JP5389875B2 - Low wind piezoelectric wire with fins - Google Patents

Description

  More particularly, the present invention relates to a low-winding piezoelectric wire with fins that is installed in an aerial space. More specifically, the air resistance against wind pressure is reduced, thereby reducing the wind pressure load of the electric wire that is installed in the aerial space. The present invention relates to a low-winding piezoelectric wire with a fin that reduces a burden received by a support such as a fin.

Since an overhead electric wire installed on a steel tower or a power pole receives a large wind pressure load due to the wind pressure, a support such as a steel tower or a power pole supporting the overhead electric cable is designed in consideration of the wind pressure received by the overhead electric wire. However, if the support is designed to withstand a large wind pressure load, an increase in equipment cost is inevitable. In particular, overhead wires are affected by wind pressure due to the increase in capacity due to the increased capacity. For this reason, overhead electric wires are required to reduce wind pressure loads. As a low wind piezoelectric wire that aims to reduce the wind pressure load, for example, there is a “low wind pressure insulated wire” shown in Patent Document 1. As shown in FIG. 7 , the low wind pressure insulated electric wire 200 has a large number of wave-shaped irregularities that satisfy a predetermined condition in which a crest 203 and a trough 204 are smoothly connected to the outer peripheral surface of an insulator 202 covering the conductor 201. Is provided. With this configuration, when wind is blown onto the low wind pressure insulated electric wire 200, the so-called Karman vortex generated on the downstream side of the unevenness is reduced to reduce the wind pressure load.

  Similarly, in the “low wind piezoelectric wire” shown in Patent Document 2, grooves on the coated surface satisfying predetermined conditions in parallel with the length direction and having an edge line shape in the cross section in an arc shape are provided with a predetermined interval. A plurality of them are provided.

On the other hand, as a device that suppresses the generation of Karman vortices, a “wire with fins” shown in Patent Document 3 is also known. As shown in FIGS. 8 and 9 , this finned wire 300 is a wire in which a conductor 301 is covered with an insulator 302, and a pair of jetty fins 303 are formed along the longitudinal direction of the conductor 301 on the outer peripheral surface of the insulator 302. It is intended to suppress noise caused by wind and snow on the surface of the electric wire.

Japanese Patent No. 3725408 Japanese Patent No. 2952480 JP-A-5-138710

  According to the technical standards for electrical installations, the material and structure of the support for the overhead electric lines are subject to wind pressure load of 40m / sec and the influence of weather changes, vibrations, shocks and other external environments normally assumed at the installation location. It is specified that it must be safe so that there is no risk of collapse. Therefore, in the case of the low wind piezoelectric wire of Patent Document 1 described above, the effect is exhibited at a wind speed of 40 m / sec. In the case of the low wind piezoelectric wire of Patent Document 2, the effect is obtained at a wind speed of 40 to 50 m / sec. It is formed so that an effect is exhibited.

  Of course, it is preferable to effectively reduce the wind pressure load in such a strong wind because the influence on the support such as a steel tower or a utility pole is reduced, but the electric wire is always exposed to such a strong wind. Rather, it is more likely to occur frequently, and it is more likely that the electric wire will always be exposed. For example, it does not exceed 40 m / sec. Such a low wind piezoelectric wire is more practical. Of course, it goes without saying that the material and structure of the support for the overhead electric line must be safe in accordance with the technical standards for electrical equipment so that there is no risk of collapse at a wind speed of 40 m / sec.

  In addition, in order to install in a snowy area, it is preferable that the wind pressure load is reduced, and at least a snowfall performance equal to or higher than the conventional one is provided.

  Accordingly, an object of the present invention is to reduce a wind pressure load with respect to a wind speed that is likely to occur frequently and to which the electric wire is always exposed, for example, a wind pressure of 30 to 40 m / sec. It is possible to reduce the burden received by the support such as a steel tower or a power pole that supports the wire, and at the same time, the fins can prevent the snow from adhering to the surface of the electric wires from being at least equivalent to the conventional electric wires. It is to provide an attached low wind piezoelectric wire.

In order to achieve the above object, the present invention according to claim 1 is directed to a low wind piezoelectric wire with fins in which fins are arranged on the surface of an insulator of a circular electric wire whose outer periphery is covered with an insulator. are arranged along the longitudinal direction on the outer peripheral surface of the insulator, apex with flat, it has a cross-sectional shape of Ryakukata shape with skirt spread proximally into an arc shape, and the fin from the insulator surface 16 to 32 fins having a height (H) of 0.5 to 1.0 mm are arranged at regular intervals in the circumferential direction of the insulator.

In order to achieve the above object, the present invention according to claim 2 is directed to the low wind piezoelectric wire with fin according to claim 1 , in which the height of the fin (H) is set when the outer diameter of the insulator is D ₀ . A finned low wind piezoelectric wire characterized in that a fin width (W) at a height position of ½ is calculated by the following equation [Equation 1].
[Equation 1]
_{W = 2 × D 1 × tan} (θ 1/2)
However,
D ₁ = (D _0/2 ) + (H / 2)
θ ₁ is an angle of the fin width with respect to the center of the insulator at a height position that is ½ of the height (H) of the fin, and its range is 3 to 7 °.

θ_３は、ヒレの裾部の曲率半径の中心角度である。 In order to achieve the above object, the present invention described in claim 3 is directed to the low wind piezoelectric wire with fins according to claim 1 or 2 , wherein the number of fins (N (where N is a natural number)) is expressed by the following formula [ A finned low-winding piezoelectric wire, wherein n calculated in Formula 2 is calculated by rounding up the fractional part and rounding down or rounding off.
[Equation 2]
n = 360 / (θ ₂ + θ ₄ )
However,
θ ₂ is an angle θ ₄ within an interval between adjacent fins, and θ ₄ is a fin width angle including the curvature radius of the bottom portion of the fin, and is calculated by the following equation [Equation 3].
[Equation 3]
θ ₄ = 2 × tan ⁻¹ (K ₂ / K ₁ )
K ₁ is calculated by [Equation 4], and K ₂ is calculated by [Equation 5].
[Equation 4]
K ₁ = (D _0/2 ) + K ₃
[Equation 5]
K ₂ = (W / 2) + K ₃
K ₃ is calculated by [Equation 6].

θ ₃ is the central angle of the radius of curvature of the bottom of the fin.

In order to achieve the above object, according to a fourth aspect of the present invention, in the finned low wind piezoelectric wire according to any one of the first to third aspects, the corners of the top surface of the fin are chamfered. It is characterized by.

  According to the finned low-winding piezoelectric wire according to the present invention, the insulator is arranged along the longitudinal direction on the outer peripheral surface of the insulator, and has a substantially rectangular shape with a flat top portion and a skirt extending in an arc shape on the base side. Since a plurality of fins having a cross-sectional shape are arranged at regular intervals in the circumferential direction of the insulator, the wind pressure can be easily entangled between the adjacent fins and the wind can easily flow along the fins, thereby reducing the wind pressure load. There is an effect that it can be planned.

  Moreover, according to the low wind piezoelectric wire with fins according to the present invention, there is an effect that it is possible to obtain a snowfall performance equivalent to that of a conventional electric wire while achieving a low wind pressure.

(A) is a front view of embodiment of the low wind piezoelectric wire with a fin based on this invention, (b) is the sectional view on the AA line of the low wind piezoelectric wire with a fin shown to (a). It is a partial expanded sectional view of the low wind piezoelectric wire with a fin shown in FIG.1 (b). It is explanatory drawing which shows the definition of each constant required for calculation of a fin width and a fin number. It is a figure which shows the reference position at the time of measuring fin width. It is a figure which shows the fin width angle containing the angle in the space | interval of adjacent fins, and the curvature radius of the bottom part of a fin bottom part. It is explanatory drawing of the curvature radius of the skirt part of a fin. It is sectional drawing which shows the conventional electric wire. It is a perspective view which shows the other conventional electric wire. It is a figure which shows the state which snowed on the fin of the conventional low wind piezoelectric wire in FIG.

  A preferred embodiment of a finned low wind piezoelectric wire according to the present invention will be described below in detail with reference to the drawings. 1A and 1B are diagrams showing an embodiment of a finned low wind piezoelectric wire according to the present invention, wherein FIG. 1A is a front view, and FIG. 1B is a cross-sectional view taken along line AA of the finned low wind piezoelectric wire shown in FIG. FIG. FIG. 2 is a partially enlarged sectional view of the finned low wind piezoelectric wire shown in FIG. The illustrated low wind piezoelectric wire 100 with fins includes a conductor 1 mainly composed of a metal such as copper or aluminum having excellent conductivity, and an insulator 2 having a circular cross section covering the conductor 1 with a predetermined thickness, A plurality (16 in this case) of fins 3A to 3P (hereinafter simply referred to as “fins 3”) provided in parallel with the longitudinal direction at regular intervals along the circumferential direction of the outer peripheral surface of the insulator 2; It is configured with. The number of fins 3 is not limited to 16, but any number can be formed as long as the air resistance can be reduced to obtain a desired wind pressure load. Specifically, the effect of reducing the wind pressure can be expected if the number is approximately 32.

  The insulator 2 is made of a synthetic resin material such as polyvinyl chloride, polyethylene, or crosslinked polyethylene. The fins 3 </ b> A to 3 </ b> P are manufactured, for example, by integrally forming the insulator 2 by resin molding using the die when the conductor 1 is coated on the conductor 1 through a conductor 1 on a die of a resin extrusion molding machine (not shown). Can do. The fins 3A to 3P are formed in the same shape and the same size, and their cross-sectional shapes are substantially square (square or trapezoidal) as shown in FIG. Further, the base side of the fins 3 </ b> A to 3 </ b> P has a skirt portion 11 that expands in an arc as it approaches the insulator 2. As specific sizes of the cross-sections of the fins 3A to 3P, the height H is 0.5 mm to 1.0 mm, and the width (W) size in the circumferential direction is 0.5 mm to 2.0 mm. For example, the height (H) × width (W) is 0.5 mm × 1.5 mm or the like. Furthermore, as shown in FIG. 2, the corners 10 of the top surfaces of the fins 3A to 3P are chamfered in a round shape. In the present invention, since the base side of the fin 3 is an arc-shaped skirt 11, the fin width (W) is set to a width at half the height of the fin (H).

  As described above, the plurality of fins 3 </ b> A to 3 </ b> P are linearly formed along the longitudinal direction of the insulator 2, and along the circumference of the insulator 2 as shown in FIG. Since the adjacent fins 3 </ b> A to 3 </ b> P are arranged in close proximity to each other, the wind is easy to be caught between the adjacent fins 3, and the wind flows along the fins 3 </ b> A to 3 </ b> P. It becomes easy to flow. As a result, the wind separation position can be rearward, and the Karman vortex generated behind can be reduced. As a result, the wind pressure applied to the electric wire is reduced.

Next, in the above embodiment, the fin width (W) is 0.5 mm to 2.0 mm, and the number of fins (N) is 16 of 3A to 3P, but the fin width (W) The number of fins (N) can be calculated by the following equations [Equation 1] to [Equation 6] regardless of the diameter of the insulator 2 as described below. Here, the outer diameter (diameter) of the insulator 2 is D ₀ , the height of the fin from the surface of the insulator 2 is H, and the center of the insulator 2 at the half height position of the fin height H, ie, If the angle of the width of the fin 3B at the center CE of the conductor 1 is θ ₁ , the width (W) of the fin can be calculated by [Equation 1] as shown in FIG.
[Equation 1]
_{W = 2 × D 1 × tan} (θ 1/2)

However, D ₁ = (D _0/2 ) + (H / 2), and θ ₁ is the angle of the fin width with respect to the center of the insulator at the height position of ½ of the fin height (H). Yes, the range is 3-7 degrees. The reason why θ _{1 is set} to 3 to 7 ° is that, even if it is larger or smaller than that, the amount of wind caught between adjacent fins 3 is reduced, and the wind does not easily flow along the fins 3. .

θ_３は、ヒレの裾部の曲率半径の中心角度である。尚、θ_３は８０°〜９０°であることが好ましい。
すなわち、絶縁体２の表面に配置すべきヒレ３のヒレ幅（Ｗ）、ヒレ高さ（Ｈ）、形状が特定されればあとはヒレ３を配置すべきおおよその位置関係を特定することによって絶縁体２の表面に配置すべきヒレ３の数を算出することができる。尚、上述の手順によってヒレ３の数が算出された後はその数のヒレ３を絶縁体２の表面に均等に配置することになる。そのため、ヒレ３を配置する前（ヒレ３の数を決める前）のθ_２及びθ_４とヒレ３を配置した後のθ_２及びθ_４とでは、数値が異なる場合がある。 In addition, as shown in FIG. 5, the number of fins (N (where N is a natural number)) is calculated by rounding up or rounding off the fractional part of n calculated by the following formula [Equation 2]. Can be calculated.
[Equation 2]
n = 360 / (θ ₂ + θ ₄ )
However,
θ ₂ is an angle θ ₄ within an interval between adjacent fins, and θ ₄ is a fin width angle including the curvature radius of the bottom portion of the fin, and is calculated by the following equation [Equation 3].
[Equation 3]
θ ₄ = 2 × tan ⁻¹ (K ₂ / K ₁ )
K ₁ is calculated by [Equation 4], and K ₂ is calculated by [Equation 5].
[Equation 4]
K ₁ = (D _0/2 ) + K ₃
[Equation 5]
K ₂ = (W / 2) + K ₃
K ₃ is calculated by [Equation 6].

θ ₃ is the central angle of the radius of curvature of the bottom of the fin. In addition, it is preferable that (theta) ₃ is 80 degrees-90 degrees.
That is, when the fin width (W), fin height (H), and shape of the fin 3 to be arranged on the surface of the insulator 2 are specified, the approximate positional relationship where the fin 3 is to be arranged is specified. The number of fins 3 to be arranged on the surface of the insulator 2 can be calculated. In addition, after the number of fins 3 is calculated by the above-described procedure, the number of fins 3 is evenly arranged on the surface of the insulator 2. Therefore, the numerical values may be different between θ ₂ and θ ₄ before arranging fins 3 (before determining the number of fins 3) and θ ₂ and θ ₄ after arranging fins 3.

  According to the finned low wind piezoelectric wire 100 of the present embodiment, the Karman vortex can be reduced by providing a large number of fins 3 on the outer peripheral surface of the insulator 2, whereby the wind pressure load can be reduced. effective.

  In addition, the number of fins 3 is increased compared to the conventional one, and the upper edge 10 of the fins 3 is rounded and the hem 11 has an arc shape. Has the effect of smoothing out the effect of difficult snowfall. In the snowfall area, the wind pressure load increases as the load of the electric wire increases due to snowfall. However, according to the finned low wind piezoelectric wire 100 of this embodiment, it is difficult to reach the snowfall area such as a cold region. There is an effect that the snow effect can also be expected.

  Next, specific examples of the finned low wind piezoelectric wire according to the present invention will be described. The inventors made a prototype of the low-winding piezoelectric wire 100 with fins with the number of fins 16, 18, 20, 22, 26, and 32, respectively, and conducted a wind tunnel experiment. In the low wind piezoelectric wire 100 with fins used in the experiment, the diameter of the conductor 1 is 18.6 mm, the outer diameter of the insulator 2 (the diameter of the portion where no fin is provided) is 24.6 mm, and the top of the fin 3 The outer diameter of the top was 26.6 mm, and the fin width angle was 6.71 °. Further, the height, width, and length of the fins 3 were set to 1.0 mm (height) × 1.5 (width) mm in any of the examples. On the other hand, the same wind tunnel experiment was conducted for the comparative example in which the number of fins was 8 or 4. The results are shown in Table 1. In addition, about the reduction | decrease rate, it was based on the cross-sectional electric wire whose outer diameter is 24.6 mm.

  As is clear from Table 1, in Examples 1 to 6, the effect of reducing the wind pressure load exceeding 10% was confirmed. In particular, the best results were obtained when the number of fins was 32. On the other hand, in Comparative Example 1 (the number of fins is 4), an effect of reducing the wind pressure load was recognized, but a very large effect was not recognized. In Comparative Example 2 (the number of fins was 8), the wind load increased on the contrary, and no effect was observed.

[Other embodiments]
The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from or changing the technical idea of the present invention. For example, in each of the embodiments described above, the conductor 1 is a single wire, but may be a composite conductor. Moreover, the thickness of the conductor 1 and the insulator 2 can be freely selected.

DESCRIPTION OF SYMBOLS 1 Conductor 2 Insulator 3A-3P Fin 10 Upper edge 11 Base part 100 Low wind piezoelectric wire with fin

Claims (4)

In a low-winding piezoelectric wire with fins, in which fins are arranged on the surface of the insulator of a circular electric wire whose outer periphery is covered with an insulator,
Said insulator being disposed along a longitudinal direction on the outer peripheral surface of the top portion is in planar, have a cross-sectional shape of Ryakukata shape with skirt spread proximally in an arc shape, from the insulator surface A finned low wind piezoelectric wire, wherein 16 to 32 fins having a fin height (H) of 0.5 to 1.0 mm are arranged at regular intervals in the circumferential direction of the insulator. In the low wind piezoelectric wire with a fin according to claim 1 ,
When the outer diameter of the insulator is D ₀ , the fin width (W) at a height position ½ of the height (H) of the fin is calculated by the following equation [Equation 1]. A low-winding piezoelectric wire with fins.
[Equation 1]
_{W = 2 × D 1 × tan} (θ 1/2)
However,
D ₁ = (D _0/2 ) + (H / 2)
θ ₁ is an angle of the fin width with respect to the center of the insulator at a height position that is ½ of the height (H) of the fin, and its range is 3 to 7 °. In the low wind piezoelectric wire with a fin according to claim 1 or 2 ,
The number of fins (N (where N is a natural number)) is calculated by rounding up or rounding off the fractional part of n calculated by the following formula [Equation 2]. Low wind piezoelectric wire with.
[Equation 2]
n = 360 / (θ ₂ + θ ₄ )
However,
θ ₂ is an angle θ ₄ within an interval between adjacent fins, and θ ₄ is a fin width angle including the curvature radius of the bottom portion of the fin, and is calculated by the following equation [Equation 3].
[Equation 3]
θ ₄ = 2 × tan ⁻¹ (K ₂ / K ₁ )
K ₁ is calculated by [Equation 4], and K ₂ is calculated by [Equation 5].
[Equation 4]
K ₁ = (D _0/2 ) + K ₃
[Equation 5]
K ₂ = (W / 2) + K ₃
K ₃ is calculated by [Equation 6].

θ ₃ is the central angle of the radius of curvature of the bottom of the fin. In the low wind piezoelectric wire with a fin according to any one of claims 1 to 3 ,
The fin is a finned low wind piezoelectric wire characterized in that a corner portion of the top surface is chamfered.

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