JP3684773B2 - Lightning arrestor - Google Patents

Description

【００３２】
この測定結果から、従来、価格が安く、重量も軽いことで使用されていたアルミニューム（鋳造）は、レジン含浸テープと接着力が弱く、ステンレス、真鍮、鉄、鉄亜鉛メッキが接着力が強いことが判明した。
【００３３】
次に、電極の構成に関する発明について、図１によって説明する。
【００３４】
図１は、線路側の電極１の詳細な説明図で、同図の（Ａ）は電極１の正面図、（Ｂ）は（Ａ）図の下面図、（Ｃ）は（Ａ）図のＡ−Ａ断面図、（Ｄ）は（Ａ）図のＢ−Ｂ断面図を示す。
【００３５】
本発明の電極は、断面円形で、レジン含浸テープが直接又は間接（防湿テープを介して）に巻き付けられる部分（以下、接合面と略称する）に、平面部ｐを設けるものである。
【００３６】
即ち、１ｂ−ｐは、小径部１ｂに設けた平面部で、図１（Ｂ）の例は小径部１ｂの内端側（ＺｎＯ素子側）に平面部を６面形成した場合、また１ｂ−ｐ′は図１（Ｄ）に示すように、小径部１ｂの溝部分１ｃを挟んだ外側（ねじ部側）に２面設けた例である。
【００３７】
１ｃ−ｐは溝部１ｃに設けた平面部で、図１（Ｃ）に示すように１面設けた場合を示している。
【００３８】
この平面部の形成は、図１の例に限るものではなく、小径部又は溝部のいずれか１箇所又は両方に形成しても良く、また、平面部の面積も、適宜選定して１面又は複数面形成する。要は電極に外部接続導体を接続するときのねじの締付応力（回転力）に対して、電極と防湿テープやレジン含浸テープとの接着強度を考慮して適宜選択して形成する。
【００３９】
以上の説明は線路側の電極１について説明したが、接地側の電極２についても同様に形成する。
【００４０】
このように、電極の外周で、レジン含浸テープとの接合面に平面部を形成すると、円形に比較して回転しにくくなり、接着面の緩みや剥離は抑えられる。
【００４１】
【発明の効果】
以上のように本発明は、電極とレジン含浸テープとの接着力が強固なものとなり、電極に外部接続導体を締め付ける時の応力（回転力）に対して、緩みや剥離等の不具合は生じないので、避雷器としての信頼性が向上する。
【図面の簡単な説明】
【図１】本発明の実施の形態の電極の説明図。
【図２】本発明を適用する避雷器の縦断正面図。
【符号の説明】
１，２…電極
３…ＺｎＯ素子
４…圧接ばね
５…電極板
６…防湿テープ
７，７′…レジン含浸テープ
８…ゴム外被
１ａ…大径部
１ｂ…小径部
１ｃ…溝部
１ｂ−ｐ，１ｂ−ｐ′，１ｃ−ｐ…平面部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a lightning arrester, and more particularly to a lightning arrester having a pressure release function for preventing explosion and scattering when the internal pressure of the lightning arrester increases.
[0002]
[Prior art]
The current lightning arrester basically includes a sintered body mainly composed of zinc oxide as a characteristic element (hereinafter referred to as a ZnO element), an insulating container that hermetically accommodates the ZnO element, a pressure release mechanism, and an electrode. It is composed of And this lightning arrester is installed in power transmission, distribution lines or protective equipment, and when an abnormal voltage such as lightning surge occurs, the ZnO element shows a low resistance value, and the abnormal voltage is released to the ground. When extinguished, the ZnO element returns to a high resistance value and maintains a normal commercial frequency to ground voltage.
[0003]
A lightning arrester protects a protected line or equipment from abnormal voltage by such an action, but when a load other than duty such as direct lightning strike is imposed, the lightning arrester causes internal flashing or penetration damage, An arc is generated inside. This arc energy expands the internal gas and at the same time generates gas from the internal elements such as the ZnO element and raises the internal pressure. In addition, the inside of the insulating container is rapidly heated to cause thermal destruction. If this internal spiral state persists, depending on the arc energy, the internal pressure may increase and explosion explosion may occur. Further, at the time of the latter thermal destruction, if the inside is in a high pressure state, the phenomenon of explosion scattering occurs as in the former.
[0004]
For this reason, in general, a lightning arrester employs a pressure releasing means for releasing the increased internal pressure into the atmosphere and lowering it in order to prevent explosion and scattering.
[0005]
Various means for releasing pressure have been proposed, and the following means are known.
[0006]
(1) A ZnO element is housed in a pressure-resistant insulating cylinder made of a material such as reinforced plastic (FRP) having excellent mechanical strength, heat resistance and pressure resistance, and a thin pressure relief plate is provided on the top and bottom thereof. A means of breaking and releasing internal pressure to the outside.
[0007]
(2) Further, as disclosed in Japanese Patent Laid-Open No. 62-139301, a pressure release hole is provided in a pressure-resistant insulating cylinder that accommodates a ZnO element, and a pressure-resistant insulating cylinder is provided between the pressure-resistant insulating cylinder and the ZnO element. When a high-temperature, high-pressure arc is generated inside the lightning arrester, a coating around the pressure release hole of the pressure-resistant insulation tube and a part of the rubber mold are softened or melted and destroyed by high-pressure gas. A means to forcibly form an arc discharge path that is scattered and communicates with the outside.
[0008]
(3) Further, as disclosed in Japanese Patent Laid-Open No. 2-203501, a heat-resistant insulating cylinder that accommodates the ZnO element is formed of an elastic insulating material, and a plurality of axial slit-shaped openings are formed on the cylindrical surface. A pressure hole is provided, the outer periphery of this heat-resistant insulating cylinder is covered with a heat-shrinkable tube, and the gas pressure generated inside is directly applied to the heat-shrinkable tube via the pressure-release hole, and is released by local destruction. There is known a means for forming a path, releasing gas into the atmosphere to lower the internal pressure, and preventing the arrester from exploding or scattering.
[0009]
[Problems to be solved by the invention]
The means described in (1) above requires that the pressure relief plates be installed above and below the insulating cylinder that accommodates the ZnO element, so that the total length of the lightning arrester becomes long, and the existing lightning arrester, like the lightning arrester. Since it is necessary to achieve insulation coordination with the insulator arc horn, there is a limitation on the external gap length of the power transmission arrester itself, which is not suitable when a shorter overall length is desirable.
[0010]
Further, since the means described in the above (2) and (3) both release pressure by providing a pressure release hole in a pressure-resistant or heat-resistant insulating cylinder that accommodates the ZnO element, there is no need for a pressure release plate, and the entire length of the lightning arrester However, since it has a pressure release hole, it absorbs moisture through the rubber jacket, so that the material of this rubber material has a moisture permeability coefficient. It is necessary to use excellent materials, but it is not suitable for selecting materials with high moisture permeability such as silicon gum.
[0011]
In addition, if there is a space like a pressure release hole, moisture that has absorbed moisture condenses in the space, and there are problems such as affecting the characteristics of the arrester.
[0012]
Therefore, the applicant of the present application has previously proposed a lightning arrester that solves these problems and facilitates automatic production by a machine (Japanese Patent Laid-Open No. 9-74004). However, in the invention of the prior application, when the electrode on the line side and the electrode on the ground side are formed in a cylindrical shape to form a large diameter part or a small diameter part, when the line and the external connection conductor for installation are tightened to this electrode with screws When the screw tightening force is large, there is a possibility that the heat-cured resin-impregnated tape and the electrode are loosened or peeled off, causing the electrode to rotate.
[0013]
The present invention has been made in order to solve such a problem, and is provided with a lightning arrester that enhances the adhesive strength between the electrode and the resin-impregnated tape and does not rotate even if the external connection conductor is firmly tightened to the electrode with a screw. Is intended to provide.
[0014]
[Means for Solving the Problems]
Therefore, in the lightning arrester according to claim 1, electrodes connected to the line side and the ground side are arranged on both end sides of one or a plurality of stacked ZnO elements through pressure contact springs, and both the electrodes and the ZnO elements are arranged. In a lightning arrester constructed by winding a resin-impregnated tape on the outer periphery, heat-curing the resin-impregnated tape, and covering the outer periphery with a rubber sheath, the electrode is formed in a cylindrical shape, and the resin is formed on the outer peripheral surface of the electrode. It is characterized in that a flat portion is provided in at least one place of the joining surface to be joined with the impregnated tape.
[0015]
By forming the electrode in this way, even if the rotation of the electrode is suppressed and the external connection conductor is strongly tightened to the electrode, the adhesion surface between the electrode and the resin-impregnated tape is prevented from being loosened or peeled off.
[0016]
Further, the lightning arrester according to claim 2 arranges electrodes connected to the line side and the ground side on both ends of one or a plurality of stacked ZnO elements via pressure contact springs, In a lightning arrester constructed by winding a resin-impregnated tape on the outer periphery, heat-curing the resin-impregnated tape, and covering the outer periphery with a rubber sheath, the electrode is made of any one of stainless steel, brass, iron, and iron-zinc plating The electrode is formed in a columnar shape, and a flat portion is provided on at least one of the joining surfaces to be joined to the resin-impregnated tape on the outer peripheral surface of the electrode.
[0017]
In this lightning arrester, in addition to the effect of claim 1, it is possible to increase the adhesive force between the electrode and the resin-impregnated tape. Even if the external connection conductor is strongly tightened to the electrode, the adhesive surface between the electrode and the resin-impregnated tape is It is prevented from loosening or peeling.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0019]
FIG. 2 is a longitudinal front view of a lightning arrester according to an embodiment of the present invention, showing an example of a lightning arrester for a relatively low rated voltage such as for power distribution.
[0020]
In FIG. 2, reference numerals 1 and 2 denote line side and ground side electrodes. Since both the electrodes 1 and 2 are formed in substantially the same shape, the electrode 1 will be described below, and the electrode 1 (2) will be described in detail with reference to FIG. However, the large-diameter portion 1a (2a), the small-diameter portion 1b (2b), the groove portion 1c (2c) provided in the circumferential direction on the outer periphery of the small-diameter portion, and the screw portion 1d (2d) to which the external conductor connecting screw is screwed ) And a flat surface portion p, and the small diameter portion 1b is formed to have an outer diameter substantially the same as the outer diameter of the ZnO element 3. The electrodes 1 and 2 also serve as line terminals. The electrode 1 is connected to the line side and the electrode 2 is connected to the ground side.
[0021]
Reference numeral 3 denotes a ZnO element. The ZnO element 3 is made of a sintered body mainly composed of zinc oxide as a characteristic element of the lightning arrester, and is used in a series of one or a plurality according to the rated voltage of the lightning arrester. .
[0022]
4 is a pressure contact spring which is elastically mounted between the upper electrode 1 via one end side of the ZnO element 3 and the electrode plate 5 and presses the entire ZnO element and the ZnO element and the electrodes 1 and 2 together. The pressure contact spring 4 uses a leaf spring, but may be a coil spring.
[0023]
6 is a moisture-proof tape, and is directly wound around the outer peripheral surface of the ZnO element 3 or a part of the outer peripheral surface of the ZnO element 3 and the electrodes 1 and 2 with the press-contact spring 4 interposed therebetween. Prevent moisture from entering.
[0024]
Reference numeral 7 denotes a resin-impregnated tape (prepreg tape) impregnated with FRP resin. The resin-impregnated tape 7 is tightly wound around the outer periphery of the moisture-proof tape 6 and the entire outer periphery of the small diameter portion 1b of the electrodes 1 and 2 without providing a gap. The portions of the electrodes 1 and 2 positioned in the groove portions 1c and 2c are cut in the circumferential direction, the end portions thereof are bent along the grooves, and the resin impregnated tape 7 'is supplementally wound around the groove portions 1c and 2c to fill the groove portions. To do.
[0025]
After the resin-impregnated tapes 7 and 7 'are wound in this manner, the resin-impregnated tapes 7 and 7' are cured by heating. After heat-curing, the outer periphery of the resin-impregnated tape 7, 7 'is covered with a rubber jacket 8 to form a lightning arrester. The rubber jacket 8 is made of EPDM (EP rubber), silicon (rubber) or the like having good weather resistance and having a plurality of shade portions 8 'on the outer periphery.
[0026]
The present invention is characterized by the material and shape of the electrodes 1 and 2 in the lightning arrester shown in FIG.
[0027]
That is, in the above-described invention, the electrode is formed of any material of stainless steel, brass, iron, or iron zinc.
[0028]
The fact that these metals were firmly bonded to the resin-impregnated tape was revealed by the following measurement of the shear adhesive force.
[0029]
The shear adhesive strength was measured by first making a support of 2 mm × 5 mm × 90 mm in thickness using iron, iron (electrogalvanized), stainless steel, aluminum, and copper, and then resin impregnated tape (Emerging Chemical Industry ( Co., Ltd. Product code P-EGT14) made a 5mm x 5mm test piece, sandwiched with a support cleaned with a solvent, fixed with krupp, cured at 150 ° C x 90 minutes, tensile speed 5mm / min Measured with
[0030]
Table 1 shows the measurement results. In Table 1, n represents the number of tests performed under the same conditions on each support.
[0031]
[Table 1]

[0032]
From this measurement result, aluminum (casting), which has been used for its low price and light weight, has weak adhesive strength with resin impregnated tape, and stainless steel, brass, iron, iron galvanized has strong adhesive strength. It has been found.
[0033]
Next, the invention relating to the configuration of the electrodes will be described with reference to FIG.
[0034]
1A and 1B are detailed explanatory views of the electrode 1 on the line side, in which FIG. 1A is a front view of the electrode 1, FIG. 1B is a bottom view of FIG. 1A, and FIG. AA sectional drawing, (D) shows BB sectional drawing of (A) figure.
[0035]
The electrode of the present invention has a circular cross section, and is provided with a flat portion p at a portion (hereinafter abbreviated as a joining surface) where a resin-impregnated tape is wound directly or indirectly (via a moisture-proof tape).
[0036]
That is, 1b-p is a plane portion provided in the small diameter portion 1b. In the example of FIG. 1B, when six plane portions are formed on the inner end side (ZnO element side) of the small diameter portion 1b, 1b- As shown in FIG. 1 (D), p ′ is an example in which two surfaces are provided on the outer side (screw side) sandwiching the groove portion 1c of the small diameter portion 1b.
[0037]
1c-p is a plane part provided in the groove part 1c, and shows a case where one surface is provided as shown in FIG.
[0038]
The formation of the flat portion is not limited to the example of FIG. 1 and may be formed in any one or both of the small diameter portion or the groove portion. Multiple surfaces are formed. In short, it is formed by appropriately selecting the screw tightening stress (rotational force) when connecting the external connection conductor to the electrode in consideration of the adhesive strength between the electrode and the moisture-proof tape or resin-impregnated tape.
[0039]
Although the above description has been made on the electrode 1 on the line side, the electrode 2 on the ground side is formed in the same manner.
[0040]
As described above, when a flat portion is formed on the joint surface with the resin-impregnated tape on the outer periphery of the electrode, it becomes difficult to rotate as compared with a circular shape, and loosening and peeling of the adhesive surface can be suppressed.
[0041]
【The invention's effect】
As described above, the present invention provides a strong adhesive force between the electrode and the resin-impregnated tape, and does not cause problems such as loosening and peeling with respect to stress (rotational force) when the external connection conductor is tightened to the electrode. Therefore, the reliability as a lightning arrester is improved.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of an electrode according to an embodiment of the present invention.
FIG. 2 is a longitudinal front view of a lightning arrester to which the present invention is applied.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 2 ... Electrode 3 ... ZnO element 4 ... Pressure contact spring 5 ... Electrode plate 6 ... Dampproof tape 7, 7 '... Resin impregnation tape 8 ... Rubber outer cover 1a ... Large diameter part 1b ... Small diameter part 1c ... Groove part 1b-p, 1b-p ', 1c-p ... plane part.

Claims (2)

An electrode connected to the line side and the ground side is arranged on both ends of one or a plurality of stacked ZnO elements via pressure contact springs, and a resin impregnated tape is wound around the outer periphery of both the electrodes and the ZnO element, In a lightning arrester constructed by heat-curing the resin-impregnated tape and covering the outer periphery with a rubber jacket,
A lightning arrester characterized in that the electrode is formed in a columnar shape, and a flat surface portion is provided at at least one place of a joining surface that joins the resin-impregnated tape on the outer peripheral surface of the electrode. An electrode connected to the line side and the ground side is arranged on both ends of one or a plurality of stacked ZnO elements via pressure contact springs, and a resin impregnated tape is wound around the outer periphery of both the electrodes and the ZnO element, In a lightning arrester constructed by heat-curing the resin-impregnated tape and covering the outer periphery with a rubber jacket,
The electrode is formed of any material of stainless steel, brass, iron, iron galvanized,
And the lightning arrester characterized by forming the said electrode in a column shape and providing the plane part in at least one place of the joining surface joined to a resin impregnation tape in the outer peripheral surface of this electrode.

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