JP5443410B2 - Lightning suppression type lightning arrester - Google Patents

Description

  The present invention relates to a lightning-suppressing lightning arrester for protecting a protected body such as a building or equipment from lightning damage by suppressing lightning.

  In the conventional lightning protection concept, from the viewpoint that lightning strikes cannot be prevented, most of the methods receive lightning strikes to a ground with a pointed lightning rod (Franklin rod).

In recent years, the concept of lightning protection has been revised, and there is a movement (new JIS A4201 2003 edition) that shifts from the angle method to the rotating sphere method, but in any case, it has been difficult to completely eliminate the damage caused by lightning. In particular, when the scale of lightning strike (current value and duration) is large, such as winter lightning, various damages are caused by the lightning current itself and the potential increase of the ground.
Furthermore, recent devices tend to be vulnerable to abnormal currents due to the integration of ICs, and the problem of lightning strikes is increasing.

On the other hand, a charge dissipation type lightning protection system (DAS) has been developed as a technology for preventing lightning (see Patent Document 1). However, this system is expensive because it is a large-scale equipment, and it is actually used only for special equipment.
In recent years, a deionization capacity type lightning rod (PDCE) has appeared as a technique for suppressing a lightning strike and has been effective (see Patent Document 2 and Patent Document 3).

  Lightning strikes are discharge phenomena that occur in the atmosphere. Lightning discharges include in-cloud discharges, inter-cloud discharges, and cloud-ground discharges. It is the cloud-to-ground discharge (hereinafter referred to as lightning strike) that causes significant damage from lightning discharge. A lightning strike is a phenomenon that occurs when the electric field strength between a thundercloud (cloud bottom) and a structure constructed on the earth or ground becomes very large, and its charge is saturated to break the insulation of the atmosphere. is there.

When lightning phenomenon is observed in detail, in the case of a general lightning strike (summer lightning) that occurs in summer, when the thundercloud matures, the step leader approaches the ground while selecting the place where the step leader tends to discharge from the atmosphere.
When the step leader is at a certain distance from the ground, a weak current upward streamer (greeting discharge) extends from the ground, a building (lightning rod), or a tree toward the step leader.
When this streamer and step leader are coupled, a large current (feedback current) flows between the thundercloud and the ground through the path. This is a lightning phenomenon.

  The deionization capacity type lightning rod (PDCE) described in Patent Document 2 is a lightning suppression type lightning rod, which is less likely to generate an upward streamer. For this reason, lightning strikes are unlikely to occur at facilities where the PDCE is installed at the highest part.

  This PDCE has an upper electrode body and a lower electrode body arranged with an insulator interposed therebetween, and only the lower electrode body is grounded. Therefore, for example, when a thundercloud with negative charges distributed at the bottom of the cloud approaches, the opposite charge (plus charge) is distributed on the surface of the ground, and as it approaches saturation, the lower electrode body also has a positive charge. Get together. Then, the upper electrode body arranged via the insulator is negatively charged by the action of the capacitor. This action makes it difficult to generate upward streamers in the PDCE and its surroundings, and suppresses the occurrence of lightning strikes.

As a result of installing PDCE in Hokuriku and using lightning observation cameras and LLS (Lightning Location System) for lightning for 5 years, no lightning was observed in the PDCE installation in summer.
From these observation results, it was found that PDCE prevents return current (prevents lightning strike) and suppresses damage caused by lightning strikes during summer thunder.

JP-A-8-273715 JP 2008-10241 A JP 2010-205687 A

The present inventors have found that the suppression effect can be increased by increasing the insulation between the upper and lower electrode bodies of the PDCE while studying the mechanism of summer thunder suppression by the PDCE. Yes.
By the way, a lightning strike (winter lightning) seen in winter is caused by a so-called upward discharge phenomenon in which a step leader is generated in a direction opposite to that of summer lightning, that is, upward from the ground. If the current value of the upward discharge is small, it does not lead to lightning, but if it is large, it leads to lightning. Therefore, in order to suppress winter lightning, it is effective to reduce the current value of upward discharge.

In the course of our research, PDCE can not completely eliminate this upward discharge phenomenon, but once the insulation between the upper and lower electrode bodies of PDCE is effective against summer lightning, It has been found that the current value of the upward upward discharge may increase.
In other words, in the performance of the PDCE, if a sufficient effect on the summer lightning was realized, the problem of conversely increasing the risk of the occurrence of winter lightning was encountered.

  Then, this invention makes it a subject to provide the lightning suppression type lightning arrester which can fully exhibit the lightning strike suppression effect with respect to a winter lightning, while exhibiting the lightning strike suppression effect with respect to a summer lightning.

  In order to solve the above-described problems, a lightning suppression type lightning arrester according to the present invention includes a lightning pole member having an insulator that insulates an upper electrode body and a lower electrode body, and a conductive part provided at a lower part of the lightning pole member. And a support member for supporting the lightning pole member and the needle member.

  According to the present invention, since the conductive pin member is provided below the lightning pole member, the current value of the upward discharge is reduced by the interaction between the needle member and the lightning pole member, thereby suppressing lightning strikes for winter lightning. The effect can be enhanced.

  In the present invention, the projecting needle member preferably includes a plurality of projecting needle portions, and each projecting needle portion is preferably arranged radially. Thus, by arranging the respective projecting needle portions radially, it is possible to disperse the influence of the electric charge that each of the projecting needle portions exerts on the lightning protection pole member and to make it almost uniform overall.

  In this invention, it is preferable that the horizontal distance L between the front-end | tip of the said needle part and the perpendicular line which passes along the center of the said lightning pole member is less than 5 times the height difference h with the vertex of the said lightning pole member. . By doing in this way, a big upward discharge current can be suppressed.

  In the present invention, it is preferable that the protruding needle member is disposed directly under the lightning pole member. When the projecting needle member is disposed directly under the lightning pole member, the distance between the lightning pole member and the projecting needle member in the horizontal direction can be made sufficiently small to achieve a compact configuration. In addition, since the projected area from above does not increase, it is possible to achieve a configuration that is hardly affected by snow accumulation or the like.

  In the present invention, it is preferable that the axis of the lightning protection pole member, the axis of the needle member, and the axis of the support member are arranged so as to be substantially the same axis. When comprised in this way, a lightning pole member and a stylus member can be connected by a single ground wire, and the whole can be made compact.

  In the present invention, it is preferable that the lower electrode body and the protruding needle member are grounded via a support member. Thus, when grounding via a support member, a part of grounding wire can be omitted and simplified.

  According to the present invention, due to the interaction between the lightning pole member and the tip member, the upward discharge current value is reduced, and the lightning suppression effect against the winter lightning is exhibited sufficiently while the lightning suppression effect against the summer lightning is exhibited. It is possible to provide a lightning suppression type lightning arrester that can be performed.

1 is a partial cross-sectional front view of a lightning suppression lightning arrester according to an embodiment of the present invention. It is a perspective view of the stylus member of the lightning suppression type lightning arrester according to the embodiment of the present invention. It is a top view which shows the example of the other needle member of the lightning strike suppression lightning arrester which concerns on embodiment of this invention. It is explanatory drawing which shows the experiment example of the lightning strike suppression type lightning arrester which concerns on embodiment of this invention. It is explanatory drawing which shows the experiment example of the lightning strike suppression type lightning arrester which concerns on embodiment of this invention. It is a longitudinal cross-sectional view of the lightning strike suppression lightning arrester which concerns on other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
FIG. 1 is a view showing an embodiment in which the present invention is applied to a deionization capacity type lightning rod, and a characteristic portion is shown in cross section.

  As shown in FIGS. 1 and 2, a lightning-suppressing lightning arrester A according to this embodiment includes a lightning pole member 1 disposed at the top, and a conductive stylus member provided below the lightning pole member 1. 2, and a support member 3 that supports the lightning pole member 1 and the projecting needle member 2.

  The lightning pole member 1 includes an upper electrode body 11, a lower electrode body 12, and an insulator 13 provided between the upper electrode body 11 and the lower electrode body 12, and is formed in a substantially spherical shape as a whole. . The upper electrode body 11 and the lower electrode body 12 are formed in a slightly flat hemispherical shape in which a sphere is divided in half. Therefore, those surfaces are formed as curved surface portions 11a and 12a that come into contact with the atmosphere. The upper electrode body 11 and the lower electrode body 12 are formed in a cavity, for example, as shown in FIG. Further, a downward convex portion 11 b and an upward convex portion 12 b facing each other from the top surface of the upper electrode body 11 and the inner bottom surface of the lower electrode body 12 are formed.

  As shown in FIG. 1, the insulator 13 is formed in a thick cylindrical shape or donut shape, and is provided so as to maintain an electrical insulation state between the upper and lower electrode bodies 11 and 12. Accordingly, it is sufficient that the function as an insulating material between the upper electrode body 11 and the lower electrode body 12 can be exhibited, and the shape and the like are arbitrary. However, the lightning pole member 1 in this embodiment has a structure in which the insulation between the upper and lower electrode bodies 11 and 12 is strengthened by increasing the thickness and outer diameter of the insulator in order to increase the lightning suppression effect. ing. The upper and lower electrode bodies 11 and 12 are connected via an insulator 13. For the connection, fastening means such as bolt connection, welding, adhesion, and fitting, and connection means can be used. In addition, about this lightning pole member 1, the lightning pole member etc. which are described in patent document 2 and patent document 3 can also be employ | adopted suitably.

  The upper electrode body 11, the lower electrode body 12, the protruding needle member 2 and the support member 3 of the lightning protection member 1 are made of a durable and conductive metal such as stainless steel. The lower electrode body 12 is electrically connected to the ground via the support member 3 and a grounding conductor (ground wire) (not shown). Thereby, in the state where this lightning suppression type lightning arrester A is installed vertically, when the ground or structure is charged with a positive charge due to the influence of thunderclouds or the like, the surface of the upper electrode body 11 is charged with a negative charge. When the structure or the like is charged with a negative charge, the surface of the upper electrode body is designed to be charged with a positive charge. This charging function itself is based on the same principle as that of the existing PDCE.

  The needle member 2 includes a columnar attachment portion 21 and a plurality of needle portions 22 extending radially from the attachment portion 21. Although the number of the protruding needle portions 22 is not particularly limited, in the present embodiment, it is set to four at equal intervals around the horizontal as shown in FIG. 2, or about three as shown in FIG. Of course, the number of the projecting needle portions 22 may be four or more.

  A number of screw holes 21 a corresponding to the number of the projecting needle members 2 are provided on the outer peripheral surface of the cylindrical mounting portion 21 at equal intervals in the circumferential direction. And the base end part of the protruding needle part 22 is screwed and fixed with respect to these screw holes 21a. In this case, it may be attached by welding instead of screw connection, or may be used in combination.

  The entire projecting needle member 2 is disposed immediately below the lightning pole member 1 (below the insulator 13). As shown in FIG. 1, the length of the projecting needle portion 22 in the horizontal direction is shorter than the radius of the insulator 13, and consideration is given so as not to protrude outward from the outer peripheral surface of the insulator 13. An upper end surface 21 b (see FIGS. 1 and 2) of the attachment portion 21 of the projecting needle member 2 is formed in a curved surface corresponding to the curved lower surface of the lower electrode body 12. Thereby, the upper end surface 21 b of the attachment portion 21 is in close contact with the lower surface of the lower electrode body 12. A screw hole 21 c is provided in the center of the attachment portion 21 of the projecting needle member 2.

  The support member 3 includes a support rod 31 located at the center and a support pipe 32 arranged coaxially on the outside thereof. The support rod 31 is formed with a male screw 31a that is screwed into the screw hole 21c of the protruding needle member 2. The support member 3 is fixed by tightening a nut 33 screwed into the male screw 31a. A pipe flange 34 is provided at the lower part of the support pipe 32, and nuts 35, 35 are screwed into the male screw portion of the support bar 31 penetrating therethrough. Therefore, in the present embodiment, as shown in FIG. 1, the axis of the lightning pole member 1, the axis of the needle member 2, and the axis of the support member 3 are configured to be substantially the same axis. By comprising in this way, the lightning pole member 1 and the stylus member 2 can be connected by a single ground wire, and the whole can be made compact.

  In addition, the horizontal distance L between the tip of the protruding portion 22 and the vertical line (axis) y passing through the center of the lightning pole member 1 is set within 5 times the height difference h from the top of the lightning pole member 1. ing. This is based on the experimental results to be described later, and considers that when the horizontal distance L is 5 times or more of the height difference h, the lightning suppression effect in the enlarged region is reduced.

The effect of the lightning suppression type lightning arrester according to the present invention could be confirmed by the following field test or indoor experiment.
That is, if the insulation between the upper electrode body and the lower electrode body of the lightning pole member is strengthened in order to improve the PDCE characteristics against lightning in the winter season, the upward discharge current value per one time becomes larger, and the influence is increased. It was necessary to consider. As a countermeasure in this case, it was confirmed from the field test that when a small needle is provided near the lightning pole member, the upward discharge current value per time can be controlled within a certain range.

(1) Field test In the field test, a projecting needle member was provided so that the projecting needle portion was located at a position lower by 10 cm or more at a location 20 cm away from the center of the PDCE, and was confirmed for 5 years.
In this field test, a maximum discharge current of 8 kA was confirmed for PDCE alone in a winter lightning occurrence region, but when a needle member was provided, only an upward discharge current of 4 kA or less was confirmed. In addition, there was no noticeable damage to the equipment and the surrounding area.

  In the above field test, when the needle member was provided near the PDCE, the upward discharge current value could be controlled to 4 kA or less compared to the case of the single PDCE. It was considered that this was to affect the discharge characteristics between the PDCE and the thundercloud. That is, it was considered that the projecting needle member near the PDCE dissipates electric charge around it and causes a phenomenon that optimizes the discharge characteristics of the PDCE.

  If the above consideration is certain, it is considered that the action of reducing the upward discharge current per time becomes larger as the horizontal distance between the protruding portion of the protruding member and the PDCE is shorter.

(2) Indoor test Then, an indoor test was conducted to determine how close the horizontal distance between the stylus part of the stylus member and the PDCE is, and the upward discharge current becomes smaller and lightning can be prevented almost completely. .
Experiment 1 (control example)
A conventional lightning rod (protruding needle) 20 was used to create an environment in which discharge occurred. FIG. 4 (a)
Experiment 2 (reference example)
When the PDCE 10 was installed alone in the environment created in Experiment 1, the PDCE 10 did not discharge. FIG. 4 (b)
Experiment 3 (comparative example)
When the PDCE 10 and the projecting needle 20 were installed in the environment created in Experiment 1 so that the heights of both were the same, the PDCE 10 was not discharged but only the projecting needle 20 was discharged. FIG.

Experiment 4 (Example)
In the environment created in Experiment 1, the PDCE 10 and the projecting needle 20 are installed so that the height of the projecting needle 20 is h1 = 10 cm lower than the PDCE 10, and the horizontal distance L1 between the PDCE 10 and the projecting needle 20 is variously changed. In this case, it was tested whether or not discharge occurred. FIG.
As a result, it was confirmed that at least the discharge did not occur when the horizontal distance L1 between the PDCE and the projecting needle was 50 cm.
From this result, at least the horizontal distance L of the needle portion 22 of the needle member 2 is set to be within 5 times the height difference h between the apex of the lightning pole member 1 and the needle portion 22, thereby suppressing a large upward discharge current. I found out that

  From these test results, when the stylus member is provided near the PDCE as compared with the case of the single PDCE, the upward discharge current value can be controlled lower. It was revealed that the same phenomenon as that in the case of lowering occurred and that the distance between the projecting portion of the projecting member and the PDCE was important for lowering the upward discharge current value.

When the number of the protruding portion is one as in the above test, the distance from the protruding portion varies at each point of the insulator of the lightning pole member.
Under actual meteorological conditions, the charged state of the atmosphere is not uniform, and therefore, a point at a distance far from the protruding portion of the insulating portion is easily discharged.
In order to solve this problem, it is important to make the distance from the protruding needle portion as uniform as possible at each point of the insulator.

The lightning-suppressing type lightning arrester of the present invention in which a plurality of protruding needle portions 22 are provided around the lower portion of the lightning protection pole member 1 is such that the distance from the protruding needle portion 22 is made as uniform as possible at each point of the insulator 13. By arranging in this way, it is possible to disperse the influence of the electric charge on each lightning pole member by each of the projecting needle portions and make it almost uniform as a whole.
Moreover, by setting it as such a structure, the influence of the snow accumulation, snowfall, etc. with respect to the needle member 2 can be excluded, and it became possible to fully exhibit the effect | action of the needle member 2. FIG.

  FIG. 6 is a longitudinal sectional view showing another embodiment of the lightning suppression lightning arrester according to the present invention. In the same embodiment, components that are basically the same as those of the previous embodiment are denoted by the same reference numerals and description thereof is simplified.

  The lightning-suppressing lightning arrester B according to this embodiment also includes a lightning pole member 1 disposed at the top, a conductive needle member 2 provided at the lower part of the lightning pole member 1, a lightning pole member 1 and a needle member. 2 and a support member 3 that supports 2.

  The lightning pole member 1 includes an upper electrode body 11, a lower electrode body 12, and an insulator 13 provided between the upper electrode body 11 and the lower electrode body 12, and is formed in a substantially spherical shape as a whole. . The upper electrode body 11 and the lower electrode body 12 are formed in a slightly flat hemispherical shape in which a sphere is divided in half. Therefore, those surfaces are formed as curved surface portions 11a and 12a that come into contact with the atmosphere. The upper electrode body 11 and the lower electrode body 12 are formed in a cavity. Further, a downward convex portion 11b and an upward convex portion 12b for discharge are formed facing each other from the top surface of the upper electrode body 11 and the inner bottom surface of the lower electrode body 12.

The insulator 13 includes a cylindrical outer insulator 13a and an inner insulator 13b fitted inside. The inner insulator 13b is formed in a thick cylindrical shape, and is provided to reinforce the electrical insulation state between the upper and lower electrode bodies 11, 12. The outer insulator 13a is longer and thinner than the inner insulator. On the surfaces (the lower surface and the upper surface) where the upper electrode body 11 and the lower electrode body 12 face each other, annular grooves 11c and 12c that circulate in the circumferential direction are formed, and the upper and lower ends of the outer insulator 13 are formed in the annular grooves 11c and 12c. It is fitted and integrated.
The insulator 13 may be formed by integrally forming the outer insulator 13a and the inner insulator 13b. Moreover, it is good also as a structure using only the outer side insulator 13a.

  An insulating cover 15 is attached to the outside of the insulator 13 via a separator 14 made of the same insulating material. The insulating cover 15 includes an inner cylinder portion 15a and an outer cylinder portion 15b. The inner cylinder part 15a and the outer cylinder part 15b are integrally formed at the upper part. The inner cylinder portion 15a has an inner diameter that is substantially the same as the outer diameter of the separator 14, but the outer cylinder portion 15b is formed in a truncated cone shape that gradually increases in diameter from the upper end toward the lower end. The lower end of the outer cylinder portion 15 b is formed long so as to be positioned below the upper surface of the lower electrode body 12.

  The upper electrode body 11, the lower electrode body 12, the protruding needle member 2 and the support member 3 of the lightning protection member 1 are made of a durable and conductive metal such as stainless steel. The lower electrode body 12 is electrically connected to the ground via the support member 3 and a grounding conductor (ground wire) (not shown). Thereby, in the state where this lightning suppression type lightning arrester B is installed vertically, when the ground or a structure is charged with a positive charge due to the influence of thunderclouds or the like, the surface of the upper electrode body 11 is charged with a negative charge. When the structure or the like is charged with a negative charge, the surface of the upper electrode body is designed to be charged with a positive charge. An air hole 12 e is provided at the bottom of the lower electrode body 12.

  The projecting needle member 2 includes a bottomed cylindrical mounting portion 21 and a plurality of projecting needle portions 22 extending radially from the mounting portion 21. In this embodiment, each protruding needle portion 22 is fixed to the outer peripheral surface of the cylindrical mounting portion 21 by welding. An air hole 21e communicating with the air hole 12e is formed at the bottom of the cylindrical mounting portion 21.

  The entire projecting needle member 2 is disposed immediately below the lightning pole member 1 (below the insulator 13). As shown in FIG. 6, the length of the projecting needle portion 22 in the horizontal direction is formed shorter than the radius of the insulating cover 15, so that it does not protrude outward from the outer peripheral surface of the insulating cover 15. Further, the horizontal distance between the tip of the protruding portion 22 and the vertical line (axis line) passing through the center of the lightning pole member 1 is set within five times the height difference from the apex of the lightning pole member 1.

  The support member 3 includes a support rod 31 located at the center and a support pipe 32 arranged coaxially on the outside thereof. The support rod 31 is formed with a male screw 31 a that passes through the attachment portion 21 of the projecting needle member 2 and is screwed into the screw hole 12 d of the lower electrode body 12. The support member 3 is fixed by tightening nuts 33, 33 screwed into the male screw 31a. Therefore, also in this embodiment, as shown in FIG. 6, the axis of the lightning pole member 1, the axis of the needle member 2, and the axis of the support member 3 are configured to be substantially the same axis.

  A pipe flange 34 is provided at the lower part of the support pipe 32, and nuts 35, 35 are screwed into the male screw portion of the support bar 31 penetrating therethrough. The support bar 31 is attached to the attachment plate 37 using the nut 35, the nut 36, and the like.

Also in the lightning suppression type lightning arrester according to this embodiment, the upward discharge current value is reduced by the interaction between the lightning pole member and the tip member, and the lightning strike is sufficiently sufficient for both the summer lightning and the winter lightning. The suppression effect can be enhanced.
Moreover, since the insulating cover 15 is provided outside the cylindrical insulator 13 via the separator 14, the liquid tightness of the insulating portion can also be improved.
Further, since the projecting needle member 2 has a structure in which the projecting needle portion 22 is welded to the bottomed cylindrical mounting portion 21, the structure can be simplified and the manufacturing cost can be reduced.

DESCRIPTION OF SYMBOLS 1 Lightning pole member 11 Upper electrode body 12 Lower electrode body 13 Insulator 14 Separator 15 Insulation cover 2 Needle member 21 Attachment part 22 Needle part 3 Support member 31 Support rod 32 Support pipe A, B Lightning suppression type lightning arrester

Claims (5)

A lightning pole member having an insulator for insulating the upper electrode body from the lower electrode body;
A conductive needle member provided at a lower portion of the lightning pole member;
A support member for supporting the lightning pole member and the needle member ,
The lightning strike suppression lightning arrester, wherein the needle member includes a plurality of needle parts, and each of the needle parts is arranged radially . And the tip of the突針portion, the horizontal distance L between the vertical line passing through the center of the lightning pole member, wherein said is within 5 times the height difference h between the apex of lightning pole member, wherein Item 2. A lightning suppression type lightning arrester according to item 1 . The lightning-suppressing lightning arrester according to claim 1 or 2, wherein the projecting needle member is disposed immediately below the lightning protection pole member. The lightning suppression lightning arrester of Claim 1 or 2 arrange | positioned so that the axis line of the said lightning pole member, the axis line of the said needle member, and the axis line of the said support member may become substantially the same axis line. The lightning-suppressing lightning arrester according to any one of claims 1 to 4 , wherein the lower electrode body and the projecting needle member are grounded via the support member.

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