JPH09161541A - Low wind pressure electric wire with low degree of slackness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost overhead cable with the wind pressure load and the degree of slackness reduced. SOLUTION: An Invar steel strand or the like having a small coefficient of linear expansion is used as tension sharing core wires 5 of an overhead cable, and a groove 3 having a circular arc section is provided at the front surface of adjacent parts 2 of segment element wires 1 consisting of super-heat resisting or special heat resistant aluminum alloy to be twined together on the outermost layer, and a spiral groove having a circular arc section is formed on the outside surface of the overhead cable, and thereby increase in the degree of slackness at the time of high temp. is suppressed, and the exfoliating point is moved to wind downstream on the surface of the overhead cable when wind runs against it and the boundary layer of air stream flowing on the surface passes the groove 3. Thereby the wind pressure load is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low slack low wind piezo electric wire which has a small wire sag at high temperatures and a small wind pressure resistance under strong wind.

[0002]

2. Description of the Related Art Electric wires used for overhead electric wires are currently ACSR.
(Stand core aluminum stranded wire) is the mainstream, and in order to increase capacity and decrease sag, heat resistance has been improved or low linear expansion steel wire such as Invar steel wire has been adopted, and many materials and machinery have been adopted. The characteristics are being improved and developed. Recently, instead of Invar steel wire, Sic (silicon carbide) fiber reinforced aluminum composite wire, FRP wire in which carbon fiber or aramid fiber is impregnated with resin, or other inorganic or organic fiber is plated with aluminum or zinc. Research and development has also been conducted to reduce the linear expansion and weight reduction of the ACSR steel core by twisting together the strands made into wire rods, and suppressing the wire elongation at high temperatures to achieve low sag.

[Problems of Prior Art] As described above, an electric wire having a low degree of sag is advantageous in that it can suppress an increase in sag due to the elongation of the electric wire at a high temperature, so that the tower height of a steel tower or the like can be lowered. However, the increase in wind pressure load during strong winds is equivalent to that of the conventional ACSR, and especially in ultra-high-voltage multi-conductor and multi-line transmission lines, the wind pressure load of electric wires is the dominant factor in the strength design of steel towers. The economic merit is not enough just to control the sag.

As shown in FIG. 17, an aluminum stranded wire 6 on a steel stranded wire 5 is used as an aluminum stranded wire having a substantially smooth outer peripheral surface.
There is known an electric wire in which a segment wire 15 having a fan-shaped cross section is twisted on the outermost layer of the outer circumference of the wire, and a V-shaped groove 17 is formed on the surface side of the adjacent portion 16 of each twisted segment wire 15, 15. . This electric wire has a step in the V-shaped groove 17 formed on the surface side of the adjacent segment 16 of the twisted segment wires 15 having a fan-shaped cross section in the outermost layer, and therefore, when the wind hits, the V-shaped groove is formed. It was found that 18 steps disturb the boundary layer and the wind load increases. However, it is not easy to create a smooth surface by eliminating the steps of the V-shaped groove 17 adjacent to the twisted segment wire, and the manufacturing cost becomes high.

The inventors of the present invention have found that in the process of developing a low wind piezoelectric wire, if a special spiral groove is provided on the surface of the power transmission line,
It was found that the wind pressure resistance decreases under strong winds of 0 to 40 m / s or more, and accordingly, overhead wires are combined with multiple segment fan-shaped segment wires in the outermost layer, and each segment wire is adjacent. It is possible to reduce the wind pressure of the electric wire by providing a groove portion having an arcuate cross section on the surface side of the portion, and further, the groove width L of the groove portion having the arcuate cross section and the width M of the non-groove portion of the segment wire surface having the sectoral cross section. The ratio L / M to 0.10 ≦
L / M ≦ 1.55, and the ratio H / D between the maximum depth H of the circular-arc groove section and the overhead wire diameter D is 0.0055 ≦ H /
Japanese Patent Application No. Hei. 7- which enables low wind pressure by setting D ≦ 0.082 and the number of twisted strands of the sector-shaped segmental wire of the outermost layer being 6 or more and 36 or less. The electric wire of 113687 was developed.

As described above, the low-wind piezoelectric wire can reduce the wind pressure, but cannot avoid an increase in the sag due to the wire extension at high temperature. For example, when the span length is in the 1000 to 3000 m class, the sag becomes several tens of meters or more, and when a ship or the like crosses, the maximum sag is limited. Therefore, even for wires with low wind pressure, the increase in slackness at high temperature requires a high strength wire depending on the wire conditions, and it is necessary to erect with a significantly high tension at all times, which is a disadvantage for the tower design. Is. In addition, when installed with high tension, the surface of low-wind piezoelectric wire is almost smooth, so slight wind vibration is likely to occur, and there is a higher concern of wire fatigue due to vibration, and installation of large-scale anti-vibration devices and daily maintenance inspections are performed. Will cost a lot of money.

[0007]

The demand for electric power is expected to grow in the future, and particularly in Japan, there are many routes that pass not only in mountainous areas but also in urban areas, and development of compact and high-density transmission technology is desired. To do this, (1) reduce the increase in wind pressure load on the wires even under high wind speeds such as during typhoons, and (2) suppress the increase in sag even at high temperatures when the wires rise in temperature. It is desirable to make the design etc. compact and economical. However, conventional A
A CSR, a sag control type electric wire, a low wind piezoelectric wire, or the like has only a single function of low sag or a low wind pressure, and does not have a combined function of low sag and low wind pressure. There wasn't.

The present invention solves the above-mentioned problems and can suppress an increase in slack due to the elongation of an electric wire at a high temperature, and
An object of the present invention is to provide a low-cost low-sagility low-wind piezoelectric wire that can reduce an increase in wind pressure load on an electric wire even under high wind speed.

[0009]

In order to achieve the above object, the low sag / low wind piezoelectric wire of the present invention is characterized by the following constitutions (1) to (9). The "electric wire" of the low wind piezoelectric wire includes not only a power transmission line but also an overhead ground wire.

(1) The tension-sharing core material 5 having a linear center has a linear expansion coefficient of ^{−6 to 6} × 10 ⁻⁶ / ° C. and an elastic coefficient of 100 to 600 GPa and a low linear expansion coefficient and high elasticity. Wires with a coefficient are used, and the outermost layer of the stranded wire is composed of a plurality of fan-shaped segment wire segments 1 made of a super heat-resistant aluminum alloy or a special heat-resistant aluminum alloy. A groove portion 3 having an arcuate cross section is provided on the front surface side of 2.

(2) In the low slack low wind piezoelectric wire of the above (1), the tension-sharing core material 5 includes an invar wire or an inorganic fiber such as silicon carbide fiber, carbon fiber or alumina fiber, or an organic fiber such as aramid fiber. A preformed wire of this composite wire is more characterized by using a composite wire that is plated or coated with a metal selected from the group consisting of aluminum, zinc, chrome, copper, etc. on the surface of a thin filament made of fiber. Used together.

(3) Further, in the low sag and low wind piezoelectric wire of (1) or (2), the groove width L of the groove portion 3 having an arcuate cross section and the width M of the non-groove portion of the segment wire surface having a fan-shaped cross section. Ratio L
/ M is 0.10 ≦ L / M ≦ 1.55.

(4) Further, in the low sag / low wind piezoelectric wire of (1), (2) or (3), the groove portion 3 having an arcuate cross section is used.
The ratio H / D between the maximum depth H and the overhead wire diameter D is 0.005
It is characterized in that 5 ≦ H / D ≦ 0.082.

(5) Further, the above (1), (2) and (3)
Alternatively, in the low-sagility low-wind piezoelectric wire of (4), at least one, and preferably two segment wires 11 of a plurality of sector-shaped segment wires 1 having a cross-section that are fitted to each other by the outermost layer,
The outer surface 7 is an outer surface protruding segment wire 11 having a protruding step t protruding higher than the outer surface 4 of another segment wire 1.

(6) In the low sag / low wind piezoelectric wire of (5), the protrusion step t of the outer surface protruding segment wire 11 is 0.5 to 5.0 mm, preferably 0.5 to 2.0 m.
It is characterized in that it is m.

(7) Further, in the low sag / low wind piezoelectric wire of (5) or (6), the outer surface protruding segment element wire 1 is used.
15 ° ≦ θ ≦ 6 on the shoulder 12 having the protruding step t of 1
It is characterized in that a deflector angle θ of 0 ° is provided. (See Figures 2 and 3)

(8) Further, in the low sag and low wind piezoelectric wire of the above (1) to (6), the groove portion on the front surface side of the sectoral segment wire adjacent portion 2 of the outermost layer is formed in the semicircular groove portion 3a in cross section. Then, the wire 14 having a circular cross-section is fitted and twisted into at least one semi-circular groove 3a of the cross-section of the outermost layer, and the outermost surface 1 of the cross-section circular wire 14 is fitted.
4b is projected higher than the outer surface 4 of the sectoral segment wire 1 in cross section to form a protruding step t. (See Fig. 4)

(9) Further, in the low slack low wind piezoelectric wires of the above (1) to (8), the number N of twisted wires of the sectoral segment wire 1 of the outermost layer is 6≤N≤36. It is what

(10) In the low sag / wind wind piezoelectric wire of the above (5), at least two outer surface protruding segment wires 11 to be joined by the outermost layer are provided, and the protruding step t of the outer surface protruding segment wire 11 is And the central angle θ2 of the outer surface projecting segment wires 11 and 11 (FIGS. 2 and 3)
0.5 ≤ t ≤ 2.0 (mm), 20 ° ≤ θ2 ≤ 60
A value of ° is effective.

The operation resulting from the constitutions (1) to (9) is as follows. The tension-sharing core material 5 at the stranded center has a linear expansion coefficient of ^{−6 to 6} × 10 ⁻⁶ / ° C.,
In addition, a wire having a low linear expansion coefficient and a high elastic coefficient having an elastic modulus of 100 to 600 GPa is used, and a wire made of a super heat-resistant aluminum alloy or a special heat-resistant aluminum alloy is used as the outermost cross-sectional sector segment wire 1. As a result, an increase in slackness due to wire extension at high temperature is suppressed. Further, by providing the groove portion 3 having an arcuate cross section on the surface side of the adjoining portion 2 of the sector segment wire 1 having a cross section that is matched with the outermost layer, the increase in wind pressure load applied to the wire is reduced even under a high wind speed such as during a typhoon.

The tension-sharing core material 5 has a low linear expansion coefficient made of Invar wire or inorganic fiber such as silicon carbide fiber, carbon fiber and alumina fiber, or organic fiber such as aramid fiber,
By using a composite wire that has been plated or coated with a metal from the group consisting of aluminum, zinc, chrome, or copper on the surface of a thin wire with a high elastic modulus, tension members can be used even when the peak current is reached in summer. The temperature elongation of (tension-sharing core material) is 1/3 to 1/1 / the elongation of the normal ACSR steel core.
It becomes 4 and the sagging is greatly suppressed.

In addition, the outermost cross-section fan-shaped segment wire 1
If a super heat-resistant aluminum alloy element wire is used for the aluminum wire twisting layer 6 in the middle between the twisting layer and the central tension-sharing core material 5, the current capacity is doubled. In the case of an electric wire using an Invar wire with a small linear expansion coefficient as the tension-sharing core material, the stress sharing of the aluminum part is usually 0 at the transition point around 90 ° C., and at temperatures above that, only the Invar wire is used. The tension is calculated using the expansion coefficient αs and the elastic coefficient Es.

An electric wire in which a groove portion 3 having an arcuate cross section is provided on the surface side of the adjacent portion 2 of the sectoral segment wire 1 having a cross section formed by the outermost layer forms a spiral groove in the longitudinal direction. When wind hits the overhead wire having the groove 3 having an arcuate cross section, the boundary layer of the laminar flow flowing on the surface passes through the groove part 3 having an arcuate cross section and moves to the leeward side, and the separation point P is leeward. Wind power load is reduced by moving to the rear side of the wire.

In the case where the circular-arc groove section 3 is an elliptic circular curved surface with a gentle slope, the boundary layer passing through the circular-section groove section 3 passes without being disturbed, and the separation point P is leeward. Move to the side. As shown in FIG. 5, when the overhead wire is exposed to wind and the laminar flow of the air flow F flows along the outer peripheral surface 4 of the sectoral segment wire 1 of the outermost layer forming the surface of the wire, its outer circumference A boundary layer B having a thin layer thickness δ is formed on the surface 4, flows to the leeward side as indicated by the flow line arrow f, and the flow velocity distribution of the boundary layer B at each position on the outer peripheral surface 4 is B1 → B
It changes like 2 → B3 → B4. When the boundary layer passes through the groove 3 with a gentle gradient in cross section, it becomes B2,
A vortex flow C is generated in the arcuate groove portion 3 to reduce consumption of kinetic energy of the boundary layer B passing through the arcuate groove portion 3,
Due to this reduction in energy consumption, the separation of the boundary layer from the surface of the electric wire caused by the consumption of kinetic energy is delayed, and the separation point P flows to the leeward side and moves to the rear side of the electric wire to separate. A low-pressure region is formed downstream of the separation point P, a backflow R is generated, and a boundary with this region becomes a discontinuous surface SD. In this way, the boundary layer passing through the groove 3 having the arcuate cross section moves to the leeward side without being disturbed and the separation point P moves to the leeward side, so that the high air pressure on the windward side of the wire also extends to the rear side of the wire. As a result, the wind pressure load on the wire is reduced. Since the adjacent corners on the surface side of the adjacent portion 2 of the sectoral segment wire 1 in cross section are located at the bottom of the arc-shaped groove portion 3 in cross section, even if there is a step on the surface side of the adjacent portion 2, the effect is the cross section circle. The influence on the boundary layer on the surface of the electric wire is reduced due to the vortex C in the groove 3, which is limited to the flow in the arc-shaped groove 3.

When the arcuate surface of the arcuate cross-section groove portion 3 provided on the surface side of the adjoining portion 2 of the sectoral segment wire 1 of the outermost layer is semicircular, the boundary layer passing through this semicircular groove portion in cross section is positive. Turbulent flow and passes, and the separation point shifts to the leeward side.
When the circular arc of the arcuate cross-section groove portion 3 is approximated to a semi-circular shape, as shown in FIG. 6, the thin layer thickness δ of the laminar flow that flows on the outer peripheral surface 4 of the sectoral segment wire of the outermost layer forming the electric wire surface. In the boundary layer B, the flow velocity distribution at each position on the outer peripheral surface 4 changes like B1 → B2 → B3 → B4, and a vortex C is generated in the groove 3a having a semi-circular cross section to become like B2. When the leeward side shoulder portion 3b of the semicircular groove portion 3a is crossed, the shoulder portion 3b serves as a base point of turbulence and turbulence occurs in the boundary layer of the layer thickness δ '. Therefore, strong mixing turbulence occurs in the boundary layer, the separation point P shifts to the leeward side, and the backflow R occurs downstream of the discontinuous surface SD.
Occurs in a low pressure region, and high air pressure on the windward side of the wire is guided to the leeward side of the wire, reducing the wind pressure load on the wire. Moreover, since the arcuate cross-section groove portion 3 forms a spiral groove in the electric wire longitudinal direction on the outer peripheral surface of the electric wire by twisting the cross-section fan-shaped segment wires of the outermost layer, the flow of the air flow along the spiral groove occurs and the wake flow occurs. The flow mixing on the side is activated, and the wake region behind the wire is reduced, which also causes a reduction in wind pressure load.

As described above, by providing the groove section 3 having an arcuate cross section on the surface side of the adjacent section 2 of the sectoral segment wire 1 having the outermost cross section, the vortex flow in the arcuate groove section 3 has a kinetic energy of the boundary layer. When the separation point is moved backward and the arc surface of the groove portion 3 having an arcuate cross section is approximated to a semi-circular shape, the shoulder portion of the groove serves as a base point of turbulence of the boundary layer, The boundary layer becomes turbulent and the separation point is moved to the leeward side, and the rearward movement of the separation point reduces the drag coefficient.

The groove width L of the arcuate cross-section groove portion 3 provided on the surface side of the adjoining portion 2 of the fan-shaped segment wire element 1 to be fitted by the outermost layer and the width M of the non-groove portion on the surface of the fan-shaped segment wire element 1 are provided.
If the ratio L / M is less than 0.1, the width of the groove portion 3 is too narrow and the effect of providing the arc-shaped groove portion 3 cannot be sufficiently obtained.
When it exceeds 5, the surface of the overhead wire is significantly roughened and the effect of reducing the wind pressure is small. The L / M is 0.10 ≦ L / M ≦
By setting it to 1.55, a sufficient wind pressure reducing effect can be obtained.

The maximum depth H of the groove of the above-mentioned groove portion 3 having an arcuate cross section
Is the ratio H / D of the maximum depth H and the diameter D of the wire is 0.0
When it is 055 or less, the effect of reducing the influence of the eddy current C in the groove portion 3 on the boundary layer on the surface of the electric wire when the boundary layer passes through the groove portion 3 having an arcuate cross section is small. When H / D exceeds 0.082, the surface of the wire is significantly roughened and the effect of reducing wind pressure is small. Therefore, this H / D is 0.0055 ≦ D / H ≦
The range of 0.082 is preferable.

Wind noise generated when wind blows on the electric wire by making the outer surface 7 of the fan-shaped segment wire 11 having a cross section fitted to the outermost layer higher than the outer surface 4 of the fan-shaped segment wire 1 having another cross section. Is reduced. The height t of the protruding step at which the outer surface 7 of this outer surface protruding segment wire 11 projects more than the outer surface 4 of another segment wire 1 is
If it is less than 0.5 mm, the effect of reducing wind noise is small and it is from 4 mm to
If it is 5 mm or more, corona noise will increase, so 0.5-
5.0 mm, preferably 0.5 mm ≦ t ≦ 2.0 mm
It is good to do.

The outermost cross-sectional sectoral segment wire 1
The height t of the protruding step of the outer surface protruding segment element wire 11 protruding higher than the outer surface 4 of the above is made much lower than the protruding height of the conventional low noise electric wire, so The lift force is remarkably lowered, and so-called galloping vibration of low frequency and large amplitude is less likely to occur.

When the outer surface of the segment wire having a fan-shaped cross section is projected, when the wind hits the protruding shoulder, a vortex is easily generated and the wind pressure increases, but the outer surface projecting segment wire groups 11 and 11 are separated from each other. Opposite shoulders 12, 12
In addition, since the deflector angle is formed so that the protruding slope of the shoulder portion is a gentle slope surface, vortex does not occur even if wind hits the shoulder portion. If the deflector angle θ is 15 ° or less or 60 ° or more, the effect is small. Therefore, 15 ° ≦ θ ≦ 6
A range of 0 ° is preferred. The outer surface projecting segment wires 11 and 11 together with the deflector angles provided on the shoulders 12 and 12 thereof, and the arcuate cross-sectional groove portion 9 provided on the surface side of the adjacent portion 8 cause light rain under a high electric field. The corona noise during use is reduced.

As in the structure (8) (embodiment shown in FIG. 4), the arcuate cross-section groove portion 3 provided on the surface side of the segment wire adjoining portion 2 of the outermost layer has a semicircular arc shape. The semi-circular groove part 3a having a circular cross-section, and by fitting the strand 14 having a circular cross-section into at least one of the semi-circular groove parts 3a of the outermost layer and fitting them together. The groove portion 3a having a semicircular cross section positively makes the boundary layer passing therethrough turbulent to move the separation point to the leeward side and reduce the wind pressure load applied to the electric wire. Also, this semi-circular groove portion 3
The circular cross-section wire 14 fitted in a reduces wind noise. The semicircular shape of the groove 3a having a semicircular cross section is suitable for fitting the strand 14 having a circular cross section.

If the number of stranded wires of the sector-shaped segment wire 1 of the outermost layer, that is, the number of spiral grooves of the arcuate cross-section groove portion 3 formed spirally in the electric wire outer peripheral surface in the electric wire longitudinal direction is less than 6, the electric wire outer peripheral surface is formed. In this case, the space between the spiral grooves having an arcuate cross section is too widened to reduce the effect of reducing the wind pressure. When the number exceeds 36, the surface of the wire is significantly roughened and the effect of reducing the wind pressure cannot be sufficiently obtained. Therefore, the number of twisted wires of the sector-shaped segment wire 1 of the outermost layer is preferably 6 or more and 36 or less.

The central angle θ 2 of the outer surface projecting segment wires 11 and 11 in the low sag / low wind piezoelectric wire (5) is
20 ° ≤ θ2 ≤ 6 depending on the number of outer segment wires
The range of 0 ° is preferable for preventing corona noise.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 are sectional views of electric wires showing respective embodiments of the low slack low wind piezoelectric wire of the present invention. The low sag and low wind piezoelectric wire of the first embodiment of the present invention shown in FIG.
The linear material that constitutes the core of tension-sharing core 5 has a linear expansion coefficient of ^{−6 to 6} × 10 ⁻⁶ / ° C. and an elastic coefficient of 1
The Invar wire is made of an Invar type alloy having a low linear expansion coefficient of 00 to 600 GPa and a high elastic coefficient. A super-heat-resistant aluminum alloy wire 6 is twisted around the tension-sharing core material 5, and a plurality of fan-shaped segment wires 1 having a cross-section made of a super-heat-resistant aluminum alloy are wound on the outermost layer of the outer circumference of the twisted core material 5 to reduce the low sag of the present invention. The low wind piezoelectric wire 10 is configured. The electric wire configured in this manner is a low wind pressure Invar-core super heat-resistant aluminum alloy stranded wire, which is hereinafter referred to as LP-ZTACIR in the present invention. A so-called special heat-resistant aluminum alloy may be used in place of the above-mentioned super heat-resistant aluminum alloy, which is a low wind pressure Invar core special heat-resistant aluminum alloy twisted wire and is hereinafter referred to as LP-XTACIR.

Table 1 below shows the constituent materials of the LP-ZTACIR and LP-XTACIR in the low-sagility low-wind piezoelectric wire of the present invention.

[0037]

[Table 1]

Further, LP-ZTACI and LP-X
The mechanical properties and allowable temperature characteristics of TACIR are
It is shown in Table 2 below in comparison with CSR.

[0039]

[Table 2]

The coefficient of linear expansion is -6 to 6 × 10.
^As a wire constituting the tension-sharing core material 5 having a low linear expansion coefficient and a high elastic modulus of ^-6 / ° C and an elastic modulus of 100600 GPa, the surface of an inorganic fiber such as silicon carbide fiber, carbon fiber or alumina fiber, A composite wire material having heat resistance, which is plated or coated with a metal selected from the group consisting of aluminum, zinc, chrome, and copper, is used, and the pre-formed wires are twisted together to form the tension-sharing core material 5. .

As the wire material constituting the tension-sharing core material 5 having a low linear expansion coefficient and a high elastic coefficient, a composite wire material in which a heat-resistant organic fiber such as aramid fiber is plated or coated with metal, or FRP wire made by impregnating a heat-resistant organic fiber such as aramid fiber with a resin and solidifying it, or this FR
The tension-sharing core material 5 is configured by using a composite wire material in which a P wire material is coated with aluminum or other metal for strengthening weather resistance.
The low linear expansion coefficient is ^{−6 to 6} × 10 ⁻⁶ / ° C., and the high elastic coefficient is a value of about 100 to 600 GPa.

The low slack low wind piezoelectric wire 10 according to the first embodiment of the present invention shown in FIG. 1 has a fan-shaped cross section composed of a super heat resistant aluminum alloy wire or a special heat resistant aluminum alloy wire to be matched depending on the outermost layer thereof. On the electric wire surface side of the adjacent portion 2 of each segment wire, a groove portion 3 having a concave arc-shaped cross section such as a circular arc or an elliptical arc is provided. The groove portion 3 having an arcuate cross section forms a spiral groove in the electric wire longitudinal direction on the outer peripheral surface of the electric wire 10 by twisting the wires 1. When the electric wire 10 is exposed to wind, the boundary layer of the laminar flow flowing on the surface of the electric wire 10 has a circular groove section 3
To move to the leeward side, the separation point moves to the rearward side of the electric wire on the leeward side, and the wind pressure load is reduced.

The above-mentioned outermost layer cross-section fan-shaped segment wire 1
The number of twists, that is, the number of grooves spirally formed in the longitudinal direction on the outer peripheral surface of the electric wire by the groove portion 3 having an arcuate cross section is preferably 6 or more and 36 or less. The embodiment shown in FIG. 1 is an example in which twelve wires are combined. The groove width L of the concave arcuate groove 3 is L / M 0.10 ≦ L / M ≦, where M is the width of the non-groove on the surface of the fan-shaped segment wire 1.
It is desirable that the range is 1.55. Further, regarding the depth of the groove portion 3 having an arcuate cross section, the maximum depth is H and the diameter of the electric wire is D.
Then, H / D is 0.0055 ≦ D / H ≦ 0.082
Is desirably within the range.

FIG. 2 shows a low slack low wind piezoelectric wire 10 according to a second embodiment of the present invention. In the second embodiment, a super heat-resistant aluminum alloy stranded wire 6 is twisted around an invar steel stranded wire 5 which is a central core material for tension sharing, and a super heat-resistant aluminum alloy or a special heat-resistant aluminum alloy is used as the outermost layer of the outer circumference. Although the segment wires 1 each having a fan-shaped cross section made of an aluminum alloy are twisted together as in the first embodiment shown in FIG. 1, at least two of the segment wire segments having a fan-shaped cross section of the outermost layer are combined.
The segment wires 11, 11 having a fan-shaped cross section of the book have an outer surface 7 protruding higher than the outer surface 4 of another segment wire 1. The protruding height t that forms a step protruding higher than the outer surface 4 of the other segment wire 1 is 0.5 mm to 5 mm.
mm, preferably 0.5 mm to 2 mm.

The outer surface projecting segment wire groups 11, 11 arranged in contact with each other at the two shoulder portions 12, 12 on the opposite sides to each other are formed in order to prevent the generation of eddy currents which tend to occur in these shoulder portions. A deflector angle θ is provided to make the protruding slope a gentle slope. This deflector angle θ is 15 ° ≦ θ ≦
It is desirable that the range is 60 °. In FIG. 2, the angle θ is shown only in the left shoulder 12 of the segment wire group 11 on the left side of the two outer surface projecting segment wire groups 11 arranged side by side, but the right shoulder 12 of the segment wire group 11 on the right side is illustrated. Similarly, the angle θ is also formed.

Θ 2 shown in FIG. 2 is a central angle formed by both side surfaces of the outer surface projecting segment wires 11 and 11 group of the number of which are juxtaposed with each other.
The central angle θ 2 of the 11th group depends on the number of outer segment wire strands, but is preferably in the range of 20 ° ≦ θ 2 ≦ 60 ° from the viewpoint of preventing corona noise.

Also in the second embodiment shown in FIG. 2, in the same manner as in the first embodiment, a groove portion 3 having an arcuate cross section is provided on the electric wire surface side of the adjacent portion 2 of the sectoral segment wire 1 in cross section. A groove portion 9 having an arcuate cross section is also provided on the surface side of the adjacent portion 8 between the outer surface protruding segment wires 11 and 11. The maximum depth H of each groove 3 and the groove 9 is the same as that of the embodiment shown in FIG. 1, and the groove width L of each groove 3 and the groove 9 and the non-uniformity of the surface of the segment wire segments 1 and 11 in cross section. The ratio L / M to the width M of the groove is similar to that of the embodiment shown in FIG.

FIG. 3 shows a low sag / low wind piezoelectric wire 10 according to a third embodiment of the present invention, and the same reference numerals as those in FIG. 2 indicate the same parts. This third embodiment is similar to the second embodiment shown in FIG.
2 is a modified example of the embodiment of FIG. 2, in which the Invar steel twisted core wire 5 in FIG. 2 is an aluminum covered steel wire, and is made of a super heat resistant aluminum alloy or a special heat resistant aluminum alloy instead of the super heat resistant aluminum alloy twisted wire 6 to be fitted around it This is a form in which the fan-shaped cross-section segment wires 13 are twisted together. In the electric wire according to the third embodiment of FIG. 3, the outer surface of at least two sector-shaped segment wires 11, 11 of the sector-shaped segment wire of the outermost layer is higher than that of the other segment wires 1. A step is formed that protrudes as high as the protrusion height t, and this step t is 0.5
mm to 5 mm, preferably 0.5 mm to 2 mm, providing the deflector angle θ on both shoulders 12, 12 on the opposite side of the outer surface projecting segment element wire groups 11, 11. Providing a groove portion 9 having an arcuate cross section on the surface side of the adjacent portions 8 of the lines 11 and 11, the central angle θ2 of both side surfaces of the outer surface projecting segment wires 11 and 11
Is within the range of 20 ° ≦ θ2 ≦ 60 °.
It is similar to the second embodiment shown in FIG.

In the second and third embodiments, the electric wire 1
Outer surface protruding segment wire 11 protruding from the outer peripheral surface of 0
Reduces wind noise. In the second and third embodiments,
In the outermost layer, the number N of twisted cross-section fan-shaped segment wires 1 is N, and the number n of outer-surface protruding segment wires 11 is n, and n / N is in the range of 0.025 ≦ n / N ≦ 0.5. be able to.

FIG. 4 shows a low sag / low wind piezoelectric wire 10 according to a fourth embodiment of the present invention, and the same reference numerals as those in FIG. 1 indicate the same parts. In the fourth embodiment, instead of the super heat-resistant aluminum alloy twisted wire 6 in which the Invar steel twisted core wire 5 is galvanized, the cross-section fan-shaped segment wire made of a super heat-resistant aluminum alloy or a special heat-resistant aluminum alloy is used. Tying 13 together is the same as in the third embodiment, but is a form in which the fan-shaped segment wire segments in cross section are formed into two layers 13a and 13b. In the fourth embodiment, an arcuate groove 3 having a cross section provided on the electric wire surface side of the adjacent portion 2 of the sectoral segment wire 1 having the outermost layer is formed in a groove 3a having a semicircular cross section, and the cross section of the outermost layer is formed. The wire 14 having a circular cross section is fitted into at least one of the semicircular groove sections 3a of the semicircular groove sections 3a. t is a projection height at which the outermost surface 14b of the circular wire 14 fitted in the semicircular groove portion 3a of the cross section projects higher than the outer surface 4 of the sector wire element 1 in cross section, and the second embodiment is used. Similarly to the above, the protrusion height t is preferably in the range of 0.5 mm to 5 mm, and more preferably 0.5 mm to 2 mm. L
Is the groove width of the semi-circular groove portion 3a in cross section, M is the width of the non-groove portion on the surface of the sector wire segment 1 in cross section, and the ratio L / M thereof is the same as in the first embodiment. In this fourth embodiment,
When the boundary layer passes through the semicircular groove 3a in cross section and crosses the leeward side shoulder, the shoulder becomes a turbulence base point and is actively turbulent, and the separation point moves to the leeward side and wind pressure is applied to the wire. The load is reduced. Further, the circular wire 14 having a circular cross section protruding higher than the outer surface of the segment wire 1 having a fan-shaped cross section reduces wind noise.

A wind tunnel experiment was conducted on the low sag and low wind piezoelectric wire of the first embodiment of the present invention shown in FIG. The electric wire of the type shown in FIG. 1 has a diameter D of 36.6 mm.
A φ-LP-XTACIR is created, and the number N of the sector-shaped segment wire 1 in the outermost layer, the groove width L of the arc-shaped groove portion 3 in the cross section,
The maximum depth H of the groove 3 was variously changed, and the drag coefficient was measured within a Reynolds number of 1.2 × 10 ^{4 to} 9.9 × 10 ⁴ . For comparison, a wind tunnel experiment was also performed on a conventional ordinary steel-core aluminum stranded wire (ACSR) in which a circular-section aluminum wire was twisted around the steel core. The Reynolds number Re is Re = ρUD / μ (where ρ is the air density,
U is the velocity of air, D is the diameter of the wire, and μ is the viscosity coefficient. The drag coefficient Cd is Cd = 2d / (ρU ² A)
(Where d is the force received by the wire and A is the windward projected area of the wire). The results of this experiment are as shown in FIGS.

In FIG. 7, the depth H of the groove portion 3 having an arcuate cross section is 1.
0 mm (H / D = 0.027), the groove diameter R of the arcuate groove 3 (the radius of the arc of the arcuate groove 3) is set to 1.0 mm, and the number of grooves of the arcuate groove 3, that is, the outermost layer The relationship between the drag coefficient Cd and the Reynolds number Re when the number N of twisted cross-section fan-shaped segment wires 1 is changed is shown.
According to this FIG. 7, under the condition of Reynolds number Re of 5 × 10 ⁴ (about 20 m / s) or more, where the influence of wind pressure applied to the electric wire becomes a problem, all the electric wires of the present invention have smaller drag coefficient Cd than the conventional product. It can be seen that the area exists. In particular, when the number of grooves N is 6 or more and 36 or less, the drag coefficient Cd is significantly reduced.

In FIG. 8, the number N of grooves in the arcuate section groove 3 (the number of fan-shaped segment wire segments in the outermost layer) N is 10
Book, the depth H of the groove 3 is 0.3 mm (H / D = 0.00
82), and the ratio L / M of the groove width L of the concave arcuate groove section 3 to the width M of the non-groove section on the surface of the fan-shaped segment wire 1 in section.
Drag coefficient Cd and Reynolds number Re when changing
The relationship is shown below. From this FIG. 8, the Reynolds number Re is 5
Under the condition of × 10 ⁴ or more, the overhead wire of the present invention
It can be seen that there is a region where the drag coefficient Cd is small in the range of 0.10 ≦ L / M ≦ 1.55.

FIG. 9 shows a case where the number N of grooves of the arcuate groove 3 in cross section is 24, the depth H of the groove 3 is set to 0.2 mm, and the above L / M is changed. The relationship between the drag coefficient Cd and the Reynolds number Re is shown. From FIG. 9, it is understood that under the condition that the Reynolds number Re is 5 × 10 ⁴ or more, the overhead wire of the present invention has a region where the drag coefficient Cd is smaller than that of the conventional product. In particular, when L / M is 1.5 or less and 0.6 or more, the drag coefficient Cd is small over the entire region.

In FIG. 10, the above L / M is set to 0.75, the number N of grooves is set to 12, and the depth H of the groove 3 is set to 0.15.
The relationship between the drag coefficient Cd and the Reynolds number Re when changed to ˜3.0 mm (H / D = 0.0041 to 0.082) is shown. From this FIG. 10, the Reynolds number Re is 5
Under the condition of × 10 ⁴ or more, it is understood that the overhead wire of the present invention has a region where the drag coefficient Cd is smaller than that of the conventional product.

FIG. 11 shows the drag coefficient Cd and the Reynolds number Re when the L / M is set to 1.2, the number of grooves N is set to 24, and the depth H of the groove 3 is changed. Show the relationship. From FIG. 11, under the condition that the Reynolds number Re is 5 × 10 ⁴ or more, the overhead wire of the present invention has a small drag coefficient Cd in the range where the depth H of the groove portion 3 having an arcuate cross section is 0.5 to 5 mm.

FIG. 12 shows that when the L / M is set to 1.2, the depth H of the groove 3 is set to 2.0 mm, and the number N of the grooves is changed, the drag coefficient Cd and the Reynolds number Re are shown. Shows the relationship. From this FIG. 12, the Reynolds number Re is 5 × 1.
It is understood that under the conditions of 0 ⁴ or more, the overhead wire of the present invention has a smaller drag coefficient Cd than the conventional product.

FIG. 13 shows a noise level and a frequency characteristic at a wind speed of 20 m / s, which is obtained by comparing and comparing the wind noise generated when wind blows on the electric wire with the electric wire of the present invention and a conventional product. The electric wire of the present invention used in this experiment is an electric wire equivalent to LP-XTACIR 610 mm ^{2 of the} type shown in FIG. 3, and has an outer diameter D of 34.2 mm and other segment of the outer surface protruding segment wire 11 in FIG. The protrusion height t protruding from the outer surface of the wire 1 is 1 mm, and the deflector angle θ is 4
5 °, outer surface protruding segment wires 11, the central angle θ2 of the 11 group is 40 °, the number of grooves (the number of outermost segment wire segments) N
18 wires, the depth H of the groove 3 is 2.0 mm, and the twisted segment wires have a pitch length of 360 mm. As a comparative example, the conventional ACSR 610 mm ² and the wire of the type shown in FIG. 15 are used. I did a comparative experiment. From this experimental result, the overhead wire of the present invention has a noise level of 10
15~22db [A] may also have decreased significantly was confirmed in the vicinity 0~130H _Z. The central angle .theta.2 of the outer surface projecting segment wires 11 and 11 group is preferably in the range of 20.degree.

FIG. 14 shows wind noise characteristics (FIG. 13) of an electric wire having no step as shown in FIG. 1 and an electric wire having step t as shown in FIGS. It is the result of actually measuring the wind noise level of the dominant frequency when changing it. In FIG. 14, the wind noise level at t = 0 mm is the wind noise level in the case of the stepless electric wire in FIG. It was found that, with respect to the electric wire of FIG. 1, when the step was gradually increased, the wind noise prevention effect of the step was saturated in the range of t> 1.5 mm. When a wind speed of 20 m / s, which is perceived as noise by a person, is indistinguishable from the surrounding noise, and a lower wind speed region is a problem, and if the wind noise level is 10 dB lower than that of the electric wire of FIG. Since it is considered that there is almost no problem, it is sufficient from the actual measurement result of FIG. 14 that the effective range of the step difference t is 0.5 ≦ t ≦ 2.0 (mm).

The outline shapes of the electric wire cross sections of a to f shown in FIG. 15 and the electric wire cross sections of g to j shown in FIG. 16 are the same as those of the electric wire specimen used when performing the fluid analysis by the supercomputer. It is a cross-sectional model. Each model is characterized by the number of arcuate grooves formed on the surface of the wire, the depth and width of the groove, and the size and number of vortices formed behind the wire cross section and the separation point of vortices differ due to these differences. Was simulated.

The above-mentioned low sag / low wind piezoelectric wire of the present invention is 500
Applying low sag low wind wires of the present invention to four-conductor 2 lines of the transmission line of the kv-class ACSR810mm ^2, whereas the design wind load, conventionally is 100 kgf / mm ^2,
The present invention can be reduced to 60 kgf / mm ² , the current capacity can be doubled, and the increase in sag can be suppressed, so that the weight of the steel tower is 7%, and the total construction cost is about 5%.
Can be reduced.

[0062]

As described above, in the low sag and low wind piezoelectric wire of the present invention, since the arcuate groove section is provided in the adjoining portion of the sectoral segment wire of the outermost layer, the segment wire adjoining portion of the outer peripheral surface of the wire. The conventional V-shaped groove does not have a stepped portion, but has a concave arcuate surface, and the separation point of the boundary layer where the wind flows on the surface moves to the leeward side of the wire, and the wind pressure load can be reduced.
Moreover, a low wind pressure electric wire can be easily manufactured at low cost.

Further, the ratio L / M of the groove width L of the arcuate section groove section and the width M of the non-groove section on the surface of the sector wire segment in section is given by:
The ratio H / D between the maximum depth H of the groove portion 3 and the wire diameter D is set to 0.0055 in the range of 0.10 ≦ L / M ≦ 1.55.
An effective wind pressure load reducing effect can be obtained by setting the range of ≦ D / H ≦ 0.082 and setting the number of stranded wires of the segment wire having a fan-shaped cross section of the outermost layer to 6 or more and 36 or less.

Further, since the low-sagility low-wind piezoelectric wire of the present invention is provided with the outer surface projecting segment wire having the outer surface projecting in the twisting of the cross-section fan-shaped segment wires of the outermost layer, the wind pressure load is reduced. It is possible to reduce wind noise and corona noise during light rain. Further, the protrusion height of the outer surface projecting segment wire is set in the range of 0.5 to 5 mm, preferably 0.5 to 2 mm, and the deflector angle θ of 15 ° ≦ θ ≦ 60 ° on both shoulders of the outer surface projecting segment wire. By providing the, it is possible to increase the wind pressure load reducing effect.

Further, since the height of the protruding step of the outer surface protruding segment wire protruding above the outer surface of the outermost layer fan-shaped segment wire is made much lower than that of the conventional low noise electric wire. The lift force when receiving an oblique wind is significantly reduced, and so-called galloping vibration of low frequency and large amplitude is less likely to occur.

In addition, since the low-relaxation low-wind piezoelectric wire of the present invention uses the Invar wire for the steel core and the segment wire of the super heat-resistant aluminum alloy or the special heat-resistant aluminum alloy for the outermost layer, Can be greatly suppressed. Therefore, the amount of rolling when the overhead wire receives a strong wind from the lateral direction can be greatly suppressed in combination with the low wind pressure structure. As a result, the tower height, arm width, steel tower foundation, etc. of the tower can be significantly reduced, and the construction cost of the transmission line can be greatly saved. This is an effect not seen in conventional Invar electric wires and low-wind piezoelectric wires, and it is possible to easily realize further compactification of steel towers such as large bundle diameter multi-conductor transmission lines and 1000KV UHV transmission lines to be constructed in the future. Is.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

FIG. 3 is a diagram showing a third embodiment of the present invention.

FIG. 4 is a diagram showing a fourth embodiment of the present invention.

FIG. 5 is an explanatory view of a state of a boundary layer in a groove section having an arc cross section of a wind flow.

FIG. 6 is an explanatory view of a state of a boundary layer in a groove having a semicircular cross section of a wind flow.

FIG. 7 is a diagram showing the relationship between the drag coefficient and the Reynolds number when the depth of a groove having an arcuate cross section is set and the number of grooves is changed.

FIG. 8 shows the groove width L and the non-groove portion M by setting the number of grooves and the depth of the groove portion.
Showing the relationship between the drag coefficient and Reynolds number when the ratio L / M with the width of

FIG. 9 is a diagram showing the relationship between the drag coefficient and the Reynolds number when the set values of the number of grooves and the depth of the groove are changed and the change of L / M is changed.

FIG. 10 is a diagram showing the relationship between the drag coefficient and the Reynolds number when L / M and the number of grooves are set and the depth of the groove is changed.

FIG. 11 is a diagram showing the relationship between the drag coefficient and the Reynolds number when L / M and the number of grooves are set and the change in the depth of the groove is changed.

FIG. 12 is a diagram showing the relationship between the drag coefficient and the Reynolds number when L / M and the depth of the groove are set and the number of grooves is changed.

FIG. 13 is a diagram showing the noise level and frequency characteristics of the wind noise comparison test results of the overhead wire of the present invention and the conventional product.

FIG. 14 is a diagram showing a relationship between a step t and a predominant frequency wind sound level.

FIG. 15 is a cross-sectional view showing another shape of the electric wire test piece subjected to the wind tunnel test.

FIG. 16 is a cross-sectional view showing still another shape of the electric wire test piece subjected to the wind tunnel experiment.

FIG. 17 is a diagram showing an example of a conventional overhead wire.

[Explanation of symbols]

 1: Cross-section fan-shaped segment wire 2, 8: Adjacent part 3, 9: Cross-section arc-shaped groove part 3a: Cross-section semicircular groove part 5: Tension sharing core material 4, 7: Outer surface 10: Electric wire 11: Outer surface protruding segment element Line 12: Shoulder 14: Circular wire having a circular section D: Diameter of electric wire H: Maximum depth of groove 3 L: Width of groove 3 M: Width of non-groove N: Number of grooves (= number of segment wires having a fan-shaped cross section) ) Θ: Deflector angle θ2: Center angle of protruding segment wire

Front page continuation (72) Inventor Takeo Munakata 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Naoshi Kikuchi 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Industry Co., Ltd.

Claims (9)

[Claims] 1. The tension-sharing core material has a linear expansion coefficient of −
^{6 to 6} × 10 ⁻⁶ / ° C. and an elastic modulus of 100 to 60
Using a wire with a low coefficient of linear expansion and a high elastic coefficient of 0 GPa, combine a plurality of sector-shaped segment wires made of super heat-resistant aluminum alloy or special heat-resistant aluminum alloy in the outermost layer, and adjoin each twisted segment wire A low slack low wind piezoelectric wire, characterized in that a groove portion having an arcuate cross section is provided on the surface side of the portion. 2. The tension-sharing core material is made of Invar wire or inorganic fiber such as silicon carbide fiber, carbon fiber, alumina fiber, or organic filaments such as aramid fiber. 2. The low-sagility low-wind piezoelectric wire according to claim 1, wherein a composite wire material plated or coated with any metal of the group of copper or the like is used. 3. The ratio L / M of the groove width L of the arcuate section groove section and the width M of the non-groove section on the surface of the segment wire having a fan-shaped section is 0.
The low sag and low wind piezoelectric wire according to claim 1 or 2, wherein 10 ≦ L / M ≦ 1.55. 4. The ratio H / D of the maximum depth H of the arcuate section groove and the overhead wire diameter D is 0.0055 ≦ H / D ≦ 0.082.
The low sag low wind piezoelectric wire according to claim 1, 2 or 3. 5. A protruding step is formed in which at least one segment wire among the plurality of sector-shaped segment wires to be joined by the outermost layer is formed so that its outer surface projects higher than the outer surfaces of other segment wires. 5. The low slack low wind piezoelectric wire according to claim 1, wherein the outer surface protruding segment element wire is used. 6. A protruding step t of an outer surface protruding segment wire.
0.5-5.0 mm, preferably 0.5-2.0 mm
The low slack low wind piezoelectric wire according to claim 5. 7. The low sag and low wind pressure according to claim 5 or 6, characterized in that a deflector angle θ of 15 ° ≦ θ ≦ 60 ° is provided on a shoulder portion formed with a protruding step of the outer surface protruding segment element wire. Electrical wire. 8. A groove on the surface side of the section adjacent to the sectoral segment wire of the outermost layer is formed in a semicircular groove section, and at least one of the semicircular groove sections of the outermost layer has a cross section in the semicircular groove section. 2. A protrusion step is formed by fitting a circular wire and projecting an outermost surface of the circular wire having a cross section higher than an outer surface of the segment wire having a fan-shaped cross section.
2, 3, 4, 5 or 6 low sag low wind piezoelectric wire. 9. The low sag and low wind piezoelectric wire according to any one of claims 1 to 8, wherein the number N of stranded wires of the sector-shaped segment wire of the outermost layer is 6 ≦ N ≦ 36.