JP2002247744A - Rod-shaped insulating spacer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rod-shaped insulating spacer which has light weight and sufficient strength (superior workability) and is capable of restraining a state of surface soilure and reducing or eliminating maintenance work. SOLUTION: A body 10 of this spacer is formed by providing a coverture 2 for preventing soilure on the side surface of a rod-shaped core material 1 made of a glass fiber-contained thermoplastic resin, and a wire-installation member 3 is mounted to both ends of the spacer body 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rod-shaped insulating spacer for preventing a wire from hanging down when the wire is broken by being bridged between the wires.

[0002]

2. Description of the Related Art In general, a rod-shaped insulating spacer is provided between electric wires such as high-voltage distribution lines to prevent the electric wires from hanging down on the ground when the electric wires are broken due to stress or corrosion. . As the rod-shaped insulating spacer, a so-called porcelain spacer having a porcelain rod as a main body is exclusively used. However, such a porcelain spacer is heavy and easily cracked. Have the problem of being bad.

[0003]

SUMMARY OF THE INVENTION In view of the above circumstances, an object of the present invention is to provide a rod-shaped insulating spacer which is lightweight, has sufficient strength, and is excellent in workability. It is another object of the present invention to provide a rod-shaped insulating spacer that has excellent weather resistance and can withstand outdoor use. It is another object of the present invention to provide a rod-shaped insulating spacer that can be easily manufactured into a desired shape and that reduces the manufacturing cost.

[0004]

Means for Solving the Problems The present inventors have determined the basic performance required of a rod-shaped insulating spacer, namely, mechanical strength (impact load resistance) and electric properties (insulation, tracking resistance, arc resistance). Investigation into the weight reduction and weather resistance of the spacers while taking into account the above considerations). As a result, a rod-shaped core material is made of glass fiber-containing thermoplastic resin, and the outer shell of insulating rubber is coated on the core material to form the spacer body. As a result, it has been found that the basic performance of the spacer can be satisfied, and a significant reduction in weight and excellent weather resistance can be realized. That is, the present invention has the following features.

(1) A rod-shaped insulating spacer which is stretched between electric wires to prevent the electric wires from sagging when the electric wires are broken, wherein the side surface of the rod-shaped core material made of glass fiber-containing thermoplastic resin has weather resistance. A rod-shaped insulating spacer in which a spacer main body is formed by covering with an outer skin, and members for connecting to an electric wire are attached to both ends of the spacer main body. (2) The rod-shaped insulating spacer according to (1), wherein the outer skin having weather resistance is made of insulating rubber. (3) The spacer body is formed by placing a rod-shaped core material obtained by injection molding or extrusion molding of a glass fiber-containing thermoplastic resin in a mold, injection-molding insulating rubber in the mold, and forming a rod-shaped body. The insulating spacer on a rod according to the above (2), wherein an insulating rubber film is applied to a side surface of the core material. (4) The glass fiber-containing thermoplastic resin contains 5 to 60 parts by weight of glass fiber per 100 parts by weight of the modified polyphenylene ether-based thermoplastic resin.
The rod-shaped insulating spacer according to any one of (3). (5) The rod-shaped insulating spacer according to any one of the above (2) to (4), wherein the insulating rubber is a liquid silicone rubber. (6) The rod-shaped insulating spacer according to any one of (1) to (5) above, wherein the member for linking to the electric wire is screwed and attached to an end of the spacer body.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of a rod-shaped insulating spacer of the present invention. FIG. 1 (a) is a front view, and FIG. 1 (b) is a sectional view of a main part. The rod-shaped insulating spacer 100 forms a spacer body 10 by covering a side surface of a round rod-shaped core material 1 made of a glass fiber-containing thermoplastic resin with an outer skin 2 made of insulating rubber. And a member 3 for connection to an electric wire is attached to the cable.

The side surface of the rod-shaped core material 1 is covered with an outer skin 2 made of insulating rubber, except for portions that are screwed into the connecting members 3 on both sides thereof. The outer skin 2 made of insulating rubber is provided for improving weather resistance and / or protecting the core material, and is provided in a region where sufficient weather resistance is required on a side surface of the rod-shaped core material and / or a region to be protected. (In this example, the rod-shaped core material 1 is provided on the entire side surface of substantially the entire length of the bar-shaped core material 1 excluding the portion that is screwed with the linking member 3.) In order to secure a creepage distance for flashover (flashover) measures, disk-shaped caps 2A and 2B protruding in a direction substantially perpendicular to the side surface of the rod-shaped core material 1 are formed on the outer skin 2 made of insulating rubber. The cores 1 are provided alternately at substantially equal intervals in the longitudinal direction.

The connecting member 3 is a spacer (spacer body 1).
It is a member for supporting the connection to the electric wire of 0), and is made of an aluminum forged metal fitting or the like. The connecting member 3 has a base 3A formed with a concave hole 3C for receiving an end of the spacer body 10, and a tongue 3B protruding from the base 3A. A through hole 3b is formed. The concave hole 3C has a two-stage structure of a large-diameter portion 31 for receiving the end of the outer cover 2 made of insulating rubber of the spacer body 10 and a small-diameter portion 32 for receiving the tip of the rod-shaped core material 1. Further, the inner peripheral surface of the small diameter portion 32 is subjected to screw processing (screw processing). On the outer peripheral surface of the distal end portion of the rod-shaped core material 1, a thread and a screw groove corresponding to the thread and the thread groove of the small diameter portion 32 of the concave hole 3 </ b> C are processed (screwed), and the spacer body 10 (the rod-shaped core material) is formed. Each of the connecting members 3 is externally fitted to both ends of 1).
By screwing the small-diameter portion 32 of the concave hole 3C and the tip of the rod-shaped core material 1, the linking member 3 is fixed to both ends of the spacer body 10 (the rod-shaped core material 1).

The connection (ie, mechanical connection) of the rod-shaped insulating spacer of the present invention to an electric wire is usually performed via a relay member having a structure that can be attached to the electric wire itself. FIG. 2 shows an example of this relay member.
Two U-shaped bent parts 21A and 21B facing in the opposite direction of 0 ° C
Are located approximately in the center, and metal wires (for example, SUS) in which the spiral portions 22A and 22B extend left and right from the bent portion of the U-shaped portion
304), and rubber caps (for example, made of EP rubber (ethylene-propylene rubber)) 23 are covered on both ends of the spiral portions 22A and 22B. FIGS. 3 and 4 show a state in which the rod-shaped insulating spacer 100 shown in FIG. That is, the relay members 20 are inserted into the through-holes 3b of the connecting member 3 at both ends of the rod-shaped insulating spacer 100 from one end side thereof, and are passed to the U-shaped bent portion 21A (21B), and the relay members 20 at both ends of the spacer are passed through. By winding the spiral portions 22A, 22B around the electric wires 50A, 50B, the rod-shaped insulating spacer 1 is formed.
00 is connected between the electric wires 50A and 50B.

In the rod-shaped insulating spacer of the present invention, the spacer main body is composed of a rod-shaped core made of glass fiber-containing thermoplastic resin and an outer cover made of insulating rubber, and a conventional porcelain spacer (the spacer main body is made of porcelain) Large) and lighter. In addition, as an insulator for insulating the electric wire from the support when attaching the electric wire to the support, a glass fiber of a long fiber impregnated with a thermosetting resin such as an epoxy resin or an unsaturated polyester resin is formed by a filament winding method or the like. So-called polymer insulators, which are produced by bundling them in a rod shape and heat-curing a thermosetting resin, are in practical use. However, compared to glass fiber-containing thermosetting resins used in polymer insulators, glass fibers (short fibers) are used. The specific gravity of the fiber-containing thermoplastic resin is small, and the rod-shaped insulating spacer of the present invention is lighter than the polymer insulator. That is,
By using a glass fiber (short fiber) -containing thermoplastic resin instead of a glass fiber-containing thermosetting resin, the weight is sufficiently reduced, and the intended workability is improved.

In the example shown in FIG. 1, the rod-shaped core 1 constituting the spacer body 10 has a round bar shape (circular cross section), but may have another cross sectional shape such as a square bar shape (cross section is polygonal). .
In addition, a large and small disk-shaped cap 2 is provided on the outer cover 2 made of insulating rubber for preventing contamination to prevent flashover at the time of contamination.
Although A and 2B are projected, the shape of the shade is not particularly limited. However, a disk shape is preferable because uniform characteristics can be obtained in all directions of 360 ° around the axis of the spacer.

The overall length and outer diameter of the rod-shaped insulating spacer of the present invention,
The dimensions of each member are appropriately determined according to the laying state of the continuous electric wire, the specification of the electric wire, the material of each member constituting the rod-shaped insulating spacer, and the like. As shown in the example of FIG. 1, when providing a shade for flashover countermeasures at the time of contamination,
The size and thickness of the cap are set so that the weight of the cap does not impair the weight reduction of the target spacer. In the example of FIG. 1, the large shade 2A and the small shade 2B are alternately provided. To prevent raindrops from cascading each other).
In addition, as long as the creepage distance (required surface leakage distance) can be sufficiently secured, the arrangement interval (pitch) of the caps is equal to or slightly larger than the overhang length of the caps. It is preferable to set

The connecting members attached to both ends of the spacer body are, in the example of FIG. 1, metal fittings made of aluminum forging, but other metals (for example, stainless steel) and materials other than metals (for example, stainless steel). , Porcelain, etc.). The connecting member 3 in the example of FIG.
Although the connection to the electric wire is performed by using the cable, the cable itself may have a structure that can be attached to the electric wire, and may be configured to be directly connected to the electric wire without using a relay member.

The spacer body is obtained by expanding the diameter of an insulating rubber tube and covering the tube with a rod-shaped core material (formed by injection molding or extrusion molding) made of glass fiber-containing thermoplastic resin coated with an adhesive. How to shrink and adhere,
A rod-shaped core material made of glass fiber-containing thermoplastic resin can be coated with a lubricant such as silicone grease, and then press-fitted and adhered to an insulating rubber tube, but the following method is preferable. First, a rod-shaped core material produced by injection molding or extrusion molding of a glass fiber-containing thermoplastic resin (however, in the extrusion molding, a continuously extruded rod is cut into a predetermined length to obtain a rod-shaped core material). After performing a primer treatment (for example, treatment with a tetraalkoxysilane, a silane coupling agent, or the like), a rod-shaped core material is placed in a mold, and an insulating rubber is injection-molded in the mold (with the rod-shaped core material). Insert molding). As a result, molding (vulcanization, curing) of the insulating rubber and adhesion to the rod-shaped core material are simultaneously performed, and a spacer body having the insulating rubber film adhered to the side surface of the rod-shaped core material is completed. In this method, the formation of the insulating rubber film and the adhesion of the film to the rod-shaped core material can be performed at the same time, so that the working efficiency is good and the manufacturing cost can be reduced as compared with the above two methods. In particular, silicone rubber (LTV (Low Temperature vulcanizing) described later) is used for the insulating rubber.
Type or RTV (Room Temperature vulca
nizing) type silicone rubber)
Molding (vulcanization) can be performed at a relatively low temperature of about 150 ° C., and the production cost can be further reduced. Also, as in the example of FIG. 1, when a cap is projected from the outer surface of the insulating rubber to prevent flashover, the film and the cap can be formed simultaneously by injection molding of the insulating rubber. There is no need to provide a special process, and the shade can be formed with high dimensional accuracy.

In the example shown in FIG. 1, the end of the spacer body 10 (the rod-shaped core 1) and the base 3A of the connecting member 3 are threaded, and the end of the spacer body 10 (the rod-shaped core 1) is formed. Although the connecting member 3 is directly screwed and attached, other mounting structures (for example, holes for inserting pins are formed in the end of the spacer body and the base of the connecting member, respectively, and one is inserted into the other. A structure in which the joint pin is inserted into the pin insertion hole and fixed to each other (pin type), a male screw member (insert screw) is fitted and fixed to the end of the spacer body, and the joint screw is connected to the male screw member. Structure for screwing the base of the member (insert screw type)
Etc.) may be used. In addition, the mounting structure of terminal fittings commonly used in conventional porcelain spacers (a structure in which the end of the spacer is inserted into a concave hole formed in the base of the terminal fitting and the gap is solidified with cement (plug-in type)) The mounting structure of terminal fittings commonly used in conventional polymer insulators (made of glass fiber-containing thermosetting resin) (provided with a protruding piece that can be bent and deformed on the terminal fittings and fixed by crimping to the insulator body (compression type) ), A wedge, a conical cone, or the like is inserted into the concave hole of the terminal fitting, an adhesive is further poured, and the end of the insulator main body is press-fitted therein. However, among these, it is preferable that the base of the linking member is directly screwed to the end of the spacer main body shown in the example of FIG. 1. In addition, it is possible to obtain a sufficient mechanical strength (the strength of the mounting portion) while achieving a compact and lightweight product after assembly. The mounting structure by screwing has not been employed in conventional porcelain spacers or polymer insulators. This is the main body (spacer body made of porcelain, insulator body made of thermosetting resin containing glass fiber)
The reason for this is that the screw cannot be formed into a complicated shape, and a screw with a certain precision cannot be threaded by secondary processing such as grinding. (The rod-shaped insulating spacer of the present invention has a spacer body whose glass fiber-containing thermoplastic resin is used. It can be formed into a complicated shape, and can be screwed with high precision even by secondary processing such as grinding.)

Further, by using the mounting structure by screwing, the following advantages can be obtained in addition to the above advantages. Disassembly and re-fixing after attaching (fixing) the linking member to the spacer body can be easily performed, and the product obtained by re-fixing has high reliability. Further, if the screws are processed so that the directions in which the screws are loosened are opposite to each other between both ends of the core material, the screwed (fixed) portions are more difficult to loosen. further,
If an adhesive is applied to the threaded portion in advance, the effect of preventing the threaded (fixed) portion from loosening is further improved.

In the present invention, the attachment of the linking member to the spacer body may be performed during the manufacturing process of the spacer body (after forming the rod-shaped core material) or after the manufacturing of the spacer body. .

The thermoplastic resin of the glass fiber-containing thermoplastic resin used for the rod-shaped core material of the present invention includes, for example, modified polyphenylene ether (m-PPE), polybutylene terephthalate (PBT), and polyether ether ketone (PEEK). , Polyphenylene sulfide (PP
S), polyether sulfone (PES), polyarylate (PAR), polyetherimide (PEI) and the like. Among these, prevention of functional deterioration such as mechanical strength, mechanical properties due to moisture absorption and water absorption, insulation properties, etc., dimensional stability during molding, and secondary (adhesion) processing with a skin agent (insulating rubber) From the viewpoint of properties, modified polyphenylene ether (m-PPE) is preferable, and specifically, a polymer alloy of polyphenylene ether and polystyrene resin, a polymer alloy of polyphenylene ether and polyamide resin, polyphenylene ether and styrene-butadiene-
Examples thereof include a polymer alloy of a styrene block copolymer.

The glass fibers are short fibers, and the amount is 5 to 60 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the thermoplastic resin. The glass fiber content is 5
If the amount is less than 10 parts by weight, the mechanical strength and rigidity are insufficient.

As the insulating rubber, any rubber having excellent weather resistance, electrical insulation, ozone resistance and the like and having tracking resistance can be used, and silicone rubber, EVA and the like can be used.
(Ethylene-vinyl acetate copolymer rubber), EPDM (ethylene-propylene-diene copolymer rubber) and the like, and in particular, water repellency, surface electric properties (tracking resistance,
From the viewpoint of arc resistance and the like, it is preferable to use silicone rubber. Furthermore, HTV (hi
gh temperature vulcanizing type (main component is solid or liquid rubber), LTV (Low Temperature vulcanizing)
izing) type (main component is solid or liquid rubber), RT
There is a V (Room Temperature vulcanizing) type (liquid rubber) and the like, but an LTV type and / or RTV that can be formed at a relatively low temperature (about 50 to 150 ° C.) compared to an HTV type (solid or liquid rubber). Liquid silicone rubbers of the type are particularly preferred.

In the insulating rubber, if necessary, additives such as reinforcing fillers, extenders, plasticizers, pigments, crosslinking agents, crosslinking reaction catalysts, metal salts, metal oxides, hydrated metal oxides, etc. A modifier may be added.

[0022]

EXAMPLE A glass fiber-containing modified polyphenylene ether resin containing 30% by weight of glass fiber (Noryl GFN3 (trade name), manufactured by GE Plastics Japan, Inc.) at 280 ° C.
580mm in length and 24mm in diameter
Was obtained. Next, after the both ends (11 mm length region from the end face) of the obtained bar-shaped core material were subjected to screw processing, the bar-shaped core material was placed in a mold for forming a skin heated to 110 ° C. , 2 liquids / LT
V-type liquid silicone rubber (GE Toshiba Silicone, Si
lopre Electro 242) was injected and molded (vulcanized) to produce a spacer body having a shape shown in FIG. 1 in which a skin (thickness: 4.5 mm) of liquid silicone rubber was adhered to the side surface of a rod-shaped core material. The thickness of the two large and small shades provided on the outer skin is 4 mm, the diameters are 75 mm and 95 mm,
The distance between the two large and small shades was 45 mm. Next, the connecting member (aluminum forged metal fitting) shown in FIG. 1 was externally fitted and screwed to both ends of the spacer body to complete a rod-shaped insulating spacer. The distance from the connecting member to the first shade was 39 mm.

The rod-shaped insulating spacer manufactured as described above is about 50% lighter than a conventional porcelain spacer of the same size. Further, the following performance evaluation test was performed on the manufactured rod-shaped insulating spacer.

Commercial frequency flashover test A commercial frequency voltage was applied between both brackets of the spacer by a commercial frequency voltage generator, and the flashover voltage was measured continuously 5 times or more, and the average value was calculated. The flashover voltage was 207 kV, which was a better result than the conventional porcelain spacer (standard value: 139 kV).

Impact Test Using a constant load tensile test apparatus shown in FIG. 5, a load can be applied to a tensile load end using a pulley, and the axial tension and the vertical tension are simultaneously released. This operation generates an impact force of 600 kgf in the axial direction and 5 kg in the vertical direction.
The adjustment was performed so that an impact force of 0 kgf works. As a result, no breakage, no core material (core) dropout, no cracks in metal fittings, etc. occurred, and the spacer had excellent impact load strength.
In FIG. 5, the constant load tensile test apparatus 200 includes
Rod-shaped insulating spacer (sample) 10 fixed on the upper surface
It is configured such that an axial tensile load and a vertical tensile load can be applied to 0. The mechanism for applying an axial tensile load is such that a wire rope L1 provided with a load cell 202 is wound around the tip of a rod-shaped insulating spacer (sample) 100 fixed to an anchoring table 201, and the wire rope L1 is attached to a load support 203. Leverage 204
While the wire rope L2 is connected to the point of action of the lever 204, and a weight 205 is attached to the tip of the wire rope L2, and the wire rope L2 is connected to the pulley 20.
The weight 205 is configured to freely fall along 6. The mechanism for applying a vertical tensile load is the
01 on the upper frame of the support frame 207 erected near
On the other hand, one end of a wire rope L3 provided with a load cell 209 is connected to the tip of a rod-shaped insulating spacer (sample) 100, a weight 210 is attached to the other end of the wire L3, and the wire rope L3 is moved along a pulley 208. The weight 210 is configured to fall freely. Load cells 202 and 209 are connected to recorder 211.

Tracking and Erosion Test A test was conducted under the following conditions in accordance with the method described in IEC 61109. Test time: 1000 hours Applied voltage: 14 kV (creepage distance: 484 mm) Size of test chamber: 10 m ³ or less (exhaust vent: 80 cm ² ) Spray method: atomizer Sodium chloride content: 10 kg / m ³ Spray amount: 0 0.4 / m ³ × 1 hour Particle size: 5 μm to 10 μm Temperature: Conduct salt spray test under the condition of 20 ° C. Sample placement: horizontal and vertical mounting As a result of this test, trips due to overcurrent occurred 3 or more times No core material was exposed due to tracking and / or erosion.

After the sample (spacer) was sufficiently washed with a neutral detergent, the sample was suspended in a room of 8 m ³ , and the nozzle was placed at two places 1 m away from the sample at 45 ° downward from below. Fouling liquid (1 liter of pure water, 22 g of salt, 40 g of powder)
Was injected at a water injection amount of 1 mm / 1 minute, and water was injected for 10 minutes or more, and then a power was applied with a commercial frequency voltage generator for 6.9 kV / 30 minutes or more to measure leakage current. The details of the water injection equipment are as follows. Pump: Iwatani Electric Works (Model: 25ET602) Head: 3.5m, Pumping rate 85L / min Water injection nozzle: Ikeuchi Co., Ltd. (Model: 1 / 8MJJX)
P030S303) As a result of this test, the leakage current was 1 mA or less and the sample had good antifouling property.

Further, the work of actually installing (attaching) the rod-shaped insulating spacer between the high-voltage distribution lines suspended in the viaduct was performed. However, the work can be installed with higher workability than the conventional porcelain spacer. The work time was greatly reduced.

[0029]

As is apparent from the above description, according to the rod-shaped insulating spacer of the present invention, the outer surface of the insulating rubber is provided on the side surface of the rod-shaped core made of glass fiber-containing thermoplastic resin.
Since this is used for the spacer body, it has light weight and sufficient strength without impairing the basic performance of the original spacer,
It has excellent workability compared to conventional porcelain spacers. Also, since the rod-shaped core material is formed by injection molding or extrusion molding, and the outer shell of insulating rubber can be injection-molded to produce the spacer body, the manufacturing cost including the material and processing costs can be reduced more than before. Even complicated shapes can be easily and accurately manufactured.

[Brief description of the drawings]

FIG. 1 shows an example of a rod-shaped insulating spacer of the present invention, wherein FIG. 1 (a) is a front view and FIG. 1 (b) is a sectional view of a main part.

FIG. 2 is a view showing an example of a relay member used for connecting a rod-shaped insulating spacer to an electric wire according to the present invention.

FIG. 3 is a perspective view of a main part showing a state where the rod-shaped insulating spacer of the present invention is connected to an electric wire.

FIG. 4 is an overall view showing a state where a rod-shaped insulating spacer of the present invention is connected to an electric wire.

FIG. 5 is a schematic front view of a constant load tensile tester used for an impact test of the spacer of the example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rod-shaped core material 2 Insulation rubber outer skin 3 Connecting member 10 Spacer body

Continued on the front page (72) Inventor Yoshiji Miyashita 8 Nishinocho, Higashimukaijima, Amagasaki City, Hyogo Prefecture Inside Mitsubishi Electric Wire Industries, Ltd. (72) Inventor Akihiro Yamamoto 663 Mishima, Arita City, Wakayama Prefecture In-house (72) Inventor Atsushi Ohori 663 Minoshima, Arita-shi, Wakayama Prefecture Mitsubishi Cable Industry Co., Ltd.Minoshima Manufacturing Co., Ltd. ) Inventor Shinji Kato 1008 Niibori, Kumagaya-shi, Saitama F-term (reference) in Mitsubishi Cable Industries, Ltd.

Claims (6)

[Claims] 1. A rod-shaped insulating spacer that is stretched between electric wires to prevent the electric wires from sagging when the electric wires are broken, wherein a side surface of a rod-shaped core made of glass fiber-containing thermoplastic resin has a weather-resistant outer skin. A rod-shaped insulating spacer comprising a spacer main body formed by coating with a spacer, and a member for connecting to an electric wire attached to both ends of the spacer main body. 2. The rod-shaped insulating spacer according to claim 1, wherein the outer shell having weather resistance is made of insulating rubber. 3. The spacer body is prepared by placing a rod-shaped core material obtained by injection molding or extrusion molding of a glass fiber-containing thermoplastic resin in a mold, and injecting an insulating rubber into the mold. 3. The rod-shaped insulating spacer according to claim 2, wherein an insulating rubber film is applied to a side surface of the rod-shaped core material. 4. The rod-shaped insulating spacer according to claim 1, wherein the glass fiber-containing thermoplastic resin contains 5 to 60 parts by weight of glass fiber per 100 parts by weight of the modified polyphenylene ether-based thermoplastic resin. . 5. The rod-shaped insulating spacer according to claim 2, wherein the insulating rubber is a liquid silicone rubber. 6. The rod-shaped insulating spacer according to claim 1, wherein a member for linking to the electric wire is screwed to an end of the spacer body.