JPH0433082B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a snow-accumulation-preventing electric wire that prevents snow from accumulating during snowfall. It concerns electric wires.

[Prior Art] A snow-accumulation prevention electric wire that prevents snow from accumulating on an installed power transmission line during snowfall has conventionally been of the type shown in FIG. 4. That is, as shown in FIGS. 4A and 4B, for an electric wire 1 in which a central conductor 2 is covered with an insulating sheath 3, fin-like protrusions 4 are provided at symmetrical positions on the outer peripheral surface of the insulating sheath 3. , 4 are formed parallel to the longitudinal direction along the central axis.

[Problems to be Solved by the Invention] By the way, in the conventional snow accumulation prevention electric wire configured as described above, when it is installed,
If the cable is installed over a short span, the fin-shaped protrusions 4, 4 can be kept in a straight line if the cable is installed with care, but if the cable is installed over a long span, the electric wire 1 will be twisted. The fin-like protrusions 4,4 are also twisted, and as shown in Figure 6, it appears as if spiral-shaped protrusions 4', 4' with long pitches have been formed. When this happens, the snow adhering to the top or side surface of the electric wire 1 rotates along the twisted protruding fins 4', 4'. In addition, in the case of a long span, the electric wire 1 will be affected by its own weight as shown in Fig. 5.
When the electric wire 1 installed on the utility pole 6 is bent, the overhead wire 5 becomes slanted due to the slack in the central part.
Due to this inclination, the snow starts to move laterally, and together with the spiral fins 4' and 4' mentioned above, it causes rotation, and due to this rotation, the snow grows into a tube of snow and becomes heavier. This has the disadvantage that the weight of the snow increases the weight of the snow and eventually causes the wire to break.

Furthermore, in conventional electric wires of this kind, line spacers are provided between the overhead wires, or dampers are installed on each overhead wire in order to prevent the wires from twisting due to the unbalance of their own weight caused by snow accumulation. However, this has the disadvantage that the cost of track construction increases significantly.

Furthermore, in order to solve the drawbacks of the conventional electric wire shown in FIG. something is proposed. (Refer to Utility Model Publication No. 52-40057.) However, this product has a problem in that it is difficult to extrude it continuously and efficiently due to the presence of the stop ring.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a snow-accumulation-preventing electric wire that eliminates the drawbacks of the conventional snow-accumulation-preventing electric wire described above and improves the snow-accumulation prevention effect.

[Means and effects for solving the problem] The present invention has a fin-like protrusion formed on the outer circumferential surface of an insulating sheath of an electric wire, which is connected to a linear portion parallel to the longitudinal direction along the central axis. It is formed of a protrusion having a steeply sloped portion that forms an angle of at least 45° or less with respect to a cross section perpendicular to the central axis, and lateral movement of snow is prevented by the steeply sloped portion.

[Examples] The present invention will be described below with reference to illustrated examples. FIG. 1 shows a first embodiment of the present invention, in which a snow-preventing electric wire 11 has a snow-accumulation-preventing electric wire 11 having a snow-accumulation-preventing electric wire 11 on the outer circumferential surface of its insulating sheath 13, which is parallel to the longitudinal direction along the central axis and constant. A linear portion 14a whose position is shifted in the circumferential direction for each length, and a steep slope that connects the linear portions 14a and forms an acute angle θ with respect to a cross section perpendicular to the central axis. A series of fin ray protrusions 14 consisting of portions 14a are formed at symmetrical positions.

Normally, in a snow-preventing electric wire, the fin-like protrusions are formed in a straight line parallel to the central axis, as described in detail in the conventional example above, but in the present invention, the fin-like protrusions are formed at steep angles at regular intervals. ing. By forming the fin-like protrusions 14 in this way, the lateral movement of snow can be prevented in the steeply sloped portion 1.
Blocked by 4b. That is, the steeply sloped portion 14b acts as a blocking wall, and therefore, the snow that is prevented from moving laterally falls when its weight exceeds the adhesive force with the outer peripheral surface of the electric wire 11, improving the snow accretion prevention effect.

Furthermore, the formation angle θ of the fin-like protrusions of the steeply inclined portion 14b is set relative to the cross section perpendicular to the central axis.
A angle of 45° or less is desirable to prevent lateral movement of snow.
Very good results have been obtained.

FIG. 2 shows a second embodiment of the invention. In the first embodiment (see FIG. 1), the steeply inclined portion 14b of the fin-like protrusion 14 is formed so as to repeatedly rotate in the right and left directions with respect to the circumferential surface of the insulating coating 13. , this second
In the embodiment, the steeply inclined portions 15b of the fin-like protrusions 15 having the straight portions 15a are wound around the outer peripheral surface of the insulating sheath 13 of the electric wire 11 in one direction, that is, by rotation in the same direction. is formed. Even if the steeply sloped portion 15b is formed in this way, it goes without saying that the same snow accretion prevention effect as in the first embodiment can be achieved.

FIG. 3 shows a third embodiment of the present invention, in which a straight section 16a is connected to a next straight section 16a by a steeply sloped section 16b.
It is formed at an angle of 90° with respect to the In the above first and second embodiments, the steeply sloped portion 1
Straight section 14 connected by 4b, 15b
Although the formation positions of a and 15a were 180 degrees out of phase on the circumferential surface of the insulating cover 13, in this third embodiment, they are connected at a steeply inclined portion 16b of the fin-like protrusion 16. The straight portions 16a are formed with angles shifted by 90°. Needless to say, even with this configuration, the snow accretion prevention effect is performed in exactly the same way as in the first embodiment.

Further, as in the third embodiment, the formation position of the linear portion 16a on the circumferential surface of the electric wire 11 is set at 45°.
It is optional to change the angular position such as or 90 degrees, or to increase the number of protrusions to two or more, and design changes are free as long as they do not depart from the spirit of the present invention. .

[Effects of the Invention] As described above, according to the present invention, snow adhering to electric wires is prevented from moving laterally at the steeply sloped portion and falls, so it does not become a pipe of snow as in the case of conventional methods. Therefore, disconnection due to snow can be prevented, and the drawbacks of this kind of conventional snow-preventing electric wire can be successfully solved. Particularly when constructing long-span electric wires, this method has a remarkable effect in that the work can be carried out without paying attention to the position of the linear fins, and the structure is simple, making it easy to manufacture.

In addition, snow is prevented from accumulating on the electric wires, and there is no need to worry about twisting of the electric wires due to unbalanced weight due to snow accretion. Significant cost reductions can be expected when constructing railway lines.

Further, the electric wire as a whole has a spiral fin-like protrusion when approximated, and therefore has the effect of preventing snow accumulation and wind noise.

Furthermore, unlike the one in Utility Model Publication No. 52-40057,
Since the fin-like protrusions are continuous in the longitudinal direction of the entire electric wire, they can be extruded continuously and efficiently.

[Brief explanation of drawings]

FIG. 1 is a side view of a snow-accumulation prevention electric wire showing a first embodiment of the present invention, and FIGS. 2 and 3 are side views showing second and third embodiments of the present invention, respectively.
4A and 4B are a front view and a side view showing an example of a conventional snow accumulation prevention electric wire, FIG. 5 is a perspective view showing how the snow accumulation prevention electric wire is used, and FIG. FIG. 6 is a partially enlarged perspective view of the snow-accumulation prevention type electric wire of FIG. 5 in a usage state. 1, 11... Snow accretion prevention electric wire, 3, 13... Insulating coating, 4, 14, 15, 16... Fin-shaped protrusion, 14a, 15a, 16a... Straight portion, 1
4b, 15, b, 16b...steep slope part, θ...
twist angle.

Claims (1)

[Claims] 1. Linear portions 14a, 15a, 16a that are parallel to the longitudinal direction along the central axis and whose positions are shifted in the circumferential direction by a predetermined length, and between these linear portions 14a, 15a, 16a. A series of fin-like protrusions are formed on the outer circumferential surface of the insulating cover 13 and have steeply sloped portions 14b, 15b, and 16b that connect to each other and form acute angles with respect to the cross section perpendicular to the central axis. Snow-prevention electric wire.