JP3185349B2 - Overhead transmission line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an overhead transmission line excellent in bending fatigue strength and plastic deformation during twisting.

[0002]

2. Description of the Related Art Conventional overhead transmission lines include the following.

As a first conventional example, as shown in FIG. 2, an overhead transmission line is formed by twisting an aluminum wire 2 reinforced with short fibers around an outer periphery of a Zn-plated steel core 1. Short fibers are used in the aluminum wire 2 so as not to change the conductivity of aluminum. By using this aluminum wire 2 as a kind of high-strength aluminum, the Zn-plated steel core 1 is made thinner than a conventional transmission line, thereby reducing the weight.
An example of this is a steel core aluminum stranded wire described in JP-A-2-181303.

As a second conventional example, as shown in an enlarged cross-sectional view in FIG. 3, aluminum or aluminum alloy 5 is used as a matrix, and silicon carbide fibers 6 are compounded and integrated to form a composite wire 7. In some cases, the composite wire 7 is configured as an overhead transmission line as part or all of a conductor. The outer periphery of the composite wire 7 is covered with an aluminum tape or an aluminum pipe 8. According to an overhead power transmission line using such a composite wire as a part or the whole of a conductor, an overhead power transmission line which does not require a steel core, can significantly reduce weight, reduce a coefficient of linear expansion, and is excellent in heat resistance. As a result, it is possible to significantly increase the capacity and to reduce the tower height and the tower strength, thereby making it possible to construct an economical railway line. An example of this is disclosed in, for example, JP-A-3-715.
There is an overhead transmission line described in Japanese Patent Application Laid-Open No. 09-0909.

[0005]

However, the above-mentioned prior art has the following problems.

(1) The first conventional overhead transmission line is AC
Although it is a kind of SR, the Zn-plated steel core 1 is made thinner to reduce the weight. However, since the steel core 1 itself is used without being omitted, there is a limit in reducing the weight.
Also, the coefficient of linear expansion of the overhead transmission line depends on the steel core,
In addition, since the linear expansion coefficient of the conventional example is large, it is difficult to increase the capacity in terms of strength.

(2) In the second conventional example, the above problem has been solved. However, in the case of a composite wire 7 in which aluminum or an aluminum alloy 5 is combined with a uniform long silicon carbide fiber 6, a stranded wire is formed. Poor in formability, this stranded wire formability and instability in overhead wire construction
In order to solve the problem, it was necessary to cover the outer periphery of the composite wire 7 with an aluminum tape or an aluminum pipe 8. further,
Although excellent in the properties in the longitudinal direction, for example, uniaxial tension, there is a possibility of breaking due to bending fatigue and the like. That is, the material of the composite wire 7 has anisotropy (uniaxial orientation), and it is necessary to improve this to an isotropic (multidimensional orientation) material.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an overhead transmission line which is easy to reduce the weight and increase the capacity, and is excellent in bending fatigue strength and plastic deformation at the time of twisting. To provide.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides an overhead transmission line comprising a composite wire formed by combining aluminum or an aluminum alloy and a fiber as part or all of a conductor. And a length corresponding to at least one span between the composite wire and the aluminum or aluminum alloy provided at the center.
, And a long fiber composite layer obtained by compounding the long fiber, and an outermost layer of aluminum or aluminum alloy alone provided on the outer periphery of the long fiber composite layer.

[0010] In the above overhead transmission line, aluminum or an aluminum alloy is interposed between the long fiber composite layer and the outermost layer.
May be provided with a short fiber composite layer obtained by compounding with the short fiber having a length equal to or less than the thickness of the fiber.

[0011]

Further, the cross-sectional shape of the outermost layer is formed into a predetermined shape by drawing.

[0013]

According to the above construction, the uniaxial tensile strength is improved by the long fiber composite layer, the occurrence of cracks can be suppressed by the short fiber, and the weight and capacity can be increased without deteriorating the tensile strength of the transmission line. It will be easier. Further, the bending fatigue strength is also improved.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of an overhead transmission line according to the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 (A) and 1 (B) are enlarged cross-sectional views showing one of the composite lines constituting an overhead transmission line according to the present invention, and FIG. It is a longitudinal cross-sectional view. The composite wire 11 is configured as follows as a composite wire obtained by combining aluminum or an aluminum alloy (hereinafter, referred to as “aluminum 12”) and a fiber 13.

At the center of the composite wire 11, a long fiber composite layer 1 composed of aluminum 12 and a long fiber 13A is formed.
4 are provided. On the outer periphery of the long fiber composite layer 14, a short fiber composite layer 16 in which aluminum 12 and short fibers 13B are composited is provided. Further, on the outer periphery of the short fiber composite layer 16, an outermost layer 17 of aluminum 12 alone, which does not composite fibers, is provided. The above three layers 14, 1
The composite line 11 is composed of 6, 17. Each fiber 1
Silicon carbide, carbon fiber, or the like is used as 3A and 13B.

As the long fiber 13A, a fiber having a length corresponding to at least one span is used. The short fibers 13B, the fibers of the thickness t ₁ following the length of the short fiber composite layer 16 is used. Note that the thickness t ₂ of the outermost layer 17 must be at least 10% of the outer diameter is confirmed practical as the limit of the processing. The thickness t ₁ is the thickness of the short fiber composite layer 16, and the thickness t ₂ is the thickness of the outermost layer 17.

In the case where the fibers are used to reinforce the electric wire in one axial direction, the fibers need to be long. For example, when short fibers 13B having a diameter of 15 μm and a length of 50 μm are used as reinforcing fibers, 16 to 20 as shown in FIG.
It is about Kgf / mm ² . On the other hand, when using the long fiber 13A having a fiber diameter of 15 μm and a length corresponding to one span (a fiber having the same length as the length of the tensile test piece), 45 to 50 kgf / mm ² or more. The volumetric composite ratio Vf of the fibers was set to 15%.

In order to use the composite wire as a strand for an overhead power transmission line, it is necessary to have a strength sufficient to support the tension when the wire is installed. Therefore, the long fiber 13A needs to be a fiber having a length corresponding to at least one span.

It is necessary that the short fibers 13B are mixed so that the power transmission rate of the aluminum 12 is not changed so much, and that the short fibers 13B are long enough to prevent crack propagation.
Further, the fiber length must not be so long that the end of the short fiber 13B reaches the outermost layer 17 beyond the short fiber composite layer 16. The length satisfying these conditions must be at least not more than the thickness t ₁ of the short fiber composite layer 16.
The diameter of the short fiber 13B is set to about 0.2 to 0.5 μm.

The production of the composite wire 11 having the above configuration uses the following processing means. When a composite wire is manufactured by a dipping method using silicon carbide / aluminum as a seed wire, the aluminum has a cast structure and the surface is slightly porous. This state is not so preferable as a strand for an overhead transmission line, and a drawing process using a roller die or the like is performed to improve strength and form.

The overhead transmission line using the composite wire constructed as described above as a part or the whole of the stranded conductor can be easily reduced in weight and capacity without deteriorating its original functions such as tensile strength of the overhead transmission line. And the bending fatigue strength is also improved.

Further, by arranging the long fiber composite layer 14 using the long fibers 13A at the center, plastic deformation such as a twisted wire becomes possible, and a more practical element wire can be supplied.

In the above embodiment, the case where the short fiber composite layer 16 is provided on the outer periphery of the long fiber composite layer 14 as the composite wire 11 has been described as an example. The composite wire 11 comprises only the fiber composite layer 14 and the outermost layer 17.
May be configured. In this case, the same operation and effect as described above can be obtained. In addition, the fibers do not diffuse into the cross section,
By arranging the long fiber composite layer 14 at the center, it is possible to perform a preform (plastic working to prevent looseness) on the stranded wire. The overhead transmission line may be a single line using one composite line 11 or a stranded line using a plurality of composite lines.
In the case of a stranded wire, a metal wire such as an aluminum wire other than the composite wire 11, an aluminum alloy wire, a Zn-plated steel wire, or a composite wire may be included.

The short fibers 13B may be whiskers.

[0026]

As described in detail above, according to the overhead transmission line of the present invention, the uniaxial tensile strength is improved by the long fiber composite layer, and the occurrence of cracks in the short fibers can be suppressed. As a result, the transmission line can be easily reduced in weight and capacity without impairing the functions of the overhead transmission line, such as electrical characteristics, coefficient of linear expansion, and tensile strength. Furthermore, the bending fatigue strength and the retrograde deformability at the time of twisting are also improved.

[Brief description of the drawings]

FIG. 1 is an enlarged transverse sectional view and an enlarged longitudinal sectional view showing a composite line constituting an overhead transmission line according to the present invention.

FIG. 2 is a cross-sectional view showing an overhead power transmission line as a first conventional example.

FIG. 3 is an enlarged cross-sectional view showing a composite line constituting an overhead transmission line as a second conventional example.

FIG. 4 is a table showing test results of tensile strength.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Composite wire 12 Aluminum 13 Silicon carbide fiber 13A Long fiber 13B Short fiber 14 Long fiber composite layer 16 Short fiber composite layer 17 Outermost layer

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-71509 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01B 5/08 H01B 5/02

Claims (3)

(57) [Claims] 1. An overhead power transmission line comprising a composite wire made of aluminum or an aluminum alloy and a fiber as a part or all of a conductor, wherein the composite wire is provided at a central portion and is made of aluminum or aluminum alloy. And at least one span
Overhead power lines and long fiber composite layer that combines with the fibers of the long, characterized in that it is composed of the outermost layer of aluminum or aluminum alloy alone provided on the outer periphery of the elongated fiber composite layer . 2. An overhead transmission line comprising a composite wire made of aluminum or an aluminum alloy and a fiber as a part or the whole of a conductor, wherein the composite wire is provided at a center portion of the aluminum or aluminum alloy. And at least one span
A long fiber composite layer obtained by compounding the long fiber, and a composite of aluminum or an aluminum alloy provided on the outer periphery of the long fiber composite layer and the short fiber having a length equal to or less than the thickness of the layer. An overhead transmission line comprising: a short fiber composite layer formed as described above; and an outermost layer of aluminum or an aluminum alloy alone provided on an outer periphery of the short fiber composite layer. 3. A cross-sectional shape of the outermost layer is formed by drawing.
The overhead power transmission according to claim 1 or 2, wherein the overhead transmission is formed into a predetermined shape.
line.