JPH1066223A - Underground flexible coupling tube - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an underground flexible coupling tube used for easy piping arrangement even at a bent part, in which its bent angle is limited like a protective tube to protect a communication cable from damage or an optical fiber from deterioration in communication effect. SOLUTION: A flexible coupling tube 1 includes a hard flexible tube 2 formed by turning a hard synthetic resin-type belt-shaped body 5 spirally, and a soft synthetic resin-type coating layer 3 having a smooth face and applied around the hard flexible tube 2. The hard flexible tube 2 with an S-shaped cross section is made up of an almost linear bottom wall, an upward extending side edge part from the bottom wall on one edge thereof, a sequentially joined rising part from the bottom wall to the other edge, an upper wall part, and a downward extending side edge part. The hard flexible tube 2 is turned spirally, while the upward extending side edge part and the downward extending edge part are fitted and joined to each other in a way that an inner wall face formed by adjoining walls of the hard belt-shaped body 5 is made almost flat and smooth.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underground burial used for connecting straight pipes such as hard vinyl pipes buried underground in a non-linear manner as protection pipes for communication cables and optical fibers. The present invention relates to a flexible joint pipe.

[0002]

2. Description of the Related Art Conventionally, a protective tube for a communication cable or an optical fiber is not a corrugated hard plastic tube used as a protective tube for a power cable, but a rigid non-flexible straight tube having a smooth inner surface. Is mainly used. This is because, when a rigid plastic pipe with corrugations having excellent irregularities formed on the inner surface of the tube is used as a protective tube, the irregularities may be damaged by contact with the communication cable,
When a corrugated hard plastic tube is extremely bent, excessive bending stress is applied to the cable inserted inside the tube, and when an optical fiber is inserted, if the optical fiber is greatly bent, the communication efficiency of the optical fiber decreases. This causes a problem.

[0003]

However, there is little problem in laying underground a hard flexible pipe suitable for use as a protection pipe for a communication cable or the like in the case of laying in a straight line. Needs to be bent to avoid obstacles. In such a case, piping is performed using a bending joint, but the connecting operation is complicated, and the operation in a narrow place underground is very difficult.

Therefore, the present invention has been proposed to solve the above-mentioned problem, and is a flexible joint pipe in which the underground protection pipe can be easily bent and further extremely bent. It is an object of the present invention to provide a cable that does not damage the communication cable or lower the communication efficiency of the optical fiber, similarly to the protective tube.

[0005]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a rigid flexible tube formed by spirally winding a rigid band made of a rigid synthetic resin, and a rigid flexible tube formed of the rigid flexible tube. A flexible joint tube comprising a soft synthetic resin covering layer having a smooth surface attached to an outer periphery thereof, wherein the hard flexible tube has a substantially straight bottom wall portion and one side edge thereof. A rigid band shape having a substantially S-shaped cross-section comprising an upwardly directed side edge portion standing upright from the bottom wall portion, a rising portion, an upper wall portion and a downwardly directed side edge portion successively provided from the bottom wall portion to the other side edge. It is formed by spirally winding the body and engaging and connecting the upward side edge and the downward side edge at the adjacent side edges, and is formed by the adjacent bottom wall portions of the rigid band-shaped body. The present invention provides a flexible joint pipe for underground burial whose inner peripheral surface is formed as a substantially smooth surface.

Further, the present invention provides a coating layer in which the above-mentioned hard band is spirally wound, and at the same time, a soft band made of a soft synthetic resin is spirally wound and its side edges are joined. An object of the present invention is to provide a flexible joint pipe for burying in the ground, which is formed, and the soft band is brought into contact with the upper wall portion of the hard band to be fused and integrated.

Further, the present invention provides a flexible joint pipe for burying underground, in which connecting pipes for connecting a hard straight pipe are connected to both ends of a flexible joint pipe composed of a hard flexible pipe and a coating layer. Is provided.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the flexible joint pipe 1 for underground burial according to the present invention is formed by spirally winding a rigid band-like body 5 having a substantially S-shaped cross section made of a hard synthetic resin such as hard vinyl chloride. The rigid flexible tube 2 is formed, and a coating layer 3 made of a soft synthetic resin such as soft vinyl chloride and adhered to and integrated with the outer periphery of the rigid flexible tube 2 has a smooth surface. Short connection pipes 4 and 4 for connection are mounted at both ends as sockets for receiving a hard straight pipe such as a hard vinyl pipe which is a protection pipe such as a communication cable.

As shown in the enlarged view of FIG. 2, the rigid strip 5 having a substantially S-shaped cross section, which constitutes the rigid flexible tube 2, has a substantially straight bottom wall 6 and a bottom wall 6. An upwardly-facing side edge portion 7 that is erected and forms one side edge of the rigid band-shaped member 5, a rising portion 8 and an upper wall portion 9 that are sequentially provided from the bottom wall portion 6 to the other side edge of the rigid band-shaped member 5. And the downward edge 10 are integrally formed, and the upward edge 7 and the downward edge 10 of the adjacent side edges overlap and engage with each other to be integrally connected.

A coating layer 3 made of a soft synthetic resin and formed on the outside of the hard flexible tube 2 is in contact with the outer surface of the upper wall 9 of the hard belt 5 and is bonded and integrated. 2 and the flexible joint tube 1 is sealed to prevent water or earth and sand from entering the inside of the flexible joint tube 1 buried in wet soil. On the other hand, since the flexible joint pipe 1 is made of a soft synthetic resin, the flexibility of the flexible joint tube 1 is sufficiently maintained. The inner peripheral surface of the rigid flexible tube 2 is constituted by a linear bottom wall 6 of the rigid strip 5, and a concave portion 11 spirally formed between the adjacent bottom walls 6, 6 In order to make the gap in the axial direction as small as possible, the adjacent hard belt-shaped members 5 are wound so as to overlap each other sufficiently in the width direction, so that a substantially smooth surface is obtained as a whole.

In the present embodiment, the covering layer 3 is formed by a soft band made of a soft synthetic resin such as soft vinyl chloride extruded from an extruder (not shown) spirally on a tube forming shaft (not shown). At the same time, it is spirally wound on the outer side of the hard band 5 being wound, and the adjacent side edges are formed by fusing together, and abut on the upper wall portion 9 of the hard band 5. The rigid flexible tube 2 and the coating layer 3 are integrated.

The means for integrally forming the hard flexible tube 2 and the coating layer 3 is not limited to the above-mentioned embodiment, but is formed on the outer periphery of the hard flexible tube 2 previously formed. The tube-shaped coating layer 3 may be coated and fixed with an adhesive, or the extruded soft band may be spirally wound and integrated with the hard flexible tube 2 with an adhesive. It may be.

The connecting pipe 4 is a short pipe made of a hard synthetic resin, and has a stepped portion 4a for receiving a hard vinyl pipe inserted on an inner peripheral surface thereof. 3
Are integrally attached to both ends of the flexible joint tube 1 to which an adhesive is attached.

The underground buried flexible joint pipe 1 according to the present invention having the above-described structure is, for example, as shown in FIG.
When digging down the ground A and connecting and piping the rigid straight tubular protective tubes 12 such as communication cables, pipes cannot be connected in a straight line due to an obstacle B present in the middle of the piping, and are bypassed. It is used when the pipe must be bent. That is, in this case, the left and right protective tubes 12, 12 to be connected are connected with each other with one deviated slightly below the other, but since the flexible joint tube 1 has flexibility. Both protection tubes 12, 12 whose vertical position is deviated
The connecting pipes 4 can be easily connected by inserting and fixing the protecting pipes 12 to the connecting pipes 4 at both ends thereof.

The flexible joint tube 1 has a low frictional resistance because the inner layer 2 is made of a hard synthetic resin, so that the cable can be easily pulled in, and, like the protective tubes 12, 12, the inner surface is substantially smooth. However, even if a communication cable is inserted inside, there is no risk of damaging the communication cable. Further, since the communication cable does not have such flexibility as to be extremely bent, the communication of the optical fiber is not significantly bent. It does not adversely affect the efficiency.

Although an embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and it can be explained that various design changes can be made without departing from the gist of the invention. It is not necessary.

[0017]

The present invention provides an underground with moderate flexibility in which a hard flexible tube formed by spirally winding a hard band made of a hard synthetic resin and a coating layer made of a soft synthetic resin are fixedly integrated. Because it is related to a buried flexible joint pipe, even if the protection pipes to be connected are displaced in the up, down, left, right, front and rear positions, the protection pipes are extremely easily bent and connected by utilizing the flexibility. can do.

Further, since the inner pipe of the flexible joint pipe to be buried underground is made of a hard synthetic resin and its inner surface is formed to be substantially smooth, the cable can be smoothly inserted without damaging the cable, and furthermore, the optical fiber Does not bend so as to lower the communication efficiency of the communication. Furthermore, the connection work is very easy because it is only necessary to insert and fix the protection pipe to be connected to the connection pipe connected to both ends of the underground flexible joint pipe.

[Brief description of the drawings]

FIG. 1 is a partially sectional front view showing an embodiment of a flexible joint pipe for underground burial according to the present invention.

FIG. 2 is a partially enlarged sectional view of a flexible joint pipe for underground burial according to the present invention.

FIG. 3 is an explanatory view showing an example of a use state of the underground buried flexible joint pipe according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Flexible joint pipe for underground burial 2 Rigid flexible pipe 3 Coating layer 4 Connection pipe 5 Rigid strip 6 Bottom wall part 7 Upside edge part 8 Rise part 9 Top wall part 10 Downside edge part 11 Concave part 12 , 12 Protection tube

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Seiji Hattori 6 Titan Polymer, Shizuoka Pref. in the factory

Claims (3)

[Claims] 1. A hard flexible tube formed by spirally winding a hard band made of a hard synthetic resin, and a coating layer made of a soft synthetic resin having a smooth surface attached to the outer periphery of the hard flexible tube. A rigid joint tube comprising: a substantially straight bottom wall portion; an upwardly directed side edge portion erected from the bottom wall portion on one side edge thereof; and a bottom wall portion. A helically wound rigid band-shaped body having a substantially S-shaped cross section composed of a rising portion, an upper wall portion, and a downward side edge portion successively provided from the portion to the other side edge, and an upward side edge at an adjacent side edge And that the inner peripheral surface formed by the adjacent bottom wall portions of the rigid band-shaped body is configured to be a substantially smooth surface. A flexible joint pipe for underground burying. 2. The coating layer is formed by spirally winding the hard belt-shaped body and simultaneously spirally winding a soft band made of a soft synthetic resin and joining the side edges thereof. 2. The flexible joint pipe for underground burial according to claim 1, wherein the soft strip is in contact with an upper wall portion of the hard strip and fused and integrated. 3. The underground burial according to claim 1, wherein a connection pipe for connecting a hard straight pipe is connected to both ends of a flexible joint pipe composed of a hard flexible pipe and a coating layer. Flexible joint pipe.