JP7458193B2 - Composite pipe and composite pipe connection structure - Google Patents

Description

The present invention relates to a composite pipe and a composite pipe connection structure.

A method is disclosed for molding a composite tube in which the outer layer is a corrugated tube, the intermediate layer is made of foamed resin, and the inner layer is made of polyolefin resin in one line (co-extrusion) (Patent Document 1) reference).

Japanese Patent Application Publication No. 2004-322583

However, in the conventional example described above, the intermediate layer is made of foamed resin and the inner layer is also made of resin. When the intermediate layer is formed by melting and foaming the resin on the outside of the inner tube by extrusion molding, the heat melts the outer surface of the inner layer, and after cooling, the intermediate layer tends to adhere to the outer surface of the inner layer.

On the other hand, when connecting a composite pipe to a pipe joint, the corrugated pipe and intermediate layer are generally shrunk in the axial direction of the inner layer and peeled off from the inner pipe to expose the inner layer. At this time, we believe that if the intermediate layer adheres to the outer circumferential surface of the inner layer, the corrugated pipe and intermediate layer cannot be easily peeled off, making it difficult to connect the inner layer to the pipe joint. It will be done.

In addition, in order to suppress adhesion between the intermediate layer and the inner layer, it is possible to cool the foam-molded intermediate layer and then insert the inner layer into the intermediate layer, but this increases the number of steps. It becomes difficult to manufacture on a line.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to manufacture a composite tube in which a corrugated tube and an intermediate layer can be easily peeled off from an inner tube on one line.

The composite pipe according to the first aspect is tubular, and has a bellows-like shape in which annular peaks that are convex toward the outside in the radial direction and annular valleys that are concave on the outside in the radial direction are alternately formed in the axial direction. a corrugated pipe that can be shortened in the axial direction at the peaks and troughs; an intermediate layer disposed inside the corrugated pipe; and an intermediate layer disposed inside the intermediate layer, the outer peripheral surface of which is the intermediate layer. and an inner tube made of a material that is difficult to adhere to.

In this composite tube, the outer peripheral surface of the inner tube is made of a material that does not easily adhere to the intermediate layer, so even if the intermediate layer is formed by extrusion molding by melting and foaming the resin on the outside of the inner tube, the intermediate layer is difficult to adhere to the outer circumferential surface of the inner tube. Therefore, when connecting the composite pipe to the pipe joint, the corrugated pipe and the intermediate layer can be easily shrunk in the axial direction of the inner pipe and peeled off from the inner pipe. Further, when manufacturing the composite pipe, the step of cooling the foam-molded intermediate layer and then inserting the inner layer into the intermediate layer becomes unnecessary.

In a second aspect, in the composite tube according to the first aspect, the inner tube has at least a two-layer structure.

In this composite tube, the inner tube has at least a two-layer structure, so while the material for the inner layer that does not constitute the outer circumferential surface of the inner tube can be selected to some extent, the adhesion between the intermediate layer and the outer circumferential surface of the inner tube can be improved. can be suppressed.

In the third aspect, in the compound pipe according to the first or second aspect, the outer circumferential surface of the inner pipe is made of metal.

In this composite pipe, the outer circumferential surface of the inner pipe is made of metal, so the melting point of the outer circumferential surface is higher than the temperature at which the intermediate layer is formed by melting and foaming the resin on the outside of the inner pipe by extrusion molding. This makes it possible to suppress adhesion between the intermediate layer and the outer circumferential surface of the inner pipe.

In a fourth aspect, in the composite tube according to the first aspect or the second aspect, the outer circumferential surface of the inner tube is made of fluororesin.

In this composite tube, the outer circumferential surface of the inner tube is made of fluororesin and is slippery, so that adhesion between the intermediate layer and the outer circumferential surface of the inner tube can be suppressed. Furthermore, when connecting the composite pipe to a pipe joint, it is easy to peel off the corrugated pipe and the intermediate layer from the inner pipe to expose the inner pipe.

In a fifth aspect, in the composite tube according to any one of the first to fourth aspects, the intermediate layer is made of a material having a lower melting point than the material of the outer peripheral surface of the inner tube.

In this composite tube, the intermediate layer is made of a material with a lower melting point than the material on the outer circumferential surface of the inner tube, so when forming the intermediate layer by melting and foaming the resin on the outside of the inner tube by extrusion molding, , the outer peripheral surface of the inner tube does not melt. Therefore, adhesion between the intermediate layer and the outer circumferential surface of the inner tube can be suppressed.

A composite pipe connection structure according to a sixth aspect includes the composite pipe according to the third aspect, a cylindrical core material inserted into the inner tube of the composite pipe, and a cylindrical core material disposed on the outer peripheral part of the core material. A lock claw; and a pipe joint having a lock claw.

In this composite tube connection structure, by inserting the core material into the inner tube, the locking claw contacts the inner circumference of the inner tube, so if the inner tube tries to come out, the claw will This prevents the inner tube from coming off. Furthermore, since the outer circumferential surface of the inner tube is made of metal, expansion of the diameter of the inner tube when the lock pawl is caught on the inner circumference of the inner tube is suppressed. Therefore, the inner tube can be held more reliably by the lock claw.

A seventh aspect is the composite pipe connection structure according to the sixth aspect, in which the locking pawl is provided in an annular portion formed of a resin material and in contact with the outer circumferential portion, and in the annular portion, the locking pawl is provided in the annular portion and is provided in the inner tube. It consists of a metal claw that contacts the inner circumference.

In this composite pipe connection structure, the annular part is made of a resin material that is more easily deformed than metal, so it is easier to expand the diameter than when the annular part is made of metal, and the metal claws It becomes easier to bite into the inner periphery of the composite pipe, and the effect of preventing the composite pipe from coming off can be enhanced.

According to the present invention, a composite tube whose corrugated tube and intermediate layer can be easily peeled off from the inner tube can be manufactured on one production line.

1 is a cross-sectional view showing a composite pipe connection structure according to an embodiment of the present invention. FIG. 3 is a perspective view showing a lock claw of the pipe joint. FIG. 2 is a partially cutaway perspective view showing a lock claw of a pipe joint. FIG. 11 is a perspective view showing a locking claw according to a modified example. It is a sectional view showing a part of a compound pipe concerning a modification. FIG. 1 is a perspective view showing a composite pipe according to the present embodiment. It is a half sectional view showing a composite pipe concerning this embodiment. FIG. 2 is a half-sectional view showing an exposed end of the inner tube of the composite tube according to the present embodiment. FIG. 2 is a perspective view showing a state in which the end of the inner tube of the composite tube according to the present embodiment is exposed.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated based on drawing.

(Composite pipe connection structure)
1 to 3, a composite pipe connection structure 12 including a composite pipe 14 according to this embodiment will be described.

As shown in FIG. 1, the composite pipe connection structure 12 includes a pipe joint 10 and a composite pipe 14. The pipe fitting 10 and the composite pipe 14 can be suitably used for water supply or hot water supply, as an example, but they can also be used for any fluid, including liquids other than water or gases. .

The pipe fitting 10 is configured to include a core material 28 and a locking claw 20. Specifically, the pipe fitting 10 is configured to include a fitting body 16 on which the core material 28 is formed, a water-stopping member 18, and a locking claw 20. The pipe fitting 10 is formed in a straight line and is symmetrical about the center in the longitudinal direction. The pipe fitting 10 may be asymmetrical, and may be configured in any shape, such as an approximately L-shape, an approximately T-shape, or an approximately cross shape.

The joint body 16 of this embodiment is a straight pipe shape, with a flow path 22 penetrating the axial center. A flange 24 that protrudes radially outward (in the direction of arrow R) is formed in the longitudinal center of the joint body 16. A core material 28 that is inserted into the composite pipe 14 is formed on both sides of the flange 24 of the joint body 16.

A first groove 30 is formed on the tip side of the outer periphery of the core material 28. The first groove 30 accommodates the water-stopping member 18. The water-stopping member 18 is an O-ring or other member made of an elastic body. The first groove 30 has a groove bottom formed with a constant diameter along the axial direction.

Further, a second groove 32 is formed on the flange 24 side of the first groove 30 on the outer periphery of the core material 28 . A lock pawl 20, which will be described later, is accommodated in the second groove 32. The second groove 32 is formed to have a longer length in the axial direction than the annular portion 36 of the lock pawl 20 . A constant diameter portion 32A having a constant diameter is formed at the bottom of the second groove 32 on the flange 24 side. A tapered inclined surface 32B is formed on the tip end side of the core material 28 (opposite side to the flange 24) at the groove bottom of the second groove 32, the diameter of the groove bottom increasing toward the tip side of the core material 28. has been done. A stopper 34 is provided between the core material 28 and the flange 24 in the joint body 16. This stopper 34 is a portion against which the end of the composite tube 14 abuts, and is formed to have a larger diameter than the core material 28.

(lock claw)
As shown in FIGS. 2(A) and 2(B), the lock claw 20 of this embodiment is arranged in the outer peripheral portion of the core material 28, specifically, in the second groove 32. The overall shape of this lock claw 20 is approximately C-shaped. In other words, the lock pawl 20 is formed in an annular shape that is not continuous in the circumferential direction, and is partially spaced apart, for example. The lock pawl 20 has a substantially C-shaped overall shape, so that it can be easily elastically deformed (diameter expansion and diameter contraction) in the radial direction. Therefore, when the lock claw 20 is accommodated in the second groove 32 of the core material 28, the diameter of the lock claw 20 can be expanded so that the inner diameter is larger than the diameter of the core material 28. It can be easily accommodated in the groove 32 of No. 2.

The lock pawl 20 includes an annular portion 36 made of a resin material and in contact with the outer periphery, and a metal pawl 40 provided on the annular portion 36 and in contact with the inner periphery of the inner tube 42 in the composite tube 14. It is configured. The annular portion 36 is formed in a substantially C-shape. This annular portion 36 has a slit 38 extending along the axis toward the opposite end at the end on the tip side of the core material (in the direction of arrow F in the drawing) when the lock claw 20 is attached to the core material 28. A plurality of them are formed at intervals in the circumferential direction. In this embodiment, slits 38 are formed at five locations.

Metal claws 40 protrude from the outer peripheral portion of the annular portion 36 between the slits 38 and between the slits 38 and the circumferential end portion 36E of the annular portion 36. The claws 40 are each independently and integrally embedded in the resin of the annular portion 36, and a portion thereof protrudes from the outer periphery of the annular portion 36. The claws 40 can be formed, for example, by press-molding a metal plate or the like. Further, the claw 40 can be integrated with the resin material when the annular portion 36 is molded using the resin material.

Hereinafter, in this specification, the portion of the claw 40 that protrudes from the outer circumference of the annular portion 36 will be referred to as a biting portion 40A.

The biting portion 40A is inclined in the radial direction of the annular portion 36 on the side opposite to the distal end side of the core material 28, in other words, in the direction in which the composite tube 14 is fitted into the core material 28.

As an example, the outer diameter of the annular portion 36 is determined so that the annular portion 36 does not protrude beyond the outer surface of the core material 28 when the lock claw 20 is accommodated in the second groove 32 of the core material 28. Note that when the lock claw 20 is accommodated in the second groove 32, the annular portion 36 contacts the bottom surface of the second groove 32 (the outer peripheral portion of the core material 28).

On the other hand, as shown in FIG. 3, when the locking claw 20 is accommodated in the second groove 32, the diameter φ of the imaginary circle FC passing through the tip of each biting portion 40A is set to be larger than the outer diameter D of the core material 28 (see FIG. 1) and to an outer diameter that contacts the inner circumference of the inner pipe 42 in the composite pipe 14.

(composite pipe)
6 to 9, the composite pipe 14 according to the present embodiment is a composite pipe with a multilayer structure, and includes a corrugated pipe 44 as a coating layer, an intermediate layer 46, and an inner pipe 42. .

The corrugated pipe 44 has a tubular shape, and an annular peak portion 44A that is convex toward the outside in the radial direction and an annular trough portion 44B that is concave on the outside in the radial direction alternate in the axial direction (direction of the axis S), for example. It is continuously formed into a bellows shape, and can be shortened in the axial direction at the peaks 44A and troughs 44B. The corrugated pipe 44 has a cylindrical shape that is one size larger than the outer diameter of the inner pipe 42, and is disposed in the inner pipe 42 with an intermediate layer 46 interposed therebetween. The corrugated pipe 44 is a resin pipe formed using a resin material. Examples of the resin material include polyolefins such as polybutene, polyethylene, polypropylene, and crosslinked polyethylene, and vinyl chloride. Only one type of resin may be used or two or more types may be used in combination.

The intermediate layer 46 is disposed inside the corrugated pipe 44, specifically between the inner pipe 42 and the corrugated pipe 44, and is made of, for example, foamed resin. The inner peripheral surface of the intermediate layer 46 is flat, and covers the outer periphery of the inner tube 42 while being in full contact with the outer periphery of the inner tube 42 . Note that "contact on the entire surface" herein does not necessarily mean that all parts are in close contact with each other, but means that substantially the entire surface is in contact. Therefore, this includes a case where a part of the intermediate layer 46 is separated from the inner tube 42. Further, the intermediate layer 46 does not need to be made of foamed resin.

The intermediate layer 46 is made of a material with a lower melting point than the material of the outermost layer 48 of the inner tube 42, which will be described later. The outermost layer 48 is an example of the outer circumferential surface of the inner tube 42. Examples of resins for the intermediate layer 46 include polyurethane, polystyrene, polyethylene, polypropylene, and ethylene propylene diene rubber, as well as mixtures of these resins. Among the resins, polyurethane is preferred. The intermediate layer 46 is preferably a layer containing polyurethane as a main component (i.e., a porous urethane layer). For example, the components of the intermediate layer 46 preferably contain 80% by mass or more of polyurethane, and more preferably 90% by mass or more. The porous resin layer for the intermediate layer 46 may contain other additives.

The inner tube 42 is disposed inside the intermediate layer 46, and its outer peripheral surface is made of a material that does not easily adhere to the intermediate layer 46. The inner tube 42 has a cylindrical shape and has at least a two-layer structure, and in the illustrated example, it has a two-layer structure of an outermost layer 48 and an inner layer 50. The outermost layer 48 is provided in close contact with the outside of the inner layer 50. The outermost layer 48 constituting the outer peripheral surface of the inner tube 42 can be, for example, a layer containing a metal material having higher tensile rigidity than the resin constituting the inner tube 42. As an example, the outermost layer 48 is made of metal such as aluminum or copper. To form the outermost layer 48 on the outside of the inner tube 42, for example, a metal sheet may be wrapped around the outer circumference of the inner layer 50, or the inner layer 50 may be inserted inside the metal tube.

The inner layer 50 is formed using, for example, a resin material. Examples of the resin material include polyolefins such as polybutene, polyethylene, crosslinked polyethylene, and polypropylene, and vinyl chloride. Only one type of resin may be used or two or more types may be used in combination. Among the resins, polybutene is preferably used, and preferably contains polybutene as a main component.

Note that the outer circumferential surface of the inner tube 42, that is, the outermost layer 48, may be made of fluororesin. The material constituting the outer circumferential surface of the inner tube 42 may be any material that does not easily adhere to the intermediate layer 46, so that the inner layer 50 is not entirely covered with the outermost layer 48 and a portion of the inner layer 50 is covered with the inner layer 48. It may be exposed on the outer peripheral surface of the tube 42. Further, the outer circumferential surface of the inner tube 42 may be formed in a shape that can suppress adhesion to the intermediate layer 46, for example, a scratch-like thin line (not shown) extending in the axial direction. In other words, any structure may be used as long as it can suppress adhesion between the outer circumferential surface of the inner tube 42 and the intermediate layer 46, compared to a case where the resin material is completely exposed on the outer circumferential surface of the inner tube 42.

Furthermore, the inner layer 50 may be composed of a plurality of layers. Further, at least a portion of the inner layer 50 may be made of metal such as copper. In other words, the inner tube 42 may have three or more layers including the outermost layer 48.

(action, effect)
Next, the functions and effects of this embodiment will be explained. The pipe joint 10 of this embodiment is connected to the composite pipe 14 by inserting a core material 28 into the composite pipe 14, as shown in FIG. 1, for example.

Before inserting the core material 28 into the composite pipe 14, it is preferable to peel off a portion of the corrugated pipe 44 and the intermediate layer 46 at the tip side of the composite pipe 14 to expose the inner pipe 42, as shown in Figures 8 and 9. By gripping the exposed inner pipe 42, it becomes easier to hold the inner pipe 42 and insert the core material 28 of the pipe fitting 10 into the inner pipe 42.

Here, in the composite tube 14 according to the present embodiment, the outer circumferential surface of the inner tube 42 is made of a material that is difficult to adhere to the intermediate layer 46. Specifically, the inner tube 42 has at least a two-layer structure, and the outermost layer 48 forming the outer peripheral surface of the inner tube 42 is made of metal. Further, the intermediate layer 46 is made of a material having a lower melting point than the material of the outer peripheral surface of the inner tube 42 . Therefore, the melting point of the outer peripheral surface is higher than the temperature at which the intermediate layer 46 is formed by melting and foaming the resin outside the inner tube 42 by extrusion molding. Therefore, even if the resin is melted and foamed on the outside of the inner tube 42 by extrusion molding to form the intermediate layer 46, the outer circumferential surface of the inner tube 42 is not melted, so the intermediate layer 46 adheres to the outer circumferential surface of the inner tube 42. It's difficult. Thereby, adhesion between the intermediate layer 46 and the outer circumferential surface of the inner tube 42 during manufacture of the composite tube 14 can be suppressed.

Therefore, when connecting the composite pipe 14 to the pipe joint 10, it becomes easy to contract the corrugated pipe 44 and the intermediate layer 46 in the axial direction of the inner pipe 42 and peel them off from the inner pipe 42.

Further, when manufacturing the composite pipe 14, the step of cooling the foam-molded intermediate layer 46 and then inserting the inner layer into the intermediate layer 46 becomes unnecessary. Therefore, the composite tube 14 in which the corrugated tube 44 and the intermediate layer 46 can be easily peeled off from the inner tube 42 can be manufactured on one production line.

Furthermore, since the inner tube 42 has at least a two-layer structure, the material of the inner layer that does not constitute the outer circumferential surface of the inner tube 42 can be selected with some degree of freedom, while the material between the intermediate layer 46 and the outer circumferential surface of the inner tube 42 can be freely selected. Adhesion can be suppressed.

When the outer surface of the inner pipe 42 is made of fluororesin, the outer surface is slippery, which can prevent adhesion between the intermediate layer 46 and the outer surface of the inner pipe 42. In addition, when connecting the composite pipe 14 to the pipe fitting 10, the corrugated pipe 44 and intermediate layer 46 can be easily peeled off from the inner pipe 42 to expose the inner pipe 42.

Next, the pipe joint 10 of the present embodiment is constructed by inserting the core material 28 into the composite pipe 14 until the end of the composite pipe 14 hits the stopper 34 of the core material 28. You can easily complete the connection work.

When the core material 28 is inserted into the composite pipe 14, the water stop member 18 comes into close contact with the inner periphery of the composite pipe 14 to stop water, and the inner periphery of the annular part 36 of the lock pawl 20 2, and the bite portion 40A of the claw 40 is in contact with the inner peripheral portion of the inner tube 42 in the composite tube 14.

When the composite tube 14 tries to come off from the pipe joint 10, the tip of the biting portion 40A catches the inner periphery of the composite tube 14, thereby suppressing the composite tube 14 from coming off. Note that by causing the tip of the biting portion 40A to bite into the inner surface of the inner tube 42 of the composite tube 14, the effect of suppressing the composite tube 14 from coming off can be further enhanced.

In order to increase the effect of suppressing the composite tube 14 from coming off, it is preferable to make the tip of the biting part 40A bite into the inner periphery of the compound tube 14. It is necessary to enlarge the diameter of the claw 20.

In the pipe fitting 10 of this embodiment, when a large force acts on the composite pipe 14 connected to the pipe fitting 10 in a direction that causes it to move in the direction of removal from the pipe fitting 10, the locking claw 20, whose claw 40 is caught on the inner peripheral surface of the composite pipe 14, also moves together with the composite pipe 14 within the second groove 32 toward the tip side of the core material 28.

When the lock claw 20 moves to the distal end side of the core material 28 together with the composite tube 14 and slides on the inclined surface 32B formed on the bottom surface of the second groove 32, the lock claw 20 moves radially outward by the inclined surface 32B. In other words, when the lock pawl 20 is pressed, a force that expands the diameter of the lock pawl 20 is applied by the inclined surface 32B, and the lock pawl 20 is expanded in diameter.

By expanding the diameter of the lock pawl 20, the pawl 40 bites into the inner peripheral portion of the inner tube 42, and the effect of preventing the composite tube 14 from coming off can be further enhanced.

In the lock pawl 20 of this embodiment, the annular portion 36 is formed of a resin material that is more easily deformed than metal, so if the annular portion 36 is made of metal, in other words, the entire lock pawl is made of metal. Compared to the case where the composite tube 14 is closed, the diameter can be expanded more easily, and the biting portion 40A of the metal claw 40 can bite into the inner periphery of the composite tube 14. Therefore, the lock pawl 20 of this embodiment has an improved effect of preventing the composite tube 14 from coming off, or in other words, an improved holding performance of the composite tube 14.

Further, in the lock pawl 20 of this embodiment, the annular portion 36 has a C-shape, and a plurality of slits 38 extending in the axial direction are formed, so that the lock pawl 20 is continuous in the circumferential direction. Compared to the case, the diameter can be expanded easily, and the biting portion 40A can bite into the inner periphery of the composite pipe 14 more easily.

By the way, when the lock pawl 20 expands in diameter when the compound tube 14 tries to come out, the compound tube 14 is pushed radially outward by the lock pawl 20, and the compound tube 14 is deformed to the expansion side by being pushed by the lock pawl 20. In other words, it is possible that the composite pipe 14 expands in diameter.

In the composite pipe 14 according to this embodiment, when the outermost layer 48 constituting the outer peripheral surface of the inner pipe 42 is made of metal, the expansion of the inner pipe 42 is suppressed when the locking claw 20 catches on the inner peripheral portion of the inner pipe 42. In other words, deformation of the inner pipe 42 toward the expansion side can be suppressed. Therefore, the inner pipe 42 can be more securely held by the locking claw 20.

Therefore, there is no need to provide a cylindrical metal cover (not shown) on the outer periphery of the inner pipe 42 connected to the pipe joint 10 to suppress deformation of the expansion side of the inner pipe 42, and a slimmer composite pipe connection structure 12 can be realized compared to when a cover is provided. In addition, there is no need to attach a cover when connecting the composite pipe 14 to the pipe joint 10, making the connection work easier.

[Other embodiments]
Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it is of course possible to implement various modifications other than the above without departing from the spirit thereof. It is.

The lock pawl 20 of the above embodiment was formed in a C-shape and was not formed continuously in the circumferential direction, but as shown in FIG. 4, it was annular and continuous in the circumferential direction. It may be. The lock pawl 20 shown in FIG. 4 has a slit 38A formed from one end in the axial direction toward the other end, and a slit 38B formed from the other end in the axial direction toward the one end in the circumferential direction. They are alternately formed and continuous in the circumferential direction, but like the lock claws 20, they can be easily expanded and contracted in the radial direction.

DESCRIPTION OF SYMBOLS 10... Pipe joint, 12... Composite pipe connection structure, 14... Composite pipe, 16... Core material, 20... Lock claw, 36... Annular part, 40... Claw, 42... Inner pipe, 44... Corrugated pipe, 44A... Mountain part , 44B...trough, 46...middle layer, 48...outermost layer (outer peripheral surface)

Claims (7)

It is tubular and has an annular peak that is convex toward the outside in the radial direction and an annular valley that is concave on the outside in the radial direction, which are alternately formed in the axial direction to form a bellows-like shape, and the peak and the valley are formed alternately in the axial direction. the axially shortizable corrugated pipe;
an intermediate layer disposed inside the corrugated pipe;
an inner tube disposed inside the intermediate layer, the outer peripheral surface of which is made of a material that is difficult to adhere to the intermediate layer , and has scratch-like streaks extending in the axial direction formed on the outer peripheral surface ;
Composite tube with. The composite pipe according to claim 1, wherein the inner pipe has at least a two-layer structure. The composite tube according to claim 1 or 2, wherein the outer circumferential surface of the inner tube is made of metal. The composite tube according to claim 1 or 2, wherein the outer circumferential surface of the inner tube is made of fluororesin. 5. The composite tube according to claim 1, wherein the intermediate layer is made of a material having a lower melting point than the material of the outer peripheral surface of the inner tube. The composite pipe according to claim 3,
A pipe joint having a cylindrical core material inserted into the inner pipe of the composite pipe, and a lock claw disposed on the outer periphery of the core material;
Composite pipe connection structure with. 2. The lock pawl includes: an annular portion made of a resin material and in contact with the outer circumferential portion; and a metal pawl provided on the annular portion and in contact with the inner circumferential portion of the inner tube. 6. The composite pipe connection structure according to 6.