JP3032754U - A lightning rod with the projecting needle and the pull-down insulated wire electrically insulated from the non-magnetic metal support tube - Google Patents

Abstract

(57) [Abstract] [Problem] In recent years, many vulnerable electronic devices have been installed in buildings, and the weak electric devices and signal lines are subject to induced voltage and There are many cases of failure due to the potential difference. SOLUTION: A non-magnetic metal supporting tube D is used, and an insulating bushing B is firmly attached to the tip of the metal supporting tube D. A hole 4 penetrating the center of the insulating bushing B and a protruding needle portion in the metal supporting tube D. A lightning rod structure in which A and the pull-down insulated electric wire F are fixed and mechanically integrated, but electrically insulated.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 In the present invention, the electric circuit of the lightning rod, which has been conventionally gone unnoticed, is made independent, and the projecting needle and the pull-down wire that can reasonably guide the lightning current directly to the ground are electrically insulated from the support tube. Regarding the lightning rod.

[0002]

[Prior art]

 The installation of lightning rods is obligatory for buildings over 20 m in height according to the Building Standards Law, and they are constructed according to the provisions of Japanese Industrial Standard JIS A 4201.

However, this regulation aims at protecting a building from a lightning disaster, and this lightning rod is sufficiently useful for that purpose. However, in recent years, due to the remarkable arrival of electronic equipment, OA and FA have become remarkably widespread inside buildings. Therefore, regardless of the lightning rod constructed in accordance with JIS, accidents of electronic equipment due to lightning are increasing.

[0004]

[Problems to be solved by the invention]

 Conventionally, reinforced concrete or reinforced concrete buildings are entirely covered with reinforcing bars and steel frames, and the entire building is in the form of a metal cage, which is considered to be the same as a “Faraday cage”. It has been thought that no voltage is generated inside the building. However, the principle of "Faraday cage" that Faraday found is based on the electrostatic viewpoint as shown in Fig. 1. That is, in the case of FIG. 1, no current flows in the conductors of the cage, and therefore, when all the conductors have the same potential, no electric field is generated inside even if the cage becomes a high voltage with respect to the ground. That's what it means. However, when this is applied to lightning protection, a lightning current flows through the conductors that compose the cage, so a potential difference occurs between the conductors due to the impedance drop, and an electric field is generated inside the cage. Normally, this value is not dangerous to the human body, but in some cases it cannot be ignored for electronic devices containing many semiconductor elements. If the resistance of the conductor is high (the conductors are thin or the connections between them are imperfect), the electric field value becomes even higher. If the protected object is electrically bridged between two points in the cage (referring to the cable wire connected to the computer, etc.), the protected object will be damaged due to the potential difference.

Further, in a building, there are places where a large number of cables housed in a cable rack stand up along a wall or places where important electronic devices are installed, and if a lightning current flows near them, , Electromagnetic induction may cause surge voltage on cables and important electronic devices. On the other hand, the installation of lightning arresters for low-voltage power supplies and lightning arresters for low-voltage circuits is gradually becoming popular in order to protect the internal equipment of buildings from lightning.However, especially in signal circuits, there are problems such as functional impact on protection equipment. In some cases, a lightning arrester cannot be installed.

For the above reasons, it is important that the lightning current does not flow through the structure even when a lightning rod strikes. Therefore, there is a demand for a lightning rod that has both mechanical strength to withstand strong wind power and an electrical function that directly guides it to the ground (foundation of the building) by using a down conductor that insulates lightning current. In the past, there was a feeling that mechanical aspects were more important and electrical functions were neglected.

[0007]

[Means for Solving the Problems]

 In view of the above situation, the present invention has a through hole in the longitudinal direction at the center, and has a head with a large diameter, a fitting portion, and a leg with a small diameter, and the head has Prepare an insulating bushing in which non-penetrating female screws are embedded in three directions from the side for the female thread that has penetrated and the mating section, and then separately prepare the mating section of the insulating bushing to which adhesive is applied. The upper, lower, middle and lower three steps are pushed in from above the metallic connecting tube having screw holes drilled in three directions, and the metallic connecting tube is screwed in the upper three directions of the connecting tube in the three directions of the insulating bushing fitting portion. Connect the pull-down insulation wire of a certain length to the screw hole, and then connect the pull-down insulation wire of a fixed length from below the leg center hole of the insulating bushing to hide the connection portion of the pull-down insulation wire. Insert it all the way down to seat it, and tighten the fixing push bolt to the through-thread female screw on the head of the insulating bushing. Attach the insulating bushing to the pull-down insulated wire-attached protruding needle, and cover it from above with a non-magnetic metal support tube having screw holes drilled in two steps in three directions in advance at the tip, The connecting pipe made of metal and the non-magnetic metal supporting pipe are aligned and screwed together with the connecting screw to mechanically and firmly integrate the projecting needle, the pull-down insulated wire and the non-magnetic metal supporting pipe. Electrically, there is provided a lightning rod in which the projecting needle and the pull-down insulated wire are electrically insulated from the non-magnetic metal supporting tube.

[0008]

[Embodiment of the invention]

 The present invention will be described in detail with reference to FIGS. 2 to 6, which is a most preferable embodiment of the lightning rod in which the projecting needle and the pull-down wire are electrically insulated from the support tube.

[0009] (A) is a needle portion that meets the requirements of Japanese Industrial Standard JIS A 4201. More specifically, the protruding needle portion (A) is, for example, a copper (including copper alloy) rod having a diameter of 12 mm or more, and includes an exposed portion (1), a concealed portion (2), and a connecting portion (3). The exposed portion (1) is on the upper side of the projecting needle portion (A) and has a sharpened tip so as to promote tip discharge, and is plated with gold (1a) to prevent rust. Further, the length of the exposed portion (1) is targeted to be twice as long as that of a commercially available lightning rod, but the length is kept at least 30 cm or more. The reason for this is to increase the electric field strength at the tip, and to prevent accidental lightning strikes on the support tube (D). The connection portion (3) is connected to a connector (E) described later by brazing with brass.

Reference numeral B is an insulating bushing, and this insulating bushing (B) is composed of a semi-exposed type porcelain having a through hole (4) and a leg (5a) in the central longitudinal direction. (A) and the connector (E) and a part of the pull-down insulated wire (F) connected to it are electrically insulated from the lightning rod support tube (D), and the support tube (D) is It has to serve as a mechanical and solid connection. Further, the concealed portion (2) of the projecting needle portion (A) is inserted and held in the through hole (4) of the insulating bushing (B). Also, in order to prevent rainwater from entering the through hole (4) from the root of the exposed portion (1) of the needle part (A) and to replace the needle part (A) relatively easily, Need to consider. On the head (5) of the insulating bushing (B), a brass cap (6) filled with caulking agent such as silicone is fitted at the base of the exposed portion (1) and attached by a screw to cover it. . Furthermore, the concealed portion (2) of the projecting needle portion (A) inserted in the through hole (4) by embedding the female screw (7) in three directions on the upper side of the insulating bushing (B) is in three directions. It is tightened with bolts (8) and fixed to the insulating bushing (B). Further, the insulating bushing (B) is provided with a plurality of draining-type concave-convex portions (9), (9a), (9b), ... For lengthening the leakage path. (10) is a fitting portion provided on the lower side of the insulating bushing (B) for fitting with an upper portion of a connecting pipe (C) described later, and a female portion necessary for fastening the connecting pipe (C) made of metal in advance there. The screw (11) is embedded on three sides, and the fitting portion (10) of the insulating bushing (B) is coated with an adhesive and inserted into the connecting pipe (C) to insert the fitting portion. Hold (10) from the three sides with the fixing bolts (12) that are held and screwed into the female screw (11) to fix.

The connection pipe (C) is a processed brass pipe or the like, and is a component for connecting the insulating bushing (B) or the like to a support pipe (D) described later. It comprises a holding part (13) fitted to (10) and a mounting part (14) for fitting and mounting the support tube (D). Since the lightning rod is placed on a high place such as the rooftop of a building, it is designed so that the root part of the insulating bushing (B) does not break due to wind pressure. The fixing bolt (in advance) is attached to the tip mounting part of the support pipe (D). Screws (16) for tightening 15) are provided at three locations on three sides, and the support pipe (D) inserted into the connecting pipe (C) is fixed by tightening.

Since the supporting tube (D) has a structure in which an insulated wire must be inserted inside, a counter electromotive force is generated due to a lightning current (resulting in an increase in impedance of the down conductor). To prevent this, non-magnetic metal brass tubes and aluminum tubes are used. The support tube (D) is inserted into the connecting tube (C) together with the seat plate (21), and then the fixing bolt (15) is used. Then, tighten and fix at 6 points from 3 directions. In order to facilitate the work of attaching and detaching the projecting needle (A) to the support tube (D), an opening (17) is provided near the base of the support tube (D), and this opening (17) is It is covered with a blind lid (18) with screws or the like.

(E) is the connector made of copper or the like for connecting the projecting needle (A) and the pull-down insulated wire (F). This connector (E) is provided with an insertion port (19) for the pull-down insulated wire (F) at the opposite end connected by brass brazing to the lower end connection part (3) of the protruding needle (A). The pull-down insulation wire (F) inserted in (19) is pressed by a screw (20) and then connected by soldering or the like. Attach the connection terminals to the lower end of the down wire (F) and the insulated wire rising from the ground, tighten the screws between them to connect them, and carefully cover the connection points with insulating tape or the like to insulate them from the support tube. To do.

[0014]

[Effect of the invention]

 By effectively separating the electrical circuit of the lightning rod, which has rarely been neglected in the past, when the lightning rod operates due to a lightning strike, the lightning current is pulled down from the spike part and through the conducting wire to the ground (foundation of the building). ), And the problem of flowing into the structure through the support tube of the lightning rod was resolved. Moreover, the support tube of the lightning rod can be firmly attached by using the structure of the building as in the past. The lead wire down to the ground (foundation of the building) is put in a vinyl pipe and pulled down along the outer wall of the building or embedded in a building pillar and pulled down. The end of the lead wire is the foundation part of the building. Electrically connected to the structure. As described above, since the lightning current does not flow through the structure inside the building, there is an effect that the internal electronic devices are not adversely affected by induction or potential difference.

[Brief description of the drawings]

FIG. 1 is a principle view of a Faraday cage.

FIG. 2 is a partial cross-sectional view of a part of a lightning rod.

FIG. 3 is a perspective view of a protruding needle portion.

FIG. 4 is an enlarged perspective view of an insulating bushing portion.

FIG. 5 is an enlarged perspective view of a cap that prevents rainwater between the insulating bushing and the needle portion.

FIG. 6 is an enlarged perspective view of a connecting device between a projecting needle portion and a down conductor.

[Explanation of symbols]

 A Projection part B Insulation bushing C Metal connection tube D Non-magnetic support tube E Connector between projecting needle part and pull-down insulation wire F Insulation pull-down wire 1 Exposed part 1a Plating part 2 Concealed part 3 Connection part 4 Through hole 5 Head 5a Leg 6 Cap 7,11 Female screw 8,12,15 Fixing bolt 9,9a, ... Concavo-convex part 10 Fitting part 13 Holding part 14 Attachment part 16 Screw 17 Opening part 18 Blind lid 19 Inserting port 20 screw 21 seat plate

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[Procedure amendment]

[Submission date] August 27, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims for utility model registration

[Correction method] Change

[Correction contents]

[Utility model registration claims]

Claims (5)

[Utility model registration claims] 1. A vertical through hole is formed at the center, which is composed of a large-diameter head, a fitting portion, and a small-diameter leg portion. An insulating bushing in which a penetrating female screw is embedded in three directions from the side is prepared, and then a fitting portion of the insulating bushing coated with an adhesive is separately prepared. Is pushed in from above the metal connecting pipe that is drilled, and the upper three-direction screw holes of the metal connecting pipe are screwed into the insulating bushing fitting portion in accordance with the three-direction screw holes, Next, insert a protruding needle to which a pull-down insulating wire of a certain length is connected from below the leg center hole of the insulating bushing until the connecting portion of the pull-down insulating wire is hidden, and then sit down to seat the insulating bushing head. Tighten the fixing push bolt to the penetrating female screw of the The fitting with the shacking is put on the non-magnetic metal supporting tube having screw holes at the tip thereof in advance in two steps and in three directions from above, and each of the metal connecting tube and the non-magnetic metal supporting tube is attached. Align the screw holes and screw them together with the connecting screw to mechanically and firmly integrate the projecting needle, the pull-down insulating wire and the non-magnetic metal support tube, and electrically connect the projecting needle and the pull-down insulating wire to the non-magnetic body. A lightning rod electrically insulated from the metal support tube. 2. The exposed portion of the projecting needle according to claim 1 has a length longer than 30 cm. 3. The insulating bushing according to claim 1 is a porcelain product having a plurality of draining-type concavo-convex portions on its surface in order to extend the leakage path of the insulator. 4. A metal cap that can be filled with a caulking agent such as silicon is fitted in close contact with the root of the exposed portion of the projecting needle described in claim 1, and is fixed by a screw. 5. An opening covered with a blind lid is provided near the base of the support tube according to claim 1 in consideration of workability.