JPH07235225A - Optical fiber-compounded overhead earth wire - Google Patents

Abstract

PURPOSE:To provide an optical fiber-compounded overhead earth wire with excellent corrosion resistance by using an aluminum alloy containing a prescribed amount of manganese and the balance of aluminum and impurities for a material of an aluminum pipe. CONSTITUTION:An optical fiber compounded overhead earth wire is composed of an aluminum pipe 1, an optical fiber 2 inserted into the aluminum pipe 1, and stranded wires 3 put in the outer circumference of the aluminum pipe 1. The standed wires 3 consist of a plurality of wires 4 such as aluminum alloy wires, aluminum-coated steel wires and are stranded on the outer circumference of the aluminum pipe 1. The optical fiber 2 is composed of, for example, a plurality of optical fiber core wires and a sheath coating the core wires. The aluminum pipe 1 is made of an aluminum alloy containing 0.2-2.0wt.% of manganese and the balance of aluminum and impurities. In the case that the content of the manganese is set to be 0.9-1.6wt.% the pipe may exhibit specially high corrosion resistance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber composite overhead ground wire.

[0002]

2. Description of the Related Art Aluminum pipes (for housing and protecting optical fibers) of an optical fiber composite overhead ground wire are generally manufactured by welding pure aluminum or an alloy tape containing a trace amount of copper to aluminum. is doing.

[0003]

However, the optical fiber composite overhead ground wire is generally supported between support materials such as a steel tower, and when wired in a coastal area or an industrial area, an aluminum pipe is used. Could be corroded. Also,
When the aluminum tube corrodes, the strength of the aluminum tube is remarkably lowered, and the aluminum tube may be broken due to fatigue, or the airtightness may be deteriorated and water or a corrosion product may enter to deteriorate the optical fiber.

Therefore, conventionally, it has been considered to apply grease to the aluminum tube or to coat the aluminum tube with plastic, but there is a drawback that the workability is poor and the cost is high.

Therefore, an object of the present invention is to provide an optical fiber composite overhead ground wire having excellent corrosion resistance.

[0006]

In order to achieve the above object, a first optical fiber composite overhead ground wire according to the present invention comprises:
In an optical fiber composite overhead ground wire comprising an aluminum tube through which an optical fiber is inserted and a twisted wire arranged on the outer periphery of the aluminum tube, the material of the aluminum tube is 0.2 to 2.0 manganese. It is an aluminum alloy containing 50% by weight and the balance being aluminum and impurities.

A second optical fiber composite overhead ground wire according to the present invention is an optical fiber having an aluminum tube through which the optical fiber is inserted and a twisted wire arranged on the outer circumference of the aluminum tube. In the composite overhead ground wire, the material of the aluminum pipe is an aluminum alloy containing 0.9 to 1.6% by weight of manganese and the balance being aluminum and impurities.

A third optical fiber composite overhead ground wire according to the present invention is an optical fiber provided with an aluminum tube through which the optical fiber is inserted and a twisted wire arranged on the outer periphery of the aluminum tube. In a composite overhead wire, the aluminum pipe material is an aluminum alloy containing 0.2 to 2.0% by weight of manganese and either 0.03 to 0.3% by weight of copper or 0.1 to 2.0% by weight of magnesium. It is what

A fourth optical fiber composite overhead ground wire according to the present invention is an optical fiber provided with an aluminum tube through which the optical fiber is inserted and a twisted wire arranged on the outer periphery of the aluminum tube. In composite overhead ground wire, the aluminum pipe material is an aluminum alloy containing 0.9 to 1.6% by weight of manganese and either 0.03 to 0.3% by weight of copper or 0.1 to 2.0% by weight of magnesium. It is what

[0010]

The aluminum tube contains 0.2 to 2.0% by weight of manganese, and therefore has excellent corrosion resistance. In particular, when the manganese content is 0.9 to 1.6% by weight, the corrosion resistance becomes very good.

Further, in the case of containing copper in an amount of 0.03 to 0.3% by weight, even if corrosion occurs, the corrosion does not proceed so much in the thickness direction, resulting in a shallow corrosion on the whole surface.

Further, 0.1 to 2.0% by weight of magnesium
With the inclusion, the pitting corrosion resistance is further improved and the corrosion resistance is further improved.

[0013]

The present invention will be described in detail below with reference to the drawings illustrating the embodiments.

FIG. 1 shows an optical fiber composite overhead ground wire according to the present invention. This optical fiber composite overhead ground wire includes an aluminum tube 1, an optical fiber 2 inserted through the aluminum tube 1, and an aluminum tube 1. And a twisted wire 3 disposed on the outer circumference.

The twisted wire 3 is formed by twisting a plurality of wires (7 in the illustrated example) such as aluminum wire, aluminum alloy wire, and aluminum-coated steel wire 4 on the outer circumference of the aluminum tube 1 in one or more layers. Formed by. In the illustrated example, the wire 4 is an aluminum-coated steel wire.
That is, the wire 4 includes a steel wire 5 having a circular cross section and an aluminum coating layer 6 that covers the steel wire 5.

The optical fiber 2 is composed of, for example, a plurality of optical fiber core wires and a sheath that covers the optical fiber core wires.

Thus, the aluminum tube 1 is made of an aluminum alloy containing 0.2 to 2.0% by weight of manganese and the balance being aluminum and impurities.

That is, by containing manganese,
The corrosion resistance of this aluminum tube 1 is improved. By the way, if the content of manganese is less than 0.2%, the content is too low to improve the corrosion resistance, and if it is higher than 2.0%, the conductivity becomes poor. In addition, the manganese content should be 0.9 to 1.6.
If it is set to about%, it will show particularly excellent corrosion resistance. Here, the impurities are silicon, iron, chromium, zinc,
Titanium, etc., in which case silicon is 0.6 to 0.3% or less, iron is 0.7% or less, chromium is 0.1% or less, and zinc is 0.25 or less.
To 0.1% or less is preferable. Further, other unavoidable impurities are preferably 0.15% or less.

The aluminum alloy contains 0.2 to 2.0% by weight of manganese and 0.03 to 0.3% by weight of copper.
It may be contained.

That is, the inclusion of copper improves pitting corrosion resistance, and mitigates that corrosion progresses in the thickness direction and concentrates at one point. Therefore, the entire surface is corroded, and the durability is excellent with respect to the corrosion in the plate thickness direction. By the way, if the copper content is less than 0.03%, this effect cannot be expected, and if the copper content is higher than 0.3%, the conductivity decreases and the workability deteriorates, and the general corrosion is remarkable. However, there is a drawback that the corrosion resistance decreases.

Further, as this aluminum alloy,
0.2 to 2.0% by weight of manganese and magnesium
It may contain 0.1 to 2.0% by weight.

That is, by containing magnesium, the pitting corrosion resistance is improved, and by promoting the formation of an oxide film, the corrosion resistance is further improved. By the way, if the content of magnesium is less than 0.1%, it is not possible to expect the improvement of the corrosion resistance due to this magnesium, and if the content of magnesium is higher than 2.0%, the conductivity is lowered and the workability is deteriorated. is there.

Whether copper is contained or magnesium is contained, the manganese content is 0.9 to
It is preferably set to 1.6% by weight.

Next, FIG. 2 shows another embodiment. In this case, the wire 4 of the twisted wire 3 has a substantially trapezoidal cross section, whereas the wire 4 of the above embodiment has a circular cross section. . That is, the wire 4 includes a steel wire 7 having a substantially trapezoidal cross section and an aluminum coating layer 8 that covers the steel wire 7.

However, also in this case, the aluminum tube 1 through which the optical fiber 2 is inserted is made of the same aluminum alloy as that of the embodiment shown in FIG. Therefore, also in this case, excellent corrosion resistance is exhibited.

When the optical fiber 2 is inserted into the aluminum tube 1, it is directly inserted into the aluminum tube 1 as shown in FIGS. 1 and 2, but the spacer 9 is inserted into the aluminum tube 1 as shown in FIG. Through the groove of the spacer 9
The optical fiber 2 may be inserted (played loosely) into the optical fiber 10.

That is, the spacer 9 is made of an aluminum alloy in which a plurality of longitudinal grooves 10 (the grooves 10 are twisted along the longitudinal direction) are formed on the outer peripheral surface 9a.
The aluminum alloy may be the above-mentioned alloy used for the aluminum tube 1 or another aluminum alloy. Further, the number of the recessed grooves 10 can be freely increased or decreased, and the shape of the recessed grooves 10 is not limited to the semi-elliptical shape, but may be a semi-elliptical shape, a rectangular or square shape, a triangular shape, a trapezoidal shape or the like.

By the way, the number of the wire rods 4 of the twisted wire 3 is 7 in FIG. 1 and 6 in FIG. 2, but of course, the number is not limited to these numbers, and the number may increase or decrease. It is free and the number of layers to be twisted is also free.

The aluminum pipe 1 generally has an outer diameter of about 5 to 6.5 mm and a wall thickness of about 0.5 mm, but of course, the invention is not limited to this.
It may be a welded pipe or an extruded pipe.

Next, an experimental example is shown.

[0031]

[Table 1]

First, five aluminum tubes 1 having the components shown in Experimental Examples (1) to (5) of Table 1 are prepared. Each aluminum tube 1 is a welded tube (containing aluminum alloy spacer 9 and optical fiber 2) having a diameter of 5 mm and a wall thickness of 0.5 mm.
(TIG) Created by welding and roll forming. Then, eight aluminum-coated steel wires having a diameter of 3.2 mm and an aluminum layer thickness of 0.26 mm are twisted together in the aluminum tube 1 to form an optical fiber composite overhead ground wire.

Next, a salt spray test based on JIS Z 2371 was carried out for 5000 hours on these optical fiber composite overhead ground wires of (1) to (5), and the corrosion occurrence state on the surface of the aluminum tube 1 was examined. Is shown in Table 1.

Further, (6) to (11) in Table 1 show comparative examples,
These aluminum tubes were used as the components shown in Table 1. Also in the case of this comparative example, an optical fiber composite overhead ground wire was prepared by the same method as the optical fiber composite overhead ground wire of (1) to (5).

Then, the optical fiber composite overhead ground wire of (6) to (11) is also subjected to the same salt spray test as the above optical fiber composite overhead ground wire of (1) to (5), and the aluminum pipe surface is tested. The state of corrosion occurrence was examined and the results are shown in Table 1.

The conductivity before the salt spray test and the easiness of roll forming (moldability) at the time of forming a welded pipe were also investigated, and the results are shown in Table 1.

Thus, it can be seen that the optical fiber composite overhead ground wire according to the present invention is excellent in corrosion resistance.

[0038]

Since the present invention is configured as described above, it has the following effects.

According to the optical fiber composite overhead ground wire according to the first and second aspects, the aluminum tube has excellent corrosion resistance, and excellent corrosion resistance can be obtained even as the optical fiber composite overhead ground wire. The reliability as a fiber composite overhead ground wire is improved. Particularly, according to the optical fiber composite overhead ground wire of the second aspect, more excellent corrosion resistance can be obtained.

According to the optical fiber composite overhead ground wire of the third and fourth aspects, it is possible to obtain the same excellent corrosion resistance as the optical fiber composite overhead ground wire of the first or second aspect. Further, in the case of containing 0.03 to 0.3% by weight of copper, even if corrosion occurs in the aluminum tube 1, the corrosion does not proceed in the thickness direction and concentrate at one point. That is, the corrosion is complete and the durability is excellent. And, in the case of containing 0.1 to 2.0% by weight of magnesium, the corrosion resistance due to this magnesium is improved,
The optical fiber composite overhead ground wire as a whole exhibits extremely excellent corrosion resistance. Particularly, according to the optical fiber composite overhead ground wire of the fourth aspect, the corrosion resistance due to manganese is further improved.

According to each optical fiber composite overhead ground wire,
Applying the anti-corrosion grease that was previously required,
It is not necessary to separately provide an anticorrosion layer, so that productivity is not reduced and workability is not deteriorated.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing another embodiment.

FIG. 3 is a cross-sectional view of main parts of another embodiment.

[Explanation of symbols]

 1 Aluminum tube 2 Optical fiber 3 Stranded wire

Claims (4)

[Claims] 1. An optical fiber composite overhead ground wire comprising an aluminum tube through which an optical fiber is inserted, and a twisted wire arranged on the outer circumference of the aluminum tube, wherein the material of the aluminum tube is: An optical fiber composite overhead ground wire comprising 0.2 to 2.0% by weight of manganese, the balance being aluminum and an aluminum alloy containing impurities. 2. An optical fiber composite overhead ground wire comprising an aluminum tube through which an optical fiber is inserted and a twisted wire arranged on the outer periphery of the aluminum tube, wherein the material of the aluminum tube is: An optical fiber composite overhead ground wire comprising 0.9 to 1.6% by weight of manganese and the balance being aluminum and an aluminum alloy containing impurities. 3. An optical fiber composite overhead ground wire comprising an aluminum tube through which an optical fiber is inserted, and a twisted wire arranged on the outer periphery of the aluminum tube, wherein the material of the aluminum tube is: An optical fiber composite overhead ground wire, which is an aluminum alloy containing 0.2 to 2.0% by weight of manganese and either 0.03 to 0.3% by weight of copper or 0.1 to 2.0% by weight of magnesium. 4. An optical fiber composite overhead ground wire comprising an aluminum tube through which an optical fiber is inserted and a twisted wire arranged on the outer periphery of the aluminum tube, wherein the material of the aluminum tube is: An optical fiber composite overhead ground wire comprising an aluminum alloy containing 0.9 to 1.6% by weight of manganese and either 0.03 to 0.3% by weight of copper or 0.1 to 2.0% by weight of magnesium.