JP4256761B2 - Grounding device and construction method thereof - Google Patents

Description

The present invention relates to a grounding device for grounding equipment and the like and a construction method thereof.

In the conventional grounding device, as disclosed in Patent Document 1, the rod-shaped grounding body is driven into the ground at a distance of 75 cm or more from the ground surface at a distance from the grounding target device. The grounded device was grounded via the ground wire.
JP-A-5-182704

However, a rod-shaped grounding body placed on the ground has a high ground resistivity at the grounding location where the grounding body is placed, and a predetermined grounding resistance value is often not obtained. In this case, the grounding body is added. Because the grounding device having a predetermined grounding resistance value was installed by configuring a grounding body with a long length, or by constructing a grounding body by placing a plurality of grounding bodies in parallel. There was a problem that it took time and labor to install the grounding device.

In addition, in the case of soil with high earth resistivity, the earth resistance device is configured by using a grounding resistance reducing material in combination with a rod-shaped grounding body, so that the grounding resistance reducing material is aged with running water due to rain for many years. As a result, the ground resistance value at the time of installation cannot be maintained, and the function of the grounding device becomes unsatisfactory.

An object of the present invention is to solve the problems of the above-described conventional ground device and its construction method.

In order to achieve the above-described object, the present invention provides a grounding device having a support, a grounding body disposed along the support, and a conductive member that joins the grounding body and the support. The grounding body is attached to the central portion along the longitudinal direction of the central portion, the central portion formed as a vertically long strip-shaped plate material, the opposite side portions similarly formed as a vertically long strip-shaped plate material, and A tube body having a closed bottom and a perforated hole; and a wedge portion formed at a tip; and after the grounding body is installed on the ground, an upper opening of the tube body Then, by injecting the conductive member, the conductive member injected into the tube body passes from the through-hole drilled in the tube body to the center portion and the side portion of the ground body and the outer surface of the support body. It is configured to flow into the space formed by the above .

In order to achieve the above-described object, the present invention provides a grounding device construction method. First, a hole is excavated in the ground along a support embedded in the ground, and the ground is grounded in the hole. A pipe embedded in the body or driven into the ground along the support body, and then attached to the ground body, with the bottom closed and a through hole drilled By injecting a conductive member from the upper opening of the body, the conductive member injected into the tube body is inserted into the center portion, the side portion, and the support body from the through hole formed in the tube body. are those of the structure to flow into the space formed by an outer surface, the second, composed of a previous step of burying the support to the ground, the ground material, in so that the attachment to the support It is a thing.

Since this invention has the structure mentioned above, there can exist the effect described below.

An earth device is constituted by a support body embedded in the ground, a ground body disposed along the support body, and a conductive member joined to the ground body and the support body. By installing a common grounding resistance by installing a supporting body such as a concrete pillar having a low specific resistance and a grounding body disposed on the ground, it is easy to install, inexpensive, and changes over time. It is possible to configure a grounding device that is low in reliability and high in ground resistance.

Since the grounding device is composed of a support body buried in the ground, a grounding body disposed along the support body, and a conductive member joined to the grounding body and the support body, the grounding device is disposed on the ground. The grounding body and the support buried in the ground are securely joined by the conductive member, and therefore a stable grounding device with low grounding resistance can be configured.

According to a grounding device construction method, a hole is excavated in the ground along a support body buried in the ground, and a ground body is buried in the hole, or the ground body is grounded along the support body. Then, the support body and the grounding body are joined by a conductive member. Therefore, the support body, such as a concrete pillar having a low specific resistance, which is installed in a moist soil, is disposed on the ground. It is possible to obtain a common ground resistance by coexisting with the installed earth body, and to reliably and easily construct a highly reliable ground device having a low ground resistance value. The choice of work when installing a grounding body on an existing support is expanded.

The grounding device is attached to the support body in a pre-process for embedding the support body in the ground, and then the support body and the grounding body are joined by a conductive member, and then the conductive body is connected. Since the support body and the grounding body joined by the members are embedded in a hole excavated in the ground, the concrete pillar or the like having a low specific resistance is installed in moist soil. It is possible to obtain a common grounding resistance by combining the body and the grounding body disposed on the ground, and to reliably and easily construct a highly reliable grounding device having a low grounding resistance value. it can.

Hereinafter, examples of the present invention will be described. However, the present invention is not limited to these examples as long as the gist of the present invention is not exceeded.

Reference numeral 1 denotes a support body for attaching and supporting equipment such as power distribution lines and communication lines. As the support body 1, there are a steel column and a concrete column. This embodiment will be described. In addition, the equipment such as electrical equipment that is a target device for grounding is not limited to equipment installed on the upper part of the support 1 on which the grounding device is disposed, but is equipment installed on the upper part of another support. It may also be a facility device attached in addition to the support.

2 is a vertical hole excavated in the earth 3, a concrete pillar 1 is installed in the vertical hole 2, and the soil excavated during excavation is placed in the vertical hole 2 in which the concrete pillar 1 is installed, and the surface portion 4 of the earth 3. The concrete pillar 1 is installed on the ground 3.

5 is a grounding body, and the grounding body 5 is a vertically long extending from a central part 5a formed as a vertically long belt-like plate member and a longitudinal edge 5a1 of the central part 5a away from each other. And a side portion 5b formed as a strip-shaped plate material. The edge 5a1 of the central portion 5a is formed with a reinforcing rib 5c that is substantially perpendicular to the central portion 5a and extends in the longitudinal direction of the central portion 5a. , It is located closer to the center part 5a than the connecting line L1 connecting the tips of the opposite side parts 5b. In other words, a predetermined gap is formed between the leading end 5c1 of the reinforcing rib 5c and the connecting line L1 connecting the leading ends of the side portions 5b facing each other.

A tube 5d is attached to the center of the central portion 5a of the ground member 5 along the longitudinal direction of the central portion 5a. The lower end of the tube 5d is closed by a bottom 5d1. Further, an appropriate number of through holes 5d2 are formed in the lower portion of the tube body 5d. In addition, it is preferable that the outer periphery of the tubular body 5d is configured to be substantially in contact with the connecting line L1 that connects the distal ends of the opposite side portions 5b.

The central portion 5a constituting the grounding body 5 is formed as an inclined portion 5a2 inclined toward the connecting line L1 connecting the distal ends of the opposite side portions 5b at the distal end portion thereof, and is positioned near the inclined portion 5a2. The lower end portion of the side portion 5b on the inclined portion 5a2 side is formed as an inclined end portion 5b1 connected to the inclined portion 5a2. The tip of the grounding body 5 is formed as a wedge portion W by the inclined portion 5a2 of the central portion 5a and the inclined end portion 5b1 of the side portion 5b.

Reference numeral 6 denotes a connector. The connector 6 is formed of a conical tip portion 6a and a columnar portion 6b connected to the conical tip portion 6a. The connector 6 is a tube 5d constituting the grounding body 5. It is configured to be inserted into the upper opening 5d3. In addition, the protrusion 6c extended in the axial direction of the cylinder part 6b can be formed in the cylinder part 6b. By forming such a protrusion 6c, the connector 6 can be made difficult to come off from the tubular body 5d.

Reference numeral 7 denotes a ground wire, and the ground wire 7 is connected to the connector 6 via a connecting member 8.

Next, installation means for the grounding body 5 having the above-described configuration will be described.

With the wedge part W of the grounding body 5 facing downward, at least a part of the side part 5b of the grounding body 5 is in contact with the surface of the existing concrete pillar 1 installed on the ground 3, The ground 3 is driven to a predetermined depth using a hammer or a driving machine. Next, a conductive member C such as conductive cement or conductive grease is injected from the upper opening 5d3 of the tubular body 5d. The conductive member C injected from the upper opening 5d3 of the tubular body 5d passes through the through hole 5d2 drilled in the tubular body 5d and is formed by the central portion 5a and the side portion 5b of the ground body 5 and the outer surface 1a of the concrete column 1. It flows into the space A to be formed, and the space A and the tube 5d are filled with the conductive member C. In this way, the grounding body 5 and the concrete pillar 1 are electrically joined via the conductive member C. Next, the ground device E is installed on the concrete pillar 1 by inserting the connector 6 to which the ground wire 7 is connected via the connecting member 8 into the upper opening 5d3 of the tubular body 5d.

FIG. 1 shows an example in which the upper end of the ground body 5 protrudes from the ground surface portion 4 of the ground 3, but the upper end of the ground body 5 is positioned below the ground surface portion 4 of the ground 3. In this way, when the upper end of the grounding body 5 is located below the ground surface part 4 of the ground 3, the center part 5 a and the side part 5 b of the grounding body 5 and the outer surface of the concrete pillar 1 are used. After the conductive member C is filled in the space A and the tube 5d formed by 1a, it is preferable to fill the hole formed above the grounding body 5 with soil. When the upper end of the grounding body 5 protrudes from the ground surface portion 4 of the ground 3, the upper end of the grounding body 5 and the concrete pillar 1 can be fastened with a band (not shown). The upper end of the grounding body 5 protruding from the ground surface portion 4 can be configured to be covered with a suitable lid member.

In the above-described embodiment, an example in which the grounding body 5 is driven using a hammer or a driving machine along the surface of the existing concrete column 1 is shown, but the surface of the existing concrete column 1 is shown. The grounding body 5 is installed so that at least a part of the side part 5b of the grounding body 5 is in contact with the surface of the concrete pillar 1, and then the hole and the grounding are formed. It is also possible to configure so that the gap with the body 5 is filled with soil. Next, as described above, a conductive member C such as conductive cement or conductive grease is injected from the upper opening 5d3 of the tube 5d. In this way, the grounding body 5 and the concrete pillar 1 are electrically joined via the conductive member C. Thereafter, the ground device E is installed on the concrete pillar 1 by inserting the connector 6 to which the ground wire 7 is connected via the connecting member 8 into the upper opening 5d3 of the tubular body 5d.

In addition, when a new concrete pillar 1 is to be installed, a grounding body is used in advance by using an appropriate fastening means such as a band in the previous step of installing the concrete pillar 1 in the vertical hole 2 excavated in the ground 3. 5 is attached to the concrete pillar 1, and thereafter, similarly to the above, a conductive member C such as conductive cement or conductive grease is injected from the upper opening 5 d 3 of the pipe body 5 d, and the ground body 5 and the concrete pillar 1 are injected. Are electrically joined via the conductive member C. After that, the ground body 5 is installed in the vertical hole 2 excavated in the ground 3 with the concrete pillar 1 electrically joined via the conductive member C, and the vertical hole 2 in which the concrete pillar 1 is installed, The concrete pillar 1 is placed on the ground 3 by being backfilled with soil excavated during excavation. Before and after installation of the concrete pillar 1 on the ground 3, the connector 6 to which the ground wire 7 is connected via the connecting member 8 is inserted into the upper opening 5 d 3 of the tubular body 5 d, thereby providing concrete. The earth device E is installed on the pillar 1. In this case, since the grounding body 5 and the concrete pillar 1 can be joined on the ground surface, the grounding body 5 and the concrete pillar 1 can be reliably joined via the conductive member C. Therefore, the grounding device E having a low grounding resistance can be obtained.

As an experiment, a concrete pillar 1 having a diameter of about 40 to 45 cm is installed on a ground 3 having a ground resistivity of about 250 Ω · m, and then a ground body 5 having a length of about 150 cm is as described above. As a result, a ground resistance of 70Ω was obtained. This value corresponds to the value of the grounding resistance when a copper plate having a side of 90 cm square is buried to a depth of about 100 cm in the ground. In addition, when a grounding body having a total length of 150 cm was directly placed on the ground 3 and measured at the above experimental place, the grounding resistance was 130 to 150Ω. Considering the time and labor for excavating the earth 3 and refilling the excavated hole in order to bury the copper plate, and securing the copper plate burying place, etc., in the present invention, it is necessary to install the grounding device E. Time and labor can be saved significantly.

As described above, the outer periphery of the tubular body 5d constituting the grounding body 5 is configured so as to be substantially in contact with the connecting line L1 connecting the tips of the opposite side parts 5b, and the central part 5a of the buried grounding body 5 is provided. Since the pipe body 5d exists between the concrete body 1 and the concrete pillar 1, it is possible to prevent the ground body 5 from being damaged even when an external force is applied to the central portion 5a of the ground body 5. . Of course, the tube body 5d can be omitted if necessary.

As described above, since the grounding device 5 is connected to the concrete pillar 1 embedded in the ground 3 via the conductive member C as the grounding device E such as equipment, the predetermined grounding resistance is easy. In addition, it is possible to obtain a grounding device E having a long-term stable grounding resistance with little change with time.

Moreover, since the construction place of the earthing | grounding body 5 may be narrow, it can construct in the slight empty space of the existing concrete pillar 1, and as the earthing | grounding apparatus E, a large-scale construction is not required.

FIG. 1 is a front view including a partial cross section of the grounding device of the present invention. FIG. 2 is a plan view of a grounding body constituting the grounding device of the present invention. FIG. 3 is a perspective view of a grounding body constituting the grounding device of the present invention. FIG. 4 is a partial horizontal sectional view of the grounding device of the present invention. FIG. 5 is a front view of a connector, a ground wire and the like constituting the ground device of the present invention.

Explanation of symbols

C ······ Conductive member E ······· Earth device 1 ·········································· Vertical hole 3 ... Earth 5 ... Ground 5d ... Pipe 6 ... Connector 7 ... ······ground wire

Claims (3)

In a grounding device having a support, a grounding body disposed along the support, and a conductive member that joins the grounding body and the support, the grounding body is formed as a vertically long strip-shaped plate member. A central portion, opposite side portions that are also formed as vertically long strips, and attached to the central portion along the longitudinal direction of the central portion, with a closed bottom and a through hole. The tubular body, and after the grounding body is installed on the ground, by injecting a conductive member from the upper opening of the tubular body, The conductive member injected into the tube body is configured to flow from a through hole formed in the tube body into a space portion formed by the center portion and the side portion of the ground body and the outer surface of the support body. A grounding device characterized by comprising: A hole is excavated in the ground along the support body buried in the ground, and a grounding body is buried in the hole, or the grounding body is driven into the ground along the support body, and then the grounding is performed. By injecting a conductive member from an upper opening of a tubular body attached to the body and having a closed bottom and a through hole, the conductive member injected into the tubular body is Construction of a grounding device, characterized in that the grounding device is configured to flow from a through-hole formed in a body into a space formed by a central portion and a side portion of the grounding body and an outer surface of the supporting body. Method. At step before embedding the support to the ground, the ground material, the construction method of the grounding device according to claim 2, characterized in that it is configured to so that attachment to the support.

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