JP2003051222A - Optical fiber built-in insulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber built-in insulator which is easy to form, whose structure is simple, and whose manufacturing cost can be reduced, even if the inner core made by FRP where an optical fiber is built in becomes elongated. SOLUTION: In the optical fiber built-in insulator, in which the optical fiber 1 is built, the inner core 3 made by FRP is composed of the divided-type cylindrical body 5, where plural segments 7, 7 having an arch-shaped cross-sectional face whose inner and outer faces are curved outward in the width direction are combined into cylindrical form, and in a cylindrical hole 6 of the divided- type cylindrical body 5, an organic insulating material 11 is filled, and the optical fiber 1 incorporated into the cylindrical hole 6 is fixed.

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to an improvement in an optical fiber built-in insulator. 2. Description of the Related Art Signals are transmitted from overhead transmission lines and the like to ground facilities in order to promptly transmit and handle information on accidents such as ground faults and short circuits in transmission and distribution lines and high-voltage substation facilities. As a means, an insulator incorporating an optical fiber is used. [0003] This optical fiber is made of an FRP to prevent optical transmission loss or disconnection due to local tension or compression when the insulator undergoes bending deformation.
There has been proposed an optical fiber built-in insulator incorporated in a core made of steel. Conventionally, as an FRP core, which is a main part of this kind of insulator, an FRP rod having a spiral groove formed on the outer peripheral surface, in which an optical fiber is accommodated in the spiral groove (Japanese Patent Laid-Open No. 6-162845). ), F having a cylinder formed at both ends and a slit having a depth reaching the center near the center
An RP rod in which an optical fiber is inserted and arranged in the cylinder and the bottom of the slit (JP-A-2000-27695)
No. 8), an optical fiber is inserted into a seamless insulating cylinder made of FRP, filled with an organic insulator, and embedded therein (Japanese Patent Laid-Open No. 9-259669). [0004] However, the above F
A spiral groove is formed on the outer peripheral surface of the RP rod,
Providing a slit near the center in the middle of the rod made is expensive as post-processing after the FRP rod is formed, and the cost of the optical fiber built-in insulator increases. In the case of forming a seamless insulating tube made of FRP, glass fiber is woven or wound around the outer periphery of a mandrel (core for forming the center tube hole of the insulating tube), and the glass fiber is wound. The maximum length of the insulating cylinder that can be formed due to the limitation of the mandrel length is 2-3 m because it is formed by solidifying with resin.
It is not easy to form a long insulating cylinder made of FRP, which is required for an optical fiber built-in insulator for an ultra-high voltage transmission line. Therefore, it is conceivable to increase the length by connecting a plurality of short insulating cylinders in multiple stages. However, since the insulating cylinders need to be aligned and firmly connected, the structure becomes complicated.
In addition, FRP molded by a drawing method that is easy to process
It is conceivable to form a long insulating cylinder by providing a center hole in a long rod-shaped body made of a material. However, providing the center hole is a post-processing step, and is therefore expensive. For this reason, it is not preferable to form a long insulating cylinder by any method, because the cost of the insulator with a built-in optical fiber increases. SUMMARY OF THE INVENTION An object of the present invention is to make it easy to form an FRP core into which an optical fiber is incorporated, even if the core becomes long, to have a simple structure, and to reduce the manufacturing cost of the insulator. It is an object of the present invention to provide an optical fiber built-in insulator. [0006] In order to solve the above-mentioned problems, the present invention relates to an optical fiber built-in insulator in which an optical fiber is incorporated in an FRP core. A plurality of FRP tubular segments each having an arc-shaped cross section whose inner and outer surfaces are curved outward in the width direction, and each of which is formed of a divided tubular body. The hole is filled with an organic insulator, and the optical fiber incorporated in the cylindrical hole is fixed. As described above, since the FRP core is formed of the split-type cylindrical body having the above-described structure, the structure is simplified. In addition, since the shape of the plurality of FRP cylindrical segments constituting the split-type cylindrical body is not cylindrical but rod-shaped,
Even if these cylindrical segments are elongated, they can be formed by a drawing method that is easy to form. Therefore, even if the length of the core made of a divided cylindrical body obtained by combining these cylindrical segments into a cylindrical shape becomes long, it can be obtained easily and inexpensively, and the manufacturing cost of the optical fiber built-in insulator can be reduced. it can. Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of an optical fiber built-in insulator according to the present invention, FIG. 2 is a partially omitted perspective view of a split-type cylindrical body constituting an FRP core which is a main part of the optical fiber built-in insulator of FIG. FIG. 3 is a partially omitted exploded perspective view showing a plurality of FRP cylinder segments constituting the split-type cylinder body of FIG. The optical fiber built-in insulator of this embodiment has an FRP core 3 into which the optical fiber 1 is incorporated. As shown in detail in FIG. 3, the core 3 is a solid rod-shaped body made of two FRPs having a semicircular cross section whose inner and outer surfaces are curved outward in the width direction. Segments 7, 7
, As shown in FIG. [0010] As shown in FIG.
The two cylindrical segments 7, 7 are opposed to each other, and the widthwise side end surfaces of the cylindrical segments 7, 7 are abutted against each other and assembled into a cylindrical shape, so that the cylindrical segments 7, 7 are disassembled separately. In order to prevent such a problem, a fastening member 9 such as a wire, a string, a band, or the like is spirally wound around the outer periphery of the cylindrical body segments 7, 7 and fastened and fixed. As described above, the two cylindrical segments 7, 7
Is preferable because the number of constituent parts is small, the work of aligning and assembling the cylindrical segments 7, 7 is easy, and the number of steps is reduced. For example, as shown in FIG. 2, two optical fibers 1 and 1 are inserted and incorporated into a cylindrical hole 6 of a split-type cylindrical body 5 constituting the core 3, and have a predetermined length. It is pulled outward from both ends of the core 3 by an extra length. As shown in FIG. 1, an organic insulator 11 such as silicone rubber, urethane rubber, or epoxy resin is filled in the cylindrical hole 6 of the split-type cylindrical body 5 so as not to form a void. Are fixed so that the optical fibers 1 and 1 incorporated in the optical fiber do not move. Thus, even if the insulator undergoes bending deformation, the optical fibers 1 and 1 are not locally subjected to tension or compression, and
Optical transmission loss and disconnection can be prevented.
In addition, moisture and other foreign substances are less likely to enter the cylindrical hole 6, and electrical insulation can be further enhanced. As shown in FIG. 1, terminal fittings 13 having insulator support holes 14 and optical fiber lead-out holes 15 are fitted around outer circumferences of both ends of the divided cylindrical body 5 constituting the core 3. It is attached by caulking by compression from the outside of the bracket, bonding, or the like. Then, the extra length of the optical fibers 1 and 1 pulled out from the split type cylindrical body 5 is pulled out through the optical fiber drawing hole 15 of the terminal fitting 13. It is to be noted that, if the organic insulating material 11 such as the silicone rubber or urethane rubber is also filled in the optical fiber lead-out hole 15 of the terminal fitting 13, it is possible to reliably prevent moisture from entering the terminal fitting 13. This is desirable because the insulating property of the core 3 is improved. [0013] The divided cylinder 5 constituting such a core 3
In a state where the terminal fittings 13 are attached to both ends of the terminal, the folds made of an elastic insulating material such as silicone rubber, ethylene propylene rubber, etc. The attached insulating cover 17 is provided by molding or the like. An annular fold (shade) 18 is integrally formed on the outer peripheral surface of the fluted insulating cover 17 so as to protrude from the cover 17 at a predetermined interval in the longitudinal direction of the cover 17. The optical fiber built-in insulator of the above embodiment has the above-described configuration. In the optical fiber built-in insulator of the above embodiment, the divided cylindrical body 5 as the core 3 is combined with the two cylindrical segments 7, 7 in a cylindrical shape, and these cylindrical segments 7, Although the fastening member 9 is formed by spirally winding it around the outer periphery of 7, it can be formed by other methods. For example, the split cylinder 19 shown in FIG.
Combine the two cylindrical segments 7, 7 into a cylindrical shape,
A circular ring 21, for example, a commercially available C-type retaining ring, is fitted around the outer circumference of the cylindrical segments 7, 7 at predetermined intervals along the longitudinal direction of the cylindrical segments 7, 7. This is an example formed by mounting. FIG.
The split-type cylindrical body 23 shown in (b) is obtained by combining the two cylindrical body segments 7, 7 into a cylindrical shape, and then bonding the butted surfaces of the two cylindrical body segments 7, 7 with an adhesive 25. This is an example of forming. The split-type cylinders 5, 1
When forming 9 and 23, two cylindrical segments 7,
It is preferable to form the butting surface 7 on the concave / convex fitting surface (not shown) because it becomes easier to combine the cylindrical segments 7 and 7 into a cylindrical shape. As described above, since the FRP core 3 is composed of the divided cylindrical bodies 5, 19, and 23 having the above-described structure, the structure is simplified. In addition, the shape of the two FRP cylinder segments 7, 7 constituting the split-type cylinders 5, 19, 23 is not cylindrical but rod-shaped. It can be formed by a drawing method that can be easily formed. Therefore, the divided cylinders 5, 19, 2 in which these cylinder segments 7, 7 are combined in a tubular shape.
Even if the core 3 made of FRP made of FRP 3 becomes long, it can be obtained easily and inexpensively, and the manufacturing cost of the insulator with a built-in optical fiber can be reduced. The split cylinders 5 and 1 constituting the core 3
Each of 9, 23 is formed by combining two cylindrical segments 7, 7 made of FRP having a semicircular cross section in a cylindrical shape, but the invention is not limited thereto. For example, as shown in FIG. 5 (a), the split-type cylindrical body 27 is formed by three FRPs having a sectoral arc-shaped cross section with a sectoral opening angle of 120 degrees.
The cylindrical segments 29, 29 are formed by combining them into a cylindrical shape, and as shown in FIG. 5 (b), the split-type cylindrical body 31 is divided into a sector-shaped cross section having a sector opening angle of 90 degrees. FRP cylinder segments 33, 33 having
May be formed by combining them into a cylindrical shape, or may be formed by combining multi-part cylinder segments into a cylindrical shape. As described above, when the number of the segments for the cylinder increases to three or more, the cross-sectional area of the segments for the cylinder decreases, and the cross-sectional shape becomes a fan-shaped arc shape close to a rectangular shape. The drawing process becomes easier.
Therefore, the manufacturing yield is improved, and the long core 3 can be obtained at lower cost, which is preferable. As described above, according to the present invention,
Since the FRP core is composed of a plurality of FRP cylinder segments each having an arc-shaped cross section in which the inner and outer surfaces are curved outward in the width direction, the FRP is formed of a split-type cylindrical body,
The structure becomes simple. In addition, the shape of the plurality of FRP cylindrical segments constituting the split-type cylindrical body is not cylindrical but rod-shaped, so that even if these cylindrical segments are elongated, they can be easily formed. Become. Therefore, even if the length of the core made of a divided cylindrical body obtained by combining these cylindrical segments into a cylindrical shape becomes long, it can be obtained easily and inexpensively, and the manufacturing cost of the optical fiber built-in insulator can be reduced. it can.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of an embodiment of an optical fiber built-in insulator according to the present invention. FIG. 2 is a view showing a main part of the optical fiber built-in insulator of FIG.
It is a partially omitted perspective view which shows the division | segmentation type cylindrical body which comprises the core made of P. 3 is a partially omitted exploded perspective view showing a plurality of FRP tubular body segments constituting the split-type tubular body of FIG. 2; FIGS. 4A and 4B are partially omitted perspective views showing two examples of a divided cylinder different from the divided cylinder shown in FIG. FIGS. 5A and 5B are schematic plan views showing two examples of a divided cylinder different from the divided cylinder shown in FIGS. [Description of Signs] 1 Optical fiber 3 Core 5, 19, 23, 27, 31 Split-type cylinder 6 Cylindrical hole 7, 29, 33 Segment for cylinder 9 Tightening member 11 Organic insulator 13 Terminal fitting 14 Insulator support Hole 15 Hole 17 for drawing out optical fiber 17 Insulated covering 18 with folds 18 Fold 21 Circular ring 25 Adhesive

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Claims (1)

Claims: 1. An optical fiber built-in insulator in which an optical fiber is incorporated in an FRP core, wherein the FRP core has an arc whose inner and outer surfaces are curved outward in the width direction. It is composed of a divided cylindrical body in which a plurality of FRP cylindrical segments having a cross section of a shape are combined in a cylindrical shape, and an organic insulator is filled in a cylindrical hole of the divided cylindrical body, and the inside of the cylindrical hole is filled. An optical fiber built-in insulator, wherein an optical fiber incorporated in the insulator is fixed.