WO2017038962A1 - Method for manufacturing double pipe - Google Patents

Method for manufacturing double pipe Download PDF

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Publication number
WO2017038962A1
WO2017038962A1 PCT/JP2016/075757 JP2016075757W WO2017038962A1 WO 2017038962 A1 WO2017038962 A1 WO 2017038962A1 JP 2016075757 W JP2016075757 W JP 2016075757W WO 2017038962 A1 WO2017038962 A1 WO 2017038962A1
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WO
WIPO (PCT)
Prior art keywords
pipe
tube
outer tube
inner tube
double
Prior art date
Application number
PCT/JP2016/075757
Other languages
French (fr)
Japanese (ja)
Inventor
飯島　健次
林　直人
Original Assignee
株式会社ヴァレオジャパン
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 株式会社ヴァレオジャパン filed Critical 株式会社ヴァレオジャパン
Publication of WO2017038962A1 publication Critical patent/WO2017038962A1/en

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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21D53/00—Making other particular articles
    • B21D53/02—Making other particular articles heat exchangers or parts thereof, e.g. radiators, condensers fins, headers
    • B21D53/06—Making other particular articles heat exchangers or parts thereof, e.g. radiators, condensers fins, headers of metal tubes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60H—ARRANGEMENTS OF HEATING, COOLING, VENTILATING OR OTHER AIR-TREATING DEVICES SPECIALLY ADAPTED FOR PASSENGER OR GOODS SPACES OF VEHICLES
    • B60H1/00—Heating, cooling or ventilating [HVAC] devices
    • B60H1/22—Heating, cooling or ventilating [HVAC] devices the heat being derived otherwise than from the propulsion plant
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28D—HEAT-EXCHANGE APPARATUS, NOT PROVIDED FOR IN ANOTHER SUBCLASS, IN WHICH THE HEAT-EXCHANGE MEDIA DO NOT COME INTO DIRECT CONTACT
    • F28D7/00—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall
    • F28D7/10—Heat-exchange apparatus having stationary tubular conduit assemblies for both heat-exchange media, the media being in contact with different sides of a conduit wall the conduits being arranged one within the other, e.g. concentrically
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
    • F28F21/08—Constructions of heat-exchange apparatus characterised by the selection of particular materials of metal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/14—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally
    • F28F1/16—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending longitudinally the means being integral with the element, e.g. formed by extrusion
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F1/00—Tubular elements; Assemblies of tubular elements
    • F28F1/10—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses
    • F28F1/12—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element
    • F28F1/34—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending obliquely
    • F28F1/36—Tubular elements and assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with projections, with recesses the means being only outside the tubular element and extending obliquely the means being helically wound fins or wire spirals

Definitions

  • the present invention relates to a method for easily manufacturing a double pipe used as an internal heat exchanger of a refrigeration cycle mounted on a vehicle.
  • Patent Document 1 In order to improve the refrigeration efficiency of the refrigeration cycle, for example, a double pipe disclosed in Patent Document 1, Patent Document 2, etc. is used as an internal heat exchanger for exchanging heat between the medium on the high pressure side and the medium on the low pressure side. Is known.
  • These double pipes disclosed in Patent Document 1 and Patent Document 2 include a first medium that includes an outer pipe and an inner pipe inserted into the outer pipe, and flows between the outer pipe and the inner pipe. And a heat exchange between the second medium flowing through the inner pipe.
  • the double pipe has a gap through which the first medium flows between the outer pipe and the inner pipe, when the vibration of the vehicle is transmitted to the double pipe, the outer pipe and the inner pipe May vibrate and the outer tube and the inner tube come into contact with each other, generating abnormal noise and damaging the outer tube and the inner tube.
  • the double pipe is configured to have a straight pipe part and bent parts arranged on both sides of the straight pipe part.
  • the outer surface (outer circumference) of the inner pipe does not contact the inner surface (inner circumference) of the outer pipe, or the outer surface of the inner pipe contacts only one of the inner surfaces of the outer pipe, while in the bent part, the outer surface of the inner pipe And the inner surface of the outer tube are in contact in a plurality of radial directions.
  • the double pipe disclosed in Patent Document 2 is provided with a spiral concavo-convex part in the straight pipe part of the inner pipe, and the convex part of the convex concave part is the inner surface of the outer pipe. It is the structure which contact
  • An outline of the manufacturing method of the double pipe of Patent Document 1 will be described.
  • An insertion process for inserting an inner pipe formed with a spiral groove into an outer pipe is performed, and then a bending process for bending the inner pipe and the outer pipe at the same time is performed.
  • the bent portion is formed by performing the operation, and the inner tube is brought into contact with the outer tube at a plurality of positions only at the formed bent portion.
  • the outer tube and the inner tube are fixed in the bending portion, but the outer tube and the inner tube are not fixed in the vicinity of the bending portion in the straight tube portion.
  • the inner surface of the outer tube and the outer surface of the inner tube are close to each other, and there is a risk of contact when vibration is transmitted to the double tube.
  • the distance between one bent part and the other bent part is long (the dimension of the straight pipe part is long in the extending direction of the pipe)
  • the outer pipe and the inner pipe May be bent, and the inner surface of the outer tube may come into contact with the outer surface of the inner tube.
  • the degree of freedom in design of the double pipe is significantly limited.
  • the double pipe disclosed in Patent Document 2 is inserted into the outer pipe so that the convex part of the inner pipe in which the spiral convex concave part is formed is in contact with the inner surface of the outer pipe that is a straight pipe. Therefore, it is foreseen that when the vibration from the vehicle is transmitted, the generation of noise in the straight pipe portion and the damage of the inner pipe and the outer pipe are prevented.
  • the outer tube and the inner tube are not fixed at the bent portion, and the outer tube and the inner tube may be bent, and the inner surface of the outer tube and the outer surface of the inner tube may come into contact with each other. In particular, the larger the bend R of the bent portion, the higher the risk of contact.
  • Patent Document 2 how to fix the inner pipe in which the spiral convex and concave portions are formed in advance to the inner surface of the outer pipe is two.
  • the fixing process of the manufacturing method of a heavy pipe is not disclosed.
  • an object of the present invention is to provide a method of manufacturing a double tube that can fix an outer tube and an inner tube regardless of the presence or absence of a bending portion and can easily manufacture a double tube having high vibration resistance. Yes.
  • a manufacturing method of a double pipe according to the present invention is a manufacturing method of a double pipe used as an internal heat exchanger of a refrigeration cycle mounted on a vehicle, and the outer pipe has an outer diameter that is larger than the inner diameter of the outer pipe.
  • An insertion step of inserting a small inner tube, and a step performed after the insertion step, in which a part of the outer tube is recessed until it comes into contact with the outer periphery of the inner tube, and the outer tube and the inner tube are And a fixing step for fixing.
  • the medium that flows between the inner tube and the outer tube is the first medium
  • the medium that flows in the inner tube is the second medium.
  • These media are, for example, refrigerants.
  • a step of inserting an inner tube having an outer diameter smaller than the inner diameter of the outer tube into the outer tube, and a part of the outer tube with the inner tube inserted therein are recessed, and Since the outer tube and the inner tube are fixed by the step of contacting the tube, the outer tube and the inner tube can be easily fixed regardless of the presence or absence of the bent portion.
  • the fixing step is a step of denting the outer pipe along the extending direction of the outer pipe.
  • the outer tube is recessed from a certain direction, the step of rotating the outer tube or the jig becomes unnecessary, and thus the double tube can be easily manufactured.
  • the fixing step is a step of denting the outer pipe so that a plurality of bottomed holes are scattered.
  • the fixing step is a step of recessing the outer tube in a spiral shape.
  • the number of spiral dents may be one or two or more.
  • the first medium flowing between the outer tube and the inner tube is caused to flow spirally using the spiral recess formed in the outer tube as a guide, and the second medium flows through the inner tube.
  • a double tube with improved heat exchange rate with the medium can be provided by an easy manufacturing method.
  • the top surface of the portion of the outer pipe that is helically recessed is It is a process of continuously contacting the inner pipe.
  • the top surface of the spirally recessed portion of the outer tube continuously contacts the inner tube, so that the first medium flowing between the outer tube and the inner tube is an extension of the double tube. Since a short circuit in the direction is prevented and the spiral flow is ensured, the heat exchange rate with the second medium flowing through the inner tube can be easily improved.
  • the inner pipe has a recess whose outer periphery is recessed spirally.
  • the first medium flowing between the outer tube and the inner tube is spirally passed through the inner tube through the inner tube, with the outer periphery of the inner tube serving as a guide.
  • a double tube with an improved heat exchange rate with the second medium can be provided by an easy manufacturing method.
  • the outer pipe in which the inner pipe is inserted is bent to a predetermined angle, or A bending process for bending is provided, and the fixing step is performed on a portion of the outer tube that is bent or bent by the bending process.
  • the fixing step causes the part of the outer pipe to be recessed until a part of the outer pipe reaches the inner side of the outer periphery of the inner pipe. It is a process.
  • the outer tube and the inner tube are fitted by being recessed until a part of the outer tube reaches the inner side of the outer periphery of the inner tube.
  • the outer tube and the inner tube can be easily and firmly fixed.
  • the outer pipe and the inner pipe are made of aluminum.
  • the step of inserting an inner tube having an outer diameter smaller than the inner diameter of the outer tube into the outer tube, and a part of the outer tube with the inner tube inserted therein The outer tube and the inner tube are fixed by the step of making the dent and the inner tube are brought into contact with the inner tube, so that the outer tube and the inner tube can be easily fixed regardless of the presence or absence of the bent portion. be able to.
  • FIG. 1 is a schematic view of a refrigeration cycle provided with a double pipe as an internal heat exchanger.
  • 2A and 2B are explanatory views showing an outline of the double tube in Example 1.
  • FIG. 2A is a perspective view of the double tube
  • FIG. 2B is a cross-sectional view of the double tube.
  • 3A is an enlarged view of the cross-sectional view taken along the line AA in FIG. 2B
  • FIG. 3B is an enlarged view of the cross-sectional view taken along the line BB of FIG. 2B.
  • 4A and 4B are explanatory views showing an outline of a double tube in Example 2.
  • FIG. 4A is a perspective view of the double tube
  • FIG. 4B is a cross-sectional view of the double tube. .
  • FIG. 5A is an enlarged view of the cross-sectional view taken along the line CC of FIG. 4B
  • FIG. 5B is an enlarged view of the cross-sectional view taken along the line DD of FIG. 4B.
  • 6A and 6B are explanatory views showing an outline of a double tube in Example 3.
  • FIG. 6A is a perspective view of the double tube
  • FIG. 6B is a cross-sectional view of the double tube.
  • Fig. 6 (c) is a cross-sectional view of a double pipe, and shows an embodiment using an inner tube having a dent whose outer periphery is spirally recessed.
  • Show. 7A is an enlarged view of the cross-sectional view taken along the line EE of FIG. 6B, and FIG.
  • FIG. 7B is an enlarged view of the cross-sectional view taken along the line FF of FIG. 6C.
  • 8A and 8B are explanatory views showing an outline of a double pipe according to a modification of the third embodiment.
  • FIG. 8A is a perspective view of the double pipe, and FIG. It is sectional drawing.
  • FIG. 9 is a cross-sectional view showing a mode in which a fixing process is performed after bending based on the dent of Example 2, FIG. 9 (a) shows a state before the fixing process, and FIG. 9 (b) shows a fixing process. It shows after the process.
  • FIG. 10 is a cross-sectional view showing a double tube after a step of denting a part of the inner surface of the outer tube to the inside of the outer periphery of the inner tube in the fixing step as a modification of the second embodiment.
  • FIG. 1 shows an example of a refrigeration cycle 1 having a double pipe 7 described below.
  • the refrigeration cycle 1 is mounted on a vehicle and constitutes a part of a vehicle air conditioner (not shown).
  • the refrigeration cycle 1 includes a compressor 2 that compresses the refrigerant, a radiator 3 that cools the refrigerant compressed by the compressor 2, and an expansion device that expands the refrigerant cooled by the radiator 3 by decompressing the refrigerant.
  • an evaporator 5 that evaporates the refrigerant decompressed by the expansion device 4
  • an accumulator that separates the refrigerant flowing out of the evaporator 5 into a gas layer and a liquid layer and sends the refrigerant in the gas layer to the compressor 2 6 and a double pipe 7 used as an internal heat exchanger for exchanging heat between the low-pressure refrigerant led from the accumulator 6 to the compressor 2 and the high-pressure refrigerant led from the radiator 3 to the expansion device 4.
  • the evaporator 5 and the accumulator 6, the pipe through which the low-pressure refrigerant flows through the accumulator 6 and the double pipe 7, and the pipe through which the low-pressure refrigerant flows through the double pipe 7 and the compressor 2 are appropriately connected via the pipe 8. It is connected.
  • a portion of the pipe 8 from the discharge port of the compressor 2 to the inlet of the expansion device 4 forms a high-pressure side piping portion 8A, and of the pipe 8, the outlet from the expansion device 4 to the suction port of the compressor 2.
  • part has comprised the low voltage
  • FIGS. 4 and 5 show the second embodiment of the present invention
  • FIGS. 6 to 8 show the embodiment of the present invention.
  • Example 3 and its variations are shown.
  • the first embodiment, the second embodiment, the third embodiment, and modifications thereof will be described.
  • the double pipe 7 of the first embodiment has an aluminum inner pipe 11 and an outer pipe 12, and the inner pipe 11 is inserted into the outer pipe 12.
  • the double pipe 7 may have a straight pipe portion 7A (FIG. 2) and a bent portion 7B (FIG. 9).
  • FIG.2 and FIG.3 shows, the inner tube
  • the outer periphery may have a dent that is spirally recessed.
  • the inner pipe 11 is connected to the low-pressure side pipe portion 8B on both sides in the extending direction
  • the outer pipe 12 is connected to the high-pressure side via holes 12a formed on the outer surfaces near both ends in the extending direction. It is connected to the piping part 8A.
  • the connection method is not particularly limited as long as the inner pipe 11 is connected to the low-pressure side piping part 8B and the outer pipe 12 is connected to the high-pressure side piping part 8A.
  • both sides of the outer tube 12 in the extending direction are closed by the inner tube 11, but if the refrigerant does not leak from both ends in the extending direction of the outer tube 12, the outer tube 12.
  • the method of closing both sides in the extending direction is not particularly limited.
  • the low-pressure refrigerant (second medium) flows through the inner pipe 11 of the double pipe 7 and the high-pressure refrigerant (first medium) flows between the outer pipe 12 and the inner pipe 11, Heat can be exchanged between the low-pressure refrigerant and the high-pressure refrigerant.
  • the inner tube 11 and the outer tube 12 of the double tube 7 are fixed by the following manufacturing method.
  • a method of manufacturing the double pipe 7, in particular, a fixing process for fixing the inner pipe 11 and the outer pipe 12 by forming the recess 21 in the outer pipe 12 will be described below with reference to FIGS. 2 and 3.
  • the inner tube 11 having an outer diameter smaller than the inner diameter of the outer tube 12 is inserted into the outer tube 12.
  • the dent forming tool 50 in which the rotating plate 52 is rotatably supported by the shaft portion 51 is moved upward with respect to the outer tube 12 in which the inner tube 11 is inserted. Then, a part of the outer tube 12 is further pushed into the inner tube 11. Then, the rotary plate 52 is pushed and moved along the extending direction of the outer tube 12.
  • the inner tube 11 is further pushed, and the inner tube 11 is pressed against the inner surface of the outer tube 12 opposite to the recess 21. Until the outer surface comes into contact, a part of the outer tube 12 is recessed with the rotating plate 52 of the recess forming device 50.
  • a recess 21 extending linearly along the extending direction of the outer tube 12 is formed above the outer tube 12, and the top surface 21a of the recess 21 and the outer tube Of the inner surface of 12, the opposite side of the recess 21 (below the inner surface of the outer tube 12) is in continuous contact with the outer surface of the inner tube 11 along the extending direction of the pipe. Therefore, at least in the straight pipe portion 7A of the double pipe 7, the inner pipe 11 is sandwiched from above and below between the top surface 21a of the recess 21 of the outer pipe 12 and the inner surface opposite to the recess 21 of the outer pipe 12. Therefore, it is fixed to the outer tube 12.
  • the insertion of the inner tube 11 into the outer tube 12 inserts the inner tube 11 having an inner diameter smaller than the inner diameter of the outer tube 12, so that the insertion process can be smoothly performed. Since the inner tube 11 and the outer tube 12 can be fixed by the fixing step for forming the recess 21, the double tube 7 can be easily manufactured. In addition, the inner tube 11 and the outer tube 12 can be fixed by the straight tube portion 7A of the double tube 7 regardless of the presence or absence of the bent portion.
  • the present invention is not limited to the step of forming the recess 21.
  • the recess 21 may be formed by indenting from a diagonally upper side, from the side, or from the lower side using a device such as the recess forming device 50.
  • the inner tube 11 is fixed to the outer tube 12 in contact with the top surfaces 21 a and 21 a of the plurality of recesses 21.
  • the double pipe 7 of the second embodiment has an inner pipe 11 and an outer pipe 12 made of aluminum, a straight pipe portion 7 ⁇ / b> A (FIG. 2), and a bent portion 7 ⁇ / b> B.
  • the inner tube 11 may have a circular shape on the outer periphery of the inner tube 11 or the outer periphery of the inner tube 11 or may be the following FIG. 6 (c), FIG. 7 (b), FIG.
  • the outer tube 12 may be connected to the low-pressure side piping portion 8B, and the outer tube 12 may be connected to the high-pressure side piping portion 8A. It is common with the double pipe 7 of Example 1 by the point which was made the structure. Therefore, about the structure and function similar to the double tube 7 of Example 1 among the double tubes 7 of Example 2, the description is abbreviate
  • the manufacturing method of the double pipe 7 of Example 2 also includes an insertion process and a fixing process.
  • the insertion process is the same as that of the first embodiment, but the fixing process is different from that of the first embodiment.
  • the manufacturing method of this double pipe 7, especially the fixing process different from the fixing process of the double pipe 7 of Example 1 is demonstrated below using FIG.4 and FIG.5.
  • the inner tube 11 having an outer diameter smaller than the inner diameter of the outer tube 12 is inserted into the outer tube 12.
  • a dent forming tool (not shown) suitable for forming a bottomed hole such as a rod with a sharp tip is not attached to the outer tube 12 into which the inner tube 11 is inserted.
  • a plurality of bottomed holes 22 are formed in the outer tube 12 by pressing the outer tube 12 so that a part of the outer tube 12 is recessed from the outer surface of the tube 12 toward the center.
  • a part of the outer tube 12 is recessed until the top surface 22a of the bottomed hole 22 of the outer tube 12 contacts the outer periphery of the inner tube 11.
  • a plurality of bottomed holes 22 are arranged in two rows along the extending direction of the outer pipe 12. It forms so that it may become a shape.
  • one row of the outer tubes 12 is defined as one of the radial directions of the outer tube 12 (upward in the drawing), and the other row of the outer tubes 12 is defined as the other of the radial directions of the outer tube 12 (lower in the drawing).
  • Two rows of bottomed holes 22 face each other.
  • the top surface 22a of the bottomed hole 22 disposed in the lower part of the drawing intermittently contacts the outer surface of the inner tube 11. Therefore, at least in the straight pipe portion 7A of the double pipe 7, the inner pipe 11 is sandwiched from both sides in the radial direction of the inner pipe 11 by the top surface 22a of the opposed bottomed hole 22, and thus is fixed to the outer pipe 12. Is done.
  • the intervals between the bottomed holes 22 arranged in a row in the outer tube 12 may be uniform or irregular. Further, the bottomed holes 22 provided on one side in the radial direction of the outer tube 12 and the bottomed holes 22 provided on the other side in the radial direction of the outer tube 12 may be shifted in the extending direction of the pipe. Further, a plurality of bottomed holes 22 may be formed in portions other than the upper and lower sides of the outer surface of the outer tube 12, and these bottomed holes 22 are irregularly scattered in the circumferential direction of the outer tube 12. You may do it.
  • the inner pipe 11 is arranged in the radial direction of the inner pipe 11 by the top surface 22 a of the bottomed hole 22 of the outer pipe 12. Since it is sandwiched from at least both sides, it can be fixed to the outer tube 12. Moreover, since the top surface 22a of the bottomed hole 22 of the outer tube 12 contacts the outer surface of the inner tube 11 at a plurality of locations, the inner tube 11 can be fixed to the outer tube 12 more reliably.
  • the bottomed hole 22 has three or more locations in the circumferential direction of the outer tube 12, and the angle formed by the intersection of the virtual line connecting the center of the outer tube 12 and each bottomed hole 22 is less than 180 °.
  • the inner tube 11 can be sandwiched by the top surfaces 22 a of the three or more bottomed holes 22, and the inner tube 11 can be more stably fixed to the outer tube 12.
  • the inner tube 11 can be positioned substantially at the center of the outer tube 12 (the axial center point of the inner tube 11 can be positioned in the vicinity of the axial center point of the outer tube 12), the outer tube 12 can be positioned.
  • a flow path 35 of a high-pressure refrigerant (first medium) formed between the inner pipe 11 and the inner pipe 11 can be formed around the inner pipe 11, and a high-pressure refrigerant (first medium) and a low-pressure refrigerant (second medium) The efficiency of heat exchange with the medium) can be improved.
  • the double pipe 7 has an aluminum inner pipe 11 and an outer pipe 12. 2) and a bent portion 7B (FIG. 9), the inner tube 11 may have a circular cross section at any point, or the outer periphery may be circular, or FIG. 6 (c) and FIG. b) As in the case of the inner tube 11 in FIG. 8B, the outer tube may have a recess with a spiral recess, the inner tube 11 is connected to the low-pressure side pipe 8B, and the outer tube 12 is connected to the high-pressure side. It is common with the double pipe 7 of Example 1 and Example 2 by the point connected to 8 A of piping parts.
  • the manufacturing method of the double pipe 7 of Example 3 and its modification also has an insertion process and a fixing process.
  • the insertion process is the same as in Example 1 and Example 2, but the fixing process is different from Example 1 and Example 2.
  • the manufacturing method of this double pipe 7, especially the fixing process different from the fixing process of the double pipe 7 of Example 1 or Example 2 is demonstrated below using FIG.6, FIG.7 and FIG.8.
  • the inner tube 11 of the double tube 7 of the third embodiment has a circular outer periphery and has no recess, or FIG. )
  • an inner tube 11 having a recess 31 whose outer periphery is recessed spirally is used.
  • the recess 31 is formed in advance before being inserted into the outer tube 12.
  • the formation of the recess 31 of the inner tube 11 is performed by, for example, mounting a spiral recess forming device that forms a spiral recess on the outer periphery of the inner tube 11 and rotating the periphery of the inner tube 11 in the axial direction of the inner tube 11. Is done.
  • the inner tube 11 has a concave portion 31a and a convex portion 31b on the outer periphery, as shown in FIGS. 6 (c) and 7 (b).
  • the helical dent forming device is a known device shown in FIG. 7 of the cited document 1, for example, the description of the configuration is omitted.
  • the inner tube 11 having an outer diameter smaller than the inner diameter of the outer tube 12 is inserted into the outer tube 12. Even if the inner tube 11 has or does not have the recess 31 whose outer periphery is spirally recessed, the outer diameter of the inner tube 11 is smaller than the inner diameter of the outer tube 12.
  • the above-described helical dent forming device (not shown) is mounted on the outer periphery of the outer tube 12 into which the inner tube 11 is inserted, and the outer tube 12 is rotated while rotating around the outer tube 12.
  • the outer tube 12 is formed with a recess 23 that is spirally recessed.
  • a part of the outer tube 12 is recessed so that the top surface 23 a of the recess 23 that is recessed in the spiral shape of the outer tube 12 continuously contacts the outer surface of the inner tube 11.
  • the top surface 23a of the recess 23 of the outer tube 12 continuously contacts the outer surface of the inner tube 11, and the inner tube 11 is in contact with the outer tube 12.
  • a flow path 35 extending in a spiral shape is formed between the inner tube 11 and the outer tube 12 on the inner surface other than the top surface 23a of the recess 23 of the outer tube 12 and the outer surface of the inner tube 11, and this spiral shape is formed.
  • the high-pressure refrigerant (first medium) flows along the flow path 35.
  • an insertion step of inserting the inner tube 11 into the outer tube 12 is performed.
  • the above-described helical recessing device (not shown) is mounted on the outer periphery of the outer tube 12 in which the inner tube 11 is inserted, and the outer tube 12 is rotated while rotating around the outer tube 12. Is formed in the outer tube 12 to form a recess 23 that is spirally recessed.
  • the top surface 23a of the recess 23 recessed in the spiral shape of the outer tube 12 continuously abuts on the outer surface of the inner tube 11, and the pitch of the recess 23 formed in the outer tube 12 and the inner tube 11 are preliminarily set.
  • the pitch of the provided spiral recesses 31 is adjusted to be substantially the same so that the top surface 23a of the spiral recess 23 of the outer tube 12 continuously contacts the spiral convex portion 31b of the inner tube 11.
  • the outer tube 12 is recessed in a spiral shape.
  • the top surface 23a of the recess 23 of the outer tube 12 continuously contacts the convex portion 31b of the inner tube 11 (the outer surface of the inner tube 11). Because of the contact, the inner tube 11 is fixed to the outer tube 12. Moreover, a spirally extending flow path 35 is formed between the inner tube 11 and the outer tube 12 on the inner surface other than the top surface 23 a of the recess 23 of the outer tube 12 and the outer surface of the recessed portion 31 a of the inner tube 11.
  • the high-pressure refrigerant (first medium) flows along the spiral flow path 35.
  • the pitch of the spiral recesses 23 to be formed is not necessarily the same as the interval of the spiral recesses 31 of the inner tube 11 by making the pitch larger (longer) than the interval of the spiral recesses 31 of the inner tube 11. .
  • the pitch of the spiral recesses 23 formed in the outer tube 12 may be made smaller (shorter) than the interval between the spiral recesses 31 of the inner tube 11.
  • the first medium that flows between the outer tube 12 and the inner tube 11 by reducing (shortening) the pitch is secured for a longer period of time in contact with the outer surface of the inner tube 11, and the first medium that flows through the inner tube 11. Exchange of heat with the second medium is promoted, and the heat exchange performance of the double pipe 7 can be improved.
  • the top surface 23 a of the recess 23 of the outer tube 12 is a part of the plurality of convex portions 31 b of the inner tube 11.
  • the inner tube 11 is fixed to the outer tube 12 by abutting against the convex portion 31b.
  • the spiral recess 23 of the outer tube 12 and the spiral recess 31 of the inner tube 11 serve as a guide for refrigerant flow, and the high-pressure refrigerant (first medium) flows between the inner tube 11 and the outer tube 12. It becomes easy to flow in a spiral.
  • the straight pipe portion 7A of the double pipe 7 is illustrated, and the method of fixing the inner pipe 11 and the outer pipe 12 has been described. Even if the heavy pipe 7 has the bent portion 7B, the inner pipe 11 and the outer pipe 12 can be fixed using the insertion process and the fixing process described so far. A method of fixing the inner tube 11 and the outer tube 12 in the bent portion 7B of the double tube 7 will be described below with an example in which the bottomed hole 22 is formed in the outer tube 12. In addition, as for the inner tube
  • an insertion step of inserting the inner tube 11 having an outer diameter smaller than the inner diameter of the outer tube 12 into the outer tube 12 is performed.
  • a bending process is performed in which the outer tube 12 in which the inner tube 11 is inserted is bent or curved at a predetermined angle.
  • the bottomed hole 22 is formed in the outer tube 12, for example, as shown in FIG. 9B, the inner peripheral side of the outer tube 12 (the portion bent or curved at a predetermined angle).
  • a bottomed hole 22 is formed at a predetermined location on the side relatively closer to the bending center, and the outer peripheral side of the outer tube 12 (a side far from the bending center of a portion bent or curved at a predetermined angle) And a fixing step of forming the bottomed holes 22 at two predetermined positions on both sides in the extending direction of the outer tube 12 with respect to the bottomed holes 22 on the inner peripheral side of the outer tube 12 is performed. Even in this fixing step, the bottomed hole 22 is formed by denting a part of the outer tube 12 until the top surface 22a of the bottomed hole 22 of the outer tube 12 contacts the outer periphery of the inner tube 11.
  • the inner tube 11 is supported by the top surfaces 22a of the plurality of bottomed holes 22 from the outer peripheral side and the inner peripheral side of the outer tube 12, so that the inner tube 11 is It is fixed to the outer tube 12. Therefore, even after the outer tube 12 into which the inner tube 11 is inserted is bent or bent by a bending process, the outer tube 12 and the inner tube 11 can be easily fixed by the fixing process.
  • a part of the outer tube 12 is recessed so that the top surface 22 a of the bottomed hole 22 of the outer tube 12 reaches the inner side of the outer periphery of the inner tube 11.
  • a recess 32 is formed also in the inner tube 11 and the top surface 22a of the bottomed hole 22 and the recess 32 of the inner tube 11 are fitted.
  • a part of the outer tube 12 is recessed in the extending direction of the outer tube 12 such that the top surface 21 a of the recess 21 reaches the inner side of the outer periphery of the inner tube 11, or the top surface of the recess 23.
  • the outer tube 12 may be helically recessed so that 23a reaches the inner side of the outer periphery of the inner tube 11.
  • the recess 32 is formed in the inner tube 11, and the outer tube 12 and the inner tube 11 are fitted by the recess 32 and the top surface 21 a of the recess 21 or the recess 32 and the top surface 23 a of the recess 23. Therefore, the outer tube 12 and the inner tube 11 can be easily and firmly fixed.
  • a spiral recess 23 is formed by using a spiral recess forming device, while a plurality of bottomed holes 22 and 22 are formed in a bent portion 7B that is bent or curved at a predetermined angle. To do. In this way, an appropriate fixing method can be selected according to the shape of the double pipe 7.
  • the fixing step after first performing the step of firmly fixing the outer tube 12 and the inner tube 11 as shown in FIG. May be implemented. Since the position of the inner tube 11 can be firmly fixed to the outer tube 12 at an early stage, unintentional displacement between the outer tube 12 and the inner tube 11 in the subsequent fixing process can be prevented.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Heat-Exchange Devices With Radiators And Conduit Assemblies (AREA)
  • Air-Conditioning For Vehicles (AREA)

Abstract

To provide a method for manufacturing a double pipe where it is possible to easily insert an inner pipe into an outer pipe, and to easily and reliably secure the outer pipe and the inner pipe irrespective of the extension-direction dimensions of straight parts or curved parts. The steps for manufacturing a double pipe (7) used as an internal heat exchanger in a refrigeration cycle mounted in a vehicle comprise an insertion step for inserting an inner pipe (11) having a smaller outer diameter than the inner diameter of an outer pipe (12) into the outer pipe (12), and a securing step for securing the outer pipe (12) and the inner pipe (11) by indenting a portion of the outer pipe (12) until contact is made with the outer circumference of the inner pipe (11), said securing step being performed after the insertion step. In the securing step, e.g., the outer pipe (12) is indented so as to have a plurality of bottomed holes (22) present therein in various locations.

Description

二重管の製造方法Manufacturing method of double pipe
　この発明は、車両に搭載される冷凍サイクルの内部熱交換器として用いられる二重管を容易に製造するための方法に関する。 The present invention relates to a method for easily manufacturing a double pipe used as an internal heat exchanger of a refrigeration cycle mounted on a vehicle.
　冷凍サイクルの冷凍効率を向上させるために、高圧側の媒体と低圧側の媒体とを熱交換させる内部熱交換器として、例えば特許文献１や特許文献２等に開示される二重管を用いることが公知となっている。 In order to improve the refrigeration efficiency of the refrigeration cycle, for example, a double pipe disclosed in Patent Document 1, Patent Document 2, etc. is used as an internal heat exchanger for exchanging heat between the medium on the high pressure side and the medium on the low pressure side. Is known.
　これらの特許文献１及び特許文献２に開示される二重管は、外管とこの外管に挿入された内管とを備え、外管と内管との間を通流する第一の媒体と、内管を通流する第二の媒体との間で熱交換を行う構成となっている。 These double pipes disclosed in Patent Document 1 and Patent Document 2 include a first medium that includes an outer pipe and an inner pipe inserted into the outer pipe, and flows between the outer pipe and the inner pipe. And a heat exchange between the second medium flowing through the inner pipe.
　このように、二重管は、外管と内管との間に第一の媒体が通流する隙間を有するので、車両の振動が二重管に伝達されたときに、外管と内管とがそれぞれ振動して外管と内管とが接触し、異音の発生や、外管や内管が損傷するおそれがある。 Thus, since the double pipe has a gap through which the first medium flows between the outer pipe and the inner pipe, when the vibration of the vehicle is transmitted to the double pipe, the outer pipe and the inner pipe May vibrate and the outer tube and the inner tube come into contact with each other, generating abnormal noise and damaging the outer tube and the inner tube.
　そこで、特許文献１では、二重管を、直管部とこの直管部の両側に配された曲げ部とを有するよう構成した。直管部では内管の外面（外周）と外管の内面（内周）とが接触しないか、内管の外面が外管の内面の一方にだけ接触する一方、曲げ部では内管の外面と外管の内面とが径方向の複数方向で接触する。このような二重管の構成とすることにより、外管と内管とが固定され、二重管に振動が伝達されたとしても、異音の発生や、内管や外管の破損を防止することができる、としている。 Therefore, in Patent Document 1, the double pipe is configured to have a straight pipe part and bent parts arranged on both sides of the straight pipe part. In the straight pipe part, the outer surface (outer circumference) of the inner pipe does not contact the inner surface (inner circumference) of the outer pipe, or the outer surface of the inner pipe contacts only one of the inner surfaces of the outer pipe, while in the bent part, the outer surface of the inner pipe And the inner surface of the outer tube are in contact in a plurality of radial directions. By adopting such a double pipe configuration, the outer pipe and the inner pipe are fixed, and even if vibration is transmitted to the double pipe, generation of abnormal noise and damage to the inner pipe and outer pipe are prevented. It can be done.
　また、特許文献２に開示される二重管は、内管の直管部に螺旋状の凹凸部が設けられ、この凸凹部のうちの凸部分が、直管部とされた外管の内面に当接した構成となっている。 In addition, the double pipe disclosed in Patent Document 2 is provided with a spiral concavo-convex part in the straight pipe part of the inner pipe, and the convex part of the convex concave part is the inner surface of the outer pipe. It is the structure which contact | abutted.
特開２００６－１６２２４１号公報JP 2006-162241 A 特開２０１３－１１３５２５号公報JP 2013-113525 A
　しかしながら、特許文献１に開示される二重管の構成や製造方法では、二重管に振動が伝達されたときに、内管や外管の接触による異音の発生や、内管や外管の破損の防止を確実に行うことが難しい。 However, in the structure and manufacturing method of the double pipe disclosed in Patent Document 1, when vibration is transmitted to the double pipe, generation of abnormal noise due to contact of the inner pipe and the outer pipe, and the inner pipe and the outer pipe It is difficult to reliably prevent damage to the
　特許文献１の二重管の製造方法について概説すると、螺旋状の溝部が形成された内管を外管に挿入する挿入工程を行い、次に、内管と外管とを同時に曲げる曲げ工程を行って曲げ部を形成し、形成した曲げ部の箇所のみで内管を外管と複数箇所で接触させるようにしている。 An outline of the manufacturing method of the double pipe of Patent Document 1 will be described. An insertion process for inserting an inner pipe formed with a spiral groove into an outer pipe is performed, and then a bending process for bending the inner pipe and the outer pipe at the same time is performed. The bent portion is formed by performing the operation, and the inner tube is brought into contact with the outer tube at a plurality of positions only at the formed bent portion.
　このように曲げ部を構成することで、曲げ部では外管と内管とが固定されるものの、直管部のうち曲げ部の近傍では、外管と内管とが固定されていないだけでなく、外管の内面と内管の外面とが近接し、二重管に振動が伝達されると接触するおそれがある。また、一方の曲げ部と他方の曲げ部との間が長い（直管部の寸法が配管の延長方向に長い）場合には、二重管に振動が伝達されると、外管や内管がそれぞれ撓んで、外管の内面と内管の外面とが接触するおそれがある。そもそも、特許文献１のように必ず２か所の曲げ部を設けるとすると、二重管の設計自由度が著しく制限される。 By configuring the bending portion in this way, the outer tube and the inner tube are fixed in the bending portion, but the outer tube and the inner tube are not fixed in the vicinity of the bending portion in the straight tube portion. In other words, the inner surface of the outer tube and the outer surface of the inner tube are close to each other, and there is a risk of contact when vibration is transmitted to the double tube. Also, if the distance between one bent part and the other bent part is long (the dimension of the straight pipe part is long in the extending direction of the pipe), when vibration is transmitted to the double pipe, the outer pipe and the inner pipe May be bent, and the inner surface of the outer tube may come into contact with the outer surface of the inner tube. In the first place, if two bent portions are always provided as in Patent Document 1, the degree of freedom in design of the double pipe is significantly limited.
　この点、特許文献２に開示される二重管は、螺旋状の凸凹部が形成された内管の凸部が、直管とされた外管の内面に接触するように外管に挿入されているので、車両からの振動が伝達されたときに、直管部における異音の発生や、内管や外管の破損の防止が図られることが予見される。しかしながら、曲げ部においては外管と内管とが固定されておらず、外管や内管がそれぞれ撓んで、外管の内面と内管の外面とが接触するおそれがある。特に、曲げ部の曲げＲが大きく設定されるほど、接触するおそれが高くなる。また、内管と外管とが固定される直管部について、そもそも、特許文献２では、螺旋状の凸凹部が予め形成された内管をどのように外管の内面に固定するのか、二重管の製造方法の固定工程が開示されていない。 In this regard, the double pipe disclosed in Patent Document 2 is inserted into the outer pipe so that the convex part of the inner pipe in which the spiral convex concave part is formed is in contact with the inner surface of the outer pipe that is a straight pipe. Therefore, it is foreseen that when the vibration from the vehicle is transmitted, the generation of noise in the straight pipe portion and the damage of the inner pipe and the outer pipe are prevented. However, the outer tube and the inner tube are not fixed at the bent portion, and the outer tube and the inner tube may be bent, and the inner surface of the outer tube and the outer surface of the inner tube may come into contact with each other. In particular, the larger the bend R of the bent portion, the higher the risk of contact. In addition, regarding the straight pipe portion to which the inner pipe and the outer pipe are fixed, in Patent Document 2, how to fix the inner pipe in which the spiral convex and concave portions are formed in advance to the inner surface of the outer pipe is two. The fixing process of the manufacturing method of a heavy pipe is not disclosed.
　そこで、本発明は、曲げ部の有無にかかわらず外管と内管とを固定でき、高い耐振性を備えた二重管を容易に製造できる二重管の製造方法を提供することを目的としている。 Accordingly, an object of the present invention is to provide a method of manufacturing a double tube that can fix an outer tube and an inner tube regardless of the presence or absence of a bending portion and can easily manufacture a double tube having high vibration resistance. Yes.
　この発明に係る二重管の製造方法は、車両に搭載される冷凍サイクルの内部熱交換器として用いられる二重管の製造方法であって、外管に、前記外管の内径よりも外径が小さい内管を挿入する挿入工程と、前記挿入工程の後に行う工程であって、前記外管の一部を前記内管の外周に当接するまで凹ませて前記外管と前記内管とを固定する固定工程とを有することを特徴としている（請求項１）。なお、下記のように、内管と外管との間を通流する媒体を第一の媒体、内管内を通流する媒体を第二の媒体としている。これらの媒体は、例えば冷媒等である。 A manufacturing method of a double pipe according to the present invention is a manufacturing method of a double pipe used as an internal heat exchanger of a refrigeration cycle mounted on a vehicle, and the outer pipe has an outer diameter that is larger than the inner diameter of the outer pipe. An insertion step of inserting a small inner tube, and a step performed after the insertion step, in which a part of the outer tube is recessed until it comes into contact with the outer periphery of the inner tube, and the outer tube and the inner tube are And a fixing step for fixing. (Claim 1) As will be described below, the medium that flows between the inner tube and the outer tube is the first medium, and the medium that flows in the inner tube is the second medium. These media are, for example, refrigerants.
　これにより、外管に、この外管の内径よりも外径が小さい内管を挿入させる工程と、内管が挿入された状態の外管の一部を凹ませて、外管の凹みと内管とを当接させる工程とにより、外管と内管との固定を行うので、曲げ部の有無にかかわらず外管と内管とを容易に固定することができる。 As a result, a step of inserting an inner tube having an outer diameter smaller than the inner diameter of the outer tube into the outer tube, and a part of the outer tube with the inner tube inserted therein are recessed, and Since the outer tube and the inner tube are fixed by the step of contacting the tube, the outer tube and the inner tube can be easily fixed regardless of the presence or absence of the bent portion.
　請求項２に記載の発明に係る二重管の製造方法では、前記固定工程は、前記外管を、前記外管の延長方向に沿って凹ませる工程であることを特徴としている。 In the method for manufacturing a double pipe according to the invention described in claim 2, the fixing step is a step of denting the outer pipe along the extending direction of the outer pipe.
　これにより、一定の方向から外管を凹ませるため、外管または治具を回転させる工程が不要となるので、二重管を容易に製造することができる。 Thereby, since the outer tube is recessed from a certain direction, the step of rotating the outer tube or the jig becomes unnecessary, and thus the double tube can be easily manufactured.
　請求項３に記載の発明に係る二重管の製造方法では、前記固定工程は、前記外管を、複数の有底孔が点在するように凹ませる工程であることを特徴としている。 In the double pipe manufacturing method according to the invention of claim 3, the fixing step is a step of denting the outer pipe so that a plurality of bottomed holes are scattered.
　これにより、外管を、任意の位置で凹ませることが可能であるので、二重管の生産性を向上させることができると共に、凹みの設計自由度を向上させることができる。 This allows the outer tube to be recessed at an arbitrary position, so that the productivity of the double tube can be improved and the design freedom of the recess can be improved.
　請求項４に記載の発明に係る二重管の製造方法では、前記固定工程は、前記外管を、螺旋状に凹ませる工程であることを特徴としている。螺旋状の凹みの数は、１つであっても、２以上であっても良い。 In the method for manufacturing a double tube according to the invention described in claim 4, the fixing step is a step of recessing the outer tube in a spiral shape. The number of spiral dents may be one or two or more.
　これにより、外管に形成された螺旋状の凹みをガイドとして、外管と内管との間を通流する第一の媒体を螺旋状に通流させて、内管を通流する第二の媒体との熱の交換率を向上させた二重管を、容易な製造方法で提供することができる。 As a result, the first medium flowing between the outer tube and the inner tube is caused to flow spirally using the spiral recess formed in the outer tube as a guide, and the second medium flows through the inner tube. A double tube with improved heat exchange rate with the medium can be provided by an easy manufacturing method.
　請求項５に記載の発明に係る二重管の製造方法では、前記固定工程は、前記外管を螺旋状に凹ませるときに、前記外管の螺旋状に凹ませた部位の頂面を、連続して前記内管に当接させる工程であることを特徴としている。 In the method of manufacturing a double pipe according to the invention described in claim 5, when the fixing step causes the outer pipe to be helically recessed, the top surface of the portion of the outer pipe that is helically recessed is It is a process of continuously contacting the inner pipe.
　これにより、外管の螺旋状に凹ませた部位の頂面が連続して内管に当接するので、外管と内管との間を通流する第一の媒体は、二重管の延長方向に短絡することが防止され、確実に螺旋状に通流することから、内管を通流する第二の媒体との熱の交換率を容易に向上させることができる。 As a result, the top surface of the spirally recessed portion of the outer tube continuously contacts the inner tube, so that the first medium flowing between the outer tube and the inner tube is an extension of the double tube. Since a short circuit in the direction is prevented and the spiral flow is ensured, the heat exchange rate with the second medium flowing through the inner tube can be easily improved.
　請求項６に記載の発明に係る二重管の製造方法では、前記内管は、外周が螺旋状に凹んだ凹みを有することを特徴としている。 In the method for manufacturing a double pipe according to the invention described in claim 6, the inner pipe has a recess whose outer periphery is recessed spirally.
　これにより、内管の外周が螺旋状の凹んだ凹みをガイドとして、外管と内管との間を通流する第一の媒体を螺旋状に通流させて、内管を通流する第二の媒体との熱の交換率を向上させた二重管を、容易な製造方法で提供することができる。 As a result, the first medium flowing between the outer tube and the inner tube is spirally passed through the inner tube through the inner tube, with the outer periphery of the inner tube serving as a guide. A double tube with an improved heat exchange rate with the second medium can be provided by an easy manufacturing method.
　請求項７に記載の発明に係る二重管の製造方法では、前記挿入工程と前記固定工程との間に行われる工程として、前記内管が挿入された前記外管を所定の角度に曲げる又は湾曲させる曲げ加工を有し、前記固定工程を、前記外管のうち前記曲げ加工により曲げられ又は湾曲させた部位に行うことを特徴としている。 In the method of manufacturing a double pipe according to the invention of claim 7, as the process performed between the insertion process and the fixing process, the outer pipe in which the inner pipe is inserted is bent to a predetermined angle, or A bending process for bending is provided, and the fixing step is performed on a portion of the outer tube that is bent or bent by the bending process.
　これにより、内管が挿入された外管が曲げ加工により曲げられ又は湾曲させられた後であっても、曲げられ又は湾曲された部位において、外管と内管とを容易に固定することができる。 Thereby, even after the outer tube into which the inner tube is inserted is bent or bent by bending, the outer tube and the inner tube can be easily fixed at the bent or bent portion. it can.
　請求項８に記載の発明に係る二重管の製造方法では、前記固定工程は、前記外管の一部が前記内管の外周よりも内側に達するまで、前記外管の一部を凹ませる工程であることを特徴としている。 In the method of manufacturing a double pipe according to the invention described in claim 8, the fixing step causes the part of the outer pipe to be recessed until a part of the outer pipe reaches the inner side of the outer periphery of the inner pipe. It is a process.
　これにより、固定工程として外管の一部を凹ませるときに、外管の一部が内管の外周よりも内側に達するまで凹ませることで、外管と内管とが嵌合するので、外管と内管とを容易に、しかも強固に固定することができる。 Thereby, when a part of the outer tube is recessed as a fixing step, the outer tube and the inner tube are fitted by being recessed until a part of the outer tube reaches the inner side of the outer periphery of the inner tube. The outer tube and the inner tube can be easily and firmly fixed.
　請求項９に記載の発明に係る二重管の製造方法では、前記外管と前記内管とは、アルミニウム製であることを特徴としている。これにより、管の塑性変形を比較的容易に行うことができるので、二重管の製造に適している。 In the method for manufacturing a double pipe according to the invention described in claim 9, the outer pipe and the inner pipe are made of aluminum. Thereby, since plastic deformation of a pipe can be performed comparatively easily, it is suitable for manufacture of a double pipe.
　以上に述べたように、本発明によれば、外管に、この外管の内径よりも外径が小さい内管を挿入させる工程と、内管が挿入された状態の外管の一部を凹ませて、外管の凹みと内管とを当接させる工程とにより、外管と内管との固定を行うので、曲げ部の有無にかかわらず外管と内管とを容易に固定することができる。 As described above, according to the present invention, the step of inserting an inner tube having an outer diameter smaller than the inner diameter of the outer tube into the outer tube, and a part of the outer tube with the inner tube inserted therein The outer tube and the inner tube are fixed by the step of making the dent and the inner tube are brought into contact with the inner tube, so that the outer tube and the inner tube can be easily fixed regardless of the presence or absence of the bent portion. be able to.
図１は、二重管を内部熱交換器として備えた冷凍サイクルの概略図である。FIG. 1 is a schematic view of a refrigeration cycle provided with a double pipe as an internal heat exchanger. 図２は、実施例１における二重管の概略を示した説明図であり、図２（ａ）は、二重管の斜視図、図２（ｂ）は、二重管の断面図である。2A and 2B are explanatory views showing an outline of the double tube in Example 1. FIG. 2A is a perspective view of the double tube, and FIG. 2B is a cross-sectional view of the double tube. . 図３（ａ）は、図２（ｂ）のＡ－Ａ線断面図の拡大図、図３（ｂ）は、図２（ｂ）のＢ－Ｂ線断面図の拡大図である。3A is an enlarged view of the cross-sectional view taken along the line AA in FIG. 2B, and FIG. 3B is an enlarged view of the cross-sectional view taken along the line BB of FIG. 2B. 図４は、実施例２における二重管の概略を示した説明図であり、図４（ａ）は、二重管の斜視図、図４（ｂ）は、二重管の断面図である。4A and 4B are explanatory views showing an outline of a double tube in Example 2. FIG. 4A is a perspective view of the double tube, and FIG. 4B is a cross-sectional view of the double tube. . 図５（ａ）は、図４（ｂ）のＣ－Ｃ線断面図の拡大図、図５（ｂ）は、図４（ｂ）のＤ－Ｄ線断面図の拡大図である。5A is an enlarged view of the cross-sectional view taken along the line CC of FIG. 4B, and FIG. 5B is an enlarged view of the cross-sectional view taken along the line DD of FIG. 4B. 図６は、実施例３における二重管の概略を示した説明図であり、図６（ａ）は、二重管の斜視図、図６（ｂ）は、二重管の断面図であり、内管として凹みがないものを用いた態様を示し、図６（ｃ）は、二重管の断面図であり、内管として外周が螺旋状に凹んだ凹みがあるものを用いた態様を示している。6A and 6B are explanatory views showing an outline of a double tube in Example 3. FIG. 6A is a perspective view of the double tube, and FIG. 6B is a cross-sectional view of the double tube. Fig. 6 (c) is a cross-sectional view of a double pipe, and shows an embodiment using an inner tube having a dent whose outer periphery is spirally recessed. Show. 図７（ａ）は、図６（ｂ）のＥ－Ｅ線断面図の拡大図であり、図７（ｂ）は、図６（ｃ）のＦ－Ｆ線断面図の拡大図である。7A is an enlarged view of the cross-sectional view taken along the line EE of FIG. 6B, and FIG. 7B is an enlarged view of the cross-sectional view taken along the line FF of FIG. 6C. 図８は、実施例３の変形例にかかる二重管の概略を示した説明図であり、図８（ａ）は、二重管の斜視図、図８（ｂ）は、二重管の断面図である。8A and 8B are explanatory views showing an outline of a double pipe according to a modification of the third embodiment. FIG. 8A is a perspective view of the double pipe, and FIG. It is sectional drawing. 図９は、実施例２の凹みを基にして、曲げ加工の後に固定工程を行う態様を示した断面図であり、図９（ａ）は固定工程前を示し、図９（ｂ）は固定工程後を示している。FIG. 9 is a cross-sectional view showing a mode in which a fixing process is performed after bending based on the dent of Example 2, FIG. 9 (a) shows a state before the fixing process, and FIG. 9 (b) shows a fixing process. It shows after the process. 図１０は、実施例２の変形例として、固定工程において、外管の内面の一部を内管の外周よりも内側に凹ませる工程の後の二重管を示した断面図である。FIG. 10 is a cross-sectional view showing a double tube after a step of denting a part of the inner surface of the outer tube to the inside of the outer periphery of the inner tube in the fixing step as a modification of the second embodiment.
　以下、この発明の実施形態について添付図面を参照しながら説明する。 Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
　図１において、下記する二重管７を有する冷凍サイクル１の一例が示されている。この冷凍サイクル１は、車両に搭載されて、図示しない車両用空調装置の一部を構成するものである。 FIG. 1 shows an example of a refrigeration cycle 1 having a double pipe 7 described below. The refrigeration cycle 1 is mounted on a vehicle and constitutes a part of a vehicle air conditioner (not shown).
　そして、冷凍サイクル１は、冷媒を圧縮する圧縮機２と、この圧縮機２で圧縮された冷媒を冷却する放熱器３と、この放熱器３により冷却された冷媒を減圧して膨張する膨張装置４と、この膨張装置４により減圧された冷媒を蒸発する蒸発器５と、この蒸発器５から流出した冷媒を気層と液層とに分離して気層の冷媒を圧縮機２に送るアキュムレータ６と、このアキュムレータ６から圧縮機２へ導かれる低圧冷媒と放熱器３から膨張装置４へ導かれる高圧冷媒とを熱交換する内部熱交換器として用いられる二重管７とを有している。 The refrigeration cycle 1 includes a compressor 2 that compresses the refrigerant, a radiator 3 that cools the refrigerant compressed by the compressor 2, and an expansion device that expands the refrigerant cooled by the radiator 3 by decompressing the refrigerant. 4, an evaporator 5 that evaporates the refrigerant decompressed by the expansion device 4, and an accumulator that separates the refrigerant flowing out of the evaporator 5 into a gas layer and a liquid layer and sends the refrigerant in the gas layer to the compressor 2 6 and a double pipe 7 used as an internal heat exchanger for exchanging heat between the low-pressure refrigerant led from the accumulator 6 to the compressor 2 and the high-pressure refrigerant led from the radiator 3 to the expansion device 4. .
　圧縮機２と放熱器３、放熱器３と二重管７の高圧冷媒が通流する管、二重管７の高圧冷媒が通流する管と膨張装置４、膨張装置４と蒸発器５、蒸発器５とアキュムレータ６、アキュムレータ６と二重管７の低圧冷媒が通流する管、及び、二重管７の低圧冷媒が通流する管と圧縮機２とは、配管８を介して適宜接続されている。なお、配管８のうち圧縮機２の吐出口から膨張装置４の流入口までの部位が高圧側配管部８Ａをなし、配管８のうち膨張装置４の流出口から圧縮機２の吸入口までの部位が低圧側配管部８Ｂをなしている。 The compressor 2 and the radiator 3, the pipe through which the high-pressure refrigerant of the radiator 3 and the double pipe 7 flows, the pipe through which the high-pressure refrigerant of the double pipe 7 flows and the expansion device 4, the expansion device 4 and the evaporator 5, The evaporator 5 and the accumulator 6, the pipe through which the low-pressure refrigerant flows through the accumulator 6 and the double pipe 7, and the pipe through which the low-pressure refrigerant flows through the double pipe 7 and the compressor 2 are appropriately connected via the pipe 8. It is connected. Note that a portion of the pipe 8 from the discharge port of the compressor 2 to the inlet of the expansion device 4 forms a high-pressure side piping portion 8A, and of the pipe 8, the outlet from the expansion device 4 to the suction port of the compressor 2. The site | part has comprised the low voltage | pressure side piping part 8B.
　ところで、二重管７について、図２及び図３においてこの発明の実施例１が示され、図４及び図５においてこの発明の実施例２が示され、図６から図８においてこの発明の実施例３及びその変形例が示されている。以下、実施例１、実施例２、実施例３及びその変形例について各々説明する。 2 and 3 show the first embodiment of the present invention, FIGS. 4 and 5 show the second embodiment of the present invention, and FIGS. 6 to 8 show the embodiment of the present invention. Example 3 and its variations are shown. Hereinafter, the first embodiment, the second embodiment, the third embodiment, and modifications thereof will be described.
　実施例１の二重管７は、図２及び図３に示されるように、いずれもアルミニウム製の内管１１と外管１２とを有し、外管１２に内管１１が挿入されている。二重管７は、直管部７Ａ（図２）と曲げ部７Ｂ（図９）とを有したものとしても良い。そして、実施例１の内管１１は、図２及び図３に示されるように、外周に凹みが形成されておらず、いずれの箇所の断面も外周が円状をしている。もっとも、内管１１の外径が外管１２の内径よりも小さければ、下記する図６（ｃ）、図７（ｂ）、図８（ｂ）の内管１１と同様に、内管１１は、外周が螺旋状に凹んだ凹みを有するものとしても良い。 As shown in FIGS. 2 and 3, the double pipe 7 of the first embodiment has an aluminum inner pipe 11 and an outer pipe 12, and the inner pipe 11 is inserted into the outer pipe 12. . The double pipe 7 may have a straight pipe portion 7A (FIG. 2) and a bent portion 7B (FIG. 9). And as FIG.2 and FIG.3 shows, the inner tube | pipe 11 of Example 1 is not formed in the outer periphery, but the outer periphery is circular in the cross section of any location. However, if the outer diameter of the inner tube 11 is smaller than the inner diameter of the outer tube 12, the inner tube 11 is similar to the inner tube 11 shown in FIGS. 6 (c), 7 (b) and 8 (b) described below. The outer periphery may have a dent that is spirally recessed.
　そして、実施例１では、内管１１は、延長方向の両側が低圧側配管部８Ｂと接続され、外管１２は、延長方向の両側端近傍の外面に形成された孔１２ａを介して高圧側配管部８Ａと接続されている。ここで、内管１１が低圧側配管部８Ｂと接続し、外管１２が高圧側配管部８Ａと接続する構成であれば、その接続の方法は特に問わない。また、実施例１では、外管１２の延長方向の両側が内管１１により閉塞されているが、外管１２の延長方向の両側端から冷媒が漏れない構成になっていれば、外管１２の延長方向の両側を閉塞する方法も特に問わない。 In the first embodiment, the inner pipe 11 is connected to the low-pressure side pipe portion 8B on both sides in the extending direction, and the outer pipe 12 is connected to the high-pressure side via holes 12a formed on the outer surfaces near both ends in the extending direction. It is connected to the piping part 8A. Here, the connection method is not particularly limited as long as the inner pipe 11 is connected to the low-pressure side piping part 8B and the outer pipe 12 is connected to the high-pressure side piping part 8A. In the first embodiment, both sides of the outer tube 12 in the extending direction are closed by the inner tube 11, but if the refrigerant does not leak from both ends in the extending direction of the outer tube 12, the outer tube 12. The method of closing both sides in the extending direction is not particularly limited.
　これにより、二重管７の内管１１内を低圧冷媒（第二の媒体）が通流し、外管１２と内管１１との間を高圧冷媒（第一の媒体）が通流するので、低圧冷媒と高圧冷媒との間で熱の交換を行うことができる。 Thereby, the low-pressure refrigerant (second medium) flows through the inner pipe 11 of the double pipe 7, and the high-pressure refrigerant (first medium) flows between the outer pipe 12 and the inner pipe 11, Heat can be exchanged between the low-pressure refrigerant and the high-pressure refrigerant.
　二重管７の内管１１と外管１２とは、下記の製造方法によって固定されている。この二重管７の製造方法、特に外管１２に凹み２１を形成して内管１１と外管１２とを固定する固定工程について、図２及び図３を用いて以下に説明する。 The inner tube 11 and the outer tube 12 of the double tube 7 are fixed by the following manufacturing method. A method of manufacturing the double pipe 7, in particular, a fixing process for fixing the inner pipe 11 and the outer pipe 12 by forming the recess 21 in the outer pipe 12 will be described below with reference to FIGS. 2 and 3.
　まず、挿入工程では、外管１２にこの外管１２の内径よりも小さな外径の内管１１を挿入する。 First, in the insertion step, the inner tube 11 having an outer diameter smaller than the inner diameter of the outer tube 12 is inserted into the outer tube 12.
　次に、固定工程では、図２（ａ）に示される、軸部５１に回転板５２が回転自在に支持された凹み形成機具５０を、内管１１の挿入された外管１２に対し、上方から外面に当てた後、さらに外管１２の一部を内管１１へと押しこむ。そして、外管１２の延長方向に沿って回転板５２を回転させつつ押し動かす。この固定工程では、外管１２の凹み２１の頂面２１ａが内管１１の外周に当接しても更に内管１１を押し、外管１２の凹み２１とは反対側の内面に内管１１の外面が当接するまで、凹み形成機具５０の回転板５２で外管１２の一部を凹ませるようにする。 Next, in the fixing step, as shown in FIG. 2A, the dent forming tool 50 in which the rotating plate 52 is rotatably supported by the shaft portion 51 is moved upward with respect to the outer tube 12 in which the inner tube 11 is inserted. Then, a part of the outer tube 12 is further pushed into the inner tube 11. Then, the rotary plate 52 is pushed and moved along the extending direction of the outer tube 12. In this fixing step, even if the top surface 21a of the recess 21 of the outer tube 12 comes into contact with the outer periphery of the inner tube 11, the inner tube 11 is further pushed, and the inner tube 11 is pressed against the inner surface of the outer tube 12 opposite to the recess 21. Until the outer surface comes into contact, a part of the outer tube 12 is recessed with the rotating plate 52 of the recess forming device 50.
　これにより、図２及び図３に示されるように、外管１２の上方に当該外管１２の延長方向に沿って直線状に延びる凹み２１が形成され、凹み２１の頂面２１ａと、外管１２の内面のうち凹み２１の反対側（外管１２の内面の下方）とが、内管１１の外面に、配管の延長方向に沿って連続して当接する。従って、少なくとも二重管７の直管部７Ａにおいては、内管１１は、外管１２の凹み２１の頂面２１ａと、外管１２の凹み２１に対し反対側の内面とで上下方向から挟まれるので、外管１２に固定される。 As a result, as shown in FIGS. 2 and 3, a recess 21 extending linearly along the extending direction of the outer tube 12 is formed above the outer tube 12, and the top surface 21a of the recess 21 and the outer tube Of the inner surface of 12, the opposite side of the recess 21 (below the inner surface of the outer tube 12) is in continuous contact with the outer surface of the inner tube 11 along the extending direction of the pipe. Therefore, at least in the straight pipe portion 7A of the double pipe 7, the inner pipe 11 is sandwiched from above and below between the top surface 21a of the recess 21 of the outer pipe 12 and the inner surface opposite to the recess 21 of the outer pipe 12. Therefore, it is fixed to the outer tube 12.
　このように、外管１２への内管１１の挿入は外管１２の内径よりも小さな内径の内管１１を挿入するので円滑に挿入工程を行うことができ、外管１２に一定の方向から凹み２１を形成する固定工程により内管１１と外管１２とを固定することができるので、二重管７の製造を容易に行うことができる。また、曲げ部の有無にかかわらず、二重管７の直管部７Ａにて内管１１と外管１２とを固定できる。 As described above, the insertion of the inner tube 11 into the outer tube 12 inserts the inner tube 11 having an inner diameter smaller than the inner diameter of the outer tube 12, so that the insertion process can be smoothly performed. Since the inner tube 11 and the outer tube 12 can be fixed by the fixing step for forming the recess 21, the double tube 7 can be easily manufactured. In addition, the inner tube 11 and the outer tube 12 can be fixed by the straight tube portion 7A of the double tube 7 regardless of the presence or absence of the bent portion.
　尚、固定工程において、外管１２に凹み２１を形成するにあたり、一定の方向から外管１２の一部を凹ませて凹み２１を形成すれば良いので、必ずしも外管１２に対し上方から凹ませて凹み２１を形成する工程に限定されない。図示しないが、斜め上方や、側方や、下方から、凹み形成機具５０等の機具を用いて凹ませて、凹み２１を形成するようにしても良い。さらに、外管１２に対し複数の方向から凹み２１を形成するようにしてもよい。この場合には、内管１１は、複数の凹み２１の頂面２１ａ、２１ａと当接して、外管１２に固定される。 In the fixing step, when forming the recess 21 in the outer tube 12, it is only necessary to form a recess 21 by recessing a part of the outer tube 12 from a certain direction. Thus, the present invention is not limited to the step of forming the recess 21. Although not shown, the recess 21 may be formed by indenting from a diagonally upper side, from the side, or from the lower side using a device such as the recess forming device 50. Furthermore, you may make it form the dent 21 with respect to the outer tube | pipe 12 from several directions. In this case, the inner tube 11 is fixed to the outer tube 12 in contact with the top surfaces 21 a and 21 a of the plurality of recesses 21.
　実施例２の二重管７は、図４及び図５に示されるように、いずれもアルミニウム製の内管１１と外管１２とを有する点、直管部７Ａ（図２）と曲げ部７Ｂ（図９）とを有したものとしても良い点、内管１１はいずれの箇所の断面も外周が円状をしても、あるいは下記する図６（ｃ）、図７（ｂ）、図８（ｂ）の内管１１と同様に外周が螺旋状に凹んだ凹みを有しても良い点、内管１１が低圧側配管部８Ｂと接続され、外管１２が高圧側配管部８Ａと接続された構成である点で、実施例１の二重管７と共通している。従って、実施例２の二重管７のうち実施例１の二重管７と同様の構成や機能については、実施例１の二重管７と同じ符号を付すことでその説明を省略する。 As shown in FIGS. 4 and 5, the double pipe 7 of the second embodiment has an inner pipe 11 and an outer pipe 12 made of aluminum, a straight pipe portion 7 </ b> A (FIG. 2), and a bent portion 7 </ b> B. The inner tube 11 may have a circular shape on the outer periphery of the inner tube 11 or the outer periphery of the inner tube 11 or may be the following FIG. 6 (c), FIG. 7 (b), FIG. The outer tube 12 may be connected to the low-pressure side piping portion 8B, and the outer tube 12 may be connected to the high-pressure side piping portion 8A. It is common with the double pipe 7 of Example 1 by the point which was made the structure. Therefore, about the structure and function similar to the double tube 7 of Example 1 among the double tubes 7 of Example 2, the description is abbreviate | omitted by attaching | subjecting the same code | symbol as the double tube 7 of Example 1. FIG.
　実施例２の二重管７の製造方法も、挿入工程と固定工程とがある。挿入工程については実施例１と同じであるが、固定工程については実施例１と異なっている。この二重管７の製造方法、特に実施例１の二重管７の固定工程と異なる固定工程について、図４及び図５を用いて以下に説明する。 The manufacturing method of the double pipe 7 of Example 2 also includes an insertion process and a fixing process. The insertion process is the same as that of the first embodiment, but the fixing process is different from that of the first embodiment. The manufacturing method of this double pipe 7, especially the fixing process different from the fixing process of the double pipe 7 of Example 1 is demonstrated below using FIG.4 and FIG.5.
　まず、挿入工程では、外管１２にこの外管１２の内径よりも小さな外径の内管１１を挿入する。 First, in the insertion step, the inner tube 11 having an outer diameter smaller than the inner diameter of the outer tube 12 is inserted into the outer tube 12.
　次に、固定工程では、先端が鋭利でない棒等の有底孔を形成するのに適した凹み形成機具（図示せず）を、内管１１が挿入された外管１２に対し、当該外管１２の外面から中心に向けて外管１２の一部が凹むように押し込むことで、外管１２に複数の有底孔２２を形成する。この固定工程では、外管１２の有底孔２２の頂面２２ａが内管１１の外周に当接するまで、外管１２の一部を凹ませる。 Next, in the fixing step, a dent forming tool (not shown) suitable for forming a bottomed hole such as a rod with a sharp tip is not attached to the outer tube 12 into which the inner tube 11 is inserted. A plurality of bottomed holes 22 are formed in the outer tube 12 by pressing the outer tube 12 so that a part of the outer tube 12 is recessed from the outer surface of the tube 12 toward the center. In this fixing step, a part of the outer tube 12 is recessed until the top surface 22a of the bottomed hole 22 of the outer tube 12 contacts the outer periphery of the inner tube 11.
　このとき、少なくとも二重管７の直管部７Ａにおいては、例えば、図４（ｂ）に示されるように、複数の有底孔２２を当該外管１２の延長方向に沿って２列の列状となるように形成する。そして、例えば一方の外管１２の列を外管１２の径方向の一方（図面の上方）とし、他方の外管１２の列を外管１２の径方向の他方（図面の下方）として、２つの有底孔２２の列が対峙するようにする。 At this time, at least in the straight pipe portion 7A of the double pipe 7, for example, as shown in FIG. 4B, a plurality of bottomed holes 22 are arranged in two rows along the extending direction of the outer pipe 12. It forms so that it may become a shape. For example, one row of the outer tubes 12 is defined as one of the radial directions of the outer tube 12 (upward in the drawing), and the other row of the outer tubes 12 is defined as the other of the radial directions of the outer tube 12 (lower in the drawing). Two rows of bottomed holes 22 face each other.
　これにより、図４及び図５に示されるように、外管１２の径方向の一方（図面の上方）に配された有底孔２２の頂面２２ａと、外管１２の径方向の他方（図面の下方）に配された有底孔２２の頂面２２ａとが、内管１１の外面に断続的に当接する。従って、少なくとも二重管７の直管部７Ａにおいては、内管１１は、対峙する有底孔２２の頂面２２ａにより、内管１１の径方向の両側から挟まれるので、外管１２に固定される。 As a result, as shown in FIGS. 4 and 5, the top surface 22 a of the bottomed hole 22 disposed in one of the radial directions of the outer tube 12 (upward in the drawing) and the other radial direction of the outer tube 12 ( The top surface 22a of the bottomed hole 22 disposed in the lower part of the drawing intermittently contacts the outer surface of the inner tube 11. Therefore, at least in the straight pipe portion 7A of the double pipe 7, the inner pipe 11 is sandwiched from both sides in the radial direction of the inner pipe 11 by the top surface 22a of the opposed bottomed hole 22, and thus is fixed to the outer pipe 12. Is done.
　尚、外管１２の列状に配された各有底孔２２の間隔は均等であっても、不規則であっても良い。また、外管１２の径方向の一方に有する各有底孔２２と外管１２の径方向の他方に有する各有底孔２２とが配管の延長方向においてずれていても良い。更に、外管１２の外面の上方及び下方以外の部位にも、複数の有底孔２２が形成されていても良く、これらの有底孔２２は外管１２の周方向において不規則に点在していても良い。このような有底孔２２の配置としても、少なくとも二重管７の直管部７Ａにおいては、内管１１は、外管１２の有底孔２２の頂面２２ａにより、内管１１の径方向の少なくとも両側から挟まれたかたちとなるので、外管１２に固定することが可能である。また、外管１２の有底孔２２の頂面２２ａが内管１１の外面に複数箇所で当接するので、より確実に内管１１を外管１２に固定することができる。特に、有底孔２２を外管１２の周方向において３か所以上、かつ、外管１２の中心とそれぞれの有底孔２２とを結ぶ仮想線が交わることでなす角度を１８０°未満とすれば（図示せず）、内管１１を、３つ以上の有底孔２２の頂面２２ａによって挟持することができ、より安定的に内管１１を外管１２に固定することができる。また、内管１１を外管１２の略中央に位置すること（内管１１の軸方向の中心点を外管１２の軸方向の中心点の近傍に位置させること）ができるので、外管１２と内管１１との間に形成される高圧冷媒（第一の媒体）の流路３５を内管１１の周囲に形成することができ、高圧冷媒（第一の媒体）と低圧冷媒（第二の媒体）との熱交換の効率を向上できる。 It should be noted that the intervals between the bottomed holes 22 arranged in a row in the outer tube 12 may be uniform or irregular. Further, the bottomed holes 22 provided on one side in the radial direction of the outer tube 12 and the bottomed holes 22 provided on the other side in the radial direction of the outer tube 12 may be shifted in the extending direction of the pipe. Further, a plurality of bottomed holes 22 may be formed in portions other than the upper and lower sides of the outer surface of the outer tube 12, and these bottomed holes 22 are irregularly scattered in the circumferential direction of the outer tube 12. You may do it. Even in such an arrangement of the bottomed hole 22, at least in the straight pipe portion 7 </ b> A of the double pipe 7, the inner pipe 11 is arranged in the radial direction of the inner pipe 11 by the top surface 22 a of the bottomed hole 22 of the outer pipe 12. Since it is sandwiched from at least both sides, it can be fixed to the outer tube 12. Moreover, since the top surface 22a of the bottomed hole 22 of the outer tube 12 contacts the outer surface of the inner tube 11 at a plurality of locations, the inner tube 11 can be fixed to the outer tube 12 more reliably. In particular, the bottomed hole 22 has three or more locations in the circumferential direction of the outer tube 12, and the angle formed by the intersection of the virtual line connecting the center of the outer tube 12 and each bottomed hole 22 is less than 180 °. For example, the inner tube 11 can be sandwiched by the top surfaces 22 a of the three or more bottomed holes 22, and the inner tube 11 can be more stably fixed to the outer tube 12. Further, since the inner tube 11 can be positioned substantially at the center of the outer tube 12 (the axial center point of the inner tube 11 can be positioned in the vicinity of the axial center point of the outer tube 12), the outer tube 12 can be positioned. A flow path 35 of a high-pressure refrigerant (first medium) formed between the inner pipe 11 and the inner pipe 11 can be formed around the inner pipe 11, and a high-pressure refrigerant (first medium) and a low-pressure refrigerant (second medium) The efficiency of heat exchange with the medium) can be improved.
　実施例３及びその変形例の二重管７は、図６、図７及び図８に示されるように、いずれもアルミニウム製の内管１１と外管１２とを有する点、直管部７Ａ（図２）と曲げ部７Ｂ（図９）とを有したものとしても良い点、内管１１はいずれの箇所の断面も外周が円状をしても、あるいは図６（ｃ）、図７（ｂ）、図８（ｂ）の内管１１と同様に外周が螺旋状に凹んだ凹みを有しても良い点、内管１１が低圧側配管部８Ｂと接続され、外管１２が高圧側配管部８Ａと接続された構成である点で、実施例１、実施例２の二重管７と共通している。従って、実施例３及びその変形例の二重管７のうち実施例１や実施例２の二重管７と同様の構成や機能については、実施例１及び実施例２の二重管７と同じ符号を付すことでその説明を省略する。 As shown in FIGS. 6, 7, and 8, the double pipe 7 according to the third embodiment and the modified example has an aluminum inner pipe 11 and an outer pipe 12. 2) and a bent portion 7B (FIG. 9), the inner tube 11 may have a circular cross section at any point, or the outer periphery may be circular, or FIG. 6 (c) and FIG. b) As in the case of the inner tube 11 in FIG. 8B, the outer tube may have a recess with a spiral recess, the inner tube 11 is connected to the low-pressure side pipe 8B, and the outer tube 12 is connected to the high-pressure side. It is common with the double pipe 7 of Example 1 and Example 2 by the point connected to 8 A of piping parts. Therefore, about the structure and function similar to the double pipe 7 of Example 1 or Example 2 among the double pipes 7 of Example 3 and its modification, it is the same as that of the double pipe 7 of Example 1 and Example 2. The description is abbreviate | omitted by attaching | subjecting the same code | symbol.
　実施例３およびその変形例の二重管７の製造方法も、挿入工程と固定工程とがある。挿入工程については実施例１、実施例２と同じであるが、固定工程については実施例１、実施例２と異なっている。この二重管７の製造方法、特に実施例１や実施例２の二重管７の固定工程と異なる固定工程について、図６、図７及び図８を用いて以下に説明する。 The manufacturing method of the double pipe 7 of Example 3 and its modification also has an insertion process and a fixing process. The insertion process is the same as in Example 1 and Example 2, but the fixing process is different from Example 1 and Example 2. The manufacturing method of this double pipe 7, especially the fixing process different from the fixing process of the double pipe 7 of Example 1 or Example 2 is demonstrated below using FIG.6, FIG.7 and FIG.8.
　なお、実施例３の二重管７の内管１１は、図６（ｂ）及び図７（ａ）に示されるように、外周が円状で凹みの無い内管１１又は、図６（ｃ）及び図７（ｂ）に示されるように、外周が螺旋状に凹んだ凹み３１を有する内管１１が用いられる。凹み３１を有する構成の内管１１においては、凹み３１は、予め外管１２への挿入前に形成される。内管１１の凹み３１の形成は、例えば螺旋状の凹みを形成する螺旋状凹み形成装置を内管１１の外周に装着し、内管１１の周囲を回転させつつ内管１１の軸方向に変位させることにより、行われる。そして、内管１１の外周に螺旋状の凹み３１を形成することで、内管１１は、図６（ｃ）及び図７（ｂ）に示されるように、外周に凹部分３１ａと凸部分３１ｂとが内管１１の延長方向に沿って交互に形成された構成となる。螺旋状凹み形成装置は、例えば引用文献１の図７に示される公知のものであるので、その構成の説明を省略する。 As shown in FIGS. 6B and 7A, the inner tube 11 of the double tube 7 of the third embodiment has a circular outer periphery and has no recess, or FIG. ) And FIG. 7B, an inner tube 11 having a recess 31 whose outer periphery is recessed spirally is used. In the inner tube 11 having the recess 31, the recess 31 is formed in advance before being inserted into the outer tube 12. The formation of the recess 31 of the inner tube 11 is performed by, for example, mounting a spiral recess forming device that forms a spiral recess on the outer periphery of the inner tube 11 and rotating the periphery of the inner tube 11 in the axial direction of the inner tube 11. Is done. Then, by forming a spiral recess 31 on the outer periphery of the inner tube 11, the inner tube 11 has a concave portion 31a and a convex portion 31b on the outer periphery, as shown in FIGS. 6 (c) and 7 (b). Are alternately formed along the extending direction of the inner tube 11. Since the helical dent forming device is a known device shown in FIG. 7 of the cited document 1, for example, the description of the configuration is omitted.
　まず、挿入工程では、外管１２にこの外管１２の内径よりも小さな外径の内管１１を挿入する。内管１１が、外周が螺旋状に凹んだ凹み３１を有しても、あるいは有さなくとも、内管１１の外径は、外管１２の内径よりも小さい。 First, in the insertion step, the inner tube 11 having an outer diameter smaller than the inner diameter of the outer tube 12 is inserted into the outer tube 12. Even if the inner tube 11 has or does not have the recess 31 whose outer periphery is spirally recessed, the outer diameter of the inner tube 11 is smaller than the inner diameter of the outer tube 12.
　次に、固定工程では、例えば前記した螺旋状凹み形成装置（図示せず）を内管１１が挿入された外管１２の外周に装着し、外管１２の周囲を回転させつつ外管１２の軸方向に変位させることで、外管１２に螺旋状に凹んだ凹み２３を形成する。この固定工程では、外管１２の螺旋状に凹んだ凹み２３の頂面２３ａが内管１１の外面に連続して当接するように、外管１２の一部を凹ませる。 Next, in the fixing step, for example, the above-described helical dent forming device (not shown) is mounted on the outer periphery of the outer tube 12 into which the inner tube 11 is inserted, and the outer tube 12 is rotated while rotating around the outer tube 12. By displacing in the axial direction, the outer tube 12 is formed with a recess 23 that is spirally recessed. In this fixing step, a part of the outer tube 12 is recessed so that the top surface 23 a of the recess 23 that is recessed in the spiral shape of the outer tube 12 continuously contacts the outer surface of the inner tube 11.
　これにより、図６（ｂ）及び図７（ａ）に示されるように、外管１２の凹み２３の頂面２３ａが内管１１の外面に連続して当接し、内管１１は外管１２に固定される。しかも、外管１２の凹み２３の頂面２３ａ以外の内面と内管１１の外面とで、内管１１と外管１２との間に、螺旋状に延びる流路３５が形成され、この螺旋状の流路３５に沿って高圧冷媒（第一の媒体）が通流する。 Thereby, as shown in FIGS. 6B and 7A, the top surface 23a of the recess 23 of the outer tube 12 continuously contacts the outer surface of the inner tube 11, and the inner tube 11 is in contact with the outer tube 12. Fixed to. Moreover, a flow path 35 extending in a spiral shape is formed between the inner tube 11 and the outer tube 12 on the inner surface other than the top surface 23a of the recess 23 of the outer tube 12 and the outer surface of the inner tube 11, and this spiral shape is formed. The high-pressure refrigerant (first medium) flows along the flow path 35.
　外周が螺旋状に凹んだ凹み３１を有する内管１１を用いる場合にも、まず、外管１２にこの内管１１を挿入する挿入工程を行う。次に、固定工程では、例えば前記した螺旋状の凹み付け装置（図示せず）を内管１１が挿入された外管１２の外周に装着し、外管１２の周囲を回転させつつ外管１２の軸方向に変位させることで、外管１２に螺旋状に凹んだ凹み２３を形成する。この固定工程では、外管１２の螺旋状に凹んだ凹み２３の頂面２３ａが内管１１の外面に連続して当接するとともに、外管１２に形成する凹み２３のピッチと内管１１に予め設けた螺旋状の凹み３１のピッチとが略同一となるよう調整し、外管１２の螺旋状の凹み２３の頂面２３ａが内管１１の螺旋状の凸部分３１ｂに連続して当接するように、外管１２を螺旋状に凹ませる。 Even when using the inner tube 11 having the recess 31 whose outer periphery is spirally recessed, first, an insertion step of inserting the inner tube 11 into the outer tube 12 is performed. Next, in the fixing step, for example, the above-described helical recessing device (not shown) is mounted on the outer periphery of the outer tube 12 in which the inner tube 11 is inserted, and the outer tube 12 is rotated while rotating around the outer tube 12. Is formed in the outer tube 12 to form a recess 23 that is spirally recessed. In this fixing step, the top surface 23a of the recess 23 recessed in the spiral shape of the outer tube 12 continuously abuts on the outer surface of the inner tube 11, and the pitch of the recess 23 formed in the outer tube 12 and the inner tube 11 are preliminarily set. The pitch of the provided spiral recesses 31 is adjusted to be substantially the same so that the top surface 23a of the spiral recess 23 of the outer tube 12 continuously contacts the spiral convex portion 31b of the inner tube 11. The outer tube 12 is recessed in a spiral shape.
　これにより、図６（ｃ）及び図７（ｂ）に示されるように、外管１２の凹み２３の頂面２３ａが内管１１の凸部分３１ｂ（内管１１の外面）に連続して当接するので、内管１１は外管１２に固定される。しかも、外管１２の凹み２３の頂面２３ａ以外の内面と内管１１の凹部分３１ａの外面とで、内管１１と外管１２との間に、螺旋状に延びる流路３５が形成され、この螺旋状の流路３５に沿って高圧冷媒（第一の媒体）が通流する。 Accordingly, as shown in FIGS. 6C and 7B, the top surface 23a of the recess 23 of the outer tube 12 continuously contacts the convex portion 31b of the inner tube 11 (the outer surface of the inner tube 11). Because of the contact, the inner tube 11 is fixed to the outer tube 12. Moreover, a spirally extending flow path 35 is formed between the inner tube 11 and the outer tube 12 on the inner surface other than the top surface 23 a of the recess 23 of the outer tube 12 and the outer surface of the recessed portion 31 a of the inner tube 11. The high-pressure refrigerant (first medium) flows along the spiral flow path 35.
　もっとも、図８に示される実施例３の変形例に示されるように、外周が螺旋状に凹んだ凹み３１を有する内管１１を外管１２に挿入する場合であっても、外管１２に形成する螺旋状の凹み２３のピッチを内管１１の螺旋状の凹み３１の間隔より大きく（長く）する等して、内管１１の螺旋状の凹み３１の間隔と必ずしも同じにしなくても良い。ピッチを大きく（長く）することで外管１２に形成する螺旋状の凹み２３の加工の長さを短くでき、生産性を向上できる。逆に、外管１２に形成する螺旋状の凹み２３のピッチを内管１１の螺旋状の凹み３１の間隔より小さく（短く）する等してもよい。ピッチを小さく（短く）することで外管１２と内管１１との間を流れる第一の媒体は、内管１１の外面と接触する時間がより長く確保され、内管１１の内部を流れる第二の媒体との熱の交換が促進されて、二重管７の熱の交換性能を向上できる。 However, as shown in a modification of the third embodiment shown in FIG. 8, even when the inner tube 11 having the recess 31 whose outer periphery is spirally recessed is inserted into the outer tube 12, The pitch of the spiral recesses 23 to be formed is not necessarily the same as the interval of the spiral recesses 31 of the inner tube 11 by making the pitch larger (longer) than the interval of the spiral recesses 31 of the inner tube 11. . By making the pitch larger (longer), the processing length of the spiral recess 23 formed in the outer tube 12 can be shortened, and productivity can be improved. Conversely, the pitch of the spiral recesses 23 formed in the outer tube 12 may be made smaller (shorter) than the interval between the spiral recesses 31 of the inner tube 11. The first medium that flows between the outer tube 12 and the inner tube 11 by reducing (shortening) the pitch is secured for a longer period of time in contact with the outer surface of the inner tube 11, and the first medium that flows through the inner tube 11. Exchange of heat with the second medium is promoted, and the heat exchange performance of the double pipe 7 can be improved.
　このような実施例３の変形例の構成としても、図８（ｂ）に示されるように、外管１２の凹み２３の頂面２３ａが内管１１の複数の凸部分３１ｂのうちの一部の凸部分３１ｂに当接するようにすることで、内管１１は外管１２に固定される。また、外管１２の螺旋状の凹み２３や内管１１の螺旋状の凹み３１が、冷媒の通流のガイドとなって、高圧冷媒（第一の媒体）が、内管１１と外管１２との間を螺旋状に通流しやすくなる。 Also in the configuration of the modified example of Example 3 as described above, as shown in FIG. 8B, the top surface 23 a of the recess 23 of the outer tube 12 is a part of the plurality of convex portions 31 b of the inner tube 11. The inner tube 11 is fixed to the outer tube 12 by abutting against the convex portion 31b. In addition, the spiral recess 23 of the outer tube 12 and the spiral recess 31 of the inner tube 11 serve as a guide for refrigerant flow, and the high-pressure refrigerant (first medium) flows between the inner tube 11 and the outer tube 12. It becomes easy to flow in a spiral.
　実施例１、実施例２、実施例３及びその変形例として、二重管７の直管部７Ａを図示して、内管１１と外管１２との固定の方法を説明してきたが、二重管７が曲げ部７Ｂを有しても、これまで説明した挿入工程と固定工程とを用いて、内管１１と外管１２とを固定することができる。二重管７の曲げ部７Ｂにおける内管１１と外管１２との固定の方法を、有底孔２２を外管１２に形成する態様を例にして以下に説明する。なお、内管１１は、いずれの箇所の断面を見ても外周が円状である内管１１が例示されている。 As the first embodiment, the second embodiment, the third embodiment, and the modification thereof, the straight pipe portion 7A of the double pipe 7 is illustrated, and the method of fixing the inner pipe 11 and the outer pipe 12 has been described. Even if the heavy pipe 7 has the bent portion 7B, the inner pipe 11 and the outer pipe 12 can be fixed using the insertion process and the fixing process described so far. A method of fixing the inner tube 11 and the outer tube 12 in the bent portion 7B of the double tube 7 will be described below with an example in which the bottomed hole 22 is formed in the outer tube 12. In addition, as for the inner tube | pipe 11, even if it sees the cross section of any location, the outer tube | pipe 11 whose outer periphery is circular shape is illustrated.
　まず、外管１２にこの外管１２の内径よりも小さな外径の内管１１を挿入する挿入工程を行う。次に、図９（ａ）に示されるように、内管１１が挿入された外管１２を所定の角度に曲げる又は湾曲させる曲げ加工を行う。そして、有底孔２２を外管１２に形成する場合には、例えば、図９（ｂ）に示されるように、外管１２の内周側（所定の角度に曲げられ又は湾曲された部分の相対的に曲げ中心に近い側）の所定の箇所に有底孔２２を形成すると共に、外管１２の外周側（所定の角度に曲げられ又は湾曲された部分の相対的に曲げ中心から遠い側）であって前記外管１２の内周側の有底孔２２に対し外管１２の延長方向の両側となる所定の二箇所に有底孔２２を形成する固定工程を行う。この固定工程でも、外管１２の有底孔２２の頂面２２ａが内管１１の外周に当接するまで、外管１２の一部を凹ませて、有底孔２２を形成する。 First, an insertion step of inserting the inner tube 11 having an outer diameter smaller than the inner diameter of the outer tube 12 into the outer tube 12 is performed. Next, as shown in FIG. 9A, a bending process is performed in which the outer tube 12 in which the inner tube 11 is inserted is bent or curved at a predetermined angle. When the bottomed hole 22 is formed in the outer tube 12, for example, as shown in FIG. 9B, the inner peripheral side of the outer tube 12 (the portion bent or curved at a predetermined angle). A bottomed hole 22 is formed at a predetermined location on the side relatively closer to the bending center, and the outer peripheral side of the outer tube 12 (a side far from the bending center of a portion bent or curved at a predetermined angle) And a fixing step of forming the bottomed holes 22 at two predetermined positions on both sides in the extending direction of the outer tube 12 with respect to the bottomed holes 22 on the inner peripheral side of the outer tube 12 is performed. Even in this fixing step, the bottomed hole 22 is formed by denting a part of the outer tube 12 until the top surface 22a of the bottomed hole 22 of the outer tube 12 contacts the outer periphery of the inner tube 11.
　これにより、図９（ｂ）に示されるように、内管１１は外管１２の外周側と内周側とから複数の有底孔２２の頂面２２ａで支持されるので、内管１１が外管１２に固定される。従って、内管１１が挿入された外管１２が曲げ加工により曲げられ又は湾曲させられた後であっても、外管１２と内管１１とを固定工程により容易に固定することができる。 9B, the inner tube 11 is supported by the top surfaces 22a of the plurality of bottomed holes 22 from the outer peripheral side and the inner peripheral side of the outer tube 12, so that the inner tube 11 is It is fixed to the outer tube 12. Therefore, even after the outer tube 12 into which the inner tube 11 is inserted is bent or bent by a bending process, the outer tube 12 and the inner tube 11 can be easily fixed by the fixing process.
　なお、外管１２と内管１１とを固定する固定工程として、外管１２に有底孔２２を形成する態様を示したが、必ずしもこの態様に限定されない。図示しないが、外管１２を当該外管１２の延長方向に沿って凹ませて、凹み２１を形成する固定工程や、外管１２を螺旋状に凹ませて、凹み２３を形成する固定工程を、曲げ加工の後に行うようにしても良い。 In addition, although the aspect which forms the bottomed hole 22 in the outer pipe | tube 12 was shown as a fixing process which fixes the outer pipe | tube 12 and the inner pipe | tube 11, it is not necessarily limited to this aspect. Although not shown, a fixing step of forming the recess 21 by denting the outer tube 12 along the extending direction of the outer tube 12 and a fixing step of forming the recess 23 by spirally denting the outer tube 12. It may be performed after bending.
　また、図１０では、実施例２の変形例として、外管１２の有底孔２２の頂面２２ａが内管１１の外周よりも内側まで達するように、外管１２の一部を凹ませることで、内管１１にも凹み３２を形成して、有底孔２２の頂面２２ａと内管１１の凹み３２とを嵌合させた状態が示されている。これにより、外管１２と内管１１とを容易且つ強固に固定することができる。 In FIG. 10, as a modification of the second embodiment, a part of the outer tube 12 is recessed so that the top surface 22 a of the bottomed hole 22 of the outer tube 12 reaches the inner side of the outer periphery of the inner tube 11. Thus, a state is shown in which a recess 32 is formed also in the inner tube 11 and the top surface 22a of the bottomed hole 22 and the recess 32 of the inner tube 11 are fitted. Thereby, the outer tube | pipe 12 and the inner tube | pipe 11 can be fixed easily and firmly.
　なお、図示しないが、凹み２１の頂面２１ａが内管１１の外周よりも内側まで達するように、外管１２の一部を当該外管１２の延長方向に凹ませたり、凹み２３の頂面２３ａが内管１１の外周よりも内側まで達するように、外管１２を螺旋状に凹ませたりしても良い。これらの態様によっても、内管１１に凹み３２が形成されて、凹み３２と凹み２１の頂面２１ａ又は凹み３２と凹み２３の頂面２３ａとにより、外管１２と内管１１とが嵌合するので、外管１２と内管１１とを容易に、しかも強固に固定することができる。 Although not shown, a part of the outer tube 12 is recessed in the extending direction of the outer tube 12 such that the top surface 21 a of the recess 21 reaches the inner side of the outer periphery of the inner tube 11, or the top surface of the recess 23. The outer tube 12 may be helically recessed so that 23a reaches the inner side of the outer periphery of the inner tube 11. Also according to these aspects, the recess 32 is formed in the inner tube 11, and the outer tube 12 and the inner tube 11 are fitted by the recess 32 and the top surface 21 a of the recess 21 or the recess 32 and the top surface 23 a of the recess 23. Therefore, the outer tube 12 and the inner tube 11 can be easily and firmly fixed.
　また、これまで、外管１２の一部を内管１１へと押しこむ固定工程において、外管の延長方向に沿って凹ませる態様と、複数の有底孔が点在するように凹ませる態様と、螺旋状に凹ませる態様とをそれぞれ説明したが、必要に応じ、１つの二重管７に対して複数の態様を適用しても良い。 In addition, in the fixing process in which a part of the outer tube 12 is pushed into the inner tube 11 so far, a mode in which the outer tube 12 is recessed along the extending direction of the outer tube and a mode in which a plurality of bottomed holes are scattered are formed. In addition, although the spirally recessed mode has been described, a plurality of modes may be applied to one double pipe 7 as necessary.
　例えば、直管部７Ａでは螺旋状凹み形成装置を用いて螺旋状の凹み２３を形成する一方、所定の角度に曲げられ又は湾曲されて成る曲げ部７Ｂでは複数の有底孔２２、２２を形成する。このようにすれば、二重管７の形状に応じて、適切な固定方法を選択することができる。 For example, in the straight pipe portion 7A, a spiral recess 23 is formed by using a spiral recess forming device, while a plurality of bottomed holes 22 and 22 are formed in a bent portion 7B that is bent or curved at a predetermined angle. To do. In this way, an appropriate fixing method can be selected according to the shape of the double pipe 7.
　また、例えば、固定工程のうち、まず実施例２の変形例や図１０のように外管１２と内管１１とを強固に固定する工程を先に実施した後、次いで、他の凹ませる態様を実施してもよい。内管１１の位置を外管１２に対して早い段階で強固に固定できるので、その後の固定工程における意図しない外管１２と内管１１との位置のずれを防止することができる。 In addition, for example, in the fixing step, after first performing the step of firmly fixing the outer tube 12 and the inner tube 11 as shown in FIG. May be implemented. Since the position of the inner tube 11 can be firmly fixed to the outer tube 12 at an early stage, unintentional displacement between the outer tube 12 and the inner tube 11 in the subsequent fixing process can be prevented.
１　冷凍サイクル
７　二重管
７Ａ　直管部
７Ｂ　曲げ部
８　配管
８Ａ　高圧側配管部
８Ｂ　低圧側配管部
１１　内管
１２　外管
２１　外管の凹み
２１ａ　凹みの頂面
２２　外管の有底孔
２２ａ　有底孔の頂面
２３　外管の凹み
２３ａ　凹みの頂面
３１　内管の凹み
３２　内管の凹み DESCRIPTION OF SYMBOLS 1 Refrigeration cycle 7 Double pipe 7A Straight pipe part 7B Bending part 8 Piping 8A High pressure side piping part 8B Low pressure side piping part 11 Inner pipe 12 Outer pipe 21 Outer pipe dent 21a Depressed top surface 22 Bottom hole 22a of outer pipe Top surface 23 of the bottomed hole Depression 23a of the outer tube Top surface 31 of the recess Inner tube recess 32 Inner tube recess

Claims (9)

  1. 　車両に搭載される冷凍サイクルの内部熱交換器として用いられる二重管の製造方法であって、
    　外管に、前記外管の内径よりも外径が小さい内管を挿入する挿入工程と、
    　前記挿入工程の後に行う工程であって、前記外管の一部を前記内管の外周に当接するまで凹ませて前記外管と前記内管とを固定する固定工程と、
    　を有することを特徴とする二重管の製造方法。     A method of manufacturing a double pipe used as an internal heat exchanger of a refrigeration cycle mounted on a vehicle,
    An insertion step of inserting an inner tube having an outer diameter smaller than the inner diameter of the outer tube into the outer tube;
    A fixing step of fixing the outer tube and the inner tube by recessing a part of the outer tube until coming into contact with the outer periphery of the inner tube;
    A method for producing a double pipe, comprising:
  2. 　前記固定工程は、前記外管を、前記外管の延長方向に沿って凹ませる工程であることを特徴とする請求項１に記載の二重管の製造方法。 The method for manufacturing a double pipe according to claim 1, wherein the fixing step is a step of denting the outer pipe along an extending direction of the outer pipe.
  3. 　前記固定工程は、前記外管を、複数の有底孔が点在するように凹ませる工程であることを特徴とする請求項１に記載の二重管の製造方法。 The method for manufacturing a double tube according to claim 1, wherein the fixing step is a step of denting the outer tube so that a plurality of bottomed holes are scattered.
  4. 　前記固定工程は、前記外管を、螺旋状に凹ませる工程であることを特徴とする請求項１に記載の二重管の製造方法。 The method for manufacturing a double pipe according to claim 1, wherein the fixing step is a step of concavely forming the outer tube in a spiral shape.
  5. 　前記固定工程は、前記外管を螺旋状に凹ませるときに、前記外管の螺旋状に凹ませた部位の頂面を、連続して前記内管に当接させる工程であることを特徴とする請求項４に記載の二重管の製造方法。 The fixing step is a step of continuously abutting the top surface of the spirally recessed portion of the outer tube against the inner tube when the outer tube is recessed helically. The method for producing a double pipe according to claim 4.
  6. 　前記内管は、外周が螺旋状に凹んだ凹みを有することを特徴とする請求項１乃至請求項５のいずれかに記載の二重管の製造方法。 The method for manufacturing a double pipe according to any one of claims 1 to 5, wherein the inner pipe has a recess whose outer periphery is spirally recessed.
  7. 　前記挿入工程と前記固定工程との間に行われる工程として、前記内管が挿入された前記外管を所定の角度に曲げる又は湾曲させる曲げ加工を有し、
    　前記固定工程を、前記外管のうち前記曲げ加工により曲げられ又は湾曲させた部位に行うことを特徴とする請求項１乃至請求項６のいずれかに記載の二重管の製造方法。     As a step performed between the insertion step and the fixing step, a bending process for bending or bending the outer tube into which the inner tube is inserted at a predetermined angle,
    The method for manufacturing a double pipe according to any one of claims 1 to 6, wherein the fixing step is performed on a portion of the outer pipe bent or bent by the bending process.
  8. 　前記固定工程は、前記外管の一部が前記内管の外周よりも内側に達するまで、前記外管の一部を凹ませる工程であることを特徴とする請求項１乃至請求項７のいずれかに記載の二重管の製造方法。 8. The fixing step according to claim 1, wherein a part of the outer tube is recessed until a part of the outer tube reaches the inside of the outer periphery of the inner tube. A method for producing a double pipe according to claim 1.
  9. 　　前記外管と前記内管とは、アルミニウム製である
    　ことを特徴とする請求項１乃至請求項８のいずれかに記載の二重管の製造方法。     The method for manufacturing a double pipe according to any one of claims 1 to 8, wherein the outer pipe and the inner pipe are made of aluminum.
PCT/JP2016/075757 2015-09-04 2016-09-02 Method for manufacturing double pipe WO2017038962A1 (en)

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JP6651692B2 (en) * 2016-06-10 2020-02-19 株式会社ヴァレオジャパン Double tube internal heat exchanger
CN108344069A (en) * 2017-01-22 2018-07-31 大金工业株式会社 Electrical equipment cooling structure
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