JP2011027196A - Ground-buried pressure resistant synthetic resin pipe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ground-buried pressure resistant synthetic resin pipe which has excellent flexibility, keeping a sufficient pressure resistance even if a bore is large, and is suitable as a regeneration pipe of a self-supporting pipe construction method such as a sewer main. <P>SOLUTION: In the ground-buried pressure resistant synthetic resin pipe, a synthetic resin pipe wall 10 to which a reinforcement projection part 3 is spirally formed is disposed on an outer peripheral side of a body part 2 with a substantially flat inner face, structure in which a metallic band plate 4 made of a metallic thin plate is spirally disposed to the reinforcement projection part 3 of the pipe wall 10 is provided, and the reinforcement projection part 3 having the metallic band plate 4 is made of low-density polyethylene resin. Further, the body part 2 is also made of low-density polyethylene resin. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a pipe mainly used for a water pipe, a sewage (drainage) pipe, and the like, and more specifically, a sewer main having a relatively large diameter, being light and flexible, having sufficient pressure resistance. The present invention relates to a pressure-resistant synthetic resin pipe for underground burial that can be used in the self-supporting pipe construction method for rehabilitation of the earth.

  In recent years, corrosion caused by hydrogen sulfide has become serious for concrete pipes that are widely used in sewerage projects, and even pipes that have less than their useful lives have problems such as water leakage. As a method for restoring existing pipes that have already been used (pipe rehabilitation method), in addition to exchanging existing pipes by excavation, non-open-cutting pipe rehabilitation methods such as photo-curing method and heat-curing method are used. There is a method of inserting a flexible synthetic resin pipe with a small diameter and injecting a filler such as mortar into the gap between the pipes to integrate it with the existing pipe, but these conventional pipe rehabilitation methods are both labor and cost It was hanging.

  On the other hand, the present inventor first inserts a pressure-resistant synthetic resin tube for underground burial into the existing tube, seals the gap between the tubes only at both ends, and does not bury the filler in the other intermediate portions. A pipe rehabilitation method (self-supporting pipe construction method) is proposed in which there is a gap as it is and the inserted tube itself functions as a rehabilitation pipe (see Patent Document 1). The pipe used for such a self-supporting pipe construction method is required to have a self-supporting property having sufficient pressure resistance even after the existing pipe collapses. In this document, as a rehabilitation pipe suitable for such a self-supporting pipe construction method, a metal reinforcing wire is also spirally attached to the inner surface of the mountain portion of the synthetic resin wall part having a spiral wave shape, and the inner wall is formed on the inner peripheral side of the pipe wall. We have also proposed a synthetic resin pipe for underground use in which a closed space is formed between the pipe wall and the mountain. According to such a tube, it has flexibility, and at the same time, the pressure strength can be increased without impeding flexibility by the metal reinforcing wire.

  However, the underground synthetic resin pipe described in Patent Document 1 has a problem that the pressure resistance decreases as the diameter increases and is difficult to use as a rehabilitation pipe for a self-standing pipe construction method having a relatively large diameter. Since the rehabilitation pipe drawn into the existing pipe from a narrow manhole or the like is required to have high flexibility, it is usually difficult to provide the rehabilitation pipe itself with sufficient pressure resistance. For this reason, in a general pipe rehabilitation method, the existing pipe is completely integrated with a filler such as mortar, thereby maintaining the pressure strength. In the self-supporting pipe construction method, the rehabilitation pipe is required to have a pressure strength having self-supporting properties at the same time as the flexibility described above, and therefore it is very difficult to develop a rehabilitation pipe.

JP 2008-303970 A

  Therefore, in view of the above-mentioned situation, the present invention is to solve the problem of having excellent flexibility and maintaining sufficient pressure resistance even when the caliber is increased, such as a sewer main having a relatively large caliber, etc. It is the point which provides the pressure-resistant synthetic resin pipe for underground burial suitable also as a rehabilitation pipe | tube of this self-supporting pipe construction method.

  As a result of diligent examination in view of the present situation, the present inventor is a known pipe as a pressure-resistant synthetic resin pipe for underground burial having high strength, but a reinforcing convex part is provided on the outer peripheral side of the main body part whose inner surface is substantially flat. Attention was paid to a tube provided in a spiral shape and a metal strip made of a thin metal plate disposed in a spiral shape on the reinforcing convex portion. This pipe is mainly used for water pipes, sewage (drainage) pipes, etc., and has sufficient pressure resistance due to the presence of spiral reinforcing projections with metal strips. However, this flexibility does not have the high flexibility required for rehabilitation pipes drawn into existing pipes from narrow manholes, It has not been used as a rehabilitation tube. The present inventor contradicts the material of the reinforced convex portion, which is an essential component for improving the pressure strength of the underground pressure-resistant synthetic resin pipe, as the material of the portion responsible for the improvement of the original pressure strength, By using a soft resin, the overall flexibility can be remarkably enhanced while maintaining sufficient pressure strength, and it can be suitably used as a rehabilitation pipe for self-standing pipe construction methods such as sewer mains. The invention has been completed.

  That is, the present invention includes a synthetic resin tube wall having a spirally provided reinforcing convex portion on the outer peripheral side of a main body portion whose inner surface is substantially flat, and the reinforcing convex portion of the tube wall is made of a metal thin plate. A pressure-resistant synthetic resin tube for underground burying in which strips are similarly arranged in a spiral shape, wherein the reinforcing convex part having the metal strip is made of low-density polyethylene resin. A resin tube was constructed.

  Here, the metal strip is bent in an approximately L shape in the tube axis direction with an arch portion arranged along the shape of the reinforcing convex portion in a shape protruding to the outside, and the both ends. What consists of a pair of leg part distribute | arranged to the main-body part side is preferable.

  Moreover, it is preferable that the main body portion of the tube wall is made of a low density polyethylene resin.

  Also, the tube itself is inserted into the existing tube, the gap between the existing tube and the inserted tube is sealed only at both ends, and the other intermediate portion is left without any filling material, and there is a gap as it is. What is used for the use as the said pipe | tube (rehabilitation pipe | tube) penetrated in the pipe rehabilitation method which functions as a rehabilitation pipe | tube is a preferable Example.

  The underground pressure-resistant synthetic resin pipe according to the present invention as described above has excellent strength capable of maintaining sufficient pressure-resistant strength even when the diameter is increased, and as a rehabilitation pipe drawn into an existing pipe from a narrow manhole or the like. As a rehabilitating pipe for self-standing pipe construction methods such as a sewer main pipe with a relatively large diameter, it is of course suitable for use as a water pipe or sewage (drainage) pipe. Can also be suitably used. In addition, compared with a conventional synthetic resin pipe having an increased thickness and increased pressure resistance, it is light in weight, has a low material cost, and is excellent in flexibility, so that a pipe excellent in workability can be provided.

The partially broken side view which shows the pressure | voltage resistant synthetic resin pipe | tube for underground burial concerning a typical embodiment of the present invention. Sectional drawing which shows the principal part of the pressure-resistant synthetic resin pipe | tube for underground burying similarly. Explanatory drawing which similarly shows the example which used the pressure-resistant synthetic resin pipe for underground burial as a rehabilitation pipe. Explanatory drawing which shows the principal part of the example used as a rehabilitation pipe | tube.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the underground pressure-resistant synthetic resin pipe 1 according to the present invention has a tube wall made of a synthetic resin in which reinforcing protrusions 3 are spirally provided on the outer peripheral side of a main body 2 whose inner surface is substantially flat. 10 and the reinforcing convex portion 3 of the tube wall 10 has a structure in which a metal strip 4 made of a thin metal plate is similarly arranged in a spiral shape as shown in the enlarged sectional view of FIG. And this invention is characterized by comprising the reinforcement convex part 3 which has the said metal strip 4 from the low density polyethylene resin.

More specifically, a flat strip-shaped synthetic resin band forming the main body portion 2 is sequentially spirally wound while polymerizing both side edge portions, and the downwardly open substantially V-shaped or U-shaped on the outer peripheral surface thereof. Then, the strip-shaped partially molded body having a protruding edge with both open ends projecting in the lateral direction is spirally formed in order by fusing and integrating a metal reinforcing wire to the inner surface of the peak portion. The reinforcing projections 3 are integrally fused on the surface of the main body 2 so that the protruding edges overlap each other. The shape of the reinforcing protrusion 3 is not limited to the above-described substantially V shape, and may be formed into other shapes such as a substantially U shape. In addition, the present invention is not limited to such a molding method. For example, the partially molded body has a structure in which the left laterally outward projecting edge is elongated, and the projecting edge portion is on the tube axis side of the reinforcing projection 3. It is good also as a structure which obstruct | occludes the surrounding opening part and comprises the continuous main-body part 2. FIG.

  The main body portion 2 may have an inner surface formed in a substantially cylindrical shape and have a somewhat uneven waveform. In the present invention, a low density polyethylene resin is used for the reinforcing convex portion 3. The main body 2 is made of a synthetic resin such as polyethylene or polypropylene, such as polyolefin or vinyl chloride, but other synthetic rubber or soft resin may be used. In particular, it is preferable to use a polyethylene resin from the viewpoint of chemical resistance, and more specifically, it is preferable to use a low-density polyethylene resin for the main body 2 as well. Of course, other synthetic resins can be used. If both the main body 2 and the reinforcing projection 3 are made of low-density polyethylene resin, the degree of adhesion between the two can be improved, and the two can be integrally and efficiently extruded without separately molding them.

  As shown in FIG. 2, the metal strip 4 has an arch portion 40 that extends outward and is arranged along the shape of the reinforcing convex portion 3, and both side end portions thereof are substantially L-shaped in the tube axis direction. It is comprised from the thin metal plate provided with a pair of leg part 41 distribute | arranged to the main-body part 2 side. The metal thin plate may be a punching plate having many small holes penetrating the plate surface in addition to the metal plate having no small holes, and the material may be a stainless steel plate, a steel thin plate, or an iron plate. A thin metal plate may be used.

  The metal band plate 4 is preliminarily embedded in the partial molded body that forms the reinforcing convex portion 3, or is fused to the surface of the main body 2 in a state of being attached and integrated on the inner side or the outer side of the partial molded body. The reinforcing convex part 3 is configured. It is preferable that the metal band plate 4 is a laminated metal plate provided with a synthetic resin coating layer on the front and back sides of a thin metal plate, and is then attached and integrated with the partial molded body. Moreover, it is good also considering the metal strip 4 itself which consists of the said laminated metal plate as the reinforcement convex part 3 instead of a partial molded object. The covering layer in the case of using a laminated metal plate is preferably composed of the same material as that of the synthetic resin wall from the viewpoint of adhesion, and is preferably made of a polyolefin resin such as polyethylene resin or polypropylene resin. In particular, if it is made of a low-density polyethylene resin, it can be set to be the same as the partially molded body of the reinforcing convex part 3 and the resin of the main body part 2 and the adhesion degree is improved. It can be configured as the section 3.

  The reinforcing protrusions 3 may be provided in a plurality of rows, and in this case, the metal strip 4 may be provided only in a part of the rows. Further, the pitch of the reinforcing projections 3 is set to be wider than that of a conventional tube having the same structure, and the one having higher flexibility is a preferred embodiment.

  Next, based on FIG.3 and FIG.4, the pipe renovation method using the underground pressure-resistant synthetic resin pipe 1 of this embodiment is demonstrated.

  In this example, the existing pipe 9 which is a sewer main (fume pipe) is provided between the manholes 81 and 82, and a method of rehabilitating this will be described. In addition, the underground pressure-resistant synthetic resin pipe 1 according to the present invention is used for rehabilitation of a branch pipe, a pipe between a household cottage and a sewage main pipe, and other existing pipes in addition to such a main pipe such as a sewer. Of course, it can be widely applied. In order to rehabilitate the existing pipe 9, the underground pressure-resistant synthetic resin pipe 1 is inserted into the existing pipe 9 from one manhole 81 side, and both ends of the gap between the two pipes are prevented from flowing in. Only the pipe opening process for sealing only 91 and 92 is required, and it is not necessary to completely integrate both pipes.

  That is, the other intermediate portion 93 needs to be integrated with the existing pipe 9 and the rehabilitation pipe by filling a filler such as mortar in the conventional construction method. The resin pipe 1 itself has excellent pressure strength, and has sufficient durability to support earth pressure even if the existing pipe 9 is damaged. The buried pressure-resistant synthetic resin pipe 1 itself can function as an independent drain pipe.

  In this example, the end portion is sealed by attaching the socket member 7 as shown in FIG. 4 so that the end portion of the gap can be sealed very easily. The socket member 7 includes a cylindrical portion 70 that is screwed into the outer periphery of the end portion of the underground pressure-resistant synthetic resin tube 1 to close the gap with the existing tube 9, and a flange portion 71 that contacts the end surface 91 a of the existing tube 9. The inner circumferential surface of the cylindrical portion 70 is provided with a thread groove 70b that is screwed into the outer surface of the tube wall of the underground pressure-resistant synthetic resin tube 1. The other end is sealed in a watertight manner by partially filling the gap with a filler. If this socket member 7 is mounted on the manhole side upstream of the drainage, the construction is easy and the penetration into the gap of the drainage can be reliably prevented. According to the self-supporting pipe construction method as in this example, the pipe rehabilitation can be performed only by sealing the end portion using such a socket member 7, which can contribute to shortening the construction period and reducing the cost. By using the pressure-resistant synthetic resin pipe 1 for underground burying as a rehabilitation pipe for the self-supporting pipe construction method, the end portion can be efficiently sealed even in a narrow manhole.

  Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can of course be implemented in various forms without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 Underground pressure proof synthetic resin pipe 2 Body part 3 Reinforcement convex part 4 Metal strip 7 Socket member 9 Existing pipe 10 Tube wall 40 Arch part 41 Leg part 70 Cylindrical part 70b Screw groove 71 Flange part 81 Manhole 91 End part 91a End face 93 Middle part

Claims (4)

A tube wall made of synthetic resin is provided on the outer peripheral side of the main body portion having a substantially flat inner surface, and a reinforcing resin spirally provided on the outer peripheral side, and a metal strip made of a thin metal plate is also spiraled on the reinforcing convex portion of the tube wall. In the underground pressure-resistant synthetic resin pipe arranged in a shape,
A pressure-resistant synthetic resin tube for underground embedment, wherein the reinforcing convex part having the metal strip is made of low-density polyethylene resin.   The metal strip is arched outwardly in the shape of the reinforcing convex portion, and both end portions thereof are bent in a substantially L shape in the tube axis direction to the main body side. The pressure-resistant synthetic resin pipe for underground embedment according to claim 1, comprising a pair of legs disposed on the ground.   The pressure-resistant synthetic resin pipe for underground burying according to claim 1 or 2, wherein the main body portion of the pipe wall is also made of a low-density polyethylene resin.   Insert the pipe into the existing pipe, seal the gap between the existing pipe and the inserted pipe only at both ends, and refill the inserted pipe itself, leaving the other middle part without any filling material and leaving a gap. The pressure-resistant synthetic resin pipe for underground embedment according to any one of claims 1 to 3, which is used for use as the inserted pipe (rehabilitation pipe) in a pipe rehabilitation method that functions as a pipe.

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