JPH08219334A - Synthetic resin pipe - Google Patents

Abstract

(57) [Summary] [Purpose] Friction between a buried pipeline and a pipe, such as a so-called propulsion method, in which the pipeline is unmanned and the pipelines are sequentially inserted without preparing multiple members separately. Provided is a synthetic resin pipe capable of detecting an accurate position of a buried pipeline from the ground without causing a trouble such as disconnection even in a construction method having a large resistance. A synthetic resin pipe formed by sandwiching a conductive wire in the axial direction of the pipe between a synthetic resin pipe main body and a coating layer provided without being fixed to the surface of the pipe main body.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a synthetic resin pipe.

[0002]

2. Description of the Related Art Conventionally, a so-called locating wire made of a conductive wire is attached to a buried pipe, for example, a water supply / sewer pipe, a gas pipe, etc., and buried to repair a damaged portion. When digging back in, a method is known in which an electric current is caused to flow from the surface of the locating wire to generate a magnetic field, and the magnetic field is detected to accurately grasp the buried position of the buried pipe.

For example, in Japanese Utility Model Laid-Open No. 58-178688, a sandwiching member having a holding portion for a covered conductor is formed in an embedded pipe so as to project at an appropriate interval, and the covered conductor is suspended on the holding portion. A buried pipe having a wiring structure is disclosed.

However, in the method of sequentially sandwiching the sandwiching member in the buried pipe, the sandwiching member must be prepared separately from the buried pipe, and due to an error in counting the required quantity, insufficient preparation, etc. This is also a cause of troubles, and when the earth and stone are backfilled, the coated wire is exposed, so earth pressure acts on the coated wire suspended between the sandwiching members and the sandwiching member comes off. There was a problem such as the conductor being torn off.

Further, Japanese Utility Model Laid-Open No. 51-212009 discloses a buried pipe in which a conductor is buried and enclosed in the wall of the buried pipe. However, in the method of embedding and enclosing the conductor wire in the pipe wall of the buried pipe, when connecting the individual pipes to each other, the conductor wire in the pipe wall is taken out to connect the conductor wires of the adjacent pipes, and after connecting, It is necessary to make complicated pipe joints such as repairing broken parts in the pipe wall.If the pipe line is not connected in this way, intermittent pipes for each individual short pipe are buried and enclosed. In the line, the buried position is limited due to the limit of detection from the ground, and when chamfering the ends of the buried pipe for welding, there is an obstacle to the chamfering work.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and its purpose is to excavate the ground unmanned without separately preparing a plurality of members. Detects the exact position of the buried pipeline from the ground without any trouble such as disconnection even in the construction method with large frictional resistance between the buried pipeline and the piping, such as the so-called propulsion method in which the pipelines are sequentially inserted. It is to provide a synthetic resin pipe that can

[0007]

SUMMARY OF THE INVENTION According to the present invention, a conductive wire in the axial direction of a pipe is sandwiched between a synthetic resin pipe body and a coating layer provided on the surface of the pipe body without being fixed. The subject is a synthetic resin tube.

The synthetic resin pipe main body used in the present invention is not particularly limited as long as it is made of an electrically insulating synthetic resin, but especially for water and sewerage of a life line that is piped in a wide area. Examples thereof include vinyl chloride resin pipes, gas and water and sewer polyretylene pipes, polypropylene pipes, polybutene pipes, and fluororesin pipes.

The coating layer is appropriately selected and used according to the type of synthetic resin used in the synthetic resin tube body, and is not particularly limited, but for example,
When forming a coating layer while sandwiching an electrically conductive lead wire in the axial direction of the pipe body at the same time as molding the synthetic resin pipe body using a crosshead extruder, when forming a coating layer with the polarities of the synthetic resin pipe body, A different synthetic resin may be used, or a coating layer may be provided on the surface of the synthetic resin tube body with a releasable layer interposed.

As a combination of the synthetic resins having different polarities, for example, a tube body made of vinyl chloride resin is coated with a coating layer made of low-density, medium-density or high-density polyethylene, or made of medium-density or high-density polyethylene. A coating layer made of a plasticized vinyl chloride resin may be used for the tube body.

The method and form of forming the above-mentioned coating layer are as follows:
It is also related to the embedding method, and the optimum method may be adopted depending on the embedding method and is not particularly limited. For example, a coating layer using a crosshead extruder or the like at the same time as molding of the synthetic resin pipe body. May be molded, or the coating layer may be molded on the molded pipe body using a crosshead extruder or the like, and the molded coating layer may be formed on the molded pipe body with an adhesive or various It may be coated with a fastener, the joint portion of the molded coating layer may be welded and coated on the molded tube body, and the tubular coating layer having elasticity may be applied to the molded tube body as a lubricant. May be coated using
Alternatively, the molded tube body may be covered with a shrinkable tubular coating layer and then shrunk by an appropriate method such as heat to cover the tube body.

As the molded coating layer, for example, a shrinkable or non-shrinkable film or sheet of plasticized vinyl chloride resin, hard vinyl chloride resin, low density, medium density or high density polyethylene, polypropylene, polybutene, etc. It is preferably used.

As the above-mentioned fastener, for example, a high-density polyethylene sheet is coated on the tube body so as to be wrapped from both side edges in the radial direction of the tube body, and one end located under the high-density polyethylene sheet as shown in FIG. One or a plurality of grooves (two in FIG. 2) having an undercut portion in the axial direction of the pipe body are provided on the upper surface near the edge,
In addition, a ridge having a locking portion corresponding to the groove is provided on the lower surface near the other edge overlapped with this, and the ridge is fitted and fixed to the groove with or without an adhesive. However, a form in which a coating layer of a high-density polyethylene sheet is provided on the tube body may be used.

Further, as shown in FIG. 3, instead of the groove and the ridge, a high-density polyethylene sheet coated so as to wrap the positions where the groove and the ridge are provided from both side edges in the radial direction of the pipe body. It is also possible to have the both end edges faced against each other.

Further, instead of the groove and the ridge shown in FIG. 2, the high-density polyethylene sheet covered in FIG. 4 so as to wrap from the both side edges in the radial direction of the pipe main body is shown in FIG. In this embodiment, a connecting portion such as a magic tape (registered trademark) or a pressure-sensitive adhesive layer is provided, and the covering layer is provided by pressing the connecting portion from above the covered high-density polyethylene sheet. May be.

The joints shown in FIGS. 2 to 4 may be used as they are without any particular protection, but the joints may be jointed together at the left and right edges. The sheet may be attached with an adhesive tape or the like to reinforce the joint.

The conductive wire in the present invention is not particularly limited as long as it has high conductivity and appropriate mechanical strength, but is made of a conductive material such as copper and its alloys, aluminum. Examples include a single wire, a plurality of parallel single wires, a stranded wire, a film-like or plate-like body, and the like. The conductor may be reinforced by using glass fiber or the like surface-treated with an insulator together, or the conductor may be used as it is without being particularly protected. May be used as a coated wire covered with an insulator.

The conductor may have only one strip in the axial direction of the tube body, and the strip may be sandwiched between the tube body and the coating layer, but a plurality of strips are arranged at appropriate intervals in the radial direction of the tube body. It may be sandwiched.

The joining of the synthetic resin pipes of the present invention is not particularly limited, and the sleeve joining method and the screw joining method conventionally used for synthetic resin pipes, for example, with or without a joint are used. The butt fusion bonding method may be used, and the sleeve joining method may be either an adhesive method or a fusion bonding method. In particular, the so-called butt fusion welding method, in which pipe ends are fused without using a joint, produces almost no step at the joint portion, and is therefore most preferable as a pipe joining method used in the propulsion method.

In the above joining, since the coating layer forming the surface layer of the synthetic resin pipe is not fixed to the pipe body, the unnecessary portion of the coating layer is cut with a simple cutting tool such as a cutter knife, Part of the conductor may be peeled off to expose the conductor wire, and the pipe body may be joined to the conductor wire. At the time of the above-mentioned joining, EF for performing fusion-bonding by a heating wire built in the joining
It is more convenient to use an (Electro Fusion) joint.

[0021]

The synthetic resin pipe of the present invention comprises a conductive wire in the axial direction of the pipe sandwiched between the synthetic resin pipe main body and the coating layer provided on the surface of the pipe main body without being fixed. Therefore, since the synthetic resin pipe body is not provided with extra protrusions and the exposed surface is smooth, a special device is required even for the propulsion method in which the burying pipe is inserted between the earth and stone with large friction resistance. According to the conventional method, the synthetic resin pipe can be buried very smoothly without damaging the conductor wire or the coating layer without using it at all.

Further, in the synthetic resin pipe of the present invention, when the pipe bodies are joined to each other, unnecessary portions of the coating layer can be cut with a simple cutting tool such as a cutter knife, or part of the coating layer can be peeled off to expose the conductive wire. The joining method conventionally used for synthetic resin pipes can be used as it is.

[0023]

Embodiments of the present invention will be described below.

Example 1 A 0.5 mmφ copper wire 10 prepared separately is provided on the surface of a polyethylene pipe for gas having a nominal diameter of 100.
Using a crosshead extruder, insert a flat wire with a thickness of 2 mm, which is made by coating a book with medium-density polyethylene, into the pipe axial direction from three locations at equal intervals in the radial direction of the pipe.
A cylindrical coating layer made of a plasticized vinyl chloride resin having a thickness of μm was adhered to form a synthetic resin tube.

(Embodiment 2) A copper wire 10 of 0.5 mmφ is separately provided on the surface of a hard vinyl chloride resin pipe for waterworks with a nominal diameter of 100.
A flat electric wire with a thickness of 2 mm coated with plasticized vinyl chloride resin is inserted into the pipe axially from three locations at equal intervals in the radial direction of the pipe, and a thickness of 5 is obtained using a crosshead extruder or the like.
A cylindrical coating layer made of 0 μm medium density polyethylene was adhered to form a synthetic resin tube.

(Embodiment 3) FIG. 2 shows both sides of a high-density polyethylene sheet 2 in which the surface of the gas polyethylene pipe of Embodiment 1 is covered so as to be wrapped from both side edges in the radial direction of the pipe body 1 prepared separately. FIG. 4 is a partially cutaway perspective view showing a main part of a joined state of edges. Reference numerals 21 and 21 are provided with two grooves having an undercut portion in the axial direction of the pipe main body on the upper surface near the one end edge 2a on the lower side of the high-density polyethylene sheet 2, and are superposed on this groove. A ridge 2 having a locking portion corresponding to the groove on the lower surface near the other end edge 2b
2 and 22 are provided, the ridge 22 is fitted and fixed to the groove 21 by using an adhesive, and the coating layer 2 of the high-density polyethylene sheet is provided on the tube body 1 as in Example 1. A synthetic resin tube was prepared.

(Embodiment 4) FIG. 3 is a partially cutaway sectional view showing a main portion of both sides of the high-density polyethylene sheet 2 in a joined state. The groove 21 and the ridge shown in Example 3 on both side edges of the high-density polyethylene sheet 2 in which the surface of the gas polyethylene tube of Example 1 is covered so as to be wrapped from both side edges in the radial direction of the separately prepared tube body 1. 22
In place of the above, the abutting side edge surfaces 2 of the high-density polyethylene sheet covered so as to wrap the positions where the grooves 23 and the protrusions 24 are provided from the both side edges in the radial direction of the pipe body.
A synthetic resin tube similar to that of Example 1 was produced except that the resin was changed to c and 2d.

(Embodiment 5) FIG. 4 is a partially cutaway cross-sectional view showing a main portion of both side edges of the high-density polyethylene sheet 2 in a joined state. The groove 21 and the ridge shown in Example 3 on both side edges of the high-density polyethylene sheet 2 in which the surface of the gas polyethylene tube of Example 1 is covered so as to be wrapped from both side edges in the radial direction of the separately prepared tube body 1. 22
In place of the high-density polyethylene sheet, velcro tapes 25 and 26 are adhered and fixed along the overlapping upper and lower edges of the high-density polyethylene sheet.
A synthetic resin pipe similar to that of Example 1 was produced except that the coating layer 2 was provided by being pressed from above to be in close contact with the pipe body 1.

Using the synthetic resin pipes of the present invention obtained in the above examples, the propulsion method was used to join polyethylene pipes for gas to each other by the butt welding process, and the hard vinyl chloride pipes for waterworks were glued to each other. It was piped and buried by the sleeve joining method used.

Each of the synthetic resin pipes of the present invention obtained in the above examples comprises a synthetic resin pipe main body and a coating layer provided on the surface of the synthetic resin pipe main body without fixing the conductive wire in the axial direction of the pipe. Since it is sandwiched between them, the synthetic resin pipe main body is not provided with extra protrusions and the exposed surface is smooth, so the synthetic resin pipe is extremely smooth without damaging the conductor wire or coating layer. Could be buried.

Further, when joining the pipe main bodies to each other, unnecessary portions of the coating layer can be cut with a simple cutting tool such as a cutter knife or a part of them can be peeled off to expose the conductor wire, so that it has been used in conventional synthetic resin pipes. The joining method used is still available.

Further, the embedded position of the synthetic resin pipe 1 can be accurately grasped by applying a current to both ends of the conductor 3 piped as described above and detecting the magnetic field generated thereby.

[0033]

Since the synthetic resin pipe of the present invention is constructed as described above, no special device is used at all in the propulsion method in which the synthetic resin pipe is inserted between the earth and stone having a large friction resistance. According to the conventional method, the synthetic resin pipe can be embedded extremely smoothly without damaging the conducting wire or the coating layer.

In addition, in the synthetic resin pipe of the present invention, when the pipe bodies are joined to each other, unnecessary portions of the coating layer can be cut with a simple cutting tool such as a cutter knife, or part thereof can be peeled off to expose the conductor wire. The joining method conventionally used for synthetic resin pipes can be used as it is.

[0035]

[Brief description of drawings]

FIG. 1 is a perspective view showing an overall configuration of a synthetic resin pipe of the present invention.

FIG. 2 is a partially cutaway perspective view showing a main part of a jointed state of both side edges of a coating layer showing another example of the embodiment of the synthetic resin pipe of the present invention.

FIG. 3 is a partially cutaway cross-sectional view showing a main part of a jointed state of both side edges of a coating layer showing another example of the embodiment of the synthetic resin pipe of the present invention.

FIG. 4 is a partially cutaway cross-sectional view showing a main part of a jointed state of both side edges of a coating layer showing another example of the embodiment of the synthetic resin pipe of the present invention.

[Explanation of symbols]

 1 synthetic resin pipe 2 coating layers 2a, 2c near one end edge of the coating layer 2b: 2d near the other end edge of the coating layer 21, 24 groove 22, 23 ridge 25:26 magic tape 3 conductor wire

Claims (1)

[Claims] 1. A synthetic resin pipe, wherein a conductive wire, which is electrically conductive in the axial direction of the pipe, is sandwiched between a synthetic resin pipe main body and a coating layer provided without being fixed to the surface of the pipe main body.