JPH1141768A - Magnetic heating composite wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic heating composite wire which can generate a sufficient amount of heat even when a low current flows through a transmission line. SOLUTION: A plurality of magnetic strands 1 each comprising a thin wire having diameter of 0.5 mm or less coated with an insulation film 2 are bundled into a bundle magnetic body 4. The bundle magnetic body' 4 is applied tightly with a coating 3 such that no air gap is formed. Since heat loss at the air gap is eliminated in the magnetic heating composite wire 10, eddy current is increased furthermore in the coating 3 and the amount of Joule's heat can be increased.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is arranged around transmission and distribution lines in order to prevent damage to the overhead transmission and distribution lines due to snow or icing, and generates heat due to a magnetic field generated around the transmission and distribution lines. The present invention relates to a magnetic exothermic composite wire that melts ice and snow attached to transmission and distribution lines by heat.

[0002]

2. Description of the Related Art In winter, snow or ice may form on overhead transmission lines in cold regions. When the icing snow grows, the wind pressure load increases and the tension of the electric wires becomes excessive, which may cause serious accidents such as disconnection of transmission and distribution lines or collapse of a steel tower. In addition, there is a possibility that the grown icing snow falls from the power transmission and distribution line and damages humans or crops. In order to prevent such damage, a magnetic heating composite wire that melts ice and snow using a magnetic field generated around transmission and distribution lines has been put to practical use.

Conventionally, a magnetic heating composite wire has a structure in which a core wire made of a ferromagnetic metal is covered with a coating material made of a conductive metal. The composite magnetic heating wire is disposed around the transmission and distribution line by a method such as winding around the transmission and distribution line. In this case, the magnetic flux generated around the power distribution line acts on the magnetic heating composite wire, causing iron loss in the ferromagnetic core wire and eddy current loss in the conductive metal coating material. I do. The ice and snow attached to the transmission and distribution lines are melted by the heat generated in the magnetic heating composite wire.

However, in this prior art,
When the surrounding magnetic field is weak, there is a problem that the amount of generated heat is reduced. The direction of the electromotive force induced by electromagnetic induction is
Lenz's law (Lenz's law) states that the magnetic flux generated by the current flowing in the direction is a direction that hinders the increase or decrease of the original magnetic flux.
According to s Low), an eddy current is generated in the ferromagnetic material due to a change in magnetic flux in the ferromagnetic material due to a change in current flowing through the transmission and distribution line. Then, the magnetization of the ferromagnetic material is hindered by the reverse magnetic field generated by the eddy current. For this reason, there is a problem that the change in the interlinkage magnetic flux in the conductive metal is reduced, the eddy current loss in the conductive metal is reduced, and the calorific value is extremely reduced.

[0005] As described above, the loss of the heat generation amount due to the reverse magnetic field is a serious problem when the heat generation amount is originally small because the current flowing through the transmission and distribution line is small, that is, the surrounding magnetic field is weak. However, since the snow damage of transmission and distribution lines occurs frequently in such areas where the electric current is small, there is a problem that the damage due to snow cannot be effectively avoided with the conventional magnetic heating composite wire. is there.

Accordingly, the present inventors have bundled a plurality of magnetic wires insulated and coated to form a bundled magnetic material, and coated a conductive coating around the bundled magnetic material, so that even on a low magnetic field side, A magnetic heating composite wire capable of obtaining a high calorific value has already been proposed and filed (Japanese Unexamined Patent Publication No. 2-1).
No. 32703). FIG. 2 is a sectional view showing the conventional magnetic heating composite wire. As shown in FIG. 2, in the conventional magnetic heating composite wire 11, the magnetic element wire 1 made of a magnetic metal or an alloy is processed into a fine line having a diameter of 0.5 mm or less. An insulating film 2 is coated on the peripheral surface of each of the magnetic wires 1, and a bundle magnetic body 4 is formed by bundling a plurality of the magnetic wires 1. The periphery of the bundle magnetic body 4 is covered with a covering 3 made of a conductive metal, preferably a good conductor metal or alloy. In the magnetic heating composite wire 11, a gap 5 is formed between the magnetic wires 1 and between the magnetic wire 1 and the covering 3.

[0007] The magnetic heating composite wire 11 constructed as described above.
In the above, the eddy current generated in the ferromagnetic material wire 1 is reduced as compared with the conventional device by forming the ferromagnetic material portion into a bundle of thin wires 1 having a diameter of 0.5 mm or less.
The magnetization of the magnetic wire 1 proceeds quickly and sharply. Therefore, the magnetic flux density trapped around the bundle magnetic body 4 increases, and the amount of change in the magnetic flux increases. Therefore, an eddy current generated in the coating 3 made of a conductive metal or an alloy coated around the bundle magnetic body 4 increases, so that the amount of heat generated by Joule loss increases.

[0008]

However, in the conventional magnetic heating composite wire 11 described in Japanese Patent Application Laid-Open No. 2-132703, a gap 5 is formed between the magnetic element wire 1 and the covering 3. As a result, Joule heat due to eddy current does not occur in the gap 5. For this reason, even if the eddy current generated in the magnetic element wire 1 is reduced to increase the magnetic flux density trapped around the bundle magnetic body 4, the loss of the heat generation due to the Joule heat occurs in the gap 5. In addition, the amount of heat generated by the magnetic heating composite wire cannot be sufficiently increased. For this reason, there is a problem that a sufficient amount of heat cannot be obtained when the current flowing through the electric wire current is small.

[0009] The present invention has been made in view of such a problem, and even when the current flowing through the transmission and distribution line is small,
It is an object of the present invention to provide a magnetic heating composite wire capable of obtaining a sufficient heat generation.

[0010]

According to the present invention, there is provided a magnetic heating composite wire comprising a plurality of magnetic wires each made of a ferromagnetic metal or alloy having a diameter of 0.5 mm or less and each of which has an insulating coating on its peripheral surface. It is characterized by having a bundle magnetic body formed by bundling and a cover made of a conductive metal or an alloy, which fills the outer surface irregularities of the bundle magnetic body and is covered without gaps.

In the present invention, by forming the ferromagnetic material portion into a bundle of magnetic wires having a diameter of 0.5 mm or less, eddy current generated in the magnetic wires is reduced,
Since the magnetization of the magnetic element wire proceeds promptly and sharply, the density of the magnetic flux trapped around the bundle magnetic body increases, and the amount of change in the magnetic flux increases. The periphery of the bundle magnetic body is covered with a covering made of a conductive metal or an alloy so as to fill the irregularities on the outer surface, and no gap is formed between the bundle magnetic body and the covering. . The voids that are not covered by the coating do not contribute to the increase in Joule heat due to eddy currents, and thus the formation of voids results in the loss of Joule heat increase due to eddy currents. However, in the present invention, since the coating is coated around the bundle magnetic material without forming a gap, the eddy current in the coating further increases, and the heat generation due to Joule heat may further increase. it can.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be specifically described with reference to the accompanying drawings. FIG. 1 is a cross-sectional view showing an example of a magnetic heating composite wire according to an embodiment of the present invention. In FIG. 1, the same components as those in FIG. 2 are denoted by the same reference numerals, and detailed description thereof will be omitted. In the present embodiment, the magnetic element wire 1 is processed into a fine line having a diameter of 0.5 mm or less, and the peripheral surface of each magnetic element wire 1 is covered with an insulating film 2 such as an oxide film. A bundle magnetic body 4 is formed by bundling a plurality of the magnetic wires 1. Around the bundle magnetic body 4, the cover 3 is covered without gaps so as to fill the irregularities on the outer surface of the bundle magnetic body 4.

The magnetic heating composite wire 10 constructed as described above
In this case, the amount of heat generated by Joule heat generated in the magnetic heating composite wire 10 can be further increased as compared with the conventional technique shown in FIG. That is, if a void is formed around the bundle magnetic body 4 as shown in FIG. 2, an increase in Joule heat due to an eddy current is lost, and therefore, as shown in FIG. Is covered with the cover without gaps, the eddy current in the cover 3 further increases, and the amount of heat generated by Joule heat can be further increased. Therefore, a sufficient amount of heat can be obtained even when the magnetic field strength is low.

FIG. 1 shows an example of the structure of a composite magnetic heating wire according to an embodiment of the present invention, and the sectional shape of the composite magnetic heating wire of the present invention is not limited to this. Absent.

[0015]

Next, a description will be given of a result of obtaining a heat generating composite wire according to an example of the present invention and calculating a calorific value thereof in comparison with a comparative example.

Example 1 As a magnetic substance, iron (Fe) was 58% by weight and nickel (N
i) is drawn by drawing an alloy having a composition of 42% by weight to a diameter of 0.1%.
mm was obtained. After performing an oxide film treatment on the wires to form an insulating film around the wires, 21 wires were bundled to form a bundle magnetic body. And this bundle magnetic material is made of aluminum corrugated pipe (hereinafter referred to as aluminum pipe).
To cover the periphery of the bundle magnetic body with an aluminum material. In this aluminum coating, the bundle magnetic material was inserted into an aluminum pipe, and drawn using a set die (pressure die) until the working ratio reached 40% (the working ratio calculated immediately after the insertion). . Then, a part of the aluminum pipe is pressed into the bundle magnetic body,
No void was formed around the bundle magnetic body, and the outer surface of the bundle magnetic body was densely covered with the aluminum material.

The magnetic heat-generating composite wire manufactured in this manner was used in this embodiment. Further, for comparison, a magnetic exothermic composite wire obtained by coating a single wire of an iron-nickel alloy having the above composition with an aluminum material was used as Comparative Example 1, and an insulating film was formed around a strand having the above composition. A magnetic heating composite wire in which 21 wires are bundled to form a bundle magnetic body, which is inserted into an aluminum pipe, and aluminum is coated around the bundle magnetic body without using a pressure die (that is, as shown in FIG. 2). Comparative Example 2). Then, these magnetic exothermic composite wires were placed in a magnetic field having a magnetic field strength shown in Table 1 below, and the heat generation per unit weight of each magnetic exothermic composite wire was examined. With respect to these results, the heat generation amount is shown in Table 1 below together with each magnetic field strength.

[0018]

[Table 1]

As shown in Table 1, in this example, the amount of heat generated for all magnetic field strengths was larger than that in the comparative example. On the other hand, in Comparative Example 1, the calorific value was small at all magnetic field intensities. In particular, when the magnetic field intensity was as low as 10 Oe, the calorific value was about 50% or less as compared with Example 1. Further, in Comparative Example 2, as compared with Comparative Example 1, a large amount of heat was generated at all magnetic field strengths. However, since voids were formed around the bundle magnetic body,
In comparison with the above, the calorific value was lower by about 10% at all magnetic field strengths. As mentioned above, snow damage to power transmission and distribution lines occurs frequently in areas where the electric current is low.Therefore, when the magnetic field strength is low, the large amount of heat generated by the magnetic heating composite wire is extremely important in preventing snow damage. It is informative.

EXAMPLE 2 97% by weight of iron (Fe) and 3% by weight of silicon (Si)
Was used as a magnetic material, and the magnetic material was drawn to obtain a wire having a diameter of 0.1 mm. The wires were coated with an epoxy resin having a decomposition temperature of 200 ° C. or higher to form an insulating film around the wires, and then 21 wires were bundled to form a bundle magnetic body. Then, an aluminum covering was coated around the bundle magnetic body by CM (conform method) to manufacture a magnetic heating composite wire.

The magnetic heat-generating composite wire manufactured in this manner was used in this example. For comparison, a magnetic heat-generating composite wire obtained by coating an aluminum material on a single wire of the iron-silicon alloy having the above composition was used as Comparative Example 3, and an insulating film was formed around the element wire having the above composition. A magnetic heating composite wire (ie, a magnetic heating composite wire as shown in FIG. 2) in which 21 strands were bundled to form a bundle magnetic body and an aluminum coating was coated around the bundle magnetic body was used as Comparative Example 4. Comparative Example 4
Was coated with an aluminum coating by a tube forming method.

Then, these magnetic exothermic composite wires were placed in a magnetic field having a magnetic field strength shown in Table 2 below, and the heat generation per unit weight of each magnetic exothermic composite wire was examined. With respect to these results, the heat generation amount is shown in Table 2 below together with each magnetic field strength.

[0023]

[Table 2]

As shown in Table 2, in this embodiment,
The calorific value for all magnetic field strengths was larger than in the comparative example. On the other hand, in Comparative Example 3, the calorific value was small at all the magnetic field strengths. In particular, when the magnetic field strength was as weak as 10 Oe, the calorific value was about 50% or less as compared with Example 1. Further, Comparative Example 2 showed a large amount of heat generation at all magnetic field strengths as compared with Comparative Example 1, but all voids were formed around the bundle magnetic body. The heat generation was as low as about 10% at the magnetic field strength of.

[0025]

As described above, in the magnetic heating composite wire according to the present invention, a plurality of magnetic wires each having a diameter of 0.5 mm or less insulated and coated are bundled to form a bundle magnetic material. The periphery of the body is covered with a conductive covering in close contact, and no gap is formed between the bundle magnetic body and the covering. Therefore, a sufficiently high heat value can be obtained even on the low magnetic field side. Thereby, the magnetic composite wire according to the present invention can obtain a sufficiently high calorific value even in a transmission and distribution line having a low electric wire current, and can melt snow in such an area, thereby effectively reducing damage caused by snow accretion. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a magnetic heating composite wire according to the present invention.

FIG. 2 is a cross-sectional view showing a conventional magnetic heating composite wire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1; Magnetic element wire 2; Insulating film 3; Conductive covering 4; Bundle magnetic body 5; Void section 10, 11;

Claims (1)

[Claims] 1. A bundle magnetic body having a diameter of 0.5 mm or less and a plurality of magnetic wires made of a ferromagnetic metal or alloy whose respective peripheral surfaces are insulated and coated, and
A magnetic heat-generating composite wire comprising: a conductive metal or alloy covering the outer surface of the bundle magnetic material so as to cover the outer surface unevenness and to be covered without gaps.