JP2023041799A - Refrigerating devices and refrigerant pipes of refrigerating devices - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide refrigerant pipes of refrigerating devices that facilitate work for connection to narrow pipes.

SOLUTION: Refrigerant pipes R1, R2, R3, and R4 of refrigerating devices A and B comprise: stainless-steel first pipes 23, 60, and 70 inside which a refrigerant flows; joint pipes 40, 61, and 71 provided in outer peripheral surfaces of the first pipes 23, 60, and 70, and made of a material different from stainless steel; and second pipes 41, 50, 51, 62, 63, 72, and 73 having smaller pipe diameters than those of the first pipes 23, 60, and 70, and connected to the outer peripheral surfaces of the first pipes 23, 60, and 70 via the joint pipes 40, 61, and 71. Connected surfaces 51b, 63a, and 73a of the second pipes 41, 50, 51, 62, 63, 72, and 73 connected to the joint pipes 40, 61, and 71 are made of the same material as that of the joint pipes 40, 61, and 71.

SELECTED DRAWING: Figure 8

COPYRIGHT: (C)2023,JPO&INPIT

Description

TECHNICAL FIELD The present disclosure relates to a refrigeration system and refrigerant piping for the refrigeration system.

2. Description of the Related Art Conventionally, many copper pipes have been used as refrigerant pipes in refrigeration equipment such as air conditioners or air conditioners. Also, thin tubes to which service ports, pressure sensors, etc. are connected are often made of copper. The connection between such a thin tube and a refrigerant pipe that communicates with the thin tube has hitherto been performed by hand brazing.

Copper pipes have the advantage of being relatively easy to process, but the material cost is high, so it is conceivable to use refrigerant pipes made of relatively inexpensive stainless steel (see, for example, Patent Document 1).

JP 2010-151327 A

However, if the refrigerant pipes of the refrigerating device are made of stainless steel, the connection work between the refrigerant pipes and the fine tubes becomes complicated.
An object of the present disclosure is to provide a refrigerating device and a refrigerant pipe of the refrigerating device that facilitates connection work with thin tubes.

The refrigerant pipe of the refrigeration system of the present disclosure (hereinafter also simply referred to as “refrigerant pipe”) is
(1) A first pipe made of stainless steel in which a refrigerant flows;
a joint pipe provided on the outer peripheral surface of the first pipe and made of a material different from stainless steel;
A second pipe having a pipe diameter smaller than that of the first pipe and connected to the outer peripheral surface of the first pipe via the joint pipe, wherein the surface to be connected to the joint pipe of the second pipe is the It is made of the same material as the joint pipe.

In the refrigerant pipe of the present disclosure, the joint pipe provided on the outer peripheral surface of the first pipe made of stainless steel is made of a material different from stainless steel, and the second pipe is connected to the outer peripheral surface of the first pipe via this joint pipe. The surface of the pipe to be connected to the joint pipe is made of the same material as the joint pipe. Therefore, it is possible to easily connect the second pipe, which is a thin pipe, to the first pipe made of stainless steel without brazing the stainless steel pipe, which involves complicated work. In this specification, "same material" means that the main components are the same, and is not limited to the case where the constituent components are the same. For example, copper and a copper alloy containing copper as the main component are the same material, and an aluminum alloy containing aluminum as the main component and another aluminum alloy containing aluminum as the main component are the same material. A copper alloy is an alloy in which other metals are added to copper as the main component to improve the properties of copper. Aluminum alloys are alloys in which other metals are added to aluminum as the main component to improve the properties of aluminum. In this specification, "copper" means "pure copper" containing 99.9% by weight or more of copper as the main component, and "aluminum" means 99.9% by weight of aluminum as the main component. It is "pure aluminum" including the above.

(2) In the refrigerant pipe of (1) above, the joint pipe is provided in the first pipe in a direction perpendicular to the axial direction of the first pipe.

(3) In the refrigerant pipe of (1) or (2), the connecting surfaces of the joint pipe and the second pipe are made of copper or a copper alloy. Since the joint pipe and the second pipe can be connected by hand brazing, the second pipe can be easily connected to the first pipe made of stainless steel.

(4) In the refrigerant pipes of (1) to (3) above, the second pipe has a pipe body made of stainless steel and a connection portion provided at an end of the pipe body, and the connection portion is The connected surface is included. A second pipe is connected to the outer peripheral surface of the first pipe via a joint pipe made of a material different from stainless steel, and the connected surface of the connection portion provided on the stainless steel pipe body of the second pipe is the joint pipe. It is the same material as Therefore, the stainless steel pipe does not need to be brazed, which involves complicated work, and the second pipe can be easily connected to the stainless steel first pipe.

(5) In the refrigerant pipe of (4) above, the pipe body has a second large diameter portion and a second small diameter portion smaller in diameter than the second large diameter portion, and the connection portion has the second small diameter portion. It can be a pipe provided on the outer peripheral surface of the part. The outer peripheral surface of the pipe provided on the outer peripheral surface of the second small diameter portion of the pipe main body constitutes the connected surface. The surface to be connected and the joint pipe are made of the same material, and can be easily connected by a conventional method such as manual brazing.

(6) In the refrigerant pipes of (1) to (3) above, the second pipe may be a copper pipe. The outer peripheral surface of the copper pipe forming the connecting surface and the joint pipe made of copper or copper alloy can be easily connected by a conventional method such as manual brazing.

(7) In the refrigerant pipes of (1) to (6) above, it is desirable that a first positioning mechanism for determining the position of the joint pipe with respect to the first pipe is provided on the outer peripheral surface of the joint pipe. The position of the joint pipe with respect to the first pipe can be easily determined by the first positioning mechanism.

(8) In the refrigerant pipes of (1) to (7), it is desirable that the joint pipe or the second pipe has a second positioning mechanism for positioning the second pipe with respect to the joint pipe. The position of the joint pipe with respect to the second pipe can be easily determined by the second positioning mechanism.

(9) In the refrigerant pipes of (1) to (8), it is desirable that the second pipe overlaps the first pipe in the radial direction of the second pipe. When the second pipe overlaps the first pipe in the pipe radial direction of the second pipe, the second pipe is connected to the first pipe via the joint pipe, so the connection between the joint pipe and the first pipe Then, the second pipe and the joint pipe exist in the radial direction of the second pipe. Due to the presence of the second pipe, the strength of the connecting portion between the joint pipe and the first pipe can be improved compared to the case where only the joint pipe exists.

(10) In the refrigerant pipe of (4) or (5), it is preferable that the pipe main body of the second pipe overlaps the first pipe in the radial direction of the second pipe. When the pipe main body of the second pipe overlaps the first pipe in the radial direction of the second pipe, the pipe main body of the second pipe is connected to the first pipe via the joint pipe. At the connecting portion with the first pipe, the pipe main body and the joint pipe of the second pipe are present in the radial direction of the second pipe. In addition, the main body of the pipe is made of stainless steel and has a higher rigidity than a copper pipe. Due to the presence of the pipe main body of the second pipe, compared to the case where only the joint pipe exists, not only the strength of the connection part between the joint pipe and the first pipe, but also the strength of the first pipe and the second pipe via the joint pipe The strength of the connection of piping can be improved.

(11) The refrigeration apparatus of the present disclosure includes a refrigerant circuit including a plurality of element parts and refrigerant pipes connecting the plurality of element parts,
Refrigerant piping connecting the plurality of element parts includes the refrigerant piping according to any one of (1) to (10).

1 is a schematic configuration diagram of one embodiment of a refrigeration apparatus of the present disclosure; FIG. 3 is a schematic configuration diagram of another embodiment of a refrigeration system of the present disclosure; FIG. 1 is a front explanatory view of an example of a switching mechanism including refrigerant pipes according to the first embodiment of the present disclosure; FIG. 4 is a perspective explanatory view around a compressor including the switching mechanism shown in FIG. 3; FIG. 1 is a cross-sectional explanatory diagram of a refrigerant pipe according to a first embodiment of the present disclosure; FIG. FIG. 6 is an explanatory diagram of thin tubes of the refrigerant pipe shown in FIG. 5; FIG. 6 is an explanatory diagram of a joint of the refrigerant pipe shown in FIG. 5; FIG. 5 is a cross-sectional explanatory diagram of a refrigerant pipe according to a second embodiment of the present disclosure; FIG. 7 is a cross-sectional explanatory diagram of a refrigerant pipe according to a third embodiment of the present disclosure; FIG. 10 is an explanatory diagram of a joint of the refrigerant pipe shown in FIG. 9; FIG. 11 is a cross-sectional explanatory diagram of a refrigerant pipe according to a fourth embodiment of the present disclosure; FIG. 12 is an explanatory diagram of a joint of the refrigerant pipe shown in FIG. 11; FIG. 12 is a cross-sectional explanatory view of a modification of the refrigerant pipe shown in FIG. 11; FIG. 13 is a cross-sectional explanatory view of a modification of the joint shown in FIG. 12;

Hereinafter, the refrigerating apparatus of the present disclosure and the refrigerant piping of the refrigerating apparatus will be described in detail with reference to the accompanying drawings. The present disclosure is not limited to these examples, but is indicated by the scope of the claims, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

[Air conditioner A]
FIG. 1 is a schematic configuration diagram of an air conditioner or air conditioner A that is a refrigerating device, according to an embodiment of the present disclosure. The air conditioner A adjusts the temperature and humidity in the air-conditioned room using a vapor compression refrigeration cycle. An air conditioner A includes an indoor unit 1 installed indoors and an outdoor unit 2 installed outdoors. The indoor unit 1 and the outdoor unit 2 are connected to each other by refrigerant pipes 8 .

The air conditioner A includes a refrigerant circuit 3 that performs a vapor compression refrigeration cycle. The refrigerant circuit 3 includes a plurality of element parts and refrigerant pipes 8 connecting the plurality of element parts.

The refrigerant circuit 3 includes a compressor 4 that compresses a refrigerant to generate a high-temperature and high-pressure gas refrigerant, an indoor heat exchanger 5, an electronic expansion valve 6 that decompresses the refrigerant, an outdoor heat exchanger 7, an accumulator 11, a muffler 15, four A path switching valve 16 and the like are provided, and these are connected by a refrigerant pipe 8 . The compressor 4, the indoor heat exchanger 5, the electronic expansion valve 6, the outdoor heat exchanger 7, the accumulator 11, the muffler 15, the four-way switching valve 16, and the gas shut-off valve and liquid shut-off valve described later constitute the air conditioner A. and is connected to other equipment or parts by refrigerant pipes 8 . In this specification, these devices or parts are also referred to as elemental parts that constitute the refrigeration system.

The compressor 4 compresses the low-pressure gas refrigerant and discharges high-pressure gas refrigerant. The compressor 4 has a suction port or suction portion 4a and a discharge port or discharge portion 4b. The low-pressure gas refrigerant is sucked from the suction portion 4a. The high-pressure gas refrigerant is discharged in the direction of arrow D from the discharge portion 4b. As the compressor 4, for example, various compressors such as a scroll compressor can be adopted. The compressor 4 is fixed to the bottom plate of the casing 2a of the outdoor unit 2 or the like.

The indoor heat exchanger 5 is provided in the indoor unit 1 and exchanges heat between the refrigerant and the indoor air. As the indoor heat exchanger 5, for example, a cross-fin type fin-and-tube heat exchanger or a microchannel heat exchanger can be employed. An indoor fan 9 is provided in the vicinity of the indoor heat exchanger 5 for blowing indoor air to the indoor heat exchanger 5 and sending conditioned air indoors.

The electronic expansion valve 6 is arranged between the outdoor heat exchanger 7 and the indoor heat exchanger 5 in the refrigerant pipe 8 of the refrigerant circuit 3, and expands the inflowing refrigerant to reduce the pressure to a predetermined pressure.

The outdoor heat exchanger 7 exchanges heat between the refrigerant and the outdoor air. The outdoor heat exchanger 7 can employ, for example, a cross-fin type fin-and-tube heat exchanger or a microchannel heat exchanger. An outdoor fan 10 for blowing outdoor air to the outdoor heat exchanger 7 is provided near the outdoor heat exchanger 7 .

In this embodiment, an accumulator 11 is provided in the refrigerant pipe 8a on the suction side of the compressor 4. As shown in FIG. The accumulator 11 is fixed to the bottom plate of the casing 2a of the outdoor unit 2 or the like. A muffler 15 for reducing pressure pulsation of the refrigerant discharged from the compressor 4 is provided in the refrigerant pipe 8 b on the discharge side of the compressor 4 .

The refrigerant pipe 8 is provided with a four-way switching valve 16, a gas shutoff valve 17, and a liquid shutoff valve 18 for switching refrigerant flow paths. By switching the four-way switching valve 16, the flow of the refrigerant is reversed, the refrigerant discharged from the compressor 4 is switched between the outdoor heat exchanger 7 and the indoor heat exchanger 5, and the cooling operation and the heating operation are switched. It is possible to switch.

The gas shutoff valve 17 and the liquid shutoff valve 18 open or close the path of the refrigerant. Opening and closing are performed manually, for example. The gas shutoff valve 17 and the liquid shutoff valve 18 are closed, for example, when the air conditioner A is installed, in order to prevent the refrigerant sealed in the outdoor unit 2 from leaking to the outside. On the other hand, the gas shutoff valve 17 and the liquid shutoff valve 18 are opened when the air conditioner A is in use.

During the heating operation of the air conditioner A, the four-way switching valve 16 is switched as indicated by the solid line to flow the refrigerant in the direction indicated by the solid line arrow. As a result, the high-pressure gas refrigerant discharged from the compressor 4 in the direction of arrow D passes through the muffler 15 and the four-way switching valve 16, and then passes through the opened gas shut-off valve 17 to enter the indoor heat exchanger 5. to go into. The high-pressure gas refrigerant releases heat in the process of becoming high-pressure liquid refrigerant in the indoor heat exchanger 5 . The high-pressure liquid refrigerant reaches the electronic expansion valve 6 through the opened liquid closing valve 18 and is decompressed by the electronic expansion valve 6 . The depressurized refrigerant reaches the outdoor heat exchanger 7, absorbs heat in the outdoor heat exchanger 7, and becomes a low-pressure gas refrigerant. Low-pressure gas refrigerant is sucked into the compressor 4 through the four-way switching valve 16 and the accumulator 11 . During heating operation, the indoor heat exchanger 5 functions as a radiator, and the outdoor heat exchanger 7 functions as a heat absorber.

On the other hand, during cooling operation, the flow of the refrigerant is reversed by switching the four-way switching valve 16 as indicated by the dotted line, and the refrigerant flows in the direction indicated by the dotted arrow. As a result, the high-pressure gas refrigerant discharged from the compressor 4 in the direction of arrow D enters the outdoor heat exchanger 7 after passing through the muffler 15 and the four-way switching valve 16 . The high-pressure gas refrigerant releases heat in the process of becoming high-pressure liquid refrigerant in the outdoor heat exchanger 7 . The high-pressure liquid refrigerant reaches the electronic expansion valve 6 and is decompressed by the electronic expansion valve 6 . The decompressed refrigerant reaches the indoor heat exchanger 5 through the opened liquid closing valve 18, absorbs heat in the indoor heat exchanger 5, and becomes a low-pressure gas refrigerant. Low-pressure gas refrigerant is sucked into the compressor 4 through the opened gas shutoff valve 17 , four-way switching valve 16 and accumulator 11 . During cooling operation, the indoor heat exchanger 5 functions as a heat absorber, and the outdoor heat exchanger 7 functions as a radiator.

[Air conditioner B]
FIG. 2 is a schematic configuration diagram of an air conditioner or air conditioner B, which is a refrigerating device, according to another embodiment of the present disclosure. The air conditioner B is provided with an oil separator 12 in place of the muffler 15 on the refrigerant pipe 8 b on the discharge side of the compressor 4 . The oil separated by the oil separator 12 is returned to the refrigerant pipe 8 a on the intake side of the compressor 4 via the oil return pipe 14 provided with the valve 13 . The structures other than the oil separator 12, the valve 13 and the oil return pipe 14 are the same as the example shown in FIG. 1, and common structures or elements are given the same numbers. For the sake of simplification, descriptions of common configurations and elements are omitted. In the example shown in FIGS. 1 and 2, one of the muffler 15 and the oil separator 12 is provided in the refrigerant pipe 8b on the discharge side of the compressor 4. It can also be provided in the refrigerant pipe 8b.

[Switching mechanism C]
FIG. 3 is a front explanatory view of the switching mechanism C in the air conditioners A and B according to this embodiment, and FIG. 4 is a perspective explanatory view around the compressor including the switching mechanism C shown in FIG. The switching mechanism C includes refrigerant piping according to an embodiment of the present disclosure, which will be described later.

The switching mechanism C has a four-way switching valve 16 and pipes 21, 22, 23, and 24 connected to four ports or connecting ports of the four-way switching valve 16, respectively. A four-way switching valve 16 including four ports and pipes 21, 22, 23, 24 are made of stainless steel, which has higher rigidity than copper. As stainless steel, for example, SUS304, SUS304L, SUS436L, SUS430, etc. can be used. In this embodiment, the switching mechanism includes not only the four-way switching valve 16 but also the pipes connected to the four ports of the four-way switching valve 16 . In other words, the switching mechanism has a function of switching the refrigerant flow path and can be assembled in advance as a unit or assembly in a factory or the like. The switching mechanism C is connected to connecting portions or connecting pipes provided in component parts such as the compressor 4 and the accumulator 11 by brazing or the like at the site where the outdoor unit 2 is assembled.

The four-way switching valve 16 has a valve body 16a forming an outer shell, and a valve body and the like housed inside the valve body 16a. The valve body 16a is made of stainless steel. The four-way switching valve 16 is formed of short pipes and has four ports, ie, a first port 31, a second port 32, a third port 33 and a fourth port 34, which constitute inlets and outlets of the refrigerant. These first to fourth ports 31 to 34 are made of stainless steel. One ends of pipes 21, 22, 23 and 24 are connected to the first to fourth ports 31 to 34, respectively.
In the installed state of the four-way switching valve 16, the first port 31 faces upward, and the second to fourth ports 32, 33, 34 face downward.

A connection portion 44 made of copper is provided at each end portion 22a, 23a, 24a (the end portion opposite to the side connected to the four-way switching valve 16) of the pipes 22 to 24 made of stainless steel. Moreover, in this embodiment, the muffler 15 is made of stainless steel. The pipe 21 in this embodiment is a pipe for circulating the refrigerant between the four-way switching valve 16 and the compressor 4 via the muffler 15, and connects the first port 31 of the four-way switching valve 16 and the muffler 15. A connecting pipe 21a and a pipe 21b connecting the muffler 15 and the discharge portion 4b of the compressor 4 are provided. After the pipe 21a extends upward from the muffler 15, it is folded back and connected to the first port 31 in a downward posture. An end portion 21c of the pipe 21b (an end portion opposite to the side connected to the muffler 15) is provided with a connection portion 44 made of copper, like the pipes 22 to 24 described above.

The pipe 22 connects the second port 32 of the four-way switching valve 16 and the connection pipe 11 a on the inlet side of the accumulator 11 . A pipe 22 connected to a connecting pipe 11a on the inlet side of the accumulator 11 extends upward, folds back and extends downward, then folds back again and is connected to the second port 32 in an upward posture. One end of a refrigerant pipe 38 is connected to a connection pipe (not shown) on the outlet side of the accumulator 11 , and the other end of the refrigerant pipe 38 is connected to the suction portion of the compressor 4 . The refrigerant pipe 38 is also made of stainless steel. As shown in FIG. 4, the compressor 4 in this embodiment includes an auxiliary accumulator 4d integrated with a compressor main body 4c. It is functioning.

The pipe 23 circulates the refrigerant between the gas header (not shown) of the outdoor heat exchanger 7 and the third port 33 of the four-way switching valve 16 . Further, the pipe 24 connects the gas shutoff valve 17 and the fourth port 34 of the four-way switching valve 16 .

In the switching mechanism C shown in FIG. 3, the connection between stainless steel and the connection between stainless steel and copper are both performed by furnace brazing. In this embodiment, the four-way switching valve 16, the muffler 15, the pipes 21, 22, 23, and 24, and the entire switching mechanism C, which is temporarily assembled with a copper joint 40 described later, are put into the furnace, and each connecting portion is simultaneously connected to the furnace. Brazed inside.

[Refrigerant piping R1 (first embodiment)]
FIG. 5 is a cross-sectional explanatory diagram of the refrigerant pipe R1 according to the first embodiment of the present disclosure. As shown in FIGS. 3 and 4, a thin copper tube 41 is connected to the outer peripheral surface of the pipe 23 via a copper joint 40 . The pipe 23, the joint 40, and the narrow pipe 41 constitute the refrigerant pipe R1 according to the first embodiment of the present disclosure. More specifically, the refrigerant pipe R1 includes a pipe 23 that is a first pipe made of stainless steel, a joint 40 that is a joint pipe provided on the outer peripheral surface of the pipe 23, and a pipe diameter smaller than that of the pipe 23. and a thin tube 41 which is a second pipe connected to the outer peripheral surface of the tube through a joint 40 . The material of the joint 40 is copper, which is different from the stainless steel that is the material of the pipe 23 . An outer peripheral surface 41 a of the thin tube 41 , which is a surface to be connected to the joint 40 , is made of the same material (copper) as the joint 40 . As described above, the copper joint 40 and the stainless steel pipe 23 can be connected by furnace brazing. On the other hand, the copper joint 40 and the copper tube 41 can be connected by manual brazing (hand brazing) such as torch brazing (burner brazing). In FIG. 5, reference numeral 26 indicates a brazing material used during furnace brazing, and reference numeral 27 indicates a brazing material used during hand brazing. In FIG. 5 and FIGS. 8, 9, 11 and 13 described later, the thickness of the brazing filler material in the tube radial direction is exaggerated in order to make the brazed portion easier to understand.

Since the narrow tube 41 has a smaller diameter than other refrigerant pipes, if it is made of stainless steel, it has the adverse effect of increasing the manufacturing cost in order to obtain a predetermined accuracy. Therefore, in the present embodiment, the fine tube 41 is made of copper, and only the copper joint 40 is connected to the pipe 23 by furnace brazing. If the thin tube 41 and the joint 40 are connected to the pipe 23 by furnace brazing, the strength of the thin tube 41 may decrease during annealing in the furnace. connected with the As a result, the thin tube 41 can be connected to the pipe 23 via the joint 40 by manual brazing without causing a decrease in the strength of the thin tube 41 .

The fine tube 41 can be used as a service port, and is used for attaching functional parts such as a pressure sensor and for charging refrigerant during maintenance and inspection of the air conditioner A. FIG. As shown in FIG. 6, the narrow tube 41 is flared on one end side (tip side). The joint 40 has a flared shape with an enlarged diameter at one end as shown in FIG. The joint 40 includes a flared first large-diameter portion 40a, a short tubular first small-diameter portion 40b having a smaller diameter than the first large-diameter portion 40a, the first large-diameter portion 40a, and the first small-diameter portion 40b. and a first inclined portion 40c connecting the . The first small diameter portion 40b is inserted into the hole 36 formed in the pipe 23. As shown in FIG. At that time, the first inclined portion 40c, which is connected to one end of the first small diameter portion 40b inserted into the hole 36 and whose diameter is expanded from the one end, is the first positioning mechanism that determines the position of the joint 40 with respect to the pipe 23. function as The position of the joint 40 with respect to the pipe 23 is determined when the outer peripheral surface of the first inclined portion 40 c contacts the periphery of the hole 36 . The position of the joint 40 with respect to the pipe 23 can be easily determined by the first inclined portion 40c. The joint 40 is provided on the pipe 23 in a direction perpendicular to the axial direction of the pipe 23 .

Then, the other end 41 a of the thin tube 41 shown in FIG. 6 (the flared end opposite to the one end) is inserted into the flared first large diameter portion 40 a of the joint 40 . At that time, the first inclined portion 40c connected to one end of the first large diameter portion 40a into which the thin tube 41 is inserted and having a reduced diameter from the one end is the second positioning portion that determines the position of the thin tube 41 with respect to the joint 40. function as a mechanism. The position of the thin tube 41 with respect to the joint 40 is determined when the other end 41a of the thin tube 41 contacts the inner peripheral surface of the first inclined portion 40c. The position of the thin tube 41 with respect to the joint 40 can be easily determined by the first inclined portion 40c. In the refrigerant pipe R1, the first inclined portion 40c of the joint 40 functions as a first positioning mechanism and also functions as a second positioning mechanism.

[Refrigerant piping R2 (second embodiment)]
FIG. 8 is a cross-sectional explanatory diagram of the refrigerant pipe R2 according to the second embodiment of the present disclosure. The refrigerant pipe R2 differs from the refrigerant pipe R1 according to the first embodiment of the present disclosure described above in that the second pipe connected to the stainless steel pipe 23 is a stainless steel pipe instead of the copper thin pipe 41. It is that the main body 50 and the copper pipe 51 which is the connection portion provided at the end of the pipe main body 50 are used. Therefore, in the refrigerant pipe R2, elements or parts common to the refrigerant pipe R1 are denoted by the same reference numerals as those of the refrigerant pipe R1, and description thereof is omitted for simplicity.

In the refrigerant pipe R2, the second pipe composed of the pipe main body 50 and the copper pipe 51 has a smaller pipe diameter than the pipe 23, which is the first pipe. The pipe main body 50 includes a second large-diameter portion 50a, a second small-diameter portion 50b having a smaller diameter than the second large-diameter portion 50a, and a second large-diameter portion 50a and a second small-diameter portion 50b. and an inclined portion 50c. The copper pipe 51 can be connected to the outer peripheral surface of the second small diameter portion 50b, which is the end portion of the pipe main body 50, by furnace brazing. The length of the copper tube 51 is longer than the length of the second small diameter portion 50b, and the end portion 51a on one axial side (lower side in FIG. 8) of the copper pipe 51 is axially longer than the one end 50b1 of the second small diameter portion 50b. It is provided so as to extend in one direction.

The outer peripheral surface 51b of the copper pipe 51, which is the surface to be connected to the joint 40, is made of the same material as the joint 40, and the copper pipe 51 and the joint 40 can be connected by hand brazing. At the time of connection, the second pipe composed of the furnace-brazed pipe body 50 and the copper pipe 50 is inserted into the flared first large-diameter portion 40 a of the joint 40 . More specifically, the second pipe is inserted into the first large diameter portion 40a from the end portion 51a of the copper pipe 51 on one side in the axial direction. At that time, the first inclined portion 40 c of the joint 40 functions as a second positioning mechanism that determines the position of the copper pipe 50 with respect to the joint 40 . The position of the copper pipe 50 with respect to the joint 40 is determined when the end portion 51a of the copper pipe 51 contacts the inner peripheral surface of the first inclined portion 40c. The position of the copper pipe 50 with respect to the joint 40 can be easily determined by the first inclined portion 40c. When the first small-diameter portion 40b of the joint 40 is inserted into the hole 36 formed in the pipe 23, the first inclined portion 40c determines the position of the joint 40 with respect to the pipe 23, similarly to the refrigerant pipe R1. It functions as a first positioning mechanism. The position of the joint 40 with respect to the pipe 23 can be easily determined by the first inclined portion 40c. In FIG. 8, reference numeral 28 indicates a brazing material used during furnace brazing, and reference numeral 29 indicates a brazing material used during hand brazing.

The pipe main body 50 can be used as a service port, and is used for attaching functional parts such as a pressure sensor and for charging refrigerant during maintenance and inspection of the air conditioner A. FIG.

[Refrigerant pipe R3 (third embodiment)]
FIG. 9 is a cross-sectional explanatory diagram of the refrigerant pipe R3 according to the third embodiment of the present disclosure, and FIG. 10 is an explanatory diagram of the joint of the refrigerant pipe R3 shown in FIG.
The refrigerant pipe R3 includes a pipe 60 that is a first pipe made of stainless steel, a joint 61 that is a joint pipe provided on the outer peripheral surface of the pipe 60, and a pipe diameter smaller than that of the pipe 60. and a second pipe connected via 61 . The second pipe of the refrigerant pipe R3 is composed of a pipe main body 62 made of stainless steel and a copper pipe 63 which is a connection portion provided at the end of the pipe main body 62 . In the refrigerant pipe R3, the second pipe composed of the pipe main body 62 and the copper pipe 63 has a smaller pipe diameter than the pipe 60, which is the first pipe. The material of the joint 61 is copper, which is different from the stainless steel that is the material of the pipe 60 . An outer peripheral surface 63a of the copper pipe 63, which is a surface to be connected to the joint 61, is made of the same material as the joint 61 (copper).

As shown in FIG. 10, the joint 61 has the shape of a short tube. An annular bead 64 is formed near the axial center of the outer peripheral surface 61 a of the joint 61 . The bead 64 functions as a first positioning mechanism for positioning the joint 61 with respect to the pipe 60 when the joint 61 is inserted into the hole 65 formed in the pipe 60, as shown in FIG. The position of the joint 61 with respect to the pipe 60 is determined by the contact of the bead 64 with the periphery of the hole 65 . The bead 64 makes it possible to easily determine the position of the joint 61 with respect to the pipe 60 . The joint 61 is provided on the pipe 60 in a direction perpendicular to the axial direction of the pipe 60 .

The pipe main body 62 includes a second large-diameter portion 62a, a second small-diameter portion 62b having a smaller diameter than the second large-diameter portion 62a, and a second large-diameter portion 62a and a second small-diameter portion 62b. and an inclined portion 62c. The copper pipe 63 can be connected to the outer peripheral surface of the second small diameter portion 62b, which is the end portion of the pipe main body 62, by furnace brazing. The length of the second small-diameter portion 62b is longer than the length of the copper tube 63, and the end 62b1 on one axial side (lower side in FIG. 9) of the second small-diameter portion 62b is longer than the one end 63b of the copper tube 63 in the axial direction. It is provided so as to extend to one side. The length of the copper pipe 63 may be longer than the length of the second small diameter portion 62b of the pipe main body 62 as long as the brazing margin between the joint 61 and the copper pipe 63 is ensured.

An annular bead 66 is formed near the center in the axial direction of the outer peripheral surface 63 a of the copper tube 63 . As shown in FIG. 9 , the bead 66 is formed by the second pipe with respect to the joint 61 when the second pipe composed of the pipe body 62 and the copper pipe 63 is inserted into the joint 61 provided in the pipe 60 . It functions as a second positioning mechanism that determines the position of the . The position of the second pipe with respect to the joint 61 is determined by the bead 66 coming into contact with the periphery of the opening of the joint 61 . The bead 66 makes it possible to easily determine the position of the second pipe with respect to the joint 61 .

In the refrigerant pipe R3, the material of the joint 61 is copper, which is different from the stainless steel that is the material of the pipe 60. As shown in FIG. Further, the outer peripheral surface 63 a of the copper pipe 63 constituting the second pipe, which is the surface to be connected with the joint 61 , is made of the same material (copper) as the joint 61 . The copper joint 61 and the stainless steel pipe 60 can be connected by furnace brazing. On the other hand, the copper joint 61 and the copper pipe 63 can be connected by hand brazing. In FIG. 9, reference numerals 43 and 44 denote brazing filler metals used during furnace brazing, and reference numeral 45 denotes brazing filler metals used during hand brazing.

The pipe main body 62 can be used as a service port, and is used to attach functional parts such as a pressure sensor and to charge refrigerant during maintenance and inspection of the air conditioner A.

In the refrigerant pipe R3, the second pipe is connected to the pipe 60 such that the end 62b1 of the pipe main body 62 of the second pipe is positioned inside the pipe 60. As shown in FIG. In other words, the entire end 62b1 of the pipe main body 62 of the second pipe is positioned closer to the flow path P through which the refrigerant of the pipe 60 flows than the outer peripheral surface of the pipe 60 (see FIG. 9). The pipe main body 62 and the copper pipe 63 of the second pipe overlap with the pipe 60 in the radial direction of the second pipe. At the connection portion H1 (see FIG. 9) where the joint 61 is connected to the pipe 60, the pipe main body 62 and the copper pipe 63 of the second pipe overlap with the pipe 60 in the radial direction of the second pipe. In this case, since the pipe main body 62 of the second pipe is connected to the pipe 60 via the joint 61, at the connection portion H1 between the joint 61 and the pipe 60, the pipe of the second pipe extends in the radial direction of the second pipe. There will be a body 62 and a copper tube 63 and a joint 61 . Moreover, the pipe main body 62 is made of stainless steel and has higher rigidity than a copper pipe. Due to the presence of the pipe main body 62 and the copper pipe 63, not only the strength of the connection portion H1 between the joint 61 and the pipe 60 but also the strength of the first pipe and the first pipe via the joint 61 is increased compared to the case where only the joint 61 is present. The strength of the connection between the two pipes can be improved. If a portion of the refrigerant pipe R3 includes a portion where copper is present alone, stress will concentrate on that portion and cause damage, but the refrigerant pipe R3 has a portion where copper is present alone. Therefore, damage due to stress concentration can be suppressed.

[Refrigerant pipe R4 (fourth embodiment)]
FIG. 11 is a cross-sectional explanatory diagram of the refrigerant pipe R4 according to the fourth embodiment of the present disclosure, and FIG. 12 is an explanatory diagram of the joint of the refrigerant pipe R4 shown in FIG.
The refrigerant pipe R4 includes a pipe 70 that is a first pipe made of stainless steel, a joint 71 that is a joint pipe provided on the outer peripheral surface of the pipe 70, a pipe diameter smaller than that of the pipe 70, and a joint on the outer peripheral surface of the pipe 70. and a second pipe connected via 71 . The second pipe of the refrigerant pipe R4 is composed of a pipe main body 72 made of stainless steel and a copper pipe 73 which is a connecting portion provided at the end of the pipe main body 72 . In the refrigerant pipe R4, the second pipe composed of the pipe main body 72 and the copper pipe 73 has a smaller pipe diameter than the pipe 70, which is the first pipe. The material of the joint 71 is copper, which is different from the stainless steel that is the material of the pipe 70 . An outer peripheral surface 73 a of the copper pipe 73 , which is a surface to be connected to the joint 71 , is made of the same material (copper) as the joint 71 .

As shown in FIG. 12, the joint 71 has the shape of a short tube. The joint 71 includes a first large-diameter portion 71a, a first small-diameter portion 71b having a smaller diameter than the first large-diameter portion 71a, and a first slope connecting the first large-diameter portion 71a and the first small-diameter portion 71b. and a portion 71c. An enlarged diameter portion 74 is formed by flaring at one axial end of the first large diameter portion 71a. The enlarged diameter portion 74 functions as a first positioning mechanism for positioning the joint 71 with respect to the pipe 70 when the joint 71 is inserted into the hole 75 formed in the pipe 70, as shown in FIG. The position of the joint 71 with respect to the pipe 70 is determined when the outer peripheral surface of the enlarged diameter portion 74 contacts the periphery of the hole 75 . The enlarged diameter portion 74 makes it possible to easily determine the position of the joint 71 with respect to the pipe 70 . The joint 71 is provided on the pipe 70 in a direction perpendicular to the axial direction of the pipe 70 .

The pipe main body 72 includes a second large diameter portion 72a, a second small diameter portion 72b having a smaller diameter than the second large diameter portion 72a, and a second large diameter portion 72a and a second small diameter portion 72b connecting the second large diameter portion 72a and the second small diameter portion 72b. and an inclined portion 72c. The copper pipe 73 can be connected to the outer peripheral surface of the second small diameter portion 72b, which is the end portion of the pipe main body 72, by furnace brazing. The length of the copper tube 73 is longer than the length of the second small diameter portion 72b, and the end 73b on one axial side (lower side in FIG. 11) of the copper tube 73 is axially longer than the one end 72b1 of the second small diameter portion 72b. It is provided so as to extend to one side.

In the refrigerant pipe R4, the material of the joint 71 is copper, which is different from the stainless steel that is the material of the pipe 70 . Further, the outer peripheral surface 73 a of the copper pipe 73 constituting the second pipe, which is the surface to be connected with the joint 71 , is made of the same material (copper) as the joint 71 . The copper joint 71 and the stainless steel pipe 70 can be connected by furnace brazing. On the other hand, the copper joint 71 and the copper pipe 73 can be connected by hand brazing. In order to connect the joint 71 and the copper pipe 73 , a second pipe consisting of a furnace brazed pipe body 72 and the copper pipe 73 is inserted into the joint 71 . At that time, the inclined portion 71 c of the joint 71 functions as a second positioning mechanism that determines the position of the copper pipe 73 with respect to the joint 71 . The position of the copper pipe 73 with respect to the joint 71 is determined by the end 73b of the copper pipe 73 coming into contact with the inner peripheral surface of the inclined portion 71c. The position of the second pipe with respect to the joint 71 can be easily determined by the inclined portion 71c. In FIG. 11, reference numerals 46 and 47 denote brazing filler metals used during furnace brazing, and reference numeral 48 denotes brazing filler metals used during hand brazing.

The pipe main body 72 can be used as a service port, and is used for attaching functional parts such as a pressure sensor and for charging refrigerant during maintenance and inspection of the air conditioner A.

In the refrigerant pipe R4, the second pipe is connected to the pipe 70 such that the end 72b1 of the pipe main body 72 of the second pipe is positioned inside the pipe 70. As shown in FIG. In other words, the entire end 72b1 of the pipe main body 72 of the second pipe is positioned closer to the flow path P through which the refrigerant of the pipe 70 flows than the outer peripheral surface of the pipe 70 (see FIG. 11). The pipe main body 72 and the copper pipe 73 of the second pipe overlap with the pipe 70 in the radial direction of the second pipe. At the connection portion H2 (see FIG. 11) where the joint 71 is provided on the pipe 70, the pipe main body 72 and the copper pipe 73 of the second pipe overlap with the pipe 70 in the radial direction of the second pipe. In this case, since the pipe main body 72 of the second pipe is connected to the pipe 70 via the joint 71, at the joint H2 between the joint 71 and the pipe 70, the pipe of the second pipe extends in the radial direction of the second pipe. There will be a body 72 and a copper tube 73 and a joint 71 . Moreover, the pipe main body 72 is made of stainless steel and has higher rigidity than a copper pipe. Due to the presence of the pipe main body 72 and the copper pipe 73, not only the strength of the connection portion H2 between the joint 71 and the pipe 70 but also the strength of the first pipe and the first pipe via the joint 71 is increased compared to the case where only the joint 71 is present. The strength of the connection between the two pipes can be improved. If a portion of the refrigerant pipe R4 includes a portion where copper is present alone, stress will concentrate on that portion and cause damage, but the refrigerant pipe R4 has a portion where copper is present alone. Therefore, damage due to stress concentration can be suppressed.

[Action and effect of the embodiment]
In each embodiment described above, the material of the joints 40, 61, 71 provided on the outer peripheral surfaces of the pipes 23, 60, 70 made of stainless steel is copper, which is a material different from stainless steel. In addition, a thin pipe 41 (refrigerant pipe R1), a pipe main body 50 and a copper pipe 51 (refrigerant pipe R2), which are connected to the outer peripheral surfaces of the pipes 23, 60, 70 via the joints 40, 61, 71, the pipe main body 62 and The surfaces to be connected to the joints 40, 61, 71 of the copper pipe 63 (refrigerant pipe R3), or the pipe body 72 and the copper pipe 73 (refrigerant pipe R4) are made of the same material as the joints 40, 61, 71. is copper. Therefore, it is possible to easily connect the second pipe, which is a thin pipe, to the first pipe made of stainless steel without brazing the stainless steel pipe, which involves complicated work.

More specifically, when brazing stainless steel pipes, a passivation film (oxide film) is formed on the stainless steel surface. Requires flux to remove. In the refrigeration system, the refrigerant flows through the refrigerant circuit 3, which is a closed circuit. Therefore, if flux remains in the refrigerant piping, the flux will be mixed with the refrigerant, and the refrigerant itself and the compressor 4 into which the refrigerant flows will be damaged. It may adversely affect the performance of component parts. For this reason, it is essential to remove the flux after brazing.

In each of the above-described embodiments, the stainless pipes 23, 60, 70 and the joints 40, 61, 71 can be connected by furnace brazing. This in-furnace brazing is a method of performing brazing in a predetermined gas atmosphere such as a hydrogen gas atmosphere capable of removing an oxide film inside a continuous furnace or the like. Therefore, stainless steel can be brazed without using flux, and as a result, there is no need to remove the flux after brazing. Then, the joints 40, 61, 71, the thin pipe 41 (refrigerant pipe R1) which is the second pipe, the pipe main body 50 and the copper pipe 51 (refrigerant pipe R2), the pipe main body 62 and the copper pipe 63 (refrigerant pipe R3), or , the connection between the pipe body 72 and the copper pipe 73 (refrigerant pipe R4) is a copper-to-copper connection. can be connected to pipes 23, 60, 70 manufactured by

Further, in each of the above-described embodiments, the joints 40, 61, and 71 are made of copper, and the thin tube 41 (refrigerant pipe R1), the pipe main body 50 and the copper pipe 51 (refrigerant pipe R2), the pipe main body 62 and the copper pipe The surfaces to be connected to the joints 40, 61, 71 of the pipe 63 (refrigerant pipe R3), or the pipe body 72 and the copper pipe 73 (refrigerant pipe R4) are also made of copper. Therefore, the joints 40, 61, 71 and the thin tube 41 and the copper tubes 51, 63, 73 can be connected by hand brazing, and the thin tube 41 and the copper tubes 51, 63, 73 can be easily made of stainless steel. of pipes 23, 60, 70.

Further, in the above-described embodiments (second to fourth embodiments), the second pipes connected to the stainless steel pipes 23, 60, 70 are the stainless steel pipe bodies 50, 62, 72 and the pipe bodies 50 , 62 and 72, which are connecting portions, and these copper pipes 51, 63 and 73 are connected to the joints 40, 61 and 71. It includes outer peripheral surfaces 51b, 63a, 73a which are surfaces. A second pipe is connected to the outer peripheral surface of the pipes 23, 60, 70 via joints 40, 61, 71 made of a material different from stainless steel, and copper provided in the pipe main bodies 50, 62, 72 of the second pipe The surfaces to be connected of the pipes 51, 63, 73 are made of the same material (copper) as the joints 40, 61, 71. Therefore, the stainless steel pipes need not be brazed, which involves complicated work, and the copper pipes 51, 63, 73 can be easily connected to the stainless steel pipes 23, 60, 70.

Further, in the above-described embodiments (second to fourth embodiments), the pipe main bodies 50, 62, 72 have a diameter larger than the second large diameter portions 50a, 62a, 72a and the second large diameter portions 50a, 62a, 72a. It has a small second small diameter portion 50b, 62b, 72b. Copper pipes 51, 63, 73 are connected as connection portions to the outer peripheral surfaces of the second small diameter portions 50b, 62b, 72b. Further, the outer peripheral surfaces 51b, 63a, 73a of the copper pipes 51, 63, 73 constitute the surfaces to be connected to the joints 40, 61, 71, respectively. The surfaces to be connected and the joints 40, 61, 71 are made of the same material (copper), and can be easily connected by a conventional method such as manual brazing. In addition, since the pipe bodies 50, 62, 72 are made of stainless steel, the rigidity can be improved and the cost can be reduced as compared with copper pipes.

Further, in the above-described embodiment (first embodiment), the second pipe connected to the pipe 23 via the joint 40 is the thin copper pipe 41 . Connection between the thin tube 41 made of copper and the joint 40 made of copper can be easily performed by a conventional method such as manual brazing.

Further, in each of the above-described embodiments, the inclined portion 40c, the bead 64, and the enlarged diameter portion 74, which are the first positioning mechanisms for determining the positions of the joints 40, 61, and 71 with respect to the pipes 23, 60, and 70, are the joints 40, 61, 71, the positions of the joints 40, 61, 71 relative to the pipes 23, 60, 70 can be determined easily.

In addition, in the above-described embodiments (first, second, and fourth embodiments), the joints 40 and 71 have inclined portions 40c and 71c, which are second positioning mechanisms for determining the position of the second pipe with respect to the joints 40 and 71. are doing. Further, in the above-described embodiment (third embodiment), the copper pipe 63 has the bead 66 which is the second positioning function for determining the position of the copper pipe 63 with respect to the joint 71 . Thereby, the position of the second pipe with respect to the joints 40, 61, 71 can be easily determined.

Further, in the above-described embodiments (third and fourth embodiments), the pipe bodies 62 and 72 and the copper pipes 63 and 73 that constitute the second pipe overlap the pipes 60 and 70 in the radial direction of the second pipe. ing. More specifically, in the connection portions H1 and H2 where the joints 61 and 71 are provided on the pipes 60 and 70, the pipe bodies 62 and 72 and the copper pipes 63 and 73 of the second pipe are arranged in the radial direction of the second pipe. It overlaps with the pipes 60 and 70 . Since the pipe bodies 62, 72 and the copper pipes 63, 73 are connected to the pipes 60, 70 via the joints 61, 71, the joints H1, H2 between the joints 61, 71 and the pipes 60, 70 have the second pipes , pipe bodies 62, 72, copper pipes 63, 73, and joints 61, 71 of the second pipe exist in the pipe radial direction. Also, the pipe bodies 62 and 72 are made of stainless steel and have higher rigidity than copper pipes. Due to the presence of the pipe bodies 62, 72 and the copper pipes 63, 73, not only the strength of the connecting portions H1, H2 between the joints 61, 71 and the pipes 60, 70 but also , the strength of the connection between the first pipe and the second pipe via the joints 61 and 71 can be improved. If a portion of the refrigerant pipes R3 and R4 includes a portion where copper is present alone, stress will concentrate on that portion and cause damage. Since it does not have a portion existing in , it is possible to suppress damage due to stress concentration.

Further, the air conditioners A and B according to the above-described embodiments are provided with a refrigerant circuit 3 including a plurality of element parts and refrigerant pipes 8 connecting the plurality of element parts. Refrigerant pipes 8 to be connected include the refrigerant pipes according to the first to fourth embodiments described above. In the refrigerant pipes according to the first to fourth embodiments, the material of the joints 40, 61, 71 provided on the outer peripheral surfaces of the pipes 23, 60, 70 made of stainless steel is copper, which is different from stainless steel. In addition, a thin pipe 41 (refrigerant pipe R1), a pipe main body 50 and a copper pipe 51 (refrigerant pipe R2), which are connected to the outer peripheral surfaces of the pipes 23, 60, 70 via the joints 40, 61, 71, the pipe main body 62 and The surfaces to be connected to the joints 40, 61, 71 of the copper pipe 63 (refrigerant pipe R3), or the pipe body 72 and the copper pipe 73 (refrigerant pipe R4) are made of the same material as the joints 40, 61, 71. is copper. Therefore, it is possible to easily connect the second pipe, which is a thin pipe, to the first pipe made of stainless steel without brazing the stainless steel pipe, which involves complicated work.

[Other Modifications]
The present disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims.
For example, in the above-described embodiment, a copper joint, which is a material different from stainless steel, is used as the joint provided on the outer peripheral surface of the stainless steel first pipe. Or an aluminum alloy can also be used. When a copper alloy joint is used, the surface of the second pipe to be connected to the joint is made of a copper alloy or copper, which is the same material as the copper alloy. When using an aluminum joint, the surface of the second pipe to be connected to the joint is made of aluminum or an aluminum alloy, which is the same material as aluminum. When using a joint made of an aluminum alloy, the surface of the second pipe to be connected to the joint is made of aluminum alloy or aluminum, which is the same material as the aluminum alloy. As the copper alloy, for example, one containing 98% by weight or more of copper is used. More preferably, a copper alloy containing 99% by weight or more of copper is used. As the aluminum alloy, for example, one containing 95% by weight or more of aluminum is used.

In the above-described embodiment, when a pipe body made of stainless steel is used, the pipe body has a shape with a reduced diameter and includes a second large diameter portion and a second small diameter portion. Not limited. For example, the second pipe may be a pipe made of stainless steel which is not reduced in diameter and has a constant diameter and which is covered with a copper pipe.

In addition, in the above-described embodiments (third and fourth embodiments), the second pipe is composed of the pipe main body made of stainless steel and the copper pipe. can be the second pipe. In this case, the thin copper pipe, which is the second pipe, is connected to the outer peripheral surface of the pipe (first pipe) 60 via the joint 61, or is connected to the outer circumference of the pipe (first pipe) 70 via the joint 71. connected to the face.

Further, in the above-described embodiment, the outer peripheral surface of the copper tube functions as the surface to be connected, but as the surface to be connected, a copper plating layer can be used as shown in FIG. 13 . FIG. 13 is a cross-sectional explanatory view of a modification of the refrigerant pipe R4 shown in FIG. In this modified example, elements or parts common to the refrigerant pipe R4 are denoted by the same reference numerals as those of the refrigerant pipe R4, and descriptions thereof are omitted for the sake of simplicity.

In the modification shown in FIG. 13, a copper plated layer 90 is used instead of the copper tube 73 . The stainless pipe main body 91, which is the second pipe, on which the copper plating layer 90 is formed, and the copper joint 92 can be connected by hand brazing. The pipe main body 91, like the pipe main body 72 of the refrigerant pipe R4, has a second large diameter portion 91a, a second small diameter portion 91b smaller in diameter than the second large diameter portion 91a, and a second large diameter portion 91a. It has a second inclined portion 91c connected to the second small diameter portion 91b. The copper plating layer 90 is formed on the outer peripheral surface of the second small diameter portion 91b of the pipe main body 91 . In addition, the pipe main body does not have to have a small diameter portion. That is, a thin tube having a constant diameter can be used as the pipe main body, and in this case, a copper plating layer is formed on the outer peripheral surface of the thin tube.

A joint 92 provided in the pipe 70 has a short pipe shape like the joint 71 of the refrigerant pipe R4. The joint 92 includes a first large-diameter portion 92a, a first small-diameter portion 92b having a smaller diameter than the first large-diameter portion 92a, and an inclined portion 92c connecting the first large-diameter portion 92a and the first small-diameter portion 92b. and An enlarged diameter portion 93 is formed by flaring at one axial end of the first large diameter portion 92a. In FIG. 13, reference numeral 94 indicates a brazing material used during furnace brazing, and reference numeral 95 indicates a brazing material used during hand brazing.
The copper plating layer formed on the outer peripheral surface of the second pipe can also be used as the connection surface of the refrigerant pipe R2 and the refrigerant pipe R3. Also in this case, the copper plating layer of the second pipe can be connected to the copper joint 40 (refrigerant pipe R2) or the copper joint 61 (refrigerant pipe R3) by manual brazing.

In the above-described embodiment (third embodiment), the annular rib 64 is formed on the outer peripheral surface of the joint 61 as the first positioning mechanism. can also be set to For example, three ribs can be provided at 120° intervals along the circumferential direction, and four ribs can be provided at 90° intervals along the circumferential direction. Similarly, in the above-described embodiment (third embodiment), the annular rib 66 is formed on the outer peripheral surface of the copper pipe 63 as the second positioning mechanism, but the rib is formed along the outer peripheral surface in the circumferential direction. It can also be provided discontinuously. For example, three ribs can be provided at 120° intervals along the circumferential direction, and four ribs can be provided at 90° intervals along the circumferential direction.

In addition, in the above-described embodiment (fourth embodiment), the inclined portion 71c of the joint 71 is used as the second positioning mechanism that determines the position of the second pipe with respect to the joint 71, but other configurations can also be used. . For example, a short tube-shaped joint 80 as shown in FIG. 14 may be employed as the joint, and an annular rib 81 provided on the inner peripheral surface of this joint 80 may be used as the second positioning mechanism. When the second pipe 82 is inserted into the joint 80, the tip 82a of the second pipe 82 abuts against the rib 81 and its axial movement is restricted. This makes it possible to easily determine the position of the second pipe 82 with respect to the joint 80 . At one end of the joint 80 in the axial direction, an enlarged diameter portion 83 that functions as a first positioning mechanism that determines the position of the joint 80 with respect to the first pipe (not shown) is formed by flaring. As for the rib 81 , a plurality of ribs can be discontinuously provided along the circumferential direction on the inner peripheral surface of the joint 80 in the same manner as the rib 64 or the rib 66 described above.

In the above-described embodiment, the stainless steel pipe 23 is connected to the copper thin pipe 41 via the copper joint 40, and this thin pipe 41 is used as a service port. It is also possible to connect a thin tube made of a different material through a joint made of a material different from the above, and connect the high pressure sensor to this thin tube. Alternatively, a thin tube made of a material different from stainless steel may be connected to the pipe 22 made of stainless steel via a joint made of a material different from stainless steel, and the low-pressure sensor may be connected to this thin tube. Alternatively, a thin tube made of a material different from stainless steel may be connected to the stainless steel pipe 24 via a joint made of a material different from stainless steel, and this thin tube may be used as a refrigerant charge port.

Further, in the above-described embodiment, the separate type or separate type air conditioner in which the indoor unit and the outdoor unit are separate units was exemplified, but the air conditioner that is the refrigerating device of the present disclosure is not limited to this. The refrigerating apparatus of the present disclosure also includes an air conditioner of a type in which element parts of the air conditioner such as a compressor, a condenser, an evaporator, and a fan are housed in an integral casing.
Further, in the above-described embodiment, the accumulator is provided on the suction side of the compressor, but the air conditioner may be provided without such an accumulator.

1: Indoor unit 2: Outdoor unit 2a: Casing 3: Refrigerant circuit 4: Compressor 4a: Suction part 4b: Discharge part 5: Indoor heat exchanger 6: Electronic expansion valve 7: Outdoor heat exchanger 8: Refrigerant piping 9: Indoor fan 10: Outdoor fan 11: Accumulator 12: Oil separator 13: Valve 14: Oil return pipe 15: Muffler 16: Four-way switching valve 17: Gas shutoff valve 18: Liquid shutoff valve 21: Piping 22: Piping 23: Piping 24: Piping 31: First port 32: Second port 33: Third port 34: Fourth port 36: Hole 40: Joint 40a: First large diameter portion 40b: First small diameter portion 40c: First inclined portion 41: Thin tube 50: Pipe main body 50a: Second large diameter portion 50b: Second small diameter portion 50c: Second inclined portion 51: Copper pipe 60: Pipe 61: Joint 62: Pipe main body 62a: Second large diameter portion 62b: Second small diameter Portion 62c: Second inclined portion 63: Copper pipe 64: Bead 65: Hole 66: Bead 70: Pipe 71: Joint 71a: First large diameter portion 71b: First small diameter portion 71c: First inclined portion 72: Pipe body 72a : Second large diameter portion 72b: Second small diameter portion 72c: Second inclined portion 73: Copper pipe 74: Expanded diameter portion 75: Hole 80: Joint 81: Rib 82: Second pipe 83: Expanded diameter portion 90: Copper plating Layer A: Air conditioner (refrigerating equipment)
B: Air conditioner (freezer)
C: Switching Mechanism P: (Refrigerant) Flow Path R1: Refrigerant Piping (First Embodiment)
R2: Refrigerant piping (second embodiment)
R3: Refrigerant piping (third embodiment)
R4: Refrigerant piping (fourth embodiment)

Claims (11)

A stainless steel first pipe (23, 60, 70) through which a refrigerant flows;
a joint pipe (40, 61, 71) provided on the outer peripheral surface of the first pipe (23, 60, 70) and made of a material different from stainless steel;
A second pipe having a pipe diameter smaller than that of the first pipe (23, 60, 70) and connected to the outer peripheral surface of the first pipe (23, 60, 70) via the joint pipe (40, 61, 71). 2 pipes (41, 50, 51, 62, 63, 72, 73), and the joint pipes (40, 61, 71) of the second pipes (41, 50, 51, 62, 63, 72, 73) ) are made of the same material as the joint pipes (40, 61, 71) of the refrigerant pipes (R1, R2, R3, R4) of the refrigeration equipment (A, B). . The joint pipe (40, 61, 71) is provided in the first pipe (23, 60, 70) in a direction orthogonal to the axial direction of the first pipe (23, 60, 70). Refrigerant pipes (R1, R2, R3, R4) of the refrigeration system (A, B) according to 1. The connecting surfaces (51b, 63a, 73a) of the joint pipes (40, 61, 71) and the second pipes (41, 50, 51, 62, 63, 72, 73) are made of copper or a copper alloy. Refrigerant pipes (R1, R2, R3, R4) of the refrigeration system (A, B) according to claim 1 or claim 2. The second pipes (41, 50, 51, 62, 63, 72, 73) are provided at pipe bodies (50, 62, 72) made of stainless steel and ends of the pipe bodies (50, 62, 72). and a connecting portion (51, 63, 73), wherein the connecting portion (51, 63, 73) includes the connected surface (51b, 63a, 73a). Refrigerant piping (R1, R2, R3, R4) of the refrigerating device (A, B) according to the above paragraph. The pipe body (50, 62, 72) has a second large diameter portion (50a, 62a, 72a) and a second small diameter portion (50b, 62b) smaller in diameter than the second large diameter portion (50a, 62a, 72a). , 72b), and the connection portion (51, 63, 73) is a pipe (51, 63, 73) provided on the outer peripheral surface of the second small diameter portion (51b, 63b, 73b). 5. Refrigerant pipes (R1, R2, R3, R4) of the refrigeration system (A, B) according to 4. A refrigerant pipe (R1) of a refrigeration system (A, B) according to any one of claims 1 to 3, wherein said second pipe is a copper pipe (41). A first positioning mechanism (40c, 64, 74) for determining the position of the joint pipe (40, 61, 71) with respect to the first pipe (23, 60, 70) is provided on the outer periphery of the joint pipe (40, 61, 71). Refrigerant pipes (R1, R2, R3, R4) of a refrigeration system (A, B) according to any one of claims 1 to 6, provided on the surface. The joint pipe (40, 61, 71) or the second pipe (41, 50, 51, 62, 63, 72, 73) is the second pipe (41, 50) for the joint pipe (40, 61, 71). , 51, 62, 63, 72, 73) having a second positioning mechanism (40c, 66, 71c) for positioning the Refrigerant piping (R1, R2, R3, R4). Claims 1 to 8, wherein the second pipe (62, 63, 72, 73) overlaps the first pipe (60, 70) in the radial direction of the second pipe (62, 63, 72, 73). Refrigerant pipes (R3, R4) of the refrigeration system (A, B) according to any one of the above. The pipe main body (62, 72) of the second pipe (62, 63, 72, 73) is positioned so as to extend from the first pipe (60, 70) in the radial direction of the second pipe (62, 63, 72, 73) Refrigerant pipes (R3, R4) of a refrigeration system (A, B) according to claim 4 or claim 5, overlapping with. A refrigerant circuit (3) comprising a plurality of element parts and a refrigerant pipe (8) connecting the plurality of element parts,
A refrigeration system (A , B).

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