JPH0732526B2 - Construction method of optical fiber composite wire with connector - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for constructing an optical fiber composite electric wire with a connector.

[Prior Art] Usually, an optical fiber composite electric wire has a central portion inside the electric wire with a margin to allow the optical fiber to move freely within the electric wire so that abnormal tension from the electric wire conductor and other external forces do not reach the optical fiber. Although it is inserted into the optical fiber protection space of, the optical fiber composite electric wire can be installed by installing the electric wire in the span between the steel towers and then removing the end of the optical fiber cable exposed at the end of the electric wire. Although it is connected to the end of the optical fiber cable of the optical fiber composite electric wire erected between adjacent diameters, the work of connecting these optical fiber cable terminals to each other at a high place between towers requires skill and is not easy. A connector is attached to the ends of the optical fiber cables at both ends of the electric wire in advance, and the optical fiber composite electric wire with a connector is erected in the span. A construction method has been proposed in which the connectors at the ends of the bull are connected to each other.

[Problems to be solved by the invention]

When aerial wires are towed between the steel towers and installed between them, the wire conductors will elastically expand within the elastic limit due to the traction force during installation and the weight of the wires in the spans. Since the tension is 10 to 20% of the breaking load, it is elastic elongation within the elastic limit, not permanent elongation.

When the optical fiber composite wire with connector is installed, if the wire elastically expands within the elastic limit as described above, the end of the wire also expands, but the tension applied to the wire at the time of installation is not the optical fiber cable inside the wire but its outer circumference. Since it is applied to the electric wire conductor portion, the electric wire conductor on the outer periphery extends, and the end portion of the optical fiber cable exposed from the extended electric wire end is drawn into the electric wire. When the electric wire conductor extends in this manner, the connector at the end of the optical fiber cable may hit the end of the electric wire and the end portion of the optical fiber cable may be stretched in the extending direction of the electric wire end, and the end portion of the optical fiber cable may be cut.

In addition, even if the optical fiber cable is not cut, as a result of the movement of the wire end in the extending direction as described above, the connector hits the wire end and the end of the optical fiber cable is stretched in the extending direction of the wire end. If the elastic elongation of the optical fiber cable is left as it is, a strain remains in the optical fiber cable, and the strain shortens the life of the optical fiber cable.

The present invention solves the above problems and provides a method of erection of an optical fiber composite electric wire with a connector in which distortion due to electric wire pulling force during erection does not remain in an optical fiber cable inserted inside an electric wire. It is intended.

[Means for solving problems]

In order to achieve the above-mentioned object, the method of constructing an optical fiber composite electric wire with a connector according to the present invention comprises an optical fiber composite wire in which an optical fiber cable 3 is inserted inside an overhead wire 2 and an optical fiber is provided outside the wire terminals 2a at both ends. Expose the end of the cable,
The connector 4 is attached to the tip of the exposed end 3a of the optical fiber cable.
The optical fiber cable exposed end 3a is fixed to the electric wire end 2a by the fixing portion 5, and the optical fiber composite electric wire with a connector is installed between steel towers, and then the electric wire end 2a and the optical fiber cable exposed end are attached. Fixing part 5 fixing 3a
Is removed.

[Action]

By exposing the optical fiber cable to the outside of the end of the optical fiber composite wire with connector, the connector can be attached to the end of the optical fiber cable. The connector at the tip can be left outside the wire end.

This connector is used for interconnection with the end of the optical fiber cable of the optical fiber composite electric wire with the connector installed between the adjacent steel towers after the optical fiber composite electric wire is installed between the steel towers.

The traction force applied to the electric wire when the electric wire is erected between the towers causes elastic expansion of the electric wire within the elastic limit. When the end of the wire advances in the direction of extension as the wire extends, the end of the optical fiber cable exposed from the end of the wire is pulled inward toward the end of the wire. By fixing the exposed end of the fiber cable, the exposed end of the optical fiber cable also advances when the wire end advances in the wire extension direction during erection, and is prevented from being drawn into the wire.

When the exposed end of the optical fiber cable fixed to the electric wire end advances in the electric wire extension direction along with the advance of the electric wire end in the electric wire extension direction, the elastic extension within the elastic limit is temporarily applied to the optical fiber cable. However, the strain of elongation caused in the optical fiber cable by the tension load applied to the optical fiber cable due to the elastic elongation of the electric wire at the time of installation is not a permanent elongation or a permanent strain, but a temporary strain within the elastic limit of the optical fiber cable. Elastic elongation. The temporary elastic elongation of the optical fiber cable gradually causes permanent elongation (creep elongation) when the extension period of the optical fiber cable due to the extension of the electric wire extends for a long period of time. When the tensile load on the cable is released, the temporary elastic elongation of the fiber optic cable returns to near zero.

Therefore, after the optical fiber composite electric wire with a connector is erected between steel towers, if the fixing portions 5 that fix both ends 2a of the electric wire and the exposed end 3a of the optical fiber cable are removed, the elastic extension of the electric wire during erection can be achieved. As a result, the tension applied to the optical fiber cable is released, and the elastic extension of the optical fiber cable caused during installation returns to zero, and the elastic strain caused by the elastic extension of the optical fiber cable disappears.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the optical fiber cable 3 is placed in the optical fiber protection space at the center of the electric wire conductor 2 in which conductor wires are twisted together.
Is inserted to form the optical fiber composite electric wire 1. The length of the electric wire conductor 2 of the optical fiber composite electric wire 1 laid between the steel towers is set to a length corresponding to the length of the span plus an increased length due to the electric wire sag. The exposed ends 3a of the optical fiber cable 3 exposed by a predetermined length are formed outside the wire ends 2a at both ends of the optical fiber cable 3, and the connector 4 is attached to the tip of the exposed end 3a of the optical fiber cable. An optical fiber composite electric wire with an optical fiber is constructed.

The optical fiber cable exposed ends 3a exposed from the electric wire ends 2a at both ends of the optical fiber composite electric wire with connector are fixed to the electric wire ends 2a by the fixing portions 5. This fixing is performed by using a solid adhesive such as epoxy resin, or by using a holding metal fitting that can be held so that the optical fiber cable is not damaged by interposing an elastic agent protector such as rubber or plastic on the inner surface. .

After fixing the exposed ends 3a of the optical fiber cable to both ends 2a of the electric wire as described above, this optical fiber composite electric wire with a connector is laid between the steel towers.

Due to the traction force during this installation, elastic extension within the elastic limit occurs in the electric wire conductor 2 and the electric wire terminal 2a also advances and changes in the electric wire expansion direction. However, the exposed end portion 3a of the optical fiber cable protruding outside the electric wire terminal 2a is Since it is fixed to the wire end 2a at the fixing portion 5, when the wire end 2a advances in the wire extending direction, the exposed end 3a of the optical fiber cable also advances and is not drawn into the wire conductor 2. Therefore, a situation in which the mounting portion of the connector 4 at the tip of the optical fiber cable abuts on the wire end 2a and is drawn into the wire to damage the tip of the optical fiber cable does not occur.

As described above, the length of the electric conductor 2 extending within the elastic limit due to the traction force when the optical fiber composite electric wire with a connector is installed in the span is 0.1 to 0.2 of the total electric wire length in the case of an aluminum overhead electric wire.
It will be 3%. Due to the extension of the electric wire conductor 2, the electric wire end 2a
The tension load is also applied to the optical fiber cable 3 fixed by the fixing portion 5 and elastic strain due to elastic elongation occurs.
The strain of elongation caused in the optical fiber cable by the tension load applied to the optical fiber cable due to the elastic elongation of the electric wire at the time of installation is not a permanent elongation or a permanent strain but a temporary elastic elongation within the elastic limit of the optical fiber cable. . Even with this temporary elastic elongation, permanent elongation (creep elongation) gradually occurs in the optical fiber if left as it is for a long time.

Therefore, in order to remove the elastic strain due to the elastic extension of this optical fiber cable, after installing the optical fiber composite electric wire with a connector in the span as described above, apply the tension load due to the elastic extension of the electric wire applied to the optical fiber cable. Open.

To release the tension load applied to this optical fiber cable, first, calculate the amount of expansion within the elastic limit of the wire conductor from the length of the wire laid between the spans, and calculate the length corresponding to this elastic expansion amount. Cut out from the wire end 2b as shown in FIG. The broken line portion 2b in FIG. 2 shows the wire end portion where the wire end 2a extends to 2a 'within the elastic limit, and 3a' shows the optical fiber cable exposed end portion 3a in the elastic limit. 4'indicates the exposed end of the extended optical fiber cable.
The position of the connector at the tip of 3a 'is shown. The electric wire end 2b shown by the broken line is the length to be removed. When cutting the end of the wire, make a cut in the end of the wire, taking care not to damage the optical fiber cable at the center of the wire, and expose the end of the optical fiber cable that was stretched within the elastic limit with the extension of the wire end. Even if the part 3a releases the sticking to the wire end, it will not be drawn further into the wire,
That is, until the elastic strain due to the elastic elongation of the optical fiber cable becomes zero, the electric wire end portion 2b having a length corresponding to the calculated elongation amount of the electric wire is cut and removed little by little.

After cutting and removing the end portion of the electric wire as described above, the fixing portion 5
Is removed, the twisted ends of the twisted wire ends are unwound, and the wire ends of the required length are removed. The arrow attached to the connector 4'shown by the broken line in Fig. 2 indicates the exposed end portion of the optical fiber cable which has extended within the elastic limit as a result of cutting and removing the wire end portion 2b extending within the elastic limit as described above. It shows that the connector 4'at the tip of 3a 'returns to the original position of the connector 4 in the direction of the arrow.

As described above, when both ends of the electric wire and the exposed ends of the optical fiber cable are removed and the tension load applied to the optical fiber cable is released, the position of the electric wire end 2a and the position of the exposed end 3a of the optical fiber cable are Return to the position before stretching when erection. By releasing the tension of this optical fiber cable,
The temporary elastic extension within the elastic limit of the optical fiber cable returns to zero, and the elastic strain of the optical fiber cable due to this elastic extension disappears.

As described above, the optical fiber composite electric wire with a connector is erected for each span of the transmission line, and the terminal portion of the electric wire conductor is supported by the metal fittings attached to the tower arm to support the optical fiber with a connector between adjacent spans. The connector of the end of the optical fiber cable that is connected to the electric wire conductor of the fiber composite electric wire and exposed to the outside of the electric wire is connected to the connector of the optical fiber cable of the optical fiber composite electric wire with a connector having an adjacent diameter.

〔The invention's effect〕

As described above, according to the present invention, the end portion of the optical fiber cable exposed to the outside of the electric wire end of the optical fiber composite electric wire with a connector is fixed to the electric wire end and installed between steel towers, and after the installation, the electric wire end and the optical fiber. By fixing the exposed end of the cable, the optical fiber composite wire with connector was installed in the span, so even if the wire expands within the elastic limit during installation, it will be exposed outside the wire end. There is no possibility that the connector mounting part at the end of the existing optical fiber cable will be pulled into the wire end and broken.

In addition, even if the optical fiber cable is elastically strained due to the expansion within the elastic limit due to the expansion within the elastic limit of the wire when the wire is erected, the both ends of the wire and the exposed ends of the optical fiber cable are fixed after the wire is erected. Is removed to release the tension applied to the optical fiber cable, the elastic strain generated in the optical fiber cable can be returned to zero and the elastic strain can be eliminated after the installation is completed.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of an optical fiber composite electric wire with a connector installed by the method of the present invention, and FIG. 2 is an explanatory diagram of the method of the present invention. 1: Overhead wire 2: Wire conductor 2a: Wire end 3: Optical fiber cable 3a: Exposed end of optical fiber cable 4: Connector 5: Fixed part

Claims (1)

[Claims] 1. An end of an optical fiber cable is exposed outside both ends of an optical fiber composite electric wire in which an optical fiber cable is inserted into an overhead wire, and a connector is attached to the tip of the exposed end of the optical fiber cable. After fixing the exposed end of the optical fiber cable to the electric wire end with the fixing portion, after installing the optical fiber composite electric wire with the connector in the span,
A method for constructing an optical fiber composite electric wire with a connector, characterized in that the fixing portion that fixes the end of the electric wire and the exposed end of the optical fiber cable is removed.