JPH05121192A - Lightning rod with ring - Google Patents

Abstract

PURPOSE:To expand the protection range of a lightning rod. CONSTITUTION:A horizontal ring portion 1 is fitted at the lower side section of the tip 2 of a bar-like portion A via a conducting support piece so that the angle theta between the bus line of a cone connecting a top point at the tip 2 of a conducting vertical bar-like portion A and the conducting horizontal ring-like portion 1 at the bottom circle and the vertical center line is made 60 deg.-90 deg.. The same lightning protection effect can be obtained with lightning rods having lower height or less number as compared with conventional lightning rods.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning rod which is generally used for protecting ground constructions, livestock, trees and the like from lightning disasters.

[0002]

2. Description of the Related Art Conventionally, a lightning rod installed in a building or the like to prevent damage caused by a lightning strike has a structure in which a needle-like conductive rod-shaped body at the upper end is connected to a grounded copper plate electrode via a down copper wire. In addition, many research and studies have been conducted on the scope of protection, and current Japanese standards require the installation of lightning rods for structures with a height of 20 m or more. The protection angle of the lightning rod is regulated to 60 ° or more for general buildings and 45 ° or more for special buildings intended to store dangerous substances such as flammable substances and explosives.

[0003]

However, in a huge number of buildings, which have been increasing in number in recent years, it is necessary to make the lightning rod attachment position extremely high or to increase the number of installations in order to meet this standard, which increases the cost. Is invited. In order to improve this, it is desired to expand the protection range of the lightning rod, and various attempts including the shape of the tip of the lightning rod have been made, but no clear results have been achieved yet. Under such circumstances, it has been proposed to expand the protection range by a simple method of attaching a horizontal ring near the tip of a normal lightning rod, but the best configuration for that has not been embodied and put into practical use. It has not been done.

Therefore, as a result of earnest experiments and researches, the present inventors cannot necessarily expand the protection range simply by adding a horizontal ring, and there is a certain range of limiting conditions regarding the installation posture of the ring. The present invention has been found to be achieved and the present invention has been completed. That is, the present invention establishes a method of effectively expanding the protection range of the lightning rod by attaching a ring based on these experimental results, and thus provides a safe lightning rod that can be installed generally at a lower cost than conventional products. Is what you are trying to do.

[0005]

The structure of the present invention for achieving the object will be described with reference to FIGS. 1 and 2 corresponding to the embodiments. The lightning rod with a ring of the present invention has a conductive horizontal shape. A lightning rod in which a ring portion (1) and a conductive vertical rod portion (A) penetrating the center of the ring portion are connected via a conductive support piece (6), and the ring portion (1) The ring portion (1) is vertically arranged such that the angle between the generatrix of the cone having the bottom circle as the base circle and the tip (2) of the vertical rod portion (A) as the apex is more than 60 ° and less than 90 °. The tip of the rod-shaped part (A)
(2) It is characterized by being attached to the lower side part.

In this case, if the horizontal ring portion (1) is made of a pipe having a hollow cross section, the load applied to the vertical rod portion (A) can be reduced and the robustness of the attached state is improved, which is preferable. Further, as the support piece (6), for example, if a few spokes are used, the ring can be firmly attached so as to be lightweight and to sufficiently withstand external force such as wind and snow.

[0007]

With the structure of the lightning rod with a ring of the present invention, it is possible to induce lightning to the side ring portion as well, so that the protection range is remarkably expanded as compared with the conventional rod-shaped lightning rod of the same length. It will be.

Therefore, the so-called effective height is higher than that of the conventional lightning rod, and when using the same number of rods, the same protection range as that of the conventional lightning rod can be obtained even if the height is low, and if the height is the same. The protection range equivalent to that of the conventional product can be obtained with a small number.

[0009]

EXAMPLES Examples of the present invention will be described below. FIGS. 1 to 3 show a first example of the present invention, of which FIG. 1 shows the outline of an experimental apparatus.

As the high voltage side electrode (4) simulating a lightning stroke,
A brass rod having a diameter of 10 mm and having a needle tip of 60 ° was used. As the grounding side electrode, a lightning protection electrode (B) with a ring was erected vertically on an aluminum plate electrode (3) simulating the ground surface. The rod-supporting vertical rod-shaped portion (A) of the lightning protection electrode (B) with a ring is a brass round rod having a diameter of 5 mm, and the tip (2) thereof is used as a needle of 60 °, and the ring portion (1) is used. Is a brass cylinder with a diameter of 5 mm and a diameter of 80 mm.
A curved body was used. The height of the vertical rod portion (A) on the flat plate electrode (3) was 10 cm.

The ring lightning protection electrode (B) was attached to the ring at a position 1 cm below the tip (2) of the vertical rod (A). As a result, as shown in FIG. 2C, the ring angle (θ) became 76 °.

The output voltage waveform of the shock voltage generator (5) used is a standard lightning impulse (1.4 / 42.5 microseconds).
The applied voltage and the distance between the electrodes (the distance between the tip of the high-voltage needle electrode and the flat plate electrode) were 295 kV and 40 cm when the positive voltage was applied, and 390 kV and 20 cm when the negative voltage was applied.

Using the above experimental apparatus, in order to simulate a lightning strike penetration path that changes in various ways, the high-voltage side needle electrode is moved horizontally as shown by the broken line in FIG. The spark discharge path generated by applying multiple times to the camera was photographed by using a camera equipped with a multiple exposure mechanism. As a result, we investigated what the passing area and non-passing area (protection range of the lightning protection electrode) of the spark discharge path would be. The result was as shown in FIG.

In the second embodiment shown in FIG. 2B, the ring portion (1) of the lightning protection electrode with ring (B) is mounted at a position 2 cm below the tip (2) of the vertical rod portion (A). The conditions were the same as in Example 1 except that the ring angle (θ) was 63 °. The result was as shown in FIG.

In Comparative Example 1 shown in FIG. 2 (a), the mounting position of the ring portion (1) of the lightning protection electrode (B) is changed to the vertical rod portion (A).
The conditions are the same as those in Examples 1 and 2 except that the ring angle (θ) is set to 45 ° by making the portion 4 cm below the tip (2). The result is shown in FIG.

In Comparative Example 2, as a model of a normal lightning rod without a ring, only a vertical rod portion (A) was erected in place of the lightning rod electrode with a ring (B), and otherwise the same as in Examples 1 and 2. It is a condition. The result is shown in FIG.

The tip (2) of the vertical rod portion (A) for supporting the ring
The angle formed by the line connecting the above and the spark return point closest to the lightning protection electrode with respect to the vertical line is regarded as the protection angle of the lightning protection electrode, and the results of FIGS. 3 to 6 obtained above are summarized in Table 1. It became a street. It can be seen from Table 1 that the protection angle of the lightning protection electrode is always larger when the negative voltage is applied than when the positive voltage is applied. Further, as is clear by comparing Example 1 having a ring angle (θ) of 76 ° and Example 2 having a ring angle (θ) of 63 ° with Comparative Example 2 without a ring, it is clear whether the applied polarity is positive or negative. Instead, the protection angle of the lightning protection electrode is increased by attaching the ring. On the other hand, the ring angle (θ) is 45 °
Comparing Comparative Example 1 with Comparative Example 2 without a ring, it was confirmed that the protection angle of the lightning protection electrode was decreased conversely by the attachment of the ring when the positive voltage was applied. This shows that the protection range of the lightning rod is not expanded simply by mounting the ring, regardless of the polarity of the applied polarity and the size of the ring angle (θ).

[0018]

[Table 1]

The reason why such a result is obtained has not been completely clarified yet, but if the ring exists within 60 ° which is the protection angle of the vertical electrode for supporting the ring, the function of the ring is meaningless. On the contrary, when the ring exists outside the protection angle of 60 ° created by the electrode, it is shown that the function of increasing the protection angle of the lightning protection electrode occurs regardless of the polarity of the applied voltage. ing. Also, the ring angle is 9
If the ring is installed in a position that exceeds 0 °, the electric field shielding effect of the ring itself diminishes the effect of attracting the discharge path of the vertical rod portion with a sharp tip, so the protection range of the entire lightning protection electrode is rather narrow. Therefore, it is not preferable.

As described above, in order to effectively increase the protection angle of the lightning protection electrode, that is, the protection range, it is important to set the ring mounting posture, that is, the ring angle. According to the above-mentioned experimental results of the present inventors. When the ring angle (θ) is 60 ° or more and less than 90 °, it is apparent that the protection range of the entire lightning protection electrode can be increased together with the protection range of the sharp vertical rod-shaped portion (electrode).

Although the embodiments considered to be typical of the present invention have been described above, the present invention is not necessarily limited to the structures of these embodiments, and has the above-mentioned constitutional requirements referred to in the present invention, and The present invention can be carried out by appropriately modifying it within a range that achieves the object of the present invention and has the following effects.

[0022]

As is apparent from the above description, the present invention significantly expands the protection range of the lightning rod by attaching the conductive horizontal ring portion to the conventional rod-shaped portion of the lightning rod. , Compared to conventional lightning rods,
If the same number is used, it is of low height, and if the same height is used, the same lightning protection effect can be obtained with a small number of rods, resulting in easy installation work and maintenance management of lightning rods, and installation and maintenance. It has come to have a remarkable effect that the cost can be significantly reduced, which cannot be expected with the conventional one.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an experimental device according to an embodiment of the present invention.

FIG. 2 is a perspective view showing details of main parts of the apparatus shown in FIG.

FIG. 3 is a front view schematically showing a photograph of a spark discharge path taken in Example 1.

FIG. 4 is a front view schematically showing a photograph of a spark discharge path taken in Example 2.

FIG. 5 is a front view schematically showing a photograph of a spark discharge path taken in Comparative Example 1.

6 is a front view schematically showing a photograph of a spark discharge path taken in Comparative Example 2. FIG.

[Explanation of symbols]

 (1) Horizontal ring part (2) Tip of vertical bar part (3) Ground side plate electrode (4) High voltage side needle electrode (5) Impact voltage generator (A) Vertical bar part (B) Lightning rod electrode with ring

Claims (1)

[Claims] 1. A conductive horizontal ring portion (1) and a conductive vertical rod portion (A) located at the center of the ring portion are connected via a conductive support piece (6). A lightning rod, with the ring (1) as the bottom circle and the tip of the vertical rod (A)
The ring portion so that the angle between the generatrix of the cone having (2) as its apex and the vertical centerline is 60 ° or more and less than 90 °.
A lightning rod with a ring, wherein (1) is attached to a portion of the vertical rod portion (A) near the tip (2).