JP2612932B2 - Multi-stack optical fiber built-in insulator - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-stack insulator with built-in optical fiber.

[Prior art] Conventionally, as an optical fiber built-in insulator, an optical fiber is inserted into a through hole formed in an insulator body, and the optical fiber is filled with a sealing material such as silicone rubber filled inside the through hole. Fixed ones are well known. And as a multi-stack optical fiber built-in insulator formed by joining a plurality of insulator bodies of such an optical fiber built-in insulator,
There are known those in which a connection fitting is attached between the end faces of both insulator bodies to be joined to each other, and those in which both end faces of both insulator bodies are directly joined so as to be in close contact with each other.

[Problems to be Solved by the Invention] However, in the conventional multi-stacked optical fiber built-in insulator, between the end face of the insulator main body and the connection fitting or between the joint end faces of both insulator main bodies directly joined, the inside of the through hole is formed. There is a problem that the filled sealing material exudes, and if the sealing material is thermally expanded in the extruded narrow space when the temperature rises, the insulator body is damaged.

Normally, a connecting bracket is fixed by cement near the outer end surface of the joint end of both insulator bodies, but when rainwater or the like penetrates between the end faces of both insulators into the through hole from the cement portion, a leakage current is generated. A flow ground fault may occur.

Furthermore, if the metal fittings are in direct contact with the end faces of the insulator body, or if the end faces of both insulators are in direct contact with each other, the mechanical shock cannot be absorbed between the end faces of both insulator bodies and an earthquake, etc. If there is, there is a possibility that the end faces joined to each other will collide and be damaged.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide an insulator even when a sealing material seeps between end faces of both insulator bodies and thermally expands. In addition to preventing damage to the main body, it also prevents rainwater or the like from entering between the end faces of the two insulator main bodies from leaking out, causing leakage current to flow into the through-hole and causing a ground fault accident. In particular, it is an object of the present invention to provide a multi-stacked optical fiber built-in insulator capable of absorbing a mechanical shock generated between the end faces of both insulator main bodies and preventing the end faces joined to each other from being damaged.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a method in which a plurality of insulator bodies each having a through hole for inserting an optical fiber are joined to each other, and the insulator body is joined between end faces of both insulator bodies. A sealing member that surrounds the through hole and that elastically contacts the end face of the insulator main body is provided.

 The sealing member may be an O-ring.

Further, the sealing member may be made of a foamable organic material, and may be filled in a gap formed between peripheral portions of the porcelain.

Further, the sealing member is an O-ring attached to both front and back surfaces of a spacer interposed between the end surfaces of the insulator main bodies,
The spacer has an O at a position corresponding to the through hole of the insulator body.
The diameter of the through hole may be smaller than the diameter of the ring, and may be at least larger than the through hole.

[Operation] Between the two insulator bodies, the sealing member surrounds the through hole filled with the sealing material and abuts against the end face of the insulator body resiliently. It absorbs the thermal expansion of the sealing material due to its elasticity. Further, it prevents rainwater or the like from entering from outside to the through hole between the end faces of the two insulator main bodies. Further, the sealing member absorbs a mechanical shock generated between the end faces of the insulator main bodies in the event of an earthquake or the like due to its own elasticity.

Next, an embodiment of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a first embodiment of the present invention. Reference numeral 1 denotes an insulator as an insulator main body which is connected in series in a state where both end surfaces thereof are joined to each other by a connection fitting 2. 3 is a through hole formed in the center of the insulator 1,
Reference numeral 4 denotes an optical fiber penetrating through the through hole 3, and reference numeral 5 denotes silicone rubber as a sealing material filled in the through hole. The silicone rubber 5 is for preventing rainwater or the like from entering the through hole 3 and causing leakage current to flow. In this embodiment, the vicinity of the joint of the through hole 3 is tapered in the same manner as the upper and lower ends. This is for the purpose of absorbing the expansion of the rubber at the end, and is effective as a single product. For this reason, the use of the same porcelain as a single product is used to standardize manufacturing. On the other hand, in the case of a multi-stage product, the hole diameter of the joint may be straight.

As shown in FIG. 2, an O-ring 6 as a sealing member made of an elastic material is interposed between the end faces of the two insulators 1 to be joined. The O-ring 6 is formed to have a larger diameter than the through-hole 3 of the insulator 1, is arranged so as to surround the through-hole 3, and elastically contacts the end faces of the insulators 1.
In the figure, reference numeral 7 denotes cement for fixing the two insulators 1 and the connection fitting 2 to be joined, and prevents rainwater or the like from entering between the end faces of the two insulators 1 from the outside. Reference numeral 8 denotes a packing disposed between the connection fittings 2.
Reference numeral 11 denotes a highly viscous silicone which is filled in a gap S formed between the connection fitting 2, the cement 7, and the periphery of the insulator 1.

Next, the operation of the multi-stack optical fiber built-in insulator configured as described above will be described.

Through-hole 3 into which optical fiber 4 is inserted by O-ring 6
The silicone rubber 5 filled therein is not exposed to water intruding from the cement part, and
Even if the insulator 1 is peeled off, the dielectric strength does not fall and there is no problem of deterioration of the silicone rubber 5 due to water.

In this state, when the insulator 1 thermally expands, the silicone rubber 5 also thermally expands. In this case, since the thermal expansion coefficient of the silicone rubber 5 is usually larger than the thermal expansion coefficient of the insulator 1, the insulator 1 may be damaged by the thermal expansion of the silicone rubber 5 as it is. Since the O-ring 6 interposed between the end faces of the insulator 1 is made of an elastic material, the diameter of the O-ring 6 is increased outward according to the thermal expansion of the silicone rubber 5.

Therefore, the thermal expansion of the silicone rubber 5 is
The insulator 1 is not damaged by the absorption.

Further, even if rainwater or the like infiltrates between the end faces of the two insulators 1 through the gap of the cement 7 provided between the outer surfaces of the joined ends of the two insulators 1 and the connection fitting 2, the end faces of the two insulators 1 Since the O-ring 6 interposed therebetween is in elastic contact with the end face, it prevents rainwater or the like penetrating between the end faces from reaching the through hole 3.

Accordingly, the occurrence of a ground fault can be prevented by the blocking action of the O-ring 6.

Further, when an earthquake or the like occurs, a mechanical impact is generated between the end faces of the joined insulators 1. In this case, if the end surfaces of the two insulators 1 are in direct contact with the surfaces of the connection fittings and the like as in the prior art, the end surfaces of the two end surfaces of the insulators 1 are damaged due to collision of the end faces or the end surfaces with the surfaces of the connection fittings. However, since the O-ring 6 interposed between the end faces of the insulators 1 elastically abuts against the end faces, the shock generated between the end faces is absorbed.

Therefore, the end faces of the two insulators 1 joined to each other do not collide, and even if an earthquake or the like occurs, the insulator 1 is not damaged by the impact.

In addition, the seal of the cement 7 and the O-ring 8 can be omitted by the silicone 11, and water can be prevented from entering between the end faces of the insulator 1, and porcelain cracking due to freezing of water in winter can be prevented.

Although the silicone 11 is used in the present embodiment, the void S may be filled in the void S instead of the silicone 11 by removing the O-ring 6. As a result, the rise in the internal pressure of the insulator due to the expansion of the silicone rubber 5 at a high temperature can be absorbed by the foamable urethane, and water can be prevented from entering from the outside.

Next, FIG. 3 shows a second embodiment of the present invention, and the same members as those in the first embodiment are denoted by the same reference numerals. In the figure, reference numeral 9 denotes a disc-shaped spacer, in which a through hole 10 having the same shape as the through hole 3 of the insulator 1 is formed in the center, and a circumferential groove 11 surrounding the through hole 3 is provided on both front and back surfaces. The O-ring 6 made of an elastic material is positioned in the circumferential groove 11. The O-ring 6 has a lower circular section inserted into the orbiting groove 11, and an upper circular section is exposed from the orbiting groove 11 and is elastically in contact with the end face of the insulator 1.

In the second embodiment, in addition to the functions and effects of the first embodiment, since the spacers 9 are interposed between the end faces of the insulators 1, both spacers are provided even when an excessive load is applied to the upper insulator 1. The end face of the insulator 1 is reliably prevented from colliding and being damaged. In addition, by adjusting the thickness of the spacer 9 inside the porcelain, there is an advantage that the dimensional accuracy of the porcelain and the connection fitting 2 is not required and the assembling becomes easy.

In the first and second embodiments, one optical fiber 4 is inserted, but it is also possible to insert many optical fibers as necessary.

It should be noted that the present invention is not limited to the above embodiments, and can be arbitrarily changed without departing from the spirit of the present invention.

[Effects] As described in detail above, the present invention joins a plurality of insulator bodies having through holes for inserting an optical fiber to each other, surrounds the through holes between the end faces of the two insulator bodies to be joined, and includes the insulator bodies. Since a sealing member elastically abutting against the end face is interposed, even if the sealing material seeps between the end faces of both insulator bodies and thermally expands, such thermal expansion is performed by expanding the diameter of the sealing member. Absorption absorbs damage to the insulator main body, and prevents rainwater, etc. penetrated by the sealing member from reaching the through hole even if rainwater etc. intrudes from the outside between the end faces of both insulator main bodies. The occurrence of a ground fault can be prevented, and the sealing member absorbs the mechanical shock generated between the end faces of both insulator bodies even in the event of an earthquake, so that the end faces of both insulator bodies do not collide. So
An excellent effect that damage of the insulator main body can be prevented is achieved.

[Brief description of the drawings]

FIG. 1 is an overall front sectional view of a first embodiment according to the present invention, FIG. 2 is an enlarged sectional view of an essential part of the same, and FIG. 3 is an enlarged sectional view of an essential part of a second embodiment. An insulator 1 as an insulator body, a through hole 3, an optical fiber 4, an O-ring 6, a spacer 9, and a through hole 10 as sealing members.

Claims (4)

(57) [Claims] 1. A plurality of insulator bodies each having a through hole for inserting an optical fiber are joined to each other, the through hole is surrounded between end faces of both joined insulator bodies, and the insulator bodies are elastically contacted with the end faces of the insulator body. A multi-stack optical fiber built-in insulator characterized by having a sealing member interposed therebetween. 2. The insulator according to claim 1, wherein said sealing member is an O-ring. 3. The multi-stack optical fiber built-in insulator according to claim 1, wherein said sealing member is a foamable organic material and is filled in a gap formed between peripheral portions of the porcelain. 4. The sealing member is an O-ring mounted on both front and back surfaces of a spacer interposed between the end faces of the insulator main bodies. The spacer is provided at a position corresponding to a through hole of the insulator main body. 2. The multi-stack optical fiber built-in insulator according to claim 1, wherein a through hole having a diameter smaller than a diameter of the O-ring and being at least larger than the through hole is formed.