JPWO2020174517A1 - Refrigerant pipe joint structure - Google Patents

Abstract

The purpose is to improve the productivity of flare nuts provided with drain holes and to obtain a refrigerant pipe joint structure that keeps costs down while maintaining reliability against refrigerant leakage. The present invention includes a copper pipe having a pipe portion and a flare portion in which the end portion of the pipe portion is expanded in a tapered shape, and a union formed in a tapered shape at the tip portion and having a refrigerant flow path on a central axis. , A flare nut with a female thread that screwed into the union. The flare nut has a through hole through which the pipe portion of the copper pipe is passed, a relief shape formed at the end of the female thread portion, and a tapered flare sheet surface formed between the relief shape and the through hole. , It is provided with a communication hole for communicating the relief shape and the external space. The union has a tapered seat surface at the tip and a male screw portion formed on the side surface, and is screwed and fastened to the female screw portion. The flare portion of the copper tube is the flare seat surface and the union sheet. It is sandwiched between the surfaces and the communication hole is open to the end surface on which the female threaded portion is formed, and the central axis of the communication hole is parallel to the central axis of the female threaded portion.

Description

The present invention relates to a refrigerant pipe joint structure of a refrigeration cycle device, and more particularly to a drainage hole provided in the refrigerant pipe joint structure.

In a refrigeration cycle device such as a split type air conditioner, a flare joint is used to connect the indoor / outdoor connection pipe connecting the indoor unit and the outdoor unit to the indoor unit and the outdoor unit. In recent years, as a refrigerant for air conditioners, a combustible refrigerant such as R32 has been used as a measure against global warming. If such a combustible refrigerant leaks and stays in a closed space, it may be mixed with air to reach a concentration at which the refrigerant burns. Therefore, in order to reduce the refrigerant leakage, a joint having high reliability against the refrigerant leakage is required.

The flared joint is sealed by sandwiching the flared copper tube between the union and the seat surface of the flared nut. As a result, the structure is such that the refrigerant flowing in the copper pipe is sealed so as not to leak to the outside. The flare nut and the union are fastened with screws and tightened to a predetermined torque. The seal structure is formed by completely adhering the seat surface of the flare nut and the seat surface of the union to the flare portion of the copper tube (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-155726

In the pipe joint structure of Patent Document 1, when the screw is tightened, the flare portion of the copper pipe is compressed between the union and the seat surface of the flare nut, so that the flare portion of the copper pipe is when the screw is tightened. It is compressed and thinned by the axial force, and stretches toward the tip of the flared portion of the copper tube. Therefore, the flare nut is configured so that it does not come into contact with the inner peripheral surface of the flare nut even if the tip of the flare portion is stretched. When the contact area between the flare portion of the copper tube and the seat surface of the union and the flare nut is large in order to improve the sealing property, the flare nut is provided with a space for allowing the tip of the flare portion to be extended to escape.

The temperature of the flare joint may decrease due to the operation of the air conditioner. At this time, dew condensation water may be generated in the flare joint portion, and the dew condensation water may collect in the space where the tip of the flare portion provided in the flare nut escapes. Further, when the temperature of the flare joint portion drops below the freezing point, the accumulated water freezes and expands, and the tip of the flare portion of the copper tube is pushed by the expanded ice. When the dew condensation water freezes and melts repeatedly inside the flare nut, the flare portion of the copper tube is finally pushed out from the sheet surface. When the flared portion of the copper pipe is removed from the joint, the sealing property is lost and the refrigerant flowing in the copper pipe is released into the atmosphere. Flammable refrigerant may stay in a closed space and mix with air to a concentration at which the refrigerant burns.

As a countermeasure against this, in the conventional flare nut, a drain hole is provided from the side surface of the flare nut so as to communicate the space where the tip of the flare portion escapes with the external space, and the pressure generated by the expansion of ice due to freezing is released. .. The flare nut is machined by rotating the flare nut or tool around the central axis of the screw. On the other hand, in a flare nut in which a drain hole is provided from the side surface of the flare nut, it is necessary to apply a tool from the side surface of the flare nut to perform drilling. In this case, for example, the process of forming a screw of a flare nut and the process of making a drain hole are performed in different processing processes, so that there is a problem that productivity is lowered.

The present invention is for solving the above-mentioned problems, and an object of the present invention is to obtain a refrigerant pipe joint structure in which the productivity of a flare nut provided with a drain hole is improved.

The refrigerant pipe joint structure according to the present invention has a copper pipe having a pipe portion and a flare portion in which the end portion of the pipe portion is expanded in a tapered shape, and a copper pipe having a tapered tip portion formed on a central axis. A union having a refrigerant flow path and a flare nut having a female threaded portion screwed with the union are provided, and the flare nut includes a through hole through which the pipe portion of the copper pipe is passed and the female threaded portion. A relief shape formed at the end of the screw, a tapered flare sheet surface formed between the relief shape and the through hole, and a communication hole for communicating the relief shape and the external space are provided. The union has a tapered seat surface at the tip and a male screw portion formed on the side surface, and is screwed and fastened to the female screw portion, and the flare portion of the copper tube is the flare sheet. It is sandwiched between the surface and the seat surface of the union, and the communication hole is opened at the end surface on which the female threaded portion is formed, and the central axis of the communication hole is the central axis of the female threaded portion. Is parallel to.

According to the present invention, even if the water accumulated inside the flare nut freezes and expands, the expansion pressure is released from the communication hole to prevent the flare portion of the copper pipe from being pushed out by the frozen ice and falling off. Has. At the same time, by making the direction of processing the communication hole the same as the direction of the central axis for processing the structure such as the screw of the flare nut, the communication hole can be processed in the same processing process. As a result, when processing the flare nut, it is not necessary to provide a separate process for processing the communication hole, and the productivity of the flare nut is improved.

It is an external view of the refrigerant pipe joint structure 100 which concerns on Embodiment 1. FIG. It is sectional drawing explaining the refrigerant pipe joint structure 100 which concerns on Embodiment 1. FIG. 2 is a plan view and a cross-sectional view of the flare nut 1 of FIG. It is sectional drawing of the end part of the copper tube 10 of FIG. It is sectional drawing of the end part of the union 7 of FIG. It is sectional drawing of the structure of the refrigerant pipe joint structure 1000 as a comparative example of the refrigerant pipe joint structure 100 which concerns on Embodiment 1. FIG. It is a top view and the cross-sectional view of the flare nut 1 of the refrigerant pipe joint structure 200 which concerns on Embodiment 2. FIG. It is an enlarged view of the part B of FIG.

An embodiment of the refrigerant pipe joint structure will be described below. The form of the drawings is an example, and does not limit the present invention. In addition, those having the same reference numerals in the respective figures are the same or equivalent thereof, which are common to the entire text of the specification. Further, in the drawings below, the relationship between the sizes of the constituent members may differ from the actual one.

Embodiment 1.
FIG. 1 is an external view of the refrigerant pipe joint structure 100 according to the first embodiment. The refrigerant pipe joint structure 100 according to the first embodiment is used for a refrigeration cycle device such as an air conditioner. For example, in an air conditioner including an outdoor unit and an indoor unit, it is necessary to connect the outdoor unit and the indoor unit and an internal / outdoor connection pipe connecting the outdoor unit and the indoor unit. The refrigerant pipe joint structure 100 shown in FIG. 1 connects the inside / outside connection pipe and the refrigerant pipe of the outdoor unit or the indoor unit. The refrigerant pipe joint structure 100 connects the union 7 provided at the end of the refrigerant pipe of the outdoor unit or the indoor unit, the copper pipe 10 provided at the end of the internal / external connection pipe, and the copper pipe 10 and the union 7. It is composed of a flare nut 1 that seals the refrigerant.

In the split type air conditioner, a flare joint is used to connect the indoor / outdoor connection pipe and the indoor unit that connect the indoor unit and the outdoor unit, and the outdoor unit. In recent years, refrigerants having a small global warming potential (GWP), such as R32 and R290, have come to be used as refrigerants for air conditioners. Since a refrigerant having a small GWP is generally combustible, it may leak into the atmosphere, stay in a closed space, and be mixed with air to have a concentration at which the refrigerant burns. Therefore, the flare joint is required to have higher reliability against refrigerant leakage from the joint than when a non-combustible refrigerant such as R410A is used. The refrigerant pipe joint structure 100 secures the sealing property and suppresses the leakage of the refrigerant by the structure described below.

FIG. 2 is a cross-sectional view illustrating the refrigerant pipe joint structure 100 according to the first embodiment. FIG. 3 is a plan view and a cross-sectional view of the flare nut 1 of FIG. FIG. 4 is a cross-sectional view of the end portion of the copper tube 10 of FIG. FIG. 5 is a cross-sectional view of the end of Union 7 of FIG. In FIG. 2, only the upper half shows the entire cross-sectional structure, and the lower half shows the cross-sectional structure of only the flare nut 1. As shown in FIG. 2, the refrigerant pipe joint structure 100 includes a copper pipe 10 having a flare portion 11 whose end is expanded in a conical surface shape, and a through hole 6 and a flare portion 11 through which the copper pipe 10 is passed. It is composed of a combination of a flare nut 1 having a flare seat surface 2 which is a conical surface with which the two are in contact, and a union 7 having a conical seat surface 8 at the tip end portion.

The copper tube 10 is passed through the through hole 6 of the flare nut 1 and extends toward one end surface 13 of the flare nut 1, and the flare portion 11 is in contact with the flare sheet surface 2 of the flare nut 1. The union 7 is screwed from the other end surface 14 side on which the female screw portion 4 of the flare nut 1 is formed, and the seat surface 8 at the tip is in contact with the flare portion 11 on the flare seat surface 2. By fastening the union 7 and the flare nut 1 with a predetermined torque, the flare portion 11 of the copper tube 10 is compressed between the flare seat surface 2 of the flare nut 1 and the seat surface 8 at the tip of the union 7. .. The flare portion 11 is compressionally deformed between the flare sheet surface 2 and the sheet surface 8 of the union 7, and is brought into close contact with the flare sheet surface 2 and the sheet surface 8 to ensure sealing performance.

As shown in FIG. 3, the flare nut 1 is a main body having a hexagonal outer peripheral surface 15 in a plan view, and a through hole provided in the center of the hexagon from one end surface 13 side, and is a copper tube 10. It is provided with a through hole 6 through which the thread is passed, and a female screw portion 4 provided at the center of the hexagon from the other end surface 14 side. Between the through hole 6 and the female screw portion 4, the tapered flare sheet surface 2 and the relief shape 3 for preventing the tip portion 12 of the flare portion 11 from contacting the inner peripheral surface 16 of the flare nut 1. And are provided. The flare sheet surface 2 is formed from the end of the through hole 6 and is a tapered surface in a direction that expands with respect to the inner diameter dimension of the through hole 6. Furthermore, the flare sheet surface 2 is a conical surface. The relief shape 3 is formed between the flare sheet surface 2 and the female screw portion 4. On the female threaded portion 4 side of the flare sheet surface 2, a cylindrical inner peripheral surface 16 larger than the inner diameter of the end on the enlarged diameter side of the flare sheet surface 2 is formed, and the inner peripheral surface 16 forms a cylindrical inner peripheral surface 16. The tip portion 12 of the flare portion 11 is configured to escape to the formed space. Further, the inner peripheral surface 16 of the relief shape 3 is larger than the inner diameter of the female screw portion 4. Further, a communication hole 5 is formed from the end surface 14 on which the female screw portion 4 of the flare nut 1 is formed toward the relief shape 3. The communication hole 5 opens in the end surface 14 to communicate the external space and the space formed inside the flare nut 1 formed by the relief shape 3.

As shown in FIG. 4, the end portion of the copper tube 10 on the flare nut 1 side has an enlarged diameter to form a flare portion 11 which is enlarged in a tapered shape. As shown in FIG. 5, the union 7 is provided with a refrigerant flow path 17 which is a hole through which the refrigerant flows in the central portion, and the tip portion is formed in a truncated cone shape whose outer diameter decreases toward the tip. ing. A refrigerant flow path 17, which is a hole through which the refrigerant flows, is opened on the truncated cone-shaped end surface at the tip of the union 7. The tapered surface at the tip of the union 7 is the sheet surface 8 that comes into contact with the flare portion 11. That is, the union 7 is provided with a tapered seat surface 8 at the tip end portion. In the first embodiment, the flare sheet surface 2, the sheet surface 8, and the flare portion 11 are formed so as to form an angle of 45 degrees with the central axis in the cross section shown in FIGS. 2 to 5. However, the flare sheet surface 2, the sheet surface 8, and the flare portion 11 are not limited to the conical surface having this angle, and the shape can be appropriately changed as long as it is tapered.

Returning to FIG. 2, the refrigerant pipe joint structure 100 is a flare joint, and the conical flare portion 11 of the copper pipe 10 is sandwiched between the flare seat surface 2 of the flare nut 1 and the seat surface 8 of the union 7. The sealing property is secured by. The female threaded portion 4 of the flare nut 1 and the male threaded portion 9 of the union 7 are screwed together, the flare nut 1 is rotated and tightened with a tool or the like, and the flare portion 11 of the copper tube 10 is compressed by the axial force of the screw. It adheres to the flare seat surface 2 of the flare nut 1 and the seat surface 8 of the union 7. As a result, the refrigerant flowing in the copper pipe 10 is sealed. When the screw is tightened, the flare portion 11 of the copper tube 10 is compressed by the seat surface 8 of the union 7 and the flare seat surface 2 of the flare nut 1, so that the flare portion 11 of the copper tube 10 tends to be slightly thinner. It is deformed and stretches in the direction of the tip portion 12 of the flare portion 11 of the copper tube 10. Since the flare nut 1 is formed with a relief shape 3 for allowing the tip portion 12 of the flare portion 11 of the copper tube 10 to escape, even if the tip portion 12 of the flare portion 11 of the copper tube 10 is stretched, the flare nut 1 It is configured so as not to collide with the inner peripheral surface 16.

The temperature of the refrigerant pipe joint structure 100 may decrease due to the operation of the air conditioner. When the temperature drops, dew condensation water is generated inside the refrigerant pipe joint structure 100, and the dew condensation water may collect in the relief shape 3 for releasing the tip portion 12 of the flare portion 11 of the copper pipe 10. Further, when the temperature of the refrigerant pipe joint structure 100 drops to below the freezing point, the frozen condensed water expands, and the tip portion 12 of the flare portion 11 of the copper pipe 10 is pushed by the expanded ice. Is done. When the condensed water repeatedly freezes and melts inside the refrigerant pipe joint structure 100, the flare portion 11 of the copper pipe 10 is finally pushed out from between the flare seat surface 2 of the flare nut 1 and the seat surface 8 of the union 7. Is done. Then, the flare portion 11 is removed from between the flare sheet surface 2 and the sheet surface 8 to lose the sealing property, and the refrigerant flowing in the copper tube 10 is ejected and released into the atmosphere. At this time, the flammable refrigerant may leak from the refrigerant pipe joint structure 100 and stay in the closed space to form a refrigerant atmosphere having a flammable concentration.

Therefore, in an air conditioner that uses a flammable refrigerant, it is necessary to ensure reliability against refrigerant leakage. Therefore, the refrigerant pipe joint structure 100 used for indoor connection is submerged in water to allow water to infiltrate, and in that state, it is left below freezing to freeze, then thawed and frozen again. Is repeated so that it will not be damaged in that environment.

FIG. 6 is a cross-sectional view of the structure of the refrigerant pipe joint structure 1000 as a comparative example of the refrigerant pipe joint structure 100 according to the first embodiment. In the refrigerant pipe joint structure 1000 of the comparative example, the flare nut 1001, the copper pipe 10, and the union 7 are combined in the same manner as in the refrigerant pipe joint structure 100 according to the first embodiment. That is, the flare portion 11 of the copper tube 10 is sandwiched between the flare sheet surface 2 and the sheet surface 8 to ensure the sealing property.

The refrigerant pipe joint structure 1000 of the comparative example includes a relief shape 3 that allows the tip portion 12 of the flare portion 11 of the copper pipe 10 to escape, and is provided from the outer peripheral surface 15 of the flare nut 1001 so that the relief shape 3 and the external space communicate with each other. A communication hole 1005 is formed toward the relief shape 3. The communication hole 1005 is a drain hole, and dew condensation water is generated in the relief shape 3, and the pressure when it freezes and expands is released. The communication hole 1005 is formed from a direction orthogonal to the central axis of the cylindrical through hole 6, the female screw portion 4, and the relief shape 3. Therefore, in forming the flare nut 1001, it is necessary to apply the tool from a direction different from the tool for forming the through hole 6, the female screw portion 4, and the relief shape 3.

That is, in order to form the through hole 6, the female screw portion 4, and the relief shape 3 of the flare nut 1001, the material or tool of the flare nut 1 is rotated and processed around the central axis thereof. However, the communication hole 1005 needs to be drilled in the outer peripheral surface 15 of the flare nut 1001. As described above, the process of opening the communication hole 1005 is a process different from the process of forming the shape of the flare nut 1001, so that there is a problem that the productivity is lowered.

On the other hand, as shown in FIGS. 2 and 3, the flare nut 1 according to the first embodiment has a communication having a central axis parallel to the central axes of the through hole 6, the female screw portion 4, and the relief shape 3. It is provided with a hole 5. The communication hole 5 opens at the end surface 14 on the side where the union 7 of the flare nut 1 is inserted, and communicates the external space with the relief shape 3. The communication hole 5 has a central axis parallel to the central axis of processing for forming the flare nut 1. Therefore, the processing of the through hole 6 through which the copper pipe 10 of the flare nut 1 is passed, the flare sheet surface 2, the relief shape 3, and the female screw portion 4 for screwing with the union 7 and the processing of the communication hole 5 are a series of processes. It can be processed in the process.

The communication hole 5 is for discharging the dew condensation water inside the refrigerant pipe joint structure 100. Therefore, in order to allow drainage from the communication hole 5 regardless of the angle at which the flare nut 1 is installed in the rotation direction, the flare nut 1 is placed at three locations every 120 ° on the circumference centered on the central axis. It is provided.

Further, since the communication hole 5 is drilled, metal chips, which are the material of the flared nut 1 that has been shaved, may be generated and remain inside the communication hole 5 and the flare nut 1. In the flare nut 1 according to the first embodiment, the opening 5a of the communication hole 5 faces in the same direction. Therefore, when the chips are blown off with compressed air and removed, the compressed air can be flowed into the three communication holes 5 at the same time by closing the holes in which the female screw portion 4 is formed, and the chips can be efficiently removed. It can be removed.

As described above, the refrigerant pipe joint structure 100 according to the first embodiment has a copper pipe 10 including a pipe portion 18 and a flare portion 11 whose end portion of the pipe portion 18 is expanded into a conical shape, and a tip end thereof. A union 7 having a conical portion and having a refrigerant flow path 17 on the central axis, and a flare nut 1 having a female screw portion 4 screwed with the male screw portion 9 of the union 7 are provided. The flare nut 1 is formed between the through hole 6 through which the pipe portion 18 of the copper pipe 10 is passed, the relief shape 3 formed at the end of the female screw portion 4, and the relief shape 3 and the through hole 6. It is provided with a conical flare sheet surface 2 and a communication hole 5 for communicating the relief shape 3 and the external space. The union 7 is screwed and fastened to the female screw portion 4. The flare portion 11 of the copper tube 10 is sandwiched between the flare seat surface 2 and the seat surface 8 of the union 7. The communication hole 5 is open to the end surface 14 on which the female threaded portion 4 is formed, and the central axis is parallel to the central axis of the female threaded portion 4. With this configuration, even if the water accumulated inside the flare nut 1 freezes and expands, the expansion pressure is released from the communication hole 5, and the flare portion 11 of the copper tube 10 is pushed out by the frozen ice. It has the effect of preventing it from falling off. Further, by making the direction in which the communication hole 5 is machined and the direction of the central axis in which the structure of the female screw portion 4 or the like of the flare nut 1 is machined the same, the structure of the female screw portion 4 or the like can be obtained in the same processing process. It becomes possible to process the communication hole 5. As a result, it is not necessary to provide a separate process for processing the communication hole 5, and the productivity of the flare nut 1 is improved. That is, according to the refrigerant pipe joint structure 100 according to the first embodiment, by providing the above configuration, it is possible to suppress the cost while ensuring the reliability against the refrigerant leakage.

Embodiment 2.
The refrigerant pipe joint structure 200 according to the second embodiment of the present invention is obtained by changing the arrangement of the communication holes 5 with respect to the refrigerant pipe joint structure 100 according to the first embodiment. In the refrigerant pipe joint structure 200 according to the second embodiment, the changes to the first embodiment will be mainly described. Regarding each part of the refrigerant pipe joint structure 200 according to the second embodiment, those having the same function in each drawing shall be indicated with the same reference numerals as those used in the description of the first embodiment.

FIG. 7 is a plan view and a cross-sectional view of the flare nut 1 of the refrigerant pipe joint structure 200 according to the second embodiment. FIG. 8 is an enlarged view of a portion B of FIG. 7. The refrigerant pipe joint structure 200 according to the second embodiment replaces the flare nut 1 of the refrigerant pipe joint structure 100 according to the first embodiment with the flare nut 201 shown in FIG. 7. In the refrigerant pipe joint structure 200, the flare portion 11 of the copper pipe 10 is sandwiched between the flare seat surface 2 of the flare nut 1 and the seat surface 8 of the union 7 to ensure the sealing property. That is, the female screw portion 4 of the flare nut 201 and the male screw portion 9 of the union 7 mesh with each other, and the flare nut 1 is tightened by rotating with a tool or the like, and the flare portion 11 of the copper tube 10 and the flare sheet surface of the flare nut 201 are tightened. 2 and the seat surface 8 of the union 7 are in close contact with each other. As a result, the refrigerant flowing in the copper pipe 10 is sealed inside the refrigerant circuit. Further, when the screw is tightened, the flare portion 11 of the copper tube 10 is compressed by the seat surface 8 of the union 7 and the flare seat surface 2 of the flare nut 201 and extends in the direction of the tip portion 12 of the flare portion 11. .. Therefore, even if the tip portion 12 of the flare portion 11 of the copper tube 10 extends to the flare nut 201, the tip of the flare portion 11 of the copper tube 10 does not come into contact with the inner peripheral surface 16 of the flare nut 201. A relief shape 3 is provided to form a space for the portion 12 to escape.

Similar to the communication hole 5 of the flare nut 1 according to the first embodiment, the flare nut 201 has an opening 205a provided in the end surface 14 provided with the female screw portion 4, and is a center for processing the female screw portion 4 and the like. The communication hole 205 is arranged so as to be a central axis parallel to the axis. The communication hole 205 communicates the relief shape 3 with the external space. The communication hole 205 can be machined with the flare sheet surface 2, the relief shape 3, the female screw portion 4, and the through hole 6 in a series of steps.

In the flare nut 201 of the second embodiment, the communication hole 205 is provided, and the communication hole 205 is provided on the virtual line connecting the corner portion 19 and the central axis of the flare nut 201. As a result, the fact that the corner portion 19 of the flare nut 201 is thickened can be utilized to increase the distance between the female screw portion 4 of the flare nut 201 and the communication hole 205. As a result, the wall thickness between the female screw portion 4 and the communication hole 205 increases, so that the strength of the flare nut 201 can be increased.

Further, by reducing the inner diameter dimension 20 of the inner peripheral surface 16 of the relief shape 3 for releasing the tip portion 12 of the flare portion 11 of the copper tube 10, the inner peripheral surface 16 of the relief shape 3 and the outer peripheral surface of the flare nut 201 are reduced. The distance from 15 can be increased. Therefore, the strength of the flare nut 201 can be increased. At this time, the inner diameter dimension 20 of the relief shape 3 is set to be equal to or greater than the distance 21 between the central axis of the communication hole 205 and the central axis of the flare nut 201. As a result, it is possible to secure the opening area of the opening 22 in which the relief shape 3 and the communication hole 205 communicate with each other. Further, it is possible to secure a path for releasing the pressure when the water staying in the relief shape 3 expands when it freezes, while suppressing the decrease in strength due to the processing of the communication hole 205. As a result, it is possible to prevent the tip portion 12 of the flare portion 11 of the copper tube 10 from being pushed out by ice and the sealing property from being deteriorated.

In the refrigerant pipe joint structure 200 according to the second embodiment, the distance between the central axis of the communication hole 205 and the central axis of the female threaded portion 4 is equal to or less than the inner diameter dimension 20 of the inner peripheral surface 16 of the relief shape 3. The flare nut 201 has a hexagonal outer peripheral surface 15 when viewed in the direction of the central axis of the female threaded portion 4, and the communication hole 205 is formed with the apex of the outer peripheral surface 15 of the flare nut 201 and the central axis of the female threaded portion 4. It is located on the virtual line connecting the. As a result, the refrigerant pipe joint structure 200 can improve the strength of the flare nut 201 while obtaining the same effect as the refrigerant pipe joint structure 100 according to the first embodiment.

Although the present invention has been described above based on the embodiments, the present invention is not limited to the configuration of the above-described embodiments. For example, the communication holes 5 and 205 may be provided at more locations. Further, the present invention may be configured by combining each embodiment. In short, it should be added that the gist (technical scope) of the present invention also includes various modifications, applications, and uses made by those skilled in the art as necessary.

1 flare nut, 2 flare seat surface, 3 relief shape, 4 female screw part, 5 communication hole, 5a opening, 6 through hole, 7 union, 8 seat surface, 9 male screw part, 10 copper pipe, 11 flare part, 12 Tip, 13 End, 14 End, 15 Outer, 16 Inner, 17 Coolant Flow Path, 18 Pipe, 19 Square, 20 Inner Diameter, 21 Distance, 22 Opening, 100 Flood Pipe Fitting Structure, 200 Refrigerant pipe joint structure, 201 flare nut, 205 communication hole, 205a opening, 1000 refrigerant pipe joint structure, 1001 flare nut, 1005 communication hole.

Claims (3)

A copper tube including a tube portion and a flared portion in which the end portion of the tube portion is expanded in a tapered shape.
A union that is formed in a tapered shape at the tip and has a refrigerant flow path on the central axis.
A flare nut having a female thread portion to be screwed with the union, and
The flare nut is
A through hole through which the tube portion of the copper tube is passed and
The relief shape formed at the end of the female screw portion and
A tapered flare sheet surface formed between the relief shape and the through hole,
A communication hole for communicating the relief shape and the external space is provided.
The union is
It has a tapered seat surface at the tip and a male screw portion formed on the side surface.
It is screwed and fastened to the female screw part,
The flared portion of the copper tube
It is sandwiched between the flare sheet surface and the sheet surface of the union,
The communication hole is
A refrigerant pipe joint structure that is open to the end face on which the female threaded portion is formed, and the central axis of the communication hole is parallel to the central axis of the female threaded portion. The distance between the central axis of the communication hole and the central axis of the female threaded portion is
The refrigerant pipe joint structure according to claim 1, which is set to be equal to or smaller than the inner diameter of the inner peripheral surface of the relief shape. The flare nut is
The outer peripheral surface is hexagonal when viewed in the direction of the central axis of the female screw portion.
The communication hole is
The refrigerant pipe joint structure according to claim 1 or 2, which is located on a virtual line connecting the apex of the outer peripheral surface of the flare nut and the central axis of the female thread portion.

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