grounding rod

Abstract

To suppress the increase of a ground resistance value of a ground rod due to rainwater, etc.SOLUTION: A recessed rainwater receiver 3 extending in the circumferential direction is provided on the surface of a rod-shaped ground rod main body 2, and the cross-sectional shape of the rainwater receiver 3 slopes downward from the surface side of the ground rod main body 2 toward the inside, and the rainwater receiver is formed to receive liquid matter including rainwater W from above and flow it downward.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a ground rod that is buried underground to release unsteady current generated in electrical equipment into the ground. [Background technology]

[0002] Traditionally, grounding work for power distribution lines has mainly involved driving cylindrical grounding rods / grounding electrodes into the ground, selecting locations near utility poles where they can be buried. However, although the initial grounding work meets or exceeds the specified ground resistance value, subsequent periodic measurements have sometimes shown that the ground resistance value exceeds the specified value. In such cases, it is necessary to restore the ground resistance to the specified value, which requires a great deal of time, effort, and expense for on-site surveys, design, approval from landowners, and re-construction.

[0003] On the other hand, in order to reduce the ground resistance value of a ground rod, a reducing agent may be supplied to the burial hole, and there is a known grounding method that can save on the amount of reducing agent used (see, for example, Patent Document 1). This method involves burying a ground rod with a recess formed on its surface so that at least a part of the recess is buried in the ground, allowing the reducing agent to enter the recess. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-48957 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, stones and soil of different sizes are mixed around a grounding rod buried underground, and it is thought that over time, the pebbles will move downward, creating gaps between the grounding rod and the soil. Furthermore, when rainwater or other water flows downward along the surface of the grounding rod, the movement of the pebbles will be accelerated, and the gap between the grounding rod and the soil will become larger and wider, which is thought to increase the grounding resistance value of the grounding rod.

[0006] In contrast, the construction method described in Patent Document 1 can reduce the amount of reducing agent used, but it is difficult to prevent or suppress the occurrence or increase of gaps between the ground rod and the soil. In other words, it is difficult to prevent or suppress the increase in the ground resistance value of the ground rod due to rainwater, etc.

[0007] Therefore, an object of the present invention is to provide a ground rod that can suppress an increase in ground resistance due to rainwater, etc. [Means for solving the problem]

[0008] In order to solve the above problem, the invention of claim 1 is a method of forming a grounding rod by applying a circumferential force to the surface of the grounding rod body. Ring-shaped The extending concave rainwater catcher multiple The cross-sectional shape of the rainwater receiving portion is inclined downward from the surface side of the grounding rod body toward the inside, and is formed to receive liquid matter including rainwater from above and flow it downward, A concave connecting groove portion extending in the vertical direction and connecting the plurality of rainwater receiving portions is provided on the surface of the ground rod body. The ground rod is characterized by the above.

[0009] The invention of claim 2 is characterized in that, in the ground rod described in claim 1, the upper edge of the rainwater receiving portion is formed in an arc shape, making it easier for the liquid material from above to enter the rainwater receiving portion. [Effects of the Invention]

[0012] According to the invention described in claim 1, the cross-sectional shape of the rainwater receiver slopes downward from the surface of the ground rod body toward the inside, allowing rainwater and other water from above to be received by the rainwater receiver and flow downward. This prevents or suppresses the movement of pebbles and other particles that would otherwise move as rainwater flows downward along the surface of the ground rod body, creating or increasing gaps between the ground rod body and the soil. As a result, it is possible to suppress an increase in the ground resistance value of the ground rod due to rainwater and other factors.

[0013] Also The cross-sectional shape of the rainwater receiver slopes downward from the surface of the grounding rod body to the inside, so particles such as pebbles can easily enter the rainwater receiver, reducing the grounding resistance of the grounding rod. As a result, it is possible to prevent the grounding resistance of the grounding rod from exceeding the specified value over time. Furthermore, because the multiple ring-shaped rainwater catchers are connected by connecting grooves, rainwater that has entered the multiple rainwater catchers flows reliably downward along the connecting grooves, making it possible to further prevent the grounding resistance of the grounding rod from increasing due to rainwater or other factors.

[0014] According to the invention described in claim 2, the upper edge of the rainwater receiver is formed in an arc shape, which makes it easier for rainwater and the like to enter the rainwater receiver from above, making it possible to more reliably prevent rainwater and the like from flowing downward along the surface of the grounding rod body. As a result, it is possible to more effectively prevent the grounding resistance value of the grounding rod from increasing due to rainwater and the like. [Brief explanation of the drawings]

[0017] [Figure 1] 1A is an overall view showing a ground rod according to a first embodiment of the present invention, and FIG. 1B is an enlarged cross-sectional view of a rainwater receiving portion of the ground rod. [Figure 2] 2A is a diagram showing the flow of rainwater in the ground rod of FIG. 1, and FIG. 2B is a diagram showing the flow of rainwater in a conventional ground rod. [Figure 3] 10A and 10B are a front view and a side view showing the vicinity of a rainwater receiving portion of a ground rod according to a second embodiment of the present invention. [Figure 4] 10A and 10B are enlarged cross-sectional views showing examples of shapes of other rainwater receiving portions in the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will be described below based on the illustrated embodiments.

[0019] (Embodiment 1) 1 and 2(a) show this embodiment, and Fig. 1(a) is an overall view of a ground rod 1 according to this embodiment, and Fig. 1(b) is an enlarged cross-sectional view of the rainwater receiving portion 3 of this ground rod 1. This ground rod 1 is a ground electrode that is buried underground to allow unsteady currents generated in electrical equipment to escape into the ground, and on the surface of the rod-shaped ground rod body 2, a rainwater receiving portion 3 with a concave cross section that extends circumferentially is provided.

[0020] The ground rod body 2 is a conductive, straight, approximately round rod with a tip 2a formed in a roughly inverted cone shape, and is driven roughly vertically into the ground. A conductor 22 for inducing a non-steady current is attached to the base end (opposite the tip 2a) via a terminal 21.

[0021] The cross-sectional shape of the rainwater receiving portion 3 slopes downward from the surface side of the ground rod body 2 toward the inside, and is formed so as to receive liquid matter including rainwater W from above and allow it to flow downward to the ground rod body 2. That is, the cross-sectional shape in a vertical cross section passing through the axis of the ground rod body 2 is a roughly U-shaped groove that slopes downward from the surface side to the inside of the ground rod body 2, and in this embodiment, the upper side 3a and lower side 3b are roughly parallel, and the inside and bottom of the ground rod body 2 are formed in an arc shape.

[0022] The inclination angle of the rainwater receiving portion 3 is set so that it can easily receive rainwater W flowing from above (from the surrounding soil R) and so that the received rainwater W does not easily leak out. The width (distance between the upper side 3a and the lower side 3b) and length / depth of the rainwater receiving portion 3 are set so that it can sufficiently receive rainwater W and so that it does not flow onto the surface of the grounding rod main body 2 (the surface where the rainwater receiving portion 3 is not formed), and so that the strength of the grounding rod main body 2 is ensured to be above a predetermined level. Furthermore, the rainwater receiving portion 3 is set so that particles R1 such as pebbles that fit closely together with almost no gaps can enter the rainwater receiving portion 3, but large stones that create gaps (gaps that would increase the grounding resistance value of the grounding rod 1) cannot enter the rainwater receiving portion 3.

[0023] In addition, the upper edge 3c of the rainwater receiving portion 3, i.e., the corner formed by the surface of the grounding rod main body 2 and the upper edge 3a, is formed in an arc shape, making it easier for rainwater W and the like to enter the rainwater receiving portion 3 from above.

[0024] This rainwater receiving portion 3 is provided in a spiral shape on the ground rod body 2. In other words, the rainwater receiving portion 3 is formed over substantially the entire length of the ground rod body 2, wrapping around the surface of the ground rod body 2 in a spiral shape. As a result, the rainwater receiving portion 3 extends in the circumferential direction of the ground rod body 2 while inclining downwards, and receives rainwater W and the like, which flows downwards. The pitch of this spiral is set so that the rainwater receiving portion 3 can sufficiently receive rainwater W and the like that flows (seeps out) from the surrounding soil R, preventing or suppressing the occurrence or increase of gaps between the ground rod body 2 and the soil R, which will be described later, and so that the strength of the ground rod body 2 is secured to a predetermined level.

[0025] With a ground rod 1 configured in this way, the cross-sectional shape of the rainwater receiving portion 3 slopes downward from the surface side of the ground rod main body 2 toward the inside, and rainwater W from above is received by the rainwater receiving portion 3 and flows downward. As a result, rainwater W flows downward along the surface of the ground rod main body 2 (the surface on which the rainwater receiving portion 3 is not formed), which causes particles R1 such as pebbles to move, making it possible to prevent or suppress the occurrence and enlargement of gaps between the ground rod main body 2 and the soil R.

[0026] 2(b), rainwater W seeping out from the surrounding soil R flows downward along the surface of the ground rod 100, washing away particles R1 such as pebbles around the ground rod 100. This causes gaps to form or increase between the ground rod 100 and the soil R, increasing the ground resistance of the ground rod 100.

[0027] In contrast, in the case of the present ground rod 1, as shown in Figure 2(a), rainwater W and other substances seeping out from the surrounding soil R are received by the rainwater receiver 3 and flow along the rainwater receiver 3 downward toward the ground rod body 2. As a result, rainwater W and other substances flow downward along the surface of the ground rod body 2 (the surface where the rainwater receiver 3 is not formed), which causes particles R1 such as pebbles to move, preventing or suppressing the occurrence or expansion of gaps between the ground rod body 2 and the soil R. In other words, even if rainwater W and other substances flow from above, the particles R1 remain around the ground rod body 2, preventing or suppressing the occurrence or expansion of gaps between the ground rod body 2 and the soil R. As a result, it is possible to suppress an increase in the ground resistance value of the ground rod 1 due to rainwater W and other substances.

[0028] Furthermore, because the cross-sectional shape of the rainwater receiving section 3 slopes downward from the surface side of the grounding rod body 2 toward the inside, particles R1 such as pebbles can easily enter the rainwater receiving section 3, and the penetration of particles R1 into the rainwater receiving section 3 reduces the grounding resistance value of the grounding rod 1. As a result, it is possible to prevent the grounding resistance value of the grounding rod 1 from exceeding the specified value over time.

[0029] Furthermore, the upper edge 3c of the rainwater receiving portion 3 is formed in an arc shape, which makes it easier for rainwater W and the like to enter the rainwater receiving portion 3 from above, making it possible to more reliably prevent the rainwater W and the like from flowing downward along the surface of the grounding rod body 2. As a result, it is possible to more effectively prevent the grounding resistance value of the grounding rod 1 from increasing due to the rainwater W and the like.

[0030] Furthermore, since the rainwater receiving portion 3 is provided in a spiral shape, the rainwater W etc. that enters the rainwater receiving portion 3 flows reliably downward along the spiral rainwater receiving portion 3. As a result, it is possible to further suppress an increase in the ground resistance value of the grounding rod 1 due to the rainwater W etc.

[0031] (Embodiment 2) 3A and 3B are a front view and a side view, respectively, showing the vicinity of the rainwater receiving portion 3 of the ground rod 10 according to this embodiment, and the same components as those in the first embodiment are designated by the same reference numerals and will not be described further. This embodiment differs from the first embodiment in that the ground rod body 2 is provided with a plurality of ring-shaped rainwater receiving portions 3 and connecting groove portions 4.

[0032] Each rainwater receiver 3 extends in a ring-like or annular shape around the circumferential direction of the ground rod body 2, with the ring surface (the surface encompassing the ring) tilted obliquely relative to the axis of the ground rod body 2. This allows the received rainwater W to flow downward, i.e., toward the lowest part 31 of the rainwater receiver 3. Multiple rainwater receivers 3 are provided along the axial direction of the ground rod body 2, spanning substantially the entire length. The spacing between them is set, similar to the spiral pitch in the first embodiment, so as to prevent or suppress the occurrence or increase of gaps between the ground rod body 2 and the soil R, and to ensure that the strength of the ground rod body 2 is at a predetermined level or higher. In this embodiment, the lowest parts 31 of each rainwater receiver 3 are provided at the same position around the circumferential direction of the ground rod body 2.

[0033] The connecting groove 4 is a groove with a concave cross section that is provided on the surface of the ground rod body 2 and extends in the vertical direction to connect multiple rainwater receiving sections 3. That is, in this embodiment, it connects vertically adjacent rainwater receiving sections 3 at the lowest section 31 and is formed so as to extend in a straight line through all of the rainwater receiving sections 3. This connecting groove 4 extends from the base end side to the tip end 2a side of the ground rod body 2. The cross section of the connecting groove 4 may have any shape as long as it can receive rainwater W from the rainwater receiving sections 3 and flow it downward, and may be set to a U-shape, for example.

[0034] According to this embodiment, since the plurality of ring-shaped rainwater receiving portions 3 are connected by the connecting groove portion 4, the rainwater W and the like that enters the plurality of rainwater receiving portions 3 reliably flows downward along the connecting groove portion 4. As a result, it is possible to further suppress an increase in the ground resistance value of the ground rod 10 due to the rainwater W and the like.

[0035] Although the embodiments of the present invention have been described in detail above, the specific configuration is not limited to these embodiments, and design changes that do not deviate from the gist of the present invention are also included in the present invention. For example, the shape of the rainwater receiving portion 3 is not limited to the above-mentioned shape, and it may have a cross-sectional shape that slopes downward from the surface side of the ground rod body 2 toward the inside and receives rainwater W and channels it downward. For example, as shown in Figure 4, the rainwater receiving portion 5 may have a cross-sectional shape that is approximately triangular, with its hypotenuse 5a sloping downward from the surface side of the ground rod body 2 toward the inside and its base 5b approximately perpendicular to the axis of the ground rod body 2.

[0036] Furthermore, in the second embodiment, the case where the connecting groove 4 extends in a straight line so as to penetrate all of the rainwater receiving portions 3 has been described, but vertically adjacent rainwater receiving portions 3 may also be connected by the connecting groove 4 at different positions in the circumferential direction of the ground rod body 2. In other words, the lowest portions 31 of the rainwater receiving portions 3 may be offset in the circumferential direction of the ground rod body 2. [Explanation of symbols]

[0037] 1, 10 ground rod 2 Ground rod body 3 Rainwater receiving section 3a Top 3b Bottom side 3c Upper edge 4 Connecting groove R soil R1 particles W Rainwater (liquid)

Claims

1. A plurality of concave rainwater receiving sections extending in a ring shape in the circumferential direction are provided on the surface of the rod-shaped grounding rod body, The cross-sectional shape of the rainwater receiving portion is inclined downward from the surface side of the grounding rod body toward the inside, and is formed so as to receive liquid matter including rainwater from above and flow it downward, A concave connecting groove portion extending in the vertical direction and connecting the plurality of rainwater receiving portions is provided on the surface of the ground rod body. A ground rod characterized by:

2. The upper edge of the rainwater receiving portion is formed in an arc shape, so that the liquid from above can easily enter the rainwater receiving portion.

2. The ground rod according to claim 1.

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