JPH0355005B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a snow accretion prevention type overhead power transmission line that prevents snow adhering to the surface of electric wires from accumulating and developing into a cylindrical shape. .

(Prior art and its problems) When snow adheres to the surface of a power transmission line made of stranded conductors during snowfall, this snow gradually develops and eventually accumulates in a cylindrical shape around the outer periphery of the wire.

The cause of such cylindrical accumulation of snow can be found in the structure of the power transmission line.

In other words, since power transmission lines have a stranded structure,
Relative movement is possible between the strands forming each layer of twisted wire and between the inner and outer twisted wire layers, so that the overall structure has low torsional rigidity.

If we consider the case in which a power transmission line with low torsional rigidity is under snowfall conditions in Figure 4, snow S1 has adhered to a part of the surface of the power transmission line W, as shown in Figure A, and this has grown to a certain extent. When the snow builds up to the point where it is, it becomes an eccentric load, and the electric wire W, which has low torsional rigidity, receives a rotation moment and is twisted and rotated in its own circumferential direction as shown by the arrow (A), and the position of the snow accretion S1 becomes as shown in Figure 4B. Change. Then, new snow S2 adheres to the area on the outer periphery of the electric wire W that was previously occupied by snow S1, as shown in FIG. Thereafter, similar actions are repeated as shown in FIGS. 4C to 4E, and finally snow S1 to S5 is deposited on the outer periphery of the electric wire W in a cylindrical shape.

As mentioned above, this cylindrical accumulation of snow is largely due to the low torsional rigidity of power transmission lines.For this reason, conventional methods have been used to prevent power lines from accumulating snow by attaching heavy plows to power transmission lines. Techniques for preventing twisting and rotation have been provided (Utility Model Application No. 59-28233, Utility Model Application No. 59-28234, etc.), but in this case,
There is a risk of fatigue due to stress concentration on the wires at the heavy thong attachment point, and accidents such as heavy thongs falling off, so the railway lines must be inspected rigorously, which significantly increases the burden of maintenance work and causes substantial damage. The increase in the weight of the wires causes an increase in the tension required to maintain the wires at a predetermined sag, which leads to problems such as the need to make structures such as steel towers more solid.

(Object of the invention) The present invention aims to reduce the increase in the weight of electric wires as much as possible.
The object of the present invention is to provide a snow-preventing overhead power transmission line that prevents snow from accumulating in a cylindrical shape by increasing the torsional rigidity of the wire.

(Structure of the Invention) The present invention increases the friction coefficient of the strands constituting the stranded conductor, and applies a tightening force to the outer periphery of the stranded conductor so that each strand is pressed against each other. It is what it is.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a first embodiment of the snow accumulation prevention type overhead power transmission line according to the present invention, in which the power transmission line W A stranded conductor constituting the power transmission line W is formed, and on the outer periphery of the outermost layer stranded conductor constituting the power transmission line W, an open helical wire material having a spiral inner diameter smaller than the outer diameter of the outermost layer stranded conductor is formed. A tightening body 1A is wound around the wires, and a tightening force is applied to press the wires against each other.

Therefore, the coefficient of friction of the surface of the strands with the rough surface increases, and the clamping force of the clamping body 1A causes the strands forming the stranded conductor to be strongly pressed against each other. By doing so, the relative movement between the strands and the twisted wire layers is significantly restrained compared to the past, and the power transmission line W is substantially integrated, resulting in a significant increase in torsional rigidity (polar moment of inertia). be. Therefore, the surface of the power transmission line W is
Even if snow S as shown in FIG. 2 occurs, the power transmission line W does not twist and rotate in its own circumferential direction, and the development of the snow S into a cylindrical pile is prevented.

FIG. 2 shows a second embodiment of the present invention, in which a tightening body 1B is used, which is formed from a strip material with a flat cross section into an open helical shape. This tightening body 1B
Since the contact area with the wire becomes larger, the range directly affected by the tightening force can be expanded accordingly.

FIG. 3 shows a third embodiment of the present invention, in which a tightening body 1C is composed of a fixed adapter 2 and a cylindrical wire net 3, and the fixed adapter 2 applies a tensile force to the cylindrical wire net 3. is applied to tighten the outer periphery of the power transmission line W, and the strands forming the stranded conductor are strongly pressed against each other. Therefore, according to this tightening body 1C, a tightening force can be applied to the entire outer periphery of the power transmission line W.

In addition, in the present invention, it is not necessary that all the strands have a rough surface with a large coefficient of friction;
The object may be selected as appropriate depending on the required torsional rigidity.

(Effects of the Invention) According to the present invention, the surface of the strands constituting the stranded conductor of a power transmission line is roughened to increase its friction coefficient, and the outer periphery of the stranded conductor is tightened with a tightening body. Since the wires are pressed against each other by using a heavy plow, the torsional rigidity of the entire power transmission line is significantly increased and the cylindrical accumulation of snow is reduced without increasing the weight of the wires, which is the case with conventional heavy plow installations. This can be effectively prevented.

[Brief explanation of drawings]

1 to 3 are perspective views showing first to third embodiments of the snow accumulation prevention type overhead power transmission line according to the present invention, and FIG. 4 shows snow adhering to the power transmission line accumulating in a cylindrical shape. FIG. W...Power line, S...Snowing, 1A, 1B, 1C
...Tightening body.

Claims (1)

[Claims] 1 The surface of the strands constituting the stranded conductor of the power transmission line is made into a rough surface with a large coefficient of friction, and the outer periphery of the stranded conductor is tightened with a tightening body, so that each of the stranded conductors constituting the stranded conductor is A snow-prevention type overhead power transmission line characterized by having wires pressed together.