JPH097806A - Molded lighting arrester - Google Patents

Abstract

PURPOSE: To avoid the scattering of a voltage non-linear resistor due to explosion by a method wherein cavities are provided between the main surface of the voltage non-linear resistor and an electrode as well as forming a thin wall part on the part corresponding to the cavities of a mold resin. CONSTITUTION: On a pair of electrodes 11, 12 fixed and connected to both main surfaces 1a, 1b and having the same outer diameter of a voltage non-linear resistor 1, recessions 11a, 12a are formed on the surfaces corresponding to both main surfaces 1a, 1b as well as terminal parts 11b, 12b are protrusively formed on the opposite sides so that peripheral angle parts may be chamferred. On the other hand, cavities 13, 14 are formed between both main surfaces 1a, 1b of the voltage non-linear resistor 1 and respective recessions 11a, 12a of both electrodes 11, 12 so that the resistor 1 and both electrodes 11, 12 may be molded out of mold resin 15 to be integrated leaving both terminal parts 11b, 12b. Besides, arc trenches 15a, 15a are made to form thin wall parts 15b, 15b on the surfaces of the parts corresponding to both cavities 13, 14. Through these procedures, the safety can be enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a molded arrester for protecting an electric line or a distribution transformer in a distribution line path from a flashover accident due to a lightning surge by using a non-linear resistance.

[0002]

2. Description of the Related Art FIG.
FIG. 8 is a front view showing this type of conventional molded lightning arrester described in Japanese Patent Publication No. JP-A-2003-264, and FIG. In the figure, 1 is a voltage non-linear resistor having a main surface 1a, 1b made of a sintered body containing zinc oxide as a main component at both ends, and 2 and 3 are both main surfaces 1a, 1b of the voltage non-linear resistor 1. The pair of electrodes are fixedly connected to each other, for example, by brazing, and the terminal portions 2a and 3a are provided on the opposite sides, respectively. Reference numeral 4 denotes a molding resin that molds and integrates the voltage non-linear resistor 1 and the electrodes 2 and 3 except for the terminal portions 2a and 3a.

In the molded lightning arrester configured as described above, an overvoltage is generated in the distribution line due to lightning or opening / closing of the line, and when the peak value of this overvoltage exceeds a predetermined value, the voltage nonlinear resistance is exceeded. A large current flows through the body, and the current flowing through the distribution line path is shunted to limit overvoltage, thereby protecting equipment such as an electric line of the distribution line path or a distribution device.

[0004]

Since the conventional molded lightning arrester is constructed as described above, when the current flowing through the voltage non-linear resistor 1 exceeds the discharge withstand voltage, the voltage non-linear resistor 1 is flashed. Since it breaks and an arc is generated inside, the inside of the mold resin 4 instantly becomes high temperature and becomes a high pressure due to rapid thermal expansion. Therefore, even if the mold resin 4 has high mechanical strength, it cannot withstand the impact of the high pressure or the breakdown of the voltage non-linear resistor 1, and the mold resin 4 itself and internal constituent members are completely destroyed by the explosion and scattered. To do.

Even if the discharge withstand voltage is less than the discharge withstand voltage, if the voltage non-linear resistor 1 is deteriorated due to repeated lightning surges, aging or airtightness, it will explode and scatter. There was a safety hazard as it caused harm to people.

The present invention has been made to solve the above problems, and an object thereof is to provide a molded arrester capable of preventing explosion and scattering and improving safety. Is.

[0007]

In the molded arrester according to claim 1 of the present invention, electrodes are connected to both main surfaces of the voltage non-linear resistor, and the voltage non-linear resistor and the electrode are terminals of this electrode. A molded lightning arrester covered with a mold resin while leaving a portion is provided with a gap between the main surface of the voltage non-linear resistor and the electrode, and a thin portion is formed in a portion corresponding to the gap of the mold resin.

The molded arrester according to a second aspect of the present invention is the molded lightning arrester according to the first aspect, wherein a cylindrical buffer member is embedded inside the mold resin so as to surround the outer periphery of the voltage non-linear resistor.

Further, a mold arrester according to a third aspect of the present invention is the mold arrester according to the first aspect, in which an annular buffer member is wound along the outer peripheral surface of the mold resin.

Further, a mold arrester according to a fourth aspect of the present invention is the molded lightning arrester according to the first aspect, wherein the cylindrical cushioning member is arranged so as to surround the outer peripheral portion of the mold resin with a predetermined interval.

According to a fifth aspect of the present invention, in the molded lightning arrester according to the fourth aspect, the buffer member is formed in a bell shape in which one is fixed to the terminal portion of the electrode and the other is opened.

Further, a mold arrester according to a sixth aspect of the present invention is the molded lightning arrester according to any one of the second to fifth aspects, wherein the buffer member is formed of butadiene rubber.

According to a seventh aspect of the present invention, in the molded lightning arrester according to the first aspect, both electrodes are formed to have the same outer diameter as the voltage non-linear resistor, and the outer peripheral corners on opposite sides are rounded. It has been given.

According to an eighth aspect of the present invention, there is provided the molded lightning arrester according to the first aspect, in which a conductive flexible member is urged between the main surface of the voltage nonlinear resistor and the electrode. It has been inserted.

[0015]

In the mold arrester according to the first aspect of the present invention, the stress due to the internal arc is concentrated by the air gap, and the stress is diffused by breaking the thin portion of the mold resin.

Further, in the molded lightning arrester according to the second aspect of the present invention, scattering of the molded resin destroyed by the tubular buffer member is prevented.

Further, in the mold arrester according to the third aspect of the present invention, scattering of the mold resin destroyed by the annular buffer member is prevented.

Further, in the molded lightning arrester according to the fourth aspect of the present invention, scattering of the molded resin destroyed by the tubular buffer member is prevented.

Further, in the mold arrester according to the fifth aspect of the present invention, scattering of the mold resin destroyed by the bell-shaped buffer member is prevented.

Further, in the molded lightning arrester according to the sixth aspect of the present invention, the wear resistance and the low temperature characteristics are improved by forming the cushioning member with butadiene rubber.

Further, in the molded surge arrester according to claim 7 of the present invention, both electrodes are formed to have the same outer diameter as that of the voltage non-linear resistor, and the outer peripheral corners on the opposite sides are rounded so that the electrode outer periphery is rounded. Alleviates the concentration of stress on the part.

Further, in the molded arrester according to the eighth aspect of the present invention, a flexible member having conductivity is used to secure a current path between the voltage non-linear resistor and the electrode.

[0023]

【Example】

Embodiment 1 FIG. An embodiment of the present invention will be described below with reference to the drawings. 1 is a front view showing a molded lightning arrester according to a first embodiment of the present invention, and FIG. 2 is a sectional view showing a section taken along line II-II in FIG. In the figure, the voltage nonlinear resistor 1 is the same as the conventional one. Reference numerals 11 and 12 denote a pair of electrodes having the same outer diameter as that of the voltage non-linear resistor 1 and fixedly connected to both principal surfaces 1a and 1b by brazing or the like. Recesses 11a and 12a are formed on the corresponding surfaces, and terminal portions 11b and 12b are formed so as to protrude on opposite sides, and the outer peripheral corners are rounded as shown by A in the figure, that is, rounded. It has been processed.

Reference numerals 13 and 14 denote both main surfaces 1a and 1b of the voltage non-linear resistor 1, and recesses 11a and 12 of the electrodes 11 and 12, respectively.
a is a space formed with a, and 15 is a voltage nonlinear resistor 1
And both electrodes 11, 12 are molded with a molding resin that molds and integrates both terminals 11b, 12b, and both gaps 1
Arc-shaped grooves 15a, 15 on the surface of the portion corresponding to 3, 14
By processing a, thin portions 15b, 15
b is formed. Reference numeral 16 is a cylindrical cushioning member embedded in the mold resin 15 so as to surround the outer periphery of the voltage nonlinear resistor 1, and 17 is a Z-shaped spring made of a conductive member disposed in each of the voids 13 and 14. Then, the two principal surfaces 1a and 1b of the voltage non-linear resistor 1 and the recesses 11a and 12a of the electrodes 11 and 12, respectively.
It is interposed in a biased state between and, and electrically connects the voltage non-linear resistor 1 and both electrodes 11 and 12.

In the molded lightning arrester configured as described above, an overvoltage is generated in the distribution line due to lightning or opening / closing of the distribution line, and the peak value of this overvoltage has a predetermined value. When it exceeds, a large current flows through the voltage non-linear resistor, and the current flowing through the distribution line path is shunted to limit the overvoltage, thereby protecting the equipment such as the electric line of the distribution line path or the distribution equipment.

When the flowing current exceeds the discharge withstand amount, the voltage non-linear resistor 1 undergoes flashover breakdown, and the voltage non-linear resistor 1
Is broken and an arc is generated inside, but both electrodes 11, 12
Since the voids 13 and 14 are formed by the recesses 11a and 12a, the pressure increase in the voids 13 and 14 having a high diffusion rate is the fastest, and the voltage nonlinear resistor 1 and the electrodes 11 and 1 are
The vicinity of the interface with 2 will be destroyed first, but since thin portions 15b, 15b having low strength are formed in that portion respectively, this portion is destroyed first to diffuse the internal stress, Prevents stress from spreading to other parts.

Further, the broken pieces of the molded resin 15 which have been broken are prevented from scattering by the cylindrical buffer member 16 embedded inside. In addition, since the outer peripheral corners of both electrodes 11 and 12 are rounded, stress concentration can be relieved and fracture strength can be improved.
Furthermore, the Z-shaped spring 17 made of a conductive member is urged between the main surfaces 1a and 1b of the voltage non-linear resistor 1 and the recesses 11a and 12a of the electrodes 11 and 12, respectively. It is possible to secure the contact state and increase the energization flow path without the need for any other fixing means.

Embodiment 2 FIG. 3 is a front view showing a molded arrester in Embodiment 2 of the present invention, and FIG. 4 is a sectional view showing a section taken along line IV-IV in FIG. In the figure, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 18 denotes an annular cushioning member wound around the outer peripheral surface of the mold resin 15.

In the second embodiment configured as described above, instead of the tubular cushioning member 16 in the first embodiment, an annular cushioning member 18 is wound around the outer peripheral surface of the mold resin 15. Therefore, as in the case of the above-described first embodiment, even if the mold resin 15 is destroyed by the flashing breakdown of the voltage nonlinear resistor 1 due to the current flowing through the voltage nonlinear resistor 1 exceeding the discharge withstand capability. It goes without saying that the annular cushioning member 18 prevents the broken pieces from scattering, and it is possible to improve safety.

Example 3. 5 is a front view showing a molded lightning arrester according to a third embodiment of the present invention, and FIG. 6 is a sectional view showing a section taken along line VI-VI in FIG. In the figure, the same parts as those in the first and second embodiments are designated by the same reference numerals and the description thereof will be omitted. Reference numeral 19 denotes a buffer member arranged so as to surround the outer peripheral portion of the mold resin 15 with a predetermined gap, and a rod-shaped metal terminal extension portion 19a fixed and connected to the tip of the terminal portion 11b of the electrode 11. A cover portion 19b, one of which is fixed to the terminal extension 19a and the other of which is open, is formed in a bell shape.

In the third embodiment configured as described above, the bell-shaped cushioning member 19 is used as the terminal portion 1 of the one electrode 11.
Since the mold resin 15 is arranged so as to surround the outer periphery of the mold resin 15 with a predetermined gap from the 1b side, the current flowing through the voltage nonlinear resistor 1 is the same as in the first and second embodiments. Even if the molding resin 15 is destroyed due to flashover breakdown of the voltage non-linear resistor 1 beyond the discharge withstand capability, the cover portion 19b of the buffer member 19 can further sufficiently prevent the fractured pieces from scattering, resulting in higher safety. Can be improved.

Example 4. Although no description has been made of the material of the cushioning members 16, 18 and 19 in each of the first to third embodiments, if the cushioning member is made of, for example, butadiene rubber, it has sufficient impact resilience and Since it has excellent wear resistance and low-temperature characteristics, it becomes possible to obtain a molded arrester suitable for outdoor installation.

Example 5. Further, in each of the above-described first to third embodiments, the case where each of the buffer portions 16, 18, and 19 is applied independently has been described, but it is possible to further improve the safety by appropriately combining and using them. Needless to say.

[0034]

As described above, according to claim 1 of the present invention, the electrodes are respectively connected to both main surfaces of the voltage non-linear resistor, and the voltage non-linear resistor and the electrode are the terminal portions of the electrodes. In the molded lightning arrester covered with the mold resin, the gap between the principal surface of the voltage non-linear resistor and the electrode was formed, and the thin portion was formed in the portion corresponding to the gap of the mold resin. It is possible to provide a molded arrester capable of preventing the resistor from scattering due to explosion and improving safety.

According to a second aspect of the present invention, in the first aspect, since the cylindrical buffer member is embedded inside the mold resin so as to surround the outer periphery of the voltage nonlinear resistor, the voltage nonlinear resistor is formed. It is possible to provide a molded lightning arrester capable of preventing scattering due to explosion of the body as well as preventing scattering of the molding resin and further improving safety.

According to the third aspect of the present invention, in the first aspect, since the annular cushioning member is wound along the outer peripheral surface of the mold resin, scattering of the voltage nonlinear resistor due to explosion is prevented. Needless to say, it is possible to provide a molded arrester capable of preventing scattering of the molding resin and further improving safety.

According to a fourth aspect of the present invention, in the first aspect, since the cylindrical cushioning member is arranged so as to surround the outer peripheral portion of the mold resin with a predetermined gap, the voltage non-linear resistance. It is possible to provide a molded lightning arrester capable of preventing scattering due to explosion of the body as well as preventing scattering of the molding resin and further improving safety.

According to a fifth aspect of the present invention, in the fourth aspect, since the buffer member is formed in a bell shape in which one is fixed to the terminal portion of the electrode and the other is opened, the voltage non-linear resistor explodes. It is possible to provide a molded lightning arrester capable of preventing the scattering of the mold resin and further improving the safety by preventing the scattering of the molding resin.

According to claim 6 of the present invention, in any one of claims 2 to 5, since the cushioning member is formed of butadiene rubber, the mold is suitable not only for improving safety but also for outdoor installation. A lightning arrester can be provided.

According to a seventh aspect of the present invention, in the first aspect, both electrodes are formed in the same outer shape as the voltage non-linear resistor, and the outer peripheral corners on opposite sides are rounded. Therefore, it is possible to provide a molded arrester capable of alleviating the concentration of stress on the outer peripheral portion of the electrode and improving the breaking strength.

According to claim 8 of the present invention, in claim 1, the conductive flexible member is interposed between the main surface of the voltage non-linear resistor and the electrode. As a result, the contact state is secured without the need for a separate fixing means,
Further, it is possible to provide a molded arrester capable of increasing the number of energization flow paths.

[Brief description of drawings]

FIG. 1 is a front view showing a molded lightning arrester according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a section taken along line II-II in FIG.

FIG. 3 is a front view showing a molded lightning arrester according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a front view showing a molded lightning arrester according to a third embodiment of the present invention.

6 is a cross-sectional view showing a cross section taken along line VI-VI in FIG.

FIG. 7 is a front view showing a conventional molded arrester.

8 is a sectional view showing a section taken along line VIII-VIII in FIG. 7. FIG.

[Explanation of symbols]

1 voltage non-linear resistor, 1a, 1b main surface, 11, 12
Electrodes, 11a, 12a Recesses, 11b, 12b Terminals, 13, 14 Voids, 15 Mold resin, 15a
Groove, 15b thin-walled portion, 16, 18, 19 cushioning member, 1
7 Spring (flexible member).

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takuro Nagasato 6-16-1 Tsukaguchihonmachi, Amagasaki City Mitsubishi Electric Engineering Co., Ltd. Itami Works

Claims (8)

[Claims] 1. A molded lightning arrester in which electrodes are respectively connected to both main surfaces of a voltage non-linear resistor, and the voltage non-linear resistor and the electrodes are covered with a mold resin leaving the terminal portions of the electrodes. A molded lightning arrester characterized in that a void is provided between the main surface of the voltage non-linear resistor and the electrode, and a thin portion is formed in a portion of the molding resin corresponding to the void. 2. The molded lightning arrester according to claim 1, wherein a cylindrical buffer member is embedded in the mold resin so as to surround the outer periphery of the voltage nonlinear resistor. 3. The molded lightning arrester according to claim 1, wherein an annular cushioning member is wound along the outer peripheral surface of the mold resin. 4. The molded lightning arrester according to claim 1, wherein a cylindrical cushioning member is provided on an outer peripheral portion of the mold resin so as to surround the mold resin at a predetermined interval. 5. The molded lightning arrester according to claim 4, wherein one of the buffer members is fixed to the terminal portion of the electrode and is formed in a bell shape that opens to the other. 6. The molded arrester according to claim 2, wherein the buffer member is made of butadiene rubber. 7. The molded surge arrester according to claim 1, wherein both electrodes have the same outer diameter as the voltage non-linear resistor and are rounded at the outer peripheral corners on the opposite sides. 8. A flexible member having electrical conductivity is urged in the void and is interposed between the main surface of the voltage non-linear resistor and the electrode. 1. The molded arrester according to 1.