JP2006132653A - Double pipe, its manufacturing method, and supporting member of double pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive double pipe having an inner pipe and an outer pipe independently formed, and having a joint portion for easily connecting the double pipes with each other, and the double pipe and a connector such as a two-way branch joint, and further to provide a method of manufacturing the double pipe, and a supporting member for fixing the inner pipe and the outer pipe independently formed. <P>SOLUTION: This double pipe 1 has a first pipe (inner pipe) 20 of small diameter and a second pipe (outer pipe) 10 of large diameter, and the inner pipe 20 is mounted in the outer pipe 10. This double pipe has the supporting member 30 kept into contact with an outer peripheral face of the inner pipe 20, and further kept into contact with an inner peripheral face of the outer pipe 10 to support the inner pipe 20 at a prescribed position in the outer pipe 10. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a double pipe having an inner pipe inside an outer pipe. More specifically, the present invention relates to a double pipe in which an inner pipe and an outer pipe are separately formed, a manufacturing method thereof, and a support member that supports the inner pipe in the outer pipe.

  In general, in an air conditioner (hereinafter referred to as an air conditioner) constituting a refrigeration cycle, a pipe-like piping member is connected between a compressor, a condenser, an expansion valve, and an evaporator in order to circulate refrigerant. Since this piping member increases in cost as its length increases, in the air conditioner, it is arranged so as to shorten the arrangement distance of each device as much as possible. However, in particular, in the case where the air conditioner is mounted on a vehicle, for example, in a one-box type vehicle, the evaporator for the rear seat is arranged with the piping member extending on the rear side, so that the piping length Was extremely long.

  For this reason, conventionally, a double pipe is formed to save its length. One example of a double pipe is one in which an inner pipe and an outer pipe are connected by connecting ribs and are integrally formed by extrusion molding or pultrusion processing. It is disclosed in Patent Document 1.

  However, the use of a double pipe shortens the pipe length to reduce costs and save space. For example, it is not desirable to increase the cost by complicating the structure of connecting to a joint member. . In the configuration shown in the above prior art, the distal end portion of the outer tube must be cut in order to make the inner tube protrude, which increases the processing cost. In addition, the need for a connecting member for piping to the extending piping member as the outer pipe passage is also a factor for increasing the cost.

Furthermore, the joint member connecting the double pipes connects the two pipe members separately piped by the male part of the first joint member connecting the inner pipe and the outer pipe of one of the double pipes. After being joined to the female part of the second joint member to be connected, it is connected by a bolt or the like. Therefore, the connection between the double pipe and the joint member requires a lot of man-hours and cannot be instantaneously connected. . Further, since the first joint member and the second joint member are joined to the branched inner pipe and the outer pipe by brazing or welding, the respective joint members are enlarged and the inner pipe and It took a long time to join the outer tube.
JP 2001-235081 A

  The present invention has been made to solve the above-mentioned problems. The first object of the present invention is to form the inner pipe and the outer pipe as separate bodies, and double pipes or a double pipe and a two-way branch joint. It is an inexpensive double pipe having a joint portion that can be easily connected to the connector. The second object is to provide a manufacturing method for storing the double pipe as described above. A third object of the present invention is to provide a support member that fixes an inner tube and an outer tube formed separately.

  The double pipe of the present invention has a first pipe having a small diameter (hereinafter referred to as an inner pipe) and a second pipe having a diameter larger than that of the inner pipe (hereinafter referred to as an outer pipe). A double pipe disposed in the pipe, having a support member that contacts the outer peripheral surface of the inner pipe and supports the inner pipe at a predetermined position in the outer pipe by contacting the inner peripheral surface of the outer pipe. It is characterized by.

  The double pipe of the present invention has a support member that contacts the outer peripheral surface of the inner pipe and supports the inner pipe at a predetermined position in the outer pipe by contacting the inner peripheral surface of the outer pipe. It can be reliably held at a predetermined position inside the tube.

  In the double pipe of the present invention, it is desirable that the support member is located on the axially outer side of the step portion formed at the end of the outer tube and is engaged with the step portion.

  By disposing the support member so as to engage with the step portion of the outer tube, the support member can be prevented from entering the outer tube. In addition, since the support member can be easily mounted by arranging the support member at the end of the outer tube, the productivity of the double tube can be improved.

  Further, it is preferable that the support member is located on the inner side in the axial direction of the step portion formed at the end portion of the inner tube and is engaged with the step portion.

  By arranging the support member between the terminal step portion of the outer tube and the terminal step portion of the inner tube, the support member enters the outer tube and the inner tube moves in the axial direction of the outer tube. Can be prevented. In particular, in the case of a refrigeration cycle in which a high-pressure refrigerant is circulated through the inner pipe, a force acts in the direction in which the inner pipes are disconnected at the connection between the double pipes. By providing the supporting member to be engaged, the connection between the double tubes can be maintained extremely stably. Such a double pipe is suitable for use in a connection part between double pipes or a connector for connecting a double pipe and a conventional pipe.

  The double tube of the present invention can include a spacer member between the support member and the step portion of the inner tube. By inserting the spacer member between the support member and the step portion of the inner tube, the movement of the inner tube in the axial direction can be easily prevented.

  Moreover, it is good also as a double pipe provided with a supporting member in both ends, and having the above spacer members only at one end side. This type of double pipe can be connected to other double pipes at one end, and the other end is connected to a connector such as a two-way branch joint that connects to conventional pipes or functional parts such as pressure reducing valves. can do. Furthermore, since one end side can be fixed with a support member and the other end side can be easily fixed in the axial direction of the inner tube with the support member and the spacer, the productivity of the double tube can be improved. it can.

  The support member in the double pipe of the present invention can support the inner pipe by being positioned at the intermediate portion in the axial direction of the outer pipe (support that supports the inner pipe by being positioned at the intermediate portion in the axial direction of the outer pipe) The member is hereinafter referred to as an intermediate support member.) In a double pipe having such an intermediate support member, interference with the outer pipe due to the amplitude of the inner pipe can be suppressed by the intermediate support member, and abnormal noise and wear can be prevented.

  Further, the intermediate support member can be located at a bent portion of the outer tube. By disposing the intermediate support member in the bent portion of the outer tube, the intermediate support member can be fixed using the reduction in the cross section of the outer tube bent portion. Therefore, there is no movement of the intermediate support member in the axial direction, the inner tube can be supported in a stable state, and abnormal noise and wear can be prevented.

  The support member as described above is preferably made of a metal such as aluminum or a resin such as nylon or PPS. The support member made of a resin such as nylon or PPS is lightweight and can be easily attached to the inner tube by providing an opening. Moreover, it is preferable that the intermediate support member located in a bending part consists of metals, such as aluminum. When the intermediate support member located in such a bent part is formed of a resin with a small material elongation, the intermediate support member is greatly deformed in the bent part, so that the intermediate support is accompanied by a decrease in the bending section of the outer tube. The member may be compressed and buckled. For this reason, it is preferable to use a metal material such as aluminum or copper having a large elongation for the intermediate support member.

  The double pipe of the present invention is a pipe that connects components of the refrigeration cycle, and is preferably a double pipe through which a refrigerant flows. For example, as a component of the refrigeration cycle, a pipe that connects an indoor heat exchanger or an evaporator with an expansion valve, which is disposed at a position close to the passenger compartment away from the engine room, to other components disposed in the engine room By using the double pipe of the present invention, the high-pressure refrigerant directed to the evaporator is circulated in the inner pipe, and the low-pressure refrigerant directed from the evaporator to the compressor is circulated in the outer passage between the inner pipe and the outer pipe. In addition, the pipe length can be shortened to reduce costs and save space.

  The method for producing a double tube of the present invention is a method for producing a double tube having a small diameter inner tube and an outer tube having a larger diameter than the inner tube, and the inner tube is disposed in the outer tube, A stepped portion forming step for forming stepped portions at both ends of the inner tube and the outer tube, and a support member mounting for fixing the inner tube in the outer tube with a support member that supports the inner tube and engages the stepped portion of the outer tube. And an inner tube fixing step in which a support member is attached to the other end and a spacer member is attached to the protruding portion of the inner tube to fix the inner tube in the axial direction.

  According to the method of manufacturing a double pipe of the present invention, first, after forming a stepped portion at both ends of the inner pipe and the outer pipe, after fixing the inner pipe on one end side in the outer pipe using a support member, The other end side is fixed with a similar support member, and the axial movement of the inner tube is further suppressed by the spacer member. Therefore, the inner tube can be easily arranged in the outer tube, and the productivity of manufacturing a double tube is achieved. Can be improved.

  In addition, the manufacturing method of the double pipe of the present invention includes an assembling step of incorporating an inner pipe in which an intermediate support member that supports the inner pipe at an intermediate portion in the axial direction of the outer pipe is installed in the outer pipe, and the inner pipe is attached to the inner pipe. A bending step of bending the inner tube and the outer tube to a predetermined angle together with the intermediate support member can be further included. By having these steps, a double pipe having a desired bent shape can be stably formed.

  Here, it is preferable to temporarily fix the intermediate support member to the inner tube with an adhesive or caulking before the assembly step. By temporarily fixing the intermediate support member to the inner tube and then bending it by inserting it into the outer tube, it is possible to reliably perform the bending process at the position where the intermediate support member is provided.

  The double-tube support member of the present invention has a small-diameter inner tube and a larger-diameter outer tube than the inner tube, and the inner tube is disposed in the outer tube. It is located between the level | step-difference part of an inner tube, and the level | step-difference part of an outer tube, and supports an inner tube | pipe in the predetermined position of an outer tube | pipe.

  The support member for the double pipe of the present invention is located between the step portion of the inner tube and the step portion of the outer tube and supports the inner tube at a predetermined position of the outer tube, so that the support member enters the outer tube. And the inner tube does not move inward of the outer tube in the axial direction.

  Further, the double pipe support member of the present invention has an inner pipe support part for supporting the inner pipe and a plurality of fin portions protruding on the outer periphery of the inner pipe support part. It is desirable to provide an opening for inserting the inner tube in the radial direction.

  The double pipe support member of the present invention is in contact with the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube by the inner tube support portion and the plurality of fin portions protruding from the inner tube support portion. Can be supported in the outer tube. Further, since the inner tube support portion is provided with the opening, the inner tube can be gripped from the radial direction instead of the axial direction, so that the support member can be easily mounted. Therefore, the inner tube can be easily fixed at the end of the outer tube.

  The support member of the double pipe of the present invention is a pipe that connects the components of the refrigeration cycle, and it is desirable that the coolant flows inside and the support member is disposed in the coolant. For example, as a component of the refrigeration cycle, a pipe that connects an indoor heat exchanger or an evaporator with an expansion valve, which is disposed at a position close to the passenger compartment away from the engine room, to other components disposed in the engine room By using the support member of the double pipe of the present invention, the high-pressure refrigerant directed to the evaporator is circulated in the inner pipe, and the low-pressure refrigerant directed from the evaporator to the compressor is disposed in the outer passage between the inner pipe and the outer pipe. Can be circulated, and the piping length can be shortened to reduce costs and save space. Further, interference with the outer tube due to the amplitude of the inner tube can be suppressed, and abnormal noise and wear can be prevented.

  A preferred embodiment of the double pipe of the present invention will be described with reference to the drawings. In addition, the same code | symbol was attached | subjected about the same part in each figure.

  The double pipe of the present invention, the supporting member thereof, and the manufacturing method thereof include an inner passage formed in a first pipe as an inner pipe arranged on the inner side, and an outer pipe arranged on the outer side of the inner pipe. The second pipe is used for the purpose of circulating different fluids in the outer passage formed between the inner surface of the second pipe and the outer surface of the inner pipe. Different fluids are fluids that have different physical or chemical properties such as pressure, temperature, flow direction, and the like.

  For example, the double pipe of the present invention, its support member, and its manufacturing method can be used as piping for connecting the components of the refrigeration cycle constituting the cooling device, the refrigeration device, and the like. Different refrigerants such as pressure and temperature can flow through the inner passage and the outer passage. In this case, it is desirable that the support member is disposed so as to be immersed in the refrigerant, and is provided with a shape and an arrangement capable of suppressing pressure loss with respect to the refrigerant flow.

  The double pipe can be used, for example, as a pipe of a vehicle air conditioner. For example, as a component of the refrigeration cycle, a pipe that connects an indoor heat exchanger or an evaporator with an expansion valve, which is disposed at a position close to the passenger compartment away from the engine room, to other components disposed in the engine room Can be used as For example, the high-pressure refrigerant directed to the evaporator can be circulated in the inner passage, and the low-pressure refrigerant directed from the evaporator to the compressor can be circulated in the outer passage.

[First Embodiment]
As shown in FIG. 1A, the double tube 1 according to the first embodiment includes an outer tube 10 having one end formed in a female-side joint shape, and an end portion inserted into the outer tube 10 and a male end. An inner tube 20 formed in a side joint shape and a support member 31 that supports the inner tube 20 in the outer tube 10 are provided. The outer tube 10 is identified as a large-diameter tube by the diameter of the general cylindrical portion 11 that occupies most of the axial range. Further, the inner tube 20 is identified as a tube having a smaller diameter than the outer tube 10 by the diameter of the general cylindrical portion 21 that occupies most of the axial range.

  The outer tube 10 has a diameter-enlarged portion 12 that is larger than the outer diameter of the general cylindrical portion 11, and a diameter-reduced portion 13 that is continuously reduced to the general cylindrical portion 11 after the diameter-enlarged portion 12. The diameter-reduced portion 13 is formed as a step portion formed between the large-diameter portion 12 and the general cylindrical portion 11. The reduced diameter portion 13 is formed in a tapered shape that extends from the general cylindrical portion 11 toward the end of the outer tube 10, and is a portion that can also be referred to as a tapered portion.

  Further, the inner tube 20 is formed with a seal groove portion 22 having a diameter smaller than the outer diameter of the general cylindrical portion 21 and a bulging portion 23 protruding radially from the general cylindrical portion 21 in the circumferential direction in order from the terminal side. The bulging portion 23 is a step portion formed between the general cylindrical portion 21 and the bulging portion 23. The bulging portion 23 is a portion that can be referred to as a flange portion, a bulge portion, or a fold-out portion formed by expanding the diameter from the general tubular portion 21 toward the end portion of the inner tube 20. An O-ring 50 is mounted in the seal groove of the seal groove portion 22.

  As shown in FIG. 1B, the support member 31 contacts an inner tube support portion (hereinafter referred to as an insertion portion) 31 a that passes through the general tube portion 21 of the inner tube 20 and a reduced diameter portion 13 of the outer tube 10. A plurality of fin portions 31b in contact with each other are integrally formed.

  In this embodiment, as shown in FIG. 1B, four fin portions 31b are provided as the plurality of fin portions 31b. Two or more fin portions 31b can be provided. The fin portions 31b can be provided at equal intervals, and three or more fin portions 31b can be provided at equal intervals in consideration of stability.

  The four fin portions 31b illustrated in FIG. 1B extend radially from the insertion portion 31a along the radial direction. Each fin portion 31 b has a flat plate shape extending in parallel with the axial direction of the outer tube 10 and the inner tube 20. Each of the fin portions 31b is preferably a thin plate so that it does not easily become a fluid resistance to the fluid flowing between the outer tube 10 and the inner tube 20. On the other hand, a predetermined thickness is given at the outer edge of the fin portion 31b which is a contact portion with the outer tube 10 and the inner tube 20 in order to obtain required strength and wear resistance.

  An opening 31c is formed on the side of the insertion portion 31a so that the general cylindrical portion 21 can be gripped by attaching the support member 31 from the radial direction of the inner tube 20. The opening 31c opens over a range of approximately 45 degrees in the circumferential direction. As a result, the cross section of the insertion part 31a is substantially C-shaped over the entire axial direction. The circumferential width of the opening 31c is such that the general cylindrical portion 21 of the inner tube 20 can be received in the radial direction in a state where the insertion portion 31a is deformed by applying an external force so as to expand outward in the radial direction. When the insertion portion 31a is restored to its natural state by its own elasticity, the width is such that the general cylindrical portion 21 cannot be detached in the radial direction. Therefore, the insertion part 31a is wound around the outer side of the inner tube 20 by its elasticity.

  The outer surface 31d formed at the edge facing the radially outer side of the fin portion 31b is formed in a shape along the inner peripheral surface 13a of the reduced diameter portion 13 of the outer tube 10, and the support member 31 is reduced in diameter ( It is prevented from entering the inside of the outer tube 10 along the axis by engaging with the step portion 13. The outer side surface 31d is in contact with the inner surface of the outer tube 10 from the enlarged diameter portion 12 to the reduced diameter portion 13 and the general cylindrical portion 11 in the radial direction, and provides an outer surface that is positioned in the radial direction. A depth side end surface is provided which contacts the reduced diameter portion 13 from the axially outer opening of the outer tube 10 toward the back side in the axial direction and is positioned in the axial direction. Each outer surface 31d is also an end surface facing toward the back side of the outer tube 10, and when the reduced diameter portion 13 provides a tapered surface having a larger angle, it provides an end surface along the tapered surface. In other words, the outer surface 31 d provides an end surface that abuts against the step portion of the outer tube 10 from the outer side in the axial direction of the outer tube 10 toward the inner side in the axial direction.

  Further, the inner side surface 31 e formed at the radially inner edge of the fin portion 31 b is formed in a shape along the outer peripheral surface 23 a of the bulging portion 23 of the inner tube 20. On the edge extending radially inward from the inner side surface 31e of the fin portion 31b, a vertical end surface 31f facing the end opposite to the outer side surface 31d is formed continuously with the end surface of the insertion portion 31a. Yes. These end surfaces 31f and the like engage with the bulging portion 23 of the inner tube 20 to prevent the support member 31 from moving toward the end of the inner tube 20 along the axis and coming off. These end surfaces 31f and the like are also end surfaces facing toward the end side (the axially outer side) of the inner tube 20. When the inner tube 20 is to move into the outer tube 10, these end surfaces 31 f and the like receive the bulging portion 23 by the end surface 31 f and the outer surface 31 d of the support member 31 against the reduced diameter portion 13. By contacting, the inner tube 20 is prevented from entering the outer tube 10.

  That is, the support member 31 is formed inside the outer tube 10 and has a stepped portion (reduced diameter portion 13) that increases its inner diameter toward the end portion, and is formed outside the inner tube 20 and its outer diameter faces the end portion. The inner tube 20 is supported between the outer tube 10 and the inner tube 20 from entering the outer tube 10. is doing.

  In this structure, the female side pipe joint is provided by the enlarged diameter portion 12 formed at the end of the outer tube 10. Further, a male pipe joint is provided by the seal groove portion 22 and the bulging portion 23 formed at the end of the inner pipe 20. The double pipe can be connected to a joint member having a joint shape that can be connected to the male and female pipe joints. For example, it is possible to connect to a joint member in which a female side joint is disposed inside and a male side joint is disposed concentrically therewith. Moreover, it can also be connected with the double pipe of embodiment mentioned later.

  The outer tube 10 and the inner tube 20 can provide a joint structure at the end opposite to the end illustrated in FIG. Further, at the opposite end, the inner tube 20 can be taken out through the wall surface of the outer tube 20, and the joint of the outer tube 10 and the joint of the inner tube 20 can be configured separately. In these cases, the outer tube 10 can be welded to other piping, and the inner tube 20 can also be welded to other piping. Furthermore, a joint structure according to an embodiment described later can be employed at the opposite end.

[Second Embodiment]
As shown in FIG. 2, the double pipe 2 according to the second embodiment includes an outer pipe 10 having one end formed in a male joint shape, and a female joint having one end inserted into the outer pipe 10. The inner tube 20 is formed in the outer tube 10, and the support member 32 that supports the inner tube 20 is provided in the outer tube 10.

  In the outer tube 10, a seal groove portion 14 having a diameter smaller than the outer diameter of the general tube portion 11 and a bulging portion 15 protruding in the radial direction from the general tube portion 12 are formed in the circumferential direction in this order from the terminal side. In the outer tube 10, the seal groove portion 14 is a stepped portion. An O-ring 50 is attached to the seal groove 14. The seal groove portion 14 projects toward the inner side of the outer tube 10 and provides a step portion that expands the inner diameter toward the end portion of the outer tube 10.

  Further, the inner tube 20 has an enlarged diameter portion 24 that is larger than the outer diameter of the general cylindrical portion 21, and a reduced diameter portion 25 that is reduced in diameter to the general cylindrical portion 21 following the enlarged diameter portion 24. The reduced diameter portion 25 is a stepped portion between the large diameter portion 24 and the general cylindrical portion 21.

  As shown in FIG. 2B, the support member 32 includes an insertion portion 32a through which the inner tube 20 is inserted, and a plurality of (four in FIG. 2B) fin portions 32b that abut against the seal groove portion 14 of the outer tube 10. And are integrally formed. An opening 32c is formed in the insertion portion 32a so that the general cylindrical portion 21 can be clamped by attaching the support member 32 from the radial direction of the inner tube 20. The outer surface 32d of the fin portion 32b is formed in a shape along the inner surface 14a extending from the outermost end portion of the outer tube 10 to the seal groove portion 14, and the support member 32 engages with the seal groove portion (stepped portion) 14 to be in the axis line. This prevents entry to the inside of the outer tube 10 along the line.

  In addition, the inner side surface 32e of the fin portion 32b is formed in a shape along the outer peripheral surface 25a of the reduced diameter portion 25 of the inner tube 20, and the reduced diameter portion 25 of the inner tube 20 engages with the support member 30 to make an axis line. And entering the inside of the outer tube 10 along the line.

  That is, the support member 30 is mounted between the step portion (seal groove portion 14) of the outer tube 10 and the step portion (reduced diameter portion 25) of the inner tube 20, and the inner tube 20 is attached to the axial center portion of the outer tube 10. The inner tube 20 is prevented from proceeding to the inside of the outer tube 10 while being supported.

  Similarly to the support member 31 described in the first embodiment, the support member 32 of the second embodiment is directed from the outer side in the axial direction of the outer tube 20 toward the rear side in the axial direction toward the stepped portion of the outer tube 20. The abutting engagement from the outer side (back end surface) 32d of the fin part 32b as the part to be abutted and engaged toward the stepped part of the inner pipe 10 from the inner side of the inner pipe toward the outer side in the axial direction. The insertion part 32a and the end surface (outer end surface) of the fin part 32b are provided.

  By the way, the first double pipe 101 having one end having the first embodiment and the second double pipe 202 having one end having the second embodiment can be connected as shown in FIG. It is possible to provide a piping structure including the double pipe 101 of the first embodiment and the double pipe 202 of the second embodiment. However, the first double pipe 101 is fitted into a fixing member 100 indicated by a chain line, and the second double pipe 202 is fitted into a fixing member 200 indicated by a chain line.

  That is, by moving the second double pipe 202 to the first double pipe 101 side, the outer pipe (male side joint portion) 210 of the second double pipe 202 is moved to the first double pipe 101 side. The inner pipe (male side joint part) 120 of the first double pipe 101 is inserted into the outer pipe (female side joint part) 110 and the inner pipe (female side) of the second double pipe 202 is inserted. The first double pipe is fitted into the joint portion 220 and the end of the enlarged diameter portion 112 or 225 of the female joint portion comes into contact with the bulging portion 215 or 123 of the male joint portion. The connection between 101 and the second double pipe 202 is completed. Further, the first fixing member 100 and the second fixing member 200 are fixed to a predetermined position such as a vehicle body with a bolt or the like.

  In addition, when such a double pipe is applied to a refrigeration cycle such as a vehicle air conditioner, the outer pipe 110 in the first double pipe 101 and the outer pipe 210 in the second double pipe 202 are: Since it is sealed by the O-ring 240 attached to the seal groove 214 of the outer tube 210, the low-pressure refrigerant passing through the outer tube 110 in the first double tube 101 has improved confidentiality without leaking outside. In this state, it passes through the outer tube 210 of the second double tube 202. Since the inner tube 120 of the first double tube 101 and the inner tube 210 of the second double tube 202 are sealed by the O-ring 150, the inner tube 120 of the first double tube 101 is sealed. The high-pressure refrigerant passing through the inside is supplied into the inner pipe 220 of the second double pipe 202 in a state where confidentiality is improved without leaking to the outside.

[Third Embodiment]
As shown in FIG. 3, the double pipe 3 according to the third embodiment has an outer pipe 10 having one end formed in a male joint shape, and is inserted into the outer pipe 10 and has one end formed in a male joint shape. The inner tube 20, the support member 33 that supports the inner tube 20 in the outer tube 10, and the spacer member 40 are further provided.

  The outer tube 10 is formed with a seal groove portion 14 having a diameter smaller than the outer diameter of the general cylinder portion 12 and a bulging portion 15 protruding in the radial direction from the general cylinder portion 12 in the circumferential direction in order from the terminal side. In the outer tube 10, the seal groove portion 14 is a stepped portion. An O-ring 50 is attached to the seal groove 14.

  In the inner tube 20, a seal groove portion 22 having a diameter smaller than the outer diameter of the general cylindrical portion 21 and a bulging portion 23 protruding in the radial direction from the general cylindrical portion 21 are formed in the circumferential direction in order from the terminal side. In the inner tube 20, the bulging portion 23 is a stepped portion. An O-ring 50 is attached to the seal groove portion 22.

  As shown in FIG. 3B, the support member 33 is integrally formed with an insertion portion 33 a through which the inner tube 20 is inserted and a fin portion 33 b that is in contact with the seal groove portion 14 of the outer tube 2. The insertion portion 33 a is provided with an opening 33 c so that the support member 33 can be mounted and gripped from the radial direction of the inner tube 20. The outer surface 33d of the fin portion 33b is in contact with the inner surface 14a of the outer tube 10 for positioning in the radial direction. The back end face of the fin portion 33b is formed so as to abut against and engage with the seal groove portion 14, and the support member 33 is prevented from entering the outer tube 10 along the axis.

  The space member 40 is mounted between the support member 33 and the protruding portion 23 of the protruding inner tube 20. The bulging portion 23 of the inner tube 20 engages with one end side of the spacer member 40, and the other end side of the spacer member 40 abuts against the front surface 33 e of the support member 33 so that the inner tube 20 extends along the axis of the outer tube 10. Can be prevented from entering the interior.

  That is, the support member 33 engages with the step portion (seal groove portion 14) of the outer tube 10 to support the inner tube 20 on the axial center portion of the outer tube 10, and also the step portion (the bulging portion 23) of the inner tube 20. In cooperation with the space member 40 engaged with the inner tube 20, the inner tube 20 is prevented from proceeding into the outer tube 10.

  For example, as shown in FIG. 3C, the spars member 40 is a cylinder having a C-shaped cross section having an opening 40a on its side surface, and is inserted through the inner tube 20 in the radial direction via the opening 40a. It can be fitted to the tube 20. The space member 40 has substantially the same axial cross-sectional shape as the insertion portion of the support member 33.

  The support member 33 and the spacer member 40 of the third embodiment are similar to the support members 31 and 32 described in the previous embodiment from the outside in the axial direction of the outer tube 20 toward the stepped portion of the outer tube 20. The back end face of the fin portion is provided as a portion that abuts and engages toward the back in the axial direction. Furthermore, the part which abuts and engages from the axially inner side of the inner tube toward the axially outer side toward the stepped portion of the inner tube 10 extends the end surface of the insertion portion 33a by the spacer member 40, and the spacer member 40 end faces 40b.

  The end structure of the double pipe using the support member 33 and the spacer member 40 of the third embodiment is adopted as the structure of the opposite end of the double pipe of the above-described embodiment. Can do. That is, in the structure of the third embodiment, the inner tube 20 can be moved in the axial direction by the length of the spacer member 40 before the spacer member 40 is mounted. The end structure of the double pipe described in the previous embodiment can be configured, and thereafter, the spacer member 40 can be mounted to position and fix the inner pipe 20 with respect to the outer pipe 10. For example, when manufacturing a double tube having the end shown in the first embodiment as one end and the end shown in the third embodiment as the other end, a manufacturing method having the following procedure is used. be able to.

  First, the outer tube 10 and the inner tube 20 are prepared. The inner tube 20 is longer than the outer tube 10. The step portions described in the first embodiment and the third embodiment are formed at the respective end portions of the prepared outer tube 10 and inner tube 20. By these steps, the step of preparing the outer tube 10 and the inner tube 20 is completed.

  The inner tube 20 is inserted into the outer tube 10. One end side or the other end side of the inner tube 20 is held in a state of protruding from the outer tube 10, and the support member 31 is attached to the end portion of the inner tube 20 from the radially outer side. When the support member 31 is attached to one end side, the inner tube 20 is moved in the axial direction so that the other end side of the inner tube 20 protrudes from the outer tube 10. The support member 31 may be moved in the axial direction until it contacts both the stepped portion of the outer tube 10 and the stepped portion of the inner tube 20. Then, the support member 33 is attached to the other end side of the inner tube 20. At this time, the support member 33 on the other end side does not need to be mounted at the original mounting position, but is mounted on the general cylinder portion 21 that extends long between the bulging portion 23 and the end portion of the outer tube 10. . Therefore, the support member 33 is slidable on the general tube portion 21 and the inner tube 20 is not positioned in the axial direction with respect to the outer tube 10. Next, the support member 33 on the other end side is slid and brought into contact with the step portion of the outer tube 10. As a result, on the other end side, the general cylindrical portion 21 extends long between the support member 33 and the other end side of the inner tube 20. The spacer member 40 is mounted on the general cylindrical portion 21 that protrudes and extends. The spacer member 40 corresponds to the distance between the support member 33 on the other end side and the bulging portion 23 as the stepped portion of the inner tube 20, or has a slightly shorter axial length, and supports the other end side. The gap between the member 33 and the step portion of the inner tube 20 is filled. As a result, the support member 33 and the spacer 40 are disposed between the stepped portion of the outer tube 10 and the stepped portion of the inner tube 20, and the inner tube 20 is restricted from moving toward the back side in the axial direction of the outer tube 10. It will function as a regulating member. At this time, on the other end side of the double tube, since the previously attached support member 31 is sandwiched between the two tubes, the inner tube 20 moves from one end side in the axial direction toward the other end side. This is also prevented.

  Returning to the stage where the inner tube 20 is inserted into the outer tube 10, when the support member 33 is first attached to the other end side of the inner tube 20, one end side of the inner tube 20 protrudes from the outer tube 10. The inner tube 20 is moved in the axial direction. The support member 33 may be moved in the axial direction until it contacts both the stepped portion of the outer tube 10 and the stepped portion of the inner tube 20. Then, the support member 31 is attached to one end side of the inner tube 20. At this time, the support member 33 on the other end side is not located at the original mounting position, but has moved to a position where it can come into contact with the bulging portion 23 of the inner tube 20 or the vicinity thereof. Next, the support member 33 on the other end side is slid and brought into contact with the step portion of the outer tube 10. At the same time, the inner tube 20 is pulled out to the other end side of the outer tube 10. At this time, on the one end side of the double tube, the inner tube 20 may be moved in the axial direction until the support member 31 contacts both the stepped portion of the outer tube 10 and the stepped portion of the inner tube 20. As a result, on the other end side, the general cylindrical portion 21 extends long between the support member 33 and the other end side end portion of the inner tube 20. Therefore, the support member 33 is slidable on the general tube portion 21 and the inner tube 20 is not positioned in the axial direction with respect to the outer tube 10. Next, the spacer member 40 is attached to the general cylindrical portion 21 that protrudes and extends. The spacer member 40 corresponds to the distance between the support member 33 on the other end side and the bulging portion 23 as the stepped portion of the inner tube 20, or has a slightly shorter axial length, and supports the other end side. The gap between the member 33 and the step portion of the inner tube 20 is filled. As a result, the support member 33 and the spacer 40 are disposed between the stepped portion of the outer tube 10 and the stepped portion of the inner tube 20, and the inner tube 20 is restricted from moving toward the back side in the axial direction of the outer tube 10. It will function as a regulating member. At this time, on the other end side of the double tube, since the previously attached support member 31 is sandwiched between the two tubes, the inner tube 20 moves from one end side in the axial direction toward the other end side. This is also prevented.

  As shown in FIG. 5, the double pipe 303 according to the third embodiment is equipped with a two-way branch joint 400 and a pair of pipe members (not shown) separately piped (for example, High-pressure piping and low-pressure piping) can be connected.

  A two-way branch joint 400 is attached to the outer tube 310 so as to cover the tip of the outer tube 310. The two-way branch joint 400 has a main body portion 401 that extends in a pipe shape along the axis of the double pipe 303, and a small-diameter hole that is disposed side by side in a direction orthogonal to the axis of the main body portion 401. 411 and a large-diameter hole 412 are formed.

  The outer pipe 310 of the double pipe 303 is fitted through the O-ring 350 on the inner peripheral surface at one end of the main body 401, and the distal end of the main body 401, that is, the insertion into which the double pipe 303 is inserted. The part 413 is formed to lock the bulging part 315 of the outer tube 310. The main body central portion 412 a is connected to the distal end of the outer tube 310 and is formed in a hollow shape, and is connected to a large-diameter hole 412 orthogonal to the axis of the main body portion 401.

  The other end of the main body portion 401 is formed in a thick wall portion 402 adjacent to the main body central portion 412a. A small-diameter hole 411 is formed in the thick-walled portion 402 so as to be orthogonal to the axial center of the main body 401. By inserting the tip of the inner tube 320 into the thick-walled portion 402, the small-diameter hole 411 and the inner tube 320 can be communicated.

  As a result, the double pipe 303 can communicate the inner pipe 320 and the outer pipe 310 with the small diameter hole 411 and the large diameter hole 412 of the two-way branch joint 400, respectively. By connecting and connecting the low-pressure pipe to the large-diameter hole 412, the branch pipe and the double pipe can be connected in the same refrigeration cycle.

  The two-way branch joint 400 is disposed, for example, at a joint portion with a double pipe when a double pipe is piped to an evaporator for a rear seat from a part of a pipe in a refrigeration cycle arranged in an engine room. Will be. As a result, when a long distance is piped from the engine room to the rear part of the vehicle body, the double pipe 303 can be saved, thereby saving the piping members and saving the piping space.

(Support member)
As already described, the support member of the present invention has a shape that comes into contact with the inner peripheral surface of the stepped portion formed at the end of the outer tube and the outer peripheral surface of the stepped portion formed at the end of the inner tube. Although the supporting member suitable for each double pipe shown in FIGS. 1 to 3 is illustrated in each perspective view, the shape of the supporting member is not limited to these, and the inner pipe is gripped and engaged from the radial direction. As long as it can be engaged with the stepped portion of the outer tube and the fluid in the outer tube can be circulated, the shape of the front view illustrated in FIGS.

  (A) is a C-shaped insertion portion having a C-shaped outer tube abutting portion 30g having an opening portion 30c 'abutting on the inner peripheral surface of the outer tube and an opening portion 30c abutting on the outer peripheral surface of the inner tube. 30a and the fin part 30b which connects them are continuously formed integrally, and can be attached to the inner tube via the opening 30c.

  In (b), a C-shaped inner tube insertion portion 30a having an opening 30c that contacts the outer peripheral surface of the inner tube and three fin portions 30b that contact the inner peripheral surface of the outer tube at the side surface 30d are continuous. And can be attached to the inner tube through the opening 30c.

  (C) is formed integrally by providing a flange 30h that contacts the inner peripheral surface of the outer tube at the tip of the fin portion 30b of (b), and is attached to the inner tube through the opening 30c. can do.

  (D) shows a continuous C-shaped outer tube contact portion 30g having an opening 30c 'that contacts the inner peripheral surface of the outer tube, and a fin portion 30b that contacts the outer peripheral surface of the inner tube at the side surface 30e. It is formed integrally and can be attached to the inner tube via the opening 30c ′.

  (E) includes a fin portion 30b projecting in the axial direction at the end of the opening 30c ′ in (d), and the fin portion 30b is elastically deformed to allow the inner tube to pass through. The inner tube is inserted at the tip of the fin portion 30b. By pressing in the axial direction, the relative position of the outer tube and the inner tube can be made more stable.

  (F) is formed by continuously and integrally forming an annular outer tube contact portion 30g that contacts the inner peripheral surface of the outer tube and a fin portion 30b that contacts the outer peripheral surface of the inner tube. The hollow portion 30j is sized to allow the bulging portion 23 formed at the distal end portion of the inner tube to be inserted, and the support member 30 is inserted through the hollow portion 30j from the distal end of the inner tube and is inserted into the inner tube at a predetermined position. By moving in the direction intersecting the axis so that the axis of the shaft and the axis of the support member coincide with each other, the fin portion 30b can contact the outer peripheral surface of the inner tube to support the inner tube.

  Further, the vertical cross section of the support member 30 may be as shown in FIGS.

  (G) is a support member suitable for use in a double pipe in which the end of the outer tube shown in FIG. 2 (a) has a male joint shape and the end of the inner tube has a female joint shape. The inner tube 20 is engaged only with the reduced diameter portion 25, and the parallel portion with the axis that contacts the enlarged diameter portion 24 is omitted at the fin portion 32b of the support member 32 shown in FIG. 2B.

  (H) is a support member suitable for use in a double pipe in which the end of the outer tube shown in FIG. 1 (a) has a female joint shape and the end of the inner tube has a male joint shape. The outer tube 10 is engaged only by the reduced-diameter portion 13, and a portion parallel to the axis that contacts the enlarged-diameter portion 12 is omitted at the fin portion 31 b of the support member 31 shown in FIG.

  The support member described above is an example, and various shapes can be made without departing from the spirit of the present invention.

  In the support member having the above-described shape, the curvature R1 of the inner corner portion (for example, 30k in FIG. 6G) that contacts the step portion of the outer tube, particularly the seal groove portion, is the outer angle of the inner peripheral surface of the outer tube. It is desirable that the curvature is larger than the curvature R2 (for example, FIG. 4). This is because in the case of R1 <R2, the support member may be damaged because the concentrated stress of tension acts on the inner corner portion 30k of the support member. The probability of breakage of the support member can be reduced by setting the concentrated stress of compression as R1> R2.

  Further, it is preferable that the corners of the support member exposed to the fluid flowing in the outer tube, for example, the side edge ridge lines (such as 31m in FIG. 1 (b)) of the fin portion are rounded to form a gentle curved surface. . By attaching R to these corners, it is possible to prevent the fluid flowing through the outer tube from being disturbed and to suppress the passage sound of the fluid.

  Furthermore, it is desirable that the outer dimension of the support member that comes into contact with the outer tube is a size that can absorb the deviation of the coaxial degree of the end machining portion between the outer tube and the inner tube. Specifically, a slight gap is provided between the outer peripheral portion of the support member and the inner peripheral surface of the outer tube in consideration of the deviation of the coaxiality. This makes it possible to reliably and easily connect the double pipes or the double pipe and the two-way branch joint.

  As described above, the support member positioned at the end of the double tube is preferably formed using a resin material having high strength and easy elastic deformation, such as nylon or PPS. The support member made of a resin material having high strength and elastically deformable is lightweight and can be mounted so as to grip the inner tube from the radial direction, thereby improving the productivity of the double tube. it can.

  In the double pipe of the present invention, a support member can be provided at an intermediate portion in the longitudinal direction in order to prevent abnormal noise and wear caused by vibration of the inner pipe. In particular, it is desirable that the bent portion of the double tube is provided with a support member along the bent shape.

  Such a support member (referred to as an intermediate support member 35) has a small annular portion 35a inserted through the inner tube as shown in FIG. 7 (a), and outwards from the outer peripheral surface of the small annular portion 35a at equal intervals. Are integrally formed with a plurality of fin portions 35b extending toward the inner surface and a large annular portion 35g that abuts on the inner peripheral surface of the outer tube, as shown in FIG. It is inserted and placed inside the outer tube 10.

  The intermediate support member 35 protrudes in a spiral shape as shown in (b) even when the fin portion 35b protruding from the small annular portion 35a does not protrude in the radial direction of the small annular portion 35a. It may be continuous with the ring portion 35g. Further, as shown in (c) and (d), the configuration may be such that the large annular portion is omitted and the tip side surface 35d of the fin portion 35b directly contacts the inner peripheral surface of the outer tube.

  FIGS. 7A to 7D show examples of the cross-sectional shape of the intermediate support member 35. If the inner tube can be stably supported by the axis inside the outer tube, the shape of the intermediate support member is as follows. Any selection may be made.

  In addition, when such an intermediate support member 35 is disposed in a bent portion of a double tube, it is desirable to form the intermediate support member 35 with a material that does not buckle so as to withstand bending. 8A to 8C are schematic views illustrating the intermediate support member 35 in the bent portion. As shown in these examples, the intermediate support member 35 can be greatly deformed in the bent portion. For example, when the intermediate support member 35 is made of a resin having a small material elongation, the intermediate support member 35 is reduced as the bending cross section of the outer tube 10 decreases. 35 is compressed and buckled. Therefore, it is preferable to use a metal material such as aluminum or copper having a large material elongation and high buckling resistance.

(Production method)
The double tube having the support member as described above can be manufactured as follows.

  The double pipe manufacturing method includes a stepped portion forming step for forming stepped portions at both ends of the inner tube and the outer tube, and a support member that supports the inner tube and engages the stepped portion of the outer tube. A support member mounting step for fixing the inner tube in the outer tube, and a spacer member mounting step for mounting the support member on the other end and mounting the spacer member on the protruding portion of the inner tube to fix the inner tube in the axial direction. It is characterized by.

  That is, first, step portions are formed at both ends of the inner tube and the outer tube (step portion forming step), and the step portion of the inner tube is formed on one end side of the inner tube with respect to the outer tube and the inner tube formed with the step portion. The support member is attached to the inner tube from the radial direction of the inner tube so as to abut against the inner tube, the inner tube to which the support member is attached is advanced into the outer tube, and the support member is locked at the step portion of the outer tube. (Support member mounting step).

  Next, a support member is similarly attached to the other end side of the inner tube, and the support member is moved in the axial direction to the inside of the outer tube and locked to the step portion of the outer tube. Thereafter, a spacer member that abuts on the inner tube protruding from the surface of the supporting member and abuts on the bulging portion of the inner tube and suppresses the axial movement of the inner tube from the radial direction of the inner tube. Mounting and fixing (spacer member mounting step). In this way, a double pipe having the joint shape shown in FIG. 1 (a) or FIG. 2 (a) at one end and the joint shape shown in FIG. 3 (a) at the other end can be obtained. That is, according to this double pipe manufacturing method, a double pipe having a joint structure at both ends can be manufactured with a simple assembling process and a reliable connection structure. Moreover, the joint structure of one end can be made into the joint shape connected with connectors, such as a two-way branch joint.

  The double pipe can be obtained by the above method, but in the case of a double pipe having a long straight part or a bent part, a step of incorporating an intermediate support member as follows: Bending the double tube. That is, it is a manufacturing method including an assembling process → stepped portion forming process → support member mounting process → spacer member mounting process → bending process.

  First, as an assembling step, the intermediate support member 35 is inserted into the inner tube, and the intermediate support member 35 is fixed (temporarily fixed) at a predetermined position. The fixing means may use an adhesive, or may be caulked. Subsequently, the inner tube inserted through the intermediate support member is inserted into the outer tube. Next, in the stepped portion forming step, one end side of the outer tube is formed into the shape of the outer tube 10 in FIG. 1A or 2A, and the other end is formed in the shape of the outer tube 10 in FIG. To form. When the formation of the outer tube end portion is completed, both end portions of the inner tube are formed with reference to the end of the outer tube. For example, when the outer tube and the inner tube at one end (referred to as end portion A) are formed into the shape of FIG. 1A, the outer tube and the inner tube at the other end (referred to as end portion B) are shown in FIG. ).

  Next, in the support member mounting step, first, the support member 31 is mounted so as to be engaged with the bulging portion 23 of the inner tube 20 at the end A, and the support member 31 is caused to enter the outer tube 10 to be inserted into the outer tube. The stepped portion 13 is locked.

  Subsequently, in the spacer member mounting step, the support member 33 is inserted into the inner tube 20 protruding from the end B, and is brought into contact with the seal groove 14 of the outer tube 10 to be locked. Since the inner tube 20 at the end B protrudes in the axial direction from the surface of the support member 33, the spacer member 40 having a length from the surface of the support member 33 to the bulging portion 23 of the inner tube 20 is protruded from the inner tube 20. Attach to the part.

  Thus, at the end A, the inner tube 20 is fixed in the outer tube 10 by the support member 31, and at the end B, the inner tube 20 is fixed in a state of protruding from the outer tube 10 by the support member 33 and the spacer member 40. The

  Furthermore, a desired double pipe can be obtained by performing a predetermined bending process at the insertion position of the intermediate support member 35 in the bending step.

  The double pipe of the present invention is suitable as a pipe for a refrigeration cycle constituting a vehicle air conditioner in which a high-pressure refrigerant is circulated through an inner pipe and a low-pressure refrigerant is circulated through an outer pipe. Furthermore, the present invention can also be applied to an air conditioner arranged in a structure such as a building.

(A) It is a cross-sectional schematic diagram of the edge part of the double tube which shows the 1st form of this invention. (B) It is a perspective view which shows an example of a suitable supporting member used for (a). (A) It is a cross-sectional schematic diagram of the edge part of the double tube which shows the 2nd form of this invention. (B) It is a perspective view which shows an example of a suitable supporting member used for (a). (A) It is a cross-sectional schematic diagram of the edge part of the double tube which shows the 3rd form of this invention. (B) It is a perspective view which shows an example of a suitable supporting member used for (a). (C) It is a perspective view which shows an example of a suitable spacer member used for (a). It is a cross-sectional schematic diagram explaining the state which connected the double pipe of the 1st form and the double pipe of the 2nd form. It is a cross-sectional schematic diagram explaining the state which connected the double pipe of the 3rd form to the two-way branch joint. It is a schematic diagram which illustrates the shape of a supporting member. (A)-(c) is a front view schematic diagram of what has a C-shaped ring part contact | abutted to the outer peripheral surface of an inner tube | pipe. (D)-(f) is a front view schematic diagram of what has a C-shaped annular part which contacts the inner peripheral surface of an outer tube | pipe, or an annular part. (G) and (f) are examples of cross-sectional shapes. It is a schematic diagram which illustrates the shape of an intermediate support member. (A), (b) is a cross-sectional schematic diagram of what has an annular part which contact | abuts to the internal peripheral surface of an outer tube | pipe. (C), (d) is a cross-sectional schematic diagram of what does not have a ring part which contact | abuts to the internal peripheral surface of an outer tube | pipe. (E) is explanatory drawing explaining the mounting state of an intermediate | middle support member. It is a schematic diagram which illustrates the state of the intermediate support member in a bending part. The shape of the intermediate support member is different between (a), (b), and (c).

Explanation of symbols

1, 2, 3: Double pipe 10: Outer pipe (second pipe) 12: Outer pipe diameter-expanded section 13: Outer pipe diameter-reduced section (stepped section) 14: Outer pipe seal groove section (stepped section) 15: Outer pipe Swelling part 20: Inner pipe (first pipe) 22: Inner pipe seal groove part 23: Inner pipe bulging part (step part) 24: Inner pipe diameter-enlarged part 25: Inner pipe diameter-reduced part (step part) 30 (31 32, 33): Support member 30a: Inner tube support portion (insertion portion) 30b: Fin portion 30c: Opening portion 40: Spacer member 40a: Opening portion 50: O-ring 100: First double tube fixing member 200: Second double pipe fixing member 400: Two-way branch joint

Claims (15)

A double pipe having a first pipe having a small diameter and a second pipe having a diameter larger than that of the first pipe, wherein the first pipe is disposed in the second pipe;
It has a supporting member that contacts the outer peripheral surface of the first pipe and supports the first pipe at a predetermined position in the second pipe by contacting the inner peripheral surface of the second pipe. Double tube.   2. The double pipe according to claim 1, wherein the support member is located on an axially outer side of a step portion formed at an end portion of the second pipe and is engaged with the step portion.   3. The double pipe according to claim 2, wherein the support member is located on an inner side in an axial direction of a step portion formed at an end portion of the first pipe and is engaged with the step portion.   The double pipe according to claim 3, further comprising a spacer member between the support member and a step portion at the end of the first pipe.   The double pipe according to claim 4, wherein the support member is provided at both ends, and the support member and the spacer member are provided only at one end side.   2. The double pipe according to claim 1, wherein the support member is positioned at an intermediate portion in an axial direction of the second pipe and supports the first pipe.   The double pipe according to claim 6, wherein the support member is located at a bent portion of the second pipe.   The double tube according to any one of claims 1 to 7, wherein the support member is made of a metal such as aluminum, or a resin such as nylon or PPS.   The double pipe according to any one of claims 1 to 8, wherein the double pipe is a pipe connecting components of a refrigeration cycle, and a refrigerant flows therein. A method for producing a double pipe having a first pipe having a small diameter and a second pipe having a diameter larger than that of the first pipe, wherein the first pipe is disposed in the second pipe;
A stepped portion forming step of forming a stepped portion at both ends of each of the first pipe and the second pipe;
A support member mounting step of fixing the first pipe in the second pipe with a support member that supports the first pipe and engages a step portion of the second pipe;
And a first pipe fixing step of fixing the first pipe in the axial direction by mounting the support member on the other end and mounting a spacer member on the projecting portion of the first pipe. Production method. An assembling step of incorporating the first pipe into which the support member for supporting the first pipe is mounted at the intermediate portion in the axial direction of the second pipe into the second pipe;
The method for manufacturing a double pipe according to claim 10, further comprising a bending step of bending the first pipe and the second pipe at a predetermined angle together with the support member attached to the first pipe.   The method for manufacturing a double pipe according to claim 11, wherein the support member is temporarily fixed to the first pipe with an adhesive or caulking. A double pipe support member in which a first pipe having a small diameter is disposed in a second pipe having a diameter larger than that of the first pipe,
The double pipe support member is located between the step portion of the first pipe and the step portion of the second pipe and supports the first pipe at a predetermined position of the second pipe.   A first pipe support portion that supports the first pipe; and a plurality of fin portions that protrude from an outer periphery of the first pipe support portion, and the first pipe is radially disposed on a side portion of the first pipe support portion. The support member for a double pipe according to claim 13, further comprising an opening inserted into the tube.   The double pipe support member according to claim 13 or 14, wherein the double pipe is a pipe connecting components of a refrigeration cycle, wherein the refrigerant flows therein, and the support member is disposed in the refrigerant.

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