JPH05315048A - Gas-filled lighting tube - Google Patents

Abstract

PURPOSE:To provide a gas-filled lightning tube wherein each function can be sufficiently displayed of a fail safe mechanism and a vent safe mechanism. CONSTITUTION:In a gas-filled lightning tube wherein insulators 11, 11 are interposed to arrange line electrodes 12, 12 and an earth electrode 14 opposed to each other, an insulating film 20, composed of heat resisting material of polyimide resin or mica and the like provided with a small hole group formed of many small holes 24 in a part positioned on surfaces of the line electrodes 12, 12, is mounted over between the line electrodes 12, 12 and the earth electrode 14 and further interposed between a conductive leaf spring 60 electrically connected to the earth electrode 14 and the line electrodes 12, 12. Metal thin plates 40, 40, composed of low melting point metal of solder, tin, etc., melted at a temperature lower than the decomposing or softening temperature of the heat resisting material, of which the insulating film 20 is formed, and further deformable along peripheral surfaces of the line electrodes 12, 12, are interposed between the insulating material 20 on the line electrodes 12, 12 and the conductive leaf spring 60 or between the line electrodes 12, 12 and the insulating film 20.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas arrester,
More specifically, the present invention relates to a gas arrester provided with a fail-safe mechanism and a vent-safe mechanism.

[0002]

2. Description of the Related Art A lightning arrester 200 shown in FIG. 9 is used to protect communication equipment from external surges such as lightning on communication wires such as telephone lines.
Is installed. As shown in FIG. 10, the lightning arrester 200 is filled with an inert gas such as argon and has an insulator 21.
The arrester body 220 in which the line electrodes 206, 206 and the ground electrode 208 are arranged via the 0, 210 is often used. By the way, commercial power lines (AC100
When a situation in which V, 200 V, 6600 V) continuously contacts (mixed lines) occurs, a high voltage is continuously applied to the arrester body 220, and a discharge is continuously generated in the arrester body 220. The lightning arrester 200 may be overheated and may cause a disaster such as a fire.

In order to prevent such overheating of the lightning arrester 200, as shown in FIG. 10, the lightning arrester main body 220 has a conductive leaf spring 202 mounted on the outer peripheral surface of the lightning arrester main body 220 and the lightning arrester main body. A so-called fail-safe mechanism in which an insulating film 204 made of a thermoplastic resin such as polyester is sandwiched between 220 and 220 is provided. According to the arrester 200 provided with such a fail-safe mechanism, when the arrester 200 is overheated due to continuous application of high voltage and continuous discharge in the arrester body 220, a thermoplastic resin is used. Insulating film 204 composed of arrester body 220
The conductive leaf spring 202 that has been melted by the heat of and has pressed the line electrodes 206, 206 and the ground electrode 208 is electrically connected to the line electrodes 206, 206 and the ground electrode 208. For this reason, the ground electrode 208 and the line electrodes 206, 206 are electrically connected, and continuous discharge in the arrester body 220 is stopped, so that a fire or the like due to overheating of the arrester 200 can be prevented.

However, the arrester 200 having only the fail-safe mechanism shown in FIGS. 9 to 10 is the arrester body 22.
When an inert gas such as argon filled in 0 scatters for some reason, even if an external surge is applied to the arrester 200, discharge in the arrester main body 220 is unlikely to occur, and communication devices, etc. The device body may be damaged. For this reason,
JP-A-53-52961 (US Pat. No. 42120)
(Specification No. 47), a lightning arrester provided with the vent-safe mechanism shown in FIG. 7 is proposed. This arrester
A conductive leaf spring 2 electrically connected to the ground electrode 208
02 and line electrodes 206, 206 sandwiching slits 21 in each of insulating films 204a, 204b sandwiched between them.
2, 212 are formed. Such slits 212,
By 212, as shown in FIG.
A space corresponding to the thickness of the insulating films 204a and 204b can be formed between and the line electrodes 206 and 206.

Further, the present inventor has previously proposed Japanese Patent Application No. 58-220.
Like the lightning arrester shown in FIG. 5 proposed in the specification of No. 672 (Japanese Patent Publication No. 2-3274), the conductive leaf spring 12 is used.
By forming a small hole group in which a large number of small holes 114 are formed in a portion in contact with the line electrodes 104, 104 in the insulating film 110 sandwiched between 0 and the outer peripheral surface of the arrester body 100, A vent safe mechanism can be provided. In the arrester shown in FIG. 5, a conductive leaf spring 120 having a valley formed in the center and a mountain-shaped cross section is spot-welded to the surface of the ground electrode 106 of the arrester 100 through the slit 112 of the insulating film 110. And the insulating film 110 is connected by both ends of the conductive leaf spring 120.
The portion of the small hole group formed on the line electrodes 104, 104
It is pressed against the surface.

[0006]

According to the lightning arrester shown in FIGS. 7 to 8 and 5, both the fail-safe mechanism and the vent-safe mechanism can be provided. That is, the lightning arrester is provided by continuous discharge in the arrester body. When the main body is heated, the insulating film made of thermoplastic resin is melted, and the conductive leaf spring electrically connects the line electrode and the ground electrode to stop the continuous discharge, thereby preventing a fire or the like. Occurrence can be prevented. In addition, if an inert gas such as argon filled in the arrester body scatters and discharge within the arrester body becomes difficult to occur, if an external surge is applied to the arrester, the top surface of the line electrode In the space formed by the slit 212 (FIG. 8) or the small hole 114 (FIG. 5) located at, the discharge can be induced between the line electrode and the conductive leaf spring.

However, in the lightning arrester shown in FIGS. 7 to 8, it is extremely difficult to bend the conductive leaf spring 202 so as to be parallel to the outer peripheral surface of the lightning arrester main body 220. The spatial distance between the outer peripheral surface of the tube body 220 and the conductive leaf spring 202 differs depending on the location. For this reason,
The discharge start voltage and the like differ depending on the position within the same slit, and the function of the vent safe mechanism cannot be fully exerted. Further, also in the arrester shown in FIG. 5, it is not possible to mount the conductive leaf spring 120 on the outer peripheral surface of the arrester 100 so as to be parallel to the outer surfaces of the line electrodes 104, 104.
The manufacturing process of the conductive leaf spring 120 and the like and the conductive leaf spring 120
It is extremely difficult due to variations in the mounting process. Therefore, as shown in FIG. 6, the conductive leaf spring 120 may be obliquely attached to the surfaces of the line electrodes 104, 104 of the arrester 100. In this case, the conductive leaf spring 1
Since the distance between the wire 20 and the outer surfaces of the line electrodes 104, 104 varies depending on the position, depending on the voltage applied to the lightning arrester 100, the inside of all the small holes 24 of the insulating film 20 located on the surface of the line electrodes 104, 104. Discharge is not started all at once and the function of the vent safe mechanism cannot be fully exerted.

Further, as shown in FIG. 6, the conductive leaf spring 12
0 is not obliquely attached to the surfaces of the line electrodes 104 and 104 of the lightning arrester 100, and the surface of the conductive leaf spring 120 and the surfaces of the line electrodes 104 and 104 are installed substantially in parallel. Even if there is, the insulating film 20 is soft because it is made of a thermoplastic resin such as polyester, and the insulating film 20 is pressed by the conductive leaf spring 120.
Thickness may vary. Such an insulating film 2
A thickness variation of 0 may be one of the causes for causing the discharge starting voltage in each small hole 24 of the insulating film 20 to vary. Therefore, depending on the lightning arrester, the function of the vent-safe mechanism may not be exerted even if an external surge of a predetermined power is applied, or the function of the vent-safe mechanism may be insufficient.

Moreover, since the insulating film used in the conventional arrester is made of thermoplastic resin,
When the conductive leaf spring is connected to the ground electrode by spot welding or the like, the insulation film may be damaged or melted due to heat or sparks of the spot welding, resulting in poor insulation of the insulation film. It is extremely difficult to find such insulation failure from the outside of the arrester. Further, since the polyester film generally used as an insulating film has poor dimensional stability, the variation in the spatial distance between the conductive leaf spring and the line electrode surface becomes large, which may cause the discharge starting voltage to become unstable. Such a polyester film has hygroscopicity, and in regions with high humidity such as the rainy season and in high humidity regions such as the coast, the insulating film absorbs moisture and the discharge start voltage is significantly reduced. You cannot use the arrester used as.

Further, even if the arrester body becomes hot due to the continuous discharge and the insulating film is melted and the conductive leaf spring and the line electrode come into contact with each other, they are contacted by the spring force of the conductive leaf spring. Therefore, the contact resistance is 20-100mΩ
And high. Such a conventional lightning arrester, -40 ℃ ~ +60 ℃
When a temperature cycle test is performed on the arrester in which the conductive leaf spring and the line electrode are in contact, there is an arrester in which the contact between the conductive leaf spring and the line electrode is eliminated, and there is a fail-safe requiring permanent contact. It turned out that the function of the mechanism could not be guaranteed. Therefore, an object of the present invention is to provide a gas arrester in which the respective functions of the fail-safe mechanism and the vent-safe mechanism can be sufficiently exerted.

[0011]

Means for Solving the Problems As a result of repeated studies to achieve the above-mentioned object, the present inventors adopted a film made of a polyimide resin or mica having low hygroscopicity and heat resistance as an insulating film. A lightning arrester in which a thin solder plate is sandwiched between the insulating film and a conductive leaf spring, in which a group of small holes are formed in the portion in contact with the line electrode, has sufficient functions of the fail-safe mechanism and the vent-safe mechanism. The present invention has been achieved by finding out that it can be exerted. That is, the present invention is a gas arrester in which a line electrode and a ground electrode are arranged to face each other with an insulator interposed therebetween,
An insulating film made of a heat-resistant material such as a polyimide resin or mica (mica), in which a group of small holes is provided in a portion located on the surface of the line electrode, is the line electrode and the ground electrode. And an electrically conductive leaf spring electrically connected to the ground electrode and sandwiched between the line electrode, and an insulating film on the line electrode and the electrically conductive leaf spring. Between the line electrode and the insulating film, and the line made of a low melting point metal such as solder or tin that melts at a temperature lower than the decomposition temperature or the softening temperature of the heat-resistant material forming the insulating film. A gas arrester characterized in that a deformable metal thin plate is sandwiched along the outer peripheral surface of the electrode.
In the present invention having such a configuration, in the conductive leaf spring,
The fact that solder plating or tin plating is applied, and the line electrode is subjected to solder plating or tin plating reduces the contact resistance between the conductive leaf spring and the line electrode, which causes the fail-safe mechanism to function. It can be further exerted.

[0012]

In the present invention, when a thin metal plate is sandwiched between the insulating film on the line electrode and the conductive leaf spring, it can be deformed by the conductive leaf spring mounted on the outer peripheral surface of the arrester. Since the metal thin plate and the insulating film are sandwiched along the outer peripheral surface of the arrester, the metal thin plate that is in electrical contact with the conductive leaf spring is attached to the outer peripheral surface of the arrester through the insulating film. It is attached in parallel to the other side. Therefore, even when the conductive leaf spring is obliquely attached to the line electrode surface of the arrester, the metal thin plate and the outer peripheral surface of the arrester are substantially parallel, and the metal thin plate and the line electrode surface are The gap can be kept constant, and the variation in the discharge starting voltage that exerts the function of the vent-safe mechanism can be minimized. On the other hand, when the thin metal plate is sandwiched between the line electrode and the insulating film, the thin metal plate is deformed by the pressing force of the conductive leaf spring and the thickness of the insulating film can be kept constant. It is possible to avoid the variation of the discharge starting voltage due to the variation of the thickness and to exert the function of the vent-safe mechanism.

Moreover, since the insulating film is made of a heat-resistant material having heat resistance such as polyimide resin or mica, even when conducting spot welding of the conductive leaf spring to the earth electrode, insulation is provided by sparks of spot welding. The insulating film is less likely to be damaged or melted, and it is possible to prevent insulation failure of the insulating film that occurs during assembly of the arrester. Also in the fail-safe mechanism, when the thin arrester body is overheated because a thin metal plate made of a low melting point metal such as solder is sandwiched between the small hole group part of the insulating film and the conductive leaf spring. The metal thin plate is melted, the conductive plate spring and the line electrode are connected through the small hole group of the insulating film, and the line electrode and the ground electrode are connected to stop continuous discharge in the arrester. Since the connection between the line electrode and the conductive leaf spring is surely made by the molten low melting point metal, the function of the fail-safe mechanism can be sufficiently exerted.

[0014]

EXAMPLES The present invention will be described in more detail by way of examples. FIG. 1 is an assembly view showing an embodiment of the present invention, in which an outer peripheral surface of an arrester main body 10 containing argon gas in which line electrodes 12, 12 and an earth electrode 14 are arranged with insulators 11, 11 interposed therebetween. An insulating film 20 made of a heat-resistant polyimide resin and having a thickness of 50 μm is sandwiched between the conductive leaf spring 60 made of phosphor bronze or stainless steel. The conductive leaf spring 60, the line electrode 12,
Solder plating is applied to 12 and the ground electrode 14. The insulating film 20 is provided with a group of small holes consisting of a large number of small holes 24 in the portions in contact with the respective surfaces of the line electrodes 12, 12 in the vicinity of both ends thereof, and in the portion in the vicinity of the central portion in contact with the ground electrode 14. The slit 26 is formed. In the small hole group formed in the vicinity of both ends of the insulating film 20, a large number of small holes 24 having a diameter of about 0.2 mm are formed along the line electrode 12.

Further, the conductive leaf spring 60 has a mountain-shaped cross-section with a valley formed in the central portion. The conductive leaf spring 60 has the valley formed in the insulating film 2.
While being pressed against the ground electrode 14 of the arrester body 10 through the slit 26 of 0, it is connected by spot welding or the like and fixed to the outer peripheral surface of the arrester body 10. At this time, even if a spark such as spot welding adheres to the insulating film 20, since the insulating film 20 is a heat-resistant film made of a polyimide resin, melting is less likely to occur and the conductive leaf spring 6
It is possible to prevent insulation failure due to melting of the insulating film 60 due to sparks of the spot welding of 0 and the like. Lightning arrester body 1
The end of the conductive leaf spring 60 fixed to 0 is connected to the arrester 10
The insulating film 20 having a group of small holes provided in a portion in contact with the line electrode 12 is pressed against the outer peripheral surface of the arrester body 10. In this embodiment, between the insulating film 20 provided with the small hole group located on the line electrode 12 and the conductive leaf spring 60, the metal thin plate 4 made of solder and having a thickness of 50 μm.
0 and 40 are sandwiched. Such thin metal plates 40, 40
Can be easily deformed and deformed following the outer peripheral surface of the arrester body 10 together with the insulating film 20 while being in contact with the conductive leaf spring 60.
The line electrodes 12 and 12 are attached substantially parallel to the surface of the line electrodes 12 and 12.

Therefore, as shown in FIG. 2, even if the conductive leaf spring 60 is arranged to be inclined with respect to the outer peripheral surface of the arrester body 10, the thin metal plate 40 which is in contact with the conductive leaf spring 60 is in contact. ,
The distance between 40 and the line electrodes 12, 12 can be kept constant, and even if the argon gas in the arrester body 10 scatters, the function of the vent safe mechanism can be sufficiently exerted. That is, in the present embodiment, the distance between the metal thin plates 40, 40 and the line electrodes 12, 12 can be made constant regardless of the mounting state of the conductive leaf spring 60 on the arrester body 10. Therefore, the insulating film 2 located on the upper surface of the line electrode 12
The discharge can be induced in all the small holes 24 of 0, and the discharge start voltage when the function of the vent-safe mechanism is exerted can be made as constant as possible. As a result, an external surge of a predetermined voltage is applied to the arrester body 10. In this case, the function of the vent safe mechanism can be surely and sufficiently exhibited.

Further, in this embodiment, the insulating film 20 is a heat-resistant film made of polyimide resin which is a heat-resistant resin, but since the thin metal plates 40, 40 on the insulating film 20 are made of solder, When a high voltage is continuously applied to the lightning arrester 10 and a discharge is continuously generated in the lightning arrester main body 10, the thin metal plates 40 and 40 are melted by the heat of the lightning arrester 10, and the generated molten solder is electrically conductive. Line electrode 1 passing through the small hole 24 by the pressing force of the flexible leaf spring 60.
It flows out to the surface of 2 and 12 and electrically connects the conductive leaf spring 60 and the line electrodes 12 and 21. Therefore, the line electrodes 12, 12 and the ground electrode 14 are electrically connected,
The continuous discharge can be stopped to prevent a fire or the like due to overheating of the lightning arrester 10. Moreover, since the line electrodes 12 and 12 and the conductive leaf springs 60 are plated with solder, the line electrodes 12 and 12 and the conductive leaf spring 60 surfaces are well compatible with the molten solder. Contact resistance of 10mΩ
You can: Also, the continuous discharge is stopped and the arrester body 1
Even after 0 was cooled, the line electrodes 12, 12 surface and the conductive leaf spring 60 surface were firmly bonded via solder, and even if a temperature cycle test of −40 to + 60 ° C. was performed, Can still be bonded. In this way, the arrester of this embodiment can sufficiently exert the function of the fail-safe mechanism.

In this embodiment, as a method of laminating the insulating film 20, the metal thin plates 40, 40, and the conductive leaf spring 60 on the outer peripheral surface of the arrester body 10, the insulating film 20 is coated with adhesive on both sides or on one side. Protective film 20 with lightning arrester body 1
After being temporarily fixed to 0, the thin metal plates 40, 40 and the conductive leaf spring 60 are joined. At this time, the small holes 24 are formed after the adhesive layer is formed so that the small holes 24 formed in the insulating film 20 in the portion coated with the adhesive penetrate the adhesive layer. Is preferred. In addition, the metal thin plates 40, 40
The connection between the conductive leaf spring 60 and the conductive leaf spring 60 may be temporarily fixed to the thin metal plates 40, 40 by spot welding or the like.

In the present embodiment shown in FIGS. 1 and 2, since the metal thin plates 40, 40 are placed on the upper surface of the insulating film 20, the temperature of the arrester body 10 is kept at the metal thin plates 40, 4.
If the temperature is not raised above the melting temperature of 0, the metal sheet 4
Since 0 and 40 are not melted, they are suitable as a lightning arrester for high power. However, as a lightning arrester for small electric power, when the temperature of the arrester body 10 reaches the melting temperature of the thin metal plates 40, 40,
It is necessary that the thin metal plates 40, 40 be melted and the function of the fail-safe mechanism be exerted. Therefore, in the arrester for such an application, as shown in FIG.
It is preferable to sandwich 0 between the insulating film 20 and the line electrode 12. According to the arrester shown in FIG. 3, since the heat of the arrester body 10 is directly transferred to the metal thin plates 40, 40, when the temperature of the arrester body 10 reaches the melting temperature of the metal thin plates 40, 40, the metal The thin plates 40, 40 can be melted to exert the function of the fail-safe mechanism.
Moreover, the thin metal plate 4 is pressed by the pressing force of the conductive leaf spring 60.
Since the plate thicknesses of 0 and 40 fluctuate, the fluctuation of the thickness of the insulating film 20 due to the pressing force of the conductive leaf spring 60 is avoided, and the discharge starting voltage in each of the small holes 24 forming the small hole group is set. It can be kept almost constant, and the function of the vent-safe mechanism can be fully exerted.

Further, as shown in FIG. 3, the metal thin plates 40, 4 are
When 0 is sandwiched between the insulating film 20 and the line electrodes 12 and 12, as shown in FIG. 6, when the conductive leaf spring may be obliquely attached to the line electrode surface, As shown in FIG. 4, it is preferable to mount the metal thin plates 42, 42 on the upper surface of the insulating film 20 contacting the metal thin plates 40, 40 contacting the line electrodes 12, 12. The metal thin plates 42, 42 can be easily deformed, and are deformed following the outer peripheral surface of the arrester body 10 together with the insulating film 20 while being in contact with the conductive plate spring 60.
42 is the line electrodes 12 and 1 via the insulating film 20.
It is mounted substantially parallel to the second surface. For this reason, the thin metal plates 42, 42 in contact with the conductive leaf spring 60 and the line electrode 1
The distance between the holes 2 and 12 can be kept constant, and the discharge start voltage in each of the small holes 24 forming the small hole group can be made substantially constant. The metal thin plates 42, 42 may be any metal thin plate that can be easily deformed by the pressure of the conductive leaf spring 60, and like the metal thin plates 40, 40, are made of a low melting point metal such as solder or tin. It may be present or may be a metal such as copper.

In this embodiment described above, as the polyimide resin forming the insulating film 20, a wholly aromatic polyimide resin having a decomposition temperature of 400 ° C. and a heat distortion temperature of 360 ° C. can be preferably used. Any heat resistant resin whose deformation temperature is higher than that of the low melting point metal forming the thin metal plates 40, 40 can be used. Examples of such heat resistant resin include polyamideimide resin and polyetherimide resin. In addition, the insulating film 20
An inorganic material such as mica can be used as the heat-resistant material for forming the. The insulating film 20 made of such an inorganic material is preferable because it does not deteriorate even at an extremely high temperature. Further, as the low melting point metal forming the thin metal plates 40, 40, a low melting point metal that melts below the heat deformation temperature of the insulating film 20 can be used, and a melting point of 200 to 300 ° C. is preferable. As such a low melting point metal, solder or tin can be preferably used. The thickness of the metal thin plates 40, 40 made of these low-melting-point metals should be set so that they can be easily deformed following the outer peripheral surface of the arrester body 10. Can be as parallel as possible. The conductive leaf spring 60 and the copper thin plates 40, 40 may be tin-plated instead of solder in order to reduce the contact resistance between them.

[0022]

According to the present invention, since the insulation failure of the insulating film which occurs at the time of assembling the lightning arrester can be prevented and the functions of the vent-safe mechanism and the fail-safe mechanism of the lightning arrester can be sufficiently exhibited, the lightning arrester is provided. The reliability of can be improved.

[Brief description of drawings]

FIG. 1 is an assembly diagram showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional view of the lightning arrester assembled in FIG.

FIG. 3 is a partial cross-sectional view showing another embodiment.

FIG. 4 is a partial cross-sectional view showing another embodiment.

FIG. 5 is an assembly diagram of a lightning arrester disclosed in Japanese Patent Publication No. 2-3274.

FIG. 6 is a partial cross-sectional view of the lightning arrester assembled in FIG.

FIG. 7: Japanese Patent Laid-Open No. 53-52961 (US Pat. No. 421)
It is an assembly drawing of the arrester described in (No. 2047 specification).

FIG. 8 is a cross-sectional view of the lightning arrester assembled in FIG.

FIG. 9 is a perspective view of a conventional lightning arrester.

FIG. 10 is an assembly diagram of the arrester shown in FIG.

[Explanation of symbols]

 10 Lightning Arrest Body 12 Line Electrode 14 Earth Electrode 20 Insulating Film 24 Small Hole 40 Metal Thin Plate 60 Conductive Leaf Spring

Claims (3)

[Claims] 1. A gas arrester in which a line electrode and a ground electrode are arranged so as to face each other with an insulator interposed, and a small hole group including a large number of small holes in a portion located on the surface of the line electrode. An insulating film made of a heat-resistant material such as polyimide resin or mica, which is provided, is attached between the line electrode and the ground electrode and is electrically connected to the ground electrode, and a conductive leaf spring is provided. While being sandwiched between the line electrode and the insulating film on the line electrode and the conductive leaf spring, or between the line electrode and the insulating film, heat resistance for forming the insulating film. A thin metal plate made of a low melting point metal such as solder or tin that melts at a temperature lower than the decomposition temperature or softening temperature of the conductive material, and is deformable along the outer peripheral surface of the line electrode. Gas-filled lightning arrester that. 2. The gas arrester according to claim 1, wherein the conductive leaf spring is solder-plated or tin-plated. 3. The gas arrester according to claim 1, wherein the line electrode is plated with solder or tin.