JPH0119552Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improved snow-resistant electric wire.
Sleeves made of ferromagnetic material are attached to the outer circumference of the electric wire at appropriate intervals, and the ferromagnetic sleeve is heated by electromagnetic hysteresis due to electricity, and the heat melts and removes snow that has fallen on the wire. It is known about snow cables.

However, in this case, the ferromagnetic sleeve not only generates heat when it snows, but also constantly generates heat even when the temperature is high, unnecessarily increasing current loss and dissipating wasteful heat.

To solve this problem, it has been proposed to construct the sleeve in whole or in part from a material with a low Curie point so that it becomes magnetic only at temperatures below snowfall temperatures. However, this is an ideal theory, and it is difficult to find such a material, and even if it were found, the degree of magnetism would not be a desirable value, and the heat generation would not be as high as desired. is the current situation.

The present invention was devised in view of such circumstances, and its gist is that the sleeve is made of a bimetal made of a ferromagnetic material with slits, and that the slits are in contact with each other at snowfall temperatures. This is because the structure is such that they are spaced apart at temperatures higher than that.

This will be explained below based on the drawings.

FIG. 1 is a partial sketch of a snow-resistant electric wire according to the present invention, where 1 is an electric wire and 2 is a sleeve covered with the electric wire 1. The sleeve 2 has a slit 3, and is made of bimetal consisting of a low expansion side 2a and a high expansion side 2b, at least one of which is made of a ferromagnetic material, and the low expansion side 2b is made of a ferromagnetic material.
It is configured such that a is on the outside.

The gap between the slits 3 is adjusted as follows. That is, when the outside temperature becomes low, such as during snowfall, the sleeve 2 acts to reduce its diameter since the low expansion side 2a is on the outside, and the sleeves 3 come into contact as shown in Fig. 3, but once again. When the outside temperature begins to rise, the diameter of the sleeve 2 increases, and the gap 3 moves apart as shown in FIG. Adjustment to such a gap can be easily achieved by simple experiment or calculation.

If a large number of sleeves 2 constructed as described above are placed on the outer periphery of the wire at appropriate intervals, each sleeve 2 will form a single cylinder at snowy temperatures due to the slits 3 coming into contact with each other. ,
The ferromagnetic material forming the sleeve 2 generates heat.
However, if the outside temperature becomes high and the slits 3 are spaced apart, an electromagnetic insulating part is formed by the slits 3, so that no heat is generated. With this configuration, the heat generation is limited to only when it snows, so it is possible to prevent heat generation from occurring all the time as in the conventional case, and since the heating element itself is a normal ferromagnetic material, it is possible to expect necessary and sufficient heat generation. It is something.

[Brief explanation of the drawing]

FIG. 1 is a partial sketch of the snow-resistant electric wire according to the present invention, and FIGS. 2 and 3 are explanatory diagrams showing the behavior of the sleeve depending on the outside temperature. 1: Electric wire, 2: Sleeve, 2a: Low expansion side, 2
b: High expansion side, 3: Slit.

Claims (1)

[Scope of utility model registration request] In a snow-resistant electric wire in which a sleeve made of a ferromagnetic material is attached to the outer periphery of the wire, the sleeve has a cylindrical shape with a slit in the longitudinal direction, at least one side of which is made of a ferromagnetic material, with the low expansion side facing outward. A snow-resistant electric wire constructed of bimetal, the gaps between the slits being in contact at snowfall temperatures and separated at higher temperatures.