Composite pipe

Abstract

To restrain noise caused by collision of a shell and a corrugated tube, and easily perform an operation for inserting the shell into the corrugated tube.SOLUTION: A composite tube 10 comprises a shell 11, and a corrugated tube 12 covering an outer periphery of the shell 11. The corrugated tube 12 has plural protrusions 23 projecting radially inward of the corrugated pipe 12 while crest parts 21 and trough parts 22 having an outside diameter smaller than that of the crest part 21 are alternately provided in an axial line direction of the corrugated pipe 12 in a bellows-like manner. The plural protrusions 23 are provided at unequal intervals in a circumferential direction of the corrugated pipe 12.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a composite pipe. [Background technology]

[0002] BACKGROUND ART Conventionally, there is a composite pipe that includes a pipe body and a corrugated pipe that covers the outer periphery of the pipe body (see, for example, Patent Document 1). The corrugated pipe has a bellows shape in which peaks and valleys are alternately provided in the axial direction.

[0003] The tube is made of a resin material such as cross-linked polyethylene. The corrugated pipe has a base pipe and a coating layer that covers the outer surface of the base pipe. The base pipe is made of a resin material such as closed-cell foamed polyethylene. The coating layer is made of a resin material such as polyethylene.

[0004] The pipe body and the corrugated pipe are formed separately, and then the composite pipe is formed by inserting the pipe body into the corrugated pipe. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-26129 Summary of the Invention [Problem to be solved by the invention]

[0006] When a composite pipe is used for water piping, the pressure inside the pipe may suddenly change when the faucet is turned off. At this time, the impact force acting on the pipe causes it to collide with the corrugated pipe, generating noise.

[0007] To address this issue, it is conceivable to reduce the inner diameter of the roots of the corrugated pipe and to reduce the gap between the pipe body and the corrugated pipe, thereby preventing collisions between the pipe body and the corrugated pipe. However, in this case, the pipe body is more likely to interfere with the corrugated pipe when it is inserted into the corrugated pipe, which reduces workability. [Means for solving the problem]

[0008] A composite pipe for solving the above problem comprises a pipe body and a corrugated pipe covering the outer periphery of the pipe body, wherein the corrugated pipe has a bellows shape in which peaks and valleys having an outer diameter smaller than the outer diameter of the peaks are alternately arranged in the axial direction of the corrugated pipe, and the corrugated pipe has a plurality of protrusions that protrude radially inward of the corrugated pipe, and the plurality of protrusions are arranged at uneven intervals in the circumferential direction of the corrugated pipe.

[0009] According to this configuration, the multiple protrusions protruding from the corrugated pipe partially reduce the gap between the corrugated pipe and the pipe body in the circumferential direction. This limits the relative displacement of the pipe body with respect to the corrugated pipe. Therefore, when an impact force acts on the pipe body due to a sudden change in pressure of the fluid flowing inside the pipe body, a collision between the pipe body and the corrugated pipe can be suppressed. This reduces the generation of noise caused by a collision between the pipe body and the corrugated pipe.

[0010] On the other hand, with the above configuration, the gap between the valley portions and the pipe body is less likely to interfere with each other when inserting the pipe into the corrugated pipe, compared to when the gap between the valley portions and the pipe body is reduced over the entire circumferential direction of the corrugated pipe by, for example, reducing the inner diameter of the valley portions. This makes it easier to insert the pipe into the corrugated pipe. [Effects of the Invention]

[0011] According to the present invention, it is possible to suppress the generation of noise caused by a collision between a pipe body and a corrugated pipe, and to easily perform the work of inserting a pipe body into a corrugated pipe. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a perspective view of a composite pipe according to a first embodiment. [Figure 2] FIG. 2 is a half cross-sectional view taken along line 2-2 in FIG. [Figure 3] Cross-sectional view taken along line 3-3 in Figure 2. [Figure 4] FIG. [Figure 5] FIG. 5 is an enlarged cross-sectional view taken along line 5-5 in FIG. 3. [Figure 6] FIG. 10 is a perspective view of a composite pipe according to a second embodiment. [Figure 7] FIG. [Figure 8] 8A is a cross-sectional view taken along line 8a-8a in FIG. 7, and FIG. 8B is a cross-sectional view taken along line 8b-8b in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] First Embodiment The first embodiment will be described below with reference to FIGS. First, the configuration of the composite pipe 10 will be described.

[0014] As shown in FIGS. 1 to 3, a composite pipe 10 includes a pipe body 11 and a corrugated pipe 12 that covers the outer periphery of the pipe body 11. The tube body 11 is made of a resin material.

[0015] Examples of resin materials constituting the tubular body 11 include polyolefins such as polybutene, polyethylene, cross-linked polyethylene, and polypropylene, as well as vinyl chloride. Only one of the above resin materials may be used, or two or more may be used in combination. The resin material constituting the tubular body 11 may also contain other additives. The tubular body 11 of this embodiment is made of cross-linked polyethylene.

[0016] 1 to 5, the corrugated pipe 12 has a bellows shape in which peaks 21 and valleys 22 having an outer diameter smaller than that of the peaks 21 are alternately provided in the axial direction of the corrugated pipe 12. The inner and outer diameters of the valleys 22 are smaller than the inner diameter of the peaks 21.

[0017] 1 and 3 to 5, the corrugated pipe 12 has a plurality of (six in this embodiment) protrusions 23 that protrude radially inward of the corrugated pipe 12. The protrusions 23 are provided in the valley portions 22.

[0018] 3, the multiple protrusions 23 are provided at intervals from one another in the circumferential direction of the corrugated pipe 12. The multiple protrusions 23 are provided at equal intervals (60° intervals in this embodiment) in the circumferential direction.

[0019] The protrusion 23 is tapered. More specifically, the protrusion 23 has a pair of inclined surfaces 23a that are inclined radially inward as they approach the center of the protrusion 23 in the circumferential direction, and has a V-shaped cross section.

[0020] In this embodiment, all the valleys 22 are provided with protrusions 23 . The corrugated pipe 12 has a base pipe made of a resin material and a coating layer (both not shown) made of a resin material that coats the outer circumferential surface of the base pipe. The coating layer is in close contact with the outer circumferential surface of the base pipe.

[0021] Examples of resin materials that can be used to form the base pipe include polyurethane, polystyrene, polyethylene, polypropylene, and ethylene propylene diene rubber, as well as mixtures thereof. The resin materials may contain other additives. The base pipe is preferably a foam. The base pipe of this embodiment is made of closed-cell foamed polyethylene.

[0022] Examples of resin materials constituting the coating layer include polyolefins such as polybutene, polyethylene, cross-linked polyethylene, and polypropylene, as well as vinyl chloride. Only one of the above resin materials may be used, or two or more may be used in combination. The resin material constituting the coating layer may also contain other additives. The coating layer of this embodiment is made of polyethylene.

[0023] Next, the effects of this embodiment will be described. (1) The corrugated pipe 12 has a plurality of protrusions 23 that protrude radially inward of the corrugated pipe 12. The protrusions 23 are provided at intervals from one another in the circumferential direction of the corrugated pipe 12.

[0024] With this configuration, the gap between the corrugated pipe 12 and the pipe body 11 is partially reduced in the circumferential direction by the multiple protrusions 23 protruding from the corrugated pipe 12. This restricts the relative displacement of the pipe body 11 with respect to the corrugated pipe 12. Therefore, when an impact force acts on the pipe body 11 due to a sudden change in pressure of the fluid flowing inside the pipe body 11, it is possible to suppress a collision between the pipe body 11 and the corrugated pipe 12. This makes it possible to suppress the generation of noise caused by a collision between the pipe body 11 and the corrugated pipe 12.

[0025] On the other hand, with the above configuration, the tube body 11 is less likely to interfere with the valley portions 22 when inserting the corrugated pipe 12, compared to when the gap between the valley portions 22 and the tube body 11 is reduced over the entire circumferential direction of the corrugated pipe 12 by reducing the inner diameter of the valley portions 22, for example. This makes it easier to insert the tube body 11 into the corrugated pipe 12.

[0026] Therefore, it is possible to suppress the generation of noise caused by the collision between the pipe body 11 and the corrugated pipe 12, and also to facilitate the work of inserting the pipe body 11 into the corrugated pipe 12. (2) Since the protrusions 23 are provided in the valley portions 22, which have an inner diameter smaller than the inner diameter of the peak portions 21, the size of the protrusions 23 is smaller than when the protrusions 23 are provided in the peak portions 21. Therefore, the weight of the corrugated pipe 12 is prevented from increasing by providing the protrusions 23.

[0027] Furthermore, with the above configuration, the provision of the projections 23 can prevent the corrugated tube 12 from becoming less susceptible to bending and deformation. (3) The protrusion 23 is tapered.

[0028] With this configuration, the tip of the protrusion 23 is small, which makes it even less likely that the corrugated pipe 12 and the tubular body 11 will interfere with each other when they are inserted into each other. This makes it even easier to insert the tubular body 11 into the corrugated pipe 12.

[0029] Second Embodiment The second embodiment will be described below with reference to FIGS. 6 to 8, focusing on the differences from the first embodiment.

[0030] As shown in FIGS. 6 to 8, the valleys 22 of the corrugated pipe 12 have a first valley 22A and a second valley 22B that is provided at a position different from the first valley 22A in the axial direction. As shown in FIGS. 8(a) and 8(b), the first valley portion 22A has a first inner diameter R1. The second valley portion 22B has a second inner diameter R2 that is larger than the first inner diameter R1 (R1 <R2)。

[0031] As shown in FIG. 7, a plurality of second valley portions 22B are provided between two first valley portions 22A that are adjacent to each other in the axial direction. Next, the effects of this embodiment will be described.

[0032] (4) The valley portion 22 has a first valley portion 22A and a second valley portion 22B that is provided at a different position in the axial direction from the first valley portion 22A. The first valley portion 22A has a first inner diameter R1. The second valley portion 22B has a second inner diameter R2 that is larger than the first inner diameter R1.

[0033] With this configuration, the gap between the corrugated pipe 12 and the pipe body 11 is smaller in the first valley portions 22A of the corrugated pipe 12 than in the second valley portions 22B. As a result, the relative displacement of the pipe body 11 with respect to the corrugated pipe 12 is more restricted than in a case where all valley portions 22 are formed by the second valley portions 22B. Therefore, when an impact force acts on the pipe body 11 due to a sudden change in pressure of the fluid flowing inside the pipe body 11, a collision between the pipe body 11 and the corrugated pipe 12 can be suppressed. As a result, the generation of noise due to a collision between the pipe body 11 and the corrugated pipe 12 can be suppressed.

[0034] On the other hand, with the above configuration, compared to a case where all of the valley portions 22 are configured as the first valley portions 22A, thereby reducing the gap between all of the valley portions 22 and the pipe 11, interference between the two is less likely to occur when inserting the corrugated pipe 12 into the pipe 11. This makes it easier to insert the pipe 11 into the corrugated pipe 12.

[0035] (5) A plurality of second valley portions 22B are provided between two first valley portions 22A that are adjacent to each other in the axial direction. With this configuration, compared to when the first valley portions 22A and the second valley portions 22B are alternately provided in the axial direction, interference between the corrugated pipe 12 and the pipe body 11 is less likely to occur when the corrugated pipe 12 is inserted. This makes it easier to insert the pipe body 11 into the corrugated pipe 12.

[0036] <Example of change> The above embodiment can be modified as follows: The present embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0037] In the first embodiment, some of the valleys 22 may not have the protrusions 23 . In the first embodiment, the number of protrusions 23 provided in one valley portion 22 may be changed as appropriate.

[0038] In the first embodiment, the plurality of protrusions 23 may be provided at uneven intervals in the circumferential direction. In the first embodiment, the protrusion 23 does not have to be tapered.

[0039] In the first embodiment, the protrusions 23 may be provided on the peaks 21. In the second embodiment, the number of second valley portions 22B provided between two first valley portions 22A adjacent to each other in the axial direction can be changed as appropriate. For example, the first valley portions 22A and the second valley portions 22B may be provided alternately in the axial direction.

[0040] In the first and second embodiments, the corrugated pipe 12 may not have a coating layer, that is, may be formed only from a base pipe. In the first and second embodiments, the base pipe of the corrugated pipe 12 does not have to be made of a foam. For example, the corrugated pipe 12 may be made of a soft resin material.

[0041] <Additional Notes> The technical concept that can be understood from the above embodiment will be described. (1) a tube body; a corrugated pipe covering the outer periphery of the pipe body, the corrugated pipe has a bellows shape in which peaks and valleys having an outer diameter smaller than the outer diameter of the peaks are alternately arranged in the axial direction of the corrugated pipe, and has a plurality of protrusions protruding radially inward of the corrugated pipe, The plurality of protrusions are provided at intervals from one another in the circumferential direction of the corrugated pipe. Composite tube.

[0042] According to this configuration, the multiple protrusions protruding from the corrugated pipe partially reduce the gap between the corrugated pipe and the pipe body in the circumferential direction. This limits the relative displacement of the pipe body with respect to the corrugated pipe. Therefore, when an impact force acts on the pipe body due to a sudden change in pressure of the fluid flowing inside the pipe body, a collision between the pipe body and the corrugated pipe can be suppressed. This reduces the generation of noise caused by a collision between the pipe body and the corrugated pipe.

[0043] On the other hand, with the above configuration, the gap between the valley portions and the pipe body is less likely to interfere with each other when inserting the pipe into the corrugated pipe, compared to when the gap between the valley portions and the pipe body is reduced over the entire circumferential direction of the corrugated pipe by, for example, reducing the inner diameter of the valley portions. This makes it easier to insert the pipe into the corrugated pipe.

[0044] (2) The root portion has an inner diameter smaller than the inner diameter of the peak portion, The protrusion is provided in the valley portion. The composite pipe according to the technical idea (1).

[0045] According to this configuration, since the protrusions are provided in the valley portions, the size of the protrusions is smaller than when the protrusions are provided in the peak portions, and therefore, the weight of the corrugated pipe is prevented from increasing due to the provision of the protrusions. Furthermore, with the above configuration, it is possible to prevent the corrugated pipe from becoming less susceptible to bending deformation due to the provision of the protrusions.

[0046] (3) The protrusion is tapered. The composite pipe according to the technical idea (1) or the technical idea (2).

[0047] With this configuration, the tip of the protrusion is small, which makes it even less likely for the pipe body to interfere with the corrugated pipe when inserting it, making it even easier to insert the pipe body into the corrugated pipe.

[0048] (4) a tube body; a corrugated pipe covering the outer periphery of the pipe body, the corrugated pipe has a bellows shape in which peaks and valleys having an outer diameter smaller than the outer diameter of the peaks are alternately provided in the axial direction of the corrugated pipe, the valley portion has a first valley portion and a second valley portion provided at a position different from the first valley portion in the axial direction, the first valley portion has a first inner diameter; The second valley portion has a second inner diameter that is larger than the first inner diameter. Composite tube.

[0049] According to this configuration, the gap between the corrugated pipe and the pipe body is smaller in the first valley portions of the corrugated pipe than in the second valley portions. This restricts the relative displacement of the pipe body with respect to the corrugated pipe compared to when all valley portions are formed by the second valley portions. This makes it possible to suppress a collision between the pipe body and the corrugated pipe when an impact force acts on the pipe body due to a sudden change in pressure of the fluid flowing inside the pipe. This makes it possible to suppress the generation of noise caused by a collision between the pipe body and the corrugated pipe.

[0050] On the other hand, with the above configuration, compared to a case where all the valleys are configured as first valleys, thereby reducing the gap between all the valleys and the pipe, interference between the two is less likely to occur when inserting the pipe into the corrugated pipe, making it easier to insert the pipe into the corrugated pipe.

[0051] (5) A plurality of the second valley portions are provided between two of the first valley portions that are adjacent to each other in the axial direction. The composite pipe according to the technical idea (4).

[0052] With this configuration, compared to when the first and second valleys are alternately arranged in the axial direction, the two are less likely to interfere with each other when inserting the pipe into the corrugated pipe, making it easier to insert the pipe into the corrugated pipe. [Explanation of symbols]

[0053] 10…Composite pipe 11...Body 12...Corrugated pipe 21...Yamabe 22... Valley 22A...First valley 22B…Second Valley 23…Protrusion 23a…Slope surface

Claims

[Claim 1] A tube body, a corrugated pipe covering the outer periphery of the pipe body, the corrugated pipe has a bellows shape in which peaks and valleys having an outer diameter smaller than the outer diameter of the peaks are alternately arranged in the axial direction of the corrugated pipe, and has a plurality of protrusions protruding radially inward of the corrugated pipe, the plurality of protrusions partially reduce the gap between the corrugated pipe and the pipe body in both the circumferential direction and the axial direction, The plurality of protrusions are provided at uneven intervals in the circumferential direction of the corrugated pipe. Composite tube.

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