JP2011258529A - Grounding electrode of grounding resistance reducer injection method and grounding construction method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a grounding electrode of a grounding resistance reducer injection method which can achieve efficient renovation construction by making it unnecessary to dig around a grounding electrode burial site for grounding renovation construction in the future, and to provide a grounding construction method using the same.SOLUTION: In an installation construction method using a grounding electrode of a grounding resistance reducer injection method, the grounding electrode comprises a pipe material whose tip is closed by a closing member having a conical outer shape and whose base end is conductive to an opening end; a coupling cylinder of electric insulation whose one end can be coupled to the opening of the base end part directly or indirectly with a coupling part between them and which has a openable and closable lid part on the base end side. A rod body pressing surface, which is pressed by a rod body inserted in the pipe material, is formed in the pipe material closer to the tip, multiple open holes, which penetrate inside and outside the vicinity base end side of the rod body pressing surface, are positioned in the peripheral side surface, and a grounding line connection terminal is provided closer to the base end part. Preferably, the size of the cross section of the rod body orthogonal to the axial direction is made slightly smaller than the inner diameter of the pipe material.

Description

  The present invention relates to a grounding resistance reducing agent-injection-type grounding electrode capable of improving the efficiency of renovation work and a grounding work method using the same.

  In distribution lines, it is obliged to ground the power poles for the security of the power system. The grounding work is usually performed by burying a metal grounding pole at the base of the utility pole or in the vicinity thereof. Conventionally, as this grounding electrode, a grounding plate such as a copper plate or a copper-clad steel plate or a grounding rod such as a copper rod, a copper-clad steel rod, or a galvanized steel rod has been used. A grounding resistance reducing agent injection type grounding electrode made of a pipe material has also been used. This grounding resistance reducing agent-injection type grounding electrode is a tube material having a conical blocking member at the tip, a through-hole penetrating the inside and outside of the tube wall, and an opening at the base end side. When placing inside, a grounding resistance reducing agent is injected into the pipe material and ejected from the through hole to reduce the grounding resistance value of the soil around the placement position, and then ground the opening on the base end side It is made to close with the line connection terminal. Several proposals have been made regarding such a ground resistance reducing agent-injection-type ground electrode (see, for example, Patent Document 1).

  It has been found that the grounding resistance value of the grounding electrode, including the grounding resistance reducing agent injection type grounding electrode, generally increases with the passage of time and exceeds the specified value. For this reason, it is necessary to periodically measure and monitor the transition of the ground resistance value, and to carry out refurbishment work in advance to reduce the ground resistance value of the ground electrode that may exceed the specified value.

  This renovation work is usually performed in the following procedure. When the grounding electrode is a grounding rod, a position separated from the existing grounding rod by a predetermined distance in the horizontal direction (usually about 1 m or more) is excavated, and an additional grounding rod is placed there. Then, these two grounding rods are connected by a grounding wire, and after confirming that the grounding resistance value satisfies the regulation, the excavation position is backfilled. In addition, in the case of a grounding resistance reducing agent injection type grounding electrode, excavate the position where the grounding electrode is buried, remove the ground wire connection terminal on the base end side of the pipe material, inject the grounding resistance reducing agent again, After confirming that the resistance value satisfies the specified value, it is constructed through each step of refilling its position.

  However, in the case of the ground resistance reducing agent injection type ground electrode, even if the ground resistance reducing agent is injected, the effect of reducing the ground resistance by the agent may not be obtained, and the ground resistance value may not become a specified value or less. In such a case, further excavate a position spaced apart from the grounding electrode by a predetermined distance in the horizontal direction, and newly bury a grounding rod, a grounding resistance reducing agent-injected grounding electrode, etc. It is necessary to connect a ground wire between them.

  Since the frequency of such renovation work is very high and excavation is always necessary, a great deal of labor and cost is required for each renovation work. In addition, if the excavation location is within public land, an application is required, and if it is within private land, the landowner must obtain the consent, especially in private houses that are private land. In some cases, excavation permission may not be obtained.

Utility Model Registration No. 3029443 Specification

  In view of the above circumstances, the present invention eliminates the need for excavation around the position where the ground electrode is buried during future ground repair work, thereby improving the efficiency of the repair work. And it aims at providing the ground construction method using this.

  The inventors of the present invention have made extensive studies on the necessity of excavation during renovation work by exposing the base end side of the ground resistance reducing agent-injected grounding electrode to the ground. In particular, the cause of the problem that the measured value of the grounding resistance does not fall below the specified value even when the grounding resistance reducing agent is injected has been pursued. As a result, immediately after placing the grounding resistance reducing agent injection type grounding electrode and injecting the grounding resistance reducing agent, earth and sand often enter from the through-hole drilled in the tube wall, and the grounding resistance is reduced. As a result of the agent being hardened in the state of taking in the earth and sand and the through hole being closed, it was found that even when the ground resistance reducing agent was injected, it was not ejected outside the tube of the ground electrode.

  Therefore, according to one aspect of the present invention, the object is that the distal end is closed by a conical member having a conical outer shape, and the proximal end is an open end, a conductive tube, and the opening of the proximal end. One end of which is connectable directly or indirectly via a connecting portion, and has an electrically insulating connecting cylinder having a lid that can be opened and closed on the base end side thereof, and the tube material is located closer to the tip in the tube material. A rod body pressing surface that is pressed by a rod body inserted therein is formed, and a plurality of through-holes penetrating inward and outward are disposed on the peripheral side near the proximal end side of the rod body pressing surface and closer to the proximal end portion This is achieved by a grounding resistance reducing agent-injected grounding electrode characterized in that a grounding wire connecting terminal is provided on the grounding electrode.

  According to another aspect of the present invention, the object is to provide a conductive tube having a distal end closed by a conical member having a conical outer shape and having an opening at a proximal end, and a lid that can be opened and closed at one end. A grounding construction method using a grounding resistance reducing agent injection type grounding electrode including an electrically insulating connecting cylinder having a step of drilling a pilot hole in the ground, and inserting a rod into the pipe, A step of driving the ground electrode into the pilot hole by transmitting a downward external force to the body pressing surface; a step of injecting or flowing a ground resistance reducing agent into the conductive tube; and a base end of the ground electrode Connecting the end opposite to the end having the lid portion of the connecting cylinder directly to the opening on the side or indirectly through the connecting portion. Is done.

  In the present invention, an electrically insulating connecting cylinder is connected to the upper end opening of the ground resistance reducing agent injection type grounding electrode so as to communicate with the ground, and a lid that can be opened and closed is provided on the ground side of the connecting cylinder. In the repair work, the lid is opened so that the ground resistance reducing agent can be injected, so that excavation is not required in the repair work for the ground electrode. In addition, the grounding resistance reducing agent injection type grounding electrode of the present invention has a plurality of through holes for allowing the grounding resistance reducing agent to flow out close to the closing member of the pipe material, and a rod is inserted into the conductive pipe material when it is placed. Since the grounding resistance reducing agent-injection type grounding electrode of the present invention is driven into the ground by pressing the mandrel pressing surface formed on the closing member at the tip, the penetration formed near the closing member of the pipe Intrusion of earth and sand from the hole can be suppressed.

It is a figure which shows an example of embodiment of the ground resistance reducing agent injection | pouring type ground electrode of this invention. It is a figure for demonstrating an example of the grounding construction method using embodiment shown in FIG. It is a figure which shows another example of the use condition of embodiment shown in FIG.

  Hereinafter, embodiments of the ground resistance reducing agent-injected grounding electrode of the present invention will be described in more detail with reference to the accompanying drawings. FIG. 1 shows an example of an embodiment of a ground resistance reducing agent injection type ground electrode (hereinafter simply referred to as a ground electrode) of the present invention. In the embodiment shown in this figure, the grounding electrode of the present invention has a hook-shaped closing member 11 at one end, and is connected to a conductive tube 10 having an opening at the other end via connectors 14 and 17. And an electrically insulating connecting cylinder 16. In the following, for convenience of explanation, instead of “one end” and “the other end” of the pipe member 10 and the connecting cylinder 16, they are referred to as “an upper end” and “a lower end”, respectively, in the drawing.

  The conductive tube material 10 is not particularly limited with respect to the shape and size of the cross section in the direction orthogonal to the tube axis direction, and the total length in the direction, and is a conventionally known tubular grounding electrode, or an inner diameter and a wall substantially similar to this. A metal tube having a thickness can be suitably used. A plurality of through holes 13, 13,... Penetrating into and out of the pipe are regularly arranged at the end of the metal pipe member 10 near the closing member 11. The diameter and the number of the through holes 13 may be appropriately determined in consideration of the injection amount of the grounding resistance reducing agent injected into the pipe member 10 and the injection pressure when the agent is injected from the through hole. it can.

  The conductive tube material 10 can be appropriately selected from conventionally known metal or conductive ceramic tube materials. Examples of the metal pipe material include metals conventionally used for grounding electrodes such as galvanized pipes, thick steel electric wire pipes, and stainless steel pipes. Among these, since the pipe material 10 is buried in the ground for a long period of time, it is particularly preferable to use a stainless steel pipe or the like excellent in corrosion resistance. Examples of the conductive ceramic include alumina-titanium carbide type and conductive zirconia type.

  The closing member 11 has a conical outer shape and is provided at the lower end portion of the tube material 10. In this embodiment, the closing member 11 is solid and does not have a hollow portion, but may have a structure having a hollow portion. The blocking member 11 has an end surface 11 a (hereinafter referred to as a rod pressing surface) that is substantially orthogonal to the tube axis direction of the tube material 10 toward the tube material 10. As will be described later, the rod body pressing surface 11a has a downward external force applied to a rod body (not shown; see reference numeral 23 in FIG. 2) inserted into the tube material 10 from the upper end side through the rod body 23. This is transmitted to the body pressing surface 11a, whereby the ground electrode 1 of the present invention is driven into the ground.

  The material of the closing member 11 is not particularly limited as long as it has conductivity. However, since it is buried in the ground for a long time, it is formed of a material having excellent corrosion resistance, such as stainless steel, like the tube material 10. It is preferable that The closing member 11 can be fixed to the pipe member 10 by a known fixing method such as welding, or can be formed into a conical shape by cutting the tip of a solid rod body hollowed out into a tubular shape.

  A connecting portion 14 is externally fitted to the upper end of the tube 10. The connecting portion 14 may be formed of any material that is conductive or electrically insulating. Examples of the conductive material include those exemplified above for use in the tube material 10. Examples of the electrically insulating material include various synthetic resins such as hard vinyl, and among them, those having excellent corrosion resistance are preferable.

  A lead terminal 20 protrudes from the outer peripheral surface of the connecting portion 14, and a ground wire 21 is connected to the lead terminal 20. The lead terminal 20 is electrically connected to the tube material 10. Connected to the lead terminal 20 is a ground wire pulled down from the utility pole or a ground wire communicating with an existing ground electrode.

  As long as the connecting tube 16 is a tube material that exhibits electrical insulation, the shape and size of the cross section in the direction orthogonal to the tube axis direction are not particularly limited, and are appropriately selected from known ones. However, it is preferable to use a tube material having the same cross-sectional shape as the tube material 10 and having substantially the same inner diameter. For such a connecting tube 16, for example, an electrically insulating synthetic resin tube such as a hard vinyl tube can be suitably used.

  In the present embodiment shown in FIG. 1, a connecting portion 17 that can be connected to the connecting portion 14 at the upper end portion of the pipe member 10 is provided on the lower end side of the connecting tube 16. Similarly to the connecting portion 14, the connecting portion 17 is also fitted and fixed to the lower end portion of the connecting tube 16. The connecting portion 17 may be formed of any of the exemplified conductive and electrically insulating materials. In the present embodiment, the connecting portion 14 and the connecting portion 17 are formed as separate bodies in this way, but are not limited to being separate bodies, and when these are made of the same material. May be integrally formed.

  An openable / closable lid 19 is provided at the upper end of the connecting cylinder 16. When the grounding work is performed using the grounding electrode of the present embodiment, the lid 19 is disposed at a predetermined height or on the ground from the ground and exposed to traffic, traffic, and the like. It is preferable that the upper end of the head is made robust. Further, as shown in FIG. 1, an enlarged diameter portion 18 can be provided in the upper region of the connecting cylinder 16. Although this enlarged diameter portion 18 is not an essential configuration, the provision of the enlarged diameter portion 18 has an advantage that the convenience of work can be expected to be improved in the future repair work for the ground electrode of the present invention.

  Next, a grounding method using the grounding electrode of the present invention will be described. FIG. 2 is a diagram for explaining a grounding method using the grounding electrode of the present invention. As shown in FIG. 1 (a), first, a pilot hole is opened using a suitable tool at the position where the ground electrode is to be placed. The diameter and depth of the pilot hole can be set as appropriate according to technical standards to be followed by the worker of the grounding work (for example, the diameter of the pilot hole is about 35 mm and the depth is about 1 m).

  Next, a rod body (hereinafter referred to as a mandrel) 23 is inserted from the opening at the upper end of the ground electrode 1, and an external force is applied downward thereto to drive the ground electrode 1 into the prepared hole (see FIG. 2 (b)). It is preferable that the outer diameter of the mandrel 23 is set to be slightly smaller than the inner diameter of the tube material 10 at least on the lower end side. At this time, the external force applied downward acts on the rod pressing surface 11a (see FIG. 1) via the mandrel 23.

  When the connecting portion 14 of the ground electrode 1 of the present invention is exposed from the ground, the ground wire 21 is connected to the lead terminal 20, and then the ground electrode 1 is further driven into the ground by the same method. When the upper end of the connecting portion 14 of the tube material 10 reaches a predetermined depth, the mandrel 23 is pulled out from the tube material 10 and the connecting tube 16 is connected to the tube material 10 via the connecting portions 14 and 17 (FIG. 2C). reference). As described above, the enlarged diameter portion 18 is provided on the upper end side of the connecting cylinder 16, and the lid 19 is provided on the upper end of the connecting cylinder 16 so as to be freely opened and closed. The mandrel 23 may be inserted into the tube material 10 without being pulled out when there is no hindrance in the subsequent work.

  The lid 19 is opened, and a grounding resistance reducing agent is preliminarily prepared and sealed, and for example, a tank 30 to which a liquefied carbon dioxide cylinder is connected is set at the upper end of the connecting cylinder 16 (see FIG. 2 (e)). . At this time, it is preferable that the jet outlet on the lower side of the tank 30 is formed so as to be fixed to the upper end portion of the connecting cylinder 16 through the enlarged diameter portion 18 by screwing or the like. Thereafter, the valve of the tank 30 is opened, and the grounding resistance reducing agent is press-fitted into the connecting cylinder 16 at once from the jet outlet. Thereby, the grounding resistance reducing agent is ejected from the through holes 13, 13,. At this time, the soil around the tube material 10 is liquefied by the impact of the sprayed ground resistance reducing agent and diffuses while being mixed with the ground resistance reducing agent (in this figure, the diffusion range at this time is set to R). Is shown.)

  After injecting the ground resistance reducing agent in this way, the ground resistance is measured, and it is confirmed that the measured value is smaller than the specified value. When the measured value is larger than the specified value, the ground resistance reducing agent is injected again by the above procedure to increase the injection amount of the ground resistance reducing agent. When the ground resistance is measured again and the measured value is still larger than the specified value, it can be confirmed that the measured value is smaller than the specified value by injecting the ground resistance reducing agent and measuring the ground resistance value. Repeat until. After confirming that the measured value of grounding resistance is smaller than the specified value, the tank 30 is removed and the lid 19 is closed (see FIG. 2 (f)).

  Although the injection of the ground resistance reducing agent may be performed in a pressurized state in the ground electrode 1 as described above, it is simply poured into the ground electrode 1 and a plurality of through holes 13, 13, It may be done by letting it flow out naturally. In that case, the mandrel 23 is inserted from the opening at the upper end of the connecting cylinder 16 and a downward external force is applied to the mandrel 23, so that the grounding resistance remaining in the tube material 10 by the action of the piston formed by the tube material 10 and the mandrel 23 is applied. It is possible to force the reducing agent to flow out of the through holes 13, 13,. The injection or pouring of the ground resistance reducing agent may be performed in a state where the connecting portion 14 of the ground electrode 1 shown in FIG. 2B is exposed from the ground. At this time, the mandrel 23 can be used together as appropriate. Of course, the mandrel 23 can be used when the ground resistance reducing agent remains in the tube 10 when the ground resistance reducing agent is injected in a pressurized state.

  In this way, when the increase in the ground resistance value of the ground electrode according to the present invention is observed by monitoring the ground resistance after the grounding work is completed, the repair work is required. In this renovation work, the lid 19 of the diameter-expanded portion 18 is opened and the ground resistance reducing agent is injected by the above-described method. Since the plurality of through-holes that have been made are held in an unblocked state, the outflow of the ground resistance reducing agent from the plurality of through-holes is not limited.

  The grounding electrode of the present invention is a state in which the inside of the pipe member and the connecting cylinder is in communication from the rod pressing surface which is the upper end surface of the closing member to the ground, the rod is inserted therein, and an external force is applied downward thereto. It can be driven into the ground and can also be injected with a ground resistance reducing agent. After the grounding work is completed, the lid 19 of the enlarged diameter portion 18 at the uppermost end of the grounding electrode 1 of the present invention is closed, and then the foreign matter in the tube material 10 of the grounding electrode 1 of the present invention. Intrusion can be prevented, and re-excavation can be eliminated in the repair work when the grounding resistance value of the grounding electrode increases. Further, by inserting a rod into the ground electrode of the present invention and driving it in, it is possible to suppress the intrusion of earth and sand from a through-hole drilled near the blocking member of the pipe, The installation work of an additional grounding rod can be made unnecessary.

  The ground electrode of the present invention is also separated by a predetermined distance (for example, about 1 m) in the vicinity thereof in accordance with a predetermined technical standard when an increase in the ground resistance value of the ground electrode such as an existing ground rod is recognized. Can be installed as an additional grounding pole. As a result, the additional grounding electrode can be made unnecessary for excavation in the subsequent renovation work, so that the labor and cost required for the renovation work can be reduced.

  FIG. 3 shows a state after the grounding work of the grounding pole of the embodiment shown in FIG. 1 is completed along the power pole. As shown in this figure, when the grounding electrode 1 of the present invention is driven along the utility pole 40, the total length of the connecting tube 16 can be set longer than that in the grounding work shown in FIG. The total length of the connecting cylinder 16 can be appropriately set in consideration of the workability of the worker in the future repair work (for example, the ground height from the ground to the lid 19 at the upper end of the connecting cylinder 16 is about 1 m. Such). As shown in FIG. 3, the connecting cylinder 16 can be fixed to the utility pole 40 with fixing bands 42, 42, 42 as it is, but it is a hard synthetic resin pipe having a diameter larger than the ground height of the connecting cylinder 16 and a long overall length. It is also possible to protect the connecting cylinder 16 by covering it.

  As described above, according to the grounding resistance reducing agent-injection type grounding electrode of the present invention, as shown in the above-described embodiments and examples of the grounding work method, the connecting cylinder is made to communicate between the grounding electrode and the ground. By opening the lid, it is possible to open the lid at the time of renovation work and to inject the ground resistance reducing agent, etc., and it is possible to eliminate excavation in the renovation work for the ground electrode. Further, the grounding resistance reducing agent-injected grounding electrode of the present invention inserts a rod body into a conductive tube at the time of placing, and presses a mandrel pressing surface formed on a closing member at the tip, thereby grounding of the present invention. The resistance-reducing agent-injection-type ground electrode can be driven into the ground, and at that time, intrusion of earth and sand or the like through a through-hole formed near the blocking member of the pipe can be suppressed.

DESCRIPTION OF SYMBOLS 1 Grounding resistance reducing agent injection | pouring type earthing electrode 10 Tubing material 11 Blocking member 11a Bar body pressing surface 12 Opening 13 Through-holes 14 and 17 Connection part 16 Connection cylinder 18 Expanded part 19 Lid 20 Lead terminal 21 Ground wire 23 Mandrel (rod)
30 tanks (equipped with compressed gas cylinder)
32 Pilot hole R Ground resistance reduction agent diffusion range

Claims (4)

  The distal end is closed by a conical member with a conical outer shape, and the base end can be connected directly to the opening end portion and the conductive tube material, or to the opening of the base end portion directly or via a connecting portion. And an electrically insulating connecting cylinder having a lid that can be opened and closed on its proximal end side, and a rod body pressing surface that is pressed by a rod body that is inserted into the tube material near the distal end in the tube material And a plurality of through holes penetrating inward and outward are disposed on the peripheral side surface in the vicinity of the rod pressing surface, and a ground wire connection terminal is provided near the base end portion. Grounding electrode with earth resistance reducing agent   2. The grounding electrode according to claim 1, wherein a size of a cross section perpendicular to the axial direction of the rod is set to be slightly smaller than an inner diameter of the tube material. Grounding resistance reducing agent injection type including a conductive tube having a distal end closed by a conical member having a conical outer shape and having an opening at a base end, and an electrically insulating connecting cylinder having a lid that can be opened and closed at one end. A grounding method using a grounding electrode,
Drilling a pilot hole in the ground;
Inserting the rod into the tube and transmitting the downward external force to the rod pressing surface to drive the ground electrode into the pilot hole;
Injecting or pouring a ground resistance reducing agent into the conductive tube;
Connecting the end opposite to the end having the lid portion of the connecting cylinder directly or indirectly through the connecting portion to the opening on the base end side of the ground electrode;
A grounding method characterized by including   The grounding method according to claim 3, wherein a size of a cross section perpendicular to the axial direction of the rod body is set to be slightly smaller than an inner diameter of the pipe material.

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