JP4383414B2 - Conduction method of buried pipeline - Google Patents

Description

  The present invention relates to a conduction method for a buried pipeline.

  In many cases, pipes constituting water pipes are buried in the ground after a plurality of cast iron pipes having pipe joints having an insertion structure are joined to each other. The pipes buried in the ground in this way may be laid in places where stray currents are generated, such as in the vicinity of train tracks or near substations. In that case, it is necessary to energize the pipe for the purpose of preventing corrosion of the cast iron pipe due to stray current (for example, Patent Document 1).

  4 and 5 show a conventional conduction method for this purpose. In FIG. 4, reference numeral 1 denotes a pipe line buried in the ground, in which a plurality of cast iron pipe bodies 2 are joined together. Each tubular body has a receiving port 3 at one end and an insertion port 4 at the other end, and the insertion port 4 of one tubular body is inserted into the receiving port 3 of the other tubular body. The bodies are joined together. Between the inner peripheral surface of the receiving port 3 and the outer peripheral surface of the insertion port 4, an annular seal material made of rubber is arranged, so that the electrical continuity between the adjacent tubular bodies 2 and 2 is established. There is concern that it will be insufficient. Then, the conduction | electrical_connection state is ensured by passing the bond wire 5 between these tubular bodies 2 and 2. As shown in FIG. And it is comprised so that the stray current may be drained about the whole pipe line 1 by electrically connecting the drain line to the ground surface to one of the pipe bodies.

  FIG. 5 shows a joint structure between the bond line 5 and the tube body 2. As shown in the figure, a conducting plate 6 made of, for example, rectangular steel as a terminal is welded to the entire surface of the cast iron tube 2 so that the conducting plate 6 is electrically connected to the tube 2. It is fixed. The terminal 7 is electrically connected to the end of the bond wire 5, and the terminal 7 is welded to the conductive plate 6 by, for example, thermite welding, so that the bond wire 5 and the conductive plate 6 are fixed. 5 and the conductive plate 6, that is, the tube body 2 are electrically connected.

With the above configuration, the conductive plates 6 and 6 are provided as terminals on the receiving port 3 side and the insertion port 4 side of the tubes 2 and 2, respectively, and when the receiving port 3 and the insertion port 4 are joined. The conductive plates 6 and 6 are connected to each other by the bond wire 5, thereby electrically connecting the electrically insulative joint portion with the bond wire 5 as a conductive wire, and using the tube body 2 itself as a conductor. The entire conduit 1 can be electrically connected. Therefore, even when a current leaked from, for example, an electric railway track flows in any part of the pipeline 1, the entire pipeline 1 is in a conductive state, so that the current can be guided to a predetermined drainage portion. it can.
JP-A-5-230677

  However, since the pipe body 2 itself constituting the pipe line 1 is used as a conductor in the above-described configuration, each pipe body 2 has at least the receiving port 3 side at both ends thereof. Conductive plates 6 as terminals must be provided at two locations on the side of the insertion opening 4 side.

  Moreover, after joining the receiving port 3 and the insertion port 4, the welding work in the pipe | laying site is needed, and it takes time and construction work. Moreover, a high level of skill is required for on-site thermite welding. For this reason, the construction period becomes longer and the construction cost also increases. In addition, since the conductive plate 6 is welded to the pipe body 2 at the piping site and the terminal 7 is connected to the conductive plate 6 by thermite welding, anticorrosion coating on the outer surface of the pipe body 2 is performed as a pretreatment for welding. Troublesome work, such as the need to remove with a grinder or the like. If such pretreatment is not performed sufficiently, poor welding occurs and reliable connection becomes difficult.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve such a problem and to enable the pipes to be conducted in a short time and with simple work.

  In order to achieve this object, the present invention provides a conduction method for a buried pipeline in which a plurality of cast iron pipes having a pipe joint having a receiving structure are joined to each other, and an electric wire along the buried pipeline. The terminal is electrically connected to the electric wire, and the terminal is electrically connected to the tubular body by a bolt.

  According to the present invention, in the above, by connecting the terminal connected to the electric wire with a bolt at one place for each tubular body, the electric wire arranged along the buried pipeline and each tubular body, Are preferably electrically connected.

  Therefore, according to the present invention, since it is only necessary to electrically connect the terminals to the respective pipes with bolts, the connection work of the terminals to the pipes can be completed easily and in a short time. In the case where a stray current occurs in the ground, when the current flows into the pipeline, this current can be caused to flow from the tube body to the electric wire and be guided to a predetermined exhaust position. Alternatively, the stray current can be guided to the discharge position through the electric wire without flowing into the pipeline.

  Moreover, according to this invention, the whole pipe line can be made into a conduction | electrical_connection state only by electrically connecting the terminal connected to the electric wire with a volt | bolt in one place for every tubular body.

  In FIG. 1, 11 is one pipe body joined together, 12 is the other pipe body, and these pipe bodies 11 and 12 are made of ductile cast iron. A receiving port 13 is formed at the end of the tube 11, and an insertion port 14 to be inserted into the receiving port 13 is formed at the end of the tube 12. A tapered sealing material pressure contact surface 15 is formed on the inner periphery of the opening end of the receiving port 13, and an annular lock ring receiving groove 16 is formed on the inner periphery of the receiving port 13 on the inner side of the sealing material pressure contacting surface 15. Is formed. A rear end surface 17 in the tube radial direction is formed inside the receiving port 13 that is spaced from the lock ring housing groove 16 to the rear side.

  An annular rubber sealing material 18 is disposed between the sealing material pressure contact surface 15 and the outer peripheral surface of the insertion opening 14. A backup ring 19 is provided on the back side of the receiving port 13 with respect to the sealing material 18, and a lock rig 20 is provided on the back side of the receiving port 13 with respect to the backup ring 19 in a state of being accommodated in the groove 16. . An annular protrusion 21 is integrally formed on the outer periphery of the distal end of the insertion opening 14, and the annular protrusion 21 is configured to be positioned between the lock ring 20 and the back end surface 17.

  The lock ring 20 is configured to have a diameter reducing force, and allows passage of the annular protrusion 21 while being forcibly expanded when the insertion opening 14 is inserted into the receiving opening 13. After passing, the forcible force is released to reduce the diameter so that it can be attached to the outer periphery of the insertion port 14 and contact the annular protrusion 21, thereby preventing the insertion port 14 from being detached from the receiving port 13. It is. The annular protrusion 21 of the insertion opening 14 is movable in the tube axis direction between the lock ring 20 and the back end face 17, thereby providing an expansion / contraction function between the receiving opening 13 and the insertion opening 14. By these, the illustrated pipe joint can function as an earthquake-resistant joint.

  A split ring 22 that contacts the sealing material 18 and a push ring 23 that contacts the split ring 22 are fitted on the outer periphery of the insertion slot 14 outside the receiving port 13. At the end of the receiving port 3, metal bolts 24 in the tube axis direction are implanted at a plurality of positions along the tube circumferential direction. Reference numeral 25 denotes a metal nut that can be fastened to the receiving port 13 by being screwed together with the bolt 24, thereby compressing the sealing material 18 via the split ring 22, thereby inserting the receiving port. It is possible to exhibit the required sealing performance between the mouths.

  The crimp terminal 27 is fastened together with the pusher wheel 23 by the bolt 24 and the nut 25. The crimp terminal 27 is formed in an L shape as shown in FIGS. 1 and 2, and integrally includes a joint fastening portion 28 in the tube diameter direction and an electric wire crimp portion 29 in the tube axis direction. The electric wire crimping portion 29 is disposed so as to be exposed outward in the tube radial direction at a position outside the bolt 24 along the tube radial direction.

  An electric wire 31 is disposed along the buried conduit 10 constituted by the plurality of tubular bodies 11 and 12. The electric wire 31 is crimped to the electric wire crimping portion 29 of the crimp terminal 27 at the position of the receptacle 13 of each tubular body. That is, the electric wire 31 is electrically connected to the receptacle 13 via the crimp terminal 27, the nut 25, and the bolt 24 at the receptacle 13 of each tubular body. The state of this electrical connection is schematically shown in FIG.

  The buried conduit 10 constituted by the plurality of tubular bodies 11 and 12, including the electric wires 31, is covered with a resin sleeve 32 for preventing corrosion of the tubular bodies 11 and 12. A rubber band 33 is used to fasten the resin sleeve 32 and the electric wire 31 to the tubular bodies 11 and 12. As illustrated, the electric wire 31 is disposed along the pipe line 10 in a slack state and is fastened to the pipe bodies 11 and 12 by the rubber band 33.

  With such a configuration, the tubular body 11 is electrically connected to the electric wire 31 by the crimp terminal 27, whereby each tubular body is electrically connected to the electric wire 31 over the length direction of the conduit 10. The stray current can be discharged. Moreover, the current flowing into the pipe line 10 can be drained only by conducting the electrical connection to the electric wire 31 by the crimp terminal 27 at one place for each tubular body. Therefore, it is not necessary to use the pipe line itself as a conductive path for discharging, and therefore, there is an advantage that it is not necessary to electrically connect the ends of the pipe bodies 11 and 12. In addition, by covering the tubular bodies 11 and 12 with the resin sleeve 32, the stray current can be prevented from entering the conduit 10 at a considerable rate.

  In the construction work, a special skill such as welding is required by simply connecting the electric wire 31 to the crimping terminal 27 and fastening the crimping terminal 27 to the press ring 23 together with the nut 25 and the bolt 24. The electric wire 31 and the pipe body 11 can be easily conducted without this. As a result, it is possible to reduce the construction time and the construction cost. Further, the welding work at the site where the pipe is laid is easily influenced by conditions such as the weather, but according to the above, there is an advantage that the concern about this point can be eliminated.

  As described above, the joint formed by the receiving port 13 and the insertion port 14 has a seismic function and can be expanded and contracted. However, the electric wire 31 is disposed in a slack state, and a resin sleeve after wiring work. Since it is covered with 32, the disconnection of the electric wire by expansion and contraction of the joint can be effectively prevented.

  In the above description, the pipe joint having the structure shown in FIG. 1 and having the crimp terminal 27 connected to the receiving port 14 has been described as an example. However, the structure of the joint and the connection part of the crimp terminal are illustrated. Not limited to those. The present invention is characterized in that a terminal electrically connected to an electric wire is electrically connected to a tubular body by a bolt, and any tubular body and pipe joint having an insertion structure that can make use of this characteristic. It is applicable to.

  For example, instead of the crimp terminal 27 that is fastened together with the above-described push ring 23, a metal plate having a screw hole is welded to the pipe body, for example, at a pipe body manufacturing factory, and this pipe is used on the pipe construction site. It is also possible to just screw the terminal.

  Moreover, although the example which has arrange | positioned the one electric wire 31 along the pipe line 10 in the above was demonstrated, you may arrange | position a some electric wire in consideration of safety | security. Furthermore, the electric wire 31 and each pipe | tube can also be joined in several places.

It is sectional drawing which shows the conduction | electrical_connection method of the buried pipe line of embodiment of this invention. It is a perspective view of the crimp terminal in FIG. It is a schematic diagram which shows the mode of the electrical connection of the part shown in FIG. It is a figure which shows the conduction | electrical_connection method of the conventional buried pipe line. FIG. 5 is a detailed view illustrating a configuration of a main part in FIG. 4.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Buried pipe 11 Tube 12 Tube 13 Receiving port 14 Inserting port 24 Bolt 25 Nut 27 Crimp terminal 31 Electric wire

Claims (2)

  A conduction method for a buried pipeline in which a plurality of cast iron pipes having a pipe joint having a receiving structure are joined to each other, wherein an electric wire is arranged along the buried pipeline, and a terminal is electrically connected to the electric wire. And connecting the terminal electrically to the pipe body with a bolt.   It is characterized in that the electric wires arranged along the buried pipeline and the respective pipes are electrically connected by electrically connecting the terminals connected to the electric wires with bolts at one place for each tubular body. The conduction method of the buried pipeline according to claim 1.

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