 between them is such that the operator's fingers can be easily inserted, for example, 20 mm or more.

In this way, since 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, the workability of the butyl rubber pasting work is improved. The operator can easily access the first capillary tube 121, the second capillary tube 122, and the third capillary tube 123, and can surely and easily attach the butyl rubber.

After the switching mechanism group 100 is housed in the main body case 16, the foam heat insulating material is injected into the main body case 16 and the inside of the main body case 16 is filled with the foam heat insulating material. As a result, a portion of the switching mechanism group 100 housed inside the main body case 16 (a portion protruding outside the indoor unit side gas connecting pipe 14 and a portion protruding outside the indoor unit side liquid pipe connecting pipe 15). The coil portions (parts other than the coil portions 111B to 114B) are covered with the foamed heat insulating material, and dew condensation of 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 as viewed from above. Here, the injection and filling of the foamed heat insulating material will be described with reference to FIG. On the upper surface 161 of the main body case 16, a plurality of injection ports 601 for injecting the undiluted solution of the foamed heat insulating material before foaming are formed. In this embodiment, the injection port 601 is provided in a region on the upper surface 161 near the back surface 163 of the switching unit 1.

In this embodiment, as the foamed heat insulating material, for example, a two-component simple foamed rigid urethane foam in which liquid A mainly composed of isocyanate and liquid B mainly composed of polyol are mixed is used. The two-component simple foamed rigid urethane foam is liquid immediately after the liquid A and the liquid B are mixed. The liquid immediately after mixing the liquid A and the liquid B is hereinafter referred to as "foaming stock solution". Then, the mixed liquid A and liquid B undergo a chemical reaction and foam after a certain period of time to form a foam.

The foamed stock solution injected from the injection port 601 collects 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 on the upper part of the main body case 16. Therefore, the foamed stock solution is injected from the side of the first refrigerant pipe 101. Then, the foamed stock solution passes by the side of each refrigerant pipe in the order of the first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe 103, and the fourth refrigerant pipe 104, and reaches the bottom surface 166.

As described above, the first refrigerant pipe 101 and the second refrigerant pipe 102 are arranged side by side in a vertical direction. Further, the third refrigerant pipe 103 and the fourth refrigerant pipe 104 are arranged side by side in a vertical direction, 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 foamed undiluted solution injected from the plurality of injection ports 601 of the main body case 16 is the first refrigerant pipe 101 and the second refrigerant pipe 102 arranged vertically, and the third refrigerant pipe 103 and the fourth refrigerant arranged vertically. It flows between the pipe 104 and falls to the bottom surface 166.

When the foamed stock solution flows from the injection port 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 in a row in the vertical direction. Since they are arranged, the resistance when the foamed undiluted solution flows is reduced as compared with 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 the above 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 of the spiral pipes of the first capillary tube 121 to the third capillary tube 123 is formed. , It is arranged so as to be substantially parallel to the right side surface 164 or the left side surface 165 of the main body case 16. Therefore, the resistance received from each of the first capillary tubes 121 to the third capillary tubes 123 when the foamed stock solution flows from the injection port 601 to the bottom surface 166 can be reduced.

The foamed undiluted solution injected from the injection port 601 and reaching the bottom surface 166 spreads and accumulates at the bottom surface 166 of the main body case 16. Here, the first solenoid valve 111, the second solenoid valve 112, the third solenoid valve 113, and the fourth solenoid valve 114 are arranged in the vicinity of the back surface 163 of the main body case 16. Further, in the vicinity of the back surface 163 of the main body case 16, the first refrigerant pipe 101, the second refrigerant pipe 102, the third refrigerant pipe 103, and the fourth refrigerant pipe extending from each of the first solenoid valve 111 and the fourth solenoid valve 114 are located. There are 104. Therefore, the back surface 163 side of the main body case 16 has a higher density of each member constituting the switching mechanism 10 than the front surface 162 side, and the bottom surface 166 is injected from the injection port 601 as compared with the front surface 162 side of the main body case 16. The resistance of the foaming stock solution that flows to is large.

In the switching unit 1 of the present embodiment, in consideration of the difference in the density of each member constituting the switching mechanism 10 in the front-rear direction inside the main body case 16, the injection port 601 on the upper surface 161 is a region close to the back surface 163. It is provided in. As a result, the foamed stock solution falls from the upper side to the bottom surface 166 on the back surface 163 side where the member density is high, and flows from the back surface 163 side toward the front surface 162 side where the member density is low. Therefore, on the back surface 163 side where the members are highly dense, the foamed stock solution previously injected by the foamed stock solution injected from above is pushed downward to reach the bottom surface 166, and the foamed stock solution reaching the bottom surface 166 is generated. Since the members flow to the front 162 side, which has a lower density of the members than the back 163 side, that is, the resistance received from the members when the foam stock solution flows, the entire main body case 16 can be filled with the foam stock solution without excess or deficiency.

The foaming stock solution injected into the main body case 16 from the injection port 601 reacts with the liquid A and the liquid B 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 upward. 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 a process in which the foamed heat insulating material foams when the distance between the refrigerant pipes is short. At this time, as shown in FIG. 19, when the distance between the refrigerant pipes having a diameter of 12 mm or more among the refrigerant pipes stored inside the main body unit 16 is small, the foamed stock solution (hereinafter referred to as foamed heat insulating material 50) is described. When foaming upward, it becomes difficult for foaming to proceed between the refrigerant pipes, and foaming may be completed between the refrigerant pipes. In this way, when the foaming is completed between the refrigerant pipes, there is a possibility 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 diagonally upward, and when the space P3 is generated, the space P3 is used. There is a problem that each refrigerant pipe is exposed to air and dew condensation occurs.

Therefore, in the switching unit 1 according to the present embodiment, among the refrigerant pipes stored inside the main body unit 16, the first refrigerant pipe 101, the second refrigerant pipe 102, and the third refrigerant pipe having a diameter of 12 mm or more are used. Regarding the refrigerant pipe 103 and the fourth refrigerant pipe 104, the distance between them is set to a size that does not hinder the foaming of the foamed heat insulating material 50, for example, the distance between the two is set to a size equal to or larger than the diameter of each refrigerant pipe. That is, each of 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 foamed heat insulating material increases. As a result, when the foamed heat insulating material 50 foams upward between the refrigerant pipes, the foamed heat insulating material 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. Since it can be filled with 50, each refrigerant pipe is not exposed to air and dew condensation does not occur.

On the other hand, the switching unit 1 according to the present embodiment has a relatively thick first refrigerant pipe 101, a second refrigerant pipe 102, a third refrigerant pipe 103, and a fourth of the pipes of the switching mechanism 10 having a diameter of 12 mm or more. By providing a gap equal to or larger than the diameter of the adjacent refrigerant pipes between the refrigerant pipes 104, a wide space is provided between the refrigerant pipes so that the foamed heat insulating material does not interfere with the foaming of the foamed heat insulating materials. The space can be filled with foam insulation. As a result, it is possible to suppress the generation of a space such as the space P3 shown in FIG. 19 where the foamed heat insulating material does not reach, and the foamed heat insulating material is filled in the main body case 16 without a gap. Therefore, it is possible to suppress the occurrence of dew condensation in the main body case 16.

Further, the switching unit 1 according to the present embodiment has a relatively thick first refrigerant pipe 101, a second refrigerant pipe 102, a third refrigerant pipe 103, and a fourth refrigerant pipe having a diameter of 12 mm or more among the pipes of the switching mechanism 10. By providing a gap equal to or larger than the diameter of the adjacent refrigerant pipes between 104, a wide space is provided between the refrigerant pipes, and the space between the refrigerant pipes is not hindered when the foamed heat insulating material is foamed. Can be filled with foam insulation. As a result, it is possible to suppress the generation of a space such as the space P3 shown in FIG. 19 where the foamed heat insulating material does not reach, and the foamed heat insulating material is filled in the main body case 16 without a gap. Therefore, it is possible to suppress the occurrence of dew condensation in the main body case 16.

FIG. 20 is a flowchart showing an outline of the manufacturing process of the switching unit 1. Next, an outline of the manufacturing process of the switching unit 1 will be described with reference to FIG.

The joint pipe 130 is brazed to the pipe 111C of the first solenoid valve 111. At this time, as described above, the first solenoid valve 111 is placed sideways, and brazing is performed while sprinkling water on the valve body 111A with the brazing portion turned sideways (step S1). As a result, the first solenoid valve 111 in a state where the joint pipe 130 shown in FIG. 7 is connected to the valve body 111A is completed.

Here, the first solenoid valve 111 and the fourth solenoid valve 114 are both connected to a refrigerant pipe having a large diameter. The first refrigerant pipe 101 and the second refrigerant pipe 102 are connected to the first solenoid valve 111. Further, the third refrigerant pipe 103 and the fourth refrigerant pipe 104 are connected to the fourth solenoid valve 114. Generally, when brazing a refrigerant pipe having a large diameter, the amount of heat associated with brazing increases, so that the valve body is easily damaged. In this respect, since the pipes 133 and 135, which are the connecting portions of the fourth solenoid valve 114 according to the present embodiment, are long, there is a distance from the brazed portion and the valve main body 114A is not damaged. On the other hand, since the pipes 111C and 132 that are the connection portions of the refrigerant pipes in the first solenoid valve 111 are short, there is a high possibility that the valve main body 111A will be damaged by heat during brazing. Therefore, in the first solenoid valve 111, the joint pipe 130 is connected to the pipe 111C in advance, and the joint pipe 134 is connected to the pipe 132 in advance.

Next, the first solenoid valve 111 to the fourth solenoid valve 114, the first refrigerant pipes 101 to the fourth refrigerant pipe 104, and the first capillary tubes 121 to the third capillary tubes 123 are brazed to each other ( Step S2).

Here, the steps 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. Further, 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.

As shown in FIG. 21A, one end of the second refrigerant pipe 102 is brazed to the pipe 132 extending from the outlet of the first solenoid valve 111. At this time, in order to cool the first solenoid valve 111, brazing is performed with the first solenoid valve 111 covered with a wet cloth. A sufficient distance is secured from the valve 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. Further, one end of the third refrigerant pipe 103 is brazed to one connection portion of the fourth solenoid valve 114. Then, the other end of the second refrigerant pipe 102 is brazed to a position closer to the fourth solenoid valve 114 than the straight portion 301 in the third refrigerant pipe 103. The first solenoid valve 111, the fourth solenoid valve 114, the second refrigerant pipe 102, and the third refrigerant pipe 103 connected in this way are grouped into four as shown in FIG. 21B. Here, a part of the switching mechanism group 100 is created by combining the four switching mechanisms 10 into one set, and then three sets of the four switching mechanisms 10 are connected to form the entire switching mechanism group 100. In the following, 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 is referred to as a "discharge suction valve sub". It is called "gumi".

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. Further, 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.

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 solenoid valve 112 via a refrigerant pipe. Similarly, one end of the second capillary tube 122 and one end of the third capillary tube 123 are also connected to the third solenoid valve 113 via a refrigerant pipe. Then, by connecting the second capillary tube 122 and the third capillary tube 123, the second capillary tube 122 is located in the vicinity of the first solenoid valve 111, and the third capillary tube 123 is the fourth solenoid valve. It is located in the vicinity of 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 to each other are grouped together as shown in FIG. 22B. In the following, a set of four parts in which the second capillary tube 122 and the third capillary tube 123 are connected to the second solenoid valve 112 and the third solenoid valve 113 will be referred to as a "pressurized pressure reducing valve sub-assembly". ..

Returning to FIG. 20, the description of the assembly process will be continued. Following step S2, the sub-high pressure gas pipe 11a and the sub-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 of these holes. FIG. 23 is a perspective view of the low pressure gas pipe assembly. As described above, since the burred holes are provided at positions shifted by 90 degrees in the circumferential direction of the sub-low pressure gas pipe 12a, the branch pipes 211A and the branch pipes 211B are brazed to the respective holes. As shown in FIG. 23, the branch pipes 211A and the branch pipes 211B are arranged side by side in a line in the pipe axis direction, and the branch pipes 211A and the branch pipes 211B are displaced by 90 degrees in the circumferential direction. Be placed. A component in which four branch pipes 211A and 211B are connected to a portion of the sub-low pressure gas pipe 12a of the low pressure gas pipe 12 in this way is referred to as a "low pressure gas pipe assembly".

FIG. 24 is a perspective view of the high pressure gas pipe assembly. As shown in FIG. 24, the first refrigerant pipe 101 and the first capillary tube 121 are brazed to the sub-high pressure gas pipe 11a. A component in which four first refrigerant pipes 101 are connected to a portion of the sub-high pressure gas pipe 11a of the high pressure gas pipe 11 is referred to as a "high pressure gas pipe assembly".

Returning to FIG. 20, the description of the assembly process will be continued. Following step S3, four switching mechanisms 10 are assembled into one set (hereinafter, four switching mechanisms 10 are collectively referred to as piping subassemblies 100A to 100C) (step S4). .. FIG. 25 is a perspective view of an example of the piping subsets 100A to 100C. FIG. 25 shows the piping subset 100A arranged on the left side of the main body case 16. FIG. 26 is a diagram for explaining a state of being incorporated into a support base 200 formed of sheet metal to which the piping portion 100A is assembled. Specifically, as shown in FIG. 26, a low-pressure gas pipe set, a discharge / suction valve sub-set, a pressurized pressure-reducing valve sub-set, and a high-pressure gas pipe set are mounted and fixed on the support base 200 and brazed to each other. I do. At this time, for example, the joint pipe 130 connected to the pipe 111C of the first solenoid 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 portion and the valve body 111A can be secured, and the valve body 111A is covered with a wet cloth. As a result, the temperature rise of the valve body 11A can be suppressed.

FIG. 27 is an external perspective view of the piping subsets 100A to 100C. As shown in FIG. 27, in the main body case 16, in addition to the piping portion 100A, the piping portion 100B arranged in the center of the main body case 16 is arranged, and the piping part set 100C is arranged on the right side of the main body case 16. Will be done. Those including the piping subassemblies 100A to 100C are referred to as "total piping assembly 100D". By the process of step S4, the total piping assembly 100D is completed.

Returning to FIG. 20, the description of the assembly process will be continued. Following step S4, a housing assembly for accommodating the total piping 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 perspective view of the total piping assembly 100D with the solenoid valve partition plate 171 attached, as viewed from the front side. Further, FIG. 28B is a perspective view of the total piping assembly 10D with the solenoid valve partition plate 171 attached, as viewed from the rear side. First, as shown in FIGS. 28A and 28B, the solenoid valve partition plate 171 is attached to the back surface 163 side of the total piping assembly 100D.

FIG. 29 is a perspective view for explaining the attachment of the butyl rubber sheet. As shown in FIG. 29, the total piping assembly 100D is placed on the workbench with the solenoid valve partition plate 171 facing down. 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 the D1 direction, and the butyl rubber sheet 172 is attached to the third capillary tube 123 from the D2 direction. The butyl rubber sheet 172 is attached so as to sandwich each of the first capillary tube 121, the second capillary tube 122, and the third capillary tube 123 and cover them from both sides. In the drawings used for explaining the following steps, the butyl rubber sheet 172 is not shown.

FIG. 30 is a diagram showing a process of mounting the total piping assembly 100D on the outer cylinder 602. As shown in FIG. 30, the pipe insulation material 173 is attached to the pipe total assembly 100D. Specifically, the pipe heat insulating material 173 is attached to a position where the sub-high pressure gas pipe 11a and the sub-low pressure gas pipe 12a come into contact with the outer cylinder 602. The outer body 602 is a member that forms a part of the main body case 16. Then, the pipe total assembly 100D to which the pipe heat insulating material 173 is attached is mounted on the outer body 602. The state in which the total piping assembly 100D is mounted on the outer body 602 is shown in the lowermost view toward the paper surface of FIG. 30.

FIG. 31A is a perspective view showing a state in which the indoor unit side liquid pipe connecting pipe 15 is connected to the auxiliary liquid pipe 13a. Further, FIG. 31B is a perspective view showing a state in which the pipe heat insulating material 131 and the pipe heat insulating material 151 are attached to the auxiliary liquid pipe 13a and the indoor unit side liquid pipe connecting pipe 15. In parallel with the process of mounting the total pipe assembly 100D on the outer cylinder 602, the pipe heat insulating material 131 is attached to the auxiliary liquid pipe 13a shown in FIG. 31A, and the pipe heat insulating material 151 is attached to the indoor unit side liquid pipe connecting pipe 15. 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 auxiliary liquid pipe 13a and the indoor unit side liquid pipe connecting pipe 15 at a position where they come into contact with the outer cylinder 602.

FIG. 32 is a perspective view showing a state in which the switching mechanism group 100, the auxiliary liquid pipe 13a, and the indoor unit side liquid pipe connecting pipe 15 are mounted on the outer body 602. As shown in FIG. 32, the auxiliary liquid pipe 13a to which the indoor unit side liquid pipe connecting pipe 15 is connected is mounted on the outer body 602 on which the total piping assembly 100D is mounted. As a result, the switching mechanism group 100 is mounted on the outer body 602.

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

The foaming stock solution is injected into the switching unit 1 whose assembly is completed as described above from the injection port 601 provided on the upper surface 161. The effervescent undiluted solution injected into the main body case 167 collects and spreads at the bottom of the main body case 16 as described above, and then the foamed heat insulating material foams in the main body case 16 to insulate the foam in the main body case 16. The material is filled without gaps.

The explanation will be continued by returning to FIG. Following step S5, coil portions 111B to 114B are attached to the valve bodies 111A to 114A of the first solenoid valves 111 to 114 from the back surface 163 side of the main body case 16, and control of each solenoid valve is performed. (Step S6). As a result, the switching unit 1 is completed.

As described above, in the switching unit according to the present embodiment, four thick refrigerant pipes in the switching unit are arranged at a distance equal to or larger than the diameter of the refrigerant pipes adjacent to each other. As a result, it is possible to secure an inflow route to each space inside the main body case of the foamed heat insulating material, reduce the occurrence of places where the foamed heat insulating material does not reach due to the resistance of the refrigerant piping, and use the foamed heat insulating material as the main body. The case can be filled without gaps.

Further, in the switching unit according to the present embodiment, four refrigerant pipes are arranged side by side in parallel in the vertical direction of the main body case in the switching unit. As a result, the resistance received from the refrigerant pipe when the foaming stock solution is foamed can be reduced, and the foamed heat insulating material can be filled in the main body case without any gap.

Further, in the switching unit according to the present embodiment, an injection port for the foamed stock solution is provided on the side where the parts of the switching mechanism are densely arranged inside the main body case (in this embodiment, the back side of the main body case). As a result, after the foamed stock solution injected into the main body case from the injection port reaches the bottom surface below the injection port, from the back side of the main body case to the front side of the main body case, which is a space where the parts of the switching mechanism are sparsely arranged. Since it spreads toward the bottom, the foamed stock solution can be spread to the bottom surface, and the foamed heat insulating material can be filled in the main body case without any gaps.

1 Switching unit 2 Outdoor unit 3 Indoor unit 10 Switching mechanism 11 High-pressure gas pipe 11a Sub-high-pressure gas pipe 12 Low-pressure gas pipe 12a Sub-low-pressure gas pipe 13 Liquid pipe 13a Sub-liquid pipe 14 Indoor unit side gas connection pipe 15 Indoor unit side liquid pipe Connection pipe 16 Main 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 3rd refrigerant pipe 104 4th refrigerant pipe 111 1st electromagnetic valve 111A valve body 111B coil part 111C piping 112 2nd electromagnetic valve 112A valve body 112B coil part 113 3rd electromagnetic valve 113A valve body 113B coil part 114 4th electromagnetic valve 114A Valve body 114B Coil part 121 1st capillary tube 122 2nd capillary tube 123 3rd capillary tube 130 Joint piping 161 Top surface 162 Front surface 163 Back surface 164 Right side surface 165 Left side surface 166 Bottom surface 601 Injection port

Claims (3)

A switching unit connected to one or more outdoor units and a plurality of indoor units.
A first refrigerant pipe, a second refrigerant pipe, a third refrigerant pipe, and a fourth refrigerant, each of which is connected to either the outdoor unit or the indoor unit and arranged in parallel in the axial direction of each pipe. Plumbing and
It has a valve body connected to any one of the first refrigerant pipe, the second refrigerant pipe, the third refrigerant pipe, and the refrigerant pipe including the fourth refrigerant pipe, and a coil portion for driving the valve body. The first solenoid valve, the second solenoid valve, the third solenoid valve, the fourth solenoid valve, and
A main body case for storing each of the refrigerant pipes and each of the solenoid valves,
It is provided with a foamed heat insulating material that is injected into the main body case and foams inside the main body case to increase the volume, thereby filling the main body case.
The first refrigerant pipe, the second refrigerant pipe, the third refrigerant pipe, and the fourth refrigerant pipe are arranged at different positions with respect to the direction in which the volume of the foamed heat insulating material increases. A featured switching unit. The main body case is provided with an injection port for injecting the foamed heat insulating material.
Two of the first refrigerant pipe, the second refrigerant pipe, the third refrigerant pipe, and the fourth refrigerant pipe are set as a set, and the two refrigerant pipes of each of the sets are provided with the foamed heat insulating material. One of the refrigerant pipes is arranged on the downstream side of the other refrigerant pipe with respect to the direction in which the volume of the foam insulating material increases, and each of the above sets is arranged so as to be offset in the direction perpendicular to the flow direction of the foamed heat insulating material. The switching unit according to claim 1, wherein the switching unit is characterized in that. One of the refrigerant pipes included in the set is thicker than the other.
The switching unit according to claim 2, wherein the one refrigerant pipe is arranged downstream of the other refrigerant pipe in a direction in which the volume of the foamed heat insulating material increases.

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