JP2004220903A - Lightning conductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting conductor device avoiding damage caused by electric shock exceeding the quality of design of an insulating cable constituting the lighting conductor device, safely surely treating excessively high current, and having simple structure, a low price, and high reliability. <P>SOLUTION: The lighting conductor device is equipped with a lighting conductor 4, an insulator 3 insulating and supporting the lighting conductor, a base support 2 supporting the insulator 3, and an insulating cable C in which one end is connected to the lighting conductor and the other end is connected to a ground plate 5 buried in the ground, and arcing horn members 8, 8' having discharger gaps 81, 81' discharging at designed impulse with stand voltage or less of the insulating cable are installed between the lighting conductor and the base support. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lightning rod device for protecting a building or a facility installed in a building including a communication facility from a lightning surge such as a lightning strike.
[0002]
[Prior art]
Conventionally, a lightning rod, an insulator made of an insulator for insulating the lightning rod, a long high-insulation resin, etc., and a support such as a steel tower or a column supporting and mounting the lightning rod via the insulator, are connected to the lightning rod. There is known a lightning rod device disposed in a wireless relay station or the like, which is composed of a highly insulated insulated cable and a grounding body connected to the insulated cable.
[0003]
In a conventional lightning rod device, if the electric shock is less than the impulse withstand voltage, which is the design characteristic (design quality) of a highly insulated cable, the electric shock will be absorbed by the grounding body via the insulated cable. Therefore, it is possible to protect communication equipment such as a radio relay station from electric shock and to ensure normal communication, but if a lightning rod receives an electric shock of design quality that exceeds the expected level, a highly insulated cable will Insufficient resistance to electrical breakdown may cause the lightning rod to lose its function, increase the ground potential around the building of the wireless relay station, and damage communication equipment.
[0004]
As shown in FIG. 4, the applicant assigns a conductor (center conductor) c1, an inner semiconductor layer c2 on the outer periphery of the center conductor c1, and an insulating layer c3 on the outer periphery of the inner semiconductor layer c2. An external semiconductor layer c4 is provided on the outer periphery of the insulating layer c3, a copper tape shielding layer (external conductor) c5 is provided on the outer periphery of the external semiconductor layer c4, and a semiconductive pressing tape layer c6 is provided on the outer periphery of the external conductor c5. A highly insulated insulated cable C is proposed (for example, Japanese Patent Laid-Open No. 2001-23793), which has a configuration in which a semiconductive sheath layer c7 is disposed on the outer periphery of the pressure-resisting tape layer c6, and a predetermined effect is obtained. . However, even if the performance is normally sufficiently satisfied, the natural current situation due to weather fluctuations or the like may cause electric shock of a scale exceeding the design quality of the insulated cable C, which exceeds the design quality of such an insulated cable C. In order to avoid as much as possible the major disruption of communication lines due to electrical shocks of scale, as well as to maintain and improve reliability, electrical shocks exceeding the design quality of the above-mentioned highly insulated cable C There is a need for a lightning rod device that can withstand.
[0005]
[Problems to be solved by the invention]
By the way, when connecting the lightning rod to the insulated cable C, the layers c2 to c7 of the insulated cable C are peeled to expose the central conductor c1, and the central conductor c1 is connected to the lightning rod, and the insulation cable C is terminated. However, even if there is no problem with the high-insulation cable C itself, this terminal processing portion reduces the impulse withstand voltage and damages the high-insulation cable C, that is, high insulation. The insulation layer c3 between the center conductor c1 and the outer conductor c5 of the insulated cable C is broken down, and an electric shock current flows into the ground via the outer conductor c5, raises the ground potential, and the function of the lightning rod device is lost. Had the problem.
[0006]
The impulse withstand voltage of the insulation cable of the lightning rod device is 250 KV to 500 KV or less. For example, if the electric shock current is 30 KA and the ground resistance value of the grounding body is 30 ohms, the impulse voltage of 900 KV is applied to the insulation cable through the lightning rod. Since it is applied to damage the insulated cable, the ground resistance value of the grounding body is lowered to make the lightning rod device have a predetermined design impulse withstand voltage.
[0007]
However, if the lightning rod device receives an electrical shock that is higher than the design quality, highly insulated cables (especially, the cable separation part of the connection with the lightning rod) will be damaged, losing the function as a lightning rod and protecting communication equipment, etc. The problem of not being able to occur will occur.
[0008]
An object of the present invention is to solve the problem of damage to the connection portion between a lightning rod and a high-insulation insulated cable, which the above-described conventional lightning rod device has, and to provide a large-scale electric shock exceeding the design voltage of the insulated cable. Even when a lightning rod is applied to the lightning rod device, it is possible to safely discharge the electric shock current to the ground, to reliably protect communication equipment, etc., and to communicate safely and reliably for the next electric shock. An object of the present invention is to provide a lightning rod device capable of protecting equipment and the like.
[0009]
[Means for Solving the Problems]
In order to achieve the above-mentioned object, the present invention provides a lightning rod, an insulator for insulatingly supporting the lightning rod, a base support for supporting the insulator, one end connected to the lightning rod and the other end In a lightning rod device having an insulation cable connected to a grounding body embedded in the ground, a discharge gap is provided between the lightning rod and the base support so as to perform a discharge operation at a voltage lower than a design impulse withstand voltage of the insulation cable. An arc horn member is provided.
[0010]
【Example】
Hereinafter, examples of the present invention will be described. However, the present invention is not limited to these examples as long as the gist of the present invention is not exceeded.
[0011]
Reference numeral 1 denotes a support member such as a steel tower or a column installed in a concrete pedestal or a building B, 2 denotes a base support member standing on the upper part of the support member 1, and 3 denotes an upper part of the base support member. 4 is a lightning rod disposed on the top of the insulator 3. The lightning rod 4 has a generally needle-shaped lightning rod 41 located at the tip, a substantially truncated cone-shaped intermediate portion 42 connected to the lower end of the lightning rod 41, and a substantially cylindrical shape connected to the lower end of the intermediate portion 42. And a base 43. In the embodiment shown in FIG. 2, the insulator 3 is configured as an insulator 31 having a high insulating property.
[0012]
Reference numeral 5 denotes a low-resistance grounding body that discharges the lightning current of the lightning rod 4 to the ground 6, and the grounding body 5 is connected to the insulated cable C having the above-described configuration that is insulated and pulled down by the support member 1. Yes. The grounding body 5 is embedded in a vertical hole formed in the depth direction of the ground 6 to such a depth that the ground surface 61 of the ground 6 can be suppressed to a predetermined potential or less. The insulated cable C may be peeled over a predetermined length to expose the center conductor c1, and the exposed center conductor c1 may be used as the grounding body 5. Alternatively, the grounding body 5 may be separately constructed to form the insulated cable C. The structure connected to may be sufficient. The grounding body 5 is not limited to being embedded in a vertical hole formed in the depth direction of the ground 6, but can be embedded in a horizontal groove formed along the ground surface 61. In addition, 7 is an insulation process part of the insulated cable C embed | buried in the vertical hole of the earth 6, and has a function which suppresses the electric potential which appears in the ground surface 61. FIG.
[0013]
The upper end portion of the insulated cable C arranged along the support member 1 is peeled off over a predetermined length to expose the central conductor c1, and the central conductor c1 is formed in a substantially frustoconical shape of the lightning rod 4. While being connected to the connection terminal 44 provided in the intermediate part 42, the upper end part of the insulated cable C is appropriately subjected to cable terminal processing. Note that A is an antenna device disposed at an appropriate position of the support member 1.
[0014]
Reference numeral 8 denotes an arc horn member constituted by a lower arc horn 8a and an upper arc horn 8b arranged via an insulator 3, and a discharge gap 81 is provided between the lower arc horn 8a and the upper arc horn 8b. Is formed. When the insulator 3 is the insulator 31, the lower arc horn 8 a is attached so as to be sandwiched between the base support 2 and the insulator 3, and the upper arc horn 8 b is connected to the lightning rod 4. It is attached so as to be sandwiched between the base 43 and the insulator 3. Further, the gap length of the discharge gap 81 is configured such that the discharge voltage of the discharge gap 81 starts to discharge with an electric shock voltage that is equal to or lower than the impulse withstand voltage of the insulated cable C.
[0015]
In the lightning rod device described above, when the lightning rod 4 receives an electric shock less than the design impulse withstand voltage (design quality) of the insulated cable C constituting the lightning rod device, the lightning current flows from the lightning rod 4 to the insulated cable C. , And is absorbed through the grounding body 5 connected to the insulated cable C. As a result, the lightning rod device including the insulated cable C is not damaged, the communication device and the like are protected, and normal communication can be performed.
[0016]
Next, when the lightning rod 4 receives a high electric shock exceeding the design impulse withstand voltage (design quality) of the insulated cable C constituting the lightning rod device, the electric shock current flows to the grounding body 5 through the insulated cable C. At the same time, the discharge gap 81 between the lower arc horn 8a and the upper arc horn 8b of the arc horn member 8 discharges to constitute a bypass discharge circuit, and a part of the electric shock current is supported by the base support 2 or the support. Since it flows to the bypass discharge circuit which passes through the member 1 and is absorbed by the ground 6, the current flowing through the insulated cable C can be suppressed and damage to the insulated cable C can be prevented. Can be processed, and communication equipment and the like are protected, and normal communication can be performed.
[0017]
The embodiment shown in FIG. 3 shows an example in which the insulator 3 is configured as an insulating resin tube 32 such as a long reinforced plastic having high insulation and high strength. The insulating resin tube 32 is configured such that the upper end portion thereof is inserted into and fixed to the mounting tube 9 disposed at the lower end of the lightning rod 4. The insulating resin pipe 32 itself is attached to the base support body 2 and the support member 1 by an appropriate mounting bracket 10. The insulated cable C is inserted into the insulated resin tube 32, and the central conductor c1 exposed at the end of the insulated cable C is connected to the lightning rod 4 via the connection terminal 11 provided on the mounting tube 9. Connected and terminal processing is performed.
[0018]
8 ′ is a rod-shaped arc horn member attached to the mounting bracket 10, and a discharge occurs between the tip of the arc horn member 8 ′ and the lower end 91 of the mounting tube 9 attached to the lower end of the lightning rod 4. A gap 81 'is formed. Further, the gap length of the discharge gap 81 ′ is configured such that the discharge voltage of the discharge gap 81 ′ starts to discharge with an electric shock voltage equal to or lower than the impulse withstand voltage of the insulated cable C, as described above. Has been. The discharge operation of the rod-shaped arc horn member 8 'when the lightning rod 4 receives a high electric shock exceeding the design impulse withstand voltage (design quality) of the insulated cable C constituting the lightning rod device is also shown in FIG. The description is omitted because it is similar to the embodiment described.
[0019]
As described above, the arc horn members 8 and 8 ′ having the discharge gaps 81 and 81 ′ that perform the discharge operation below the design quality of the insulated cable C constituting the lightning rod device are arranged between the lightning rod 4 and the base support 2. When the lightning strike received by the lightning rod 4 is normal, the lightning current is absorbed by the ground 6 through the insulated cable C and the grounding body 5, and the lightning rod 4 constitutes the lightning rod device. When an excessive electric shock higher than the design quality of the insulated cable C is received, the discharge gaps 81 and 81 'are discharged, and a part of the electric shock current passes through the base support 2 and the support member 1 and is grounded. 6 is constructed so as to flow through the bypass circuit absorbed by the electric shock absorber 6, so that it is possible to safely handle the overcurrent due to the electric shock safely, and the structure is simple, inexpensive, and excellent in reliability. Can provide That.
[0020]
The high-insulation cable is not limited to the above-described insulation cable C, and an insulation cable having another configuration can be used as long as the center conductor c1 and the outer conductor c5 have a predetermined insulation impulse withstand voltage. You can also Reference numeral 12 denotes an insulated cable holding fitting for holding the insulated cable C attached to the base support 2.
[0021]
【The invention's effect】
Since this invention is comprised as mentioned above, there can exist the effect described below.
[0022]
Since an arc horn member having a discharge gap that discharges below the design impulse withstand voltage of the insulated cable is arranged between the lightning rod and the base support, damage due to electric shock exceeding the design quality of the insulated cable constituting the lightning rod device In addition, it is possible to safely and reliably handle an excessive current due to electric shock, and to provide a lightning rod device that is simple in structure, inexpensive, and excellent in reliability.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a lightning rod device as one embodiment of the present invention.
FIG. 2 is an enlarged view of a main part of the lightning rod device shown in FIG.
FIG. 3 is an enlarged view of a main part of a lightning rod device according to another embodiment of the present invention.
FIG. 4 is a cross-sectional view of an insulated cable constituting the lightning rod device of the present invention.
[Explanation of symbols]
C ... Insulated cable 1 ... Support member 2 ... Base support 3 ... ... Insulator 4 ... Lightning rod 5 ... Grounding body 6 ... Earth 8, 8 '... Arc horn members 81, 81' ... Discharge gap

Claims (1)

A lightning rod, an insulator for insulatingly supporting the lightning rod, a base support for supporting the insulator, and one end connected to the lightning rod and the other end connected to a grounding body embedded in the ground. In a lightning rod device having an insulated cable, an arc horn member having a discharge gap that performs a discharge operation at a voltage equal to or lower than a design impulse withstand voltage of the insulated cable is disposed between the lightning rod and the base support. apparatus.

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