JP7315864B2 - Pressure reducing valve, heat exchanger, air conditioner, and method for manufacturing heat exchanger - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to a pressure reducing valve, a heat exchanger, an air conditioner, and a method for manufacturing the heat exchanger.

In heat exchangers used in air conditioners, aluminum heat transfer tubes, refrigerant tubes, and the like are being used because the price of copper, which is a raw material, continues to rise. Also, in order to enable reheat dehumidification, heat exchangers equipped with dehumidification valves are being developed.

Patent Document 1 describes that when a solenoid valve is attached to a heat exchanger, the joint pipe of the solenoid valve is made of stainless steel to prevent electrolytic corrosion at the connection point between the joint pipe and the aluminum refrigerant pipe. .

JP 2013-185790 A

However, in the configuration of Patent Document 1, due to the low thermal conductivity of stainless steel, when the joint pipe and the refrigerant pipe are joined by brazing, it is difficult to uniformly heat the brazing part in burner brazing. is difficult, and there is a possibility that poor bonding may occur.

An object of the present disclosure is to suppress the occurrence of defective joints when brazing an aluminum refrigerant pipe to a joint pipe made of a metal other than aluminum in a pressure reducing valve.

A first aspect of the present disclosure includes a valve body (51), a joint pipe (52) having one end connected to the valve body (51), and a joint pipe (52) connected to the other end by welding. A pressure reducing valve (50) comprising a connection member (53). The joint pipe (52) is made of a metal other than aluminum. The connection member (53) is made of aluminum or an aluminum alloy.

In the first mode, the connection member (53) made of aluminum is welded to the tip of the joint pipe (52) made of a metal other than aluminum. Therefore, when connecting the aluminum refrigerant pipe (36) to the joint pipe (52), the aluminum connecting member (53) can be brazed to the refrigerant pipe (36). Therefore, the brazing property is improved, so that the occurrence of joint failure can be suppressed.

According to a second aspect of the present disclosure, in the first aspect, the connecting member (53) has a length of 5 mm or less in the axial direction of the joint pipe (52).

In the second aspect, the brazed portion between the connection member (53) and the refrigerant pipe (36) can be shortened.

According to a third aspect of the present disclosure, in the first or second aspect, the distance from the connecting member (53) to the valve body (51) is 15 mm or more.

In the third aspect, heat generated when welding the connection member (53) to the joint pipe (52) hardly affects the valve body (51).

According to a fourth aspect of the present disclosure, in any one of the first to third aspects, the joint pipe (52) is made of copper or a copper alloy and coated with a coating film.

In the fourth aspect, it is possible to suppress electrolytic corrosion at the joint between the joint pipe (52) and the refrigerant pipe (36).

According to a fifth aspect of the present disclosure, in any one of the first to third aspects, the joint pipe (52) is made of stainless steel.

In the fifth aspect, it is possible to suppress electrolytic corrosion at the joint between the joint pipe (52) and the refrigerant pipe (36).

A sixth aspect of the present disclosure is the pressure reducing valve (50) of any one of the first to fifth aspects, a heat transfer tube (35) made of aluminum or an aluminum alloy, and the heat transfer tube (35) A heat exchanger (30) comprising a refrigerant pipe (36) made of aluminum or an aluminum alloy connected to the refrigerant pipe (36), wherein the refrigerant pipe (36) is connected to the connecting member (53) of the pressure reducing valve (50). brazed to.

In the sixth aspect, in the pressure reducing valve (50), the connecting member (53) made of aluminum is welded to the tip of the joint pipe (52) made of non-aluminum. Therefore, the aluminum refrigerant pipe (36) can be brazed to the aluminum connecting member (53). Therefore, the brazing property is improved, so that the occurrence of joint failure can be suppressed. This improves the reliability of the heat exchanger (30).

According to a seventh aspect of the present disclosure, in the sixth aspect, a plurality of the refrigerant pipes (36) are provided, and the plurality of refrigerant pipes (36) are connected to the pressure reducing valve (50) via a flow dividing portion (37). connected with

In the seventh aspect, by brazing the aluminum-made flow dividing portion (37) to the aluminum-made connecting member (53), it is possible to improve the brazing performance and suppress the occurrence of joint failure.

An eighth aspect of the present disclosure is an air conditioner comprising the heat exchanger (30) of the sixth or seventh aspect.

In the eighth aspect, in the pressure reducing valve (50) provided in the heat exchanger (30), the connecting member (53) made of aluminum is welded to the tip of the joint pipe (52) made of non-aluminum. Therefore, the aluminum refrigerant pipe (36) can be brazed to the aluminum connecting member (53). Therefore, the brazing property is improved and the occurrence of defective joints can be suppressed, thereby improving the reliability of the air conditioner (10).

A ninth aspect of the present disclosure is a method of manufacturing a heat exchanger (30). The heat exchanger (30) includes a pressure reducing valve (50), a heat transfer tube (35) made of aluminum or an aluminum alloy, and a refrigerant connected to the heat transfer tube (35) and made of aluminum or an aluminum alloy. A pipe (36). The pressure reducing valve (50) comprises a valve body (51), a joint pipe (52) one end of which is connected to the valve body (51), and a connection which is welded to the other end of the joint pipe (52). A member (53), wherein the joint pipe (52) is made of a metal other than aluminum, and the connection member (53) is made of aluminum or an aluminum alloy. In the method for manufacturing the heat exchanger (30), the refrigerant pipe (36) and the connection member (53) of the pressure reducing valve (50) are connected by brazing.

In the ninth aspect, in the pressure reducing valve (50), the connecting member (53) made of aluminum is welded to the tip of the joint pipe (52) made of non-aluminum. Therefore, by brazing the aluminum refrigerant pipe (36) to the aluminum connecting member (53), brazing performance is improved. Therefore, the occurrence of defective joints can be suppressed, and the reliability of the heat exchanger (30) is improved.

FIG. 1 is a piping system diagram showing a schematic configuration of an air conditioner according to an embodiment. FIG. 2 is a diagram showing the flow of refrigerant in the heat exchanger according to the embodiment. FIG. 3 is a perspective view showing how the pressure reducing valve and the refrigerant pipe are connected according to the embodiment. FIG. 4 is a schematic diagram showing a schematic configuration of the pressure reducing valve according to the embodiment. FIG. 5 is a cross-sectional view showing an example of a connecting member provided in the pressure reducing valve according to the embodiment. FIG. 6 is a perspective view showing a state in which the pressure reducing valve and the refrigerant pipe are connected to each other via the branching portion in the modified example.

(embodiment)
Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. It should be noted that the present disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of the present disclosure. Since each drawing is for conceptually explaining the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary to facilitate understanding.

<Air conditioner>
As shown in FIG. 1, the air conditioner (10) of this embodiment includes an outdoor unit (11) and an indoor unit (13). The outdoor unit (11) houses an outdoor circuit (20) and an outdoor fan (12). The indoor unit (13) houses an indoor heat exchanger (30) and an indoor fan (14). The outdoor unit (11) and the indoor unit (13) are connected to each other via a liquid side connecting pipe (16) and a gas side connecting pipe (17) to form a refrigerant circuit (15). That is, the air conditioner (10) is a refrigeration cycle device.

[Outdoor unit]
The outdoor circuit (20) is provided with a compressor (25), a four-way switching valve (26), an outdoor heat exchanger (27), and an expansion valve (28). In the outdoor circuit (20), the discharge pipe and suction pipe of the compressor (25) are connected to the four-way switching valve (26). A gas side end (22) of the outdoor circuit (20) is connected to a four-way switching valve (26). In the outdoor circuit (20), an expansion valve (28) and an outdoor heat exchanger (27) are arranged in order from the liquid side end (21) of the outdoor circuit (20) toward the four-way switching valve (26).

One end of a liquid side connecting pipe (16) is connected to the liquid side end (21) of the outdoor circuit (20), and a gas side connecting pipe (17) is connected to the gas side end (22) of the outdoor circuit (20). is connected.

The compressor (25) is a fully hermetic compressor. The outdoor heat exchanger (27) is a heat exchanger that exchanges heat between the refrigerant in the refrigerant circuit (15) and the outdoor air. The expansion valve (28) is a so-called electronic expansion valve. The four-way switching valve (26) is a switching valve for switching between cooling operation and heating operation.

[Indoor unit]
The indoor heat exchanger (30) includes a first unit (31A), a second unit (31B), and a pressure reducing valve (50). The first unit (31A) and the second unit (31B) are connected via a refrigerant pipe (36) provided with a pressure reducing valve (50). The first unit (31A) and the second unit (31B) are so-called cross-fin heat exchangers that exchange heat between the refrigerant in the refrigerant circuit (15) and room air. The pressure reducing valve (50) may be an electrically operated valve or an electromagnetic valve. The pressure reducing valve (50) switches between a fully open state and a reduced opening state. One end of the gas side pipe (33) is connected to the first unit (31A), and one end of the liquid side pipe (32) is connected to the second unit (31B). The other end of the liquid side pipe (32) is connected to the other end of the liquid side connecting pipe (16), and the other end of the gas side pipe (33) is connected to the other end of the gas side connecting pipe (17). be done.

[Operation behavior of air conditioner]
The air conditioner (10) selectively performs cooling operation and heating operation. In each of the cooling operation and the heating operation, the air conditioner (10) performs a refrigeration cycle by circulating the refrigerant in the refrigerant circuit (15).

In cooling operation, the four-way switching valve (26) is in the state indicated by solid lines in FIG. 1, the outdoor heat exchanger (27) functions as a condenser, and the indoor heat exchanger (30) functions as an evaporator. Specifically, by reducing the opening of the expansion valve (28) and fully opening the pressure reducing valve (50), the first unit (31A) and the second unit (31B) function as evaporators. The indoor unit (13) cools the sucked indoor air in the first unit (31A) and the second unit (31B) of the indoor heat exchanger (30), and blows the cooled indoor air indoors.

In heating operation, the four-way switching valve (26) is in the state indicated by the dashed line in FIG. 1, the indoor heat exchanger (30) functions as a condenser, and the outdoor heat exchanger (27) functions as an evaporator. Specifically, by reducing the opening of the expansion valve (28) and fully opening the pressure reducing valve (50), the first unit (31A) and the second unit (31B) function as condensers. The indoor unit (13) heats the sucked indoor air in the first unit (31A) and the second unit (31B) of the indoor heat exchanger (30), and blows out the heated indoor air into the room.

In reheat dehumidification operation, the four-way switching valve (26) is in the state indicated by the solid line in FIG. function as Specifically, by fully opening the expansion valve (28) and reducing the degree of opening of the pressure reducing valve (50), the first unit (31A) functions as an evaporator and the second unit (31B) functions as a condenser. function as The indoor unit (13) dehumidifies the sucked indoor air in the first unit (31A) of the indoor heat exchanger (30) and blows out the dehumidified indoor air indoors.

<Heat exchanger>
The indoor heat exchanger (30) (hereinafter sometimes simply referred to as the heat exchanger (30)) will be described with reference to FIG. In FIG. 2 , hollow arrows indicate the flow of air, solid arrows indicate the flow of refrigerant during heating, and broken arrows indicate the flow of refrigerant during cooling.

In the heat exchanger (30) shown in FIG. 2, the first unit (31A) and the second unit (31B) each have a plurality of fins (34) and a plurality of heat transfer tubes (35). The plurality of heat transfer tubes (35) have grooves on their inner surfaces. Each of the first unit (31A) and the second unit (31B) has a heat exchange section in which a plurality of heat transfer tubes (35) are inserted through a plurality of fins (34). It is configured by providing a plurality of rows in the flow direction. The first unit (31A) and the second unit (31B) are connected via a refrigerant pipe (36) provided with a pressure reducing valve (50). The pressure reducing valve (50) is provided to allow the first unit (31A) to function as an evaporator and the second unit (31B) to function as a condenser during reheat dehumidification.

The heat transfer tube (35) forms part of the refrigerant circuit (15), and refrigerant flows through the heat transfer tube (35). The heat transfer tube (35) transfers the heat of the refrigerant flowing inside to the air flowing outside through the fins (34). As a result, the heat transfer area, which is the contact surface with the air, is increased, promoting heat exchange between the refrigerant and the air.

The fins (34), heat transfer tubes (35), and refrigerant pipes (36) are made of aluminum or an aluminum alloy.

<Reducing valve>
The pressure reducing valve (50), as shown in FIG. 3, has a valve body (51) and a joint pipe (52) one end of which is connected to the valve body (51). The joint pipe (52) may be provided integrally with the valve body (51). Alternatively, a joint pipe (52) formed separately from the valve body (51) may be attached to the valve body (51) by welding or the like.

The joint pipe (52) includes a first joint pipe (52A) and a second joint pipe (52B). The first joint pipe (52A) is connected to one of the first unit (31A) or the second unit (31B) through the refrigerant pipe (36), and the second joint pipe (52B) is connected to the second unit through the refrigerant pipe (36). It is connected to the other of the 1st unit (31A) or the 2nd unit (31B).

The joint pipe (52) is made of metal other than aluminum. Specifically, the metal other than aluminum is copper or a copper alloy, or stainless steel. When the joint pipe (52) is made of copper or a copper alloy, the surface of the joint pipe (52) is coated with a coating film made of, for example, an anti-corrosion coating material.

<Connection between pressure reducing valve and refrigerant pipe>
FIG. 4 shows a schematic configuration when the pressure reducing valve (50) is composed of an electromagnetic valve. In the pressure reducing valve (50) shown in FIG. 4, the valve body (51) mainly includes a refrigerant flow path (51a), a valve body (51b), a movable core (51c), and a fixed core (51d). , and an electromagnetic coil (51e). The refrigerant flow path (51a) connects the pipelines of the first joint pipe (52A) and the second joint pipe (52B). The valve body (51b) opens and closes the refrigerant channel (51a). The movable core (51c) is configured to be movable together with the valve body (51b). The movable core (51c) is composed of an iron core. The fixed core (51d) is fixedly arranged on the opposite side of the valve body (51b) with the movable core (51c) interposed therebetween. The electromagnetic coil (51e) is arranged to surround the movable core (51c) and the fixed core (51d), and controls the movement of the movable core (51c).

Specifically, the movable core (51c) is urged upward (toward the fixed core (51d)) by a coil spring (not shown), and when the electromagnetic coil (51e) is de-energized, the movable core (51c) moves toward the valve. It is positioned upward together with the body (51b) and opens. When the electromagnetic coil (51e) is energized, an electromagnetic force is generated, and the electromagnetic force moves the movable core (51c) downward together with the valve body (51b), causing the valve body (51b) to move to the valve seat (51f). Sit down and close the valve. A minute groove (not shown) is provided in the valve seat (51f), and the refrigerant flows through this groove when the valve is closed.

As shown in FIG. 4, the pressure reducing valve (50) has a connection member (53) at the tip of the joint pipe (52) (the end opposite to the valve body (51a)). The refrigerant pipe (36) is brazed to. The connection member (53) is made of aluminum or an aluminum alloy and welded to the joint pipe (52).

As shown in FIG. 5, the connecting member (53) may be bush-shaped and inserted into the distal end of the joint pipe (52). FIG. 5(a) shows a cross-sectional configuration of the connecting member (53) before being inserted into the joint pipe (52), and FIG. ) and its peripheral cross-sectional configuration are shown, respectively. When the connecting member (53) shown in FIG. 5(a) is used, the refrigerant pipe (36) is inserted into the connecting member (53) as shown in FIG. 5(b). ).

The length of the connecting member (53) (the length along the axial direction of the joint pipe (52)) may be about 5 mm or less. The distance from the connection member (53) to the valve body (51) (valve body (51a)) may be about 15 mm or more.

<Method for manufacturing heat exchanger>
When manufacturing the heat exchanger (30), first, the pressure reducing valve (50) of the present embodiment is prepared. The pressure reducing valve (50) includes a valve body (51), a joint pipe (52) having one end connected to the valve body (51), and a connection member (53) welded to the other end of the joint pipe (52). ), the joint pipe (52) is made of a metal other than aluminum, and the connecting member (53) is made of aluminum or an aluminum alloy. The pressure reducing valve (50) may be purchased from a vendor or manufactured in-house.

Next, as shown in FIGS. 4 and 5, the refrigerant pipe (36) and the connection member (53) of the pressure reducing valve (50) are connected by brazing. As a result, the aluminum refrigerant pipe (36) is brazed to the aluminum connection member (53), thereby improving the brazeability.

<Features of Embodiment>
The pressure reducing valve (50) of this embodiment includes a valve body (51), a joint pipe (52) one end of which is connected to the valve body (51), and the other end of the joint pipe (52) connected by welding. A connecting member (53). The joint pipe (52) is made of a metal other than aluminum, and the connection member (53) is made of aluminum or an aluminum alloy.

According to the pressure reducing valve (50) of the present embodiment, when connecting the aluminum refrigerant pipe (36) to the joint pipe (52), the aluminum connection member (53) is brazed to the refrigerant pipe (36). be able to. Therefore, the brazing property is improved, so that the occurrence of joint failure can be suppressed. This improves the reliability of the pressure reducing valve (50).

Further, according to the pressure reducing valve (50) of the present embodiment, the connection member (53) can prevent contact between the joint pipe (52) made of dissimilar metals and the refrigerant pipe (36). Corrosion caused by

In addition, according to the pressure reducing valve (50) of the present embodiment, the aluminum refrigerant pipe (36) can be joined to various forms by, for example, burner (flame) brazing, so joining can be performed at low cost. can.

Further, according to the pressure reducing valve (50) of the present embodiment, the aluminum connecting member (53) is joined to the joint pipe (52) by welding without using brazing material. Therefore, when the aluminum refrigerant pipe (36) is brazed to the connecting member (53), remelting of the joint between the connecting member (53) and the joint pipe (52) can be suppressed.

On the other hand, if a valve having a copper joint pipe is attached to an aluminum refrigerant pipe as in the prior art, corrosion due to contact between dissimilar metals becomes a problem. Further, as disclosed in Patent Document 1, when a valve having a stainless steel joint pipe is attached to an aluminum refrigerant pipe, if aluminum brazing material is applied to the joint pipe, the application of the brazing material to the valve cost. Furthermore, joining aluminum refrigerant pipes and stainless steel joint pipes is not easy because these are joints of dissimilar metals. Specifically, stainless steel has a low thermal conductivity, and it is difficult to uniformly heat the brazed portion with a burner. Moreover, even if high-frequency brazing is performed, since the refrigerant pipe has a complicated shape, there is a possibility that a circular high-frequency coil cannot be installed at the brazed portion. Furthermore, when furnace brazing is performed, the heat may damage the valve.

In addition, in the pressure reducing valve (50) of the present embodiment, the length of the connection member (53) (the length of the joint pipe (52) in the pipe axis direction) may be 5 mm or less. By doing so, the brazed portion between the connection member (53) and the refrigerant pipe (36) can be shortened.

Further, in the pressure reducing valve (50) of the present embodiment, the distance from the connecting member (53) to the valve body (51) may be 15 mm or more. With this configuration, the valve body (51) is less likely to be affected by heat generated when the connecting member (53) is welded to the joint pipe (52).

Further, in the pressure reducing valve (50) of the present embodiment, the joint pipe (52) may be made of copper or a copper alloy and coated with a coating film. In this way, electrolytic corrosion at the joint between the joint pipe (52) and the refrigerant pipe (36) can be suppressed.

Further, in the pressure reducing valve (50) of the present embodiment, the joint pipe (52) may be made of stainless steel. In this way, electrolytic corrosion at the joint between the joint pipe (52) and the refrigerant pipe (36) can be suppressed.

The heat exchanger (30) of the present embodiment includes a pressure reducing valve (50), a heat transfer tube (35) made of aluminum or an aluminum alloy, and a heat transfer tube (35) connected to the heat transfer tube (35) and made of aluminum or an aluminum alloy. The refrigerant pipe (36) is brazed to the connection member (53) of the pressure reducing valve (50).

According to the heat exchanger (30) of the present embodiment, the aluminum connection member (53) is welded to the tip of the non-aluminum joint pipe (52) in the pressure reducing valve (50). Therefore, the aluminum refrigerant pipe (36) can be brazed to the aluminum connecting member (53). Therefore, the brazing property is improved, so that the occurrence of joint failure can be suppressed. This improves the reliability of the heat exchanger (30).

The air conditioner (10) of this embodiment includes a heat exchanger (30).

According to the air conditioner (10) of the present embodiment, in the pressure reducing valve (50) provided in the heat exchanger (30), the connecting member (53) made of aluminum is attached to the tip of the joint pipe (52) made of non-aluminum. is welded. Therefore, the aluminum refrigerant pipe (36) can be brazed to the aluminum connection member (53). Therefore, the brazing property is improved and the occurrence of defective joints can be suppressed, thereby improving the reliability of the air conditioner (10).

In the method of manufacturing the heat exchanger (30) of the present embodiment, the refrigerant pipe (36) and the connection member (53) of the pressure reducing valve (50) are connected by brazing.

According to the method for manufacturing the heat exchanger (30) of the present embodiment, the aluminum connection member (53) is welded to the tip of the non-aluminum joint pipe (52) in the pressure reducing valve (50). Therefore, by brazing the aluminum refrigerant pipe (36) to the aluminum connecting member (53), brazing performance is improved. Therefore, the occurrence of defective joints can be suppressed, and the reliability of the heat exchanger (30) is improved.

(Other embodiments)
In the above-described embodiment, the connection member (53) is formed in a bush shape and inserted into the tip of the joint pipe (52). The installation form is not particularly limited.

Further, in the above embodiment, one refrigerant pipe (36) is connected to one joint pipe (52), but instead of this, as shown in FIG. , a plurality of refrigerant pipes (36) may be connected via the flow dividing portion (37). In FIG. 6, the same reference numerals are given to the same components as in the embodiment shown in FIG. The flow dividing portion (37) is made of the same material as the refrigerant pipe (36), specifically aluminum or an aluminum alloy. In this way, by brazing the aluminum flow dividing portion (37) to the aluminum connecting member (53) of the pressure reducing valve (50), the brazing performance is improved and the connection is made in the same manner as in the above-described embodiment. It is possible to suppress the occurrence of defects. The flow dividing portion (37) and each refrigerant pipe (36) are joined by brazing.

Further, in the above-described embodiment, the case where the heat exchanger (30) is applied to the air conditioner (10), which is a refrigerating cycle device, was exemplified, but it goes without saying that the use of the heat exchanger (30) is not particularly limited. .

Further, in the above embodiment, the case where the pressure reducing valve (50) is applied to the heat exchanger (30) was illustrated, but it goes without saying that the use of the pressure reducing valve (50) is not particularly limited.

Although the embodiments have been described above, it will be appreciated that various changes in form and detail may be made without departing from the spirit and scope of the claims. Also, the above embodiments may be combined or replaced as appropriate. Furthermore, the descriptions of "first", "second", ... described above are used to distinguish the words and phrases to which these descriptions are given, and even limit the number and order of the words and phrases. isn't it.

INDUSTRIAL APPLICABILITY As described above, the present disclosure is useful for pressure reducing valves, heat exchangers, air conditioners, and heat exchanger manufacturing methods.

REFERENCE SIGNS LIST 10 Air conditioner 30 Heat exchanger 35 Heat transfer tube 36 Refrigerant pipe 37 Diversion part 50 Pressure reducing valve 51 Valve main body 52 Joint pipe 53 Connection member

Claims (9)

a valve body (51);
a joint pipe (52) one end of which is connected to the valve body (51);
a connection member (53) that is welded to the other end of the joint pipe (52) and that is brazed to the refrigerant pipe (36) made of aluminum or an aluminum alloy ,
The joint pipe (52) is made of a metal other than aluminum,
The connection member (53) is a pressure reducing valve made of aluminum or an aluminum alloy. In the pressure reducing valve (50) of claim 1,
A pressure reducing valve, wherein the connecting member (53) has a length of 5 mm or less in the axial direction of the joint pipe (52). In the pressure reducing valve (50) according to claim 1 or 2,
A pressure reducing valve, wherein a distance from the connecting member (53) to the valve body (51) is 15 mm or more. In the pressure reducing valve (50) according to any one of claims 1 to 3,
A pressure reducing valve in which the joint pipe (52) is made of copper or a copper alloy and coated with a coating film. In the pressure reducing valve (50) according to any one of claims 1 to 3,
The joint pipe (52) is a pressure reducing valve made of stainless steel. a pressure reducing valve (50) according to any one of claims 1 to 5;
a heat transfer tube (35) made of aluminum or an aluminum alloy;
A refrigerant pipe (36) made of aluminum or an aluminum alloy connected to the heat transfer pipe (35),
The refrigerant pipe (36) is a heat exchanger brazed to the connecting member (53) of the pressure reducing valve (50). The heat exchanger (30) of claim 6, wherein
A plurality of the refrigerant pipes (36) are provided,
A heat exchanger in which the plurality of refrigerant pipes (36) are connected to the pressure reducing valve (50) via a branch portion (37). An air conditioner comprising the heat exchanger (30) according to claim 6 or 7. A method for manufacturing a heat exchanger (30), comprising:
The heat exchanger (30) is
a pressure reducing valve (50);
a heat transfer tube (35) made of aluminum or an aluminum alloy;
A refrigerant pipe (36) made of aluminum or an aluminum alloy connected to the heat transfer pipe (35),
The pressure reducing valve (50)
a valve body (51);
a joint pipe (52) one end of which is connected to the valve body (51);
a connecting member (53) welded to the other end of the joint pipe (52),
The joint pipe (52) is made of a metal other than aluminum,
The connection member (53) is made of aluminum or an aluminum alloy,
connecting the refrigerant pipe (36) and the connection member (53) of the pressure reducing valve (50) by brazing;
A method for manufacturing a heat exchanger.