JP2021025757A - Refrigerant pipe and refrigerating device - Google Patents

Abstract

To facilitate connection between refrigerant pipes made of stainless steel.SOLUTION: A refrigerant pipe constitutes a refrigerant circuit 4 of a refrigerating device 1, and comprises a first pipe 21 and a second pipe 22. The first pipe 21 comprises: a first pipe body 21a made of stainless steel; and a first connecting part 21b provided at an end part in a pipe axis direction of the first pipe body 21a, and made of a material different from the stainless steel. The second pipe 22 comprises: a second pipe body 22a made of the stainless steel; and a second connecting pipe 22b provided at an end part in the pipe axis direction of the second pipe body 22a, and made of the same material as that of the first connecting pipe 21b. The first connecting pipe 21b and the second connecting pipe 22b are connected.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to refrigerant piping and refrigeration equipment.

In heat pump type refrigeration equipment such as air conditioners, element parts such as compressors, oil separators, four-way switching valves, heat source side heat exchangers, expansion mechanisms, user side heat exchangers, accumulators, and closing valves are connected by refrigerant piping. It is equipped with a connected refrigerant circuit. Further, in general, a copper pipe that can be easily processed such as bending is used for the refrigerant pipe. However, since the material cost of copper pipes is high, it is considered to use relatively inexpensive stainless steel as a material for refrigerant pipes (see, for example, Patent Document 1).

JP-A-2010-151327A

When stainless steel is used as the material of the refrigerant pipes, the work of manually brazing the stainless steel refrigerant pipes to each other may occur at the time of manufacturing the refrigerating apparatus or during maintenance such as parts replacement. However, brazing of a stainless steel refrigerant pipe requires work such as removing an oxide film on the surface, which complicates the work.

An object of the present disclosure is to facilitate connection between stainless steel refrigerant pipes.

(1) The refrigerant piping of the present disclosure is
Refrigerant piping that constitutes the refrigerant circuit of the refrigeration system.
Equipped with a first pipe and a second pipe,
The first pipe has a first pipe body made of stainless steel and a first connection part provided at an end portion of the first pipe body in the pipe axial direction and made of a material different from stainless steel.
The second pipe has a second pipe body made of stainless steel and a second connection part provided at an end portion of the second pipe body in the pipe axial direction and made of the same material as the first connection part.
The first connection portion and the second connection portion are connected.

According to this configuration, since the first pipe and the second pipe have the first connection part and the second connection part made of the same material, which are different from stainless steel, the first connection part and the second connection part are respectively. By connecting the pipes by brazing or the like, the brazing of stainless steel becomes unnecessary, and the first pipe and the second pipe can be easily connected.

(2) The refrigerant piping of the present disclosure is
Refrigerant piping that constitutes the refrigerant circuit of the refrigeration system.
Equipped with a first pipe and a second pipe,
The first pipe has a first pipe body made of stainless steel and a first connection part provided at an end portion of the first pipe body in the pipe axial direction and made of a material different from stainless steel.
The second pipe is provided with a second pipe body made of stainless steel and a second connection part made of the same material as the first connection part, which is provided at the end portion of the second pipe body in the pipe axis direction. Have,
The first connection portion and the second connection portion are connected.

According to this configuration, since the first pipe and the second pipe each have a first connection portion and a second connection portion made of the same material as the main component, which is different from stainless steel, the first connection portion and the second connection portion are formed. By connecting the second connection portion by brazing or the like, brazing of stainless steel becomes unnecessary, and the first pipe and the second pipe can be easily connected.

(3) Preferably, the first connecting portion and the second connecting portion are made of different materials having the same main component.
As described above, even when the first connection portion and the second connection portion are made of different materials having the same main component, the first pipe and the second pipe can be easily connected.

(4) Preferably, each of the first connecting portion and the second connecting portion is made of copper, a copper alloy, aluminum, or an aluminum alloy.
According to this configuration, the first connection portion and the second connection portion can be easily connected by brazing using an inexpensive brazing material.

(5) Preferably, the end portion of the first pipe body and the end portion of the second pipe body are arranged so as to overlap in the pipe radial direction.
According to this configuration, the first pipe main body made of stainless steel and the second pipe main body overlap in the pipe radial direction, so that the first pipe main body or the second pipe main body made of stainless steel overlaps in the pipe axial direction. Since it exists continuously, the strength of the refrigerant pipe can be increased.

(6) Preferably, the first connection portion is a plating layer applied to the end portion of the first pipe body, or a pipe attached to the end portion of the first pipe body.

(7) Preferably, the second connection portion is a plating layer applied to the end portion of the second pipe body, or a pipe attached to the end portion of the second pipe body.

(8) Preferably, one connection portion of the first connection portion and the second connection portion is a pipe, and the other connection portion is a plating layer.
The one connection portion and the one piping body provided with the one connection portion are connected by a first brazing material.
The one connecting portion and the other connecting portion are connected by a second brazing material.
The first brazing material has a higher melting point than the second brazing material.

According to this configuration, when the connection between the first pipe and the second pipe is disconnected for parts replacement or the like, the temperature at which the connection portion between the two pipes is higher than the melting point of the second brazing material and lower than the melting point of the first brazing material is lower. By heating with, only the second brazing material can be melted, and the connection between one pipe body and the pipe which is one connection portion can be maintained. Therefore, one connection can be reused for a new connection to the other connection.

(9) Preferably, the end portion of the first piping body or the second piping body is provided with a large diameter portion having a diameter larger than that of other portions of the piping body.
The first connection portion or the second connection portion is provided on the inner peripheral surface of the large diameter portion.

(10) Preferably, the end portion of the first piping main body or the second piping main body is provided with a small diameter portion having a diameter smaller than that of other parts of the piping main body.
The first connection portion or the second connection portion is provided on the outer peripheral surface of the small diameter portion.

(11) Preferably, one of the first pipe and the second pipe constitutes a joint for connecting the other pipe and the other stainless steel pipe.
With such a configuration, one of the pipes can be miniaturized, and the work of providing a connection portion on the pipe main body can be easily performed.

(12) Preferably, at least one of the first pipe and the second pipe is provided in the element component constituting the refrigerant circuit.

(13) Preferably, a joint pipe made of the same material as the first connecting portion and the second connecting portion is attached to at least one outer peripheral surface of the first piping main body and the second piping main body. Then, another pipe made of the same material as the joint pipe is connected to the joint pipe.
According to this configuration, functional parts such as sensors can be easily connected to the stainless steel pipe body via other pipes made of a material different from stainless steel.

(14) The refrigerating device includes a switching mechanism for switching the flow path of the refrigerant in the refrigerant circuit.
The first piping body or the second piping body is connected to the switching mechanism.

(15) The refrigerating device of the present disclosure is
The refrigerant pipe according to any one of (1) to (14) above, and
It constitutes a refrigerant circuit and includes element parts to which the refrigerant pipe is connected.

It is a schematic block diagram of the refrigerating apparatus provided with the refrigerant pipe which concerns on 1st Embodiment. It is sectional drawing which shows the connection part of the 1st pipe and the 2nd pipe of a refrigerant pipe. It is an enlarged sectional view of the part A of FIG. It is sectional drawing which shows the connection part of the 1st pipe and the 2nd pipe of the refrigerant pipe which concerns on 2nd Embodiment. It is sectional drawing which shows the state before brazing of the 1st pipe main body and 1st connection pipe of 1st pipe. It is sectional drawing which shows the modification of the 1st pipe main body. It is sectional drawing which shows the further modification of the 1st pipe body. It is sectional drawing which shows the further modification of the 1st pipe body. It is sectional drawing which shows the further modification of the 1st pipe body. It is sectional drawing which shows the connection part of the 1st pipe and the 2nd pipe of the refrigerant pipe which concerns on 3rd Embodiment. It is sectional drawing which shows the connection part of the 1st pipe and the 2nd pipe of the refrigerant pipe which concerns on 4th Embodiment. FIG. 5 is an enlarged cross-sectional view showing a connection portion between the first pipe and the second pipe of the refrigerant pipe according to the fifth embodiment. It is sectional drawing which shows the connection part of the 1st pipe and the 2nd pipe of the refrigerant pipe which concerns on 6th Embodiment. It is sectional drawing which shows the connection part of the 1st pipe and the 2nd pipe of the refrigerant pipe which concerns on 7th Embodiment. It is sectional drawing which shows the connection part of the 1st pipe and the 2nd pipe of the refrigerant pipe which concerns on 8th Embodiment. It is sectional drawing which shows the connection part of the 1st pipe and the 2nd pipe of the refrigerant pipe which concerns on 9th Embodiment. It is a front view which shows the valve unit which integrated the four-way switching valve and a refrigerant pipe. It is a perspective view which shows the state which the valve unit was connected to the element component. It is a perspective view which shows the state which connected the valve unit which concerns on a comparative example to an element component.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.
[First Embodiment]
(Overall configuration of refrigeration equipment)
Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a refrigerating device provided with a refrigerant pipe according to the first embodiment.
The refrigerating device 1 is, for example, an air conditioner that adjusts the temperature and humidity in the room, and includes an outdoor unit 2 installed outdoors and an indoor unit 3 installed indoors. The outdoor unit 2 and the indoor unit 3 are connected to each other by a refrigerant pipe 10.

The refrigeration apparatus 1 includes a refrigerant circuit 4 that performs a vapor compression refrigeration cycle. The refrigerant circuit 4 includes a plurality of element parts and a refrigerant pipe 10 for connecting the plurality of element parts. The refrigerant circuit 4 has, as element parts, an indoor heat exchanger 11, a compressor 12, a muffler 13, an outdoor heat exchanger 14, an expansion mechanism 15, an accumulator 16, a four-way switching valve (switching mechanism) 17, and a closing valve 18L, 18G. Etc., and these are connected by a refrigerant pipe 10. The refrigerant pipe 10 includes a liquid pipe 10L and a gas pipe 10G. The liquid pipe 10L and the gas pipe 10G are provided with closing valves 18L and 18G, respectively.

The indoor heat exchanger 11 is provided in the indoor unit 3 and exchanges heat between the refrigerant and the indoor air. As the indoor heat exchanger 11, for example, a cross-fin type fin-and-tube heat exchanger, a microchannel heat exchanger, or the like can be adopted. In the vicinity of the indoor heat exchanger 11, an indoor fan (not shown) for blowing indoor air to the indoor heat exchanger 11 and sending conditioned air into the room is provided.

The compressor 12, the muffler 13, the outdoor heat exchanger 14, the expansion mechanism 15, the accumulator 16, the four-way switching valve 17, and the closing valves 18L and 17G are provided in the outdoor unit 2. The compressor 12 compresses the refrigerant sucked from the suction pipe and discharges it from the discharge pipe. As the compressor 12, for example, various compressors such as a scroll compressor can be adopted.

The muffler 13 suppresses the pressure pulsation of the refrigerant discharged from the compressor 12. An oil separator may be provided between the discharge pipe of the compressor 12 and the four-way switching valve 17 in place of or in addition to the muffler 13. The oil separator separates the lubricating oil from the mixed fluid of the lubricating oil and the refrigerant discharged from the compressor 12.

The outdoor heat exchanger 14 exchanges heat between the refrigerant and the outdoor air. As the outdoor heat exchanger 14, for example, a cross-fin type fin-and-tube heat exchanger, a microchannel heat exchanger, or the like can be adopted. An outdoor fan for blowing outdoor air to the outdoor heat exchanger 14 is provided in the vicinity of the outdoor heat exchanger 14.

The expansion mechanism 15 is arranged between the outdoor heat exchanger 14 and the indoor heat exchanger 11 in the refrigerant pipe 10 of the refrigerant circuit 4, expands the inflowing refrigerant, and reduces the pressure to a predetermined pressure. As the expansion mechanism 15, for example, an electronic expansion valve having a variable opening degree or a capillary tube can be adopted.

The accumulator 16 is arranged between the suction port of the compressor 12 and the four-way switching valve 17 in the refrigerant circuit 4, and separates the inflowing refrigerant into gas and liquid. The gas refrigerant separated by the accumulator 16 is sucked into the compressor 12.

The four-way switching valve 17 can be switched between the first state shown by the solid line and the second state shown by the broken line in FIG. When the air conditioner 1 performs the cooling operation, the four-way switching valve 17 is switched to the first state, and when the air conditioning device 1 performs the heating operation, the four-way switching valve 17 is switched to the second state.

(Composition of refrigerant piping)
FIG. 2 is a cross-sectional view showing a connection portion between the first pipe and the second pipe of the refrigerant pipe.
The refrigerant pipe 10A shown in FIG. 2 is connected to at least one element component X among the plurality of element components described above. The refrigerant pipe 10A has a first pipe 21 and a second pipe 22. The first pipe 21 and the second pipe 22 have the same axis O. In the present embodiment, the axis O is arranged in the vertical direction (vertical direction). In the following description, the direction along the axis O is also referred to as "tube axial direction". The radial direction centered on the axis O is also referred to as the "pipe radial direction".

(1st pipe)
The first pipe 21 has a first pipe main body 21a and a first connection portion 21b.
The first piping body 21a is made of stainless steel. The first piping main body 21a is formed of, for example, SUS304, SUS304L, SUS436L, SUS430, or the like.

The first piping main body 21a has a first large diameter portion 21a2, a first step portion 21a3, and a first small diameter portion 21a1 arranged side by side in the pipe axis direction. In the example shown in FIG. 2, the first small diameter portion 21a1 is arranged at one end (lower part) of the first piping main body 21a in the pipe axial direction. The first step portion 21a3 is arranged above the first small diameter portion 21a1. The first large diameter portion 21a2 is arranged above the first small diameter portion 21a1.

The first pipe main body 21a forms a first small diameter portion 21a1 and a first step portion 21a3 by reducing one end portion of a pipe having an outer diameter D in the pipe axial direction in the pipe diameter direction, and the diameter of this pipe. The portion where is not reduced is defined as the first large diameter portion 21a2.

The first connecting portion 21b is formed of a pipe separate from the first piping main body 21a. Hereinafter, the first connection portion 21b is also referred to as a “first connection pipe”. In FIG. 2, (p) representing a “tube” is attached to the first connecting pipe 21b. The first connecting pipe 21b is made of a material different from that of the first pipe main body 21a. The first connecting pipe 21b of this embodiment is made of copper. The term "copper" as used herein is "pure copper" containing 99.9% by weight or more of copper as a main component. The first connecting pipe 21b is a straight pipe having a constant outer diameter and inner diameter. The length of the first connecting pipe 21b in the pipe axis direction is shorter than the length of the first pipe body 21a in the pipe axis direction. The length of the first connecting pipe 21b in the pipe axial direction is longer than the length of the first small diameter portion 21a1 of the first pipe main body 21a in the pipe axial direction. The inner diameter of the first connecting pipe 21b is slightly larger than the outer diameter of the first small diameter portion 21a1.

The first small diameter portion 21a1 of the first pipe main body 21a is inserted inside the first connecting pipe 21b in the pipe radial direction. The inner peripheral surface of the first connecting pipe 21b and the outer peripheral surface of the first small diameter portion 21a1 are arranged so as to face each other in the pipe radial direction. The inner peripheral surface of the first connecting pipe 21b and the outer peripheral surface of the first small diameter portion 21a1 are brazed by the first brazing material B1. In FIG. 2, the thickness of the first brazed material B1 in the pipe radial direction is exaggerated in order to show the brazed portion in an easy-to-understand manner. The same applies to the second brazing material B2, which will be described later. Similarly, in FIGS. 3 to 16, the thicknesses of the brazing members B1 and B2 in the pipe radial direction are exaggerated.

FIG. 3 is an enlarged cross-sectional view of part A in FIG.
The inner peripheral surface of the first connecting pipe 21b and the outer peripheral surface of the first small diameter portion 21a1 are connected by "in-furnace brazing". This is due to the following reasons.
First, since stainless steel, which is the material of the first piping body 21a, has a passivation film (oxide film) formed on its surface, it is manually brazed such as torch brazing (hereinafter, also referred to as "hand brazing"). ) Is required to remove the oxide film. Since the refrigerant flows through the refrigerant circuit 4 which is a closed circuit, if the flux remains in the refrigerant pipe 10A, the flux is mixed with the refrigerant, and the refrigerant itself and the element component X into which the refrigerant flows (for example, a compressor) It may adversely affect the performance of 12). Therefore, it is essential to remove the flux after brazing.

Stainless steel, which is the material of the first piping body 21a, undergoes embrittlement called sensitization when heat is applied. Sensitization is a phenomenon in which chromium is bonded to carbon in stainless steel and chromium is precipitated at grain boundaries to form a portion having a low chromium component, resulting in deterioration of corrosion resistance and the like. This sensitization is known in the temperature range where it is likely to occur and the heat application time.

In-furnace brazing is a method of performing brazing in a predetermined gas atmosphere, for example, a hydrogen gas atmosphere in which an oxide film can be removed inside a continuous furnace or the like. Therefore, it is possible to braze stainless steel without using flux. Therefore, the work of removing the flux after brazing becomes unnecessary. In the brazing in the furnace, the brazing temperature and the brazing time can be easily controlled, so that the brazing can be performed at a temperature and time at which the occurrence of sensitization can be suppressed. By using SUS304L, which has a smaller amount of carbon than SUS304, as the first piping main body 21a, it is possible to suppress the sharpening of the first piping main body 21a.

As shown in FIG. 3, the first connecting pipe 21b has a protruding portion 21b1 protruding in the pipe axial direction from the first small diameter portion 21a1 which is an end portion of the first piping main body 21a. The protrusion amount T1 of the protrusion 21b1 is, for example, 0.1 mm or more and 25 mm or less. Preferably, the protrusion amount T1 is 1.0 mm or more and 5.0 mm or less. More preferably, the protrusion amount T1 is 2.0 mm or more and 3.0 mm or less. The protrusion amount T1 of the present embodiment is smaller than the overlap amount R1 of the first pipe main body 21a and the first connecting pipe 21b in the pipe radial direction. This overlapping amount R1 is, for example, 7.0 mm.

(2nd pipe)
As shown in FIGS. 2 and 3, the second pipe 22 is connected to one end (lower end) of the first pipe 21 in the pipe axial direction. The second pipe 22 protrudes from the element component X such as the compressor 12 and constitutes a part of the element component X and a part of the refrigerant pipe 10A. The second pipe 22 of the present embodiment has a second pipe main body 22a and a second connection portion 22b.

The second pipe body 22a is made of stainless steel, which is the same material as the first pipe body 21a of the first pipe 21. The second piping main body 22a has a second large diameter portion 22a2, a second step portion 22a3, and a second small diameter portion 22a1 arranged side by side in the pipe axis direction. The second large diameter portion 22a2 is arranged at one end (upper portion) of the second piping main body 22a in the pipe axial direction. The second small diameter portion 22a1 is arranged at the other end (lower portion) of the second piping main body 22a in the pipe axial direction. The lower end of the second small diameter portion 22a1 is directly connected to and fixed to the element component X. A second step portion 22a3 is arranged between the second large diameter portion 22a2 and the second small diameter portion 22a1.

The second pipe body 22a forms a second large diameter portion 22a2 and a second step portion 22a3 by expanding one end of a pipe having an outer diameter D in the pipe diameter direction, and the diameter of this pipe is expanded. The portion that does not exist is the second small diameter portion 22a1.

The second connecting portion 22b is composed of a plating layer applied to the inner peripheral surfaces of the second large diameter portion 22a2 and the second stepped portion 22a3 of the second piping main body 22a. The second connecting portion 22b is made of a material different from that of the second piping main body 22a, and is made of the same material as the first connecting pipe 21b. The second connection portion 22b of the present embodiment is made of copper. In FIG. 2, (m) representing a “plating layer” is attached to the second connecting portion 22b.

The second large diameter portion 22a2 of the second piping main body 22a is arranged so that the opening faces upward. The inner diameter of the second large diameter portion 22a2 is slightly larger than the outer diameter of the first connecting pipe 21b in the first pipe 21. Then, the first connecting pipe 21b of the first pipe 21 is inserted inside the second large diameter portion 22a2 in the pipe radial direction. The second connecting portion 22b provided on the inner peripheral surface of the second large diameter portion 22a2 and the outer peripheral surface of the first connecting pipe 21b are arranged so as to face each other in the pipe radial direction. The protruding portion 21b1 of the first connecting pipe 21b comes into contact with the second stepped portion 22a3 of the second piping main body 22a (substantially, the plating layer (second connecting portion 22b) applied to the second stepped portion 22a3). ing.

The second connecting portion 22b and the first connecting pipe 21b are brazed by the second brazing material B2. This brazing is hand brazing such as torch brazing (burner brazing). Since both the first connecting pipe 21b and the second connecting portion 22b are made of copper, they can be easily connected by brazing using an inexpensive brazing material such as phosphor copper brazing.

The first pipe 21 and the second pipe 22 are relatively positioned with respect to the pipe axis direction when the protruding portion 21b1 of the first connecting pipe 21b comes into contact with the second step portion 22a3 of the second pipe main body 22a. As a result, the brazing work can be performed more easily.

As shown in FIG. 3, the first connecting pipe 21b overlaps with the second pipe main body 22a in the pipe radial direction in the range indicated by R2. The overlap amount R2 has substantially the same dimensions as the overlap amount R1 between the first connecting pipe 21b and the first pipe main body 21a. The first connecting pipe 21b protrudes from the second pipe main body 22a in the pipe axial direction. The protruding amount T2 of the first connecting pipe 21b is smaller than the overlapping amount R2. The protrusion amount T2 is, for example, 2 mm or more and 3 mm or less.

The lower end of the first pipe body 21a and the upper end of the second pipe body 22a overlap in the pipe radial direction. The amount of overlap R3 between the first piping body 21a and the second piping body 22a is, for example, 5.0 mm. The first connecting pipe 21b is placed in a high temperature environment in the furnace when brazing with the first pipe main body 21a. Therefore, the strength of the first connecting pipe 21b may decrease due to the coarsening of copper crystal grains. In the present embodiment, the first connecting pipe 21b having reduced strength is provided in the refrigerant pipe 10A by arranging the stainless steel first pipe main body 21a and the second pipe main body 22a so as to overlap each other in the pipe radial direction. It does not exist alone. In other words, the first connecting pipe 21b overlaps at least one of the first pipe main body 21a and the second pipe main body 22a in the pipe radial direction. Therefore, the decrease in the strength of the first connecting pipe 21b is compensated by the first pipe main body 21a and the second pipe main body 22a.

In the present embodiment, the first connecting pipe 21b has a protruding portion 21b1 protruding from the first pipe main body 21a in the pipe axis direction. However, in FIG. 3, the first connecting pipe 21b is tentatively moved in the pipe axis direction. Assuming that the first connecting pipe 21b is formed short and the first connecting pipe 21b is retracted upward without protruding from the first pipe main body 21a, the second large diameter portion 22a2 of the second pipe 122 and the first small diameter portion 21a1 of the first pipe 121 are assumed. A slight space is created between the lower end of the pipe and the pipe diameter direction, and the amount of overlap R2 between the first connecting pipe 121b and the second pipe 122 is also reduced. Therefore, the connection strength between the first connection pipe 121b and the second pipe 122 may decrease.

In the present embodiment, as shown in FIG. 3, since the first connecting pipe 21b has a protruding portion 21b1 protruding from the first pipe main body 21a in the pipe axis direction, the second pipe 22 and the first pipe 21 No space is formed between the first pipe 21 and the second pipe main body 22a, and the amount of overlap R2 between the first pipe 21b and the second pipe main body 22a can be increased to increase the connection strength between the first pipe 21 and the second pipe 22. it can.

As the second brazing material B2, a material having a melting point lower than that of the first brazing material B2 is used. Therefore, for example, when the element component X is replaced, the connecting portion between the first pipe 21 and the second pipe 22 is set at a temperature higher than the melting point of the second brazing material B2 and lower than the melting point of the first brazing material B1. By heating, only the second brazing material B2 can be melted without melting the first brazing material B1, and the second pipe 22 can be removed from the first pipe 21. Therefore, in the first pipe 21, the first connection pipe 21b remains connected to the first pipe main body 21a, and the second pipe 22 of the new element component X is connected to the first connection pipe 21b. Is possible.

The first large diameter portion 21a2 of the first pipe 21 and the second small diameter portion 22a1 of the second pipe 22 have a common outer diameter D. Therefore, in the manufacturing process of the refrigerating apparatus 1, the jigs used for fixing, holding, handling, etc. of each pipe can be standardized. When the inner diameter of the first large diameter portion 21a2 and the inner diameter of the second small diameter portion 22a1 are common, the pressure fluctuation of the refrigerant flowing through the refrigerant pipe 10A can be reduced.

(Valve unit)
FIG. 17 is a front view showing a valve unit in which a four-way switching valve and a refrigerant pipe are integrated.
The four-way switching valve 17 has a valve body 17a constituting an outer shell, a valve body housed inside the valve body 17a, and the like. The valve body 17a is made of stainless steel.

The valve body 17a is provided with four first to fourth ports 17b1 to 17b4, which are composed of short pipes and form an inlet / outlet for a refrigerant. These first to fourth ports 17b1 to 17b4 are made of stainless steel. One ends of the first to third refrigerant pipes 10A1 to 10A3 and the fourth refrigerant pipe 10B are connected to the first to fourth ports 17b1 to 17b4, respectively.

The first to third refrigerant pipes 10A to 10A3 are the refrigerant pipes of the present embodiment described with reference to FIGS. 2 and 3. The first pipe 21 of the first to third refrigerant pipes 10A1 to 10A3 has a first pipe main body 21a and a first connection pipe 21b. One end of the first piping main body 21a is connected to the three first to third ports 17b1 to 17b3. A first connecting pipe 21b is provided at the other end of the first pipe main body 21a. Since the first pipe body 21a is made of stainless steel, the connection between the first to third ports 17b1 to 17b3 and the first pipe body 21a is a connection between stainless steels.

One end of the fourth refrigerant pipe 10B is connected to the remaining one fourth port 17b4. Unlike the first to third refrigerant pipes 10A to 10A3, the fourth refrigerant pipe 10B is made of only stainless steel. One end of the muffler 13 is connected to the other end of the fourth refrigerant pipe 10B. The muffler 13 is also made of stainless steel. Therefore, the connection between the fourth refrigerant pipe 10B and the muffler 13 is a connection between stainless steels.

A fifth refrigerant pipe 10A5 is connected to the other end of the muffler 13. The fifth refrigerant pipe 10A5 is the refrigerant pipe of the present embodiment described with reference to FIGS. 2 and 3 in the same manner as the first to third refrigerant pipes 10A1 to 10A3. One end of the first pipe 21 of the fifth refrigerant pipe 10A5 is connected to the other end of the muffler 13. A first connecting pipe 21b is provided at the other end of the first pipe 21. Since the first pipe body 21a is made of stainless steel, the connection between the muffler 13 and the first pipe body 21a is a connection between stainless steels.

A joint pipe 31 is attached to the outer peripheral surface of the first pipe main body 21a of the third refrigerant pipe 10A3. The joint pipe 31 is made of a material different from that of the first pipe main body 21a and is made of the same material as the first connecting pipe 21b. The joint pipe 31 of this embodiment is made of copper. Another refrigerant pipe 32 made of the same material as the joint pipe 31 is connected to the joint pipe 31. The other refrigerant pipe 32 is made of copper and has a diameter smaller than that of the first pipe main body 21a.

In the valve unit U shown in FIG. 17, the connection between the stainless steels and the connection between the stainless steels and the copper are both performed by brazing in the furnace. In the present embodiment, the entire valve unit U in which the four-way switching valve 17, the muffler 13, the refrigerant pipes 10A and 10B, and the joint pipe 31 are temporarily assembled is put into the furnace, and each connection portion is brazed in the furnace at the same time. ..

Since the joint pipe 31 and the refrigerant pipe 32 are connected to each other by copper, they are connected by hand brazing instead of brazing in the furnace. The refrigerant pipe 32 is called a service port, and is used for attaching a functional component such as a pressure sensor at the time of maintenance or inspection of the refrigerating device 1. If the refrigerant pipe 32 is made of stainless steel, it can be brazed in the furnace together with other pipes and the like as described above. However, since the refrigerant pipe 32 has a smaller diameter than the other refrigerant pipes 10A, if it is made of stainless steel, there is an adverse effect that the manufacturing cost is rather high in order to obtain a predetermined accuracy. Therefore, in the present embodiment, the refrigerant pipe 32 is made of copper, and only the copper joint pipe 31 is connected to the refrigerant pipe 10A by brazing in the furnace. As a result, the refrigerant pipe 32 can be connected to the refrigerant pipe 10A via the joint pipe 31 by manual brazing without causing a decrease in the strength of the refrigerant pipe 32.

The joint pipe 31 and the refrigerant pipe 32 are not limited to the third refrigerant pipe 10A3, and may be provided in other refrigerant pipes 10A1, 10A2, 10A5, 10A6. The joint pipe 31 and the refrigerant pipe 32 are not limited to the first pipe 21 but may be provided in the second pipe 22.

FIG. 18 is a perspective view showing a state in which the valve unit is connected to the element component.
Specifically, FIG. 18 shows a state in which the valve unit U shown in FIG. 17 is connected to the compressor 12 as the element component X and the accumulator 16. The discharge pipe 12a of the compressor 12 is composed of a second pipe 22 of the fifth refrigerant pipe 10A5. The first pipe 21 of the fifth refrigerant pipe 10A5 connected to the muffler 13 of the valve unit U is connected to the second pipe 22. Therefore, the compressor 12 is connected to the four-way switching valve 17 via the fifth refrigerant pipe 10A5, the muffler 13, and the fourth refrigerant pipe 10B.

The inflow pipe 16a of the accumulator 16 constitutes the second pipe 22 of the first refrigerant pipe 10A1. The first pipe 21 of the first refrigerant pipe 10A1 is connected to the second pipe 22.
The outflow pipe 16b of the accumulator 16 and the suction pipe 12b of the compressor 12 are connected by a sixth refrigerant pipe 10A6. Although the sixth refrigerant pipe 10A6 is not included in the valve unit U, it is the refrigerant pipe of the present embodiment described with reference to FIGS. 2 and 3. The outflow pipe 16b of the accumulator 16 and the suction pipe 12b of the compressor 12 both form the second pipe 22 of the sixth refrigerant pipe 10A6. Both ends of the first pipe 21 of the sixth refrigerant pipe 10A6 are manually brazed to the second pipe 22, respectively.

The first pipe 21 of the second and third refrigerant pipes 10A2 and 10A3 connected to the other two second and third ports 17a2 and 17a3 of the four-way switching valve 17 is a closing valve 18G shown in FIG. 1, respectively. Is connected to the gas side header of the outdoor heat exchanger 14.

FIG. 19 is a perspective view showing a state in which the valve unit according to the comparative example is connected to the element component. In the valve unit shown in FIG. 19, the valve body 17a and ports 17b1 to 17b4 of the four-way switching valve 17 and the refrigerant pipe 110 are made of copper. In the case of this comparative example, the vibration of the compressor 12 is transmitted to the refrigerant pipe 110, but since the copper refrigerant pipe 110 has low strength, a structure for absorbing the vibration is required. For example, it is necessary to partially bend the refrigerant pipe 110 to form the loop portion 110a or to form the bypass portion 110b. Therefore, the structure of the refrigerant pipe 110 becomes complicated, and a large space is required for arranging the refrigerant pipe 110.

In the case of the present embodiment, as shown in FIG. 18, of the first, third, fifth, and sixth refrigerant pipes 10A1 to 10A3, 10A5, and 10A6, the portions that bear the strength (first, second pipe main bodies 21a, 22a). ) Are all made of stainless steel, and the fourth refrigerant pipe 10B is also made of stainless steel. Since these refrigerant pipes 10A1 to 10A3, 10A5, 10A6, and 10B have higher strength than the copper refrigerant pipe 110 shown in FIG. 19, it is not necessary to provide a special structure for absorbing the vibration of the compressor 12. Therefore, the fifth and sixth refrigerant pipes 10A5 and 10A6 connected to the compressor 12 can be formed into a simple structure without being greatly bent and can be arranged in a small space.

Further, in the refrigerant pipes 10A1 to 10A3, 10A5, 10A6, 10B, if a part in the pipe axis direction in which copper is present alone is included, stress is concentrated on that part and causes damage. Since the refrigerant pipes 10A1 to 10A3, 10A5, 10A6, 10B of the embodiment do not have a portion where copper is present alone in a part in the pipe axial direction, damage due to stress concentration can be suppressed.

The compressor 12 and the accumulator 16 described above are usually fixed to the bottom plate of the casing in the outdoor unit 2, but the four-way switching valve 17 is arranged at a position away from the bottom plate and is attached to the casing or the like of the outdoor unit 2. Not directly fixed. Therefore, during transportation of the refrigerating apparatus 1, the four-way switching valve 17 tends to vibrate, and the first to fourth refrigerant pipes 10A1 to 10A3 and 10B connected to the four-way switching valve 17 are subjected to a load due to the vibration. Will be done. However, in the first to third refrigerant pipes 10A to 10A3, the parts mainly responsible for the strength (first and second pipe main bodies 21a and 22a) are all made of stainless steel, and the fourth refrigerant pipe 10B is also made of stainless steel. , Deformation and damage can be suppressed.

[Second Embodiment]
FIG. 4 is a cross-sectional view showing a connecting portion between the first pipe and the second pipe of the refrigerant pipe according to the second embodiment.
The refrigerant pipe 10A of the present embodiment has a third pipe 23 in addition to the first pipe 21 and the second pipe 22. The third pipe 23 has the same axis O as the first pipe 21 and the second pipe 22.

The first pipe 21 of the present embodiment is formed shorter in the pipe axis direction than the first pipe 21 of the first embodiment. The first pipe 21 is arranged between the second pipe 22 and the third pipe 23 in the pipe axial direction. Therefore, the first pipe 21 of the present embodiment has a function as a joint for connecting the second pipe 22 and the third pipe 23.

The third pipe 23 is connected to the first large diameter portion 21a2 in the first pipe main body 21a of the first pipe 21. The third pipe 23 is made of stainless steel, which is the same material as the first pipe main body 21a. The first pipe main body 21a and the third pipe 23 are connected by welding such as TIG welding. However, the first pipe main body 21a and the third pipe 23 may be connected by brazing. The third pipe 23 has the same outer diameter D as the first large diameter portion 21a2 of the first pipe main body 21a.

In the first pipe 21 of the refrigerant pipe 10A of the first embodiment described above, since the first large diameter portion 21a2 of the first pipe main body 21a is formed long in the pipe axis direction, the first pipe 21 becomes large and the first pipe 21 becomes larger. When brazing the 1 pipe main body 21a and the 1st connecting pipe 21b in the furnace, the handling of the 1st pipe 21 becomes complicated. In the first pipe 21 of the present embodiment, the first pipe 21a is formed short, and the first pipe 21 itself is used as a "joint" connecting the second pipe 22 and the third pipe 23, whereby the first pipe 21 Has been downsized to facilitate the work of brazing in the furnace. Further, by downsizing the first pipe 21, the number of the first pipes 21 that can be put into the furnace at one time can be increased, so that the production efficiency can be improved.

FIG. 5 is a cross-sectional view showing a state before brazing the first pipe main body of the first pipe and the first connecting pipe.
In the present embodiment, in order to braze the first piping main body 21a and the first connecting pipe 21b, first, the first brazing material B1 is placed outside the first small diameter portion 21a1 of the first piping main body 21a in the pipe radial direction. Fit the ring brazing Ba that becomes. Next, the first connecting pipe 21b is fitted on the outside of the first small diameter portion 21a1 in the pipe radial direction, and the ring wax Ba is sandwiched between the first connecting pipe 21b and the first stepped portion 21a3. With the first pipe body 21a on the upper side and the first connecting pipe 21b on the lower side, the ring wax Ba is melted by putting the first pipe body 21a and the first connecting pipe 21b into a high-temperature furnace, and the arrow a. As shown by, the first brazing material B1 is poured into the gap between the outer peripheral surface of the first small diameter portion 21a1 and the inner peripheral surface of the first connecting pipe 21b.

In this way, by sandwiching the ring brazing Ba between the first connecting pipe 21b and the first stepped portion 21a3, the first connecting pipe 21b, the first piping main body 21a, and the ring brazing Ba are relatively positioned. Brazing can be done. Further, if the first pipe 21 is formed long as in the first embodiment, the first pipe 21 can be put into the furnace only in a sideways posture, but the first pipe 21 is downsized as in the present embodiment. If this is done, brazing can be performed with the axis of the first pipe 21 (first pipe main body 21a and first connecting pipe 21b) facing in the vertical direction as described above, so that the first small diameter portion can be brazed. The first brazing material B1 can be uniformly poured into the gap between the outer peripheral surface of the 21a1 and the inner peripheral surface of the first connecting pipe 21b.

(Modification example of the first piping body 21a)
FIG. 6 is a cross-sectional view showing a modified example of the first piping main body.
In the modified example shown in FIG. 6, the end portion 23a of the third pipe 23 is inserted inside the first large diameter portion 21a2 formed in the first pipe main body 21a of the first pipe 21, and the first large diameter portion 21a2 and The third pipe 23 is connected by welding.

In the example shown in FIG. 6A, the first pipe main body 21a and the third pipe 23 of the first pipe 21 are welded all around at one place in the pipe axial direction indicated by Y1. The welded portion Y1 is located at the tip of the first large diameter portion 21a2. By performing welding from the outer peripheral side of the first large diameter portion 21a2 at the welding portion Y1, the first large diameter portion 21a2 and the third pipe 23 are melted and both are connected.

The welded portion Y1 is located at the end of the first pipe 21 opposite to the second pipe 22 in the range where the first pipe main body 21a and the third pipe 23 overlap in the pipe radial direction. In other words, the welded portion Y1 is located on the side closer to the atmosphere (outside side of the refrigerant pipe 10A) in the range where the first pipe main body 21a and the third pipe 23 of the first pipe 21 overlap in the pipe radial direction. ing. Therefore, the welding work can be easily performed while checking the connection state between the first pipe main body 21a of the first pipe 21 and the third pipe 23. Further, as compared with the case where the butt portion between the first pipe main body 21a and the third pipe 23 is welded as in the embodiment shown in FIG. 4, in this modified example, the welding area can be widened. The strength of the connecting portion between the 1-pipe main body 21a and the 3rd pipe 23 can be increased, and the structure can withstand a large stress.

In the example shown in FIG. 6B, the first pipe main body 21a and the third pipe 23 of the first pipe 21 are welded all around at two locations in the pipe axial direction indicated by Y1 and Y2. These welds Y1 and Y2 are located at both ends of the first large diameter portion 21a2 in the pipe axial direction.

As shown in FIG. 6A, when the first large diameter portion 21a2 and the third pipe 23 are connected only at the welded portion Y1, the end portion 23a of the third pipe 23 due to the flow of the refrigerant in the refrigerant pipe 10A or the like. If a minute movement occurs in the surface, stress may be concentrated near the boundary between the first large diameter portion 21a2 and the first stepped portion 21a3. Therefore, in the example shown in FIG. 6B, the movement of the third pipe 23 is restricted by connecting the first large diameter portion 21a2 and the third pipe 23 even at the welded portion Y2, and the first pipe 21 It is possible to suppress the stress concentration generated in the first piping body 21a.

In the example shown in FIG. 6C, similarly to the example shown in FIG. 6A, the third pipe 23 is formed inside the first large diameter portion 21a2 formed in the first pipe main body 21a of the first pipe 21. The end portion 23a is inserted, and the first large diameter portion 21a2 and the third pipe 23 are connected by welding. The first large diameter portion 21a2 of this modified example is formed shorter in the pipe axis direction than the first large diameter portion 21a2 shown in FIG. 6, and is formed with the first pipe main body 21a and the third pipe 23 of the first pipe 21. Is welded all around at one location Y3 in the pipe axis direction. In this modification, since the first large diameter portion 21a2 is formed short, the entire range of the first large diameter portion 21a2 in the pipe axial direction is connected to the third pipe 23 even when welding is performed at one location Y3. Can be done.

In each of the examples shown in FIGS. 6A to 6C, the first small diameter portion 21a1 of the first piping body 21a is formed short in the pipe axis direction, or the first connecting pipe 21b is long in the pipe axis direction. By forming the first connecting pipe 21b, the end portion of the first connecting pipe 21b may be brought into contact with the first stepped portion 21a3 to position the first connecting pipe 21b in the pipe axial direction with respect to the first pipe main body 21a.

7 to 9 are cross-sectional views showing a further modified example of the first piping main body.
In the example shown in FIG. 7A, the first pipe main body 21a of the first pipe 21 is composed of a straight pipe having a constant outer diameter. On the other hand, the third pipe 23 has a third small diameter portion 23a1, a third large diameter portion 23a2, and a third step portion 23a3. The third small diameter portion 23a1 is arranged at the end of the third pipe 23 and is inserted inside the first pipe main body 21a. The first pipe body 21a and the third pipe 23 are welded all around at one location Y4 in the pipe axis direction. This welding is performed over the entire range of the third small diameter portion 23a1 in the pipe axial direction.

In the example shown in FIG. 7B, the first pipe main body 21a of the first pipe 21 is composed of a straight pipe having a constant outer diameter. The third pipe 23 is also composed of a straight pipe having at least an end having the same outer diameter as the first pipe main body 21a. The first pipe main body 21a and the third pipe 23 are welded on the abutted surface Y5.

In the modified example shown in FIG. 8, the first pipe main body 21a of the first pipe 21 has a fourth large diameter portion 21a4 having a diameter further larger than that of the first large diameter portion 21a2, and the first large diameter portion 21a2 and the first large diameter portion 21a2. A fourth stepped portion 21a5 arranged between the four large diameter portions 21a4 is formed. The end of the third pipe 23 is inserted into the fourth large diameter portion 21a4, and the fourth large diameter portion 21a4 and the third pipe 23 are connected by welding.

In the example shown in FIG. 8A, the fourth large diameter portion 21a4 and the third pipe 23 of the first pipe 21 are welded all around at one location in the pipe axial direction indicated by Y1. The welded portion Y1 is located at the tip of the fourth large diameter portion 21a4. By performing welding from the outer peripheral side of the fourth large diameter portion 21a4 at the welded portion Y1, the fourth large diameter portion 21a4 and the third pipe 23 are melted and both are connected.

The welded portion Y1 is located at the end of the first pipe 21 opposite to the second pipe 22 in the range where the first pipe main body 21a and the third pipe 23 overlap in the pipe radial direction. In other words, the welded portion Y1 is located on the side closer to the atmosphere (outside side of the refrigerant pipe 10A) in the range where the first pipe main body 21a and the third pipe 23 of the first pipe 21 overlap in the pipe radial direction. ing. Therefore, the welding work can be easily performed while checking the connection state between the first pipe 21 and the third pipe 23. Further, as compared with the case where the butt portion between the first pipe main body 21a and the third pipe is welded as in the embodiment shown in FIG. 4, in this modified example, the welding area can be widened, and the first The strength of the connecting portion between the pipe main body 21a and the third pipe can be increased, and the structure can withstand a large stress.

In the example shown in FIG. 8B, the first pipe main body 21a and the third pipe 23 of the first pipe 21 are welded all around at two locations in the pipe axial direction indicated by Y1 and Y2. These welded portions Y1 and Y2 are located at both ends of the fourth large diameter portion 21a4 in the pipe axial direction.

As shown in FIG. 8A, when the fourth large diameter portion 21a4 and the third pipe 23 are connected only at the welded portion Y1, the end portion 23a of the third pipe 23 due to the flow of the refrigerant in the refrigerant pipe 10A or the like. If a minute movement occurs in the surface, stress may be concentrated near the boundary between the fourth large diameter portion 21a4 and the fourth stepped portion 21a5. Therefore, in the example shown in FIG. 8B, the movement of the third pipe 23 is restricted by connecting the fourth large diameter portion 21a4 and the third pipe 23 even at the welded portion Y2, and the first pipe 21 is used. The resulting stress concentration can be suppressed.

In the example shown in FIG. 9, the fourth large diameter portion 21a4 and the fourth stepped portion 21a5 are formed on the first pipe main body 21a of the first pipe 21 as in the example shown in FIG. A third pipe 23 is inserted into the fourth large diameter portion 21a4, and the fourth large diameter portion 21a4 and the third pipe 23 are connected by welding. The fourth large-diameter portion 21a4 of this modification is formed shorter in the pipe axis direction than the fourth large-diameter portion 21a4 shown in FIG. 8, and the first pipe 21 and the third pipe 23 are formed in the pipe axis direction. It is welded all around at one location Y3. In this modification, since the 4th large diameter portion 21a4 is formed short, the entire range of the 4th large diameter portion 21a4 in the pipe axial direction is connected to the 3rd pipe 23 even if welding is performed at one location Y3. Can be done.

[Third Embodiment]
FIG. 10 is a cross-sectional view showing a connecting portion between the first pipe and the second pipe of the refrigerant pipe according to the third embodiment.
The structure of the first pipe 21 of the refrigerant pipe 10A of the present embodiment is different from that of the first embodiment. The first pipe main body 21a of the first pipe 21 has a constant inner diameter and outer diameter D, and does not have the first large diameter portion, the first small diameter portion, and the first step portion as in the first embodiment.

Also in this embodiment, substantially the same effect as that of the first embodiment is obtained. Further, since the first pipe 21 does not require the first small diameter portion 21a1, there is an advantage that the processing becomes easy. On the other hand, in the present embodiment, it is necessary to enlarge the outer diameter of the second large diameter portion 22a2 of the second pipe main body 22a in the second pipe 22 to be larger than that of the second large diameter portion 22a2 of the first embodiment. , The processing of the second piping body 22a becomes difficult. In this respect, the first embodiment is more advantageous.

[Fourth Embodiment]
FIG. 11 is a cross-sectional view showing a connecting portion between the first pipe and the second pipe of the refrigerant pipe according to the fourth embodiment.
The structure of the first pipe 21 of the refrigerant pipe 10A of the present embodiment is different from that of the first embodiment. The first connecting pipe 21b of the first pipe 21 has a larger protrusion amount T1 in the pipe axis direction of the protruding portion 21b1 protruding from the first pipe main body 21a than the overlapping amount R1 with the first pipe main body 21a. The protrusion amount T1 of the protrusion 21b1 is larger than the overlap amount R2 of the first connecting pipe 21b and the second pipe 22 in the pipe axis direction. Therefore, the refrigerant pipe 10A of the present embodiment has a region R4 in which the first connecting pipe 21b is independently present in the middle of the pipe axial direction.

Also in this embodiment, substantially the same effect as that of the first embodiment is obtained. However, in the refrigerant pipe 10A of the present embodiment, since the first connecting pipe 21b, which may be weakened by brazing in the furnace, has a region R4 in which the first connecting pipe 21b exists independently, the first embodiment is performed in terms of strength. The form is more advantageous.

[Fifth Embodiment]
FIG. 12 is an enlarged cross-sectional view showing a connection portion between the first pipe and the second pipe of the refrigerant pipe according to the fifth embodiment.
The structure of the second connecting portion 22b of the second pipe 22 of the refrigerant pipe 10A of the present embodiment is different from that of the first embodiment. The second connecting portion 22b is plated on the inner peripheral surface and the tip surface (upper end surface in FIG. 12) of the second large diameter portion 22a2 of the second piping body 22a and the inner peripheral surface of the second stepped portion 22a3. It consists of layers. That is, the present embodiment is different from the first embodiment in that the second connecting portion 22b has a portion 22b1 that covers the tip surface of the second large diameter portion 22a2.

In the first embodiment, since the second connecting portion 22b is not provided on the tip surface of the second large diameter portion 22a2, even if brazing is performed on the tip surface of the second large diameter portion 22a2, the first 2 The brazing material B2 is repelled, and it is difficult to expand the brazing area. In the present embodiment, since a part 22b1 of the second connection part 22b is provided on the tip surface of the second large diameter part 22a2, the brazing area is expanded to a position covering the part 22b1 and the second pipe 22 The connection between the pipe and the first pipe 21 can be further strengthened.

The structure of the second connecting portion 22b in FIG. 12 can also be applied to the second to fourth embodiments described above.

[Sixth Embodiment]
FIG. 13 is a cross-sectional view showing a connecting portion between the first pipe and the second pipe of the refrigerant pipe according to the sixth embodiment.
In the refrigerant pipe 10A of the present embodiment, the configuration of the second pipe 22 is different from that of the first embodiment. The second pipe 22 includes a second pipe main body 22a and a second connection portion 22b, as in the first embodiment. However, the second connecting portion 22b is composed of a plating layer applied not only to one end of the second piping main body 22a but also to the entire outer surface of the second piping main body 22a.

In the present embodiment, when the second connecting portion 22b made of the plating layer is provided on the second piping main body 22a, the entire second piping main body 22a may be immersed in the plating bath, which facilitates the plating operation. Other configurations are the same as in the first embodiment.
The second connecting portion 22b may be configured by applying a plating layer to the inner peripheral surface and the outer peripheral surface of the second large diameter portion 22a2 and the second stepped portion 22a3 of the second piping main body 22a.

[7th Embodiment]
FIG. 14 is a cross-sectional view showing a connecting portion between the first pipe and the second pipe of the refrigerant pipe according to the seventh embodiment.
In the refrigerant pipe 10A of the present embodiment, the first connection portion 21b of the first pipe 21 is a plating layer applied to the end portion of the first pipe main body 21a. The second connection portion 22b of the second pipe 22 is a pipe (second connection pipe 22b) attached to the end of the second pipe main body 22a. Both the first piping body 21a and the second piping body 22a are made of stainless steel. Both the first connecting portion 21b and the second connecting pipe 22b are made of copper.

In the present embodiment, the stainless steel second pipe body 22a and the copper second connecting pipe 22b are connected by brazing in the furnace by the first brazing material B1. Further, the copper second connecting pipe 22b and the copper first connecting portion 21b are manually brazed by the second brazing material B2. The melting point of the first brazing material B1 is higher than the melting point of the second brazing material B2.

In the present embodiment, in order to disconnect the first pipe 21 and the second pipe 22, the connecting portion between the two is heated at a temperature lower than the melting point of the first brazing material B1 and higher than the melting point of the second brazing material B2. Then, by melting the second brazing material B2 without melting the first brazing material B1, the connection between the first pipe 21 and the second pipe 22 can be disconnected. In the second pipe 22, the second connecting pipe 22b remains connected to the second pipe main body 22a, so that the new first pipe 21 can be connected by using the second connecting pipe 22b.

[8th Embodiment]
FIG. 15 is a cross-sectional view showing a connecting portion between the first pipe and the second pipe of the refrigerant pipe according to the eighth embodiment.
In the refrigerant pipe 10A of the present embodiment, the first connection portion 21b of the first pipe 21 and the second connection portion 22b of the second pipe 22 are both pipes (first connection pipe 21b, second connection pipe 22b). is there. Both the first piping body 21a and the second piping body 22a are made of stainless steel. Both the first connecting pipe 21b and the second connecting pipe 22b are made of copper.

In the present embodiment, the stainless steel first pipe body 21a and the copper first connecting pipe 21b are connected by brazing in the furnace by the first brazing material B1. The stainless steel second pipe body 22a and the copper second connecting pipe 22b are also connected by brazing in the furnace by the first brazing material B1.
The copper first connecting pipe 21b and the copper second connecting pipe 22b are manually brazed by a second brazing material B2. The melting point of the first brazing material B1 is higher than the melting point of the second brazing material B2.

In the present embodiment, in order to disconnect the first pipe 21 and the second pipe 22, the connecting portion between the two is heated at a temperature lower than the melting point of the first brazing material B1 and higher than the melting point of the second brazing material B2. Then, by melting the second brazing material B2 without melting the first brazing material B1, the connection between the first pipe 21 and the second pipe 22 can be disconnected. In the first pipe 21, the first connection pipe 21b remains connected to the first pipe body 21a, and in the second pipe 22, the second connection pipe 22b remains connected to the second pipe body 22a. A new second pipe 22 or first pipe 21 can be connected by using the first connecting pipe 21b and the second connecting pipe 22b, respectively.

[9th Embodiment]
FIG. 16 is a cross-sectional view showing a connecting portion between the first pipe and the second pipe of the refrigerant pipe according to the ninth embodiment.
In the refrigerant pipe 10A of the present embodiment, the first connection portion 21b of the first pipe 21 is a plating layer applied to the end portion of the first pipe main body 21a. The second connection portion 22b of the second pipe 22 is a plating layer applied to the end portion of the second pipe main body 22a.

The first pipe 21 and the second pipe 22 are connected by manually brazing the first connection portion 21b and the second connection portion 22b.
In the present embodiment, the first and second connecting portions 21b and 22b can be easily provided on the first and second piping main bodies 21a and 22a.

[Other Embodiments]
In each of the embodiments described above, the first connection portion 21b of the first pipe 21 and the second connection portion 22b of the second pipe 22 are made of copper. However, these are not limited to copper and can be changed as appropriate. For example, the first connecting portion 21b and the second connecting portion 22b can be made of a copper alloy. A copper alloy is an alloy in which the properties of copper are improved by adding another metal or non-metal to copper as a main component. Copper alloy, like copper, is a member that does not require flux treatment and is easy to braze. As the copper alloy, for example, one containing 98% by weight or more of copper is adopted. More preferably, a copper alloy containing 99% by weight or more of copper is adopted.

The main components of the first connection portion 21b of the first pipe 21 and the second connection portion 22b of the second pipe 22 may be made of the same material. Therefore, the first connecting pipe 21b and the second connecting portion 22b may be made of copper, or both may be made of copper alloy, or one may be made of copper and the other may be made of copper alloy. .. When both the first connecting pipe 21b and the second connecting portion 22b are made of copper alloy, the components other than the main component may be different from each other. That is, the first connecting pipe 21b and the second connecting portion 22b may be made of materials having the same main component but different from each other. In this case as well, both can be brazed without using flux.

The first connecting portion 21b and the second connecting portion 22b may be made of aluminum or an aluminum alloy. As used herein, the term "aluminum" is "pure aluminum" containing 99.9% by weight or more of aluminum as a main component. An aluminum alloy is an alloy in which the properties of aluminum are improved by adding another metal or non-metal to aluminum as a main component. As the aluminum alloy, for example, an alloy containing 95% by weight or more of aluminum is adopted. The first connecting pipe 21b and the second connecting pipe 22b are either made of aluminum, both are made of aluminum alloy, or one is made of aluminum and the other is made of aluminum alloy. You may. When both the first connecting pipe 21b and the second connecting portion 22b are made of an aluminum alloy, components other than the main component may be different.

The second pipe 22 of each of the above embodiments is provided in the element component X and constitutes a part of the element component X, but may simply form only the refrigerant pipe 10A. The first pipe 21 may form a part of the element component X.

Although the joint pipe 31 is provided in the first pipe main body 21a of the first pipe 21, it may be provided in the second pipe main body 22a of the second pipe 22. The joint pipe 31 of the above embodiment is made of copper, but may be made of a copper alloy. The other refrigerant pipe 32 connected to the joint pipe 31 may also be made of a copper alloy. One of the joint pipe 31 and the other refrigerant pipe 32 may be made of copper, and the other may be made of a copper alloy. When both the joint pipe 31 and the other refrigerant pipe 32 are made of copper alloy, the components other than the main component may be different from each other.

The third pipe 23 in the second embodiment may be connected to the second pipe main body 22a in the second pipe 22. In this case, the second pipe 22 functions as a joint that connects the first pipe 21 and the third pipe 23.

[Action and effect of the embodiment]
(1) The refrigerant pipe 10A of each of the above embodiments includes a first pipe 21 and a second pipe 22. The first pipe 21 has a first pipe main body 21a made of stainless steel and a first connection portion 21b provided at an end portion of the first pipe main body 21a in the pipe axial direction and made of a material different from stainless steel. The second pipe 22 has a second pipe body 22a made of stainless steel and a second connection part 22b provided at the end of the second pipe body 22a in the pipe axis direction and made of the same material as the first connection part 21b. .. The first connection portion 21b and the second connection portion 22b are connected.

In the refrigerant pipe 10A having the above configuration, since the first pipe 21 and the second pipe 22 have the first connection portion 21b and the second connection portion 22b, which are different from stainless steel and are made of the same material, respectively. By connecting the 1 connection portion 21b and the second connection portion 22b by brazing or the like, the brazing of stainless steel becomes unnecessary, and the first pipe 21 and the second pipe 22 can be easily connected.

(2) The refrigerant pipe 10A of each of the above embodiments includes a first pipe 21 and a second pipe 22. The first pipe 21 has a first pipe main body 21a made of stainless steel and a first connection portion 21b provided at an end portion of the first pipe main body 21a in the pipe axial direction and made of a material different from stainless steel. The second pipe 22 is provided at the end of the second pipe body 22a made of stainless steel in the pipe axis direction and has the same main component as the first connection part 21b. It has 22b and. The first connection portion 21b and the second connection portion 22b are connected.

In the refrigerant pipe 10A having the above configuration, the first pipe 21 and the second pipe 22 each have a first connection portion 21b and a second connection portion 22b made of a material different from stainless steel and having the same main component. Therefore, by connecting the first connection portion 21b and the second connection portion 22b by brazing or the like, the brazing of stainless steel becomes unnecessary, and the first pipe 21 and the second pipe 22 can be easily connected. it can.

(3) In the refrigerant pipe 10A of the other embodiment, the first connection portion 21b and the second connection portion 22b are made of different materials having the same main component.
Even in such a case, the first pipe and the second pipe can be easily connected.

(4) In each of the above embodiments, each of the first connecting portion 21b and the second connecting portion 22b is made of copper, a copper alloy, aluminum, or an aluminum alloy. Therefore, the first pipe 21 and the second pipe 22 can be easily connected by brazing using an inexpensive brazing material.

(5) In each of the above embodiments, the end portion of the first piping main body 21a and the end portion of the second piping main body 22a are arranged so as to overlap in the pipe radial direction. Therefore, in the refrigerant pipe 10A, the first and second connecting portions 21b and 22b, which may be weakened by brazing in the furnace, do not exist independently, and the strength of the first and second connecting portions 21b and 22b is lowered. Can be supplemented by the first piping main body 21a and the second piping main body 22a.

(6) In each of the above embodiments, the first connecting portion 21b is a plating layer applied to the end of the first piping main body 21a or a pipe attached to the end of the first piping main body 21a. The second connecting portion 22b is a plating layer applied to the end portion of the second piping main body 22a, or a pipe attached to the end portion of the second piping main body 22a.

When the first connection portion 21b and the second connection portion 22b are plated layers, the first connection portion 21b and the second connection portion 22b can be easily provided at the ends of the first piping body 21a and the second piping body 22a. it can. When the first connection portion 21b and the second connection portion 22b are pipes, the first connection portion 21b and the second connection portion 21b made of a material other than stainless steel are attached to the ends of the first pipe body 21a and the second pipe body 22a made of stainless steel. The connecting portion 22b can be connected by brazing in the furnace.

(7) In the first to seventh embodiments, one connection portion of the first connection portion 21b and the second connection portion 22b is a pipe, the other connection portion is a plating layer, and the one connection portion and the said one. One pipe body provided with one connecting portion is connected by the first brazing material B1, one connecting portion and the other connecting portion are connected by the second brazing material B2, and the first brazing material B1 is connected. It has a higher melting point than the second brazing material B2. Therefore, when the connection between the first pipe 21 and the second pipe 22 is disconnected for parts replacement or the like, the temperature at which the connection portion between the two is higher than the melting point of the second brazing material B2 and lower than the melting point of the first brazing material B1 is lower. By heating with, only the second brazing material B2 can be melted, and the connection between one pipe body and the pipe which is one connection portion can be maintained. Therefore, one connection can be reused for a new connection to the other connection.

(8) In the second embodiment, one of the first pipe 21 and the second pipe 22 constitutes a joint connecting the other pipe and the other stainless steel pipe 23. Therefore, one of the pipes can be miniaturized, and the work of providing a connecting portion on the pipe main body can be easily performed.

(9) In each of the above embodiments, a joint made of the same main component as the first connecting portion 21b and the second connecting portion 22b is provided on at least one outer peripheral surface of the first piping main body 21a and the second piping main body 22a. A pipe 31 is attached, and another pipe 32 made of the same material as the joint pipe 31 is connected to the joint pipe 31. Therefore, functional parts such as sensors can be easily connected to the stainless steel pipe body via another pipe 32 made of a material different from stainless steel.

It should be noted that the present disclosure is not limited to the above examples, and is indicated by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1: Refrigerant device 4: Refrigerant circuit 10A: Refrigerant pipe 10B: Refrigerant pipe 17: Four-way switching valve (switching mechanism)
21: First pipe 21a: First pipe main body 21b: First connection (first connection pipe)
22: Second pipe 22a: Second pipe main body 22b: Second connection (second connection pipe)
23: Third pipe 31: Joint pipe 32: Refrigerant pipe B1: Wax material B2: Wax material X: Element parts

(1) The refrigerant piping of the present disclosure is
Refrigerant piping that constitutes the refrigerant circuit of the refrigeration system.
Equipped with a first pipe and a second pipe,
The first pipe has a first pipe body made of stainless steel and a first connection part provided at an end portion of the first pipe body in the pipe axial direction and made of a material different from stainless steel.
The second pipe has a second pipe body made of stainless steel and a second connection part provided at an end portion of the second pipe body in the pipe axial direction and made of the same material as the first connection part.
The first connection portion and the second connection portion are connected ,
At least one of the first connection and the second connection is a pipe.
The one connecting portion and the one piping main body provided with the one connecting portion are connected by a first brazing material.
The one connecting portion and the other connecting portion are connected by a second brazing material.
Wherein the first brazing material, that have a higher melting point than the second brazing material.
In addition, the refrigerant piping of the present disclosure according to another viewpoint is
Refrigerant piping that constitutes the refrigerant circuit of the refrigeration system.
Equipped with a first pipe and a second pipe,
The first pipe has a first pipe body made of stainless steel and a first connection part provided at an end portion of the first pipe body in the pipe axial direction and made of a material different from stainless steel.
The second pipe has a second pipe body made of stainless steel and a second connection part provided at an end portion of the second pipe body in the pipe axial direction and made of the same material as the first connection part.
The first connection portion and the second connection portion are connected,
Both the first connection portion and the second connection portion are pipes.
The first connection portion, the first pipe main body, the second connection portion, and the second pipe main body are arranged so as to overlap in the pipe radial direction .

(2) The refrigerant piping of the present disclosure is
Refrigerant piping that constitutes the refrigerant circuit of the refrigeration system.
Equipped with a first pipe and a second pipe,
The first pipe has a first pipe body made of stainless steel and a first connection part provided at an end portion of the first pipe body in the pipe axial direction and made of a material different from stainless steel.
The second pipe is provided with a second pipe body made of stainless steel and a second connection part made of the same material as the first connection part, which is provided at the end portion of the second pipe body in the pipe axis direction. Have,
The first connection portion and the second connection portion are connected ,
At least one of the first connection and the second connection is a pipe.
The one connecting portion and the one piping main body provided with the one connecting portion are connected by a first brazing material.
The one connecting portion and the other connecting portion are connected by a second brazing material.
Wherein the first brazing material, that have a higher melting point than the second brazing material.
In addition, the refrigerant piping of the present disclosure according to another viewpoint is
Refrigerant piping that constitutes the refrigerant circuit of the refrigeration system.
Equipped with a first pipe and a second pipe,
The first pipe has a first pipe body made of stainless steel and a first connection part provided at an end portion of the first pipe body in the pipe axial direction and made of a material different from stainless steel.
The second pipe is provided with a second pipe body made of stainless steel and a second connection part made of the same material as the first connection part, which is provided at the end portion of the second pipe body in the pipe axis direction. Have,
The first connection portion and the second connection portion are connected,
Both the first connection portion and the second connection portion are pipes.
The first connection portion, the first pipe main body, the second connection portion, and the second pipe main body are arranged so as to overlap in the pipe radial direction .

(8) is preferably a one connecting part is a tube of the first connecting portion and the second connecting portion, the other connection portion is plated layer.

Claims (15)

A refrigerant pipe that constitutes the refrigerant circuit (4) of the refrigerating device (1).
A first pipe (21) and a second pipe (22) are provided.
The first pipe (21) is provided at the end of the first pipe body (21a) made of stainless steel in the pipe axial direction and is made of a material different from stainless steel. Has a part (21b) and
The second pipe (22) is provided at the end of the second pipe body (22a) made of stainless steel in the pipe axial direction and is the same as the first connection part (21b). It has a second connection (22b) made of material and
A refrigerant pipe to which the first connection portion (21b) and the second connection portion (22b) are connected. A refrigerant pipe that constitutes the refrigerant circuit (4) of the refrigerating device (1).
A first pipe (21) and a second pipe (22) are provided.
The first pipe (21) is provided at the end of the first pipe body (21a) made of stainless steel in the pipe axial direction and is made of a material different from stainless steel. Has a part (21b) and
The second pipe (22) is provided at the end of the second pipe main body (22a) made of stainless steel and the second pipe main body (22a) in the pipe axial direction, and is mainly connected to the first connection portion (21b). It has a second connection (22b) made of the same material and has.
A refrigerant pipe to which the first connection portion (21b) and the second connection portion (22b) are connected. The refrigerant pipe according to claim 2, wherein the first connecting portion (21b) and the second connecting portion (22b) are made of different materials having the same main component. The invention according to any one of claims 1 to 3, wherein each of the first connecting portion (21b) and the second connecting portion (22b) is made of any one of copper, a copper alloy, aluminum, or an aluminum alloy. Coolant piping. Any one of claims 1 to 4, wherein the end of the first pipe body (21a) and the end of the second pipe body (22a) are arranged so as to overlap in the pipe radial direction. Refrigerant piping described in. The first connection portion (21b) is a plating layer applied to the end portion of the first piping main body (21a) or a pipe attached to the end portion of the first piping main body (21a). , The refrigerant pipe according to any one of claims 1 to 5. The second connecting portion (22b) is a plating layer applied to the end portion of the second piping main body (22a) or a pipe attached to the end portion of the second piping main body (22a). , The refrigerant pipe according to any one of claims 1 to 6. One connection portion of the first connection portion (21b) and the second connection portion (22b) is a pipe, and the other connection portion is a plating layer.
The one connecting portion and the one piping main body provided with the one connecting portion are connected by a first brazing material (B1).
The one connecting portion and the other connecting portion are connected by a second brazing material (B2).
The refrigerant pipe according to claim 7, wherein the first brazing material (B1) has a melting point higher than that of the second brazing material (B2). A large diameter portion (22a2) having a diameter larger than that of the other portion of the piping body is provided at the end of the first piping body (21a) or the second piping body (22a).
The refrigerant pipe according to any one of claims 1 to 8, wherein the first connecting portion (21b) or the second connecting portion (22b) is provided on the inner peripheral surface of the large diameter portion (22a2). At the end of the first piping body (21a) or the second piping body (22a), a small diameter portion (21a1) having a diameter smaller than that of other parts of the piping body is provided.
The refrigerant pipe according to any one of claims 1 to 9, wherein the first connecting portion (21b) or the second connecting portion (22b) is provided on the outer peripheral surface of the small diameter portion (21a1). One of the first pipe (21) and the second pipe (22) constitutes a joint for connecting the other pipe and the other stainless steel pipe (23). The refrigerant pipe according to any one of 10. The refrigerant according to any one of claims 1 to 11, wherein at least one of the first pipe (21) and the second pipe (22) is provided in the element component (X) constituting the refrigerant circuit. Plumbing. The outer peripheral surface of at least one of the first pipe body (21a) and the second pipe body (22a) is made of a material having the same main component as the first connection portion (21b) and the second connection portion (22b). A joint pipe (31) made of the same material is attached, and another pipe (32) made of the same material as the joint pipe (31) is connected to the joint pipe (31). The refrigerant pipe according to any one of the above items. The refrigerating device (1) includes a switching mechanism (17) for switching the flow path of the refrigerant in the refrigerant circuit (4).
The refrigerant pipe according to any one of claims 1 to 10, wherein the first pipe main body (21a) or the second pipe main body (22a) is connected to the switching mechanism (17). The refrigerant pipe (10A) according to any one of claims 1 to 14 and
A refrigerating apparatus comprising a refrigerant circuit (4) and an element component (X) to which the refrigerant pipe (10A) is connected.

Images