JP2003074769A - Pipe fitting structure - Google Patents

Abstract

(57) [Summary] [PROBLEMS] The connection work is easy without providing a separate part, and without the need for flaring or the like at the connection end of the refrigerant pipe.
Provided is a pipe joint structure in which the connection state is reliable. SOLUTION: A connection port 31g of a cylindrical connection port main body 31 is provided.
To the straight connection end 2 of the pipe 2 to be connected
b, and a flare nut 5 is screwed into the outer periphery of the flare nut 5 from the connection pipe 2 side to the connection port main body 31 side via a bite type sleeve 32 for retaining. In a pipe joint in which the bite-type sleeve 32 is bitten into the connection pipe 2 by a tightening force, and is connected and fixed to each other, the bite-type sleeve 32 is connected to the connection port 31 side connection port 31.
As a part of the outer peripheral wall of the fitting portion g, it is provided integrally with the distal end side, thereby eliminating a separate part and facilitating the connection work.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to the structure of a joint portion of a pipe joint.

[0002]

2. Description of the Related Art A fluid pipe through which a fluid flows is required to be connected to each other or to a tubular connection port of a fluid supply source side, depending on the pipe state and the pipe position. Therefore, various pipe joints have been conventionally used according to the application.

Among them, for example, refrigerant pipes (liquid pipes, gas pipes) 2 and 2 for interconnecting an indoor unit 1A and an outdoor unit 1B of an air conditioner 1 as shown in FIG. 3, an indoor unit 1A and an outdoor unit 1B. A flare pipe joint structure as shown in FIG. 4 is generally employed for connection with each side connection port (first conventional example).

This flare pipe joint is formed, for example, on a cylindrical connection port body 31 on the side of the union pipe joint 3 (or a connection port body 41 on the side of the closing valve 4) which is fixed to the indoor unit 1A side. Flare corner flare end butt end 3
By abutting the connection end portion of the refrigerant pipe 2 having the flare portion 2a processed into a flare shape corresponding to the flare angle with 1b, and by tightening the outer periphery with the flare nut 5 in the butted state, It is designed to be connected and fixed to each other.

The flare nut 5 is provided with a threaded portion 51a on the inner circumference thereof, which is screwed into a threaded portion 31a formed on the outer circumference of the connection port body 31 on the side of the union fitting 3. -Shaped flare nut main body (threaded cylinder portion) 51 and the flare portion 2a in the abutting state by the taper surface corresponding to the flare angle on the front end portion 53 side of the flare nut main body 51 in the abutting direction. And a crimping cylinder 52 having a diameter smaller than that of the flare nut main body 51 that is pressure-bonded and superposed. The flare nut 5 is used for the refrigerant pipe 2
Before the flaring process is performed on the connection end portion of, the fitting end is fitted and placed on the outer circumference of the refrigerant pipe 2.

The flare portion 2a of the refrigerant pipe 2 is
At the time of connection work at the site, for example, using a flare processing tool having a flare die, the flared portion has a predetermined divergence angle, the width of the flared portion is uniform in the entire circumferential direction, and the inner peripheral surface is a surface. It is carefully processed so that it is in one state.

However, in the case of the flare pipe joint as the first conventional example, considerable processing accuracy is required for flare processing of the connection end of the refrigerant pipe 2 as described above. Have a great impact on sex.

Therefore, at least the above three conditions
In general, careful work is done to ensure that, but it is still a busy work at the installation site,
In addition, there is a problem that a high processing accuracy cannot always be expected due to variations due to the degree of skill of each operator and individual differences.

Therefore, instead of the flare pipe joint as shown in FIG. 4, as shown in FIG. 5, for example, a bite type sleeve (a kind of compression ring) 6 as a separate and independent connecting part is used, and its front end is used. 6a is pressed forward by the rotation of the flare nut 5 in the axial direction, and the connection end portion 2b between the connection port body 31 and the refrigerant pipe 2 on the side of the union pipe joint 3 is pressed.
By facing the mutually straight mating part with and biting, thereby realizing the retaining function and the sealing function, while eliminating the flare processing as described above, the bonding property and the sealing property are further improved. There is one (second conventional example).

That is, reference numeral 31e in FIG. 5 indicates a straight fitting end 2b of the refrigerant pipe 2 provided on the inner peripheral surface on the rear end (connecting end) side of the connecting port body 31. The connecting port portion 31f, which forms a peripheral wall of the connecting port portion 31e, is fitted to the outer peripheral side of the connecting end portion 2b of the refrigerant pipe 2 to crimp the flare nut 5. The front end (biting end) 6a of the biting sleeve 6 pressed forward by the front end 53 of the cylinder 52.
Is a guide portion having a taper surface in the diameter reducing direction for guiding so as to bite into the surface side of the connection end portion 2b of the refrigerant pipe 2.

On the other hand, the rear end 6 of the bite-type sleeve 6
Reference numeral b denotes a tapered surface corresponding to the tapered pressing surface of the front end portion 53 of the crimping cylinder 52 of the flare nut 5, which effectively exerts an appropriate pressing force forward in the axial direction by the rotation of the flare nut 5. I am supposed to receive it.

Further, in the structure shown in FIG. 5 which does not require flare processing, the bite type sleeve 6 of the 1-compression ring system is replaced with the front ferrule (first compression ring) 8 on the front side. A two-compression-ring type pipe joint as shown in FIG. 6 is also provided in which two compression rings of the back ferrule (second compression ring) 9 are provided on the rear side to more reliably realize the retaining function and the sealing function. (Third conventional example).

According to the two-compression ring type pipe joint shown in FIG. 6, the front end 8a and the rear end 8b of the front ferrule 8 and the front end 9a and the rear end 9b of the back ferrule 9 cooperate with each other. While effectively preventing the disconnection, the connection port body 31 and the crimping cylinder 52 of the flare nut 5 are provided.
Since the space between and is reliably sealed, the coupling performance and the sealing performance are further improved.

[0014]

However, in the cases of the above-mentioned second and third conventional examples, the bite-in type sleeve and each ferrule are independent small parts in any of them, and the number of parts is large. At the same time, there is a problem that it takes time to work by dropping or eliminating them during connection work.

The present invention has been made in order to solve such a problem, and in the fitting state of the mating connection port portion and the pipe to be connected to the connection port portion, a bite type sleeve is provided at the outer periphery thereof. In a pipe joint configured to be connected and fixed to each other by tightening with a flare nut, by providing the bite-type sleeve as a part of the mating connection port portion, problems such as increase or loss of the number of parts described above are caused. It is an object of the present invention to provide a structure of a pipe joint that has been resolved.

[0016]

In order to achieve the above object, the present invention comprises the following means for solving problems.

(1) Invention of Claim 1 In the structure of the pipe joint of the present invention, the straight connecting end portion 2b of the pipe 2 to be connected is inserted into the connecting port portion 31g of the tubular connecting port body 31. While fitting, on the outer periphery,
The flare nut 5 from the side of the connection pipe 2 to the side of the connection port main body 31 through the bite-in type sleeve 32 for preventing slipping out.
In which the bite-type sleeve 32 is bited into the connection pipe 2 by the tightening force of the flare nut 5 to mutually connect and fix the
The bite-type sleeve 32 is integrally provided on the tip end side as a part of the outer peripheral wall of the fitting portion of the connection opening body 31 side connection opening portion 31g.

That is, in the structure of the present invention, first, the straight connection end portion 2b of the pipe 2 to be connected is connected to the connection port portion 31g for pipe fitting of the mating tubular connection port body 31.
In the same fitted state, a flare nut 5 is fitted to the outer periphery of the flare nut 5 through a retaining bite sleeve 32 for preventing the flare nut 5 from the connection pipe 2 side to the connection port. The bite-type sleeve 32 is made to bite into the connection pipe 2 by screwing and tightening on the main body 31 side, and the connection port body 31 of the connection pipe 2
Make sure to securely connect and fix the fitting part to the seal.

Accordingly, when the screwing of the flare nut 5 into the connection port body 31 is completed, the tip of the bite-type sleeve 32 bites into the connection pipe 2 to surely realize the retaining function and the sealing function. Secure connection is maintained.

(2) Invention of Claim 2 In the structure of the pipe joint of the present invention, in the structure of the invention of claim 1, the bite-type sleeve 32 is gradually moved from the tip end 32a side toward the base end 32b side. It is characterized by a large thickness.

Therefore, as the flare nut 5 is screwed from the side of the connection pipe 2 to the side of the connection port main body 31, a gradually larger tightening force (caulking force) acts on the bite type sleeve 32. Becomes,
As a result, a smooth and effective biting action on the connecting pipe 2 side is realized.

(3) Invention of Claim 3 In the structure of the pipe joint of this invention, in the structure of the invention of claim 1 or 2, the inner periphery of the flare nut 5 is
When screwed into the connection port body 31 side, the tip 32a of the bite-type sleeve 32 is securely connected to the connection pipe 2
It is characterized in that crimping portions 54a and 54b are provided so as to bite into the side.

Therefore, when the flare nut 5 is screwed from the connection pipe 2 side to the connection port main body 31 side, the bite-type sleeve 32 has the crimp portion 5 attached thereto.
A large tightening force is applied to the 4a and 54b, whereby a smooth and effective biting action to the side of the connecting pipe 2 is realized.

(4) Invention of claim 4 In the structure of the pipe joint of this invention, in the structure of the invention of claim 1, 2 or 3, the pipe 2 to be connected is a refrigerant for refrigeration systems 1A, 1B. The refrigerant is a pipe, and the refrigerant flowing through the refrigerant pipe is a new refrigerant R32 or a mixed refrigerant containing 70% or more by weight of the new refrigerant R32.

Although it is expected that such a refrigerant for the refrigerating apparatuses 1A and 1B will become widespread in the future, since it is a flammable refrigerant, it is particularly required to have a high sealing property of the above-mentioned connecting portion and a difficulty in coming off. It

Therefore, the structure of the invention of claim 1, claim 2 or claim 3 is particularly suitable for the connection of the refrigerant pipe for the refrigerating apparatus using the flammable refrigerant, and the sealing performance of the connection portion and the reliability of the connection state. It is possible to secure the sex.

(5) Invention of Claim 5 In the structure of the pipe joint of this invention, in the structure of the invention of Claims 1, 2 or 3, the pipe 2 to be connected is a refrigerant for refrigeration systems 1A, 1B. The refrigerant flowing through the refrigerant pipe is a flammable gas or a toxic gas defined in Article 2 of the Refrigeration Safety Regulations based on the High Pressure Gas Safety Act.

Although the refrigerants for the refrigerating apparatuses 1A and 1B as described above have already been used, they are flammable or toxic, so that particularly reliable sealing and fixing of the above-mentioned connecting portion are required.

Therefore, the configuration of the invention of claim 1, 2 or 3 is particularly suitable for connecting a refrigerant pipe for a refrigerating apparatus using the flammable or toxic gas refrigerant, and the sealing performance of the connecting portion and The reliability of the connection state can be secured.

(6) Invention of claim 6 In the structure of the pipe joint of this invention, in the structure of the invention of claim 1, 2 or 3, the pipe 2 to be connected is a refrigerant for the refrigeration systems 1A, 1B. The refrigerant is a pipe, and the refrigerant flowing through the refrigerant pipe is a carbon dioxide refrigerant.

Such a refrigerant for the refrigerating apparatuses 1A and 1B is expected to become more widespread as an alternative refrigerant in the future, but it also has a problem of global warming and its emission is regulated. It is required to have high sealing performance and to be hard to come off.

Therefore, the structure of the invention of claim 1, 2 or 3 is particularly suitable for connection of the refrigerant pipe for the refrigerating apparatus using the carbon dioxide refrigerant, and the sealing performance of the connection portion and the reliability of the connection state. It is possible to secure the sex.

[0033]

As a result of the above, according to the structure of the pipe joint of the present invention, the following beneficial effects can be obtained.

Since the bite-type sleeve that is the connecting member is integrated on the side of the connection port that is the main body, the number of parts does not increase unlike the case of separate parts as in the past, and can be dropped during connection work. , There is no fear of losing it, and connection work becomes easier.

It is possible to secure more reliable connection performance and sealing performance without requiring processing such as flare processing on the pipe side to be connected.

After the connection is completed, the connected state is surely kept regardless of the flare nut, and the deterioration of the sealing property due to a continuous element such as loosening of the flare nut is less likely to occur.

Once connected, it cannot be easily removed after that, so it is possible to surely eliminate the possibility that the refrigerant will leak accidentally during maintenance work or the like.

Since it is possible to surely achieve the high sealing performance of the connection portion and the maintenance and securing of the high sealing performance thereof, it is particularly advantageous when using a refrigerant or the like that is highly regulated in an air conditioner or other refrigeration system. Becomes

[0039]

1 and 2 show a structure of a pipe joint according to an embodiment of the present invention, which is applied to a connection of a refrigerant pipe of an air conditioner which is an example of a refrigerating apparatus.

The pipe joint of the present embodiment has the configuration shown in FIG.
Although it is based on the structure of a pipe joint that does not require flare processing as shown in Fig. 6, it reduces the number of parts to facilitate connection work at the time of connection and also ensures a connected state with sealing property after connection. In order to maintain it, it is characterized in that a bite-type sleeve for connection is integrally provided on the connection port side of the connection port body.

In such a structure, after the flare nut is completely screwed, the biting force of the bite type sleeve integrated with the connection port body side ensures that the connected state is reliably maintained regardless of the flare nut. Therefore, even if the flare nut is removed, the connection of the refrigerant pipe to the connection port body is not disconnected, and the reliable connection state can be maintained.

That is, the pipe joint of this embodiment is, for example, the inner peripheral side refrigerant pipe of the cylindrical connection port body (union collar) 31 of the union pipe joint 3 fixed to the indoor unit 1A side in FIG. The straight connection end 2b of the refrigerant pipe 2 having no flare portion is inserted and fitted into the connection port portion 31g having the fitting groove portion, and the flare nut is provided on the outer periphery of the flare nut via the biting sleeve 32 described later. By screwing 5 together and tightening, it is possible to securely connect and fix.

The flare nut 5 is a concentric socket with different diameters as shown in the drawing, and has a threaded portion 51a on its inner peripheral surface side as shown in the drawing, and has a connection port on the side of the union fitting 3. A tubular flare nut body 51 screwed into a threaded portion (union screw) 31a formed corresponding to the outer peripheral surface side of the body (union collar) 31, and the flare nut body 5
It is composed of a relatively small diameter crimping cylinder 52 having a crimping portion 54 on the inner peripheral surface side of the inner front end portion 52a of the crimping portion 52 which is located rearward of the first crimping cylinder 52. The flare nut 5 and the bite-type sleeve 32 to be described later are fitted to the refrigerant pipe 2 at a stage before fitting the connection end portion 2a of the refrigerant pipe 2 to the connection opening portion 31g of the connection body 31. Put.

On the other hand, reference numeral 32 is a bite-type sleeve which is integrally provided with the outer peripheral wall of the rear end side connection port portion 31g of the connection port body 31 and extends rearward by a predetermined dimension. In a state where the main body 31 is completely screwed, the tip 32a of the main body 31 is made to bite into the outer peripheral surface of the connection pipe 2. As a result, the connection end portion 2b of the refrigerant pipe 2 and the connection port main body 31 are surely connected to each other, and a press-contact state with a high sealing property between the fitting surfaces of the connection port portion 31g is secured. The connection state cannot be easily removed to prevent accidental removal.

On the other hand, the bite-type sleeve 32 has an inner peripheral surface of equal diameter slidably fitted to the outer periphery of the straight connecting end portion 2b of the refrigerant pipe 2, as shown in the figure. The wall thickness of the peripheral wall portion is gradually increased so that the outer peripheral surface of the sleeve main body is made of a tubular brass as a whole, and the outer peripheral surface of the sleeve main body gradually rises in the direction of the base end side 32b. It is enlarged and is continuous with the threaded portion 31a of the connection port body 31.

On the other hand, the crimping portion 54 inside the front end portion 52a of the flare nut 5 side crimping cylinder 52 is in a press-fit state in which the tightening force gradually increases from the tip end 32a side of the bite type sleeve 32 to the vicinity of the base end side 32b. At least the biteable sleeve 32 so that they can be fitted together.
Has a recessed groove portion (circumferential recessed groove portion) having an inner diameter slightly larger than the outer diameter of the tip end 32a, and the first crimping edge 54a for fitting the bite-type sleeve at the front end in the screwing direction and the rear in the same screwing direction 2nd for crimping the bite sleeve on the end
Two crimping edges having different inner diameters from the crimping edge 54b are provided.

Therefore, in this configuration, the connection port body 3 in which the connection end portion 2b of the refrigerant pipe 2 into which the flare nut 5 is fitted is integrated with the bite type sleeve 32 as described above.
1 is inserted into the rear end side connection port portion 31g and fitted as shown in FIG. 1, and then the flare nut 5 is further rotated and screwed into the threaded portion 31a of the connection port body 31. When you go
The crimp portion 54 of the flare nut 5 is fitted into the bite-type sleeve 32, and in the course of approaching the state of FIG.
The first crimping edge 54a on the front end side of the crimping portion 54 of the flare nut 5 is the base end side 32 of the bite-type sleeve 32.
Ride up to near b and tighten to securely connect the sleeve body of the bite-in type sleeve 32 to the piping 2 (connection end 2
Adhere closely to the outer peripheral surface of b).

Then, when the flare nut 5 is further screwed to the connection port body 31 and the state immediately before the screwing is completed as shown in FIG. 2, the rear end side second crimping edge 54b of the crimping portion 54 is removed. The tip 32a having an acute-angled cross section of the bite-type sleeve 32 is narrowed down in the direction of the central axis from the direction of 360 [deg.] To surely bite the connection end 2b of the already-fitted refrigerant pipe 2 from the outer peripheral surface side to the inner side. The engaging portion 2c is formed by firmly connecting and locking the same connection state so that it cannot be easily removed.

As described above, the structure of the pipe joint of the present invention is such that the connection port portion 31g of the tubular connection port body 31 is
The straight connecting end 2b of the pipe 2 to be connected is inserted and fitted, and the flare nut is connected from the side of the connecting pipe 2 to the side of the connecting port main body 31 through the bite-type sleeve 32 for retaining the outer periphery thereof. 5 are screwed together, and the flare nut 5 is tightened by the tightening force of the flare nut 5.
In the pipe joint configured to bite into the connection pipe 2 to be connected and fixed to each other, the bite-type sleeve 32 is a part of a fitting portion outer peripheral wall of the connection port body 31 side connection port portion 31g, It is characterized in that it is integrally provided on the tip side.

That is, in the structure of the present invention, first, the straight connection end portion 2b of the pipe 2 to be connected is connected to the connection port portion 31g of the mating tubular connection port body 31 for fitting the pipe.
In the same fitted state, the flare nut 5 is fitted to the outer periphery of the flare nut 5 through the bite-in type sleeve 32 for preventing slippage, and the flare nut 5 is connected to the connecting pipe 2
Side to the connection port main body 31 side by tightening by screwing the bite type sleeve 32 into the connection pipe 2
And the fitting portion of the connection pipe 2 to the connection port main body 31 is reliably sealed and securely connected and fixed.

Therefore, when the flare nut 5 is screwed into the connection port body 31, the tip of the bite-type sleeve 32 bites into the connection pipe 2 to surely realize the retaining function and the sealing function. Secure connection is maintained.

Further, in the structure of the pipe joint of the present invention, the bite-in type sleeve 32 is characterized in that the thickness gradually increases from the tip end 32a side toward the base end 32b side.

Therefore, as the flare nut 5 is screwed from the connection pipe 2 side to the connection port body 31 side, a gradually larger tightening force (caulking force) acts on the bite type sleeve 32. Becomes,
As a result, a smooth and effective biting action on the connecting pipe 2 side is realized.

Further, in the structure of the pipe joint of the present invention, the tip 32a of the bite-type sleeve 32 is securely connected to the inner periphery of the flare nut 5 when it is screwed into the connection port body 31 side. Crimping part 54 that bites into the 2 side
It is characterized in that a and 54b are provided.

Therefore, when the flare nut 5 is screwed from the connection pipe 2 side to the connection port main body 31 side, the bite-type sleeve 32 has the same crimp portion 5 attached thereto.
A large tightening force is applied to the 4a and 54b, whereby a smooth and effective biting action to the side of the connecting pipe 2 is realized.

As a result of the above, according to the structure of the pipe joint of the present invention, the following beneficial effects can be obtained.

Since the bite-type sleeve that is the connecting member is integrated on the side of the connection port that is the main body, the number of parts does not increase unlike the case of separate parts as in the past, and can be dropped during connection work. , There is no fear of losing it, and connection work becomes easier.

It is possible to secure more reliable connection performance and sealing performance without requiring processing such as flare processing on the pipe side to be connected.

After the connection is completed, the connected state is surely kept regardless of the flare nut, and the deterioration of the sealing property due to a continuous element such as loosening of the flare nut is less likely to occur.

Once the connection is made, it cannot be easily removed after that, so that it is possible to surely eliminate the possibility that the refrigerant will be erroneously leaked during maintenance work or the like.

Since it is possible to surely realize the high sealing performance of the connection portion and the maintenance and securing of the high sealing performance, it is particularly advantageous when using a refrigerant or the like that is highly regulated in an air conditioner or other refrigeration equipment. Becomes

In the above description, the case where the refrigerant pipe 2 is connected to the connection port main body 31 of the union pipe joint 3 on the indoor unit 1A side in FIG. 3 has been described. Needless to say, the same can be applied to the case of connecting with the connection port body 41 of the outdoor unit 1B side closing valve (three-way valve) 4 of FIG.

(Modifications) (1) The structure of the pipe joint of the present invention is not limited to the refrigerant pipe for the refrigerating apparatus as described above, but can be applied to various applications. As in the case of the refrigeration apparatus of each embodiment, the pipe 2 to be connected is a refrigerant pipe, and the refrigerant flowing through the refrigerant pipe contains, for example, 70% or more by weight of the new refrigerant R32 or the new refrigerant R32. It is effective when it is a flammable refrigerant such as a mixed refrigerant.

The refrigerant other than R32 may be a fluorinated refrigerant or a natural refrigerant. Natural refrigerants include
It includes propane, butane, CO ₂ , ammonia and the like.
As such a mixed refrigerant, for example, R32 is 70 to 9
0 wt. %, With the balance being CO ₂ . In addition, so-called retrofit or R, which fills R32 as an alternative refrigerant into an old type refrigeration system,
As a mixed refrigerant, R32
70-90 wt. %, And the remaining component is R22 can also be used.

It is expected that such a refrigerant for a refrigerating apparatus will be widely used in the future, but since it is flammable, it is particularly required to have a high sealing property of the above-mentioned connecting portion and a difficulty in coming off.

Therefore, the structure of the pipe joint of the invention of the present application is particularly suitable for connection of the refrigerant pipe for the refrigerating apparatus using the refrigerant, and the sealing performance of the connecting portion and the reliability of the connected state are ensured. You can

(2) The structure of the pipe joint of the present invention is not limited to the refrigerant pipe for the refrigerating apparatus as described above, but can be applied to various uses, but in particular, each of the embodiments described above is applicable. , The refrigerant to be connected is a refrigerant pipe, and the refrigerant flowing through the refrigerant pipe is defined in Article 2 of the Refrigeration Safety Regulations, which is defined based on the High Pressure Gas Safety Act, for example. It is effective when the refrigerant is a flammable gas (for example, ammonia, isobutane, ethane, ethylene, chloromethyl, normal butane and propane) or a toxic gas (for example, ammonia and chloromethyl).

Although the refrigerant for such a refrigerating apparatus has already been used, it is flammable or toxic, so that particularly reliable sealing and fixing of the above-mentioned connecting portion are required.

Therefore, the structure of the pipe joint of the present invention is particularly suitable for the connection of the refrigerant pipe for the refrigeration system using the refrigerant, and the sealing performance of the connecting portion and the reliability of the connected state are ensured. You can

(3) The structure of the pipe joint of the present invention is not limited to the refrigerant pipe for the refrigerating apparatus as described above, but can be applied to various applications, but in particular, each of the embodiments described above is applicable. This is effective when the pipe 2 to be connected is a refrigerant pipe and the refrigerant flowing through the refrigerant pipe is, for example, a carbon dioxide refrigerant (CO ₂ refrigerant), as in the case of the refrigerating machine.

It is expected that such a refrigerant for a refrigeration system will become more popular in the future, but since it also has a problem of global warming and its emission is regulated, a reliable sealing property of the above-mentioned connection portion is particularly required. Fixedness is required.

Therefore, the structure of the pipe joint of the present invention is particularly suitable for connecting the refrigerant pipe for the refrigerating apparatus using the carbon dioxide refrigerant, and secures the sealing performance of the connecting portion and the reliability of the connected state. can do.

(4) The refrigerating apparatus to which the invention of the present application is applied is not limited to the case of the air conditioner as described above, but can be applied to the refrigerating apparatus and other various refrigerating apparatuses in the same manner. Needless to say.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a pipe joint according to a first embodiment of the present invention at the start of connection.

FIG. 2 is a cross-sectional view showing the structure of the pipe joint, just before the end of connection.

FIG. 3 is a schematic diagram showing a connection state of refrigerant pipes between an indoor unit and an outdoor unit of a conventional general air conditioner.

FIG. 4 is a cross-sectional view showing a structure of a pipe joint according to a first conventional example.

FIG. 5 is a cross-sectional view showing a structure of a pipe joint according to a second conventional example.

FIG. 6 is a cross-sectional view showing a structure of a pipe joint according to a third conventional example.

[Explanation of symbols]

1 is an air conditioner, 1A is an indoor unit, 1B is an outdoor unit, 2 is a refrigerant pipe, 2a is a flare portion, 2b is a connecting end portion, 3 is a union pipe joint, 4 is a closing valve, 5 is a flare nut, and 31 is Connection port body, 31a is a threaded portion, 31g is a connection port portion, 51 is a flare nut body, 52 is a crimping cylinder, 52a
Is a front end portion, 54 is a crimping portion, 54a is a first crimping edge,
54b is a second crimping edge.

Claims (6)

[Claims] 1. A straight connection end portion (2b) of a pipe (2) to be connected is inserted into and fitted into a connection opening portion (31g) of a tubular connection opening body (31), and its outer circumference. Then, through the bite-in type sleeve (32) for retaining, from the side of the connection pipe (2) to the connection port body (31).
A flare nut (5) is screwed to the side, and the bite type sleeve (32) is bited into the connection pipe (2) by the tightening force of the flare nut (5) to connect and fix them to each other. In the pipe joint, the bite type sleeve (32) is integrally provided on the tip side as a part of the outer peripheral wall of the fitting portion of the connection opening body (31) side connection opening (31g). The structure of the pipe joint characterized by the fact that 2. The bite type sleeve (32) according to claim 1, wherein the bite type sleeve (32) has a thickness that gradually increases from the tip end (32a) side toward the base end (32b) side. Construction. 3. The inner periphery of the flare nut (5) is adapted to bite the tip (32a) of the bite-type sleeve (32) into the connection pipe (2) side when screwed into the connection port body (31). The structure of the pipe joint according to claim 1 or 2, wherein crimping portions (54a), (54b) are provided. 4. The piping (2) to be connected is a refrigeration system (1).
The refrigerant pipes for A) and (1B), wherein the refrigerant flowing through the refrigerant pipe is a new refrigerant R32 or a mixed refrigerant containing 70% or more by weight of the new refrigerant R32. The structure of the pipe joint according to 2 or 3. 5. The refrigerating device (1) is provided with a pipe (2) to be connected.
Refrigerant piping for A) and (1B), and the refrigerant flowing through the refrigerant piping is a flammable gas or a toxic gas defined in Article 2 of the Refrigeration and Safety Regulations based on the High Pressure Gas Safety Act. The structure of the pipe joint according to claim 1, 2, or 3. 6. The refrigerating device (1) is provided with piping (2) to be connected.
4. The pipe joint structure according to claim 1, wherein the refrigerant pipe is for A) and (1B), and the refrigerant flowing through the refrigerant pipe is carbon dioxide refrigerant.