INDOOR UNIT AND AIR CONDITIONER

An indoor unit includes a heat exchanger and a connection pipe, connected to the heat exchanger, through which a refrigerant flows. The connection pipe includes a first refrigerant pipe made of a first metal and a second refrigerant pipe made of a second metal higher in potential than the first metal. One end of the first refrigerant pipe is connected to the heat exchanger, and the other end of the first refrigerant pipe is connected to one end of the second refrigerant pipe. The first refrigerant pipe includes a vertical straight section, a bent section that is continuous with to a one end of the vertical straight section, and a horizontal straight section that is continuous with one end of the bent section. A covering member adheres to and covers the first refrigerant pipe from one end of the horizontal straight section to the bent section.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of PCT International Patent Application No. PCT/JP2022/018455, filed on Apr. 21, 2022, which claims priority under 35 U.S.C. § 119(a) to Japanese Patent Application No. 2021-161746, filed in Japan on Sep. 30, 2021. The contents of these applications are incorporated herein by reference in their entirety.

BACKGROUND

Technical Field

The present disclosure relates to an indoor unit and an air conditioner.

Discussion of the Background

Examples of a known indoor unit include an indoor unit constituting a part of an air conditioner (for example, JP 2015-140998 A). Such an indoor unit includes a casing and a heat exchanger disposed in the casing.

One end of a first refrigerant pipe is connected to the heat exchanger. One end of a second refrigerant pipe is connected to the other end of the first refrigerant pipe.

The first refrigerant pipe is formed of aluminum or an aluminum alloy. On the other hand, the second refrigerant pipe is formed of copper or a copper alloy.

SUMMARY

In one aspect, an indoor unit of the present disclosure includes:a heat exchanger; anda connection pipe that is connected to the heat exchanger and through which a refrigerant flows, in whichthe connection pipe includes:a first refrigerant pipe having one end connected to the heat exchanger, the first refrigerant pipe being formed of a first metal; anda second refrigerant pipe formed of a second metal having a smaller ionization tendency than an ionization tendency of the first metal of the first refrigerant pipe, the second refrigerant pipe having one end connected to the other end of the first refrigerant pipe,the first refrigerant pipe includes:a vertical straight section extending along an approximate vertical direction, the vertical straight section having an end adjacent to the second refrigerant pipe;a bent section that is continuous with the end of the vertical straight section and is bent, the bent section having an end adjacent to the second refrigerant pipe; anda horizontal straight section that is continuous with the end of the bent section and extends along an approximate horizontal direction, the horizontal straight section having an end adjacent to the second refrigerant pipe, anda covering member or a coating film is provided in intimate contact with (adheres to) the first refrigerant pipe to cover the first refrigerant pipe from the end of the horizontal straight section to the bent section.

Here, the portion adjacent to the second refrigerant pipe corresponds to a downstream portion in a direction of the flow of the refrigerant when the refrigerant flows from the first refrigerant pipe to the second refrigerant pipe, and corresponds to an upstream potion in a direction of the flow of the refrigerant when the refrigerant flows from the second refrigerant pipe to the first refrigerant pipe.

The approximate vertical direction means a vertical direction or a direction inclined at an angle of, for example, 20 degrees or less relative to the vertical direction.

The approximate horizontal direction means a horizontal direction or a direction inclined at an angle of, for example, 20 degrees or less relative to the horizontal direction.

Here, the portion adjacent to the first refrigerant pipe corresponds to an upstream portion in a direction of the flow of the refrigerant when the refrigerant flows from the first refrigerant pipe to the second refrigerant pipe, and corresponds to a downstream portion in a direction of the flow of the refrigerant when the refrigerant flows from the second refrigerant pipe to the first refrigerant pipe.

DESCRIPTION OF THE EMBODIMENTS

An indoor unit and an air conditioner of the present disclosure will be described in detail below with reference to embodiments illustrated in the drawings. Note that the same parts in the drawings are denoted by the same reference numerals to avoid the description from being redundant. Upper, lower, left, and right in the description correspond to upper, lower, left, and right in a state where an indoor unit is installed in a room.

First Example

FIG.1is a diagram illustrating a refrigerant circuit RC provided in an air conditioner of a first example of the present disclosure. This air conditioner is of a type in which an outdoor unit2is paired one-to-one with an indoor unit1.

The air conditioner includes the indoor unit1and the outdoor unit2connected to the indoor unit1via the refrigerant circuit RC.

The refrigerant circuit RC includes a compressor11, a four-way switching valve12, an outdoor heat exchanger13, an electric expansion valve14, an indoor heat exchanger15as an example of a heat exchanger, and an accumulator16. As the compressor11is driven, a refrigerant (for example, an HFC refrigerant such as R410A or R32) circulates in the refrigerant circuit RC.

More specifically, the four-way switching valve12has one end connected to a discharge-side portion of the compressor11. The four-way switching valve12has the other end connected to one end of the outdoor heat exchanger13. The outdoor heat exchanger13has the other end connected to one end of the electric expansion valve14. The electric expansion valve14has the other end connected to one end of the indoor heat exchanger15via a shutoff valve V1and a connection pipe L1. The indoor heat exchanger15has the other end connected to one end of the accumulator16via a connection pipe L2, a shutoff valve V2, and the four-way switching valve12. The accumulator16has the other end connected to an intake-side portion of the compressor11.

The indoor unit1is equipped with the indoor heat exchanger15and an indoor fan18. The indoor fan18is, for example, a cross-flow fan, and takes in indoor air through the indoor heat exchanger15.

The outdoor unit2is equipped with the compressor11, the four-way switching valve12, the outdoor heat exchanger13, the electric expansion valve14, the accumulator16, and an outdoor fan17.

The air conditioner switches the four-way switching valve12to a switching position indicated by a solid line to activate the compressor11for cooling operation and dehumidifying operation, and switches the four-way switching valve12to a switching position indicated by a dotted line to activate the compressor11for heating operation. A direction of a solid arrow inFIG.1indicates a direction in which the refrigerant flows during the cooling operation and the dehumidifying operation. A direction indicated by a dotted arrow inFIG.1indicates a direction in which the refrigerant flows during the heating operation.

FIG.2is a perspective view of the indoor unit1as viewed obliquely from above.FIG.3is a front view of the indoor unit1.

As illustrated inFIGS.2and3, the indoor unit1includes a casing21, and the indoor heat exchanger15, the indoor fan18, and the like are accommodated in the casing21.

An upper portion of the casing21is provided with an intake port22through which indoor air is taken in. When the indoor fan18is driven, indoor air enters the casing21through the intake port22and flows toward the indoor fan18. At this time, in order to prevent dust and the like from entering the casing21together with indoor air, a filter (not illustrated) is attached to the intake port22.

A lower portion of the casing21is provided with a blow-out port23through which air from the indoor fan18(indoor air subjected to heat exchange with the indoor heat exchanger15) blows out. A horizontal flap24is rotatably attached to a peripheral edge portion of the blow-out port23.

When the cooling operation or the like is started, the horizontal flap24changes its position from a stop position to close the blow-out port23to an operation position to open the blow-out port23to adjust a vertical airflow direction of air blown out from the blow-out port23.

FIG.4is a front view of the indoor heat exchanger15and a peripheral portion of the indoor heat exchanger15.

The indoor heat exchanger15includes a heat exchange portion151and a plurality of heat transfer tubes152extending through the heat exchange portion151in a left-right direction. The heat exchange portion151and the heat transfer tubes152are each formed of aluminum or an aluminum alloy.

The indoor unit1further includes a connection pipe30that is fluidly connected to the heat transfer tubes152of the indoor heat exchanger15and through which the refrigerant flows.

The connection pipe30includes a liquid-refrigerant connection pipe31constituting a part of the connection pipe L1and a gas-refrigerant connection pipe32constituting a part of the connection pipe L2. The liquid-refrigerant connection pipe31guides a liquid refrigerant from the electric expansion valve14to the indoor heat exchanger15during the cooling operation and the dehumidifying operation. On the other hand, the gas-refrigerant connection pipe32guides a gas refrigerant from the indoor heat exchanger15to the compressor11during the cooling operation and the dehumidifying operation. The liquid-refrigerant connection pipe31and the gas-refrigerant connection pipe32are each an example of the connection pipe.

Configuration of Liquid-Refrigerant Connection Pipe31

The liquid-refrigerant connection pipe31has includes a first liquid-refrigerant pipe311formed of aluminum or an aluminum alloy, and a second liquid-refrigerant pipe312formed of copper or a copper alloy. The first liquid-refrigerant pipe311has one end fluidly connected to the heat transfer tubes152of the indoor heat exchanger15. The first liquid-refrigerant pipe311is an example of a first refrigerant pipe. The aluminum and the aluminum alloy are each an example of a first metal. The second liquid-refrigerant pipe312is an example of a second refrigerant pipe. The copper and the copper alloy are each an example of a second metal.

The second liquid-refrigerant pipe312has one end fluidly connected to the other end of the first liquid-refrigerant pipe311through a third liquid-refrigerant pipe313formed of stainless steel. On the other hand, the second liquid-refrigerant pipe312has the other end fixed to a liquid-refrigerant flare union41by brazing. The third liquid-refrigerant pipe313is an example of a third refrigerant pipe (a stainless steel refrigerant pipe).

The third liquid-refrigerant pipe313has one end and the other end that is larger in outer diameter than the one end. The third liquid-refrigerant pipe313has the one end connected to an end of the first liquid-refrigerant pipe311adjacent to the third liquid-refrigerant pipe313. On the other hand, the third liquid-refrigerant pipe313has the other end connected to an end of the second liquid-refrigerant pipe312adjacent to the third liquid-refrigerant pipe313.

More specifically, the end of the third liquid-refrigerant pipe313adjacent to the first liquid-refrigerant pipe311is not enlarged in diameter, is inserted into the end of the first liquid-refrigerant pipe311adjacent to the third liquid-refrigerant pipe313, and is fixed to the first liquid-refrigerant pipe311by brazing. The end of the third liquid-refrigerant pipe313adjacent to the second liquid-refrigerant pipe312is enlarged in diameter, into which the end of the second liquid-refrigerant pipe312adjacent to the third liquid-refrigerant pipe313is inserted, and is fixed to the second liquid-refrigerant pipe312by brazing.

The end of the first liquid-refrigerant pipe311adjacent to the third liquid-refrigerant pipe313is enlarged in diameter in a manner similar to the end of the third liquid-refrigerant pipe313adjacent to the second liquid-refrigerant pipe312to be larger in outer diameter than the other portion of the first liquid-refrigerant pipe311.

Configuration of Gas-Refrigerant Connection Pipe32

The gas-refrigerant connection pipe32is similar in configuration to the liquid-refrigerant connection pipe31, and includes a first gas-refrigerant pipe321formed of aluminum or an aluminum alloy, and a second gas-refrigerant pipe322formed of copper or a copper alloy. The first gas-refrigerant pipe321is an example of the first refrigerant pipe. The second gas-refrigerant pipe322is an example of the second refrigerant pipe.

The first gas-refrigerant pipe321has one end fluidly connected to the heat transfer tubes152of the indoor heat exchanger15.

The second gas-refrigerant pipe322has one end fluidly connected to the other end of the first gas-refrigerant pipe321through a third gas-refrigerant pipe323formed of stainless steel. On the other hand, the second gas-refrigerant pipe322has the other end fixed to a gas-refrigerant flare union42by brazing.

FIG.5is a front view of the liquid-refrigerant connection pipe31and a peripheral portion of the liquid-refrigerant connection pipe31.FIG.6is a top view of the liquid-refrigerant connection pipe31and the peripheral portion of the liquid-refrigerant connection pipe31.FIG.7is a left-side view of the liquid-refrigerant connection pipe31and the peripheral portion of the liquid-refrigerant connection pipe31.

The first liquid-refrigerant pipe311of the liquid-refrigerant connection pipe31includes a vertical straight section311aextending along an approximate vertical direction. The approximate vertical direction refers to a vertical direction or refers to a direction inclined at an angle of, for example, 20 degrees or less relative to the vertical direction.

Configuration of First Liquid-Refrigerant Pipe311Adjacent to Second Liquid-Refrigerant Pipe312

The first liquid-refrigerant pipe311includes a bent section311bformed integrally with the vertical straight section311a, i.e., seamlessly with the vertical straight section311a. The bent section311bis located adjacent to the second liquid-refrigerant pipe312relative to the vertical straight section311a. That is, the bent section311bis positioned closer to the second liquid-refrigerant pipe312than the vertical straight section311a. The bent section311bis continuous with a lower end of the vertical straight section311aand is bent from the lower end toward the second liquid-refrigerant pipe312. The lower end of the vertical straight section311acorresponds to an end of the vertical straight section311aadjacent to the second liquid-refrigerant pipe312(i.e., an end on the second liquid-refrigerant pipe side).

The first liquid-refrigerant pipe311further includes a horizontal straight section311cformed integrally with the bent section311b, i.e., seamlessly with the bent section311b. The horizontal straight section311cis located adjacent to the second liquid-refrigerant pipe312relative to the bent section311b. That is, the horizontal straight section311cis positioned closer to the second liquid-refrigerant pipe312than the bent section311b. The horizontal straight section311cis continuous with an end of the bent section311badjacent to the second liquid-refrigerant pipe312(i.e., an end on the second liquid-refrigerant pipe side) and extends along an approximate horizontal direction. The approximate horizontal direction refers to a horizontal direction or a direction inclined at an angle of, for example, 20 degrees or less relative to the horizontal direction.

The first liquid-refrigerant pipe311has an outer peripheral surface extending from an end of the horizontal straight section311cadjacent to the second liquid-refrigerant pipe312(i.e., an end on the second liquid-refrigerant pipe side) to an end of the bent section311badjacent to the vertical straight section311a, the outer peripheral surface being entirely covered with a waterproof tube51. The waterproof tube51is formed of a tube made of a waterproof material (for example, vinyl chloride, silicone rubber, fluorine-based polymer, or the like) and shrunk by heating. Accordingly, the waterproof tube51is in intimate contact with the outer peripheral surfaces of the bent section311band the horizontal straight section311c. The waterproof tube51is an example of a covering member.

The waterproof tube51is also in intimate contact with an outer peripheral surface of the end of the third liquid-refrigerant pipe313adjacent to the first liquid-refrigerant pipe311to cover the entire circumference of the end.

Configuration of First Liquid-Refrigerant Pipe311Adjacent to Indoor Heat Exchanger15

The first liquid-refrigerant pipe311includes a curved section311dformed integrally with the vertical straight section311a, i.e., seamlessly with the vertical straight section311a. The curved section311dis located adjacent to the indoor heat exchanger15relative to the vertical straight section311a. That is, the curved section311dis positioned closer to the indoor heat exchanger15than the vertical straight section311a. A lower right end of the curved section311dis continuous with an upper end of the vertical straight section311a. The curved section311dhas a shape curved from the upper end of the vertical straight section311atoward the indoor heat exchanger15like a U-turn. The lower right end of the curved section311dcorresponds to an end of the curved section311dadjacent to the second liquid-refrigerant pipe312. The upper end of the vertical straight section311acorresponds to an end of the vertical straight section311aadjacent to the indoor heat exchanger15.

The first liquid-refrigerant pipe311includes a bent connecting section311eformed integrally with the curved section311d, i.e., seamlessly with the curved section311d. The bent connecting section311eis located adjacent to the indoor heat exchanger15relative to the curved section311d. That is, the bent connecting section311eis positioned closer to the indoor heat exchanger15than the curved section311d. The bent connecting section311eis continuous with a lower left end of the curved section311dand is bent from the lower left end toward a flow divider33. The lower left end of the curved section311dcorresponds to an end of the curved section311dadjacent to the indoor heat exchanger15.

The first liquid-refrigerant pipe311includes a straight connecting section311fformed integrally with the bent connecting section311e, i.e., seamlessly with the bent connecting section311e. The straight connecting section311fis located adjacent to the indoor heat exchanger15relative to the bent connecting section311e. That is, the straight connecting section311fis positioned closer to the indoor heat exchanger15than the bent connecting section311e. The straight connecting section311fextends from an end of the bent connecting section311eadjacent to the indoor heat exchanger15to the flow divider33.

The flow divider33is formed of aluminum or an aluminum alloy. A branch pipe34formed of aluminum or an aluminum alloy is fixed to an end of the flow divider33adjacent to the indoor heat exchanger15by brazing.

In the air conditioner configured as described above, the outer peripheral surfaces of the bent section311band the horizontal straight section311cof the first liquid-refrigerant pipe311are entirely covered with the waterproof tube51. Accordingly, for example, even when dew condensation water containing copper ions flows from the second liquid-refrigerant pipe312toward the first liquid-refrigerant pipe311, it is possible to prevent dew condensation water from adhering to the bent section311band the horizontal straight section311cof the first liquid-refrigerant pipe311. In short, the waterproof tube51can reduce the possibility that dew condensation water containing copper ions adheres to the bent section311band the horizontal straight section311cof the first liquid-refrigerant pipe311. It is therefore possible to prevent the first liquid-refrigerant pipe311from suffering electrolytic corrosion.

Since the waterproof tube51is in intimate contact with the outer peripheral surface of the first liquid-refrigerant pipe311, it is possible to reduce the possibility that liquid such as dew condensation water enters a space between the waterproof tube51and the first liquid-refrigerant pipe311. It is therefore possible to enhance the effect of preventing the first liquid-refrigerant pipe311from suffering electrolytic corrosion.

Since the waterproof tube51further covers the outer peripheral surface of the end of the third liquid-refrigerant pipe313adjacent to the first liquid-refrigerant pipe311, it is possible to reduce the possibility that liquid enters the space between the first liquid-refrigerant pipe311and the waterproof tube51from the other end of the first liquid-refrigerant pipe311. It is therefore possible to enhance the effect of preventing the first liquid-refrigerant pipe311from suffering electrolytic corrosion.

Since the waterproof tube51is formed so as not to cover the vertical straight section311aof the first liquid-refrigerant pipe311, the waterproof tube51can be made short in an axial direction as compared with a case where the waterproof tube51is formed so as to cover the vertical straight section311aof the first liquid-refrigerant pipe311. It is therefore possible to suppress an increase in manufacturing cost of the waterproof tube51.

Even if liquid such as dew condensation water adheres to the vertical straight section311aof the first liquid-refrigerant pipe311, the liquid flows down toward the bent section311bbecause the vertical straight section311aextends in the approximate vertical direction. Therefore, even if the outer peripheral surface of the vertical straight section311aof the first liquid-refrigerant pipe311is not covered with the waterproof tube51, the risk of causing the vertical straight section311ato suffer electrolytic corrosion is low.

In the air conditioner of the first example, one indoor unit1is connected to one outdoor unit2, or alternatively, a plurality of indoor units1may be connected. In other words, the above-described air conditioner is of a pair-type, or alternatively, the air conditioner may be of a multi-type.

The first liquid-refrigerant pipe311is formed of aluminum or an aluminum alloy in the first example, or alternatively, may be formed of metal other than aluminum and an aluminum alloy. Also in this case, the metal of which the first liquid-refrigerant pipe311is formed is selected so as to be lower in potential than the metal of which the second liquid-refrigerant pipe312is formed.

The second liquid-refrigerant pipe312is formed of copper or a copper alloy in the first example, or alternatively, may be formed of metal other than copper or a copper alloy. Also in this case, the metal of which the second liquid-refrigerant pipe312is formed is selected so as to be higher in potential than the metal of which the first liquid-refrigerant pipe311is formed.

The first gas-refrigerant pipe321is formed of aluminum or an aluminum alloy in the first example, or alternatively, may be formed of metal other than aluminum and an aluminum alloy. Also in this case, the metal of which the first gas-refrigerant pipe321is formed is selected so as to be lower in potential than the metal of which the second gas-refrigerant pipe322is formed.

The second gas-refrigerant pipe322is formed of copper or a copper alloy in the first example, or alternatively, may be formed of metal other than copper or a copper alloy. Also in this case, the metal of which the second gas-refrigerant pipe322is formed is selected so as to be higher in potential than the metal of which the first gas-refrigerant pipe321is formed.

The flow divider33and the branch pipe34are interposed between the heat transfer tubes152of the indoor heat exchanger15and the one end of the first liquid-refrigerant pipe311in the first example, or alternatively, the flow divider33and the branch pipe34need not be interposed. In other words, the one end of the first liquid-refrigerant pipe311may be directly connected to the heat transfer tubes152of the indoor heat exchanger15.

The flow divider33that divides one refrigerant flow into two refrigerant flows is used in the first example, or alternatively, a flow divider33that divides one refrigerant flow into three or more refrigerant flows may be used.

The third liquid-refrigerant pipe313is interposed between the other end of the first liquid-refrigerant pipe311and one end of the second liquid-refrigerant pipe312in the first example, or alternatively, the third liquid-refrigerant pipe313need not be interposed. In other words, for example, the second liquid-refrigerant pipe312may have one end directly connected to the other end of the first liquid-refrigerant pipe311.

The waterproof tube51is provided on the liquid-refrigerant connection pipe31in the first example, or alternatively, may be provided on the gas-refrigerant connection pipe32in a manner similar to the case where waterproof tube51is provided on the liquid-refrigerant connection pipe31.

The waterproof tube51covers the entire outer peripheral surface of the bent section311bin the first example, or alternatively, may cover only the outer peripheral surface of the end of the bent section311badjacent to the horizontal straight section311cand need not cover the outer peripheral surface of the other part of the bent section311b.

The waterproof tube51is formed so as not to cover the outer peripheral surface of the end of the third liquid-refrigerant pipe313adjacent to the second liquid-refrigerant pipe312in the first example, or alternatively, may be formed so as to cover the outer peripheral surface of the end of the third liquid-refrigerant pipe313adjacent to the second liquid-refrigerant pipe312. In other words, for example, the waterproof tube51may be formed so as to cover the entire outer peripheral surface of the third liquid-refrigerant pipe313.

The outer peripheral surfaces of the bent section311band the horizontal straight section311cof the first liquid-refrigerant pipe311is covered with the waterproof tube51in the first example, or alternatively, the outer peripheral surfaces of the bent section311band the horizontal straight section311cof the first liquid-refrigerant pipe311may be covered with a coating film. The coating film is made of a waterproof material (for example, fluororesin, fiber reinforced plastic (FRP), acrylic rubber, or the like). For example, the material may have heat resistance or elasticity.

For example, the coating film may be formed so as not to cover the outer peripheral surface of the third liquid-refrigerant pipe313or so as to cover the outer peripheral surface of the third liquid-refrigerant pipe313. In a case where the outer peripheral surface of the third liquid-refrigerant pipe313is covered with the coating film, at least a connection point between the first liquid-refrigerant pipe311and the third liquid-refrigerant pipe313needs to be covered with the coating film.

Second Example

FIG.8is an enlarged view of a main portion of a liquid-refrigerant connection pipe2031of an air conditioner of a second example of the present disclosure. The air conditioner of the second example is similar in configuration to the air conditioner of the first example except for a configuration between the other end of the first liquid-refrigerant pipe311and the liquid-refrigerant flare union41.

In the air conditioner of the second example, the liquid-refrigerant connection pipe2031includes a second liquid-refrigerant pipe2312formed of stainless steel. The second liquid-refrigerant pipe2312has one end fluidly connected to the other end of the first liquid-refrigerant pipe311without the third liquid-refrigerant pipe313. The second liquid-refrigerant pipe2312is an example of the second refrigerant pipe.

The waterproof tube51is in intimate contact with an outer peripheral surface of the end of the second liquid-refrigerant pipe2312adjacent to the first liquid-refrigerant pipe311to cover the entire circumference of the end.

In the air conditioner configured as described above, since the third liquid-refrigerant pipe313is not interposed between the first liquid-refrigerant pipe311and the second liquid-refrigerant pipe2312, it is possible to reduce the number of components. It is therefore possible to simplify a process of manufacturing the air conditioner.

Since the second liquid-refrigerant pipe2312is formed of stainless steel, it is possible to inhibit the progression on rust of the second liquid-refrigerant pipe2312.

Since the waterproof tube51further covers the outer peripheral surface of the end of the second liquid-refrigerant pipe2312adjacent to the first liquid-refrigerant pipe311, it is possible to reduce the possibility that liquid enters the space between the first liquid-refrigerant pipe311and the waterproof tube51from the other end of the first liquid-refrigerant pipe311. It is therefore possible to enhance the effect of preventing the first liquid-refrigerant pipe311from suffering electrolytic corrosion.

Third Example

FIG.9is a front view of a liquid-refrigerant connection pipe31of an air conditioner of a third example of the present disclosure and a peripheral portion of the liquid-refrigerant connection pipe31.

The air conditioner of the third example is similar in configuration to the air conditioner of the first example except that a tubular member61covering the waterproof tube51is provided.

The tubular member61is formed of a heat insulating material (for example, foamed polyester). The tubular member61covers the first liquid-refrigerant pipe311from the upper end of the vertical straight section311ato a tip of the liquid refrigerant union.

Although not illustrated, most of the gas-refrigerant connection pipe32is inserted into the tubular member61in a manner similar to the liquid-refrigerant connection pipe31. Therefore, the tubular member61has an inner diameter set larger than a sum of an outer diameter of the liquid-refrigerant connection pipe31and an outer diameter of the gas-refrigerant connection pipe32.

In the air conditioner configured as described above, since the tubular member61covers the waterproof tube51, it is possible to prevent liquid such as dew condensation water from adhering to the covering member or the waterproof tube51. It is therefore possible to prevent, even if the waterproof tube51becomes cracked, the first liquid-refrigerant pipe311from suffering electrolytic corrosion.

Fourth Example

FIG.10is a front view of a liquid-refrigerant connection pipe4031of an air conditioner of a fourth example of the present disclosure and a peripheral portion of the liquid-refrigerant connection pipe4031.

The air conditioner of the fourth example is similar in configuration to the air conditioner of the first example except that the liquid-refrigerant connection pipe4031formed of aluminum or an aluminum alloy is provided. The liquid-refrigerant connection pipe4031is an example of the connection pipe.

The liquid-refrigerant connection pipe4031includes a first liquid-refrigerant pipe4311formed of two pipe members joined together.

More specifically, the first liquid-refrigerant pipe4311includes a curved section4311dlocated between the indoor heat exchanger15and the vertical straight section311a. A joint portion14311dof the curved section4311dis an end of the curved section4311dadjacent to the second liquid-refrigerant pipe312and is a portion of the curved section4311denlarged in diameter. The upper end of the vertical straight section311ais inserted into and fixed to the joint portion14311dby brazing.

In the air conditioner configured as described above, since the liquid-refrigerant connection pipe4031is provided with the joint portion14311d, it is possible to insert the upper end of the vertical straight section311ainto the waterproof tube51before the upper end of the vertical straight section311ais brazed to the joint portion14311dand before the waterproof tube51is subjected to heat shrinkage. It is therefore possible to make the attachment of the waterproof tube51easy.

The joint portion14311dis provided at the end of the curved section4311dadjacent to the second liquid-refrigerant pipe312in the fourth example, or alternatively, may be provided not at the end of the curved section4311dadjacent to the second liquid-refrigerant pipe312but at the upper end of the vertical straight section311a.

REFERENCE SIGNS LIST