JPH0344493B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a special overhead wiring method for optical fiber composite overhead wires having a special configuration, and in particular, a method for overhead wiring such that overhead wire tension is not directly applied to the optical fibers. This invention relates to a new overhead line method.

[Prior Art] A conventional optical fiber overhead wire generally has a cross-sectional structure as shown in FIG. It is made by twisting the wires 21, 21 together. If snow adheres to such electric wires with a circular cross section, the snow will rotate and grow, causing the wires to break or stretching due to increased weight, which could adversely affect the internal optical fibers. .

Therefore, the applicants previously proposed a snow-resistant optical fiber overhead electric wire W as shown in FIGS. 6 and 7, which can prevent the snow from accumulating (Utility Application No. 114,694/1982).
As shown in the figure, the unit strand is 10 or 1
0' is compound twisted, and each unit strand is twisted so that the center of the wire is at the vertex of a triangle, and the unit wire 10 has an aluminum pipe 12 Arranged, this aluminum pipe 12
Tension member 15, cushion material 16 inside
Also, the optical fiber 14 is housed and held down by a pressing tape 17, and the other unit stranded wire 1 is
0' is a normal twisted wire structure. Such a composite overhead electric wire W can constitute a necessary communication line by increasing or decreasing the number of unit stranded wires 10 containing optical fibers as necessary. However, since the overhead wires constructed in this manner do not have a circular cross section as in the case shown in FIG. They fall one after another.

By the way, the anti-snow electric wire with the above structure has a special cross-sectional structure in addition to being effective in preventing snow from accreting, so a special spacer is inserted in the wire gripping part of the overhead wire so that the entire cross-section is circular. It was necessary to use a special overhead wire method, such as using a special overhead wire method, which could result in abnormal compressive force being applied to the wires, which could cause unintended strain on the internal optical fibers.

[Problems to be Solved by the Invention] As already explained, an electric wire made of composite stranded wire is a set of a plurality of unit stranded wires, and when an optical fiber is housed in it, the line capacity as a communication line is reduced. For example, it is not necessary to accommodate optical fibers in all unit strands, but it is sufficient to accommodate only some of the unit strands. Furthermore, it does not mean that all the unit stranded wires must share the tension of the overhead wires equally when they are tied to the steel tower, but rather that the tension caused by the design slack should be shared by some of the unit stranded wires. is quite possible.
In this case, when connecting electric wires having the configuration shown in FIGS. 6 and 7, by appropriately utilizing the special configuration itself without intervening the special spacer, etc., If it were possible to construct an overhead line without the risk of applying excessive tension to the optical fiber, the problems caused by the special configuration described above would be solved at once.

[Means for solving the problems] The present invention was developed based on the above knowledge, and
This was achieved as a result of various experiments, and its gist is that it consists of a composite stranded wire made by further twisting a plurality of unit stranded wires, at least one of the unit stranded wires contains an optical fiber, At least one of the above is a method for overhead wiring of an optical fiber composite overhead electric wire having a structure that does not include an optical fiber, wherein the electric wire is supported on a steel tower by a unit stranded wire that does not include an optical fiber, and a unit stranded wire that includes an optical fiber. This invention relates to a method of overhead wiring of optical fiber composite overhead electric wires in which the optical fibers are suspended in a non-tensioned state.

[Example] This will be explained below based on examples.

As an electric wire to which the present invention is applied, in order to simplify the explanation, a case will be described in which an electric wire having a cross-sectional structure shown in FIG. 7 is used as an overhead wire.

The electric wire shown in FIG. 7 is constructed as an overhead ground wire, and the aluminum-covered steel wire 11 is made by coating the outer periphery of a steel wire 11a with aluminum 11b.
are using. Two unit stranded wires 10' made by twisting aluminum-coated steel wires 11 together, and a unit stranded wire 10 with built-in optical fibers made by twisting the bare wires 11 around the outer periphery of the pipe 12 containing the already explained optical fiber 14. As shown in the figure, the whole is constructed in a triangular cross-section by compound twisting. The aluminum-coated steel wire, which serves as the wire that makes up each stranded wire, has a very high strength, and even one unit stranded wire can sufficiently maintain the overhead wire tension of the overhead ground wire W. be.
FIG. 1 is an explanatory diagram showing a state in which the above-mentioned optical fiber overhead electric wire W is wired by the overhead wire method according to the present invention. The retaining clamp 2 that holds the electric wire W to the steel tower 1 compresses and grips only the unit stranded wire 10' that does not contain the optical fiber of the electric wire W, and the unit stranded wire 10 that contains the optical fiber is untwisted into a loop shape as shown in the figure. and is supported in a tension-free state. Reference numeral 3 denotes a stopper for fixing the branched parts obtained by untwisting the unit stranded wire, and its details are shown in FIG. 2, which is an enlarged view of section C in FIG. 1. 3 is a sectional view taken along line BB in FIG. 1, and FIG. 4 is a sectional view taken along line AA in FIG. 1.

In the above-mentioned embodiment, a structure having three unit stranded wires and one unit stranded wire with built-in optical fiber was exemplified, but it goes without saying that the structure is not limited to such a structure. The number of unit stranded wires may be as large as possible, and there is no problem in having a plurality of unit stranded wires built into the optical fiber. The structure of the strands is not limited to the aluminum-coated steel wire described above, but may also be a galvanized steel wire. Further, the electric wire is not limited to an overhead ground wire, and of course may be a compound twisted ordinary steel-core aluminum stranded wire. Furthermore, the method of storing the optical fiber is not limited to the above embodiment, and there are various ways of storing the optical fiber, such as simply storing it loosely in a pipe, and the selection and application of the present invention are There is no particular relationship between them.

[Effect of the invention] As described above, according to the overhead line method according to the present invention,
The tethering or suspension to the steel tower is carried out by unit stranded wires that do not contain optical fibers, and the unit stranded wires that contain optical fibers are maintained without tension, so that the tension of the overhead wires is not directly or indirectly applied to the optical fibers. Since the optical fiber can be wired without reaching the target, there is no risk of abnormal distortion being applied to the optical fiber.Furthermore, if the optical fiber is wired without tension and with extra length as in the present invention, the sensor It is easy to make branch connections to the tower itself, and even if it becomes necessary to monitor the tower itself by installing a separate sensor on the tower, there are secondary benefits such as the ability to easily utilize the optical fiber that is already installed. Its industrial significance should be highly evaluated as it is timely as the practical application of optical fiber composite overhead wires is gaining momentum.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing the state in which the overhead wire method according to the present invention is implemented, FIG. 2 is a detailed diagram of section C in FIG. 1,
Figure 3 is a cross-sectional view taken along line B-B in Figure 1, Figure 4 is a cross-sectional view taken along line A-A in Figure 1, Figure 5 is a cross-sectional view showing the structure of a conventional optical fiber overhead wire, and Figure 6 is a cross-sectional view taken along line A-A in Figure 1. FIG. 7 is a perspective view showing an example of an optical fiber overhead wire to which the invention is applied, and FIG. 7 is a sectional view showing another embodiment of the electric wire to which the invention is applied. 1: Steel tower, 2: Detention clamp, 10: Unit stranded wire including optical fiber, 10': Unit stranded wire not including optical fiber, 14, 24: Optical fiber, W: Optical fiber composite overhead wire.

Claims (1)

[Scope of Claims] 1. An optical fiber consisting of a composite stranded wire formed by further twisting a plurality of unit stranded wires, at least one of the unit stranded wires containing an optical fiber, and at least one of the unit strands containing no optical fiber. An optical fiber composite overhead wire is an overhead wiring method for a composite overhead electric wire, in which the electric wire is supported on a steel tower using a unit stranded wire that does not contain an optical fiber, and the unit stranded wire that contains an optical fiber is suspended in a non-tensioned state. overhead line method. 2. The optical fiber composite overhead electric wire to be connected is composed of three unit stranded wires, which are twisted together so that the center of each stranded wire is at the vertex position of a triangle. overhead line method.