JP2012079509A - Ground rod - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ground rod of which the amount used necessary to make a ground resistance value equal to or lower than a specified value can be reduced.SOLUTION: The ground rod has electrical conductivity, is formed long in one direction, and is buried underground to release a ground current into the ground. A contact area expansion part composed of recesses or protrusions is formed on a surface of that portion of the ground rod which is buried underground.

Description

  The present invention embeds unsteady currents that are buried in the ground and may occur in equipment such as lightning arresters and transformers (for example, equipment on poles such as lightning arresters and transformers installed on power poles). It relates to the grounding rod for escape.

  Generally, for equipment such as lightning arresters and transformers, grounding measures may be taken to prevent unsteady currents that may be generated by lightning strikes, etc., into the ground and prevent equipment failures and electric shock accidents. . One aspect of this is grounding measures using a grounding rod. There are various types of grounding rods, and one of them is the grounding rod 1 as shown in FIG. 5A (see Patent Document 1).

  The grounding rod 1 has conductivity and is formed long in one direction. Since the grounding rod 1 is buried in the ground, the base end portion is hit with a hammer or the like, but the base end portion may be damaged along with this, so a wedge member (not shown) is attached and detached. It is configured to be possible. Further, as shown in FIG. 5B, the base end portion of the grounding rod 1 is connected to a terminal T for electrically connecting a lead L such as a lead wire or a grounding wire for inducing an unsteady current, The tip of the grounding rod 1 is also detachable.

  And the said grounding rod 1 is thrust at the place where a front-end | tip part embeds, and a front end side is embed | buried in the ground by being struck with a hammer etc. from the base end side. At that time, the ground rod 1 is connected to the base end portion of the wedge member. Then, the grounding rod 1 buried in the ground is detached from the wedge member connected to the base end portion, and the terminal T is connected (see FIG. 5B).

  And as for the grounding rod 1 embed | buried in the ground, as shown to Fig.6 (a), the surface of the part embed | buried is in contact with the earth. Therefore, the grounding rod 1 can release current from the portion of the surface that is in contact with the ground. As a result, the grounding rod 1 can escape from the portion in contact with the ground as an unsteady current flowing through the terminal T as a grounding current. Therefore, the grounding rod 1 can prevent an equipment failure and an electric shock accident by letting an unsteady current flow into the ground.

JP-A-9-298073

  By the way, when the grounding rod 1 is buried in the ground, the grounding resistance value must be equal to or less than a specified value stipulated by a ministerial ordinance (a certain amount of current must be allowed to escape into the ground. ). Therefore, when the grounding resistance value of the grounding rod 1 previously buried is not below the specified value, another grounding rod 1 is connected to the grounding rod 1 buried previously as shown in FIG. Or bury another grounding rod 1 in the vicinity of the grounding rod 1 previously buried (a position several meters away from the grounding rod 1 buried previously) as shown in FIG. Thus, the ground resistance value is reduced to a specified value or less.

  From the above, there is a concern that a large number of grounding rods 1 used in conventional grounding countermeasures are used in order to reduce the grounding resistance value to a specified value or less.

  In view of this situation, an object of the present invention is to provide a grounding rod that can reduce the amount of use required to reduce the grounding resistance value to a specified value or less.

  A grounding rod according to the present invention is a grounding rod that has conductivity, is formed long in one direction, is buried in the ground and allows ground current to escape into the ground, and is buried in the ground. A contact area enlarged portion made of a concave portion or a convex portion is formed on the surface of the portion.

  According to the grounding rod having the above configuration, since the concave portion or the convex portion is formed on the surface of the portion embedded in the ground, the surface area is increased as compared with the case where the surface is smooth. As a result, when the grounding rod is buried in the ground, the area in contact with the ground is also increased. Accordingly, the grounding rod having the above-described configuration can discharge a larger amount of current into the ground than when the surface is smooth, so that a low grounding resistance value can be realized.

  Moreover, as one aspect of the present invention, it is preferable that the contact area expanding portion is formed of a spiral groove formed on the surface of a portion embedded in the ground. According to the grounding rod having the above-described configuration, since the spiral groove is formed on the surface of the portion buried in the ground, the surface area is increased as compared with the case where the surface is smooth. As a result, when the grounding rod is buried in the ground, the area in contact with the ground is also increased. Accordingly, the grounding rod having the above-described configuration can discharge a larger amount of current into the ground than when the surface is smooth, so that a low grounding resistance value can be realized.

  Furthermore, as another aspect of the present invention, the contact area enlarging part comprises a core part that has conductivity and is formed long in one direction, and a surface layer part that covers the surface of the core part. Is formed of a spiral groove formed on the surface of the surface layer portion in a portion embedded in the ground, and the groove is formed at a depth at which the core portion is exposed from the surface layer portion, or the core portion is formed from the surface layer portion. It may be formed at a depth that is not exposed.

  According to the grounding rod having the above-described configuration, since the spiral groove is formed on the surface of the portion buried in the ground, the surface area is increased as compared with the case where the surface is smooth. As a result, when the grounding rod is buried in the ground, the area in contact with the ground is also increased. Therefore, the grounding rod having the above configuration can discharge a larger amount of current into the ground than a grounding rod having a smooth surface, so that a low grounding resistance value can be realized.

  In addition, the grounding rod formed with a depth at which the core is exposed from the surface layer portion has a large surface area according to the depth of the groove, so that the effect of lowering the grounding resistance value is increased, while the groove is The grounding rod formed with a depth that does not expose the core portion from the surface layer portion can prevent the strength of the surface layer portion from being weakened, and since the surface layer portion is difficult to peel off during embedding and drawing, it is embedded It is possible to realize a low ground resistance value while ensuring durability.

  Further, as another aspect of the present invention, it is provided with a conductive core portion that is elongated in one direction and a surface layer portion that covers the surface of the core portion, and is embedded in the ground. A spiral groove is formed on the surface of the core portion of the surface portion, and the surface layer portion covers the surface along the shape of the core portion, whereby the contact area enlarged portion is formed on the surface layer portion. preferable.

  According to the grounding rod having the above configuration, since the surface layer portion is configured to cover the surface along the shape of the core portion in which the spiral groove is formed, the surface layer is formed in forming the contact area expanding portion. The thickness of the part is not impaired. For this reason, the grounding rod having the above-described configuration can form the contact area expanding portion deeper, and the surface area becomes larger than when the spiral groove is directly provided in the surface layer portion. Thereby, when this grounding rod is embed | buried in the ground, the area which contacts the underground also becomes large. Accordingly, the grounding rod having the above-described configuration can discharge a larger amount of current into the ground than when the surface is smooth, so that a low grounding resistance value can be realized.

  As described above, since the grounding rod of the present invention can discharge more current into the ground than when the surface is smooth, the grounding necessary for making the grounding resistance value equal to or less than the specified value. The outstanding effect that the usage-amount of a stick | rod can be reduced can be show | played.

It is a figure which shows the grounding rod which concerns on one Embodiment of this invention, Comprising: (a) shows the whole schematic, (b) shows the partial cross-section enlarged view. BRIEF DESCRIPTION OF THE DRAWINGS It is the whole schematic diagram which shows the state by which the grounding rod which concerns on the same embodiment was embed | buried, Comprising: (a) shows the state by which it was embed | buried alone, (b) is different from the grounding rod buried previously. The state where the grounding rod is connected and buried is shown, and (c) shows the state where another grounding rod is buried at a location apart from the previously buried grounding rod. It is the whole schematic figure in the embedding state of the grounding rod concerning the embodiment, (a) shows the grounding rod embedded alone, (b) is another grounding to the grounding rod embedded previously. The state where the rods are connected and buried is shown. It is a figure which shows the grounding rod which concerns on other embodiment of this invention, Comprising: (a) shows the whole schematic, (b) shows the partial cross-section enlarged view. It is a figure which shows the conventional grounding rod, Comprising: (a) shows the whole schematic, (b) shows the whole schematic which shows the state in which the terminal was connected. It is the whole schematic diagram which shows the state where the conventional grounding rod was embed | buried, Comprising: (a) shows the state embed | buried by itself, (b) is another grounding rod added to the grounding rod previously embedded. FIG. 4C shows a state in which the grounding rod is connected and buried, and FIG. 5C shows a state in which another grounding rod is buried at a location separated from the grounding rod previously buried.

  Hereinafter, a grounding rod according to an embodiment of the present invention will be described with reference to the accompanying drawings.

  The grounding rod according to the present embodiment has conductivity, is formed long in one direction, and is buried (injected) into the ground to release the grounding current into the ground. As shown in FIG. 1A, the grounding rod includes a rod-like member 10 formed in a rod shape and a connecting member 11 formed in a cylindrical shape. The base end part of the rod-shaped member 10 is connected.

  More specifically, the rod-shaped member 10 includes a core portion 100 (see FIG. 1B) that is elongated in one direction, and a surface layer portion 101 that covers the surface of the core portion 100. Yes. Furthermore, the core part 100 has conductivity and is formed in a rod shape using a hard material (for example, steel material). The core portion 100 is provided with a fitting portion 102 drilled from the proximal end surface toward the distal end. Further, the core portion 100 is formed with a sharp tip.

  And as shown in FIG.1 (b), the said surface layer part 101 is formed by coat | covering the surface of the said core part 10 with a highly conductive raw material (for example, copper). Further, the surface layer portion 101 has a spiral groove 103 (corresponding to a surface area enlargement portion of the present invention) formed on the surface (excluding a sharp portion) in a portion embedded in the ground.

  In the grounding rod 1 according to the present embodiment, the surface area expansion effect is expected as the depth of the groove 103 increases. Therefore, the grounding rod 1 may have the groove 103 formed at a depth at which the core portion 10 is exposed from the surface layer portion 101, but there is a problem that the strength of the surface layer portion 101 is lowered. Therefore, in consideration of the strength of the surface layer portion 101, the grounding rod 1 is preferably formed with a depth at which the groove 103 does not expose the core portion 10 from the surface layer portion 101.

  Note that the depth of the groove 103 when the core portion 10 is not exposed from the surface layer portion 101 is preferably set to 90% or less of the thickness of the surface layer portion 101, and further, 80% of the thickness of the surface layer portion 101. More preferably, it is set as follows. In consideration of the strength of the surface layer portion 101, the grounding rod 1 preferably has a pitch of the grooves 103 (interval between adjacent portions of the grooves 103 in the longitudinal direction of the grounding rod 1) of 2 cm or more.

  The connecting member 11 includes a main body 110 formed in a cylindrical shape from a conductive material. Furthermore, the inner periphery of the main body 110 is formed slightly more than the outer periphery of the rod-shaped body 10. Since the main body 110 is formed in a cylindrical shape, an opening (insertion portion 111a) is formed at one end in the same direction as the center line, and an (insertion portion 111b) is formed at the other end. Has been. Further, the connecting member 11 is provided with a crimping portion 112 having a small inner periphery formed by pressing a part on one end side.

  By the way, since the grounding rod 1 according to the present embodiment is buried in the ground, the base end portion is struck with a hammer or the like. Not used). The wedge member is formed in a rod shape, and the base end portion is formed to have a length protruding from the other end surface of the connecting member 11 in a state where the distal end portion is inserted into the insertion portion 111b.

  Furthermore, the grounding rod 1 according to the present embodiment is a terminal T (see FIGS. 3 and 4) that electrically connects a lead wire L or a grounding wire L or the like through which a ground current generated in equipment or the like flows. Is used. The terminal T is formed in a rod shape, and its outer periphery is set slightly larger than the inner periphery of the connecting member 11. Further, the terminal T is formed with such a length that the proximal end side protrudes from the other end surface of the connecting member 11 in a state where the distal end portion is inserted into the insertion portion 111 b.

  This completes the description of the grounding rod 1 according to the present embodiment. Subsequently, with reference to FIG. 2 and FIG. 3, the ground rod 1 is buried and an abnormal current (ground current) that may be generated in the equipment due to lightning strikes or the like can be released into the ground. explain.

  The grounding rod 1 according to the present embodiment is usually provided in a state where the base end portion of the rod-shaped member 10 is inserted into one end portion of the connecting member 11. Further, since the grounding rod 1 is firmly fixed by the crimping portion 112, it cannot be easily pulled out. The grounding rod 1 may be provided in a state where the rod-shaped member 10 and the connecting member 11 are not connected. In this case, the base end portion of the rod-shaped member 11 is inserted into one end portion of the connecting member 11. The operation of pressing a part to form the crimping part 112 is performed locally.

  The grounding rod 1 is in a state in which the distal end portion of the wedge member is inserted into the insertion portion 111 b and the distal end portion of the wedge member is in contact with the core portion 100 that defines the bottom surface of the insertion portion 102. Therefore, the tip of the rod-shaped member 10 is formed by bringing the grounding rod 1 into a state where the tip of the rod-shaped member 10 is projected to the ground surface to be grounded and hitting the base end of the wedge member with a hammer or the like in this state. The part will be buried underground. At this time, the grounding rod 1 can be easily embedded because the tip of the rod-shaped member 10 is sharply formed.

  And after this grounding rod 1 is embed | buried, the wedge member inserted in the insertion part 111b is removed. The wedge member can be easily pulled out because the outer periphery is set slightly smaller than the inner periphery of the connecting member.

  Thereafter, the tip of the terminal T is inserted into the insertion part 111 b of the grounding rod 1. Since the outer periphery of the terminal T is set slightly larger than the inner periphery of the connecting member 11, the terminal T is inserted while expanding the inner peripheral surface of the connecting member 11. As a result, the terminal T is firmly connected to the connecting member 11. In addition, a lead wire such as a lead wire or a ground wire is electrically connected to a portion of the terminal T protruding from the other end surface of the connecting member 11.

  Normally, the terminal T is provided with a through hole penetrating in a direction orthogonal to the longitudinal direction at a portion protruding from the other end surface of the connecting member 11, and a conducting wire is inserted from one end side of the through hole. And the terminal T is made into the state from which the conducting wire L came out from the other end side of the through-hole, and the conducting wire L is electrically connected by welding the other end side of a through-hole.

  The grounding rod 1 in the state shown in FIG. 2A is in a state where the surface of the rod-shaped member 10 is in contact with the ground. In addition, in this state, the grounding rod 1 has a spiral groove 103 formed in the surface layer portion 101, so that the surface layer portion 101 defining the groove 103 is also in contact with the ground. As a result, when an unsteady current is generated, the grounding rod 1 can release the current into the ground. Furthermore, since the grounding rod 1 has a large area in contact with the ground as compared with the case where the surface is formed to be smooth, more current can be released into the ground.

  As described above, since the grounding rod 1 according to the present embodiment can release more current into the ground than when the surface is smooth, in order to make the grounding resistance value below a specified value. The outstanding effect that the usage-amount of a required grounding rod can be reduced can be show | played.

  In addition, the grounding rod of the present invention is not limited to the above-described embodiment, and various changes can be made without departing from the scope of the present invention.

  For example, in the above-described embodiment, only one grounding rod 1 is embedded. However, the present invention is not limited to this, and the grounding resistance value does not become a specified value or less when one grounding rod 1 is used in the grounding work. If the grounding resistance value of the existing grounding rod 1 has exceeded a specified value due to corrosion or the like, as shown in FIG. A plurality of ground bars 1 may be used in series by inserting the tip of another ground bar 1.

  In the above embodiment, only one grounding rod 1 is embedded. However, the present invention is not limited to this, and in the grounding work, when one grounding rod 1 is used, the grounding resistance value does not become a specified value or less. Or, if the grounding resistance value of the existing grounding rod 1 exceeds the specified value due to corrosion or the like, as shown in FIG. 2 (c), the vicinity of the grounding rod 1 previously buried (being buried first) A plurality of grounding rods 1 may be used in parallel by embedding another grounding rod 1 at a position several meters away from the grounding rod 1.

  Moreover, in the said embodiment, although the grounding rod 1 was comprised by inserting the base end part of the rod-shaped member 10 in the one end part of the connection member 11, it is not limited to this, For example, a rod-shaped member 10 and the connecting member 11 (having the function of the connecting member 11) may be integrally formed.

  Moreover, in the said embodiment, although the said groove | channel 103 was directly formed in the surface layer part 101, it is not limited to this, For example, as shown to Fig.4 (a), (b), the core part 100 of FIG. A spiral groove 103 ′ is formed on the surface, and the surface layer portion 101 is covered with the surface along the shape of the core portion 100, whereby the groove 103 (corresponding to the contact area expanding portion of the present invention) is formed in the surface layer portion 101. May be formed.

  In this way, the surface layer portion 101 can form a deeper groove 103 without damaging the thickness of the surface layer portion 101 when forming the groove 103. Therefore, the grounding rod 1 in which the groove 103 ′ is formed in the core portion 101 can further increase the contact area with the ground while maintaining the strength of the surface layer portion 101, and the grounding current that can be released into the ground. The amount can be increased.

  Moreover, in the said embodiment, although the said groove | channel 103 is formed only 1 item | strip | row, it is not limited to this, For example, you may form multiple items | stripes, such as 2 item | stripes and 3 items | stripes.

  Moreover, in the said embodiment, although the said groove | channel 103 was formed helically, it is not limited to this, For example, the groove | channel which made the longitudinal direction the same direction as the longitudinal direction of the rod-shaped member 10 over the circumferential direction. A plurality of them may be provided.

  Moreover, in the said embodiment, although the said groove | channel 103 was formed in the helical form, it is not limited to this, For example, the groove | channel provided along the circumferential direction of the rod-shaped member 10 is multiple in a longitudinal direction. It may be provided.

  Moreover, in the said embodiment, although the said groove | channel 103 was formed in helical shape, it is not limited to this, For example, a some recessed part is formed in the whole surface of the part embed | buried under the ground of the rod-shaped member 10. It may be provided.

  Moreover, although the said groove | channel 103 was employ | adopted in the said embodiment, it is not limited to this, For example, the helical convex part formed in the surface in the part embed | buried under the ground of a surface layer part is provided. Also good.

  Moreover, although the said groove | channel 103 was employ | adopted in the said embodiment, it is not limited to this, For example, you may provide the partial protrusion formed in the whole surface in the part embed | buried in the ground of a surface layer part. .

  DESCRIPTION OF SYMBOLS 1 ... Ground rod, 10 ... Bar-shaped member, 11 ... Connecting member, 100 ... Core part, 101 ... Surface layer part, 102 ... Insertion part, 103 ... Groove, 103 '... Groove formation part, 110 ... Main body, 111a, 111b ... Difference Insertion part, 112 ... Crimp part, L ... Conductor, T ... Terminal

Claims (5)

  A grounding rod that has conductivity and is elongated in one direction and is buried in the ground to release ground current into the ground, and has a concave or convex surface on the surface of the part buried in the ground. A grounding rod characterized in that a contact area enlarged portion made of a portion is formed.   2. The grounding rod according to claim 1, wherein the contact area expanding portion is a spiral groove formed on a surface of a portion embedded in the ground.   It has conductivity and comprises a core portion that is formed long in one direction and a surface layer portion that covers the surface of the core portion, and the contact area enlarged portion is a portion embedded in the ground. 2. The grounding rod according to claim 1, comprising a spiral groove formed on a surface of the surface layer portion, the groove being formed at a depth at which the core portion is exposed from the surface layer portion.   It has conductivity and comprises a core portion that is formed long in one direction and a surface layer portion that covers the surface of the core portion, and the contact area enlarged portion is a portion embedded in the ground. The grounding rod according to claim 1, comprising a spiral groove formed on a surface of the surface layer portion, the groove being set to a depth at which the core portion is not exposed from the surface layer portion.   It has conductivity and has a core portion that is elongated in one direction and a surface layer portion that covers the surface of the core portion, and has a spiral shape on the surface of the core portion in the portion embedded in the ground The grounding rod according to claim 1, wherein the groove is formed, and the surface layer portion covers the surface along the shape of the core portion, whereby the contact area enlarged portion is formed on the surface layer portion.

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