JP7274934B2 - Composite pipe - Google Patents

Description

The present invention relates to composite pipes.

In Patent Document 1, a composite having a tubular body, a flexible protective layer covering the outer peripheral surface of the tubular body and having valleys formed on the inner peripheral surface, and a holding layer covering the outer peripheral surface of the protective layer A tube is disclosed.

JP 2013-231490 A

By the way, in a composite pipe in which a tubular body is held inside a coating layer, in a configuration in which another member is closely attached to 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. There is room for improvement since other members may interfere with the expansion and contraction of the coating layer when it is allowed to move.

An object of the present invention is to provide a composite pipe in which a tubular body is held inside a covering layer, in which the tubular body is held inside the covering layer and the covering layer can be easily expanded and contracted with respect to the tubular body. with the aim of obtaining

A composite pipe according to a first aspect includes a tubular body, a tubular covering layer that covers an outer peripheral surface of the tubular body and is capable of expanding and contracting in the axial direction of the tubular body, and the tubular body and the covering layer. and a holding portion disposed between and having a linear member that is elastically deformed in the axial direction as the covering layer expands and contracts, and that holds the tubular body inside the covering layer.

According to the composite pipe according to the first aspect, the tubular body can be held inside the coating layer by the tubular body being held by the holding portion. Furthermore, when the covering layer is expanded and contracted along the axial direction of the tubular body, the holding portion is elastically deformed in the axial direction along with the expansion and contraction of the covering layer. Here, since the holding section has the linear member and the expansion and contraction direction of the covering layer and the elastic deformation direction of the linear member are aligned, the expansion and contraction of the covering layer is less likely to be hindered by the holding section. In other words, in the composite tube that holds the tubular body inside the covering layer, the tubular body can be held inside the covering layer and the covering layer can be easily moved with respect to the tubular body.

The frictional resistance between the retaining portion and the outer peripheral surface of the composite pipe according to the second aspect is smaller than the frictional resistance between the retaining 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 tubular body. greater than the acting frictional resistance. Here, since the frictional resistance acting on the contact portion between the holding portion and the covering layer is large, the holding portion is likely to be elastically deformed as the covering layer expands and contracts. becomes easier. Furthermore, since the frictional resistance acting on the contact portion between the holding part and the tubular body is small, it becomes difficult for the holding part to remain on the outer peripheral surface of the tubular body. It becomes easier to let These actions make it easier to move the coating layer relative to the tubular body.

A first contact area between the holding portion and the outer peripheral surface of the composite pipe according to the third aspect is smaller than a second contact area between the holding portion and the coating 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. may become. As a result, there is a possibility that the frictional resistance that acts on the contact portion between the holding part and the tubular body will be reduced, making it difficult for the holding part to stay on the outer peripheral surface of the tubular body. It can be made relatively easy to move.

The linear members of the composite pipe according to the fourth aspect are a plurality of wavy members arranged at intervals in the circumferential direction of the tubular body and formed into a wavy shape having amplitude in an intersecting direction that intersects with 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 is easy to expand and contract in the axial direction of the pipe body, it is easy to integrally deform the covering layer and the holding portion. Furthermore, since the plurality of corrugated members are spaced apart in the circumferential direction of the tubular body, the number of locations for holding the tubular body increases compared to a configuration in which only one corrugated member is provided. The holding state can be stabilized. That is, it is possible to prevent 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 tube according to the fifth aspect is a spiral member spirally wound around the outer peripheral surface of the tubular body.

According to the composite pipe according to the fifth aspect, the shape of the helical member is such that it is easy to expand and contract in the axial direction of the pipe, so that the coating layer and the holding portion are easily deformed integrally. Furthermore, since it is possible to hold the tubular body with one helical member, the number of parts of the holding portion can be reduced. In other words, it is possible to prevent the expansion and contraction of the coating layer from being hindered, and to reduce the number of members constituting the composite pipe.

The linear member of the composite pipe according to the sixth aspect is a mesh member that is formed in a mesh shape by joining a plurality of corrugated vertices having amplitude in a direction that intersects the axial direction and that covers the outer peripheral surface in the circumferential direction. be.

According to the composite pipe according to the sixth aspect, since the shape of the net-like member is such that it is easy to expand and contract in the axial direction of the pipe, it is easy to integrally deform the covering layer and the holding portion. Furthermore, 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, biasing toward a part of the tubular body in the circumferential direction is suppressed. In other words, it is possible to prevent the expansion and contraction of the coating layer from being hindered, and to prevent the holding portion from becoming biased when the coating layer is twisted.

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

According to the composite pipe according to the seventh aspect, since the coating layer has a configuration in which peaks and valleys are repeated in the axial direction, the coating can be coated with less force than in a configuration in which the coating layer extends linearly. Since the layer can be deformed in the axial direction, the covering layer can be easily expanded and contracted in the axial direction.

According to the present invention, there is provided a composite pipe in which a tubular body is held inside a covering layer, in which the tubular body can be held inside the covering layer and the covering layer can be easily expanded and contracted with respect to the tubular body. Obtainable.

1 is a perspective view showing a composite pipe according to a first embodiment; FIG. 2 is a longitudinal sectional view of part of the corrugated tube shown in FIG. 1; FIG. FIG. 2 is a vertical cross-sectional view of a section perpendicular to the central axis of the corrugated member shown in FIG. 1; 1. It is explanatory drawing at the time of seeing the contact part of the corrugated pipe|tube shown by FIG. 1, and a corrugated member, and the contact part of a corrugated member, and an inner pipe from the radial direction outer side of an inner pipe. FIG. 2 is a perspective view showing a completed state of the composite pipe shown in FIG. 1; Fig. 5 is a perspective view showing a 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. FIG. 9 is a perspective view showing a state in which the corrugated tube in the composite tube shown in FIG. 8 is contracted in the axial direction; It is explanatory drawing which shows the composite pipe which concerns on 3rd Embodiment. FIG. 10 is a perspective view showing a state in which the corrugated tube in the composite tube shown in FIG. 9 is contracted in the axial direction; It is a perspective view which shows the composite pipe which concerns on a 1st modification. It is a longitudinal cross-sectional view of the cross section orthogonal to the central axis in the wave member which concerns on a 2nd modification.

[First embodiment]
As an example of the present disclosure, a composite pipe 10 according to the first embodiment will be described. Components shown using the same reference numerals in each drawing mean the same components. In each embodiment described below, overlapping descriptions and reference numerals may be omitted.

As used herein, the amount of each component in the composition refers to the total amount of the multiple substances present in the composition unless otherwise specified when multiple substances corresponding to each component are present in the composition. means As used herein, the term "main component" refers to the component with the highest mass-based content in the mixture, unless otherwise specified.

A composite pipe 10 shown in FIG. 30. The composite pipe 10 is configured as an elongated member that is long in the axial direction, and is cut in a direction orthogonal to the axial direction to match the required length. The connection between the one composite pipe 10 and the other composite pipe 10 is achieved by connecting the one inner pipe 12 and the other inner pipe 12 with the corrugated pipe 20 contracted (with the inner pipe 12 exposed). It is done by connecting with a tubular joint member that is not connected.

<Inner tube>
The inner tube 12 is made of a resin material and has a cylindrical shape. In addition, the inner tube 12 is configured as an elongated member that is 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. Furthermore, the radial direction of the inner tube 12 is called the D direction. The Z direction is also the axial direction of the composite tube 10 . The central axis K of the inner tube 12 is also the central axis of the composite tube 10 . Inner tube 12 has an outer peripheral surface 13 .

Examples of the resin material forming the inner tube 12 include polyolefins such as polybutene, polyethylene, crosslinked polyethylene, and polypropylene, and vinyl chloride. One type or two or more types of resin may be used for the inner tube 12 . Polybutene is preferably used for the inner tube 12, and preferably contains polybutene as a main component. For example, it is more preferable that the resin material forming the inner tube 12 contains 85% by mass or more of polybutene. The resin material forming the inner tube 12 may contain additives. Note that the inner tube 12 is not expanded and 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 12 mm or more and 35 mm or less. The thickness of the inner tube 12 is not particularly limited, but may be, for example, 1.0 mm or more and 5.0 mm or less, preferably 1.4 mm or more and 3.2 mm or less.

<Corrugated pipe>
The corrugated tube 20 shown in FIG. 2 has an inner diameter larger than the outer diameter of the inner tube 12, and covers the outer peripheral surface 13 of the inner tube 12 when viewed from the outside in the D direction. In other words, the corrugated tube 20 is configured as the outer tube of the composite tube 10 . In addition, the corrugated tube 20 and the inner tube 12 are arranged (coaxially) with the central axis K thereof aligned. Furthermore, the corrugated pipe 20 and the inner pipe 12 are arranged with a gap in the D direction. The Z-direction length of the corrugated pipe 20 is set to be substantially the same as the Z-direction length of the inner pipe 12 . 2, illustration of the holding portion 30 (see FIG. 1) is omitted.

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

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. If the MFR is greater than 1.2, the molten resin tends to flow into the parting surface of the mold for forming the corrugated pipe 20, and burrs tend to occur. The resin material forming the corrugated pipe 20 may contain other additives.

Further, the corrugated pipe 20 is formed in a bellows shape in which annular peaks 22 and annular valleys 24 are repeated in the Z direction, and is expandable (extendable and shortenable) in the Z direction. Specifically, when viewed from a direction orthogonal to the Z direction, the corrugated pipe 20 has peaks 22 that bulge outward in the D direction and valleys 24 that dent inward in the D direction alternately in the Z direction. It has a continuously formed structure. The outermost portion in the D direction of the corrugated pipe 20 is the outer wall 22A, the innermost portion in the D direction is the inner wall 24A, and the intermediate portion between the outer wall 22A and the inner wall 24A in the D direction is the boundary M. Here, with respect to the boundary M, the outside portion in the D direction is the peak portion 22 and the inside portion in the D direction is the valley portion 24 . A surface of the inner wall 24</b>A on the inner side 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 tube 20 .

As an example, the peaks 22 and the valleys 24 are formed in a substantially rectangular wave shape when viewed from a direction orthogonal to the D direction and the Z direction. In other words, the outer wall 22A and the inner 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 peak portion 22 in the Z direction is set longer than the length of one valley portion 24 in the Z direction. In addition, the length in the Z direction of one peak portion 22 is 1.2 times the length in the Z direction of one valley portion 24 in order to ensure that the outer wall 22A is easily deformed during shortening deformation. It is preferable that it is above.

Moreover, it is preferable that the length in the Z direction of one valley portion 24 is 0.8 mm or more. This is because if the length of one trough 24 in the Z direction is less than 0.8 mm, the width of the trough of the mold for manufacturing the corrugated pipe 20 is too small, so that the portion of the mold corresponding to the trough is This is because the corrugated pipe 20 becomes fragile and difficult to form. On the other hand, the Z-direction length of one peak portion 22 is preferably five times or less the Z-direction length of one valley portion 24 . This is because the flexibility of the composite tube 10 can be maintained. In addition, if the Z-direction length of one crest 22 is too long, when laying the composite pipe 10, the contact area with the ground becomes large, making construction difficult.

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 wall 22A is, for example, thinner than the thickness of the inner wall 24A. The thickness of the outer wall 22A is preferably 0.9 times or less the thickness of the inner wall 24A in order to ensure that the outer wall 22A deforms easily during shortening deformation.

The length corresponding to the difference between the outer wall 22A and the inner wall 24A in the D direction (hereinafter referred to as the 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 portions of the peaks 22 along the Z direction are not deformed, the valleys 24 do not bulge outward in the D direction during contraction, and the adjacent peaks 22 do not come close to each other. It is difficult to be in a distorted state. When the radius difference is 800% or less of the average thickness of the corrugated pipe 20, in order to suppress the above deformation state, the length of the peaks 22 in the Z direction is 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 tube 20 (the outer diameter of the outermost part) is not particularly limited, but can be set, for example, in the range of 13 mm or more and 130 mm or less.

<Holding part>
The holding part 30 shown in FIG. 1 is configured separately from the inner tube 12 and the corrugated tube 20 . Moreover, the holding part 30 has four wave members 32 as an example. The four corrugated members 32 are circumferentially spaced around the inner tube 12 . The configurations of the four corrugated members 32 are identical.

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. In other words, a "linear member" means a member having a shape including at least one of a straight portion and a curved 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 in contact with a portion of the outer peripheral surface 13 of the inner pipe 12 and the inner surface 25 of the corrugated pipe 20 . means a state in which only a part of the Conversely, "a state in which the corrugated member 32 is in planar contact with the inner tube 12 and the corrugated tube 20" means that the corrugated member 32 contacts the entire outer peripheral surface 13 of the inner tube 12 and the entire inner surface 25 of the corrugated tube 20. means the state of 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 . The corrugated member 32 thereby holds the inner tube 12 inside the corrugated tube 20 .

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

Further, the wavy member 32 is formed in a sine wave shape with the Z direction as an advancing direction, as an example, when viewed from the D direction of the inner pipe 12 . In other words, the corrugated member 32 is formed in a corrugated shape having amplitude in the orthogonal direction orthogonal to the Z direction when viewed from the D direction of the inner pipe 12 . The orthogonal direction is an example of a cross direction. Thus, the wave member 32 is formed 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 pipe 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 wave member 32 is a shape in which a rectangular portion 33 and a semicircular portion 34 are integrated when viewed from the central axis direction of the wave member 32 . A cross section orthogonal to the central axis of the wave 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. An outer end face 33A of the rectangular portion 33 in the D direction is a plane perpendicular to the D direction and is in contact with a portion of the inner surface 25 . An inner end surface 34</b>A of the semicircular portion 34 in the direction D (the curved surface located at the apex portion of the semicircle) is in contact with a portion of the outer peripheral surface 13 . In addition, in FIG. 3, hatching is omitted in order to show the cross-sectional shape of the wave member 32 in an easy-to-understand manner.

The frictional resistance between the holding portion 30 and the outer peripheral surface 13 is made smaller than the frictional resistance between the holding portion 30 and the inner surface 25 of the corrugated tube 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 slides relatively easily 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 shows a schematic view of a portion of the outer peripheral surface 13, a portion of the corrugated member 32, and a portion of the corrugated pipe 20 viewed from the outside in the D direction. As part of the corrugated pipe 20, an inner wall 24A is indicated by an imaginary line (chain double-dashed line). As a part of the corrugated member 32, a portion extending in an oblique direction crossing the Z direction is indicated by a solid line. Further, with respect to the corrugated member 32, the outer end face 33A is indicated by a solid line, and the inner end face 34A is indicated by a broken line.

Let point A, point B, point C, and point D be points of intersection of the outline of the inner wall 24A and the outline of the outer end face 33A when viewed from the outside in the D direction. The points A and B are spaced apart in a direction orthogonal to the Z direction (referred to as the Y direction). Points C and D are spaced apart in the Y direction. A quadrangle ABCD connecting points A, B, C, and D is a parallelogram. The area of this parallelogram is called a second contact area SB.

On the other hand, point E, point F, point G, and point H are points of intersection of the outline of the inner wall 24A and the outline of the inner end surface 34A. The points E and F are arranged on the straight line connecting the points A and B and are spaced apart in the Y direction between the points A and B. The points G and H are arranged on the straight line connecting the points C and D and are spaced apart in the Y direction between the points C and D. A quadrangle EFGH connecting points E, F, G, and H is a parallelogram. The area of this parallelogram is called 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 made smaller than the second contact area SB between the holding portion 30 and the corrugated pipe 20 .

<Manufacture of composite pipe>
As a method of manufacturing the composite pipe 10 shown in FIG. 5, for example, the following method is conceivable. Specifically, four corrugated members 32 are supplied to the outer peripheral surface 13 of the inner tube 12 fed in the Z direction so that they are spaced apart in the circumferential direction and are linear in the Z direction. Immediately after the four corrugated members 32 are supplied, a molten resin material (a melt of a resin composition for forming the corrugated pipe 20) is extruded cylindrically from a die (not shown) to form the inner pipe 12 and the four corrugated members. The member 32 is covered with the resin material.

After the inner tube 12, the four corrugated members 32 and the cylindrical resin material are assembled, a step of forming the resin material into a bellows shape is performed using a corrugated die located downstream of the die. The corrugated pipe 20 is formed by forming the resin material into a bellows shape. After the corrugating process is performed in the corrugating mold, each member is cooled in a cooling bath (not shown). Thus, the composite pipe 10 having the inner pipe 12, the holding portion 30, and the corrugated pipe 20 is manufactured. In addition, since the corrugated pipe 20 is sucked in the corrugated mold, a gap is formed between the crests 22 and the corrugated member 32 . On the other hand, a portion of the trough 24 and the corrugated member 32 are in contact.

[Action and effect]
Next, the action 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), the corrugated pipe 20 and the holding portion 30 must be shortened in the Z direction to expose the end of the inner pipe 12. At the end of the composite pipe 10 in the Z direction, for example, 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 tube 12 is held inside the corrugated tube 20 by a holding portion 30 .

By moving the Z-direction end (the left end in the drawing) of the corrugated pipe 20 shown in FIG. The crests 22 adjacent to each other in the direction are deformed 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), thereby shortening in the Z direction. That is, since the corrugated tube 20 and the holding portion 30 are shortened in the Z direction, the end of the inner tube 12 in the Z direction is exposed.

Thus, according to the composite pipe 10 , the inner pipe 12 can be held inside the corrugated pipe 20 by holding the inner pipe 12 with the holding portion 30 . Furthermore, 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 direction of expansion and contraction of the corrugated pipe 20 is aligned with the direction of elastic deformation of the corrugated member 32 , the expansion and contraction of the corrugated pipe 20 is applied to the holding portion 30 . less likely to be hindered by That is, in the composite pipe 10 holding 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 reduced by the frictional resistance between the holding portion 30 and the inner pipe 12. It becomes 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. It becomes easy to transform and integrally. Furthermore, 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 . It becomes easier to move relative to 12. These actions make it easier to move the corrugated tube 20 relative to the inner tube 12 .

Furthermore, 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 The frictional resistance between the portion 30 and the corrugated pipe 20 may be smaller than that. As a result, there is a possibility that the frictional resistance acting on the contact portion between the holding portion 30 and the inner tube 12 will be reduced, making it difficult for the holding portion 30 to stay on the outer peripheral surface 13 of the inner pipe 12. 30 can be made easier to move relative to inner tube 12 .

Further, according to the composite pipe 10, the shape of the corrugated member 32 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 30 can be easily deformed integrally. Furthermore, 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 number of places where the corrugated members 32 hold the inner pipe 12 is reduced compared to a configuration in which only one corrugated member 32 is provided. , the holding state of the inner tube 12 can be stabilized. That is, it is possible to prevent the expansion and contraction of the corrugated pipe 20 from being hindered, and to stabilize the holding state of the inner pipe 12 .

Furthermore, according to the composite pipe 10, the corrugated pipe 20 is configured to repeat the crests 22 and the troughs 24 in the Z direction. to deform the corrugated pipe 20 in the Z direction. Thereby, the corrugated pipe 20 can be easily expanded and contracted in the Z direction.

[Second embodiment]
As an example of the present disclosure, a composite pipe 40 according to a second embodiment will be described. In addition, about the structure similar to the composite pipe 10 of 1st Embodiment, the same code|symbol as the composite pipe 10 is provided, and description is abbreviate|omitted.

A composite tube 40 shown in FIG. 7 has an inner tube 12 , a corrugated tube 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 separately from the inner tube 12 and the corrugated tube 20 . Moreover, the holding part 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 tube 12 . In addition, 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 peaks 22 and the valleys 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 . Thereby, the spiral member 52 holds the inner tube 12 inside the corrugated tube 20 .

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

Furthermore, the spiral member 52 is formed in the shape of a coil spring. That is, the spiral member 52 is formed 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 pipe 20 expands and contracts in the Z direction. In addition, the helical member 52 is formed in a tubular shape having a rectangular portion 33 and a semi-circular portion 34, similar to the corrugated member 32 (see FIG. 3). An outer end surface 33A of the rectangular portion 33 is in contact with a portion of the inner surface 25. As shown in FIG. An inner end surface 34A of the semicircular portion 34 is in contact with a portion of the outer peripheral surface 13 . Note that the helical member 52 may be disposed in the composite pipe 40 by inserting a preformed one between the inner pipe 12 and the corrugated pipe 20 , or may be disposed between the inner pipe 12 and the corrugated pipe 20 . It may be positioned within the composite tube 40 by being formed therebetween.

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 tube 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 slides relatively easily 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.

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

[Action and effect]
Next, the action and effect of the composite pipe 40 according to the second embodiment will be described. It should be noted that descriptions of the same functions as those of the first embodiment may be omitted.

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

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

Thus, according to the composite pipe 40 , the inner pipe 12 can be held inside the corrugated pipe 20 by holding the inner pipe 12 with the holding portion 50 . Furthermore, 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 part 50 has the linear helical member 52 and the direction of expansion and contraction of the corrugated pipe 20 is aligned with the direction of elastic deformation of the helical member 52 , the expansion and contraction of the corrugated pipe 20 is applied to the holding part 50 . less likely to be hindered 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 . .

In addition, according to the composite tube 40, when the holding section 50 is elastically deformed in the Z direction, the frictional resistance acting on the contact portion between the holding section 50 and the corrugated tube 20 increases the frictional resistance between the holding section 50 and the inner tube 12. It becomes 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. It becomes easy to deform the and integrally. Furthermore, 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 . It becomes easier to move relative to 12. These actions make it easier to move the corrugated tube 20 relative to the inner tube 12 .

Furthermore, according to the composite pipe 40, 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 50 and the outer peripheral surface 13 is The frictional resistance between the portion 30 and the corrugated pipe 20 may be smaller than that. As a result, there is a possibility that the frictional resistance acting on the contact portion between the holding portion 50 and the inner tube 12 will be reduced, making it difficult for the holding portion 50 to stay on the outer peripheral surface 13 of the inner pipe 12. 50 can be made easier to move relative to inner tube 12 .

Further, according to the composite pipe 40, the shape of the helical member 52 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 50 can be easily deformed integrally. Furthermore, since it is possible to hold the inner tube 12 with only one spiral member 52, the number of parts of the holding portion 50 can be reduced. That is, it is possible to prevent 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, a composite pipe 60 according to a third embodiment will be described. In addition, about the structure similar to the composite pipe 10 of 1st Embodiment, the same code|symbol as the composite pipe 10 is provided, and description is abbreviate|omitted.

A composite tube 60 shown in FIG. 9 has an inner tube 12 , a corrugated tube 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 separately from the inner tube 12 and the corrugated tube 20 . Moreover, the holding part 70 has one mesh member 72 as an example.

The mesh 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 . In addition, since the net-like member 72 is a member that contacts a part of the outer peripheral surface 13 of the inner tube 12 and a part of the inner surface 25 of the corrugated tube 20, the mesh member 72 is "planar (entirely) with the outer peripheral surface 13 and the inner surface 25. It is not the "contacted" member. Here, the mesh member 72 includes at least one of straight lines and curved lines. In other words, in the present disclosure, the "net-like member" is a concept included in the "linear member".

Specifically, the mesh member 72 covers the outer peripheral surface 13 of the inner tube 12 in the circumferential direction. The mesh member 72 is sandwiched between the inner pipe 12 and the corrugated pipe 20 in the D direction of the inner pipe 12 . Thereby, the mesh member 72 holds the inner tube 12 inside the corrugated tube 20 . Further, the mesh member 72 is made of elastomer. Examples of elastomers 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 shape in which a plurality of wavy vertices having amplitudes in the cross direction crossing the Z-axis direction are joined when viewed in the D direction. As an example, the net-like member 72 is formed in a mesh shape by arranging a plurality of corrugated members 32 (see FIG. 1) adjacent to each other in the circumferential direction of the inner tube 12 and joining the vertices of the corrugated members 32 in the circumferential direction. It is That is, the mesh member 72 is formed to be elastically deformable in the Z direction. The mesh member 72 is configured to be elastically deformed in the Z direction as the corrugated pipe 20 expands and contracts in the Z direction.

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

The frictional resistance between the holding portion 70 and the outer peripheral surface 13 is made smaller than the frictional resistance between the holding portion 70 and the inner surface 25 of the corrugated tube 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 slides relatively easily 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.

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

[Action and effect]
Next, the action and effect of the composite pipe 60 according to the third embodiment will be described. It should be noted that descriptions of the same functions as those of the first embodiment may be omitted.

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

The corrugated tube 20 is shortened in the Z direction by moving the Z-direction end (the left end in the drawing) of the corrugated tube 20 shown in FIG. 10 to one side in the Z direction (the right side in the drawing). In this case, the holding portion 70 (one mesh member 72) is elastically deformed as the corrugated pipe 20 expands and contracts (shortens), thereby shortening in the Z direction. That is, since the corrugated tube 20 and the holding portion 70 are shortened in the Z direction, the end of the inner tube 12 in the Z direction is exposed.

Thus, according to the composite pipe 60 , the inner pipe 12 can be held inside the corrugated pipe 20 by holding the inner pipe 12 with the holding portion 70 . Furthermore, 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 part 70 has the linear mesh member 72 and the elastic deformation direction of the corrugated pipe 20 is aligned with the elastic deformation direction of the corrugated pipe 20 , the expansion and contraction of the corrugated pipe 20 will cause the holding part 70 to less likely to be hindered 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 . .

In addition, 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 increases the frictional resistance between the holding portion 70 and the inner pipe 12. It becomes 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. It becomes easy to deform the and integrally. Furthermore, 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 . It becomes easier to move relative to 12. These actions make it easier to move the corrugated tube 20 relative to the inner tube 12 .

Furthermore, according to the composite pipe 60, 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 70 and the outer peripheral surface 13 is There is a possibility that the frictional resistance between the portion 70 and the corrugated pipe 20 will be smaller. As a result, there is a possibility that the frictional resistance acting on the contact portion between the holding portion 70 and the inner pipe 12 will be reduced, making it difficult for the holding portion 70 to stay on the outer peripheral surface 13 of the inner pipe 12. Therefore, the corrugated pipe 20 and the holding portion 70 can be made easier to move relative to 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. Furthermore, since the mesh member 72 covers the outer peripheral surface 13 of the inner tube 12 in the circumferential direction, when the corrugated tube 20 is rotated (twisted) around the central axis, the outer peripheral surface 13 of the inner tube 12 and The portion in contact with the mesh member 72 is prevented from becoming biased toward a part of the inner tube 12 in the circumferential direction. In other words, it is possible to prevent the expansion and contraction of the corrugated pipe 20 from being hindered, and to restrain the bias of the holding portion 70 when the corrugated pipe 20 is twisted.

In addition, this invention is not limited to said embodiment.

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

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

<Second modification>
FIG. 12 shows a section of a corrugated member 92 as a second variant. The wave member 92 is formed as a solid member as an example of a linear member. Further, the shape of the wave member 92 is a shape in which the trapezoidal portion 94 and the semicircular portion 34 are integrated when viewed from the central axis direction of the wave member 92 . A cross section perpendicular to the central axis of the wave 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. An outer end surface 94A (a surface corresponding to the bottom 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 part of the inner surface 25 . The inner end surface 34A is in contact with a portion of the outer peripheral surface 13 . Thus, by having the trapezoidal portion 94, the contact area on the inner surface 25 side is increased compared to the rectangular portion 33 (see FIG. 3), so that the corrugated member 92 can be moved more easily as the corrugated pipe 20 is moved. can do. In addition, in FIG. 12, hatching is omitted in order to show the cross-sectional shape of the wave member 92 in an easy-to-understand manner.

<Other Modifications>
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 . Also, the first contact area SA may be equal to 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 . Also, the first contact area SA may be equal to or smaller than the second contact area SB. Furthermore, an outer tube 82 may be used instead of the corrugated tube 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 . Also, the first contact area SA may be equal to or smaller than the second contact area SB. Furthermore, an outer tube 82 may be used instead of the corrugated tube 20 .

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

The cross-sectional shape of the corrugated pipe 20 is not limited to a rectangular wave shape, and may be, for example, a triangular wave shape.

The coating layer may have a tubular portion that covers the tubular body, and a helical 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 in the Z direction and are spaced apart in the Z direction.

The composite pipe according to each embodiment and each modification of the present invention has been described above. Of course, it can be implemented in various ways.

DESCRIPTION OF SYMBOLS 10... Composite tube, 12... Inner tube (an example of tubular body), 13... Outer peripheral surface, 20... Corrugated tube (an example of coating layer), 22... Mountain portion, 24... Valley portion, 30... Holding portion, 32... Waveform Member (an example of linear member) 40 Composite tube 50 Holding part 52 Spiral member (an example of linear member) 60 Composite tube 70 Holding part 72 Reticulated member (of linear member Example), 80... Composite tube, 82... Outer tube (an example of a coating layer), 92... Waveform member (an example of a linear member), SA... First contact area, SB... Second contact area

Claims (10)

a tubular body;
a coating layer formed in a tubular shape, covering the outer peripheral surface of the tubular body, and capable of expanding and contracting in the axial direction of the tubular body;
A linear member disposed between the tubular body and the covering layer in a state in which relative movement between the tubular body and the covering layer is permitted , and elastically deformed in the axial direction as the covering layer expands and contracts. and holding the tubular body inside the covering layer;
has
The linear member is a wavy member formed in a wavy shape having an amplitude in a crossing direction that intersects the axial direction, and the linear member is not arranged on the outer peripheral surface over the entire area in the axial direction. A plurality are arranged at intervals in the circumferential direction of the tubular body so that an arrangement area is set,
composite tube. The width of the portion of the linear member in contact with the tubular body in a cross section orthogonal to the central axis of the linear member is set to a length shorter than the width of the portion of the linear member in contact with the coating layer.
The composite tube of Claim 1. The composite pipe according to claim 1, wherein frictional resistance between said holding portion and said outer peripheral surface is smaller than frictional resistance between said holding portion and said coating layer. The composite pipe according to claim 3 , wherein a first contact area between said retaining portion and said outer peripheral surface is smaller than a second contact area between said retaining portion and said coating layer. a tubular body;
a coating layer formed in a tubular shape, covering the outer peripheral surface of the tubular body, and capable of expanding and contracting in the axial direction of the tubular body;
a linear member disposed between the tubular body and the covering layer, elastically deformed in the axial direction as the covering layer expands and contracts, and holding the tubular body inside the covering layer; a holding part;
has
The width of the portion of the linear member in contact with the tubular body in a cross section orthogonal to the central axis of the linear member is set to a length shorter than the width of the portion of the linear member in contact with the coating layer.
composite tube. The linear member has a rectangular portion that constitutes a portion on the coating layer side in the cross section and has a rectangular shape when viewed from the axial direction, and a portion on the tubular body side in the cross section that is continuous with the rectangular portion. and a semicircular portion that is configured and convex toward the tubular body when viewed from the axial direction,
A composite tube according to claim 5. 5 or claim 1, wherein the linear members are a plurality of wavy members arranged at intervals in the circumferential direction of the tubular body and formed into a wavy shape having amplitude in an intersecting direction intersecting with the axial direction. 7. Composite tube according to 6 . The composite tube according to claim 5 or 6 , wherein the linear member is a spiral member spirally wound around the outer peripheral surface of the tubular body. 7. The linear member is a net-like member formed in a net shape by connecting a plurality of vertexes of waveforms having amplitude in a direction intersecting with the axial direction and covering the outer peripheral surface in the circumferential direction . A composite tube as described in . The composite pipe according to any one of claims 1 to 9 , wherein the coating layer is a corrugated pipe in which peaks and valleys are repeated in the axial direction.

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