JP2895487B2 - Low wind noise overhead electric wire - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a low wind noise overhead electric wire that suppresses generation of wind noise.

[Prior Art] When wind blows on an installed electric wire, Karman vortices are generated behind the electric wire, and wind noise is generated. In order to prevent the wind noise, it is effective to disperse the Karman vortex by providing an uneven protrusion in the longitudinal direction on the outer periphery of the electric wire.

For this reason, in overhead wires such as ACSR, the outer diameter or cross-sectional shape of some strands in the outermost layer is made different from other strands in the same layer, and they are projected from the outer peripheral surface to form a helical projection in the longitudinal direction. The formed one is used. An example is shown in FIG. In this overhead electric wire, a plurality of steel wires 1 are twisted to form a steel stranded wire 2, and an aluminum wire 3 is twisted thereon to form a first aluminum wire layer 4. The second aluminum wire layer 6 is formed by twisting the aluminum wires 5, and a part of the aluminum wires 5A constituting the outermost layer, that is, the second aluminum wire layer 6, is formed. Is made larger than the other strands of the same layer and these strands 5A are adjacent to each other to project from the outer peripheral surface to form a projecting portion 7 spirally in the longitudinal direction. By forming the protruding portion 7 in this manner, Karman vortices are disturbed, and generation of wind noise can be prevented.

Although FIG. 5 is also a conventional low wind noise overhead electric wire, this electric wire is the same as the electric wire of FIG. 4 except that the outermost strands 5 and 5A are segmented.

[Problem] However, such an overhead electric wire, when it rains,
Rain water collects on the lower surface side of the electric wire, and large water droplets 8 are likely to be formed. When such water droplets 8 are formed, corona discharge is generated therefrom. This has the effect of preventing wind noise, but has the disadvantage of causing a new environmental problem called corona noise during light rain or for a while after rain stops (that is, when the background noise due to rainfall is small or disappears). is there.

Means for Solving the Problems and Actions The present invention provides an overhead electric wire that can prevent wind noise and also corona noise, and has a configuration in which the outer diameter or cross section of a part of the outermost wire is reduced. In the low wind noise overhead electric wire in which the shape is different from and adjacent to the other strands of the same layer and which is projected from the outer peripheral surface to form a projection in a spiral shape in the longitudinal direction, the element forming the projection is provided. A ridge is provided on the wire, a groove having a width of 3 mm or more is formed by these ridges, and the size of the groove is set to a size such that a water drop dripping from the lower surface of the electric wire grows in the groove. Things.

In this way, when rainwater adhering to the electric wire wraps around the lower surface of the wire along the projecting portion and falls as a water droplet from the lower surface of the wire of the projecting portion, the water droplet falls within the groove formed in the projecting portion. Since the water drops after growing, the water droplet does not largely protrude from the protruding portion, and the generation of corona noise due to corona discharge can be suppressed.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. In this low wind noise overhead electric wire, the configuration of the steel stranded wire 2 and the first aluminum wire layer 4 is the same as the conventional one, but is the outermost layer. The size of a part of the aluminum wire 5A of the second aluminum wire layer 6 is made larger than that of the other wires 5 to form the protrusion 7 and the protrusion 7
Are provided on the element wire forming the groove, and a concave groove 9 is formed by these ridges 7A, 7A.

In this embodiment, the groove 9 is formed by making the cross-sectional shape of the large-sized aluminum wire 5A substantially L-shaped and by adjoining two of them in a face-to-face relationship. The groove 9 is not limited to this, and the groove 9 can be formed even in a sectional shape as shown in FIG. 2 or FIG.

The width of the groove 9 was 3 mm or more so that the water droplet 8 did not protrude greatly from the protruding portion 7. The thickness of the ridges 7A on both sides of the groove 9 is 2 to 2 so as to prevent the portion from being crushed when passing through the wheel during overhead wiring work and to prevent water droplets from developing greatly at the portion. It is desirable to set it to about 3 mm.

[Effects of the Invention] As described above, the low wind noise overhead electric wire according to the present invention is configured such that a groove is formed in the projecting portion by a ridge provided on a wire forming a projecting portion for wind noise prevention. As a result, water droplets dripping from the wire lower surface side of the protrusion grow in the groove and do not largely protrude from the protrusion, so that there is an advantage that wind noise and corona noise can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the low wind noise overhead electric wire according to the present invention, and FIGS. 2 and 3 show other examples of the strand used for the low wind noise overhead electric wire of the present invention. FIG. 4 and FIG. 5 are cross-sectional views each showing a conventional low wind noise overhead electric wire. 1: steel strand, 2: steel strand, 4: first aluminum strand, 5: aluminum strand, 5A: large aluminum strand, 6: second aluminum strand, 7: protrusion , 7A: ridge, 8: water drop, 9: groove.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-59-221906 (JP, A) JP-A-59-98406 (JP, A) JP-A-60-149014 (JP, A) 170209 (JP, U) Japanese Utility Model Showa 57-159326 (JP, U)

Claims (1)

(57) [Claims] 1. A part of an outermost layer in which the outer diameter or cross-sectional shape is different from that of another element in the same layer and is adjacent to the outermost layer, so that the outermost layer is protruded from the outer peripheral surface and spirally protruded in the longitudinal direction. In the low wind noise overhead electric wire in which is formed, a ridge is provided on the element wire forming the protrusion, a groove having a width of 3 mm or more is formed by the ridge, and the size of the groove is dropped from the lower surface of the wire. A low wind noise overhead electric wire, characterized in that the size of the drop is such that water drops grow in the groove.