WO2020174517A1

WO2020174517A1 - Refrigerant pipe joint structure

Info

Publication number: WO2020174517A1
Application number: PCT/JP2019/006982
Authority: WO
Inventors: 宗介西田; 牧野　浩招
Original assignee: 三菱電機株式会社
Priority date: 2019-02-25
Filing date: 2019-02-25
Publication date: 2020-09-03
Also published as: JP7123232B2; JPWO2020174517A1

Abstract

The purpose of the present invention is to obtain a refrigerant pipe joint structure in which the productivity of a flare nut provided with a water-draining hole is improved, and cost is minimized while maintaining reliability against refrigerant leakage. This invention comprises: a copper pipe provided with a pipe part and a flare part in which both ends of the pipe part are enlarged into tapers; a union formed into a taper at a distal end part and provided with a refrigerant flow channel along a center axis; and a flare nut provided with a female screw part that threads together with the union. The flare nut is provided with a through-hole through which the pipe part of the copper pipe is passed, a relief shape formed in an end part of the female screw part, a tapered flare seat surface formed between the relief shape and the through-hole, and a communication hole allowing communication between the relief shape and an external space. The union is provided with a tapered seat surface at the distal end and a male screw part formed in a side surface and is fastened by threading together with the female screw part, the flare part of the copper pipe is held between the flare seat surface and the seat surface of the union, the communication hole opens into the end surface in which the female screw part is formed, and the center axis of the communication hole is parallel to the center axis of the female screw part.

Description

Refrigerant piping joint structure

The present invention relates to a refrigerant pipe joint structure of a refrigeration cycle device, and particularly to a water drain 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 and outdoor connecting pipes that connect the indoor unit and the outdoor unit to the indoor unit and the outdoor unit. In recent years, a combustible refrigerant such as R32 has been used as a refrigerant for an air conditioner to prevent global warming. If such a flammable refrigerant leaks and stays in the closed space, it may be mixed with air and 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.

Flare joint seals by flaring a copper tube between the union and flare nut seat surface. As a result, the coolant flowing in the copper pipe is sealed so as not to leak outside. The flare nut and the union are fastened with a screw and fastened with 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).

JP, 2005-155726, A

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. It is compressed by the axial force, becomes thinner, and extends toward the tip of the flare portion of the copper tube. Therefore, the flare nut is configured so as not to contact the inner peripheral surface of the flare nut even if the tip of the flare portion extends. When the contact area between the flare portion of the copper tube and the seat surfaces of the union and the flare nut is set large in order to improve the sealing property, the flare nut is provided with a space for allowing the tip of the extending flare portion 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 be collected 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 to 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 frozen 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 flare portion of the copper pipe comes out of the joint, the sealing property is lost, and the refrigerant flowing in the copper pipe is released into the atmosphere. The flammable refrigerant may stay in the closed space and be mixed with air to a concentration at which the refrigerant burns.

As a countermeasure against this, in the conventional flare nut, a drainage hole is provided from the side surface of the flare nut so as to connect the space for allowing the tip of the flare portion to communicate with the external space, and the pressure generated by the expansion of ice due to freezing is released. .. The flare nut is processed by rotating the flare nut or a tool around the central axis of the screw. On the other hand, in the flare nut in which the drainage 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 perforation processing. In this case, for example, the process of forming the screw of the flare nut and the process of forming the water drain hole are performed in different processing steps, so that there is a problem that productivity is reduced.

The present invention is to solve the above problems, and an object of the present invention is to obtain a refrigerant pipe joint structure with improved productivity of flare nuts provided with drain holes.

The refrigerant pipe joint structure according to the present invention is a copper pipe provided with a pipe portion and a flare portion in which an end portion of the pipe portion is expanded in a tapered shape, and a tapered portion is formed at a tip end portion on a central axis. A flare nut including a union including a coolant channel and a female screw portion that is screwed into the union, wherein the flare nut includes a through hole through which the pipe portion of the copper pipe is passed, and the female screw portion. An escape shape formed at an end portion of, a tapered flare sheet surface formed between the escape shape and the through hole, and a communication hole that communicates the escape shape and an external space, The union includes a tapered seat surface at a tip and a male screw portion formed on a side surface, and is screwed and fastened to the female screw portion, and the flare portion of the copper tube is the flare sheet. Sandwiched between a surface and the seat surface of the union, the communication hole is opened at an end face where the female screw portion is formed, and the central axis of the communication hole is the central axis of the female screw portion. Parallel to.

ADVANTAGE OF THE INVENTION According to this invention, even if the water accumulated inside the flare nut freezes and expands, the expansion pressure is released from the communication hole, so that the flare portion of the copper pipe is pushed out by the frozen ice and does not fall off. Have. At the same time, by making the direction of processing the communication hole and the direction of the central axis for processing the structure such as the flare nut screw, the communication hole can be processed in the same processing step. As a result, when processing the flare nut, there is no need to provide a separate process for processing the communication hole, and the productivity of the flare nut is improved.

1 is an external view of a refrigerant pipe joint structure 100 according to a first embodiment. FIG. 3 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 sectional view of the flare nut 1 of FIG. 2. It is sectional drawing of the edge part of the copper tube 10 of FIG. It is sectional drawing of the edge part of the union 7 of FIG. FIG. 3 is a sectional view of a structure of a refrigerant pipe joint structure 1000 as a comparative example of the refrigerant pipe joint structure 100 according to the first embodiment. 5A and 5B are a plan view and a sectional view of a flare nut 1 of a refrigerant pipe joint structure 200 according to a second embodiment. It is an enlarged view of the B section of FIG.

An embodiment of the refrigerant pipe joint structure will be described below. The drawings are merely examples, and the present invention is not limited thereto. In addition, the same reference numerals in the drawings are the same or equivalent, and this is common to all the texts in the specification. Furthermore, in the following drawings, the size relationship of each component may be different from the actual one.

Embodiment 1.
FIG. 1 is an external view of a 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 to an inside/outside connection pipe that connects 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 inside/outside connection pipe, and the copper pipe 10 and the union 7 to each other. And a flare nut 1 for sealing the refrigerant.

　In split type air conditioners, flare joints are used to connect the indoor and outdoor connecting pipes that connect the indoor unit and the outdoor unit to the indoor 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, there is a possibility that the refrigerant leaks into the atmosphere, stays in a closed space, is mixed with air, and has a concentration at which the refrigerant burns. For this reason, the flare joint is required to have higher reliability against refrigerant leakage from the joint than in the case of using a nonflammable refrigerant such as R410A. The refrigerant pipe joint structure 100 secures the sealing property and suppresses the refrigerant leakage 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 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 portion of the union 7 of FIG. In FIG. 2, only the upper half shows the entire sectional structure, and the lower half shows the 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 portion is expanded in a conical shape, a through hole 6 through which the copper pipe 10 is inserted, and a flare portion 11. The flare nut 1 having a flare seat surface 2 that is a conical surface that contacts with a union 7 having a conical seat surface 8 at the tip end is combined.

The copper tube 10 is passed through the through hole 6 of the flare nut 1 and extends to the one end surface 13 side 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 where 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 sheet 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 sheet surface 2 of the flare nut 1 and the seat surface 8 at the tip of the union 7. .. The flare portion 11 is compressed and deformed between the flare sheet surface 2 and the sheet surface 8 of the union 7 and comes into close contact with the flare sheet surface 2 and the sheet surface 8, whereby the sealing property is secured.

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 at the center of the hexagon from one end surface 13 side. And a female screw portion 4 provided at the center of the hexagon from the other end face 14 side. Between the through hole 6 and the female threaded portion 4, a flared sheet surface 2 having a tapered shape and a relief shape 3 for preventing the tip portion 12 of the flared portion 11 from coming into contact with 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 that expands with respect to the inner diameter of the through hole 6. Furthermore, the flare sheet surface 2 is a conical surface. The escape shape 3 is formed between the flare sheet surface 2 and the female screw portion 4. On the female screw portion 4 side of the flare sheet surface 2, a cylindrical inner peripheral surface 16 larger than the inner diameter dimension of the end of the flare sheet surface 2 on the side where the diameter is expanded is formed. The tip portion 12 of the flare portion 11 is configured to escape into the formed space. The inner peripheral surface 16 of the escape 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 of the flare nut 1 on which the female screw portion 4 is formed toward the relief shape 3. The communication hole 5 is opened in the end surface 14 and communicates the external space with the space formed inside the flare nut 1 formed by the relief shape 3.

As shown in FIG. 4, the copper pipe 10 has an enlarged flare nut 1 side end portion, and forms a flared portion 11 that is enlarged in a tapered shape. As shown in FIG. 5, the union 7 is provided with a coolant passage 17 which is a hole through which a coolant flows in the central portion, and the tip portion is formed in a truncated cone shape whose outer diameter is reduced toward the tip. ing. A coolant passage 17 that is a hole through which a coolant flows is opened in a truncated cone-shaped end surface at the tip of the union 7. The tapered surface at the tip of the union 7 is the seat surface 8 that contacts the flare portion 11. That is, the union 7 is provided with a tapered seat surface 8 at the tip. In Embodiment 1, flare sheet surface 2, sheet surface 8 and flare portion 11 are formed so as to form an angle of 45 degrees with the central axis in the cross sections shown in FIGS. 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 can be appropriately changed in shape as long as they are 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 sealability is secured by. The female screw portion 4 of the flare nut 1 and the male screw portion 9 of the union 7 are screwed together, and the flare nut 1 is rotated and tightened by 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 comes into close contact with the flare sheet 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 tube 10 is sealed. When tightening the screw, the flare portion 11 of the copper tube 10 is compressed by the seat surface 8 of the union 7 and the flare sheet surface 2 of the flare nut 1, so that the flare portion 11 of the copper tube 10 becomes slightly thinner. It deforms and extends in the direction of the tip 12 of the flare 11 of the copper tube 10. Since the flare nut 1 is formed with the relief shape 3 that allows the tip 12 of the flare portion 11 of the copper tube 10 to escape, even if the tip 12 of the flare portion 11 of the copper tube 10 extends, 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 decreases, condensed water may be generated inside the refrigerant pipe joint structure 100, and condensed water may be accumulated in the escape shape 3 for allowing the tip 12 of the flare portion 11 of the copper pipe 10 to escape. In addition, when the temperature of the refrigerant pipe joint structure 100 is lowered to a temperature below the freezing point, the frozen water of the condensed dew condensation water expands, and the tip 12 of the flare portion 11 of the copper pipe 10 is pressed against the expanded ice. Be 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 between the flare sheet surface 2 of the flare nut 1 and the seat surface 8 of the union 7. Be done. Then, the flare portion 11 comes out between the flare sheet surface 2 and the sheet surface 8, the sealing property is lost, 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 air conditioners that use flammable refrigerant, it is necessary to ensure reliability against refrigerant leakage. Therefore, the refrigerant pipe joint structure 100 used for indoor connection is a process in which the refrigerant pipe joint structure 100 is submerged in water to allow water to penetrate into the inside, left in that state below freezing to be frozen, and then thawed and then frozen again. Repeatedly, it is configured not to be damaged under the environment.

FIG. 6 is a sectional view of a structure of a 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 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 from the outer peripheral surface 15 of the flare nut 1001 so that the relief shape 3 communicates with the external space. A communication hole 1005 is formed toward the relief shape 3. The communication hole 1005 is a water draining hole and releases the pressure when dew condensation water is generated in the escape shape 3 and freezes and expands. The communication hole 1005 is formed in a direction orthogonal to the central axis of the cylindrical through hole 6, the female screw portion 4, and the relief shape 3. Therefore, when forming the flare nut 1001, it is necessary to apply a tool from a direction different from the direction of the tool that forms 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 escape shape 3 of the flare nut 1001, the material or tool of the flare nut 1 is rotated around the central axis thereof and processed. However, the communication hole 1005 needs to be formed in the outer peripheral surface 15 of the flare nut 1001. As described above, since the process of forming the communication hole 1005 is a process different from the process of forming the shape of the flare nut 1001, there is a problem that productivity is reduced.

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

The communication hole 5 is for discharging condensed water inside the refrigerant pipe joint structure 100. Therefore, the flare nut 1 can be drained from the communication hole 5 at any angle in the rotation direction, so that the flare nut 1 can be drained from the communication hole 5 at three positions every 120° on the circumference around the central axis of the flare nut 1. It is provided.

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

As described above, the refrigerant pipe joint structure 100 according to the first embodiment has the copper pipe 10 including the pipe portion 18 and the flare portion 11 in which the end portion of the pipe portion 18 is expanded in a conical shape, and the tip. The portion is formed in a conical shape, and includes a union 7 having a coolant channel 17 on the central axis thereof, and a flare nut 1 having a female screw portion 4 screwed with a male screw portion 9 of the union 7. The flare nut 1 is formed between the through hole 6 through which the pipe portion 18 of the copper pipe 10 passes, the relief shape 3 formed at the end of the female screw portion 4, and the escape shape 3 and the through hole 6. And a conical flare sheet surface 2 and a communication hole 5 that communicates the relief shape 3 with 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 sheet surface 2 and the sheet surface 8 of the union 7. The communication hole 5 is opened in the end surface 14 on which the female screw portion 4 is formed, and its central axis is parallel to the central axis of the female screw portion 4. With such a 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 pipe 10 is pushed out by the frozen ice. It has the effect of not falling off. Further, by making the direction in which the communication hole 5 is processed and the direction of the central axis for processing the structure of the female screw portion 4 and the like of the flare nut 1 the same, the structure of the female screw portion 4 and the like can be made in the same processing step. 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 reduce the cost while ensuring reliability against refrigerant leakage.

Embodiment 2.
Refrigerant pipe joint structure 200 according to Embodiment 2 of the present invention differs from refrigerant pipe joint structure 100 according to Embodiment 1 in that the arrangement of communication holes 5 is changed. The refrigerant pipe joint structure 200 according to the second embodiment will be described with a focus on the changes from the first embodiment. Regarding the respective parts of the refrigerant pipe joint structure 200 according to the second embodiment, those having the same function in each drawing will be denoted by the same reference numerals as those in the drawings used in the description of the first embodiment.

FIG. 7 is a plan view and a 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 portion B in FIG. 7. The refrigerant pipe joint structure 200 according to the second embodiment is obtained by replacing the flare nut 1 of the refrigerant pipe joint structure 100 according to the first embodiment with a 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 sheet surface 2 of the flare nut 1 and the seat surface 8 of the union 7 to ensure sealing performance. That is, the female screw portion 4 of the flare nut 201 and the male screw portion 9 of the union 7 are engaged with each other, and the flare nut 1 is rotated by a tool or the like to tighten the flare nut 11 and the flare sheet surface of the flare nut 201. 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 tube 10 is sealed inside the refrigerant circuit. Further, when tightening the screw, the flare portion 11 of the copper tube 10 is compressed by the seat surface 8 of the union 7 and the flare sheet 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 which forms a space for the portion 12 to escape.

Like the communication hole 5 of the flare nut 1 according to the first embodiment, the flare nut 201 is provided with an opening 205a 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 that the central axis is parallel to the axis. The communication hole 205 communicates the relief shape 3 with the external space. The communication hole 205 can be processed by 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 a virtual line connecting the corner portion 19 and the central axis of the flare nut 201. This makes it possible to increase the distance between the female screw portion 4 of the flare nut 201 and the communication hole 205 by utilizing the fact that the corner portion 19 of the flare nut 201 is thick. 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 escape shape 3 for allowing the tip portion 12 of the flare portion 11 of the copper pipe 10 to escape, the inner peripheral surface 16 of the escape shape 3 and the outer peripheral surface of the flare nut 201. The distance from 15 can be separated. 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 more 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, the opening area of the opening 22 through which the relief shape 3 and the communication hole 205 communicate can be secured. In addition, it is possible to secure a path for releasing the pressure when the water retained in the escape 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 performance being deteriorated.

In the refrigerant pipe joint structure 200 according to the second embodiment, the distance between the center axis of the communication hole 205 and the center axis of the female screw 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 screw portion 4, and the communication hole 205 defines the apex of the outer peripheral surface 15 of the flare nut 201 and the central axis of the female screw portion 4. It is located on the virtual line that connects the two. Thereby, refrigerant pipe joint structure 200 can improve the strength of flare nut 201 while obtaining the same effect as 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 configurations of the above-described embodiments. For example, the communication holes 5 and 205 may be provided in more places. Further, the present invention may be configured by combining the embodiments. In short, it should be added that the scope of the present invention (technical scope) also includes various modifications, applications, and ranges of use that are required by those skilled in the art.

1 flare nut, 2 flare seat surface, 3 relief shape, 4 female screw part, 5 communicating hole, 5a opening part, 6 through hole, 7 union, 8 seat surface, 9 male screw part, 10 copper pipe, 11 flare part, 12 tip part, 13 end face, 14 end face, 15 outer peripheral face, 16 inner peripheral face, 17 refrigerant flow passage, 18 pipe part, 19 corner part, 20 inner diameter dimension, 21 distance, 22 opening part, 100 refrigerant pipe joint 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

A copper pipe comprising a pipe portion and a flare portion in which an end portion of the pipe portion is expanded in a tapered shape;
With a union that is formed in a tapered shape at the tip and has a refrigerant channel on the central axis,
A flare nut having a female screw portion that is screwed into the union,
The flare nut is
A through hole through which the tube portion of the copper tube is passed,
A relief shape formed at the end of the female screw portion,
A tapered flare sheet surface formed between the escape shape and the through hole,
A communication hole that communicates the escape shape with the external space,
The union is
A tapered seat surface at the tip, and a male screw portion formed on the side surface,
It is screwed and fastened with the female screw portion,
The flare portion of the copper tube,
Sandwiched between the flare sheet surface and the union sheet surface,
The communication hole is
A refrigerant pipe joint structure having an opening on an end surface on which the female screw portion is formed, and a central axis of the communication hole is parallel to a central axis of the female screw portion.
The distance between the central axis of the communication hole and the central axis of the female screw portion is
The refrigerant pipe joint structure according to claim 1, wherein the refrigerant pipe joint structure is set to be equal to or smaller than the inner diameter dimension of the inner peripheral surface of the relief shape.
The flare nut is
The outer peripheral surface is a hexagon when viewed in the central axis direction of the female screw portion,
The communication hole is
The refrigerant pipe joint structure according to claim 1, wherein the refrigerant pipe joint structure is located on an imaginary line connecting the apex of the outer peripheral surface of the flare nut and the central axis of the female screw portion.