JP2021063567A - Multiunit tube - Google Patents

Abstract

To provide a multiunit tube that can improve thermal insulation property while keeping down costs.SOLUTION: A multiunit tube 10 includes: an intermediate layer 20 including a tube body 12, a tube outer peripheral wall part 22 disposed along an outer periphery of the tube body 12 and a projection part 24 formed in multiple positions in a circumferential direction of the tube outer peripheral wall part 22, projecting on a radial outside from an outside surface of the tube outer peripheral wall part 22 and extending in an axial direction S of the tube body 12, and capable of extending and contracting in the axial direction S of the tube body 12; and a coating layer 30 constituted of a resin material, covering an outer periphery of the intermediate layer 20 and capable of extending and contracting in the axial direction S of the tube body 12.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composite tube.

Patent Document 1 discloses a composite tube having a main tube, a buffer layer, and a corrugated layer. In such a composite tube, heat retention performance may be required.

JP-A-2017-9072

In the above-mentioned composite pipe, if the intermediate layer is thickened in order to improve the heat retention, the amount of urethane used increases and the cost increases. In addition, it may be difficult to expand and contract the buffer layer and the corrugated layer in the axial direction with respect to the main pipe.

The present invention has been made in consideration of the above facts, and an object of the present invention is to provide a composite tube capable of increasing heat retention while keeping costs low.

The composite pipe according to the first aspect is formed of a tubular pipe body, a pipe outer peripheral wall portion arranged along the outer periphery of the pipe body, and a plurality of positions in the circumferential direction of the pipe outer peripheral wall portion. It is composed of an intermediate layer that has a protruding portion that protrudes radially outward from the outer surface of the portion and extends in the axial direction of the pipe body and that can be expanded and contracted in the axial direction of the pipe body, and a resin material. It covers the outer periphery of the intermediate layer and has a coating layer that can expand and contract in the axial direction of the tubular body.

In this composite pipe, the intermediate layer has a pipe outer peripheral wall portion and a protruding portion. The outer peripheral wall portion of the pipe is arranged along the outer circumference of the pipe body. The protruding portions are formed at a plurality of positions in the circumferential direction of the outer peripheral wall portion of the pipe, and protrude outward in the radial direction from the outer surface of the outer peripheral wall portion of the pipe.

Therefore, the protruding portion can form a space for enhancing heat retention between the outer peripheral wall portion of the pipe and the coating layer, and the amount of material required for forming the intermediate layer can be reduced. Further, since the pipe outer peripheral wall portion is provided along the outer circumference of the pipe body, the intermediate layer can be easily positioned. Furthermore, since the intermediate layer can expand and contract in the axial direction of the tubular body, by applying a force in the axial direction of the tubular body to the intermediate layer and the coating layer, it is compared with the intermediate layer having a thickness over the entire outer periphery of the tubular body. Therefore, it becomes easy to expand and contract in the axial direction of the pipe body, and the end portion of the pipe body can be easily exposed.

In the composite tube according to the second aspect, the intermediate layer is formed of an elastomer or rubber.

The intermediate layer can be easily expanded and contracted in the axial direction by forming it from an elastic elastomer or rubber.

In the composite pipe according to the third aspect, the protruding portion has a protrusion height portion having a height higher than the outer surface of the pipe outer peripheral wall portion and a height higher than the protrusion height portion from the outer surface of the pipe outer peripheral wall portion. The low protrusions are alternately arranged in the axial direction of the pipe body.

In this way, when the height of the protruding portion is changed in the axial direction of the tubular body, the intermediate layer is easily deformed at the protruding portion, and it is possible to easily expand and contract in the axial direction of the tubular body.

In the composite pipe according to the fourth aspect, the protruding portion extends in the axial direction of the pipe body while having an amplitude in the circumferential direction of the outer peripheral wall portion of the pipe.

By giving the protrusion an amplitude in this way, the intermediate layer is easily deformed at the curved protrusion, and it is possible to easily expand and contract in the axial direction of the pipe body.

In the composite pipe according to the fifth aspect, the protruding portion has discontinuous portions at predetermined intervals in the axial direction of the pipe body.

By providing the protruding portion with the discontinuous portion in this way, the intermediate layer is easily deformed at the discontinuous portion, and it is possible to easily expand and contract in the axial direction of the pipe body.

The composite pipe according to the sixth aspect includes an inner layer arranged between the pipe body and the outer peripheral wall portion of the pipe.

By using a material that reduces the frictional force with the pipe body or a material that is advantageous for manufacturing as the inner layer, the degree of freedom in selecting the material of the intermediate layer can be increased.

In the composite tube according to the seventh aspect, the inner layer has heat resistance.

By making the inner layer heat resistant in this way, the inner layer is not thermally deformed by the heat of the intermediate layer during production, and adhesion to the tubular body can be suppressed.

In the composite pipe according to the eighth aspect, the radial outer end of the protruding portion is adhered to the inner surface of the coating layer.

By adhering to the radial outer end of the protruding portion in this way, it is possible to make the intermediate layer follow the coating layer and facilitate the movement in the tubular body axial direction.

In the composite pipe according to the ninth aspect, the outer peripheral wall portion of the pipe is endless in the circumferential direction.

By making the intermediate layer endless in the circumferential direction in this way, it becomes easy to manufacture by extrusion molding, and it becomes easy to expand and contract the intermediate layer in the tube axial direction.

According to the composite pipe according to the present invention, it is possible to improve the heat retention while keeping the cost low.

It is a perspective view which shows the composite pipe which concerns on 1st Embodiment. It is sectional drawing along the radial direction of the composite pipe which concerns on 1st Embodiment. It is a semi-cross-sectional view along the axial direction which shows the composite pipe which concerns on 1st Embodiment. It is sectional drawing along the radial direction which shows the modification (A)-(D) of the intermediate layer of 1st Embodiment. It is sectional drawing along the radial direction which shows other modification (A)-(D) of the intermediate layer of 1st Embodiment. It is a figure which shows the manufacturing apparatus which manufactures the composite tube which concerns on 1st Embodiment. FIG. 1 is a diagram showing a process in which a coating layer and an intermediate layer are shortened and deformed. FIG. 3 is a diagram showing a state in which the coating layer and the intermediate layer are shortened and deformed. It is sectional drawing along the radial direction which shows the modification of the composite pipe of 1st Embodiment. It is sectional drawing along the radial direction of the composite pipe which concerns on 2nd Embodiment. It is a perspective view of the plate intermediate layer of the composite pipe which concerns on 2nd Embodiment. It is a figure which shows the manufacturing apparatus which manufactures the composite tube which concerns on 2nd Embodiment. It is sectional drawing along the axial direction which shows the modification of the plate intermediate layer of 2nd Embodiment. It is sectional drawing along the axial direction which shows the other modification of the plate intermediate layer of 2nd Embodiment. It is a top view which shows the other modification of the plate intermediate layer of 2nd Embodiment.

[First Embodiment]
Hereinafter, the first embodiment will be described with reference to the drawings. The components shown by using the same reference numerals in each drawing mean that they are the same components. In addition, duplicate description and reference numeral in the embodiment described below may be omitted. The present invention is not limited to the following embodiments, and can be carried out with appropriate modifications within the scope of the object of the present invention.

In the present specification, the term "process" is used not only for an independent process but also for a process as long as the purpose is achieved even if the process cannot be clearly distinguished from other processes. include. In the present specification, the amount of each component in the composition is the total amount of the plurality of substances present in the composition unless otherwise specified, when a plurality of substances corresponding to each component are present in the composition. Means. As used herein, the term "principal component" refers to the component having the highest mass-based content in the mixture, unless otherwise specified.

As shown in FIGS. 1 to 3, the composite pipe 10A according to the present embodiment has a pipe body 12, an inner layer 14, an intermediate layer 20, and a coating layer 30.

The tube body 12 is a resin tube made of a resin material. Examples of the resin in the resin material include polyolefins such as polybutene, polyethylene, cross-linked polyethylene, and polypropylene, vinyl chloride, and the like, and the resin may be used alone or in combination of two or more. Among them, polybutene is preferably used, and it is preferable that polybutene is contained as a main component, and for example, it is more preferably contained in an amount of 85% by mass or more in the resin material constituting the tube body 12. Further, the resin material constituting the tube body may contain other additives.

The diameter (outer diameter) of the tubular body 12 is not particularly limited, but can be, for example, a range of 10 mm or more and 100 mm or less, preferably a range of 12 mm or more and 35 mm or less. The thickness of the tubular body 12 is not particularly limited, but for example, 1.0 mm or more and 5.0 mm or less is mentioned, and 1.4 mm or more and 3.2 mm or less is preferable.

The coating layer 30 is made of a resin material, covers the outer periphery of the tubular body 12, the inner layer 14, and the intermediate layer 20, and is expandable and contractible in the axial direction of the tubular body 12. Specifically, in the coating layer 30, annular peaks 32 that are convex outward in the radial direction and annular valleys 34 that are concave outward in the radial direction are alternately formed in the axial direction S of the tubular body 12. Has been done. The mountain portion 32 is arranged outside the valley portion 34 in the radial direction R. In other words, the covering layer 30 is, for example, a corrugated tube. When the coating layer 30 receives the compressive force in the axial direction S of the tubular body 12, the coating layer 30 can be shortened in the axial direction S while being guided by the outer periphery of the tubular body 12.

The thickness of the coating layer 30 is preferably 0.1 mm or more at the thinnest portion and 0.4 mm or less at the thickest portion in order to shorten the coating layer 30.

The diameter of the coating layer 30 (outermost outer diameter) is not particularly limited, but may be, for example, in the range of 13 mm or more and 130 mm or less.

Examples of the resin in the resin material constituting the coating layer 30 include polyolefins such as polybutene, polyethylene, polypropylene, and cross-linked polyethylene, vinyl chloride, and the like. Even if only one type of resin is used, two or more types are used in combination. May be good. Among them, low-density polyethylene is preferably used, and it is preferable that low-density polyethylene is contained as a main component, for example, 80% by mass or more is more preferably contained in the resin material constituting the coating layer, and 90% by mass or more is contained. More preferred.

The inner layer 14 is laminated along the outer peripheral surface of the tubular body 12 so as to cover the outer peripheral surface of the tubular body 12. The inner layer 14 can be formed of, for example, a porous resin layer. Examples of materials for the porous resin layer include polyurethane, polystyrene, polyethylene, polypropylene, and ethylene propylene diene rubber, and mixtures of these resins. The inner layer 14 can also be formed of a film layer. As an example of the material of the film layer, a polyolefin-based resin can be used, and examples of the polyolefin-based resin include polyethylene and polypropylene. The inner layer 14 is movable relative to the tubular body 12 in the axial direction S.

By providing the inner layer 14 with heat resistance, deformation of the intermediate layer 20 to be described later due to heat can be suppressed at the time of manufacture, and adhesion to the tubular body 12 can be suppressed. The thickness T1 of the inner layer 14 is preferably in the range of 10 μm to 3 mm.

The intermediate layer 20 is arranged between the inner layer 14 and the covering layer 30, and has a pipe outer peripheral wall portion 22 and a protruding portion 24. The pipe outer peripheral wall portion 22 is tubular along the outer circumference of the pipe body 12 and is arranged so as to cover the outer peripheral surface of the inner layer 14. The thickness T2 of the outer peripheral wall portion 22 of the pipe is preferably in the range of 10 μm to 1 mm.

The protruding portion 24 is integrally formed with the outer peripheral wall portion 22 of the pipe, and is formed as a protrusion extending radially outward from the outer peripheral surface of the outer peripheral wall portion 22 of the pipe and extending in the axial direction S of the pipe body 12. Has been done. The cross-sectional shape of the projecting portion 24 is, for example, a fan shape having a long radial outside in the circumferential direction as shown in FIG. 4 (A), and a radial direction in the circumferential direction as shown in FIG. 4 (B). The inside can be a long trapezoidal shape, a semicircular shape as shown in FIG. 4 (C), a triangular shape as shown in FIG. 4 (D), and the like.
Further, in FIGS. 4 (A) to 4 (D), the protruding portions 24 are solid, but each protruding portion 24 has a hollow R as shown in FIGS. 5 (A) to 5 (D). It may be a formed shape.

Further, the projecting portions 24 are formed at three locations on the outer surface of the outer peripheral wall portion 22 of the pipe at equal intervals in the circumferential direction (intervals forming 120 ° from each other when viewed from the center of the axis). The protrusion height H1 of the protrusion 24 from the outer peripheral surface of the pipe outer peripheral wall portion 22 is preferably in the range of 3 mm to 60 mm. Further, the width L1 of the protruding portion 24 in the circumferential direction of the pipe outer peripheral wall portion 22 is preferably in the range of 10 μm to 1 mm.

A space R1 is formed between the portion of the outer peripheral wall portion 22 of the pipe where the protruding portion 24 is not formed and the covering layer 30. The space R1 is formed at three positions between the projecting portions 24 adjacent to each other when viewed from the axial direction S.

The intermediate layer 20 can be made of, for example, a material containing an elastomer resin, rubber, or the like as a main component. In the intermediate layer 20, both the protruding portion 24 and the pipe outer peripheral wall portion 22 are elastic members that can be elastically deformed, and the intermediate layer 20 can be expanded and contracted in the axial direction S of the pipe body 12. The thickness T2 of the outer peripheral wall portion 22 of the pipe and the width L1 of the protruding portion 24 are set so that the intermediate layer 20 can expand and contract in the axial direction S of the pipe body 12.

The protruding portion 24 is adhered to the inner peripheral surface of the coating layer 30. Specifically, the radial outer end surface 24A of the protruding portion 24 is adhered to the inner wall surface 34A of the valley portion 34 of the covering layer 30.

The intermediate layer 20 and the coating layer 30 can be manufactured by extrusion molding using a manufacturing method described later. When the intermediate layer 20 and the coating layer 30 are molded at the same time by extrusion molding, for example, when the intermediate layer 20 has a porous structure, the resin of the coating layer 30 easily enters the protruding portion 24. Further, when the intermediate layer 20 is formed of rubber or an elastomer, it is easily fused with the coating layer 30. As a result, the intermediate layer 20 can be adhered to the inner peripheral surface of the coating layer 30. The intermediate layer 20 and the coating layer 30 may be adhered to each other using an adhesive.

Further, the inner peripheral surface of the pipe outer peripheral wall portion 22 is adhered to the inner layer 14. Adhesion between the inner peripheral surface of the pipe outer peripheral wall portion 22 and the inner layer 14 can also be performed by heat welding in the manufacturing process or by using an adhesive. For example, when the inner layer 14 has a porous structure, the resin of the outer peripheral wall portion 22 of the pipe easily enters the inner layer 14.

The pipe outer peripheral wall portion 22 of the intermediate layer 20 is endless in the circumferential direction. The intermediate layer 20 can be molded endlessly in the circumferential direction by extrusion molding described later.

(Manufacturing method of composite pipe 10A)
Next, a method for manufacturing the composite pipe 10A will be described.

For the production of the composite pipe 10A, for example, the production apparatus 50 shown in FIG. 6 can be used. The manufacturing apparatus 50 includes a jig 51, an inner extruder 52, an inner die 53, an outer extruder 54, an outer die 55, a corrugating die 56, a cooling tank 58, and a take-up device 59. In the manufacturing process of the composite pipe 10A, the right side of FIG. 6 is the upstream side, and the pipe body 12 is manufactured while moving from the right side to the left side. Hereinafter, this moving direction is referred to as a manufacturing direction Y. The jig 51, the inner die 52, the outer die 55, the corrugated die 56, the cooling tank 58, and the take-up device 59 are arranged in this order with respect to the manufacturing direction Y, and the inner extruder 52 is the inner die 53. Located above, the outer extruder 54 is located above the outer die 55.

Although not shown, a roll in which the tubular body 12 wound in a coil shape and the sheet-shaped member 14S constituting the inner layer 14 are wound in a roll shape is arranged upstream of the jig 51. There is. By being pulled in the manufacturing direction Y by the take-up device 39, the coil-shaped tubular body 12 and the roll-shaped sheet-shaped member 14S are continuously pulled out. In front of the inner die 53, the sheet-like member 14S is wound around the outer peripheral surface of the continuously drawn tube body 12 by the jig 51 over the entire circumference.

A resin material (melt of the resin composition of the intermediate layer 20) melted from the inner die 52 is extruded from the inner die 52 into the outer circumference of the sheet-like member 14S wound around the outer circumference of the tubular body 12 in the cross-sectional shape of the intermediate layer 20. The intermediate layer 20 is formed. A resin material (a melt of a resin composition for forming a coating layer 30) melted from an outer die 55 is extruded in a cylindrical shape on the outer periphery of the intermediate layer 20 to form a resin layer 30A. At this time, the MFR (Melt Flow Rate) of the resin used is preferably 0.25 or more, more preferably 0.3 or more, and further preferably 0.35 or more and 1.2 or less. .. By setting the MFR to 0.25 or more, when the intermediate layer 20 is a porous resin layer, the resin of the coating layer 30 easily enters the porous structure, and the outer end surface and the coating layer of the protruding portion 24 of the intermediate layer 20 The degree of adhesion with 30 can be increased.

After the tubular extruded body 21 composed of the tubular body 12, the sheet-shaped member 14S, the intermediate layer 20, and the resin layer 30A is formed, the corrugating process is performed by the corrugating die 56 arranged on the downstream side of the outer die 55. Will be done. On the inner circumference of the corrugation mold 56, an annular cavity 56A is formed in a portion of the coating layer 30 corresponding to the peak portion 32, and an annular inner protrusion 56B is formed in a portion corresponding to the valley portion 34. Each cavity 56A is formed with a vent hole 56C having one end communicating with the cavity 56A and penetrating the corrugating die 56. In the cavity 56A, air is taken from the outside of the corrugation mold 56 through the ventilation hole 56C.

On the downstream side of the outer die 55, the corrugated die 56 covers the outer periphery of the tubular extruder 21 while pressing the resin layer 30A by the inner protrusion 56B, and moves in the manufacturing direction Y together with the tubular body 12. At this time, intake is performed from the outside of the corrugation die 56 to create a negative pressure inside the cavity 56A. As a result, the resin layer 30A moves outward in the radial direction, and a bellows-shaped coating layer 30 is formed along the corrugated mold 56. After the corrugation step is performed in the corrugation mold 56, the coating layer 30 is cooled in the cooling tank 58. In this way, the composite tube 10A is manufactured.

(Action)
The composite tube 10A of the present embodiment is configured as described above, and its operation will be described below.

In the composite pipe 10A of the present embodiment, since the intermediate layer 20 has the pipe outer peripheral wall portion 22 and the protruding portion 24, the protruding portion 24 forms a space R1 between the pipe outer peripheral wall portion 22 and the covering layer 30. be able to. Due to this space R1, the heat retention property is enhanced, and the amount of the material required for forming the intermediate layer 20 for ensuring the heat retention property can be reduced.

Further, since the pipe outer peripheral wall portion 22 is provided along the outer circumference of the pipe body 12, the intermediate layer 20 can be easily positioned with respect to the pipe body 12.

Further, since the intermediate layer 20 can be expanded and contracted in the axial direction of the tubular body 12, by applying a force in the axial direction S to the intermediate layer 20 and the covering layer 30, an intermediate structure having a thickness on the entire outer periphery of the tubular body 12 is provided. Compared with the case of the layer, it is easy to expand and contract in the axial direction S, and as shown in FIGS. 7 and 8, the end portion of the tubular body 12 can be easily exposed. Further, since the intermediate layer 20 is formed of an elastic member, the intermediate layer 20 can be easily expanded and contracted in the axial direction S.

Further, in the composite pipe 10A of the present embodiment, since the pipe outer peripheral wall portion 22 of the intermediate layer 20 has an endless shape in the circumferential direction, the production by the above-mentioned extrusion molding becomes easy and the joint does not twist. , The intermediate layer 20 can easily expand and contract in the axial direction S.

Further, since the outer end surface 24A of the protrusion 24 is adhered to the inner side wall 34A of the valley portion 34 of the coating layer 30, the intermediate layer 20 is made to follow the coating layer 30, and both the coating layer 30 and the intermediate layer 20 are formed. Can be easily expanded and contracted in the axial direction S.

Further, since the composite tube 10A of the present embodiment includes the inner layer 14, by making the inner layer 14 heat resistant, deformation of the intermediate layer 20 to be described later due to heat is suppressed at the time of manufacture, and the tube body 12 And the intermediate layer 20 can be suppressed from being adhered to each other. Further, by using a material that reduces the frictional force with the pipe body 12 or a material that is advantageous for manufacturing as the inner layer 14, the degree of freedom in selecting the material of the intermediate layer 20 can be increased. The inner layer 14 is not always necessary, and as shown in FIG. 9, the inner layer 14 may not have the inner layer 14.

Further, in the present embodiment, the protruding portions 24 of the intermediate layer 20 are provided at three locations at equal intervals in the circumferential direction, but may be provided at one location, two locations, four locations, five locations, six locations, or seven or more locations. .. Further, the intervals of the protrusions 24 do not necessarily have to be equal, but by providing them at equal intervals, the coating layer 30 can be held from the inner peripheral side in a well-balanced manner.

[Second Embodiment]
Next, the second embodiment will be described. In the present embodiment, the same parts as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

The composite pipe 10B of the second embodiment includes a plate intermediate layer 40 instead of the intermediate layer 20 of the first embodiment. Moreover, the inner layer 14 is not provided. As shown in FIG. 10, the plate intermediate layer 40 has a shape in which a long protruding portion 44 is formed on a plate-shaped pipe outer peripheral wall portion 42 in a state before being incorporated into the composite pipe 10B. .. In the state of being incorporated in the composite pipe 10B, as shown by the alternate long and short dash line in FIG. 11, the outer peripheral wall portion 42 of the pipe is tubular, and the protruding portion 44 is convex outward in the radial direction. The plate intermediate layer 40 has the same configuration as the intermediate layer 20 of the first embodiment except that a seam 42S is formed on the outer peripheral wall portion 42 of the pipe in a state of being incorporated in the composite pipe 10B.

(Manufacturing method of composite pipe 10B)
Next, a method for manufacturing the composite pipe 10A will be described.

For the production of the composite pipe 10A, for example, as shown in FIG. 12, a manufacturing apparatus 60 having a configuration in which the inner extruder 52 and the inner die 52 are excluded from the manufacturing apparatus 50 of the first embodiment can be used.

In the present embodiment, instead of the sheet-shaped member 14S, a roll in which the sheet-shaped member 40S constituting the plate intermediate layer 40 is wound in a roll shape is arranged, and the sheet-shaped member 40S is made of the pipe body 12 by the jig 61. It is wrapped around the entire outer surface.

A resin material (a melt of the resin composition for forming the coating layer 30) melted from the outer die 55 is extruded into a cylindrical shape on the outer circumference of the sheet-like member 40S wound around the outer circumference of the tubular body 12, and thereafter. The step is carried out in the same manner as in the first embodiment, and the composite pipe 10B is manufactured.

In the present embodiment, since the plate intermediate layer 40 is not extruded, the degree of freedom in selecting the material of the plate intermediate layer 40 and the degree of freedom in the shape of the protruding portion 44 are increased. For example, as an example of the protruding portion 44, as shown in FIG. 13A, a corrugated shape having peaks 45 and valleys 46 alternately in the axial direction S can be formed. Further, as shown in FIG. 13B, the protruding portion 47 may be arranged discontinuously in the axial direction S. Further, as shown in FIG. 14, the protruding portion 48 having an amplitude in the circumferential direction may be used. By providing the inflection point in the axial direction S or the discontinuous portion 47S in this way, the protruding portion is easily deformed at the inflection point or the discontinuous portion, and expansion and contraction in the axial direction S is easy. Can be.

Further, the plate intermediate layer 40 can be formed of rubber, or the pipe outer peripheral wall portion 42 and the protruding portion 44 can be easily formed of different materials.

The intermediate layer having the protrusions having the shapes shown in FIGS. 13A, 13B, and 14 may be formed by extrusion molding. In that case, the outer peripheral wall portion 42 of the pipe can be made endless in the circumferential direction.

[Other Embodiments]
Although an example of the embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above, and other than the above, various modifications can be made within a range not deviating from the gist thereof. Of course there is.

Although a corrugated tube is mentioned as an example of the coating layer 30, the coating layer 30 is made of a flexible material such as an elastomer that does not have irregularities like the corrugated tube and is deformable when the end portion of the tube body 12 is exposed. May be configured.

10A, 10B composite pipe 12 pipe body, 14 inner layer, 20 intermediate layer 22 pipe outer wall, 24 protrusion, 30 covering layer 40 plate intermediate layer (intermediate layer), 42 pipe outer wall 44, 47, 48 protrusion , 45 Mountains (protruding height), 46 Valleys (protruding low)

Claims (9)

Tubular tube and
The outer peripheral wall of the pipe is arranged along the outer periphery of the pipe, and the outer peripheral wall of the pipe is formed at a plurality of positions in the circumferential direction and protrudes radially outward from the outer surface of the outer wall of the pipe and the shaft of the pipe. An intermediate layer having a protruding portion extending in the direction and expanding and contracting in the axial direction of the pipe body,
A coating layer made of a resin material, which covers the outer periphery of the intermediate layer and can be expanded and contracted in the axial direction of the tubular body,
Composite pipe with. The composite tube according to claim 1, wherein the intermediate layer is made of an elastomer or rubber. The protruding portion includes a protruding portion having a high height from the outer surface of the outer peripheral wall portion of the pipe and a protruding portion having a lower height from the outer surface of the outer peripheral wall portion of the pipe than the protruding portion. The composite tube according to claim 1 or 2, wherein the composite tubes are arranged alternately in the axial direction of the body. The composite pipe according to any one of claims 1 to 3, wherein the protruding portion extends in the axial direction of the pipe body while having an amplitude in the circumferential direction of the outer peripheral wall portion of the pipe. The composite pipe according to any one of claims 1 to 4, wherein the protruding portion has discontinuous portions at predetermined intervals in the axial direction of the pipe body. The composite pipe according to any one of claims 1 to 5, further comprising an inner layer arranged between the pipe body and the outer peripheral wall portion of the pipe. The composite tube according to claim 6, wherein the inner layer has heat resistance. The composite tube according to any one of claims 1 to 7, wherein the radial outer end of the protruding portion is adhered to the inner surface of the coating layer. The composite pipe according to any one of claims 1 to 8, wherein the outer peripheral wall portion of the pipe is endless in the circumferential direction.

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