JP2017160925A - Joint member and piping structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable reliable connection of a multilayer pipe even in a case of using a joint member mainly enabling fixation with external heating and crimping.SOLUTION: This invention relates to a joint member 3 having a cylindrical joint body 2 capable of being fixed to an end part of a resin pipe member 1 with external heating and crimping. The pipe member 1 is made into a multilayer pipe 11. The joint body 2 has, at its end part, an annular fitting groove part 12 capable of fitting an end part of the multilayer pipe 11. The annular fitting groove part 12 has an outer peripheral side fixation surface 13 capable of being fixed to an end part outer peripheral surface of the multilayer pipe 11, and an inner peripheral side fixation surface 14 capable of being fixed to an end part inner peripheral surface of the multilayer pipe 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a joint member and a piping structure.

  In order to connect a resin pipe member, a joint member is attached to the end of the pipe member (see, for example, Patent Document 1 and Patent Document 2).

  The joint member of Patent Document 1 is a joint member (so-called EF joint: EF is Electric Fusion) that is adapted to perform heat fusion by electrical internal heating.

  Moreover, the joint member of Patent Document 2 is a metal joint having a metal portion. Note that the joint member of Patent Document 2 also has a function of an EF joint.

  On the other hand, there is also known a joint member (so-called HF joint: HF is Heat Fusion) that can be fixed (heat fusion) to the end of the pipe member by external heating and pressure bonding.

JP 2001-31768 A JP-A-8-121669

  When the pipe member to which the joint member is attached is a multilayer pipe, when an ordinary HF joint is used to heat-seal between the outer peripheral surface of the multilayer pipe and the joint member, depending on the internal configuration of the multilayer pipe, an intermediate layer (for example, glass There is a risk of leakage from the interface of the fiber or aluminum layer, or there is a risk of the glass fiber of the intermediate layer flowing out into the fluid.

  Therefore, the connection of multilayer pipes, especially the connection of multilayer pipes for water supply and hot water use, is not the EF fusion or HF fusion that fuses the outer surface of the joint pipe and stops the water. Using a metal joint that stops the inner surface, a more reliable joining state was obtained.

  However, metal joints have the problem of being expensive and costly (than HF joints). In addition, the above-described EF joint has a problem that it takes time and effort to perform the construction, and a large construction space is required. Further, the metal joint is more costly than the EF joint, and also has problems such as corrosion due to deterioration over time.

  Accordingly, the main object of the present invention is to solve the above-described problems.

In order to solve the above problems, the present invention provides:
In the joint member having a tubular joint body that can be fixed by external heating and pressure bonding to the end of the resin pipe member,
The pipe member is a multilayer pipe,
The joint body has an annular fitting groove that can fit the end of the multilayer pipe at its end,
The annular fitting groove has an outer peripheral fixing surface that can be fixed to the outer peripheral surface of the end of the multilayer tube, and an inner peripheral fixing surface that can be fixed to the inner peripheral surface of the end of the multilayer tube. It is characterized by being.

  According to the present invention, according to the above configuration, the multilayer pipe can be reliably connected even when a joint member that can be fixed by external heating and pressure bonding is used.

It is sectional drawing which looked at the piping structure concerning this Embodiment from the side. It is sectional drawing of the coupling member of FIG. It is sectional drawing of an external heating apparatus. It is an end view of a high density polyethylene pipe. It is the block diagram which fractured | ruptured the high-density polyethylene pipe partially. It is the block diagram which fractured | ruptured the high heat-resistant polyethylene pipe partially. It is sectional drawing of a single side HF and a single side EF joint. It is sectional drawing of single side HF and a single side metal joint. It is sectional drawing of the integral pipe member for the same diameter pipe connection with a one-side HF joint. It is sectional drawing of the integral pipe member for different diameter pipe | tube connection with a one-side HF joint. FIG. 11A is a perspective view showing a state in which the multilayer pipe and the joint member are heated by the external heating device, FIG. 11B is a perspective view showing the multilayer pipe and the joint member removed from the external heating device, and FIG. FIG. 3 is a perspective view showing a state in which a heated multilayer pipe and a joint member are fitted.

Hereinafter, the present embodiment will be described in detail with reference to the drawings.
1 to 11 are for explaining this embodiment.

  <Configuration> The configuration will be described below.

  As shown in FIG. 1, a tubular joint body 2 (see FIG. 2) that can be fixed by external heating and pressure bonding to the end of a resin pipe member 1 (for connection of the pipe member 1). A joint member 3 is provided.

  Here, fixing by external heating and pressure bonding refers to bonding by heat fusion. Joining by heat fusion is a fixed state in which at least surface structures of resins melted and softened by heat are fused and integrated.

  “External heating and crimping is possible” (function) means “used for external heating and crimping” (use) or “for external heating and crimping” (purpose) In other words. These expressions all indicate the state before fixation.

  For the external heating, for example, an external heating device 5 as shown in FIG. 3 is used. The external heating device 5 has a double cylindrical tube mounting portion 7 on which both ends of the pipe member 1 can be mounted and a cylindrical shape on which both ends of the joint body 2 can be mounted on both surfaces of the heating device main body 6. The joint mounting portion 8 and the pipe mounting portion 7 and the joint mounting portion 8 (with the end portion of the pipe member 1 and the end portion of the joint main body 2 mounted (or fitted)). It can be electrically heated by a heater or the like provided in the interior.

  A crimping jig such as a clamp is used for the crimping. Further, after the pressure bonding, it is cooled by natural cooling or a cooling device.

  The joint body 2 is made of resin. The joint member 3 used for heat sealing is a so-called HF joint (HF is Heat Fusion). In this case, the joint body 2 is entirely composed of only a single resin.

  In addition to the basic or overall configuration as described above, this embodiment has the following configuration.

(1) The pipe member 1 is a multilayer pipe 11.
And the said coupling main body 2 has the cyclic | annular fitting groove part 12 which can fit the edge part of the said multilayer pipe | tube 11 in the edge part.
The annular fitting groove portion 12 can be fixed to the outer peripheral surface of the end portion of the multilayer tube 11, and the inner peripheral fixing surface 14 can be fixed to the inner peripheral surface of the end portion of the multilayer tube 11. And have.

  Here, the multilayer pipe 11 (composite pipe) is, for example, a resin composite pipe such as a high-density polyethylene pipe 21 as shown in FIGS. 4 and 5 or a high heat-resistant polyethylene pipe 31 (crosslinked polyethylene pipe) as shown in FIG. can do.

  As shown in FIGS. 4 and 5, the above-described high-density polyethylene pipe 21 is capable of circulating a liquid such as cold / hot water inside, and is configured outside the inner layer 23 through which the liquid can flow and the inner layer 23. An intermediate layer 24 having a thermal expansion / contraction rate smaller than that of the inner layer 23, an outer layer 25 configured to be outside the intermediate layer 24 and configured to be heat-sealable, and further outside the outer layer 25. An oxygen barrier layer 27 having an oxygen barrier property, and an adhesive layer 26 that is formed between the outer layer 25 and the oxygen barrier layer 27 and adheres the outer layer 25 and the oxygen barrier layer 27 to each other. Is done.

  The high-density polyethylene pipe 21 can be used as a cold / hot water pipe. This cold / hot water pipe is used, for example, for a hot water supply pipe of a hot water supply facility, a cold / hot water type air conditioning facility, or the like. The high density polyethylene pipe 21 is made of high density polyethylene as a material for the inner layer 23 and the outer layer 25. In addition, as a resin other than polyethylene, polypropylene, polybutene, or the like may be used.

The intermediate layer 24 is a fiber reinforced layer for suppressing thermal expansion and contraction to about half. Examples of the fiber reinforced layer include glass fibers, carbon fibers, and the like, or resins such as polyethylene containing fibers such as inorganic fibers such as wollastonite. Since the linear expansion coefficient of polyethylene is 10 × 10 ⁻⁵ / ° C. or more and the amount of thermal expansion is large, the thickness of the fiber reinforced layer and the amount of fiber added are 10 × 10 ⁻⁵ / ° C. More preferably, it is preferably adjusted to 5 × 10 ⁻⁵ / ° C. or less. Thermal expansion and contraction can be reduced by setting the linear expansion coefficient of the multilayer tube to the above value.

  Further, the ratio of the thickness of the intermediate layer 24 to the total thickness of the inner layer 23 and the outer layer 25 is 0.3 or more and 0.8 or less. By increasing the thickness of the intermediate layer 24 relative to the thickness of the entire high-density polyethylene pipe 21, the reliability (strength, dimensional stability, workability, etc.) of the high-density polyethylene pipe 21 can be increased. The intermediate layer 24 has a glass fiber content of 15 wt% or more and 45 wt% or less.

  In addition, it is preferable that resin used for the inner layer 23, the intermediate | middle layer 24, and the outer layer 25 contains the same resin material.

  The adhesive layer 26 may be anything as long as it can adhere the polyethylene constituting the outer layer 25 and the ethylene vinyl alcohol copolymer (EVOH) constituting the oxygen barrier layer 27. For example, the adhesive layer 26 is composed of maleic anhydride, graph and polyolefin. Resins can be used.

  The oxygen barrier layer 27 prevents rusting of the internal pipe (metal pipe) of the air conditioner connected to the cold / hot water pipe by preventing the permeation of oxygen. Examples of the oxygen barrier layer 27 include the aforementioned ethylene vinyl alcohol copolymer (EVOH) resin and aluminum. The oxygen barrier layer 27 is not limited to the outside of the outer layer 25, and can be provided inside the inner layer 23, between the inner layer 23 and the intermediate layer 24, between the intermediate layer 24 and the outer layer 25, and the like.

  Note that the adhesive layer 26 and the oxygen barrier layer 27 described above are removed during fixation (thermal fusion) by external heating and pressure bonding.

  Moreover, as shown in FIG. 6, the high heat-resistant polyethylene pipe 31 (crosslinked polyethylene pipe) described above is composed of an inner layer 33 made of high heat-resistant polyethylene that is flexible and excellent in corrosion resistance and heat resistance, and is formed outside the inner layer 33. An adhesive layer 34 (modified polyethylene layer) made of special adhesive polyethylene, which is formed between the aluminum reinforcing layer 35 excellent in strength and stretchability, and the inner layer 33 and the aluminum reinforcing layer 35 and bonds the inner layer 33 and the aluminum reinforcing layer 35 to each other. ) And an outer layer 37 made of high-density polyethylene formed outside the aluminum reinforcing layer 35, and a special adhesive property that is formed between the aluminum reinforcing layer 35 and the outer layer 37 and bonds the aluminum reinforcing layer 35 and the outer layer 37. And an adhesive layer 36 (modified polyethylene layer) made of polyethylene.

  As shown in FIG. 2, the fitting groove portion 12 is a groove (or a concave portion) serving as a welding and fixing portion. For example, the pipe member 1 (multilayer pipe 11) is provided so as to obtain a required welding (fixing) strength. It has a depth of about the diameter or more.

  Due to the fitting groove portion 12, the joint body 2 has a double cylinder structure in which an end portion includes an outer cylinder portion 16 and an inner cylinder portion 17. Further, the intermediate portion other than the end portion of the joint body 2 has a single-cylinder structure in which the outer cylinder portion 16 and the inner cylinder portion 17 are connected together by a connecting portion. A passage portion 18 that communicates with the inside of the pipe member 1 (multilayer pipe 11) is provided inside the joint body 2.

  The outer cylinder part 16 is made thicker than at least the pipe member 1 (multilayer pipe 11) so as to ensure a required bonding strength. The outer cylindrical portion 16 has an outer diameter whose outer peripheral surface is larger (constant) than the outer diameter of the pipe member 1 (multilayer pipe 11) by a thickness (constant), and an inner peripheral surface ( The outer peripheral fixing surface 13) has an inner diameter (inlet diameter) that is substantially the same as the outer diameter of the pipe member 1 (multilayer pipe 11).

  The inner cylinder part 17 is made thinner than the outer cylinder part 16 and the pipe member 1 (multilayer pipe 11) so that the inner diameter of the passage portion 18 communicating with the pipe member 1 (multilayer pipe 11) does not become too narrow. In addition, in the inner cylinder part 17, when the pipe member 1 (multilayer pipe | tube 11) is fitted, the channel | path part 18 turns to the near side of the coupling main body 2 so that the channel | path part 18 may become a substantially parallel cylindrical surface. A taper surface 19 that expands in diameter is provided. The tapered surface 19 is a surface that is continuous at a constant angle over the entire area of the end portion of the joint body 2 that is the inner cylindrical portion 17. In addition, in the intermediate part of the joint body 2, the passage part 18 is a parallel cylindrical surface.

  The outer peripheral side fixed surface 13 and the inner peripheral side fixed surface 14 are welding surfaces (or joint surfaces) provided inside the fitting groove 12, respectively.

(2) The outer peripheral side fixed surface 13 has a reduced-diameter tapered surface portion 41 that decreases in diameter toward the back of the joint body 2.
The inner peripheral side fixed surface 14 has a diameter-expanded tapered surface portion 42 that increases in diameter toward the back of the joint body 2.
The annular fitting groove 12 has a narrow shape.

  Here, the reduced-diameter tapered surface portion 41 is a continuous surface having a constant angle over the entire region, but may be a partial surface. Similarly, the enlarged diameter tapered surface portion 42 is a continuous surface having a constant angle over the entire region, but may be a partial surface. Further, the reduced diameter tapered surface portion 41 and the enlarged diameter tapered surface portion 42 may be multi-staged. Multi-stage shapes include those having a plurality of tapered surfaces with different angles, those having a parallel portion between the tapered surfaces, and combinations thereof. Most preferably, both the reduced diameter tapered surface portion 41 and the expanded diameter tapered surface portion 42 have both, but structurally, at least one of the reduced diameter tapered surface portion 41 and the expanded diameter tapered surface portion 42 is present. It is also possible to have only one. The inner narrow shape is a shape in which the inner portion is narrower than the entrance portion of the fitting groove portion 12.

  (3) It is good also considering the back part of the said fitting groove part 12 where the said outer peripheral side fixed surface 13 and the inner peripheral side fixed surface 14 cross (R shape part 51).

  Here, the round shape portion 51 has a diameter substantially equal to the wall thickness of the pipe member 1 (multilayer pipe 11), or a substantially semicircular shape having a diameter smaller than that of the fitting groove portion 12 having a narrow shape. It is assumed to have a shape. It is preferable that the fitting groove portion 12 be slightly narrower than the wall thickness of the pipe member 1 (multilayer pipe 11) because the crimping force at the time of fitting can be increased.

  (4) A through-hole 55 extending toward the outer peripheral surface of the joint body 2 may be provided in the back of the fitting groove 12.

  Here, the through hole 55 extends toward the radial direction of the joint body 2 with respect to the outer cylinder portion 16 and the like. One or more through holes 55 are provided in the circumferential direction of the joint body 2.

  (5) A protrusion 61 that extends outward from the inner peripheral fixing surface 14 and protrudes beyond the end of the joint body 2 may be provided on the inner peripheral portion of the fitting groove 12.

  Here, the protruding portion 61 is configured by making the end portion of the inner cylinder portion 17 longer than the end portion of the outer cylinder portion 16. The protruding portion 61 has a length substantially the same as or longer than the thickness of the pipe member 1 (multilayer pipe 11). In this case, the protrusion 61 has a tapered surface whose outer peripheral surface is smoothly continuous with the enlarged diameter tapered surface portion 42. Further, the protrusion 61 has a tapered surface whose inner peripheral surface is smoothly continuous with the tapered surface 19.

  In addition, in the case of FIG. 2, the fitting groove part 12 mentioned above is each provided with respect to the both ends of the cylindrical coupling main body 2 (both-side HF coupling). The joint member 3 has a cylindrical joint body 2 as a straight pipe portion, for example, a socket capable of fixing pipe members 1 (multilayer pipes 11) having the same diameter, or pipe members 1 having different diameters (multilayer pipes 11). ) It may be a reducer that can fix each other.

  Moreover, the cylindrical joint main body 2 is good also as a curved pipe part etc. which bent in 45 degree | times, 90 degree | times, curve shape etc., for example.

  Furthermore, the cylindrical joint body 2 may be a branch joint whose middle portion branches at an angle of 45 degrees or 90 degrees, for example. In this case, the above-described fitting groove portion 12 and the like can be provided also for the opening portion (receiving portion) of the branch portion.

  On the other hand, as shown in FIG. 7, the fitting groove portion 12 and the like described above are provided on one end side of the joint body 2, and the coil 64 is configured so that electrical internal heating is possible on the other end side of the joint body 2. Etc. may be embedded (one-side HF, one-side EF joint). In the figure, a configuration such as a terminal for supplying power to the coil 64 is omitted.

  Further, as shown in FIG. 8, the fitting groove portion 12 and the like described above may be provided on one end side of the joint body 2, and a metal joint member 65 may be embedded on the other end side of the joint body 2 (one side HF). , One side metal fitting).

  Alternatively, as shown in FIG. 9, one end of the pipe member 1 (same diameter pipe 1 a) may be enlarged and the above-described fitting groove 12 or the like may be integrally provided. Integrated pipe member for diameter pipe connection).

  Similarly, as shown in FIG. 10, one end of the pipe member 1 (different diameter pipe 1 b) may be expanded and the above-described fitting groove 12 or the like may be provided integrally (with one-side HF joint). Integrated pipe member for connecting different diameter pipes).

  (6) Then, as shown in FIG. 1, a pipe structure 71 may be provided in which the joint member 3 is fixed in advance to the end of the multilayer pipe 11.

  Here, the piping structure 71 is shipped as a product in which the joint member 3 and the multilayer pipe 11 made separately are heat-sealed at the factory, and the joint member 3 and the multilayer pipe 11 are integrally fixed. This is what is delivered (separate type joint pipe 75).

  <Operation> The operation of this embodiment will be described below.

  When the joint member 3 (the joint body 2) is fixed to the end of the resin pipe member 1 (multilayer pipe 11) by external heating and pressure bonding (thermal fusion), as shown in FIG. In the external heating device 5, the end of the pipe member 1 is mounted on the double cylindrical tube mounting portion 7 provided on one surface of the heating device main body 6, and the cylindrical joint mounted on the opposite surface is mounted. By attaching the end of the joint body 2 to the part 8 and electrically heating the pipe mounting part 7 and the joint mounting part 8, the end part of the pipe member 1 and the end part of the joint body 2 are melted and softened simultaneously. . In addition, you may perform the heating of the edge part of the pipe member 1 and the edge part of the coupling main body 2 separately.

  When the end of the pipe member 1 and the end of the joint body 2 are melted and softened, they are detached from the external heating device 5 and are fitted and crimped together as shown in order in FIGS. 11 (b) and 11 (c). . At this time, it is preferable to use a crimping jig such as a clamp for holding the crimped state. Moreover, after crimping, it is cooled by natural cooling or a cooling device. After cooling, the fixing is completed by removing a crimping jig such as a clamp. For fixing the pipe member 1 and the joint body 2, since only the external heating device 5 and a crimping jig are used, a particularly large construction space is not required.

  The fixed state thus obtained is that the outer peripheral surface of the end portion and the inner peripheral surface of the end portion of the pipe member 1 (multilayer pipe 11) are simultaneously fixed to the joint member 3.

  <Effect> According to this embodiment, the following effects can be obtained.

  (Effect 1) The joint member 3 of this embodiment is configured such that an externally heated tubular joint body 2 and the end of the pipe member 1 can be pressure-bonded and fixed (heat fusion).

  Here, when the pipe member 1 is the multi-layer pipe 11, when the outer peripheral surface of the multi-layer pipe 11 and the inner peripheral surface of the joint body 2 are heat-sealed using a normal HF joint, the internal configuration of the multi-layer pipe 11 is obtained. Depending on the case, the fixed state may be insufficient, which may cause leakage. Note that the internal structure of the multilayer tube 11 that is likely to be insufficiently fixed is, for example, an intermediate layer made of a material that cannot be heat-sealed (for example, the intermediate layer 24 (glass fiber) of the high-density polyethylene tube 21 in FIGS. 4 and 5). Or, the ratio of the aluminum reinforcing layer 35 of the high heat-resistant polyethylene pipe 31 in FIG. 6 is larger than the outer layers 25 and 37 to be heat-sealed.

  Therefore, an annular fitting groove 12 capable of fitting the end of the multilayer tube 11 is provided at the end of the joint body 2. And the outer peripheral side fixed surface 13 which can fix the cyclic | annular fitting groove part 12 with respect to the outer peripheral surface of the edge part of the multilayer tube 11, and the inner peripheral side fixed surface which can be fixed with respect to the inner peripheral surface of the edge part of the multilayer tube 11 14. Thereby, as for the multilayer tube 11, both surfaces of an end outer peripheral surface and an end inner peripheral surface are respectively fixed with respect to both surfaces of the outer peripheral side fixed surface 13 and the inner peripheral side fixed surface 14 of the fitting groove part 12. become. As a result, an internal / external double fixed state can be obtained between the multilayer pipe 11 and the joint body 2, so that the fixation is sufficient, and leakage from the fixed portion between the multilayer pipe 11 and the joint body 2 is prevented. It becomes possible to prevent reliably. Therefore, it is possible to use the joint member 3 (HF joint) that performs heat fusion by external heating and pressure bonding for the connection of the multilayer tube 11.

  In addition, the joint member 3 (HF joint) used for performing heat fusion by external heating and pressure bonding is composed entirely or at least the periphery of the fitting groove portion 12 with only a single resin, and is integrally molded. Therefore, it can be manufactured at a lower cost than metal joints and EF joints, and the cost can be reduced (cost reduction of about 30% to 50%). For example, it is easy and free to increase the strength by increasing the thickness of the joint member 3 (the outer cylinder portion 16).

  In addition, the joint member 3 (HF) of this embodiment can be obtained by only adding or changing a part of the insert for forming the inner peripheral side fixing surface 14 and the inner cylinder part 17 with respect to the mold forming the existing HF joint. (Joint) can be formed (or manufactured). Therefore, conversion from the existing HF joint to the joint member 3 of this embodiment and conversion from the joint member 3 of this embodiment to the existing HF joint can be easily performed.

  Further, the joint member 3 (HF joint) that performs heat fusion by external heating and pressure bonding does not require a pretreatment for connecting the multilayer tube 11 or simplifies the pretreatment. Construction in a shorter time is possible than EF joints that require pretreatment.

  (Effect 2) By having the diameter-reduced taper surface part 41 in the outer peripheral side fixed surface 13, and having the diameter-expanded taper surface part 42 in the inner peripheral side fixed surface 14, the annular fitting groove part 12 becomes narrow. It became shape. When the multilayer tube 11 is inserted into the joint body 2 by the narrow fitting groove 12 having the reduced diameter tapered surface portion 41 and the expanded diameter tapered surface portion 42, the inner and outer peripheral surfaces have a higher pressure bonding force. A reliable fitting state and fixed state can be obtained.

  (Effect 3) The back part of the fitting groove part 12 where the outer peripheral side fixing surface 13 and the inner peripheral side fixing surface 14 intersect is rounded. Thus, when the end of the multilayer tube 11 is fitted into the fitting groove 12, the stress is prevented from concentrating in the inner part of the fitting groove 12, and the inner part of the fitting groove 12 is affected by the stress concentration. Can prevent it from becoming vulnerable.

  (Effect 4) A through hole 55 extending toward the outer peripheral surface of the joint body 2 is provided in the back of the fitting groove 12. The through-hole 55 allows the air inside the fitting groove 12 to escape to the outside when the end of the multilayer tube 11 is fitted into the fitting groove 12 of the joint body 2, so that the fitting groove 12 It is possible to fit the end of the multilayer tube 11 up to the back of the tube, and to make it difficult or difficult to form a cavity or void in the back.

  Further, it is possible to check the internal fusion state through the through hole 55 or to estimate the internal fusion state from the state of the resin that has entered the through hole 55.

  (Effect 5) Protruding portions 61 that extend outward from the inner peripheral fixing surface 14 and protrude beyond the end portions of the joint body 2 are provided on the inner peripheral portion of the fitting groove portion 12. The protrusion 61 facilitates centering of the multilayer tube 11 when the end of the multilayer tube 11 is fitted into the fitting groove 12 of the joint body 2.

  (Effect 6) The above-described joint member 3 was fixed to the end of the multilayer pipe 11 to configure the piping structure 71. Thereby, the same effect as the above can be obtained. Further, by making the multilayer tube 11 and the joint member 3 separately and fixing them, the structure can be simplified and the manufacturing can be facilitated as compared with the case where the joint member 3 is integrally provided at the end of the multilayer tube 11 in advance. Etc.

  Furthermore, by commercializing the joint member 3 that has been fixed to the end of the multilayer pipe 11 in advance, it is possible to ship and deliver the joint member 3 with respect to the multilayer pipe 11 being strictly controlled at the factory. Thus, the reliability of the connection portion between the multilayer pipe 11 and the joint member 3 can be enhanced. Furthermore, in the piping structure 71 such as the cold / hot water type air conditioning equipment, the handling of the multilayer pipe 11 and the structure around the fixed portion of the joint member 3 with respect to the multilayer pipe 11 tend to be complicated. This makes it possible to ship and deliver the product with a simplified structure so that construction at the site is easy.

  As mentioned above, although embodiment of this invention has been explained in full detail with drawing, embodiment is only an illustration of this invention. Therefore, the present invention is not limited only to the configuration of the embodiment, and it goes without saying that design changes and the like within a scope not departing from the gist of the present invention are included in the present invention. Further, for example, when each embodiment includes a plurality of configurations, it is a matter of course that possible combinations of these configurations are included even if not specifically described. In addition, in the case where a plurality of examples and modifications are disclosed in the embodiment as those of the present invention, possible combinations of combinations extending over these are included even if not specifically described. Of course. Further, the configuration depicted in the drawings is of course included even if not particularly described. Further, when there is a term of “etc.”, it is used in the sense that the equivalent is included. In addition, when there are terms such as “almost”, “about”, “degree”, etc., they are used in the sense that they include those in the range and accuracy recognized by common sense.

DESCRIPTION OF SYMBOLS 1 Pipe member 2 Joint body 3 Joint member 11 Multilayer pipe 12 Fitting groove part 13 Outer peripheral side fixed surface 14 Inner peripheral side fixed surface 41 Reduced diameter taper surface part 42 Expanded diameter taper surface part 55 Through hole 61 Protrusion part 71 Piping structure

Claims (6)

In the joint member having a tubular joint body that can be fixed by external heating and pressure bonding to the end of the resin pipe member,
The pipe member is a multilayer pipe,
The joint body has an annular fitting groove that can fit the end of the multilayer pipe at its end,
The annular fitting groove has an outer peripheral fixing surface that can be fixed to the outer peripheral surface of the end of the multilayer tube, and an inner peripheral fixing surface that can be fixed to the inner peripheral surface of the end of the multilayer tube. A joint member characterized by comprising: The joint member according to claim 1,
The outer peripheral side fixed surface has a reduced diameter tapered surface portion that reduces the diameter toward the back of the joint body,
The inner peripheral side fixed surface has a diameter-increased tapered surface portion that expands toward the back of the joint body,
The annular fitting groove has a narrow shape, and is a joint member. In the joint member according to claim 1 or 2,
A joint member, wherein a back portion of the fitting groove portion where the outer peripheral side fixing surface and the inner peripheral side fixing surface intersect is formed in a round shape. In the joint member according to any one of claims 1 to 3,
A joint member, characterized in that a through hole extending toward the outer peripheral surface of the joint body is provided in the inner part of the fitting groove. The joint member according to any one of claims 1 to 4,
A joint member characterized in that a projecting portion that extends outward from the inner peripheral side fixed surface and projects beyond the end of the joint body is provided on an inner peripheral portion of the fitting groove.   A piping structure in which the joint member according to any one of claims 1 to 5 is fixed to an end portion of a multilayer pipe.