JP4716888B2 - Grounding rod and method for making the same - Google Patents

Description

  The present invention relates to a grounding rod that is connected to a ground wire of an electrical facility and buried vertically in the ground, and in the event of an electrical leakage or lightning in the electrical facility, the current escapes into the ground and protects the peripheral equipment. It relates to the creation method.

  The grounding rod is connected to the ground wire of the electrical equipment in order to release the current into the ground and protect the peripheral equipment in the event of an electrical leakage or lightning in the electrical equipment, and is buried vertically in the ground.

  Conventionally, a grounding rod is a metal rod with a sharp tip, which is driven into the ground like a pile and connected to the ground wire of electrical equipment.

  At this time, depending on the ground resistance of the soil, the ground resistance value, which is the electrical resistance value between the ground rod and the soil, may not be sufficiently low. A sufficiently low grounding resistance value was obtained by using a deep grounding electrode to reach a lower, deeper formation.

  In addition, the following document describes a grounding rod having a configuration capable of reducing a contact resistance between the grounding rod and the ground by supplying a chemical resistance reducing agent to the surrounding soil as needed. Has been.

JP 2001-167820 A

  However, the grounding rod as described above requires a separate grounding rod and a chemical resistance reducing agent, so that equipment costs are required. Chemical resistance reducing agents can also contaminate the soil.

  On the other hand, electric power companies generate a large amount of wires to be discarded, and are required to be reused effectively because of the need for environmental considerations.

  The present invention has been made in view of the above situation, and an object of the present invention is to provide a grounding rod capable of reducing grounding resistance by an inexpensive means while considering the environment, and a method for producing such a grounding rod. Is to provide.

The present invention is a grounding rod that is connected to a ground wire of an electrical facility and is buried vertically in the ground, and each end of a plurality of electric wires is connected to the periphery thereof , and each of the plurality of electric wires has a bar at each upper end. The lower end of each is connected through a movable member attached so as to be movable in the length direction of the rod .

In the embodiment of the present invention, it is desirable to provide a limiting member that limits the movement range of the movable member at a portion of the grounding rod that is positioned between the upper and lower ends of the plurality of electric wires .

The method of the present invention is a method for creating a grounding rod that is connected to a ground wire of an electrical facility and buried vertically in the ground, and a plurality of electric wires cut into a predetermined length around a metal rod. The lower end is connected by being tightened by a conductor sleeve.

  Since the grounding rod of the present invention has a plurality of electric wires connected to its periphery, the surface area of the conductor increases by the number of wires in addition to the rod that contacts the surrounding soil when buried, so that the grounding resistance can be reduced. . In addition, the electric wire only needs to be a conductor having a certain length, and it may be a CV electric wire or a low-voltage lead wire that is usually discarded, so that the electric wire that is a waste material can be reused. Can do. Thus, it is possible to provide a grounding rod that reduces the grounding resistance at a cost that is almost the same as that of the prior art while considering the environment.

The upper end of the wire is fixedly connected with respect to ground rods, the lower end of the wire is connected through a movable member Runode, wire bending by the movable member to move upward during embedding, the ends of the wires Opens from the stick in the shape of a lantern . For this reason , the surface area of the conductor in contact with the surrounding soil can be increased, and the grounding resistance can be further reduced. On the other hand, when the wire is pulled out, the wire is stretched and closed to facilitate the pulling out of the grounding rod. In addition, the wires are prevented from falling off, and the environment becomes more environmentally friendly.

  Furthermore, by restricting the movement of the movable member with the limiting member provided in the main body part between the upper end and the lower end of the electric wire, the opening of the electric wire can be stopped in an optimal state, so that when the grounding rod is embedded The surface area of the conductor that contacts the surrounding soil can be optimized to set the ground resistance to a minimum.

According to the method for producing a grounding rod of the present invention, the upper ends of a plurality of wires cut to a predetermined length are fixed and connected around the metal rod, and the lower ends of each wire are movable in the length direction of the rod. Since the surface area of the conductor increases by the number of electric wires in addition to the rod that contacts the surrounding soil when buried, the grounding resistance can be reduced. In addition, the electric wire only needs to have a predetermined length, and may be a stripped CV electric wire or a low-voltage lead-in wire that is normally discarded, so that the electric wire that is a waste material can be reused. As a result, it is possible to create a grounding rod that reduces the grounding resistance at a cost that is almost the same as the conventional one while considering the environment.

  A grounding rod 1 shown in FIG. 1 includes a main body 2 and electric wire portions 3a and 3b. When the grounding rod 1 is buried in the ground, it is driven almost perpendicularly to the ground, so the upper end is the upper end and the lower end is the lower end in the figure.

  The main body 2 is an elongated metal rod, and a conventional grounding rod can be used as it is. Its length is designed according to the soil and the required grounding resistance. Further, a plurality of bars may be connected in series to form a single bar.

  Since the lower end 4 of the main body 2 is pointed in a conical shape, the grounding rod 1 can be driven and embedded in the ground without performing prior drilling by boring.

  A protruding stopper 5 is provided at the upper end of the main body 2. This is to prevent the ground wire from dropping in the upper end direction of the main body 2 when the grounding rod 1 is buried in the ground after the ground wire connected to the electrical equipment is wound around the main body 2.

  Each of the electric wire portions 3 a and 3 b includes a plurality of electric wires 6 a and 6 b and sleeves 7 a and 7 b for connecting them to the main body 2 in a fixed manner.

  The electric wires 6a and 6b are conductor wires and are connected to the conductor body 2 in a conductive manner. If the surface area of the electric wires 6a and 6b is large, the grounding resistance is reduced. Therefore, the number and length thereof are designed according to the soil and the required grounding resistance.

  The sleeves 7a and 7b are short cylindrical members having substantially the same inner diameter as the outer diameter of the main body 2. The sleeves 7a and 7b are fixed to the main body 2 by tightening the electric wires 6a and 6b. Prevents falling off.

  Since the upper ends of the electric wires 6a and 6b are not fixed to the main body 2, the upper ends of the electric wires 6a and 6b are opened in a flower shape as shown in FIG.

The electric wire portions 3a and 3b are attached near the lower end of the main body 2 in order to efficiently reduce the ground resistance and prevent accidents. The number of the wire portions 3a and 3b shown in the figure is an example, and can be increased or decreased in order to optimize the grounding resistance.
Since this grounding rod only needs to fix one end of the electric wire, it is easy to increase the number of electric wires and the number of electric wires per sleeve can be increased, so that the grounding resistance can be further reduced.

  Tables 1 and 2 show that the grounding resistance of a conventional grounding rod with a diameter of 10 mm and the grounding resistance of a grounding rod connected with an electric wire as shown in FIG. The value is actually measured.

  Table 1 compares the grounding resistance values of each grounding rod installed in Kojimachi, Fukuyama City.

  Table 2 compares the grounding resistance values of the grounding rods installed in the soil with a lot of moisture near Niihama-cho, Fukuyama City.

  From the above experimental results, it can be seen that the grounding rod to which the electric wire is connected as shown in FIG. 1 has a grounding resistance value that is approximately 30% to 50% lower than the conventional grounding rod, and is greatly reduced.

The grounding rod 11 shown in FIG. 2 includes a main body 12 and an electric wire portion 13. When the grounding rod 11 is buried in the ground, it is driven perpendicularly to the ground, so the upper end is the upper end and the lower end is the lower end in the figure.

The main body 12 is an elongated metal rod, and a conventional grounding rod can be used as it is. The length is selected according to the soil and the required grounding resistance. Alternatively, a plurality of bars may be connected to form a single bar.

  Since the lower end 14 of the main body 12 is pointed in a conical shape, the grounding rod 11 can be driven into the ground and embedded without performing prior drilling by boring.

  A protruding stopper 15 is provided at the upper end of the main body 12. This is to prevent the ground wire from dropping in the upper end direction of the main body 12 when the grounding rod 11 is buried in the ground after the ground wire connected to the electrical equipment is wound around the main body 12.

  The electric wire portion 13 includes a plurality of electric wires 16, an upper sleeve 17 a for fixedly connecting them to the main body 12, and a lower sleeve 17 b as a movable member that can slide along the main body 12.

  The electric wire 16 is a conductor wire, and is similarly connected to the conductor body 12 in a conductive manner. If the electric wires 16a and 16b have a large surface area, the grounding resistance is reduced. Therefore, the number and length of the electric wires 16a and 16b are designed according to the soil and the required grounding resistance.

  The upper sleeve 17a is a short cylindrical member having an inner diameter that is substantially the same as the outer diameter of the main body 12. The upper sleeve 17a is fixed to the main body 12 by tightening the upper end of the electric wire 16, and the electric wire 16 is caused by friction with soil during embedment. Prevent falling out. Further, the lower sleeve 17b is a short cylindrical member having an inner diameter slightly larger than the outer diameter of the main body 12, and the outer diameter of the lower end is the outer diameter of the upper end in order to reduce the frictional resistance with the soil when buried. It is getting smaller. The lower end of the electric wire 16 is connected to the lower sleeve 17b by means of welding or the like to prevent the electric wire 16 from dropping due to friction with the soil during embedment.

  A sleeve-shaped stopper 18 for limiting the range of movement of the lower sleeve 17b is provided at a portion of the main body 12 located between the upper sleeve 17a and the lower sleeve 17b. This is a short cylindrical member having an inner diameter substantially the same as the outer diameter of the main body 12 and larger than the inner diameter of the lower sleeve 17b, and is fixed to the main body 12 by appropriate means such as welding. Is done. As a result, the lower sleeve 17b cannot move above the sleeve stopper 18. Further, since the lower sleeve 17b is connected to the upper sleeve 17a via the electric wire 16, it cannot move downward when the electric wire 16 is fully extended.

  The electric wire portion 13 is attached near the lower end of the main body 12 in order to reduce ground resistance and prevent accidents. In addition, the number of the electric wire parts 13 does not need to be one, and can be increased in order to optimize the grounding resistance.

  Hereinafter, a method for embedding the grounding rods 1 and 11 will be described.

  First, in order to bury the grounding rod at a specified depth to prevent an accident, a hole 20 having a depth of 75 cm is dug in the ground G as shown in FIGS.

  Next, the grounding rod 1 or 11 stands vertically against the bottom of the hole 20 and is inserted into the ground G. At this time, since the lower end 4 or 14 is pointed conically, it can be easily inserted.

Here, in the grounding rod 11 of FIG. 2 , as shown in FIG. 4, when the lower sleeve 17 b hits the ground G, and the grounding rod 11 is further inserted into the ground G, the sleeve 17 b is relatively moved along the main body 12. And slides upward until it hits the sleeve-like stopper 18. At that time, the electric wire 16 bends due to the interval between the upper and lower sleeves 15a, 15b being shortened, so that the central portion is separated from the main body 12 and spreads in a lantern shape as a whole. As a result, electricity can be released over a wide range, and the ground resistance can be further reduced.

On the other hand, since the grounding rod 1 in FIG. 1 does not have a moving sleeve, it is inserted into the ground G without any change in form as shown in FIG.

  When almost the entire grounding rod 1 or 11 is buried in the ground, the ground wire 30 is wound around the lower part of the stopper 5 or 15 in the main body 2 or 12. Then, as shown in FIGS. 5 and 6, the grounding rod is completely embedded. In order to prevent accidents, the portion of the ground wire 30 that is 75 cm or more below the ground G is insulated and protected by the insulating tube 31.

  If the pillar 32 supporting the electrical equipment to be grounded is made of metal, the interval between the pillar 32 and the grounding rod 1 or 11 is set to 100 cm in order to prevent the current from the grounding rod 1 or 11 from flowing through the pillar 32. Open more.

  When burying the grounding rod, the grounding rod may hit the bedrock in the ground and may not be able to be inserted further into the ground. In such a case, the grounding rod is pulled out and buried again in another place.

In ground rods 1 of FIG. 1, the wire 6a, only the sleeve 7a lower end of 6b, since the fixed to the main body 2 at 7b, when pulled upward, wire 6a, the upper end of 6b away from the body 2 As a result, the flower opens as a whole. This is a resistance against the pulling out of the grounding rod 1.

On the other hand, in the grounding rod 11 of FIG. 2 , the electric wire 16 is open in a lantern shape as described above during embedment, but when the main body 12 is pulled upward, the lower sleeve 17b is relatively moved by friction with soil. The electric wire 16 is straightened by pulling both ends of the electric wire 16 to the upper and lower sleeves 17a and 17b, and is in close contact with the main body 12, so that it can be easily pulled out. In addition, as above-mentioned, since a grounding resistance changes with forms of a grounding rod, what is necessary is just to employ | adopt the form suitable for the geology of the land to drive.

  Although the illustrated embodiments have been described above, the present invention is not limited to these embodiments, and various forms and modifications can be made according to the actual usage.

The front view which shows a 1st grounding rod. The front view which shows the 2nd grounding rod. The figure which shows the aspect at the time of insertion to the ground of a 1st grounding rod. The figure which shows the aspect at the time of insertion to the ground of the 2nd grounding rod. The figure which shows the state after embedding a 1st grounding rod. The figure which shows the state after embedding the 2nd grounding rod.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,11 ... Ground rod, 2,12 ... Main body, 3a, 3b, 13 ... Electric wire part, 4, 14 ... Lower end, 5,15 ... Stopper, 6a, 6b, 16 ... Electric wire, 7a, 7b, 17a, 17b ... Sleeve, 18 ... Sleeve stopper, 20 ... Hole, 30 ... Ground wire, 31 ... Insulating tube, 32 ... Pillar.

Claims (3)

It is a grounding rod that is connected to the ground wire of electrical equipment and buried vertically in the ground,
It is configured by connecting each end of multiple wires around it ,
The plurality of electric wires are fixedly connected at their upper ends, and each lower end is connected via a movable member attached so as to be movable in the length direction of the rod. The grounding rod according to claim 1,
A grounding rod , wherein a limiting member for limiting a moving range of the movable member is provided at a position between the upper end and the lower end of the plurality of electric wires. A method of creating a grounding rod that is connected to the ground wire of an electrical facility and buried vertically in the ground,
Around the metal rod, the upper ends of a plurality of wires cut to a predetermined length are fixed and connected, and each lower end is connected via a movable member attached movably in the length direction of the rod. A method of creating a featured grounding rod.

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