JP2997348B2 - Insulator with built-in optical fiber with cable outlet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a built-in optical fiber having a cable lead-out portion used for extracting an optical signal from an optical CT attached to a bus at a substation or the like to a ground side via a metal-coated optical fiber cable. It is related to insulators.

[0002]

2. Description of the Related Art Conventionally, in order to extract an optical signal from an optical CT attached to a bus at a substation or the like to the ground side, FIG.
As shown in (1), a drawer box 2 is attached to the head of an insulator 1 with a built-in optical fiber, and a metal-coated optical fiber cable 3 is pulled out from the drawer box 2 and directly connected to an optical CT 5 of a bus 4.

As the metal-coated optical fiber cable 3, a cable whose outer shell is made of aluminum is generally used from the viewpoint of weather resistance. It is difficult to perform on-site within a short power outage construction time. Therefore, when newly installing an optical CT in an existing substation, the positions of the optical CT 4 and the optical fiber built-in insulator 1 are determined by photographing the state of the live bus in advance by photographing or the like. After estimating the length of the metal-coated optical fiber cable 3, the metal-coated optical fiber cable 3 cut in accordance with the length is created at a factory and installation work is performed.

However, such a method inevitably causes an error in the length of the metal-coated optical fiber cable 3, so that
In some cases, the metal-coated optical fiber cable 3 becomes too long, resulting in an unpleasant appearance, or the metal-coated optical fiber cable 3 sags and hinders other devices. In addition, this type of equipment needs sufficient strength even when the wind speed of 40m / sec blows,
When the metal-coated optical fiber cable 3 receives wind, a large tensile force acts directly on the draw-out box 2, so that there is also a problem that the reliability with respect to airtightness and waterproofness is low.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems, and enables a metal-coated optical fiber cable to be always drawn to an appropriate length without requiring length adjustment at a construction site. The present invention has been completed to provide an optical fiber built-in insulator having a cable lead-out portion which does not impair the reliability of airtightness and waterproofness even when a strong wind blows.

[0006]

An object of the present invention is to provide an airtight box and a cable connection box at the upper end of an insulator with a built-in optical fiber, and connect an optical fiber and a metal-coated optical fiber cable inside the cable connection box. In addition, the metal-coated optical fiber cable has a cable lead-out portion, which is turned around an appropriate number of times inside a hollow shield ring attached to the upper part of the airtight box, and is drawn out from the cutout portion to the outside. This can be solved by an insulator with a built-in optical fiber.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail with reference to the embodiments shown in FIGS. In FIG. 2, 1 is an insulator with a built-in optical fiber, 6 is an airtight box attached to the head thereof via an O-ring, 7 is a shield ring attached to the lower side of the airtight box 6 via a stay 8, 9
Is an upper shield ring attached to the upper part of the airtight box 6.

Reference numeral 10 denotes an optical fiber drawn out of the central hole of the optical fiber built-in insulator 1 into the hermetic box 6.
The optical fiber 10 is guided via an optical airtight connector 11 into a waterproof cable connection box 12 adjacent to the airtight box 6. The end of the cable connection box 12 is connected to the metal-coated optical fiber cable 3 at the clamp 13. 14 and 15 are zeolite boxes for absorbing moisture, and 16 is a fiber pressing plate provided in the cable connection box 12.

In this manner, the metal-coated optical fiber cable 3 pulled out from the cable connection box 12 to the outside.
Is guided into a hollow shield ring 9 attached to the upper part of the airtight box 6. The shield ring 9 is a ring made of an aluminum alloy having a shape in which an inner upper half portion is cut out as shown in the upper right part of FIG. 3, and is conventionally installed to prevent electric field concentration. In the present invention, the metal-coated optical fiber cable 3 is circulated an appropriate number of times inside the hollow shield ring 9 and then pulled out from the cutout portion.

[0010] Stoppers 17 are provided at appropriate intervals inside the shield ring 9, and a clamp 18 is attached to draw out the metal-coated optical fiber cable 3 in a required direction. In the embodiment, the clamp 18 is fixed by a bolt 19 and its mounting direction is 90 degrees.
° can be moved at a time.

[0011]

The optical fiber built-in insulator having the cable lead-out portion of the present invention thus configured is used for extracting an optical signal from the optical CT attached to the bus at the substation or the like to the ground. As described above, it is difficult to adjust the length of the metal-coated optical fiber cable 3 on site, but in the present invention, the metal-coated optical fiber cable 3 is provided with a sufficient extra length to shield the metal-coated optical fiber cable 3 with a shield ring. 9, the metal-coated optical fiber cable 3 can always be laid in an appropriate length according to the situation at the site only by adjusting the position of the pull-out and the position of the clamp 18.

In the insulator with a built-in optical fiber having the cable lead-out portion of the present invention, since the metal-coated optical fiber cable 3 goes around inside the shield ring 9 and is drawn into the cable connection box 12, the tensile force due to strong wind is obtained. Acts on the metal-coated optical fiber cable 3,
No load acts on the cable connection box 12. For this reason, there is no possibility that waterproofness and airtightness may be reduced, and high reliability can be obtained.

Furthermore, in the present invention, since the metal-coated optical fiber cable 3 is housed inside the shield ring 9, there is no concern about visible corona, and since the existing shield ring 9 is used, the metal-coated optical fiber is used. No extra space is needed to accommodate the cable 3,
The upper structure of the optical fiber built-in insulator 1 can be made the same size as the conventional one.

[0014]

As described above in detail, according to the present invention, the metal-coated optical fiber cable is made to make an appropriate number of turns inside the existing shield ring attached to the upper part of the hermetic box and then to be pulled out. Therefore, the metal-coated fiber optic cable can always be pulled to the appropriate length without the need to adjust the length at the construction site, and the reliability against airtightness and waterproofness is impaired even when strong winds blow There is no advantage. Therefore, the present invention solves the conventional problems and greatly contributes to industrial development.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is a partially cutaway front view showing the embodiment of the present invention.

FIG. 3 is a partially cutaway right side view showing the embodiment of the present invention.

FIG. 4 is a perspective view illustrating a state of laying a conventional metal-coated optical fiber cable.

[Explanation of symbols]

 1 Insulator with built-in optical fiber 3 Metal-coated optical fiber cable 6 Airtight box 9 Shield ring 10 Optical fiber 12 Cable connection box

Claims (1)

(57) [Claims] 1. A a gas-tight box and cabling box provided at the upper end portion of the optical fiber built-in insulators, the cable connection
The optical fiber and the metal-coated optical fiber cable are connected inside the box, and the metal-coated optical fiber cable is turned around an appropriate number of times inside the hollow shield ring attached to the upper part of the hermetic box. An optical fiber built-in insulator having a cable lead-out portion, which is drawn out from the outside.