JP2003332108A - Lightning arrester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate steps of an adhesion, winding or curing to automate the assembly. <P>SOLUTION: A plurality of zinc oxide elements 15 are laminated between a pair of supporting metal fittings 14, which are coupled to each other through four FRP rods 16. A groove part 16a is formed in the vicinity of the end of the FRP rod 16, while a through hole 14a is formed in the vicinity of the outer peripheral surface of the supporting metal fittings 14. In a state that the end of the FRP rod 16 is inserted into the through hole 14, electrodes 17 are coupled to the respective supporting metal fittings 14, and the vicinity of the ends of the four FRP rods 16 is pressed to the outside by this electrode 17, whereby a part of the supporting metal fittings 14 is entered into the groove part 16a to constitute an element unit. A polymer-made outer coat 21 is provided so as to enclose the element unit. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lightning arrester, and has an improved structure of an element unit constituting the lightning arrester.

[0002]

2. Description of the Related Art A lightning arrester is composed of a laminated zinc oxide element supported by an insulating member and integrated to form an element unit, and the element unit is covered with a polymer jacket.

There are a conventional example 1 and a conventional example 2 as the structure of the lightning arrester. In Conventional Example 1, an insulating cylinder is used as the insulating member, a zinc oxide element is stacked inside the insulating cylinder and sandwiched by a pair of electrodes, and a hole penetrating the inside and outside of the insulating cylinder is formed. There are a structure for releasing pressure and a structure for releasing pressure by breaking the insulating cylinder by internal pressure without forming a hole. In the conventional example 2, three or more insulating rods are arranged at equal intervals around the stacked zinc oxide elements, and the insulating rods are penetrated through a pair of support plates that sandwich the stacked zinc oxide elements. A nut is screwed onto the end of the rod to release pressure from between the insulating rods.

As a lightning arrester of the conventional example 1, FIGS.
There is one. In FIG. 13, a zinc oxide element 2 is laminated inside the FRP pipe 1, a pair of electrodes 3a and 3b are screwed and sandwiched between the FRP pipe 1, and holes (not shown) penetrating the inside and outside of the FRP pipe 1 are formed. A unit is formed and the element unit is covered with a polymer jacket 7. Reference numeral 4 is an electrode plate, 5 is a disc spring, and 6 is an adhesive applied to the screw portion.

In such a lightning arrester, when the internal pressure rises, pressure is released from a hole (not shown) of the FRP pipe 1. When a mesh pipe is used instead of the FRP pipe, pressure is released from the mesh.

FIG. 14 shows the FRP pipe 1 shown in FIG.
Instead of this, the prepreg sheet 8 is wound into a predetermined thickness and cured to form an element unit. Here, the prepreg sheet is a material in which a glass fiber or the like is knitted in a sheet shape and is impregnated with a resin before being cured. In order to firmly bond the zinc oxide element and the electrode, an outer peripheral groove 9a is formed in the electrode 9, and the prepreg sheet 8 is also wound around the outer peripheral groove 9a.

In such a lightning arrester, when the internal pressure rises, the prepreg sheet 8 is broken to release the pressure.
A prepreg tape may be used instead of the prepreg sheet.

As a lightning arrester of the second conventional example, there is one shown in FIG. This is a support plate portion 10a in which three FRP rods 11 are arranged at equal intervals around the laminated zinc oxide element 2 and formed on a pair of electrodes 10 sandwiching the laminated zinc oxide element 2.
Each FRP rod 11 is penetrated to the FRP rod 1
A nut 12 is screwed onto one end portion to form an element unit.

In such a lightning arrester, pressure is released from between the FRP rods 11 when the internal pressure rises.

[0010]

However, in the lightning arrester of FIG. 13 which uses the FRP pipe, the cost is high because the threaded portion is formed on the electrode for the purpose of firmly connecting the electrodes, and there is a bonding step. There are many processes and it is difficult to automate. If you try to increase the bonding area, the overall length will become longer and the lightning arrestor will become larger.

In the lightning arrester of FIG. 14 using the prepreg sheet, the cost is high because the outer peripheral groove is formed in the electrode, and the number of steps is large and the automation is difficult to wind the prepreg sheet. There are “many steps” to wait for curing, and when trying to increase the adhesion area, the total length becomes longer and “the surge arrester becomes larger”.

In the lightning arrester of FIG. 15 using the FRP rod, since the reinforcing fiber of the FRP rod is divided by the screw processing, the original shear strength of the FRP is remarkably reduced at the threaded portion, which leads to an increase in the size of the threaded portion and the screw. It is necessary to increase the length of the part, and "the lightning arrester becomes larger".

Therefore, an object of the present invention is to provide a lightning arrester that solves such a problem.

[0014]

In order to achieve such an object, the structure of the arrester according to claim 1 is such that a zinc oxide element is laminated between a pair of electrodes, and these electrodes and the zinc oxide element are integrated. In a lightning arrester configured by forming an element unit with an insulator tube surrounding the element unit, a zinc oxide element is laminated between a pair of support fittings, and the zinc oxide elements are laminated in the circumferential direction in the vicinity of the outer peripheral surface of each support fitting. Providing a plurality of through holes at equal intervals, insert both ends of a plurality of insulating rods arranged at substantially equal intervals around the stacked zinc oxide elements into the through holes,
By pressing both ends of the insulating rod to the outside in the radial direction, an electrode that presses a part of the support fitting into a groove formed on the outside of both ends of the insulating rod,
It is characterized in that the element unit is configured by being coupled to the support fitting.

In such a lightning arrester, the electrodes press both ends of the insulating rod inserted into the through holes formed in the support fitting in the radial direction, that is, a part of the support fitting is attached to both ends of the insulating rod. Since the pair of electrodes, the pair of support fittings, and the plurality of insulating rods are integrally coupled with each other in a state where they are fitted in the groove formed on the outside of the case, when bonding as in the conventional case or when winding a prepreg, There is no problem as in the case of screwing both ends of the insulating rod.

According to a second aspect of the present invention, in a lightning arrester, a zinc oxide element is laminated between a pair of electrodes, the electrode and the zinc oxide element are integrated to form an element unit, and an insulator tube surrounding the element unit is provided. In a lightning arrester configured by providing a zinc oxide element between a pair of support fittings, a plurality of through holes are provided at substantially equal intervals in the circumferential direction in the vicinity of the outer peripheral surface of each support fitting, and By inserting both ends of a plurality of insulating rods arranged at approximately equal intervals around the zinc oxide element into the through hole and pressing both ends of the insulating rod inward in the radial direction, a part of the supporting metal fitting is removed. The element unit is configured by providing a ring member that presses a groove formed inside both ends of the insulating rod, and connecting an electrode to each of the support fittings.

In such a lightning arrester, the ring member presses the insulating rod inward in the radial direction, that is, a part of the support fitting is fitted into the groove formed inside both ends of the insulating rod. , Different from claim 1.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a lightning arrester according to the present invention will be described below.

(A) First Embodiment First, the first embodiment is shown in FIG. In the first embodiment,
The structure of the element unit in the arrester is as shown in FIG.

A plurality of zinc oxide elements 15 are laminated between a pair of support fittings 14, and the pair of support fittings 14 are connected to each other via an FRP rod (insulating rod) 16. That is, four FRP rods 16 are arranged at equal intervals around the stacked zinc oxide elements 15, and both ends thereof are connected to the respective support fittings 14.

The respective connecting parts are as follows. First, the cross-sectional shape of the FRP rod 16 is rectangular as shown in FIG. 3, and grooves 16a are formed near both ends thereof. The groove portion 16a is formed only on the outer side, and a part of the support metal fitting 14 enters the groove portion 16a, and FR
The movement of the P rod 16 in the axial direction is prevented. Therefore, four through holes 14a that penetrate the support fitting 14 are formed. The shape of the through hole 14a is the FRP rod 16
3A, which is the cross-sectional shape of FIG. 3A, has a rectangular shape slightly larger than the cross-sectional shape obtained by adding the length corresponding to the depth of the groove 16a in the radial direction. Through hole 14a
In order to press the ends of the four FRP rods 16 inserted in the outer side in the radial direction at the same time, the electrodes 17 are attached to the support fittings 14.
Is bound to. The electrode 17 has a small diameter portion 17a and a large diameter portion 1
7b, the electrode 17 is coupled to the support fitting 14 via the four bolts 18 in a state where the small diameter portion 17a is pushed inside the tips of the four FRP rods 16. As described above, the pair of electrodes 17, the pair of support fittings 14, the four FRP rods 16, and the plurality of zinc oxide elements 15 are integrated. In addition, 17c is a tap hole.

An electrode plate 20 is sandwiched between the support fitting 14 and the zinc oxide element 15, and a pressure bolt 19 for pressing the electrode plate 20 to apply tension to the FRP rod 16 has a shaft center of the support fitting 14. Screwed into position. A disc spring (not shown) is provided between the zinc oxide elements 15. The element unit is constructed in this way, and
As described above, the polymer jacket (insulator tube) 21 is molded so as to surround the element unit.

In such a lightning arrester, gas is released from between the FRP rods 16 during pressure release.

(B) Second embodiment Next, a second embodiment is shown in FIG.

This embodiment differs from the embodiment shown in FIG. 2 only in the electrode 17. The electrode 17 is not divided into a large-diameter portion and a small-diameter portion as in FIG. 2, but only the small-diameter portion. Therefore, the pitch circle of the bolt 18 for connecting the electrode 17 to the support fitting 14 is smaller than that in FIG. 2, and the number of the bolt 18 is reduced from four to two.

Since the outer diameter of the electrode 17 is smaller than that in FIG. 2, the end surface of the FRP rod 16 and the end surface of the support fitting 14 near the outer peripheral surface are visible when viewed from the axial direction.

The other structure and operation are the same as those of the first embodiment, and therefore the description thereof is omitted.

(C) Third Embodiment Next, FIG. 5 shows an essential part of the third embodiment. In this embodiment, only the cross-sectional shape of the FRP rod is changed from that of the first embodiment, so only the parts different from the first embodiment will be described.

As shown in FIG. 5A, the FRP rod 1
6 has a circular cross section. This FR
The shape of the P rod 16 is shown in FIG. Groove 16a in this case
As, a circumferential groove is formed. And through hole 1
Also as 4a, four circular through holes having an outer diameter dimension slightly larger than the outer diameter dimension of the FRP rod 16 and having an inner diameter dimension are formed.

Since the other structure and operation are the same as those of the first embodiment, the description thereof will be omitted.

When the FRP rod 16 having a circular cross section in which the groove 16a is formed only on one side as shown in FIG. 7, is used,
The square through hole 14a having a diameter slightly larger than the square having the diameter of the FRP rod 16 as one side is formed.

(D) Fourth Embodiment Next, FIG. 8 shows a main part of the fourth embodiment.

Also in this embodiment, the FRP rod is changed to the same shape as the FRP rod used in FIGS.
The description of the configuration and operation is omitted.

Even in this case, the configuration using the FRP rod 16 of FIG. 7 can be changed as described above.

(E) Fifth Embodiment Next, FIGS. 9 and 10 show the essential parts of the fifth embodiment. In this embodiment, the end portion of the FRP rod 16 shown in FIG. 10 is pushed to the inside and fixed instead of being pushed to the outside and fixed to a support fitting as in the first embodiment. is there.

A ring member 22 is provided to push the ends of the four FRP rods 16 inward. The ring member 22 is provided on the support fitting 14 so as to bundle the ends of the FRP rod 16. Unlike the first to fourth embodiments, the groove portion 16a formed at the end of the FRP rod 16 is arranged on the inner side, and a part of the support fitting 14 enters the groove portion 16a. There is. The electrode 17 is coupled to the support fitting 14 without the small-diameter portion 17a contacting the FRP rod 16.

The other structure and operation are the same as those of the first embodiment, and the description thereof will be omitted.

As in the second embodiment, the electrode 17
Can have a shape with no step and no large diameter portion.

(F) Sixth Embodiment Finally, the sixth embodiment will be described.

The sixth embodiment has four FRP rods 16
In the lightning arrester shown in FIG. 9, the FRP rod 16 having the circular cross section shown in FIG. 11 and the circular through hole 14a shown in FIG. 5 are provided instead of the FRP rod 16 having the rectangular cross section. , Illustration is omitted.

The electrode 17 may be formed in a shape having no step and no large diameter portion.

In addition, a part of FIG. 9 which is the sixth embodiment is modified to use a FRP rod 16 having a circular cross section in which a groove portion 16a is provided on only one side as shown in FIG. 12, and the diameter of the FRP rod 16 is changed. You may make it provide the square through hole slightly larger than the square used as one side. Also in this case, the electrode 17 may have a shape having no step and no large diameter portion.

In the first to sixth embodiments, the number of insulating rods is not limited to four and may be any number, and the number may be increased or decreased according to the bending strength specifications. In addition, the length of the arrester and the length of the element unit may increase or decrease depending on the rated voltage and contamination specifications. However, a binding member having substantially the same shape as the support member is provided between the pair of support members so that the FRP rod can be inserted into the through hole. Alternatively, a ring member for bundling the FRP rods may be provided as necessary to prevent the FRP rods from bending. In addition, a plurality of integrated element units may be connected in series.

[0044]

As is apparent from the above description, claim 1
According to the lightning arresters of to 5, the zinc oxide elements laminated between the pair of support fittings are integrally connected by a plurality of insulating rods, and the support fittings and the insulating rods are connected in the vicinity of the outer peripheral surface of the support fitting. The insulating rod inserted into the through hole is pressed in the radial direction by the electrode or ring member connected to the supporting metal fitting, so that part of the supporting metal fitting can be inserted into the groove of the insulating rod to connect the insulating rod. Simple and cheap to manufacture. Further, even in the case of the arrester with a high rated voltage, if a plurality of element units are connected, common parts can be achieved.

In addition, as compared with the conventional lightning arrester, the bonding step, the winding step, the curing step, etc. are unnecessary, so that the assembly time can be shortened and the assembly can be automated. Also, unlike the conventional method, it is not necessary to lengthen the electrode for the purpose of increasing the adhesive strength, and it is not necessary to increase the screw size as in the case where both ends of the insulating rod are screwed together. Can be realized. Further, management of an unused prepreg material is complicated because it has an expiration date, but such management is unnecessary. In addition, there is no need to process holes for outgassing.

[Brief description of drawings]

1 relates to a first embodiment of a lightning arrester according to the present invention,
(A) is a front sectional view and (b) is a plan view.

2A and 2B relate to a main part of a first embodiment of a lightning arrester according to the present invention, in which FIG. 2A is a plan view and FIG.

3A and 3B relate to the FRP rod of the first embodiment of the lightning arrester according to the present invention, where FIG. 3A is a plan view and FIG. 3B is a front view.

FIG. 4 is a plan view and (b) a front sectional view of a main part of a lightning arrester according to a second embodiment of the present invention.

5A and 5B relate to a main part of a lightning arrester according to a third embodiment of the present invention, in which FIG. 5A is a plan view and FIG.

6A and 6B relate to an FRP rod of a third embodiment of a lightning arrester according to the present invention, (a) is a plan view and (b) is a front view.

7A and 7B relate to an FRP rod obtained by partially improving the third embodiment of the lightning arrester according to the present invention, FIG. 7A is a plan view, and FIG. 7B is a front view.

8A and 8B relate to a main part of a fourth embodiment of the lightning arrester according to the present invention, where FIG. 8A is a plan view and FIG. 8B is a front sectional view.

9A and 9B relate to a main part of a fifth embodiment of a lightning arrester according to the present invention, where FIG. 9A is a plan view and FIG. 9B is a front sectional view.

FIG. 10 is an FRP of a fifth embodiment of the arrester according to the present invention.
FIG. 5A is a plan view of the rod, and FIG.

FIG. 11 is an FRP of Embodiment 6 of the arrester according to the present invention.
FIG. 5A is a plan view of the rod, and FIG.

FIG. 12 relates to an FRP rod which is a partially improved version of the sixth embodiment of the arrester according to the present invention, (a) is a plan view and (b) is a front view.

FIG. 13 is a cross-sectional view of a lightning arrester according to Conventional Example 1.

FIG. 14 is a sectional view of a lightning arrester according to Conventional Example 1.

FIG. 15 is a cross-sectional view of a lightning arrester according to Conventional Example 2.

[Explanation of symbols]

14 ... Support bracket 14a ... through hole 15 ... Zinc oxide element 16 ... FRP rod 16a ... Groove 17 ... Electrode 18 ... Bolt 21 ... Jacket 22 ... Ring member

Claims (5)

[Claims] 1. A zinc oxide element is laminated between a pair of electrodes,
In a lightning arrester configured by integrating these electrodes and a zinc oxide element to form an element unit and providing an insulator tube surrounding the element unit, a zinc oxide element is laminated between a pair of support fittings, and each support fitting is attached. A plurality of through-holes are provided at substantially equal intervals in the circumferential direction in the vicinity of the outer peripheral surface of, and both ends of a plurality of insulating rods arranged at substantially equal intervals around the stacked zinc oxide elements are inserted into the through-holes. , By pressing both ends of the insulating rod to the outside in the radial direction, a part of the supporting metal fitting is pressed to the groove formed on the outside of both ends of the insulating rod, and the electrode is attached to the supporting metal fitting. A lightning arrester characterized by being connected to form the element unit. 2. A zinc oxide element is laminated between a pair of electrodes,
In a lightning arrester configured by integrating these electrodes and a zinc oxide element to form an element unit and providing an insulator tube surrounding the element unit, a zinc oxide element is laminated between a pair of support fittings, and each support fitting is attached. A plurality of through-holes are provided at substantially equal intervals in the circumferential direction in the vicinity of the outer peripheral surface of, and both ends of a plurality of insulating rods arranged at substantially equal intervals around the stacked zinc oxide elements are inserted into the through-holes. , A ring member is provided, which presses both ends of the insulating rod inward in the radial direction, thereby pressing a part of the support fitting into a groove formed inside both ends of the insulating rod. A lightning arrester characterized in that the element unit is configured by connecting an electrode to the supporting metal fitting. 3. The lightning arrester according to claim 1, wherein a part of the outer diameter of the electrode in the axial direction is set to be substantially the same as the outer diameter of the support fitting. 4. The arrester according to claim 1, wherein the insulating rod has a rectangular sectional shape. 5. The lightning arrester according to claim 1, wherein the insulating rod has a circular cross section and the groove is formed over the circumference.