KR950011344B1 - Arrester - Google Patents

Abstract

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Description

lightning arrester

1 is a front sectional view showing an arrester according to an embodiment of the present invention.

2 is a partial cutaway front view of a pressure-resistant insulating cylinder applied to an arrester according to an embodiment of the present invention.

3 is a copper cross-sectional view.

4 is an explanatory diagram showing a step of forming a withstand voltage cylinder.

5 and 6 are half sectional views showing a conventional lightning arrester.

7 is a perspective view showing a broken state in a conventional lightning arrester.

8A to 8D are perspective views showing the appearance and the breakdown pressure insulation cylinder after the pressure-proof test of the arrester of the present invention.

* Explanation of symbols for main parts of the drawings

1: Umbrella shaped protrusion 2: Love tube

3: Hallyu element 4: Line side electrode terminal

5: electrode conductive plate 6: electrode

7: pressure gauge 8: seamer bracket

9: sealant 10: grounding electrode terminal

11,29: cap bracket 12: support band

14: pressure-resistant insulating tube 15: electrode

16: heat shrinkable tubing 20: withstand pressure tube

21: ground side electrode 21a: ground side electrode terminal

22: pressure-resistant insulating cylinder fixing pin 23: slit-shaped pressure discharge hole

24: squeezer 241: spring receiving member

242: strip-shaped conductor plate 243: elastic coil spring

25: line side electrode 25a: line side electrode terminal

26: heat shrinkable tubing 27: adhesive

28: insertion hole fixed with pressure-insulated cylinder

A: Core gold F: Reinforcement

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arrester provided with a pressure-proof structure for preventing explosion and scattering when a lightning surge or the like exceeding a rating of an arrester installed in a distribution line or the like arrives.

It is well known that many lightning arresters have been installed and used in power distribution lines in order to protect various equipment from abnormal voltages such as lightning surges in recent years.

As a lightning arrester generally used at present, the gapless lightning arrester which uses zinc oxide (ZnO) as a main component has excellent nonlinear resistance characteristics, and is applied mainly as a current-limiting element.

This requires no series gap, good responsiveness, and sufficient performance of the lightning arrester, such as sufficient duty for multiple lightning strikes, and no deterioration of components due to the non-current flow during operation. It has a number of advantages, such as being capable of miniaturization and light weight, and easy development of a mold type lightning arrester.

As the representative structural example, the lightning arrester shown in the half longitudinal cross-sectional view of FIGS. 5 and 6 is used.

That is, in FIG. 5, the arrester is provided with an umbrella-shaped projection 1 on the outer periphery in multiple stages, and is further provided with an outer shell insulation pipe 2 of a magnetic material (hereinafter, referred to as a single pipe). A plurality of current-limiting elements (3) , The conductive connecting plate (electrode) 5 electrically connected to the line-side electrode terminal 4, and disposed at the line-side open portion (corresponding to the upper end of the drawing) of the open portion. The over-electrode side electrode 6 is arrange | positioned.

In addition, a pressure gauge having an elastic coil spring is disposed directly below the overside electrode 6, and the current-limiting element 3... Is formed by elasticity of the elastic coil spring of the pressure gauge 7. Press to lock it.

On the other hand, the other opening part of the love pipe 2, that is, the ground side opening part (corresponding to the lower end of the same drawing) is provided as if the sealer 8 is sealed through the sealing material 9, and The ground-side electrode terminal 10 is electrically connected to the shimer bracket 8 and attached thereto.

In addition, the line side open portion is wrapped with a cap side bracket which encloses the line side electrode terminal 4 and prevents the intrusion of moisture and dust into the pipe 2.

Reference numeral 12 denotes a support hole for attaching the arrester itself to the power distribution line, and is attached to the lower periphery of the lower pipe 2.

Although the structure of the lightning arrester of FIG. 5 is as described above, the lightning arrester shown in FIG. 6 has a breakdown voltage of the current-limiting element 3 having the above-described nonlinear resistance characteristics formed of an insulating material such as a thermosetting resin, as shown in FIG. A plurality of electrodes are stacked in the insulating cylinder 14, and the electrodes 15 and 15 on the line side or the ground side are disposed at both ends thereof, and these are also heat-shrinkable tubings such as epoxy resins, silicone rubbers, and ethylene acetates. 16) It is a structure coated with.

As described above, the conventional arrester has the above-described structure. However, when installed in the distribution line, the current-limiting element 3 blocks and shows a high resistance value against the normal ground voltage, but if an abnormal voltage such as a lightning surge occurs. When the current-limiting element 3 shows a low resistance value, the abnormal voltage falls to the ground, and when the abnormal voltage of the distribution line is separated, the current-limiting element 3 returns to the fixed value to maintain the normal earth voltage.

This operation protects the peripheral equipment of the distribution line from lightning surges.

Although the arrester fulfills the above functions, when the surge voltage exceeding the rating of the direct lightning strike or the like arrives, the current-limiting element 3 may be broken.

The breaker of the arrester is through breakage or creepage flashover, but in all cases, a large amount of gas is generated by arc heat.

When a large amount of gas is generated in the arrester, the internal pressure increases rapidly.

When such a situation is reached, the following problem arises after the conventional lightning arrester mentioned above.

That is, since the arrester of FIG. 5 has a sealing structure by the magnetic pipe 2 in consideration of the weather resistance of the current-limiting element 3, when the internal pressure rises sharply, the pipe 2 is applied to the internal pressure. Unable to protest, at the end there was a risk of the lightning arrester exploding and flying.

In addition, in the arrester of FIG. 6, as described above, when the surge voltage exceeding the rating of the arrester arrives, the current-limiting element 3 is destroyed, and the internal pressure of the arrester suddenly rises, the withstand pressure insulating cylinder 14 ) Is ruptured by the internal high temperature and high pressure gas, and then the heat shrink tubing 16 is also ruptured and released into the atmosphere.

Therefore, when the above-mentioned arrester is used in the urban area, any possibility of personnel accident increases.

As described above, in the conventional lightning arrester, when the surge voltage resulting from the rating of the arrester arrives, the current-limiting element is destroyed and the internal pressure of the arrester is suddenly increased, the arrester fails to drop. However, the arrester itself has a pressure-proof structure. Due to not doing.

As a lightning arrester having this pressure relief structure, as disclosed in Japanese Patent Laid-Open No. 61-243616 and the like, it is apparent that a rupture plate is disposed between both ends of a love pipe and a cap bracket which is piped thereon. When the current-limiting element is destroyed by the ground, and the pressure inside the pipe is sharply increased, the bursting plate ruptures to form a pressure-pressure path of the high-temperature and high-pressure gas in the pipe, and a lightning arrester having a pressure-proof structure has been proposed to discharge the gas. This arrester requires an attachment bracket for the bursting plate to the pipe, and when the arrester is attached to the power distribution line, they are not only disturbed, but also it is difficult to release the high-pressure internal gas at the moment. Ruptures, easily explodes.

Further, as disclosed in Japanese Patent Laid-Open No. 61-151913, a lightning arrester having a structure in which an internal gas discharge gap is formed between a cap fitting and a pressure-resistant insulating passage and discharges internal gas from this gap, As disclosed in 195811, a pressure-resistant insulator is formed by forming a pressure-resistant insulated tube into a basket shape, and a pressure-protected lightning arrester is proposed, but it is necessary to have a special structure between the cap fitting and the pressure-resistant insulated tube. In addition, since the pressure-resistant insulating cylinder itself is molded into a basket shape, it is necessary to use a special means for the molding, and neither releases the high-pressure gas in the inside of the pipe, and the pipe is ruptured and dropped. It is difficult to prevent the scattering of current-limiting elements.

The present invention has been invented in view of all the above-described aspects, and a scheme for preventing the explosion and scattering of the arrester by quickly discharging the surge voltage even when a lightning arrester or the like exceeding the rating of the arrester. An object of the present invention is to provide an arrester provided with a.

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a lightning arrester that accommodates and fixes a pressure-resistant insulator made of a plurality of current-limiting elements and an elastic insulating material containing a pair of positive electrodes electrically connected to the current-limiting elements in an outer shell insulator made of insulating material. In this configuration, a plurality of slit-type pressure-release holes are provided on the circumferential surface of the pressure-resistant insulating cylinder, and the slit-shaped pressure-resistant holes are in the axial direction of the pressure-resistant insulating cylinder, and the range does not interfere with the external flashover. And a hole in which the slit-shaped pressure-release hole is provided in two or more, preferably three holes, in addition to a hole installed over a range excluding an area requiring strength to hold the current-limiting element. Silver, a reinforcing material such as glass fiber is added to the thermosetting resin, and the reinforcing material may be in an orientation direction within a range of 35 to 55 degrees with respect to the axial direction of the molding. By adopting a molding configuration in the arrester, and the solving means of the problem.

As the structure of the lightning arrester of the present invention, the pressure-proof structure is provided with a slit-type pressure-proof hole on the circumferential surface of the pressure-resistant insulating cylinder, and the range of the installation of the lightning arrester is a range that does not interfere with the transition to the external island along the axial direction and the current-limiting element. The reason why the hole is installed over the range except the area where the required fixed strength is required is that the pressure-resistant insulation cylinder accommodates the current-limiting element. Therefore, the current-limiting element due to the surge in the axial direction and the surge voltage by direct lightning etc. The reason why the area that does not interfere with the external flashover caused by the destruction of the ground is necessary, and the outer circumference of the insulated cylinder is covered with a love pipe having a multi-stage umbrella-shaped protrusion on the outer circumference. If the open area is large, for example, a structure in which circular pressure-release holes are laid out, where the umbrella-shaped protrusion and pressure-pressure hole face each other, If the part is recessed and the pressure-closing hole is closed, the pressure-proofing or appearance is unfavorable, and if the pressure-spreading holes are scattered, there are many cases of rupture outside the pressure-proofing hole. none. For this reason, in this invention, the above-mentioned pressure-release hole was made into the slit shape which opens continuously.

Next, the reason why two or more, preferably two to four, pressure-proof holes are formed in the circumferential surface of the pressure-resistant insulating cylinder is provided in view of the strength of the pressure-resistant insulating cylinder required to resist the pressure of the internal high-pressure gas.

That is, since the strength with respect to the discharge pressure at the time of discharge | release of a high pressure gas is maintained by the area formed between mutual pressure discharge holes, when five or more pressure discharge holes are installed, the area will become small and discharge of high pressure gas will be carried out. If it cannot resist against pressure, and conversely, if it is less than two pressure discharge holes, the area will become large, and the open area of a pressure discharge hole needs to be enlarged, and an influence on strength will arise.

For this reason, in the present invention, two or more, and preferably two to four, pressure-proof holes are formed in the circumferential surface of the pressure-resistant insulation cylinder because of the pressure-proof function and the strength of the pressure-resistant insulation cylinder.

In the pressure-resistant insulating cylinder, a reinforcing material such as glass fiber is added to the thermosetting resin, and the reinforcing material is molded so that the reinforcing material is in an orientation direction within a range of 35 to 55 degrees with respect to the axial direction of the molding. When it is oriented in the direction, the strength in the direction in which the reinforcing material is oriented increases, but it is effective only in that direction, and it is known that the strength in the radial direction of the pressure-resistant insulating cylinder deteriorates.

That is, when the reinforcing material to be blended into the pressure-resistant insulating cylinder is molded in a radially mixed state, it is ruptured and dropped as shown in FIG. 7, and the current-limiting element is scattered. In the experimental result that the barrel ruptured but did not explode, the reinforcing material formulation as described above was used.

EMBODIMENT OF THE INVENTION Hereinafter, the arrester which concerns on the Example of this invention is described in detail based on FIG. 1 thru | or FIG.

1 is a longitudinal cross-sectional view showing an arrester according to an embodiment of the present invention, wherein the ground-side electrode 21 is inserted into one end of a pressure-resistant insulating cylinder 20 made of a thermosetting resin in which reinforcing materials such as glass fibers are recombined. The pin 22 is inserted into the pin hole 28 and fixed.

In this pressure-resistant insulating cylinder 20, a slit pressure-release hole 23 having a shape described later is bored in the axial direction.

Then, the plurality of current-limiting elements (3) and (3) are piled up in the breakdown voltage insulated cylinder (20), and on the other line side opening part (upper end on the upper end of the figure) through the pressure gauge (24). The line side electrode 25 is inserted and the pin 22 is inserted and fixed in the pin hole 28 in the same manner as described above.

The presser 24 has a structure in which a band-shaped conductor plate 242 is fixed to a spring receiving member 241 and an elastic coil spring 243 is provided at a speed thereof. The electrode 25 on the line side and the ground side is provided. The current-limiting element (3) between (21) is pressed in the pressure-resistant insulating cylinder (20) and fixed.

Next, a heat-shrinkable tubing 26 having a multi-stage umbrella-shaped protrusion 26a formed on the outer circumference thereof is prepared, and after applying an adhesive 27 to the inner surface of the tub, the pressure-resistant insulating cylinder 20 And the outer circumference of the base portion of the positive electrodes 25 and 21 on the line and ground sides.

Then, when the lightning arrestor incorporated as described above is put into a heating furnace and heated at a predetermined temperature and time, the heat shrinkable tubing 26 is heat-shrinked and the adhesive 27 is melt-cured and the pressure-resistant insulating cylinder 20 It is fixed close to the outer circumference of).

Reference numerals 25a and 21a denote line caps, terminals of the positive electrodes 25 and 21 on the ground shaft, and caps 26 and 29 that cover the line and ground sides.

The basic structure of the lightning arrester of the present invention is as described above, but the configuration of the pressure-resistant insulating cylinder 20 and the slit-shaped pressure release hole 23 was as follows.

As shown in the front view of FIG. 2 and the cross sectional view of FIG. 3, the slit-like pressure-discharge hole 23 has the pressure-proof hole 23 which has the slit-shaped open area of 6 mm in width and 155 mm in length in the pressure-resistant insulation cylinder 20. As shown in FIG. Holes are drilled along the shaft center at positions of about 60 mm at both ends, and three are provided having a phase of 120 degrees in the circumferential direction as shown in FIG.

As described above, the number of the pressure discharge holes 23 is not limited to the above embodiment, but two or four pressure discharge holes 23 may be provided. However, when the pressure discharge holes 23 are two, the pressure discharge amount of the internal gas is small. As a result, the slit-shaped opening area needs to be 9 mm, which is 1.5 times as wide as the three cases. In the case where four pressure discharge holes 23 are used, the internal pressure of the internal gas increases, but the area between the pressure discharge holes 23 is smaller than that of the three cases, and the groove slightly deteriorates with respect to the pressure of the internal gas. There is this.

This is confirmed from the results of the experiment, and finally, when the three pressure discharge holes 23 are provided with a phase of 120 degrees in the circumferential direction, they are optimal in view of the pressure relief function and the strength of the pressure resistant insulating cylinder 20.

Next, the shaping means of the pressure-resistant insulating cylinder 20 will be described. As shown in the process diagram of FIG. 4, the reinforcing material F formed of a string shape by appropriately attaching a bundle of a plurality of filaments of glass fibers with a binder. Is rotated at a winding angle of 45 degrees with respect to the shaft center of the core A.

Thereafter, the thermosetting resin is impregnated with a reinforcing material (F) wound around a liquid epoxy resin, cooled at room temperature for a predetermined time, and cured.

After hardening, the core A is taken out and the slit-shaped pressure-release hole 23 which has the dimension mentioned above in three places is drilled by machining.

Although the pressure-resistant insulating cylinder 20 is molded as described above, the winding sensitivity of the reinforcing material F is set to a 45 degree winding angle in the above-described embodiment, but the winding angle of 55 degrees to 35 degrees is the same effect.

That is, when the winding of the reinforcing material F is regarded as the circumferential direction, it was found that the tear-off resulted after the discharge was confirmed by the experiment, but in the case of the present embodiment, such a fact was not recognized. .

Thus, when the pressure arrester was tested using the lightning arrester of the present invention as a ball holder, the results of FIGS. 8A to 8D were confirmed.

In other words, FIGS. 8A and 8B are examples of device penetration, while FIG. 8A shows that the heat-shrinkable tubing and the breakdown tube are partially ruptured in the room, but none of them are in an explosive scattering state, and fragments are accommodated within a predetermined range. It is not shorted. In addition, although FIG. 8C and FIG. 8D are examples of a creeping flash surface (small surface), the result similar to the element penetrating example of FIG. 8A and FIG. 8B was recognized also in this case.

According to the arrester of the present invention, the slit-shaped pressure-release hole in the axial direction is drilled in the pressure-resistant insulating cylinder holding the current-limiting element, so that the gas pressure generated therein is directly acted on the heat-shrinkable tubing to form a pressure-resistant path by local destruction. Gas can be released into the atmosphere, and the internal pressure can be lowered to prevent explosion and scattering of the arrester.

Therefore, the stability of this type of arrester is improved, and maintenance and management when applied to the wiring line are easier than in the prior art.

In addition, since the pressure-proof hole drilled in the pressure-resistant insulating cylinder is formed in a slit shape having an optimal pressure-dissipating function, and the pressure-resistant insulating cylinder itself has a special orientation of the reinforcing material, it is easy to form the pressure-resistant path, There is no subsequent rupture drop, and there is no risk of personnel accidents.

In addition, the molding and assembly thereof are also easy.

Claims (2)

A lightning arrester comprising a pressure-resistant insulator made of an elastic insulating material containing a plurality of current-limiting elements and a pair of electrodes electrically connected to the current-limiting element in the outer shell insulator of the insulating material, and fixed in the axial direction of the pressure-resistant insulator. And 2 to 4 slit-shaped pressure-proof holes provided in the range excluding the area where the external flashover is not impaired and the area requiring the strength to accommodate the current-limiting element. The pressure resistant insulating cylinder is formed by adding a reinforcing material such as glass fiber to a thermosetting resin, and the reinforcing material is molded to be in an orientation direction within a range of 35 to 55 degrees with respect to the axial direction of the molded product. Lightning arrester.

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