JP4801531B2 - Protective tube or sheath tube - Google Patents

Description

  The present invention relates to an improvement in a protective tube made of synthetic resin and a sheath tube that protect flexible fluid tubes such as a water supply pipe and a hot water supply pipe disposed on a floor surface or a wall surface of a structure.

  In general, when a fluid pipe such as a hot water supply pipe or a heating pipe is installed in a structure such as a detached house or a high-rise house, it is made of a flexible synthetic resin that is arranged in advance on the floor or wall surface of the structure. A double piping method is employed in which a flexible fluid pipe is inserted into the protective pipe or the sheath pipe. In the case of this double piping method, although the construction and maintenance of the fluid pipe can be facilitated and streamlined, the fluid pipe is protected or sheathed by the undulation of the fluid pipe due to the water hammer phenomenon. There is a problem that a sound is generated by colliding with the inner wall surface.

  For this reason, as a measure for suppressing the occurrence of a collision sound due to the undulation of the fluid pipe due to such a water hammer phenomenon, conventionally, the peripheral wall of the corrugated flexible resin pipe made of a bendable synthetic resin that passes through the fluid pipe is used. The buffer ridges projecting radially inward at four locations in the direction are integrally formed along the tube axis direction, and each buffer ridge is formed with a thickness smaller than the thickness of the corrugated flexible tube. When viewed from the direction, the inner wall surface of the corrugated flexible tube is composed of a cantilevered thin strip that is bent or bent in the direction of warping, and the tip of each thin strip is in contact with the inserted fluid tube. It is comprised so that it may contact | abut to the inner wall face of a corrugated flexible tube with the elastic deformation of the thin strip piece by (For example, refer FIGS. 2-4 of patent document 1).

  Further, as another countermeasure method for suppressing the generation of the collision noise, buffer protrusions protruding inward in the radial direction are integrally formed along the tube axis direction at four locations in the circumferential direction on the inner wall surface of the corrugated flexible tube. In addition, there has been proposed a structure in which each of the buffer protrusions is formed by aggregating a plurality of thin sheet strips having different thicknesses with a thickness smaller than the thickness of the corrugated flexible tube (for example, Patent Document 1). FIG. 12).

JP 2006-52770 A

  In the former former sheath tube, when the fluid tube inserted into the corrugated flexible tube undulates due to the water hammer phenomenon, the buffer ridges are formed to project at four locations in the circumferential direction of the inner wall surface of the corrugated flexible tube. Is elastically deformed as it comes into contact with the fluid pipe, so that the impact force caused by the undulation of the fluid pipe can be reduced, and the buffer ridges have a thickness smaller than the thickness of the corrugated flexible pipe. In view of the tube axis direction, the thin plate strip itself is formed of a cantilevered thin strip that is curved or bent in a direction opposite to the inner wall surface of the corrugated flexible tube. It is easy to deform following the bending, and the adverse effect on the bending characteristics of the sheath tube can be reduced.

  However, when the buffer ridge is thinned as described above, the tip of the thin plate-like piece is brought into contact with the inner wall surface of the corrugated flexible tube as the thin plate-like piece is elastically deformed by contact with the inserted fluid pipe. Even if they are brought into contact with each other, the spring property of the thin plate-like piece itself is weak, and there is a problem that the function of reducing the impact force caused by the wave of the corrugated fluid pipe caused by the water hammer phenomenon is lowered.

  Further, in the latter sheath tube, each of the buffer ridges is formed by aggregating a plurality of thin plate strips having a thickness smaller than that of the corrugated flexible tube and having different lengths. Although it can improve the function of mitigating the impact force caused by the corrugated fluid tube's undulation caused by the phenomenon, the bending characteristics of the sheath tube can be achieved by forming multiple thin strips on the inner wall surface of the corrugated flexible tube. In addition to increasing the adverse effect on the tube, there is a disadvantage that the insertion resistance of the fluid pipe to the sheath pipe is increased.

  The present invention has been made in view of the above-mentioned actual situation, and its main problem is that the impact force caused by the undulation of the fluid pipe caused by the water hammer phenomenon can be effectively mitigated, It is in the point which aims at the improvement of piping work efficiency by suppressing the fall of the bending characteristic of a flexible tube or a corrugated flexible tube, and reducing the insertion resistance of a fluid pipe.

  The first characteristic configuration according to the present invention is such that the inner surface of the flexible tube made of a synthetic resin that can be inserted through the flexible fluid tube extends toward the tube axis and into the region where the fluid tube is disposed. An extended elastically deformable protrusion piece is integrally formed, and an insertion guide portion for a fluid pipe that is thicker than the thickness of other portions is integrally formed at the tip of the protrusion piece.

  According to the above characteristic configuration, the protrusion piece integrally formed on the inner wall surface of the flexible pipe is elastically deformed as the fluid pipe is inserted into the flexible pipe, and the elastic restoring force of the protrusion piece causes the fluid to flow. By pressing the pipe against the inner wall surface of the flexible pipe, when the fluid pipe inserted into the flexible pipe undulates due to the water hammer phenomenon, the impact force caused by the undulation of the fluid pipe can be effectively reduced. it can.

  And since the said protrusion piece is extended even in the arrangement | positioning area | region of the fluid pipe | tube toward the pipe-axis core side, it is twisted with the contact with the fluid pipe | tube inserted, and it goes out of an arrangement | positioning area | region. Since it becomes easy to elastically deform, and at this time, the insertion guide part integrally formed at the tip of the protrusion piece can be elastically deformed smoothly while the protrusion piece is curved by contact with the fluid pipe, The insertion resistance of the fluid pipe can be reduced without being entangled with or in close contact with the fluid pipe into which the protrusion is inserted.

  Therefore, while the impact force caused by the undulation of the fluid pipe caused by the water hammer phenomenon can be effectively reduced, the piping is reduced by suppressing the bending characteristic of the flexible pipe and reducing the insertion resistance of the fluid pipe. The work efficiency can be improved, and furthermore, since the protrusion piece itself can be simply modified, the existing equipment can be utilized advantageously in terms of cost.

  A second characteristic configuration according to the present invention is that, on the inner wall surface of a corrugated flexible tube made of a bendable synthetic resin that passes through a flexible fluid tube, in the region where the fluid tube is disposed toward the tube axis side. An elastically deformable ridge piece extending up to is integrally formed, and an insertion guide portion for a fluid pipe that is thicker than the thickness of other portions is integrally formed at the tip of the ridge piece.

  According to the above characteristic configuration, the protrusion piece integrally formed on the inner wall surface of the corrugated flexible pipe is elastically deformed as the fluid pipe is inserted into the corrugated flexible pipe, and the elastic restoring force of the protrusion piece By pressing the fluid pipe against the inner wall surface of the corrugated flexible pipe with the water hammer, when the fluid pipe inserted into the corrugated flexible pipe undulates due to the water hammer phenomenon, the impact force caused by the undulation of the fluid pipe is effectively reduced. Can be relaxed.

  And since the said protrusion piece is extended even in the arrangement | positioning area | region of the fluid pipe | tube toward the pipe-axis core side, it is twisted with the contact with the fluid pipe | tube inserted, and it goes out of an arrangement | positioning area | region. Since it becomes easy to elastically deform, and at this time, the insertion guide part integrally formed at the tip of the protrusion piece can be elastically deformed smoothly while the protrusion piece is curved by contact with the fluid pipe, The insertion resistance of the fluid pipe can be reduced without being entangled with or in close contact with the fluid pipe into which the protrusion is inserted.

  Therefore, the impact force caused by the wave of the fluid pipe caused by the water hammer phenomenon can be effectively mitigated, while the bending characteristic of the corrugated flexible pipe is suppressed from being lowered and the insertion resistance of the fluid pipe is reduced. The piping work efficiency can be improved, and furthermore, since the protrusion piece itself can be simply modified, the existing equipment can be utilized advantageously in terms of cost.

  A third characteristic configuration according to the present invention is that the thickness of the other part of the protruding strip is configured to be smaller than the thickness of the corrugated flexible tube.

  According to the above characteristic configuration, the strip piece itself can be easily deformed smoothly following the bending of the corrugated flexible tube, and the adverse effect on the bending characteristics of the corrugated flexible tube can be reduced. Since it is easy to be elastically deformed with the insertion of the fluid pipe, it is possible to promote the reduction of the insertion resistance of the fluid pipe and improve the piping work efficiency.

  The 4th characteristic structure by this invention exists in the point by which the insertion guide part of the said protrusion piece is arrange | positioned in the sheath pipe axial core or its vicinity position.

  According to the above characteristic configuration, the length from the distal end to the proximal end of the projecting piece is increased, and the reduction of the insertion resistance of the fluid pipe can be promoted by the smooth elastic deformation of the projecting piece.

  A fifth characteristic configuration according to the present invention is that the insertion guide portion of the protruding piece is configured in a columnar shape.

  According to the above-described characteristic configuration, the protruding strip projecting into the fluid pipe arrangement area is elastically deformed outside the arrangement area while being twisted in contact with the fluid pipe to be inserted. When the columnar insertion guide part integrally formed at the tip of the ridge piece is bent by contact with the fluid pipe, the ridge piece can be elastically deformed more smoothly, so that the ridge piece is inserted. Therefore, it is possible to improve the piping work efficiency by reducing the insertion resistance of the fluid pipe.

[First Embodiment]
1 to 4 are examples of fluid pipes having flexibility made of synthetic resin in a corrugated flexible pipe 1 made of crosslinked polyethylene constituting a flexible sheath pipe P made of synthetic resin. A double-pipe structure is shown in which a cross-linked polyethylene water supply hot water supply pipe 2 is inserted and a sheath pipe P is formed as a protective pipe for the water supply hot water supply pipe 2, and the circumferential direction of the inner wall surface 1a of the corrugated flexible pipe 1 is shown. In a specific location (one location in the embodiment), a buffered bump made of cross-linked polyethylene that can come into contact with the outer peripheral surface 2a of the hot water supply pipe 2 at a radially inner position than the inner peripheral surface of the valley portion 1B. The strip 3 is integrally formed along the tube axis (tube axis) X direction.

  The buffer ridge 3 is provided in a region where the hot and cold water supply pipes 2 are arranged from one place on the inner wall surface 1a of the corrugated flexible tube 1 in the direction of the tube axis X (hereinafter referred to as an inner tube arrangement region). And a long elastically deformable protruding strip 3A extending into S and branched from the proximal end portion of one surface of the elongated protruding strip 3A toward the tube axis X side. And the thickness of each of the long and short ridge pieces 3A and 3B is smaller than the thickness of the corrugated flexible tube 1, A portion where the branch position of the short ridge piece 3B with respect to the long ridge piece 3A is slightly deviated more radially inward (to the tube axis X side) than the inner peripheral surface of the valley portion 1B in the corrugated flexible tube 1 Is set to

  Along with the insertion of the hot water supply pipe 2 into the corrugated flexible pipe 1, the elongated protrusion 3A of the buffer projection 3 formed to project at a specific location on the inner wall surface 1a of the corrugated flexible pipe 1 is elastically deformed, The water supply hot water pipe 2 is pressed against the inner wall surface 1a of the corrugated flexible pipe 1 by the elastic restoring force of the long ridge piece 3A, and the elastic deformation of the long ridge piece 3A to the outside of the inner pipe arrangement region S is further performed. Accordingly, the short ridge piece 3B can come into contact with the outer peripheral surface 2a of the water supply hot water pipe 2, and the short ridge piece 3B and the long ridge piece 3A cooperate to cause a water hammer phenomenon. When the hot water supply hot water pipe 2 inserted into the corrugated flexible pipe 1 undulates, the impact force caused by the undulation of the hot water supply hot water pipe 2 can be effectively reduced.

  Further, since the short protrusion 3B is branched from the proximal end portion of the long protrusion 3A toward the tube axis X side, the proximal end portion 3a of the long protrusion 3A itself is thin. Further, the length of the long ridge 3A and the length of the short ridge 3B can be made smaller than the thickness of the corrugated flexible tube 1 by configuring each thickness of the long ridge 3A and the short ridge 3B. Each of the protrusions 3B is easily elastically deformed as the water supply hot water supply pipe 2 is inserted. For example, the corrugated flexible pipe 1 is corrugated as compared with a case where a plurality of thin sheet strips are formed on the inner wall surface 1a of the corrugated flexible pipe 1. The adverse effect on the bending characteristics of the flexible tube 1 can be reduced.

  The long ridge piece 3A has a length slightly exceeding the tube axis X of the corrugated flexible tube 1, and has a circular cross section (at the tip thereof, thicker than the thickness of the long ridge piece 3A). An insertion guide portion 3D for the water supply hot water supply pipe 2 having a cylindrical shape is integrally formed, and the elongated protrusion 3A is formed in a gentle wave shape or a plurality of curved shapes similar thereto, and further, The base end portion 3a of the protruding strip 3A is integrally and continuously formed over the entire region in the tube axis X direction along the peak portion 1A and the valley portion 1B constituting the inner wall surface 1a of the corrugated flexible tube 1.

  The elongated protrusion 3A protruding into the inner pipe arrangement area S is elastically deformed outside the inner pipe arrangement area S while being twisted in contact with the inserted water / hot water supply pipe 2. At this time, since the insertion guide portion 3D integrally formed at the tip of the long ridge piece 3A can be bent by contact with the water supply and hot water supply pipe 2, the long ridge piece 3A can be elastically deformed smoothly. The pipe work efficiency can be improved by reducing the insertion resistance of the hot water supply hot water pipe 2 without being entangled or in close contact with the hot water hot water supply pipe 2 into which the long protruding strip 3A is inserted.

  The length of the short protrusion 3B is in contact with the outer peripheral surface 2a of the inserted hot water / hot water pipe 2 while being slightly elastically deformed, or in contact with or close to the outer peripheral surface 2a of the hot water / hot water pipe 2 in an unloaded state. 3A and the short ridge piece 3B are formed so as to be curved in an arc shape spaced apart from the side surface of the long ridge piece 3A toward the radial center in the tube axis X direction view. A gap 3C is formed between the two surfaces, and the tip of the short ridge piece 3B is in contact with or in close proximity to the long ridge piece 3A so as to be relatively movable.

  Even if the elongated protrusion 3A is elastically deformed outside the inner pipe disposition region S as the water supply hot water supply pipe 2 is inserted, the tip of the elongated protrusion 3B is in relation to the elongated protrusion 3A. Since it can be moved relative to each other, the short protrusion 3B is branched from the long protrusion 3A, but the positional deviation of the tip of the short protrusion 3B is suppressed, and the desired buffer function is reliably exhibited. In addition, it is possible to exhibit an excellent spring property by forming the curved pieces 3A and 3B.

Next, a method of manufacturing the sheath pipe P configured as described above using a blow molding machine A as shown in FIGS. 5 and 6 will be described.
In the blow molding machine A, the upper half side of the outer wall surface 1b of the corrugated flexible tube 1 is located on both sides of the blow molding center line passing through the center line of the die 6 and the tube axis X of the corrugated flexible tube 1 to be blow molded. A first circulation path R for circulating and moving a large number of divided molds 5A having a semi-cylindrical tube wall forming surface 4A with respect to the outer wall surface, and a lower half side outer wall surface in the outer wall surface 1b of the corrugated flexible tube 1 A second circulation path L that circulates and moves a large number of divided molds 5B each having a cylindrical tube wall molding surface 4B, and an annular ring formed in the die 6 of the circulation paths R and L. The pair of split molds 5A and 5B that move back along the return path portions are joined together at the start end of the molding path portion corresponding to the first resin extrusion port 7 and both split in the joined state. Mold 5A, 5B is the end of the molding path And it is configured to move toward the side.

  Further, the die 6 of the blow molding machine A has an annular first resin extrusion port 7 for continuously extruding a heat-softened parison 8 for molding the corrugated flexible tube 1, and a first resin extrusion port 7. And an air outlet 9 for injecting pressurized air for pressing the heat-softened parison 8 continuously extruded from the pipe wall molding surfaces 4A and 4B of the split molds 5A and 5B with a blow pressure. .

  And in the circumferential direction used as the vertex of the 1st resin extrusion port 7 of the said die | dye 6, the heat-softened thin plate-shaped or film-plate-shaped resin for shape | molding the elongate protrusion piece 3A of the buffer protrusion 3 is provided. In order to extrude 8A on the inner wall surface of the parison 8 in a continuous fusion or fusion state, the four portions of the elongated protrusion 3A are set in an arcuate shape in a counterclockwise direction when viewed in the tube axis X direction. A slit-shaped second resin extrusion port 7 </ b> A that is curved or bent in a substantially C-shape is formed to communicate with the first resin extrusion port 7 so as to cut radially inward.

  Further, on the base side of the second resin extrusion port 7A of the die 6, a heat-softened thin plate-like or membrane-like resin 8B for forming the short ridge piece 3B of the buffer ridge 3 is a long ridge. In order to extrude in the state of fusion or fusion continuous with the thin plate-like or membrane plate-like resin 8A for molding the piece 3A, the short ridge piece 3B is set in an arcuately curved state in the clockwise direction in the tube axis X direction view. A slit-shaped third resin extrusion port 7B that is curved or bent in an arc shape is formed in communication.

  Of the two circulation paths R and L, the divided molds 5A and 5B are joined and moved in the molding path portion corresponding to the annular first resin extrusion port 7 formed in the die 6 of the blow molding machine A. The heat-softened cylindrical parison 8 continuously extruded from the first resin extrusion port 7 of the blow molding machine A is formed on the tip of the die 6 and the pressure air injected from the air outlet 9 is discharged. While being pressed against the pipe wall molding surfaces 4A and 4B of both split molds 5A and 5B by the blow pressure, it is radially inwardly formed at one circumferential position that becomes the apex of the first resin extrusion port 7 of the die 6 The second resin extrusion port portion is simultaneously extruded from the slit-like second resin extrusion port 7A which is extruded into the thin plate-like or membrane plate-like resin 8A which has been heat-softened continuously or fused to the inner wall surface of the parison 8. 7th communicating with the base end side of 7A By extruding a thin plate-like or membrane-plate-like resin 8B heat-softened in a continuous fusion or fusion state to a thin plate-like or membrane-like plate-like resin 8A for molding the elongated protrusion 3A from the resin extrusion port 7B, a tube is obtained. A cantilevered long strip 3A that is curved or bent into a wave shape or a plurality of curved surfaces when viewed in the axial direction of the axial center X, and a short length branched from the proximal end portion toward the tubular axial core X side. The corrugated flexible tube 1 integrally molded with the protruding strip 3B is blow-molded.

  The second resin extrusion port portion 7A is formed in communication with the apex of the first resin extrusion port 7, and the cross section of the long projection strip 3A is thicker than the thickness of the long projection strip 3A. Since the circular insertion guide portion 3D is integrally formed, the insertion guide portion 3D serves as a weight, and the thin plate-like or membrane plate-like resin 8B extruded in a substantially C shape from the second resin extrusion port portion 7A gradually. Since the second resin extrusion port portion 7A of the die 6 does not need to be formed in the same shape as the long protrusion 3A, the die 6 can be easily manufactured.

  In addition to the crosslinked polyethylene pipe described in the first embodiment, the fluid pipe 2 such as the water supply / hot water pipe is a composite resin pipe having flexibility such as a polyethylene pipe and a polybutene pipe, and a metal composite. The flexible metal composite synthetic resin tube which has been made can be suitably used.

Further, as the corrugated flexible tube 1, in addition to the crosslinked polyethylene tube described in the first embodiment, a flexible corrugated or straight synthetic resin tube such as a polyethylene tube or a polybutene tube is preferably used. be able to.
The flexible tube 1 may be a straight tube other than a corrugated tube.

  Note that a low friction material such as silicon may be applied to the inner surface of the flexible tube 1 in order to smoothly insert the fluid tube 2 such as a hot and cold water supply tube into the flexible tube 1.

[Second Embodiment]
In the first embodiment described above, the tip of the short ridge piece 3B is arranged in contact with or in close proximity to the long ridge piece 3A so as to be relatively movable. However, as shown in FIG. The tip of the strip 3B may be integrally formed with the long strip 3A in a cylindrical state that forms a gap 3C that is closed between the opposing faces of the long strip 3A.

Since the base end side portion of the long ridge piece 3A and the short ridge piece 3B constitute a cylindrical portion having a gap 3C, the base end side portion of the long ridge piece 3A and the short ridge piece 3B Excellent spring properties can be ensured while reducing the thickness, and the impact force received from the water / hot water supply pipe 2 can be effectively reduced.
In addition, since the other structure is the same as the structure demonstrated in 1st Embodiment, the same number is attached to the same structure location as 1st Embodiment, and the description is abbreviate | omitted.

[Third Embodiment]
In the first embodiment described above, the elongated protrusion 3A is configured to have a length slightly exceeding the tube axis X of the corrugated flexible tube 1 including the insertion guide portion 3D formed at the tip thereof. The insertion guide portion 3D does not contact the inner wall surface 1a of the corrugated flexible tube 1 even when the elongated protrusion 3A is elastically deformed out of the inner tube disposition region S as the water supply hot water supply tube 2 is inserted. However, as shown in FIG. 8, the length of the long ridge piece 3 </ b> A is made elastic as the long ridge piece 3 </ b> A moves out of the inner pipe arrangement region S as the water supply hot water supply pipe 2 is inserted. When deformed, the insertion guide portion 3D comes into contact with the inner wall surface 1a of the corrugated flexible tube 1 and the middle portion of the elongated protruding strip 3A is curved and deformed in an arc shape along the outer peripheral surface 2a of the water and hot water supply tube 2. You may comprise in length.
In addition, since the other structure is the same as the structure demonstrated in 1st Embodiment, the same number is attached to the same structure location as 1st Embodiment, and the description is abbreviate | omitted.

[Fourth Embodiment]
In the first embodiment described above, the short ridge piece 3B is branched from the proximal end portion of one side of the long ridge piece 3A toward the tube axis X side, as shown in FIG. The short ridge piece 3B may be branched from the proximal end portions on both sides of the long ridge piece 3A toward the tube axis X side.
In addition, since the other structure is the same as the structure demonstrated in 1st Embodiment, the same number is attached to the same structure location as 1st Embodiment, and the description is abbreviate | omitted.

[Other Embodiments]
(1) In the above-described first embodiment, the elongated protrusion 3A is configured to have a length slightly exceeding the tube axis X of the corrugated flexible tube 1 including the insertion guide portion 3D formed at the tip thereof. However, the length of the elongated protrusion 3 </ b> A may be formed such that the tip thereof is positioned on the tube axis X of the corrugated flexible tube 1 or slightly shorter than that.

(2) In the above-described first embodiment, the insertion guide portion 3D formed at the tip of the elongated protrusion 3A is formed in a circular cross section. You may form in a rounded-corner triangle shape, polygonal shape, etc.
In short, the insertion guide portion 3D may be formed in any shape as long as it is thicker than the elongated protrusion 3A and enhances the insertion guide function of the fluid pipe 2 such as a water supply hot water supply pipe.

(3) In the above-described fourth embodiment, the short ridge piece 3B having the same length is branched from the same position near the base ends of both surfaces of the long ridge piece 3A. The short ridge pieces 3B having different lengths may be branched from the same position near the base ends of both surfaces, and the short ridges having the same length or different lengths may be formed at different positions on both surfaces of the long ridge piece 3A. The protruding strip 3B may be branched.

  (4) In each of the above-described embodiments, the outer periphery of the hot and cold water supply pipe 2 is located at one position in the circumferential direction on the inner wall surface 1a of the corrugated flexible pipe 1 at a position radially inward from the inner circumferential surface of the valley portion 1B. The buffer ridges 3 that can come into contact with the surface 2a are integrally formed along the tube axis (tube axis) X direction. The buffer ridges 3 are formed at a plurality of locations in the circumferential direction on the inner wall surface 1a of the corrugated flexible tube 1. You may form integrally.

  (5) In the first embodiment described above, the branch position of the short ridge piece 3B with respect to the long ridge piece 3A is set radially inward from the inner peripheral surface of the valley portion 1B in the corrugated flexible tube 1 ( Although it was set to a part slightly deviated to the tube axis X side), the branch position of this short protrusion 3B was set to the same position as or the vicinity of the inner peripheral surface of the valley portion 1B in the corrugated flexible tube 1 Also good.

  (6) In each of the above-described embodiments, the base end portion 3a of the buffer projection 3 is the entire region in the tube axis X direction along the peak portion 1A and the valley portion 1B constituting the inner wall surface 1a of the corrugated flexible tube 1. However, the base end portion 3 a of the buffer protrusion 3 may be integrally formed only on the inner peripheral surface of the valley portion 1 </ b> B in the corrugated flexible tube 1.

The cross-sectional view of the sheath pipe which shows 1st Embodiment of this invention II-II sectional view of FIG. III-III sectional view of FIG. Cross section when inserted through hot and cold water supply pipes Explanatory drawing which shows the blow molding manufacturing method of a corrugated flexible tube Sectional view taken along line VI-VI in FIG. Cross-sectional view of a sheath tube showing a second embodiment of the present invention Cross-sectional view of a sheath tube showing a third embodiment of the present invention Cross-sectional view of a sheath tube showing a fourth embodiment of the present invention

Explanation of symbols

P protective tube (sheath tube)
S Fluid pipe placement area (inner pipe placement area)
X tube axis 1 corrugated flexible tube (flexible tube)
1a Inner wall surface 2 Fluid pipe (water supply hot water supply pipe)
2a Outer peripheral surface 3 Buffer protrusion 3A Long protrusion 3B Short protrusion 3D Insertion guide part 3a Base end part 11 Insertion guide part

Claims (5)

  An elastically deformable ridge piece extending on the inner wall surface of a flexible tube made of a synthetic resin that can be bent through a flexible fluid tube and extending toward the tube axis toward the region where the fluid tube is disposed. Is a protection tube in which an insertion guide part for a fluid pipe that is thicker than the thickness of the other part is integrally formed at the tip of the protruding piece.   An elastically deformable ridge extending on the inner wall surface of a corrugated flexible tube made of a bendable synthetic resin, which is inserted through a flexible fluid tube, into the region where the fluid tube is disposed toward the tube axis. A sheath tube in which a piece is integrally formed, and an insertion guide portion for a fluid tube that is thicker than the thickness of other portions is integrally formed at the tip of the protruding piece.   The sheath tube according to claim 2, wherein the thickness of the other portion of the protruding piece is configured to be smaller than the thickness of the corrugated flexible tube.   The sheath tube according to claim 2 or 3, wherein the insertion guide portion of the protruding piece is disposed at the sheath tube axis or in the vicinity thereof. The sheath tube according to claim 2, 3, or 4, wherein the insertion guide portion of the protruding piece is configured in a columnar shape.

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