JP2020190273A - Composite pipe - Google Patents

Abstract

To provide a composite pipe holding a pipe body inside a coating layer, which holds the pipe body inside the coating layer and can facilitate expansion/contraction of the coating layer with respect to the pipe body.SOLUTION: A composite pipe 10 has an inner pipe 12, a corrugated pipe 20, and a holding part 30. The corrugated pipe 20 covers an outer peripheral surface 13 of the inner pipe 12 and is expandable and contractable in an axial direction of the inner pipe 12. The holding part 30 has a corrugated member 32 arranged between the inner pipe 12 and the corrugated pipe 20 and elastically deformed in a Z direction as the corrugated pipe 20 expands and contracts, and holds the inner pipe 12 inside the corrugated pipe 20.SELECTED DRAWING: Figure 1

Description

The present invention relates to a composite tube.

Patent Document 1 includes a tubular body, a flexible protective layer that covers the outer peripheral surface of the tubular body and has valleys formed on the inner peripheral surface, and a holding layer that covers the outer peripheral surface of the protective layer. The tube is disclosed.

Japanese Unexamined Patent Publication No. 2013-231490

By the way, in a composite tube that holds a tubular body inside a coating layer, in a configuration in which another member is in close contact with the coating layer as in the configuration of Patent Document 1, the coating layer expands and contracts along the axial direction of the tubular body. If so, other members may hinder the expansion and contraction of the coating layer, and there is room for improvement.

An object of the present invention is to provide a composite tube that holds a tube inside the coating layer, which can hold the tube inside the coating layer and easily expand and contract the coating layer with respect to the tube. The purpose is to get.

The composite tube according to the first aspect includes a tube body, a coating layer formed in a tubular shape, covering the outer peripheral surface of the tube body, and expanding and contracting in the axial direction of the tube body, and the tube body and the coating layer. It has a linear member arranged between the two, which is elastically deformed in the axial direction with the expansion and contraction of the coating layer, and has a holding portion for holding the tube body inside the coating layer.

According to the composite pipe according to the first aspect, the pipe body can be held inside the coating layer by the holding portion holding the pipe body. Further, when the coating layer is expanded and contracted along the axial direction of the tubular body, the holding portion is elastically deformed in the axial direction as the coating layer expands and contracts. Here, since the holding portion has the linear member and the expansion / contraction direction of the coating layer and the elastic deformation direction of the linear member are aligned, the expansion / contraction of the coating layer is less likely to be hindered by the holding portion. That is, in the composite pipe that holds the pipe body inside the coating layer, the pipe body can be held inside the coating layer and the coating layer can be easily moved with respect to the pipe body.

The frictional resistance between the holding portion and the outer peripheral surface of the composite pipe according to the second aspect is smaller than the frictional resistance between the holding portion and the coating layer.

According to the composite pipe according to the second aspect, when the holding portion is elastically deformed in the axial direction, the frictional resistance acting on the contact portion between the holding portion and the coating layer is applied to the contact portion between the holding portion and the pipe body. Greater than the acting frictional resistance. Here, since the frictional resistance acting on the contact portion between the holding portion and the coating layer is large, the holding portion is easily elastically deformed as the coating layer expands and contracts, so that the coating layer and the holding portion are integrally deformed. It will be easier. Further, since the frictional resistance acting on the contact portion between the holding portion and the pipe body is small, the holding portion is difficult to stay on the outer peripheral surface of the pipe body, so that the coating layer and the holding portion are moved relative to the pipe body. It becomes easy to make it. Due to these actions, the coating layer can be further easily moved with respect to the tubular body.

The first contact area between the holding portion and the outer peripheral surface of the composite pipe according to the third aspect is smaller than the second contact area between the holding portion and the covering layer.

According to the composite pipe according to the third aspect, since the first contact area is smaller than the second contact area, the frictional resistance between the holding portion and the outer peripheral surface is smaller than the frictional resistance between the holding portion and the coating layer. There is a possibility of becoming. As a result, the frictional resistance acting on the contact portion between the holding portion and the tubular body may be reduced, and the holding portion may not easily stay on the outer peripheral surface of the tubular body. Therefore, the covering layer and the holding portion are attached to the tubular body. It can be made relatively easy to move.

The linear member of the composite pipe according to the fourth aspect is a plurality of corrugated members arranged in a circumferential direction of the pipe body at intervals and formed into a corrugated shape having an amplitude in an intersecting direction intersecting the axial direction. Is.

According to the composite pipe according to the fourth aspect, since the shape of the corrugated member is such that it can be easily expanded and contracted in the axial direction of the pipe body, the coating layer and the holding portion can be easily deformed integrally. Further, since a plurality of corrugated members are arranged at intervals in the circumferential direction of the tubular body, the number of places where the corrugated members hold the tubular body is larger than that of one configuration, so that the tubular body The holding state can be stabilized. That is, it is possible to suppress the expansion and contraction of the coating layer from being hindered and to stabilize the holding state of the tubular body.

The linear member of the composite pipe according to the fifth aspect is a spiral member spirally wound around the outer peripheral surface of the pipe body.

According to the composite pipe according to the fifth aspect, since the shape of the spiral member is a shape that can be easily expanded and contracted in the axial direction of the pipe body, the coating layer and the holding portion can be easily deformed integrally. Further, since the pipe body can be held by one spiral member, the number of parts of the holding portion can be reduced. That is, it is possible to suppress the expansion and contraction of the coating layer from being hindered and to reduce the number of members constituting the composite tube.

The linear member of the composite pipe according to the sixth aspect is a mesh member formed in a network formed by joining a plurality of corrugated vertices having amplitudes in an intersecting direction intersecting the axial direction and covering the outer peripheral surface in the circumferential direction. is there.

According to the composite pipe according to the sixth aspect, since the shape of the net-like member is a shape that can be easily expanded and contracted in the axial direction of the pipe body, the coating layer and the holding portion can be easily deformed integrally. Further, since the mesh member covers the outer peripheral surface of the tubular body in the circumferential direction, the contact portion between the outer peripheral surface of the tubular body and the mesh member when the coating layer is rotated (twisted) around the central axis. However, the bias toward a part of the circumferential direction of the tube is suppressed. That is, it is possible to suppress the expansion and contraction of the coating layer from being hindered and to suppress the bias of the holding portion when the coating layer is twisted.

The coating layer of the composite pipe according to the seventh aspect is a corrugated pipe that repeats peaks and valleys in the axial direction.

According to the composite pipe according to the seventh aspect, the coating layer is configured to repeat peaks and valleys in the axial direction, so that the coating layer is covered with less force than a configuration in which the coating layer extends linearly. Since the layer can be deformed in the axial direction, the coating layer can be easily expanded and contracted in the axial direction.

According to the present invention, in a composite tube that holds a tube inside the coating layer, a composite tube that can hold the tube inside the coating layer and easily expand and contract the coating layer with respect to the tube is provided. Obtainable.

It is a perspective view which shows the composite pipe which concerns on 1st Embodiment. It is a vertical cross-sectional view of a part of the corrugated tube shown in FIG. It is a vertical cross-sectional view of the cross section orthogonal to the central axis in the corrugated member shown in FIG. It is explanatory drawing when the contact portion between a corrugated pipe and a corrugated member and the contact portion between a corrugated member and an inner pipe, shown in FIG. 1, are viewed from the radial outside of the inner pipe. It is a perspective view which shows the completed state of the composite pipe shown in FIG. It is a perspective view which shows the state in which the corrugated pipe in the composite pipe shown in FIG. 4 is contracted in the axial direction. It is a perspective view which shows the composite pipe which concerns on 2nd Embodiment. It is a perspective view which shows the state in which the corrugated pipe in the composite pipe shown in FIG. 8 is contracted in the axial direction. It is explanatory drawing which shows the composite pipe which concerns on 3rd Embodiment. It is a perspective view which shows the state which the corrugated pipe in the composite pipe shown in FIG. 9 was contracted in the axial direction. It is a perspective view which shows the composite pipe which concerns on 1st modification. It is a vertical sectional view of the cross section orthogonal to the central axis in the corrugated member which concerns on the 2nd modification.

[First Embodiment]
As an example of the present disclosure, the composite pipe 10 according to the first embodiment will be described. The components shown by the same reference numerals in each drawing mean that they are the same components. In each embodiment described below, duplicate description and reference numerals may be omitted.

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.

The composite tube 10 shown in FIG. 1 has an inner tube 12 as an example of a tubular body, a corrugated tube 20 as an example of a tubular covering layer, and a holding that holds the inner tube 12 inside the corrugated tube 20. It has a part 30 and. The composite pipe 10 is configured as a long member long in the axial direction, and is cut in a direction orthogonal to the axial direction according to a required length. The connection between the one composite pipe 10 and the other composite pipe 10 shows the one inner pipe 12 and the other inner pipe 12 in a state where the corrugated pipe 20 is contracted (the inner pipe 12 is exposed). It is done by connecting with a tubular joint member that is not.

<Inner tube>
The inner tube 12 is made of a resin material and is formed in a cylindrical shape. Further, the inner pipe 12 is configured as a long member long in the axial direction. In the following description, the axial direction of the inner tube 12 will be referred to as the Z direction. Further, the radial direction of the inner pipe 12 is referred to as the D direction. The Z direction is also the axial direction of the composite pipe 10. The central axis K of the inner pipe 12 is also the central axis of the composite pipe 10. The inner pipe 12 has an outer peripheral surface 13.

Examples of the resin material constituting the inner tube 12 include polyolefins such as polybutene, polyethylene, cross-linked polyethylene, and polypropylene, vinyl chloride, and the like. The type of resin used for the inner tube 12 may be one type or two or more types. Polybutene is preferably used for the inner tube 12, and it is preferable that the inner tube 12 contains polybutene as a main component. For example, it is more preferable that the resin material constituting the inner tube 12 contains 85% by mass or more of polybutene. The resin material constituting the inner tube 12 may contain an additive. The inner tube 12 is not expanded or contracted in the Z direction.

The outer diameter of the inner tube 12 is not particularly limited, but can be, for example, in the range of 10 mm or more and 100 mm or less, preferably in the range of 12 mm or more and 35 mm or less. The thickness of the inner tube 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.

<Corrugated pipe>
The corrugated pipe 20 shown in FIG. 2 has an inner diameter larger than the outer diameter of the inner pipe 12, and covers the outer peripheral surface 13 of the inner pipe 12 when viewed from the outside in the D direction. In other words, the corrugated pipe 20 is configured as an outer pipe of the composite pipe 10. Further, the corrugated pipe 20 and the inner pipe 12 are arranged (coaxially) with the central axes K aligned with each other. Further, the corrugated pipe 20 and the inner pipe 12 are arranged at intervals in the D direction. The length of the corrugated pipe 20 in the Z direction is set to be substantially the same as the length of the inner pipe 12 in the Z direction. Note that in FIG. 2, the holding unit 30 (see FIG. 1) is not shown.

Further, the corrugated pipe 20 is made of a resin material. Examples of the resin material constituting the corrugated pipe 20 include polyolefins such as polybutene, polyethylene, polypropylene, and cross-linked polyethylene, vinyl chloride, and the like. The type of resin used for the corrugated pipe 20 may be one type or two or more types. Low-density polyethylene is preferably used for the corrugated tube 20, and it is preferable that the corrugated tube 20 contains low-density polyethylene as a main component. For example, in the resin material constituting the corrugated pipe 20, it is more preferable to contain 80% by mass or more, and further preferably 90% by mass or more.

The MFR (Melt Flow Rate <JIS K 7210-1: 2014>) of the resin used for the corrugated pipe 20 is preferably 0.25 or more, more preferably 0.3 or more, and 0.4 or more. It is more preferably 1.2 or less. By setting the MFR to 1.2 or less, burrs are less likely to occur. When the MFR is larger than 1.2, the molten resin easily flows into the parting surface of the mold for forming the corrugated pipe 20, and burrs are likely to occur. The resin material constituting the corrugated pipe 20 may contain other additives.

Further, the corrugated pipe 20 is formed in a bellows shape in which an annular peak portion 22 and an annular valley portion 24 are repeated in the Z direction, and can be expanded and contracted (extended and shortened) in the Z direction. Specifically, in the corrugated pipe 20, when viewed from a direction orthogonal to the Z direction, a mountain portion 22 that bulges outward in the D direction and a valley portion 24 that dents inward in the D direction alternate in the Z direction. It has a continuously formed structure. The outermost portion of the corrugated pipe 20 in the D direction is the outer wall 22A, the innermost portion in the D direction is the inner side wall 24A, and the intermediate portion between the outer wall 22A and the inner side wall 24A in the D direction is the boundary M. Here, with respect to the boundary M, the outer portion in the D direction is the mountain portion 22, and the inner portion in the D direction is the valley portion 24. The inner surface of the inner side wall 24A in the D direction is referred to as an inner surface 25. The inner surface 25 is an example of the inner peripheral surface of the corrugated pipe 20.

The mountain portion 22 and the valley portion 24 are formed in a substantially rectangular wavy shape as an example when viewed from a direction orthogonal to the D direction and the Z direction. In other words, the outer wall 22A and the inner side wall 24A are each formed in a flat plate shape along the Z direction. Although not particularly limited, it is preferable that the length of one mountain portion 22 in the Z direction is set longer than the length of one valley portion 24 in the Z direction. Further, the length of one mountain portion 22 in the Z direction is 1.2 times the length of one valley portion 24 in the Z direction in order to ensure the ease of deformation of the outer wall 22A at the time of shortening deformation. The above is preferable.

Further, the length of one valley portion 24 in the Z direction is preferably 0.8 mm or more. This is because if the length of one valley portion 24 in the Z direction is less than 0.8 mm, the width of the valley portion of the mold for manufacturing the corrugated pipe 20 is too small, so that the portion corresponding to the valley portion of the mold is This is because it becomes fragile and it becomes difficult to mold the corrugated tube 20. On the other hand, the length of one mountain portion 22 in the Z direction is preferably 5 times or less the length of one valley portion 24 in the Z direction. This is because the flexibility of the composite tube 10 can be maintained. Further, if the length of one mountain portion 22 in the Z direction is too long, the contact area with the ground becomes large when the composite pipe 10 is laid, which makes it difficult to construct.

The thickness of the corrugated pipe 20 in the D direction is preferably 0.1 mm or more at the thinnest portion and 0.4 mm or less at the thickest portion so that the corrugated pipe 20 can be expanded and contracted in the Z direction. The thickness of the outer side wall 22A is, for example, thinner than the thickness of the inner side wall 24A. The thickness of the outer side wall 22A is preferably 0.9 times or less the thickness of the inner side wall 24A in order to ensure the ease of deformation of the outer wall surface 22A during shortening deformation.

The length corresponding to the difference between the outer wall 22A and the inner side wall 24A in the D direction (hereinafter referred to as a radius difference) is preferably 800% or less of the average thickness of the corrugated pipe 20. If the radius difference is large, even if the portion of the mountain portion 22 along the Z direction is not deformed, the valley portion 24 does not bulge outward in the D direction at the time of shortening, and the adjacent mountain portions 22 do not approach each other. It is hard to be in a distorted state. When the radius difference is 800% or less of the average thickness of the corrugated pipe 20, the length of the mountain portion 22 in the Z direction is changed to the length of the valley portion 24 in the Z direction in order to suppress the above-mentioned deformation state. It is effective to make it longer than the length of. It is more effective when the radius difference is 600% or less of the average thickness of the corrugated pipe 20.

The diameter of the corrugated pipe 20 (outermost outer diameter) is not particularly limited, but can be set in the range of, for example, 13 mm or more and 130 mm or less.

<Holding part>
The holding portion 30 shown in FIG. 1 is configured as a separate body from the inner pipe 12 and the corrugated pipe 20. Further, the holding portion 30 has four corrugated members 32 as an example. The four corrugated members 32 are arranged at intervals in the circumferential direction of the inner pipe 12. The configurations of the four corrugated members 32 are the same.

The corrugated member 32 is an example of a linear member, and is arranged between the inner pipe 12 and the corrugated pipe 20 in the D direction of the inner pipe 12. In addition, "linear" means including at least one of a straight line and a curved line. That is, the "linear member" means a member having a shape including at least one of a straight line portion and a curved line portion.

In the present disclosure, "a state in which the corrugated member 32 is in linear contact with the inner pipe 12 and the corrugated pipe 20" means that the corrugated member 32 is a part of the outer peripheral surface 13 of the inner pipe 12 and the inner surface 25 of the corrugated pipe 20. It means the state of contact with only a part of. On the contrary, "a state in which the corrugated member 32 is in surface contact with the inner pipe 12 and the corrugated pipe 20" means that the corrugated member 32 is in contact with the entire outer peripheral surface 13 of the inner pipe 12 and the entire inner surface 25 of the corrugated pipe 20. Means the state of doing. The corrugated member 32 is sandwiched between the inner pipe 12 and the corrugated pipe 20 in the D direction of the inner pipe 12. As a result, the corrugated member 32 holds the inner pipe 12 inside the corrugated pipe 20.

Further, the corrugated member 32 is made of an elastomer. Examples of the elastomer include ethylene propylene diene rubber and silicone rubber. Among them, it is preferable to use silicone rubber.

Further, the corrugated member 32 is formed in a sinusoidal shape with the Z direction as the traveling direction as an example when viewed from the D direction of the inner tube 12. In other words, the corrugated member 32 is formed in a waveform having an amplitude in the direction orthogonal to the Z direction when viewed from the D direction of the inner tube 12. The orthogonal direction is an example of the crossing direction. As described above, the corrugated member 32 is formed so as to be elastically deformable in the Z direction. The corrugated member 32 is configured to be elastically deformed in the Z direction as the corrugated tube 20 expands and contracts in the Z direction.

As shown in FIG. 3, the corrugated member 32 is formed in a tubular shape as an example. In other words, the corrugated member 32 is formed as a rubber tube. Further, the shape of the corrugated member 32 is a shape in which the rectangular portion 33 and the semicircular portion 34 are integrated when viewed from the central axis direction of the corrugated member 32. The cross section orthogonal to the central axis of the corrugated member 32 is referred to as a cross section S1. In the cross section S1, the rectangular portion 33 and the semicircular portion 34 are arranged side by side in the D direction. Further, the outer end surface 33A of the rectangular portion 33 in the D direction is a plane orthogonal to the D direction and is in contact with a part of the inner surface 25. The inner end surface 34A (curved surface located at the apex portion of the semicircle) of the semicircle portion 34 in the D direction is in contact with a part of the outer peripheral surface 13. In FIG. 3, hatching is omitted in order to show the cross-sectional shape of the corrugated member 32 in an easy-to-understand manner.

The frictional resistance between the holding portion 30 and the outer peripheral surface 13 is smaller than the frictional resistance between the holding portion 30 and the inner surface 25 of the corrugated pipe 20. In the present disclosure, "the frictional resistance between the holding portion 30 and the outer peripheral surface 13 is small" means that the holding portion 30 is relatively slippery in the Z direction with respect to the outer peripheral surface 13. Further, "the frictional resistance between the holding portion 30 and the inner surface 25 is large" means that the holding portion 30 is easily expanded and contracted together with the corrugated pipe 20 as the corrugated pipe 20 moves in the Z direction.

FIG. 4 is a schematic view showing a state in which a part of the outer peripheral surface 13, a part of the corrugated member 32, and a part of the corrugated pipe 20 are viewed from the outside in the D direction. As a part of the corrugated pipe 20, the inner side wall 24A is shown by an imaginary line (dashed line). As a part of the corrugated member 32, a portion extending in an oblique direction intersecting the Z direction is shown by a solid line. Further, regarding the corrugated member 32, the outer end face 33A is shown by a solid line, and the inner end face 34A is shown by a broken line.

When viewed from the outside in the D direction, the intersections of the outer line of the inner side wall 24A and the outer line of the outer end surface 33A are designated as points A, B, C, and D. The points A and B are arranged at intervals in a direction (referred to as a Y direction) orthogonal to the Z direction. The points C and D are arranged at intervals in the Y direction. The quadrangle ABCD connecting the points A, B, C, and D is a parallelogram. The area of this parallelogram is referred to as the second contact area SB.

On the other hand, the intersections of the outer line of the inner side wall 24A and the outer line of the inner end surface 34A are designated as points E, F, G, and H. The points E and F are arranged on a straight line connecting the points A and B and between the points A and B at intervals in the Y direction. The points G and H are arranged on a straight line connecting the points C and D and between the points C and D at intervals in the Y direction. The quadrangle EFGH connecting the points E, F, G, and H is a parallelogram. The area of this parallelogram is referred to as the first contact area SA.

Since the quadrangle EFGH is included in the quadrangle ABCD, the first contact area SA is smaller than the second contact area SB. That is, the first contact area SA between the holding portion 30 and the outer peripheral surface 13 is smaller than the second contact area SB between the holding portion 30 and the corrugated pipe 20.

<Manufacturing of composite pipe>
As a method for manufacturing the composite tube 10 shown in FIG. 5, for example, the following method can be considered. Specifically, four corrugated members 32 are supplied to the outer peripheral surface 13 of the inner pipe 12 sent in the Z direction so as to be spaced in the circumferential direction and linear in the Z direction. Immediately after the supply of the four corrugated members 32, the resin material (melt of the resin composition for forming the corrugated tube 20) melted from a die (not shown) is extruded into a cylindrical shape, whereby the inner tube 12 and the four corrugations are formed. The member 32 is covered with the resin material.

After the inner pipe 12, the four corrugated members 32, and the cylindrical resin material are put together, a step of forming the resin material in a bellows shape is performed using a corrugated mold arranged on the downstream side of the die. The corrugated tube 20 is formed by forming the resin material into a bellows shape. After the corrugation process is performed in the corrugated mold, each member is cooled in a cooling tank (not shown). In this way, the composite pipe 10 having the inner pipe 12, the holding portion 30, and the corrugated pipe 20 is manufactured. Since the corrugated pipe 20 is sucked by the corrugated mold, a gap is formed between the mountain portion 22 and the corrugated member 32. On the other hand, a part of the valley portion 24 and the corrugated member 32 are in contact with each other.

[Action and effect]
Next, the operation and effect of the composite pipe 10 according to the first embodiment will be described.

When the composite pipe 10 shown in FIG. 5 is connected to a joint member (not shown), it is necessary to shorten the corrugated pipe 20 and the holding portion 30 in the Z direction to expose the end portion of the inner pipe 12. At the end of the composite pipe 10 in the Z direction, as an example, it is assumed that the end face of the corrugated pipe 20 and the end face of the inner pipe 12 are aligned at substantially the same position in the Z direction. The inner pipe 12 is held inside the corrugated pipe 20 by the holding portion 30.

The Z-direction end (left end in the figure) of the corrugated pipe 20 shown in FIG. 6 is moved to one side in the Z direction (the side away from the end of the inner pipe 12 <right side in the figure>) to Z. The mountain portions 22 adjacent to each other in the direction are deformed so as to approach each other, and the corrugated pipe 20 is shortened in the Z direction. In this case, the holding portion 30 (four corrugated members 32) is elastically deformed as the corrugated pipe 20 expands and contracts (shortens), so that the holding portion 30 (four corrugated members 32) is shortened in the Z direction. That is, since the corrugated pipe 20 and the holding portion 30 are shortened in the Z direction, the end portion of the inner pipe 12 in the Z direction is exposed.

As described above, according to the composite pipe 10, the holding portion 30 holds the inner pipe 12 so that the inner pipe 12 can be held inside the corrugated pipe 20. Further, when the corrugated pipe 20 is expanded and contracted along the Z direction of the inner pipe 12, the holding portion 30 is elastically deformed in the Z direction as the corrugated pipe 20 expands and contracts. Here, since the holding portion 30 has the linear corrugated member 32 and the expansion / contraction direction of the corrugated tube 20 and the elastic deformation direction of the corrugated member 32 are aligned, the expansion / contraction of the corrugated tube 20 is aligned with the holding portion 30. It becomes difficult to be disturbed by. That is, in the composite pipe 10 that holds the inner pipe 12 inside the corrugated pipe 20, the inner pipe 12 can be held inside the corrugated pipe 20 and the corrugated pipe 20 can be easily moved with respect to the inner pipe 12. ..

Further, according to the composite pipe 10, when the holding portion 30 is elastically deformed in the Z direction, the frictional resistance acting on the contact portion between the holding portion 30 and the corrugated pipe 20 is generated between the holding portion 30 and the inner pipe 12. It is larger than the frictional resistance acting on the contact part. Here, since the frictional resistance acting on the contact portion between the holding portion 30 and the corrugated pipe 20 is large, the holding portion 30 is easily elastically deformed as the corrugated pipe 20 expands and contracts, so that the corrugated pipe 20 and the holding portion 30 are easily deformed. And can be easily deformed together. Further, since the frictional resistance acting on the contact portion between the holding portion 30 and the inner pipe 12 is small, it becomes difficult for the holding portion 30 to stay on the outer peripheral surface 13 of the inner pipe 12, so that the corrugated pipe 20 and the holding portion 30 are connected to the inner pipe. It becomes easy to move relative to 12. Due to these actions, the corrugated pipe 20 can be made easier to move with respect to the inner pipe 12.

Further, according to the composite pipe 10, the first contact area SA (see FIG. 4) is smaller than the second contact area SB (see FIG. 4), so that the frictional resistance between the holding portion 30 and the outer peripheral surface 13 is maintained. It may be smaller than the frictional resistance between the portion 30 and the corrugated tube 20. As a result, the frictional resistance acting on the contact portion between the holding portion 30 and the inner pipe 12 may be reduced, and the holding portion 30 is less likely to stay on the outer peripheral surface 13 of the inner pipe 12, so that the corrugated pipe 20 and the holding portion The 30 can be easily moved relative to the inner tube 12.

Further, according to the composite pipe 10, since the shape of the corrugated member 32 is such that the inner pipe 12 can be easily expanded and contracted in the Z direction, the corrugated pipe 20 and the holding portion 30 can be easily deformed integrally. Further, since a plurality of (four as an example) corrugated members 32 are arranged at intervals in the circumferential direction of the inner pipe 12, the corrugated members 32 hold the inner pipe 12 as compared with one configuration. Since the number of the inner tubes 12 is increased, the holding state of the inner tube 12 can be stabilized. That is, it is possible to suppress the expansion and contraction of the corrugated pipe 20 from being hindered and to stabilize the holding state of the inner pipe 12.

Further, according to the composite pipe 10, the corrugated pipe 20 is configured to repeat the mountain portion 22 and the valley portion 24 in the Z direction, so that the force is smaller than that in the configuration in which the corrugated pipe 20 extends linearly. The corrugated tube 20 can be deformed in the Z direction. As a result, the corrugated pipe 20 can be easily expanded and contracted in the Z direction.

[Second Embodiment]
As an example of the present disclosure, the composite pipe 40 according to the second embodiment will be described. The same components as those of the composite pipe 10 of the first embodiment are designated by the same reference numerals as those of the composite pipe 10, and the description thereof will be omitted.

The composite pipe 40 shown in FIG. 7 has an inner pipe 12, a corrugated pipe 20, and a holding portion 50. The configuration of the composite pipe 40 other than the holding portion 50 is the same as that of the composite pipe 10 (see FIG. 1).

<Holding part>
The holding portion 50 is configured as a separate body from the inner pipe 12 and the corrugated pipe 20. Further, the holding portion 50 has one spiral member 52 as an example.

The spiral member 52 is an example of a linear member, and extends linearly in the Z direction between the inner pipe 12 and the corrugated pipe 20 in the D direction of the inner pipe 12. Specifically, the spiral member 52 is spirally wound around the outer peripheral surface 13 of the inner pipe 12. Further, the length of one pitch of the spiral member 52 in the Z direction is, for example, longer than the length of one cycle of the mountain portion 22 and the valley portion 24 in the Z direction. The spiral member 52 is sandwiched between the inner pipe 12 and the corrugated pipe 20 in the D direction of the inner pipe 12. As a result, the spiral member 52 holds the inner pipe 12 inside the corrugated pipe 20.

Further, the spiral member 52 is made of an elastomer. Examples of the elastomer include ethylene propylene diene rubber and silicone rubber. Among them, it is preferable to use silicone rubber.

Further, the spiral member 52 is formed in a coil spring shape. That is, the spiral member 52 is formed so as to be elastically deformable in the Z direction. The spiral member 52 is configured to be elastically deformed in the Z direction as the corrugated tube 20 expands and contracts in the Z direction. In addition, the spiral member 52 is formed in a tubular shape having a rectangular portion 33 and a semicircular portion 34, similarly to the corrugated member 32 (see FIG. 3). The outer end surface 33A of the rectangular portion 33 is in contact with a part of the inner surface 25. The inner end surface 34A of the semicircular portion 34 is in contact with a part of the outer peripheral surface 13. The spiral member 52 may be arranged in the composite pipe 40 by inserting a preformed spiral member 52 between the inner pipe 12 and the corrugated pipe 20, or the inner pipe 12 and the corrugated pipe 20 may be arranged. It may be arranged in the composite pipe 40 by being formed between them.

The frictional resistance between the holding portion 50 and the outer peripheral surface 13 is made smaller than the frictional resistance between the holding portion 50 and the inner surface 25 of the corrugated pipe 20. In the present disclosure, "the frictional resistance between the holding portion 50 and the outer peripheral surface 13 is small" means that the holding portion 50 is relatively slippery in the Z direction with respect to the outer peripheral surface 13. Further, "the frictional resistance between the holding portion 50 and the inner surface 25 is large" means that the holding portion 50 is easily expanded and contracted together with the corrugated pipe 20 as the corrugated pipe 20 moves in the Z direction.

The first contact area SA (see FIG. 4) between the holding portion 50 and the outer peripheral surface 13 is smaller than the second contact area SB (see FIG. 4) between the holding portion 50 and the corrugated pipe 20.

[Action and effect]
Next, the operation and effect of the composite pipe 40 according to the second embodiment will be described. The description of the same operation as that of the first embodiment may be omitted.

When the composite pipe 40 shown in FIG. 7 is connected to a joint member (not shown), it is necessary to shorten the corrugated pipe 20 and the holding portion 50 in the Z direction to expose the end portion of the inner pipe 12. The inner pipe 12 is held inside the corrugated pipe 20 by the holding portion 50.

By moving the end portion of the corrugated pipe 20 shown in FIG. 8 in the Z direction (left end portion in the drawing) to one side in the Z direction (right side in the drawing), the corrugated pipe 20 is shortened in the Z direction. In this case, the holding portion 50 (one spiral member 52) is elastically deformed as the corrugated tube 20 expands and contracts (shortens), so that the holding portion 50 (one spiral member 52) is shortened in the Z direction. That is, since the corrugated pipe 20 and the holding portion 30 are shortened in the Z direction, the end portion of the inner pipe 12 in the Z direction is exposed.

As described above, according to the composite pipe 40, the holding portion 50 holds the inner pipe 12 so that the inner pipe 12 can be held inside the corrugated pipe 20. Further, when the corrugated pipe 20 is expanded and contracted along the Z direction of the inner pipe 12, the holding portion 50 is elastically deformed in the Z direction as the corrugated pipe 20 expands and contracts. Here, since the holding portion 50 has the linear spiral member 52 and the expansion / contraction direction of the corrugated tube 20 and the elastic deformation direction of the spiral member 52 are aligned, the expansion / contraction of the corrugated tube 20 is aligned with the holding portion 50. It becomes difficult to be disturbed by. That is, in the composite pipe 40 that holds the inner pipe 12 inside the corrugated pipe 20, the inner pipe 12 can be held inside the corrugated pipe 20 and the corrugated pipe 20 can be easily moved with respect to the inner pipe 12. ..

Further, according to the composite pipe 40, when the holding portion 50 is elastically deformed in the Z direction, the frictional resistance acting on the contact portion between the holding portion 50 and the corrugated pipe 20 is caused between the holding portion 50 and the inner pipe 12. It is larger than the frictional resistance acting on the contact part. Here, since the frictional resistance acting on the contact portion between the holding portion 50 and the corrugated pipe 20 is large, the holding portion 50 is easily elastically deformed as the corrugated pipe 20 expands and contracts, so that the corrugated pipe 20 and the holding portion 50 are easily deformed. And can be easily deformed together. Further, since the frictional resistance acting on the contact portion between the holding portion 50 and the inner pipe 12 is small, it becomes difficult for the holding portion 50 to stay on the outer peripheral surface 13 of the inner pipe 12, so that the corrugated pipe 20 and the holding portion 50 are connected to the inner pipe. It becomes easy to move relative to 12. Due to these actions, the corrugated pipe 20 can be made easier to move with respect to the inner pipe 12.

Further, according to the composite pipe 40, since the first contact area SA (see FIG. 4) is smaller than the second contact area SB (see FIG. 4), the frictional resistance between the holding portion 50 and the outer peripheral surface 13 is maintained. It may be smaller than the frictional resistance between the portion 30 and the corrugated tube 20. As a result, the frictional resistance acting on the contact portion between the holding portion 50 and the inner pipe 12 may be reduced, and the holding portion 50 is difficult to stay on the outer peripheral surface 13 of the inner pipe 12, so that the corrugated pipe 20 and the holding portion The 50 can be easily moved relative to the inner tube 12.

Further, according to the composite pipe 40, since the shape of the spiral member 52 is such that the inner pipe 12 can be easily expanded and contracted in the Z direction, the corrugated pipe 20 and the holding portion 50 can be easily deformed integrally. Further, since the inner pipe 12 can be held by only one of the spiral members 52, the number of parts of the holding portion 50 can be reduced. That is, it is possible to suppress the expansion and contraction of the corrugated pipe 20 from being hindered, and to reduce the number of members constituting the composite pipe 40.

[Third Embodiment]
As an example of the present disclosure, the composite pipe 60 according to the third embodiment will be described. The same components as those of the composite pipe 10 of the first embodiment are designated by the same reference numerals as those of the composite pipe 10, and the description thereof will be omitted.

The composite pipe 60 shown in FIG. 9 has an inner pipe 12, a corrugated pipe 20, and a holding portion 70. The configuration of the composite pipe 60 other than the holding portion 70 is the same as that of the composite pipe 10 (see FIG. 1).

<Holding part>
The holding portion 70 is configured as a separate body from the inner pipe 12 and the corrugated pipe 20. Further, the holding portion 70 has one net-like member 72 as an example.

The net-like member 72 is an example of a linear member, and extends linearly in the Z direction between the inner pipe 12 and the corrugated pipe 20 in the D direction of the inner pipe 12. Since the net-like member 72 is a member that comes into contact with a part of the outer peripheral surface 13 of the inner pipe 12 and a part of the inner surface 25 of the corrugated pipe 20, "the outer peripheral surface 13 and the inner surface 25 are planarized (overall). It is not a member that is "contacted". Here, the reticulated member 72 includes at least one of a straight line and a curved line. That is, in the present disclosure, the "reticulated member" is a concept included in the "linear member".

Specifically, the net-like member 72 covers the outer peripheral surface 13 of the inner pipe 12 in the circumferential direction. The net-like member 72 is sandwiched between the inner pipe 12 and the corrugated pipe 20 in the D direction of the inner pipe 12. As a result, the net-like member 72 holds the inner pipe 12 inside the corrugated pipe 20. Further, the net-like member 72 is made of an elastomer. Examples of the elastomer include ethylene propylene diene rubber and silicone rubber. Among them, it is preferable to use silicone rubber.

Further, the net-like member 72 is formed in a net-like shape in which the vertices of a plurality of waveforms having amplitudes in the intersecting direction intersecting the Z-axis direction are joined when viewed from the D direction. As an example, the network member 72 is formed in a network in which a plurality of corrugated members 32 (see FIG. 1) are arranged so as to be adjacent to each other in the circumferential direction of the inner pipe 12, and the vertices of the plurality of corrugated members 32 are joined in the circumferential direction. Has been done. That is, the net-like member 72 is formed so as to be elastically deformable in the Z direction. The net-like member 72 is configured to be elastically deformed in the Z direction as the corrugated pipe 20 expands and contracts in the Z direction.

Similar to the corrugated member 32 (see FIG. 3), the net-like member 72 is formed in a tubular shape having a rectangular portion 33 and a semicircular portion 34. The outer end surface 33A of the rectangular portion 33 is in contact with a part of the inner surface 25. The inner end surface 34A of the semicircular portion 34 is in contact with a part of the outer peripheral surface 13.

The frictional resistance between the holding portion 70 and the outer peripheral surface 13 is smaller than the frictional resistance between the holding portion 70 and the inner surface 25 of the corrugated pipe 20. In the present disclosure, "the frictional resistance between the holding portion 70 and the outer peripheral surface 13 is small" means that the holding portion 70 is relatively slippery in the Z direction with respect to the outer peripheral surface 13. Further, "the frictional resistance between the holding portion 70 and the inner surface 25 is large" means that the holding portion 70 is easily expanded and contracted together with the corrugated pipe 20 as the corrugated pipe 20 moves in the Z direction.

The first contact area SA (see FIG. 4) between the holding portion 70 and the outer peripheral surface 13 is smaller than the second contact area SB (see FIG. 4) between the holding portion 70 and the corrugated pipe 20.

[Action and effect]
Next, the operation and effect of the composite pipe 60 according to the third embodiment will be described. The description of the same operation as that of the first embodiment may be omitted.

When the composite pipe 60 shown in FIG. 9 is connected to a joint member (not shown), it is necessary to shorten the corrugated pipe 20 and the holding portion 70 in the Z direction to expose the end portion of the inner pipe 12. The inner pipe 12 is held inside the corrugated pipe 20 by the holding portion 70.

By moving the end portion of the corrugated pipe 20 shown in FIG. 10 in the Z direction (left end portion in the drawing) to one side in the Z direction (right side in the drawing), the corrugated pipe 20 is shortened in the Z direction. In this case, the holding portion 70 (one net-like member 72) is elastically deformed as the corrugated pipe 20 expands and contracts (shortens), so that it is shortened in the Z direction. That is, since the corrugated pipe 20 and the holding portion 70 are shortened in the Z direction, the end portion of the inner pipe 12 in the Z direction is exposed.

As described above, according to the composite pipe 60, the holding portion 70 holds the inner pipe 12 so that the inner pipe 12 can be held inside the corrugated pipe 20. Further, when the corrugated pipe 20 is expanded and contracted along the Z direction of the inner pipe 12, the holding portion 70 is elastically deformed in the Z direction as the corrugated pipe 20 expands and contracts. Here, since the holding portion 70 has the linear mesh member 72, the expansion / contraction direction of the corrugated tube 20 and the elastic deformation direction of the mesh member 72 are aligned, so that the expansion / contraction of the corrugated tube 20 is aligned with the holding portion 70. It becomes difficult to be disturbed by. That is, in the composite pipe 60 that holds the inner pipe 12 inside the corrugated pipe 20, the inner pipe 12 can be held inside the corrugated pipe 20 and the corrugated pipe 20 can be easily moved with respect to the inner pipe 12. ..

Further, according to the composite pipe 60, when the holding portion 70 is elastically deformed in the Z direction, the frictional resistance acting on the contact portion between the holding portion 70 and the corrugated pipe 20 is generated between the holding portion 70 and the inner pipe 12. It is larger than the frictional resistance acting on the contact part. Here, since the frictional resistance acting on the contact portion between the holding portion 70 and the corrugated pipe 20 is large, the holding portion 70 is easily elastically deformed as the corrugated pipe 20 expands and contracts, so that the corrugated pipe 20 and the holding portion 70 are easily deformed. And can be easily deformed together. Further, since the frictional resistance acting on the contact portion between the holding portion 70 and the inner pipe 12 is small, it becomes difficult for the holding portion 70 to stay on the outer peripheral surface 13 of the inner pipe 12, so that the corrugated pipe 20 and the holding portion 70 are connected to the inner pipe. It becomes easy to move relative to 12. Due to these actions, the corrugated pipe 20 can be made easier to move with respect to the inner pipe 12.

Further, according to the composite pipe 60, since the first contact area SA (see FIG. 4) is smaller than the second contact area SB (see FIG. 4), the frictional resistance between the holding portion 70 and the outer peripheral surface 13 is maintained. It may be smaller than the frictional resistance between the portion 70 and the corrugated tube 20. As a result, the frictional resistance acting on the contact portion between the holding portion 70 and the inner pipe 12 may be reduced, and the holding portion 70 is less likely to stay on the outer peripheral surface 13 of the inner pipe 12, so that the corrugated pipe 20 and the holding portion The 70 can be easily moved relative to the inner tube 12.

Further, according to the composite pipe 60, the shape of the mesh member 72 is such that the inner pipe 12 can be easily expanded and contracted in the Z direction, so that the corrugated pipe 20 and the holding portion 70 can be easily deformed integrally. Further, since the net-like member 72 covers the outer peripheral surface 13 of the inner pipe 12 in the circumferential direction, when the corrugated pipe 20 is rotated (twisted) around the central axis, it becomes the outer peripheral surface 13 of the inner pipe 12. It is possible to prevent the contact portion with the net-like member 72 from being biased to a part of the inner pipe 12 in the circumferential direction. That is, it is possible to suppress the expansion and contraction of the corrugated pipe 20 from being hindered, and also to suppress the bias of the holding portion 70 when the corrugated pipe 20 is twisted.

The present invention is not limited to the above embodiment.

<First modification>
In FIG. 11, a composite pipe 80 is shown as a first modification. The composite pipe 80 has an inner pipe 12, an outer pipe 82 as an example of a coating layer, and a holding portion 30. The outer pipe 82 is formed in the corrugated pipe 20 (see FIG. 2) in a cylindrical shape (flattened) excluding the peak portion 22 and the valley portion 24 (see FIG. 2). Further, the outer tube 82 is made of an elastomer. Examples of the elastomer include ethylene propylene diene rubber and silicone rubber. A part of the outer tube 82 and the holding portion 30 are in contact with each other in the D direction.

By moving the end portion of the outer pipe 82 in the Z direction (left end portion in the drawing) to one side in the Z direction (right side in the drawing), the outer pipe 82 is shortened in the Z direction. In this case, the holding portion 30 is elastically deformed in the Z direction as the outer tube 82 expands and contracts (shortens), so that the holding portion 30 is shortened in the Z direction. That is, since the outer tube 82 and the holding portion 30 are shortened in the Z direction, the end portion of the inner tube 12 in the Z direction is exposed. As described above, as an example of the coating layer, a tube without a bellows portion may be used.

<Second modification>
FIG. 12 shows a cross section of the corrugated member 92 as a second modification. The corrugated member 92 is formed as a solid member as an example of a linear member. Further, the shape of the corrugated member 92 is such that the trapezoidal portion 94 and the semicircular portion 34 are integrated when viewed from the central axis direction of the corrugated member 92. The cross section orthogonal to the central axis of the corrugated member 92 is referred to as a cross section S2. In the cross section S2, the trapezoidal portion 94 and the semicircular portion 34 are arranged side by side in the D direction. Further, the outer end surface 94A (the surface corresponding to the lower base of the trapezoid) of the trapezoidal portion 94 in the D direction is a plane orthogonal to the D direction and is in contact with a part of the inner surface 25. The inner end surface 34A is in contact with a part of the outer peripheral surface 13. As described above, by having the trapezoidal portion 94, the contact area on the inner surface 25 side is increased as compared with the rectangular portion 33 (see FIG. 3), so that the corrugated member 92 can be further easily moved with the movement of the corrugated pipe 20. can do. In FIG. 12, hatching is omitted in order to show the cross-sectional shape of the corrugated member 92 in an easy-to-understand manner.

<Other variants>
In the composite pipe 10, the frictional resistance between the holding portion 30 and the outer peripheral surface 13 may be the same as the frictional resistance between the holding portion 30 and the corrugated pipe 20. Further, the first contact area SA may be the same as the second contact area SB or smaller than the second contact area SB.

In the composite pipe 40, the frictional resistance between the holding portion 50 and the outer peripheral surface 13 may be the same as the frictional resistance between the holding portion 50 and the corrugated pipe 20. Further, the first contact area SA may be the same as the second contact area SB or smaller than the second contact area SB. Further, the outer pipe 82 may be used instead of the corrugated pipe 20.

In the composite pipe 60, the frictional resistance between the holding portion 70 and the outer peripheral surface 13 may be the same as the frictional resistance between the holding portion 70 and the corrugated pipe 20. Further, the first contact area SA may be the same as the second contact area SB or smaller than the second contact area SB. Further, the outer pipe 82 may be used instead of the corrugated pipe 20.

Arbitrary number of corrugated members 32 can be arranged in the circumferential direction of the inner pipe 12. For example, a total of three corrugated members 32 may be arranged at approximately 120 degrees in the circumferential direction. However, in order to secure the holding force of the inner pipe 12, it is preferable to provide three or more corrugated members 32. Further, the magnitude of the wave amplitude of the corrugated member 32 is not limited to the same magnitude in the Z direction, but may be different.

The corrugated tube 20 is not limited to having a rectangular corrugated cross section, and may be formed, for example, having a triangular corrugated shape.

The coating layer may have a tubular portion that covers the tubular body and a spiral portion that is formed on the inner peripheral surface of the tubular portion and protrudes toward the tubular body. In this case, the holding portion may have ring members that are annular when viewed from the Z direction and are arranged at intervals in the Z direction.

Although the composite pipes according to each embodiment and each modification of the present invention have been described above, each of these embodiments and each modification may be used in combination as appropriate, and as long as the gist of the present invention is not deviated. Of course, it can be carried out in various embodiments.

10 ... Composite pipe, 12 ... Inner pipe (example of pipe body), 13 ... Outer surface, 20 ... Corrugated pipe (example of coating layer), 22 ... Mountain part, 24 ... Valley part, 30 ... Holding part, 32 ... Waveform Member (example of linear member), 40 ... composite pipe, 50 ... holding part, 52 ... spiral member (example of linear member), 60 ... composite pipe, 70 ... holding part, 72 ... net-like member (linear member) Example), 80 ... composite pipe, 82 ... outer pipe (example of coating layer), 92 ... corrugated member (example of linear member), SA ... first contact area, SB ... second contact area

Claims (7)

With the tube
A coating layer formed in a tubular shape, covering the outer peripheral surface of the tubular body, and expanding and contracting in the axial direction of the tubular body,
It has a linear member that is arranged between the tubular body and the coating layer and is elastically deformed in the axial direction as the coating layer expands and contracts, and holds the tubular body inside the coating layer. With the holding part
Composite pipe with. The composite pipe according to claim 1, wherein the frictional resistance between the holding portion and the outer peripheral surface is smaller than the frictional resistance between the holding portion and the coating layer. The composite pipe according to claim 2, wherein the first contact area between the holding portion and the outer peripheral surface is smaller than the second contact area between the holding portion and the covering layer. Claims 1 to claim 1 to the linear member, which is a plurality of corrugated members arranged at intervals in the circumferential direction of the tubular body and formed in a waveform having an amplitude in an intersecting direction intersecting the axial direction. The composite tube according to any one of 3. The composite pipe according to any one of claims 1 to 3, wherein the linear member is a spiral member spirally wound around the outer peripheral surface of the pipe body. Claims 1 to 3 are claims 1 to 3, wherein the linear member is a network member formed in a network shape in which a plurality of waveform vertices having amplitudes in an intersecting direction intersecting the axial direction are joined and covering the outer peripheral surface in the circumferential direction. The composite tube according to any one of the above. The composite pipe according to any one of claims 1 to 6, wherein the coating layer is a corrugated pipe that repeats peaks and valleys in the axial direction.