Pipe with sheath tube

Abstract

To provide a pipe with a sheath tube.SOLUTION: A pipe with a sheath tube 21 comprises a sheath tube 23 and a pipe body 22. A pipe joint 11 comprises a holding ring 15 that bites into an outer peripheral surface of the pipe body 22 exposed from the sheath tube 23 to prevent the pipe body 22 from coming off of the pipe joint 11. An outer diameter of a bottom 26a of a recess part 26 in the sheath tube 23 is smaller than the maximum inner diameter on an opening side of a pipe insertion port 16a of the pipe joint 11, and larger than the minimum inner diameter on a back side of the pipe insertion port 16a.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a pipe with a sheath tube used for supplying hot and cold water or the like. [Background technology]

[0002] Patent Document 1 discloses a corrugated pipe into which a flexible pipe for supplying hot and cold water is inserted. Patent Document 2 discloses a resin pipe on which circumferential lines serving as markers for insertion into a pipe joint are drawn at equal intervals in the direction of extension of the axis. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-26129 A [Patent Document 2] JP 2000-88154 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a novel pipe with a sheath tube. [Means for solving the problem]

[0005] In order to achieve the above-mentioned object, the pipe with sheath tube of the invention of claim 1 is a pipe with a sheath tube comprising a sheath tube having an accordion-like shape in which convex portions and concave portions are alternately arranged in the extension direction of an axis and being expandable and contractible in the extension direction, and a pipe body inserted into the sheath tube, wherein the pipe fitting is provided with a retaining ring that bites into the outer peripheral surface of the pipe body exposed from the sheath tube to prevent the pipe body from slipping out of the pipe fitting, and the outer diameter of the bottom of the concave portion of the sheath tube is smaller than the maximum inner diameter on the opening side of the pipe insertion port of the pipe fitting and larger than the minimum inner diameter on the rear side of the pipe insertion port. [Brief description of the drawings]

[0006] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] FIG. [Diagram 5] FIG. 4 is a longitudinal sectional view of the pipe joint with a sheath pipe inserted therein; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Hereinafter, one embodiment of the present invention will be described. First, a pipe joint to which a sheath pipe is connected will be described.

[0008] As shown in Fig. 4, a through hole 12a is formed in a joint body 12 constituting a pipe joint 11. A step portion 12b is formed on the inner peripheral surface of one end side (left end side in the drawing) of the through hole 12a. A flange portion 13a of an inner tube 13 inserted into the through hole 12a from the other end side (right end side in the drawing) abuts against the step portion 12b. A plurality of annular grooves 12c are formed on the inner peripheral surface of the through hole 12a. A seal ring 14 is housed in each of the annular grooves 12c.

[0009] A step 12d is formed on the inner peripheral surface of the other end side of the through hole 12a. A retaining ring 15 having retaining claws 15a is engaged with the step 12d. A female thread 12e is formed on the inner peripheral surface of the other end side of the through hole 12a. A fastening ring 16 is screwed into the female thread 12e. The step 12d and the fastening ring 16 hold the outer peripheral edge of the retaining ring 15 in a predetermined position. An insertion space 17 is formed between the outer peripheral surface of the inner tube 13 and the inner peripheral surfaces of the joint body 12 and the fastening ring 16.

[0010] 5, the pipe body 22 of the sheath pipe 21 is disposed in the insertion space 17 of the pipe fitting 11, thereby connecting the pipe fitting 11 to the pipe body 22. When the pipe fitting 11 and the pipe body 22 are connected, the retaining claws 15a of the retaining ring 15 bite into the outer circumferential surface of the pipe body 22, preventing the pipe body 22 from coming out of the pipe fitting 11.

[0011] In addition, "L" in the drawing indicates the appropriate insertion depth of the pipe body 22 in the insertion space 17. "M" in the drawing indicates the maximum inner diameter of the opening (pipe insertion port) 16a of the fastening ring 16 located on the insertion side of the pipe body 22 (the right end side in the drawing).

[0012] Next, the sheath pipe 21 will be described. As shown in Fig. 1, a pipe with a sheath pipe 21 comprises a pipe body 22 and a sheath pipe 23 into which the pipe body 22 is loosely inserted. The pipe body 22 and the sheath pipe 23 have central axes S that are approximately aligned. The sheath pipe 23 protects the pipe body 22 from being stepped on during construction, ensures the weather resistance of the pipe body 22, and is also used in a sheath pipe construction method to facilitate replacement of the pipe body 22 in the future.

[0013] As shown in Fig. 2, the pipe body 22 is made of synthetic resin such as cross-linked polyethylene or polybutene, and is formed into a flexible circular tube. A plurality of insertion marks 22a are printed on the outer circumferential surface of the pipe body 22 at equal intervals in the extension direction of the axis S (left-right direction in the drawing). "K" in the drawing indicates the interval (size). The interval K of the insertion marks 22a is the same as the insertion depth L of the pipe body 22 into the pipe fitting 11 (see Fig. 5).

[0014] 3, the sheath pipe 23 is made of synthetic resin such as polypropylene, polyethylene, polyamide, etc., and is formed into a flexible circular tube. The sheath pipe 23 is colorless and transparent or colored and transparent. Examples of colored and transparent include blue transparent for use in water paths of cold and hot water supply piping, red transparent for use in hot water paths, and white transparent for versatility.

[0015] The sleeve pipe 23 has a bellows shape in which annular convex portions 25 and annular concave portions 26 are alternately arranged in the extension direction of the axis S. In other words, the sleeve pipe 23 can be said to be a corrugated pipe that is expandable and contractable in the extension direction of the axis S.

[0016] The tip 25a of the protrusion 25 is the portion where the inner and outer diameters are maximum in the sleeve tube 23. The bottom 26a of the recess 26 is the portion where the inner and outer diameters are minimum in the sleeve tube 23. The thickness of the tip 25a of the protrusion 25 is smaller than the thickness of the bottom 26a of the recess 26.

[0017] The tip 25a of the protrusion 25 extends straight (while maintaining the same diameter) in the extension direction of the axis S. The bottom 26a of the recess 26 extends straight in the extension direction of the axis S. The tips 25a and bottoms 26a of adjacent protrusions 25 and recesses 26 are connected via boundary walls 25b, 26b that extend continuously in a direction perpendicular to the axis S.

[0018] "N" in the drawings indicates the outer diameter of the bottom 26a in the recess 26. As shown in Fig. 5, the outer diameter N is smaller than the inner diameter M of the pipe insertion opening 16a in the fastening ring 16 of the pipe fitting 11. Therefore, when the tip of the sleeve pipe 23 that faces the pipe fitting 11 is provided by the bottom 26a of the recess 26, construction is possible in which the bottom 26a is positioned within the pipe insertion opening 16a of the fastening ring 16 when the pipe fitting 11 and the pipe body 22 are connected.

[0019] 1 and 3 indicates the distance between the centers of the tips 25a of the projections 25 and the bottoms 26a of the recesses 26 in the extension direction of the axis S of the sheath pipe 23. As shown in FIG. 1, the distance K between the insertion marks 22a in the pipe main body 22 is an odd multiple of the distance P between the projections 25 and the recesses 26 of the sheath pipe 23.

[0020] 1, it is assumed that the sheath tube 23 and the pipe body 22 are positioned in the extension direction of the axis S so that one insertion mark 22a (22a-1) of the pipe body 22 appears to overlap with the bottom 26a of the recess 26 in the sheath tube 23 in a direction perpendicular to the axis S. In this positioned state, another insertion mark 22a (22a-2) adjacent to the one insertion mark 22a (22a-1) appears to overlap with the tip 25a of the protrusion 25 in a direction perpendicular to the axis S.

[0021] Conversely, although not shown, it is assumed that the sheath pipe 23 and the pipe body 22 are positioned so that one insertion mark 22a (22a-1) of the pipe body 22 appears to overlap with the tip 25a of the convex portion 25 in the sheath pipe 23. In this positioned state, another insertion mark 22a (22a-2) adjacent to the one insertion mark 22a (22a-1) appears to overlap with the bottom 26a of the concave portion 26.

[0022] Although not shown, as another example of this embodiment, the interval K of the insertion marks 22a may be an even multiple of the interval P between the convex portion 25 and the concave portion 26 in the sheath pipe 23. In this case, it is assumed that the sheath pipe 23 and the pipe main body 22 are positioned in the extension direction of the axis S so that one insertion mark 22a (22a-1) of the pipe main body 22 appears to overlap with the bottom 26a of the concave portion 26 in the sheath pipe 23 in a direction perpendicular to the axis S. In this positioned state, another insertion mark 22a (22a-2) adjacent to the one insertion mark 22a (22a-1) appears to overlap with the bottom 26a of another concave portion 26 in a direction perpendicular to the axis S.

[0023] Conversely, suppose that the sheath pipe 23 and the pipe body 22 are positioned so that one insertion mark 22a (22a-1) of the pipe body 22 appears to overlap with the tip 25a of the convex portion 25 in the sheath pipe 23. In this positioned state, another insertion mark 22a (22a-2) adjacent to the one insertion mark 22a (22a-1) appears to overlap with the tip 25a of a convex portion 25 other than the one insertion mark 22a (22a-1).

[0024] Next, an example of the operation of connecting the sheath pipe 21 to the pipe joint 11 will be described.

[0025] A pipe with a sheath pipe 21 is connected to the pipe fitting 11 shown in Fig. 4 as shown in Fig. 5. In this case, the sheath pipe 23 and the pipe body 22 are positioned in the extending direction of the axis S so that one of the insertion marks 22a (22a-1) of the insertion marks 22a on the pipe body 22 appears to overlap with the bottom 26a of the recess 26 on the sheath pipe 23 in a direction perpendicular to the axis S as shown in Fig. 1. In this state, the sheath pipe 23 and the pipe body 22 are cut in one go with a tool, using the one insertion mark 22a (22a-1) that is visible through the bottom 26a of the recess 26 on the sheath pipe 23 as a guide.

[0026] 5, after cutting the sleeve tube 23 and the pipe body 22, the tip (cut end) of the pipe body 22 is inserted into the insertion space 27 of the pipe fitting 11. If it can be confirmed through the sleeve tube 23 that another insertion mark 22a (22a-2) adjacent to one insertion mark 22a (22a-1) at a distance K has moved to the end of the pipe fitting 11, that is, to the pipe insertion port 16a of the tightening ring 16, it can be determined that the insertion allowance of the pipe body 22 into the pipe fitting 11 approximately matches the insertion depth L of the pipe fitting 11, and that the connection is properly established.

[0027] The above embodiment provides the following advantages. (1) The sleeve pipe 23 is transparent. Therefore, when cutting the pipe body 22, there is no need to take the trouble of exposing one insertion mark 22a (22a-1) from the sleeve pipe 23. In addition, when inserting the pipe body 22 into the pipe fitting 11, there is no need to take the trouble of exposing another insertion mark 22a (22a-2) from the sleeve pipe 23.

[0028] (2) For example, when the sheath tube 23 and the pipe body 22 are positioned so that one insertion mark 22a (22a-1) of the pipe body 22 appears to overlap with the bottom 26a of the recess 26 in the sheath tube 23, another insertion mark 22a (22a-2) adjacent to the one insertion mark 22a (22a-1) appears to overlap with the tip 25a of the protrusion 25. Therefore, the visibility of the insertion marks 22a (22a-1, 22a-2) is improved compared to the case where these insertion marks 22a (22a-1, 22a-2) appear to overlap with the boundary walls 25b, 26b that are thick in the radial direction.

[0029] Therefore, it is possible to accurately cut the sleeve tube 23 and the pipe body 22 using one insertion mark 22a (22a-1) as a guide. Furthermore, when checking another insertion mark 22a (22a-2) after the cutting, there is no need to reposition the tip 25a of the convex portion 25 or the bottom 26a of the concave portion 26 in order to clearly check the other insertion mark 22a (22a-2), and a smooth transition from the cutting process to the insertion process can be made.

[0030] 1, the insertion mark 22a (22a-3) far away from the first insertion mark 22a (22a-1) has poor visibility because it appears to overlap with the radially thick boundary walls 25b, 26b rather than with the tip 25a of the convex portion 25 or the bottom 26a of the concave portion 26. However, the insertion mark 22a (22a-3) has little utility in this construction, and poor visibility does not cause any problem.

[0031] In this sense, "the spacing K of the insertion marks 22a is an odd or even multiple of the spacing P between the convex portion 25 and the concave portion 26" is not limited to being an exact odd or even multiple such that all of the insertion marks 22a appear to overlap the tip 25a of the convex portion 25 or the bottom 26a of the concave portion 26. It is sufficient that only one insertion mark 22a (22a-1) used in the cutting process and another insertion mark 22a (22a-2) used in the insertion process appear to overlap the tip 25a of the convex portion 25 or the bottom 26a of the concave portion 26.

[0032] (3) When the pipe fitting 11 and the pipe body 22 are connected, the bottom 26a of the recess 26 in the sleeve pipe 23 can be positioned within the pipe insertion opening 16a of the pipe fitting 11. Therefore, the pipe body 22 is less likely to be exposed from the sleeve pipe 23 and the pipe fitting 11, improving the appearance of the installation area and making the pipe body 22 less susceptible to the effects of ultraviolet rays and the like, thereby extending the life of the pipe body 22.

[0033] In this way, when the bottom 26a of the recess 26 in the sheath tube 23 is located within the pipe insertion opening 16a of the pipe fitting 11, the sheath tube 23 is more likely to be caught by the pipe fitting 11 (fastening ring 16) when the sheath tube 23 is pulled out from the pipe insertion opening 16a, compared to when the bottom 26a is not located. In this sense, the fact that the sheath tube 23 is transparent is particularly effective because it allows the positional relationship between the other insertion mark 22a (22a-2) and the pipe insertion opening 16a to be confirmed through the light without pulling out the sheath tube 23 from the pipe insertion opening 16a during subsequent inspections such as checking the installation.

[0034] (4) In the sheath tube 23, the tip 25a of the protrusion 25 has a small thickness. Therefore, even though the tip 25a is located radially away from the pipe body 22, the visibility of the insertion mark 22a that appears to overlap with the tip 25a is good. In addition, the bottom 26a of the recess 26 in the sheath tube 23 has a large thickness, which contributes to improving the durability of the sheath tube 23. Since the bottom 26a is located radially close to the pipe body 22, the visibility of the insertion mark 22a that appears to overlap with the bottom 26a is good even if the bottom 26a is thick. In order to achieve both of these at a high level, it is preferable that the thickness of the bottom 26a in the recess 26 is about 1.2 to 2 times the thickness of the tip 25a in the protrusion 25.

[0035] (Another example) The above embodiment can be modified, for example, as follows. The tip 25a of the protrusion 25 is curved (has a variable diameter) in the direction in which the axis S extends.

[0036] The bottom 26a of the recess 26 extends in a curved manner in the direction in which the axis S extends.

[0037] The outer diameter of the tip 25a of the protrusion 25 of the sleeve pipe 23 is made smaller than the inner diameter M of the pipe insertion opening 16a in the pipe fitting 11. In this way, even if the tip of the sleeve pipe 23 that faces the pipe fitting 11 is provided by the tip 25a of the protrusion 25, the tip 25a can be positioned within the pipe insertion opening 16a of the tightening ring 16 when the pipe fitting 11 and the pipe body 22 are connected.

[0038] (Additional Note) The technical ideas that can be understood from the above embodiment will be described. (1) A pipe with a sheath tube, comprising: a sheath tube made of a transparent resin material and having an accordion-like shape in which convex portions and concave portions are alternately arranged in the extension direction of an axis and is expandable and contractable in the extension direction; and a pipe body inserted into the sheath tube and having a plurality of insertion marks for a pipe fitting attached at equal intervals in the extension direction, wherein the pipe fitting is provided with a retaining ring that bites into an outer peripheral surface of the pipe body exposed from the sheath tube to prevent the pipe body from slipping out of the pipe fitting, and the outer diameter of the bottom of the concave portion of the sheath tube is smaller than the maximum inner diameter on the opening side of a pipe insertion port of the pipe fitting and larger than the minimum inner diameter on the rear side of the pipe insertion port. According to this configuration, since the sleeve pipe is transparent, there is no need to take the trouble of exposing the insertion mark from the sleeve pipe when checking the insertion mark on the pipe body. [Explanation of symbols]

[0039] 11...pipe fitting, 16a...pipe insertion port, 21...pipe with sleeve tube, 22...pipe body, 22a...insertion mark, 22a-1...first insertion mark, 22a-2...another insertion mark, 23...sleeve tube, 25...convex portion, 25a...tip, 26...concave portion, 26a...bottom.

Claims

[Claim 1] A pipe with a sheath tube comprising: a sheath tube having an accordion-like shape in which convex portions and concave portions are alternately arranged in the extension direction of an axis and being expandable and contractable in the extension direction, and a pipe body inserted into the sheath tube, wherein the pipe fitting is provided with a retaining ring that bites into an outer peripheral surface of the pipe body exposed from the sheath tube to prevent the pipe body from slipping out of the pipe fitting, and the outer diameter of the bottom of the concave portion in the sheath tube is smaller than a maximum inner diameter on the opening side of a pipe insertion port of the pipe fitting and larger than a minimum inner diameter on the rear side of the pipe insertion port.

Images