JP2007281353A - Arrester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain enhancement in workability during assembly for an arrester in which the outer periphery of laminated zinc oxide elements is coated with a jacket mainly made of a rubber polymer material. <P>SOLUTION: In the arrester, a pair of electrodes 4, 5 are disposed at both sides of a series body 3 constituted of a zinc oxide element block 1 and a presser spring 2 and both the electrodes 4, 5 are fastened by an insulating rod 6 to constitute a zinc oxide element module 8. In such an arrester, the fastening part of both the electrodes 4, 5 and the insulating rod 6 is configured to insert one end side of the insulating rod 6 into a fitting hole 4b of one electrode 4 and fasten it from both sides of the fitting hole 4b using nuts 7a, 7b, and to insert the other end side of the insulating rod 6 into a fitting hole 5b of the other electrode 5, fasten it from an anti-series body side using a nut 7c and fix it in flange parts 4a, 5a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lightning arrester that is connected to an electric power system and protects electrical equipment from abnormal voltages such as switching surges and lightning surges generated in a circuit, and in particular, a silicone rubber or a polymer on an outer peripheral part in which a plurality of zinc oxide elements are laminated. The present invention relates to a lightning arrester with an outer cover formed of an insulating material such as the above.

The basic structure inside the lightning arrester with an insulating material such as silicone rubber or polymer is fastened to the electrodes placed on both ends of the laminate with insulators such as FRP placed around the laminate of zinc oxide elements. Configured. Since the insulating material of the jacket does not have rigidity, an insulator such as FRP is used to provide mechanical strength as a lightning arrester.
As a conventional technology of such a lightning arrester, for example, an upper metal fitting and a lower metal fitting are arranged above and below a laminated zinc oxide element, and the upper and lower metal fittings are fixed with an FRP rod which is a strength member, and the surroundings are made of rubber. What is molded with a jacket member mainly composed of a high molecular weight polymer material is known. The upper metal fitting, the lower metal fitting, and the FRP bar are fixed by passing the FRP bar through both metal fittings and tightening nuts from both sides (for example, see Patent Document 1).

  Further, as another example of fixing the upper electrode portion and the lower electrode portion disposed at both ends of the zinc oxide element block and the insulating rod, a pressing plate having a conical hole extending on the end portion side is used as both electrodes. A technique for fixing the upper and lower electrodes and the insulating rod by inserting the insulating rods into the conical holes of the upper and lower pressing plates and fitting the insulating rods to the pressing plates by fitting the conical wedges from both ends of the insulating rod. Is disclosed (for example, see Patent Document 2).

JP-A-6-310307 (second page, FIG. 1) JP 2002-175905 A (2nd page, FIG. 1)

  In the conventional lightning arrester as shown in Patent Document 1, a through hole is provided in the upper metal fitting and the lower metal fitting, which are electrodes arranged above and below the laminated zinc oxide element, to pass the FRP rod, and the FRP rod passes through the through hole. And fastened with nuts from both sides. Therefore, in the lightning arrester assembly process, first pass the FRP rod through the through hole of the lower metal fitting and screw the nut from the end side, but the through hole is larger than the diameter of the FRP rod. It is not fixed and slips off. Also, when stacking zinc oxide elements on the lower metal fitting and passing the FRP rod through the through hole of the upper metal fitting, it is necessary to lift all the FRP rods and pass them through the through hole of the upper metal fitting at the same time. There was a problem of being bad.

  In the lightning arrester shown in Patent Document 2, since the electrode portion and the insulating rod are fixed with the conical wedge, the insulating rod is prevented from slipping during the assembly, and the assembling workability is improved. For example, when a load is applied to the insulation rod due to electromagnetic force generated during a lightning arrester accident, the fitting portion of the insulation rod becomes a weak point and the fastening may be loosened. It was.

  The present invention has been made to solve the above-described problems, and it is possible to improve the workability at the time of assembly and to obtain a lightning arrester having sufficient strength at the fastening portion between the electrode and the insulating rod. Objective.

  A lightning arrester according to the present invention includes a zinc oxide element block in which a plurality of zinc oxide elements are stacked, a pressing spring disposed on one end surface of the zinc oxide element block, and both sides of a series body of the zinc oxide element block and the pressing spring. And a pair of electrodes having flanges on the side facing the series body, and a plurality of insulating rods that fasten both electrodes by attaching both ends to the mounting holes formed in the flanges. In the lightning arrester in which the outer periphery of the zinc oxide element module is coated with a rubber-based polymer material as a main component by a mold, the fastening portion between both electrodes and the insulating rod is at both ends of the insulating rod. Inserted into the mounting hole of one of the electrodes and tightened with a nut from both sides of the mounting hole, and the other end of the insulating rod was inserted into the mounting hole of the other electrode and Attached because those are fixed to each flange portion.

  According to the lightning arrester of the present invention, the insulating rod for tightening the zinc oxide element block and the one electrode are formed by tightening the insulating rod penetrating the mounting hole from both sides of the mounting hole to the buttocks with the nut and fastening with the other electrode. Since the insulation rod passed through the mounting hole was fixed to the flange with a nut from the anti-serial body side of the mounting hole, the insulation rod slipped down when the zinc oxide element block was assembled between both electrodes. Since it does not wobble, and there is no co-rotation when the nut is tightened, workability during assembly is improved. Further, since the nut is fastened, a sufficient strength can be secured at the fastening portion between the electrode and the insulating rod.

Embodiment 1 FIG.
1 is a cross-sectional view of a lightning arrester according to Embodiment 1 of the present invention. (A) of a figure shows side surface sectional drawing, (b) shows the plane sectional drawing of the principal part seen from II of (a). As shown in the figure, a zinc oxide element block 1 is formed by stacking a plurality of columnar zinc oxide elements 1a at the center. A pressing spring 2 that applies a pressing force to the zinc oxide element block 1 is disposed on one end side (upper side in the drawing) of the zinc oxide element block 1. The pressing spring 2 is illustrated as a coil spring in the figure, but may be a disc spring or the like.
A series body 3 is constituted by the zinc oxide element block 1 and the pressing spring 2. A lower electrode 4 and an upper electrode 5 are arranged on both sides of the series body 3, and flanges 4 a and 5 a are formed on the opposite sides of the electrodes 4 and 5, respectively. A plurality of mounting holes 4b and 5b (four in each figure) for mounting the insulating rod 6 are provided on the outer peripheral portions of the flange portions 4a and 5a.

  The insulating rod 6 is formed with threaded portions at both ends, and is arranged at substantially equal intervals around the zinc oxide element block 1. The fastening portion between the insulating rod 6 and the lower electrode 4 and the upper electrode 5 has one end of the insulating rod 6 inserted into the mounting hole 4b of the lower electrode 4 and is tightened with nuts 7a and 7b from both sides of the mounting hole 4b. The other end is inserted into the mounting hole 5b of the upper electrode 5, and is fastened with a nut 7c from the opposite side (anti-series body side) of the series body 3 to be fixed to the flanges 4a and 5a. In this state, the zinc oxide element block 1 is pressed by the pressing force of the pressing spring 2, and is firmly fixed and integrated between the electrodes 4 and 5, and the zinc oxide element module 8 is constituted as a whole. Yes.

An outer cover 9 made of an insulating material (eg, silicone rubber or polymer having weather resistance) mainly composed of a rubber-based polymer material is integrally formed by a mold so as to cover the periphery of the zinc oxide element module 8. The lightning arrester is configured.
If the arrangement relationship between the zinc oxide element block 1 and the insulating rod 6 is shown in a plan sectional view, it becomes as shown in FIG. 1B, and the insulating rod 6 is formed with a slight gap in the radial direction of the zinc oxide element block 1. Has been placed. This is a gap for preventing the nut 7a existing on the side of the lower electrode 4 in contact with the zinc oxide element block 1 from interfering with the zinc oxide element 1a and enabling the nut 7a to be fastened.

In the lightning arrester configured as described above, an assembling operation in which the zinc oxide element 1a is laminated and assembled between the lower electrode 4 and the upper electrode 5 will be described.
First, a nut 7a (a washer is combined with a nut, but the washer is omitted in the following description) is inserted into one end of the insulating rod 6, and screwed to a predetermined position. Next, the end on the side into which the nut 7a is screwed is inserted into the mounting hole 4b formed in the flange 4a of the lower electrode 4 until the nut 7a comes into contact, and another nut 7b is screwed in from the end. Then, one of the nuts on both sides of the mounting hole 4b is fixed with a tool, and the other is fastened with a predetermined torque to be fixed to the flange 4a. All the insulating rods 6 are attached to the flange 4a in the same manner. When completed, the four insulating rods 6 are erected vertically on the flange portion 4 a of the lower electrode 4.
The number of insulating rods is not limited to four, and may be three or six.

Next, the zinc oxide element block 1 is formed by stacking the zinc oxide elements 1 a in the center portion surrounded by the four insulating rods 6 erected. The pressing spring 2 is disposed on the zinc oxide element block 1, and from above, the mounting hole 5b of the upper electrode 5 is aligned with the upper end portion of the insulating rod 6, and the nut 7c is inserted from the anti-series body side of the mounting hole 5b. Screw and tighten the flange 5a. At this time, since a strong reaction force of the pressing spring 2 is applied, it is desirable to use a jig that presses the pressing spring 2 and keeps the electrodes 4 and 5 at a predetermined distance.
By these operations, the series body 3 of the zinc oxide element block 1 and the pressing spring 2 is sandwiched between the electrodes 4 and 5, and is firmly fixed by the insulating rod 6 and the nut 7 (7a to 7c) to be integrated. In addition, the zinc oxide element module 8 is assembled.
Thereafter, the above-described jacket 9 is formed on the outer periphery of the zinc oxide element module 8 by molding to complete the lightning arrester.

  As described above, the invention of the present embodiment is characterized in that when one end of the insulating rod 6 is attached to the lower electrode 4, it is fixed by being sandwiched from both sides of the flange portion 4a by two nuts. According to such a configuration, the insulating rod 6 does not slide down or sway from side to side during assembly work, so that the stacking work of the zinc oxide elements 1a can be facilitated, and the upper electrode 5 is also easily made. It can be inserted into the insulating rod 6. In addition, since the lower side is fixed using two nuts 7a and 7b, when the upper side nut 7c is tightened, the lower side fastening portion does not rotate together. There is no need for fixing work and the tightening work is simplified.

  In the figure, the lower electrode 4 and the insulating rod 6 are fixed with two nuts, and the upper electrode 5 and the insulating rod 6 are fixed with one nut. The electrode 5 side may be fixed with two nuts, and the lower electrode 4 side may be fixed with one nut.

  As described above, according to the invention of the present embodiment, the fastening portion between the electrode and the insulating rod arranged at both ends of the zinc oxide element block is inserted into one electrode mounting hole at one end side of the insulating rod. Tighten with nuts from both sides of the mounting hole, and insert the other end of the insulating rod into the mounting hole of the other electrode and tighten it with the nut from the anti-series body side, and fix it to each flange. The work of assembling can be improved because the insulating rod does not slide down or sway during the assembly work, and no co-rotation occurs when the nut is tightened. In addition, since a sufficient strength can be secured at the fastening portion between the electrode and the insulating rod because of the fastening with the nut, a lightning arrester having sufficient strength against the electromagnetic force generated when a short-circuit current flows is provided. Can do.

Embodiment 2. FIG.
2A and 2B are cross-sectional views of a lightning arrester according to Embodiment 2 of the present invention, in which FIG. 2A is a side cross-sectional view and FIG. Since the basic structure composed of the zinc oxide element block, the pressing spring, the upper and lower electrodes, the insulating rod, the nut, and the jacket is the same as that of FIG. 1 of the embodiment, the same parts are denoted by the same reference numerals and the description is omitted. The explanation will focus on

The part different from FIG. 1 is the structure of the electrode on the side fastened to the insulating rod by two nuts. In the case of FIG. 2, the lower electrode corresponds to this. The lower electrode 10 of the present embodiment is basically similar to the lower electrode 4 described in FIG. 1 of the first embodiment, and is the side facing the series body 3 of the zinc oxide element block 1 and the pressing spring 2. The flange portion 10a is provided with a mounting hole 10b. The difference is that an element receiving portion 10c having an outer diameter smaller than the outer diameter of the zinc oxide element 1a is further provided on the surface of the flange portion 10a facing the series body 3.
In addition, although the element receiving part 10c showed what was integrally formed with the lower electrode 10 in the figure, it is good also as another member. Further, contrary to the figure, the upper electrode 5 side may be fastened with two nuts, and an element receiving portion may be provided on the surface of the flange portion 5a. In short, it is only necessary that the element receiving portion be provided on the electrode on the side where one end of the insulating rod is fastened with two nuts.

  By adopting such a structure, a space having a difference in outer diameter between the zinc oxide element block 1 and the element receiving portion 10c is created, so that interference between the nut 7a and the outer periphery of the zinc oxide element block 1 can be avoided, and insulation is achieved. The rod 6 can be disposed close to the outer peripheral surface side of the zinc oxide element block 1. If the difference between the outer diameter of the zinc oxide element 1a and the outer diameter of the element receiving portion 10c is larger than the difference between the outer diameter of the nut 7a and the outer diameter of the insulating rod 6, the insulating rod 6 is brought into close contact with the zinc oxide element block 1 Until you are close. That is, it can arrange | position in a state as shown in FIG.2 (b).

FIG. 3 shows another example of the lightning arrester according to the second embodiment of the present invention. (A) is side surface sectional drawing, (b) is a plane sectional view of the principal part seen from III-III of (a).
The components of the lightning arrester are the same as those in FIG. 1 of the first embodiment. The difference from FIG. 1 is the insertion position of the pressing spring 2 and the arrangement of the insulating rod 6 associated therewith.
As shown in FIG. 3, the pressing spring 2 is interposed between the electrode on the side fastened using two nuts 7a and 7b, ie, the lower electrode 4 and the zinc oxide element block 1 in this figure. Yes. And the outer diameter of the press spring 2 is made smaller than the outer diameter of the zinc oxide element 1a.

  With such a configuration, it is possible to place the insulating rod 6 close to the outer peripheral surface side of the zinc oxide element block 1 as in the case of FIG. The planar cross section of the zinc oxide element block 1 and the insulating rod 6 is as shown in FIG. 3B. By devising the outer diameter of the pressing spring 2, it can be brought close to close contact.

  As described above, according to the invention of the present embodiment, in the lightning arrester configured as in the first embodiment, the electrode on the side where one end of the insulating rod is fastened by two nuts is opposed to the series body. Since the element receiving portion having the outer diameter portion smaller than the outer diameter of the zinc oxide element is provided on the surface to be performed, the insulating rod can be disposed close to the zinc oxide element block in addition to the same effect as in the first embodiment. Compared to the first embodiment, the outer diameter of the jacket can be reduced, and the effect that the lightning arrester can be reduced in size and weight can be obtained.

  Also, the pressing spring is arranged between the electrode on the side where one end of the insulating rod is fastened by two nuts and the zinc oxide element block, and its outer diameter is made smaller than the outer diameter of the zinc oxide element. The same effect as described above can be obtained with a simple electrode structure.

It is sectional drawing which shows the lightning arrester in Embodiment 1 of this invention. It is sectional drawing which shows the lightning arrester in Embodiment 2 of this invention. It is sectional drawing which shows the other example of the lightning arrester in Embodiment 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Zinc oxide element block 1a Zinc oxide element 2 Pressing spring 3 Inline body 4 Lower electrode 4a collar part 4b Mounting hole 5 Upper electrode 5a collar part 5b Mounting hole 6 Insulating rod 7a, 7b, 7c Nut 8 Zinc oxide element module 9 Jacket 10 lower electrode 10a collar portion 10b mounting hole 10c element receiving portion.

Claims (3)

A zinc oxide element block in which a plurality of zinc oxide elements are laminated, a pressure spring disposed on one end surface of the zinc oxide element block, and disposed on both sides of a series body of the zinc oxide element block and the pressure spring. A zinc oxide element module comprises a pair of electrodes having flanges on the side facing the series body, and a plurality of insulating rods that attach both ends to the mounting holes formed in the flanges and fasten the electrodes. In a lightning arrester constructed and coated with a mold with a jacket mainly composed of a rubber-based polymer material around the zinc oxide element module,
The fastening portion between the two electrodes and the insulating rod is such that one end of the insulating rod is inserted into the mounting hole of one of the electrodes and is tightened with nuts from both sides of the mounting hole. A lightning arrester characterized in that the other end side is inserted into a mounting hole of the other electrode and is fastened with a nut from the anti-series body side and fixed to each of the flanges.   2. The lightning arrester according to claim 1, wherein an element having an outer diameter portion smaller than an outer diameter of the zinc oxide element is provided on a surface of the flange portion of the one electrode that is tightened with a nut from both sides of the mounting hole. A lightning arrester characterized in that a receiving part is provided. 2. The lightning arrester according to claim 1, wherein the pressing spring is disposed between the one electrode that is tightened with a nut from both sides of the mounting hole and the zinc oxide element block and has an outer diameter that is the outer diameter of the zinc oxide element. A lightning arrester characterized by being smaller.

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