JPH07322457A - Thawing cable - Google Patents

Abstract

PURPOSE:To provide a thawing cable which has thawing effect high even at low current application and in which excessive temperature rise can be suppressed and for which aerial wiring can be performed easily. CONSTITUTION:This is one where a magnetic wire 6 is wound in spiral shape around an aerial line 5, and here the slippage of the magnetic wire 6 at passage of a metallic wheel is prevented by interposing a spacer 7 of aluminum line material in the space of the magnetic wire, and thawing effect is raised, using the magnetic wire 6 high in heat generation of eddy currents in the low magnetic field for the magnetic wire 6, and excessive heat generation in the high magnetic field of the magnetic wire 6 is suppressed by fin cooling effect of the magnetic wire 6 projecting from the spacer 7, and electrolytic corrosion with the aerial line 5 is prevented by covering the magnetic wire 6 with an Al layer 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed so that a magnetic wire is wound around an aluminum overhead wire, and the eddy current generated in the magnetic wire and heat generated by hysteresis loss are used to solve snow and ice formation on the aluminum overhead wire. The snow-melting wire has a high snow-melting effect even when a low current is applied, an excessive temperature rise is suppressed, and overhead wire construction can be easily performed.

[0002]

2. Description of the Related Art When snow or ice adheres to an overhead wire, the snow or ice develops while rotating along the twist groove of the overhead wire, and finally becomes a huge snow cube or a block of ice. As a result, a large load is applied to the overhead wire, which leads to the disconnection of the overhead wire and the collapse of the tower. As a countermeasure against this, multiple snow-drinking rings are attached to the outer circumference of the overhead wire at intervals so that snow and ice that rotate along the twist groove are stopped by this snow-draining ring and fall before becoming huge. The method of making was put to practical use. However, with this method, there is a problem that a vinyl house, an automobile, or the like located directly under the overhead electric wire is damaged by falling snow or falling ice. Therefore, a magnetic wire is wound around the overhead wire, and an eddy current and hysteresis loss are generated in the magnetic wire due to the alternating magnetic field of the alternating current flowing through the overhead wire, and the heat generated at that time causes the snow and ice to form on the overhead wire. A method of removing the residue has been proposed (JP-A-58-44609).

[0003]

In the snow melting wire wound with the magnetic wire, heat is generated due to eddy current or history loss of the magnetic wire during the daytime when the amount of power transmission is large (hereinafter abbreviated as eddy current heat generation).
However, due to the resistance heat of the overhead wire itself, it is difficult for snow and ice to occur, but conversely, there was a situation in which the overhead wire had to rise above the permissible temperature to reduce the amount of power transmission. .
In order to solve this situation, the composition of the magnetic wire was changed to lower the Curie temperature so that eddy current heat generation did not occur above a certain temperature.However, a magnetic wire with a low Curie temperature generally has a magnetic flux density in a low magnetic field. However, eddy current heat generation was not obtained when the power transmission was low and the amount of power transmission was low in the early morning. Further, depending on the magnetic wire, electrolytic corrosion occurs between the overhead wire and the overhead wire, and the cross-sectional area of the overhead wire is substantially reduced. In addition, the magnetic wire wound around the overhead wire shifts when the overhead wire is passed through the gold wheel,
There was a problem that the initial snow-melting effect could not be obtained due to the variation of the interval. The method of attaching the preformed magnetic wire after the overhead wire required a great deal of work for construction.

[0004]

The present invention has been earnestly studied in such a situation. The purpose of the present invention is to generate sufficient heat even when the amount of power transmission is small, and An object of the present invention is to provide a snow-melting wire that can quickly thaw ice, generate no excessive heat when a large amount of power is transmitted, do not cause electrolytic corrosion, and can easily perform overhead wire construction. That is, the invention of claim 1 is
In a snow-melting electric wire in which a magnetic wire is spirally wound on the outermost layer of an aluminum overhead wire, the magnetic wire has a Ni content of 40 to 60 wt.
%, And the balance is Fe, and the magnetic wire is coated with an aluminum material to a thickness of 10 to 60 μm.
In the gap between the spirally wound aluminum material-coated magnetic wire rods, the aluminum wire rod is wound as a spacer that keeps the gap between the aluminum material-covered magnetic wire rods constant, and the aluminum material-covered magnetic wire rod is It is characterized in that it is projected from the aluminum wire winding body.

The invention of claim 1 is a snow-melting electric wire in which a magnetic wire is spirally wound around an overhead wire, and a gap between the magnetic wires is prevented by a spacer between the magnetic wires to prevent the magnetic wires from slipping when passing through a gold wheel. A magnetic wire with large eddy current heat generation in a low magnetic field is used as the wire to enhance the snow melting effect, and excessive heat generation in a high magnetic field of the magnetic wire is suppressed by the fin cooling effect by winding the magnetic wire above the spacer to wind it. The magnetic wire is coated with an aluminum material to prevent electrolytic corrosion with the overhead wire.

An alternating magnetic field is generated in the overhead wire by an alternating current flowing therethrough, and the alternating magnetic field causes eddy current loss and hysteresis loss in the magnetic wire wound around the overhead wire to heat the magnetic wire. This heat generation amount depends on the saturation magnetic flux density and magnetic permeability of the magnetic wire. Most of the loss in the magnetic wire when an alternating magnetic field is applied in the axial direction of the soft magnetic wire having a circular cross section is eddy current loss. This eddy current loss is proportional to the square of the magnetic flux density under a low magnetic field, and is proportional to the 1.6th power of the magnetic flux density under a high magnetic field. In any case, the higher the saturation magnetic flux density, the larger the amount of heat generation. Pure iron, for example, has a saturation magnetic flux density of 22,000 G and generates a large amount of heat in a high magnetic field, but not so much in a low magnetic field. A magnetic wire having a high magnetic flux density in a low magnetic field and a large amount of heat generation is preferable for the snow-melting electric wire, and in the present invention, Fe-N satisfying the above condition is satisfied.
Focusing on i-based magnetic alloys. The saturation magnetic flux density of Fe is 22000 G as described above. When Ni is added to this Fe, the saturation magnetic flux density becomes the minimum at 4000 G at 30% Ni,
When Ni exceeds 30%, the saturation magnetic flux density becomes high again, and N
The maximum value is shown at i45wt%. The magnetic permeability shows a maximum at Ni 78%. The Fe-Ni alloy having Ni of 40 to 60 wt% has a high saturation magnetic flux density of 14,000 G or more in a low magnetic field and a relatively high magnetic permeability. Therefore, it is advantageous as a magnetic wire for a snow melting wire. Therefore, in the present invention, Ni is added to 40
An alloy magnetic wire containing -60% by weight and the balance Fe was selected. The reason for limiting the Ni content to 40-60 wt% is that Ni is
If it is less than 40 wt%, the magnetic permeability and the magnetic flux density in a low magnetic field decrease,
This is because if the Ni content exceeds 60 wt%, the magnetic flux density in a low magnetic field will decrease, and the heat generation amount required for snow melting cannot be obtained in any case.

In the first aspect of the invention, the aluminum material covering the magnetic wire material prevents electrolytic corrosion due to the potential difference with the overhead wire (aluminum conductor). When the magnetic wire is coated with an aluminum material, in a low magnetic field in which the magnetic flux is not saturated, the magnetic flux of the magnetic wire is shielded by the eddy current that tries to cancel the external magnetic field flowing in the aluminum coating layer, and the amount of heat generation is reduced.
In a high magnetic field in which the magnetic flux is saturated, the amount of heat generated conversely increases due to the eddy current flowing in the magnetic wire and the aluminum coating layer. Therefore, if a magnetic material having a high saturation magnetic flux density and a high squareness ratio is used for the magnetic wire, the amount of heat generated in a low magnetic field can be increased even when the aluminum material is coated.

In the invention of claim 1, the aluminum material is
Pure aluminum or aluminum alloy is applied. In order to coat the magnetic wire with the aluminum material, any method such as a melt dipping method, an electroplating method, or an aluminum tube adhering method in which the magnetic wire is covered with an aluminum tube and drawn is used. Aluminum coating thickness is 10 μm
If it is less than 60 μm, a sufficient anticorrosion effect cannot be obtained, and if it exceeds 60 μm, when Fe-40 to 60 wt% Ni alloy is used for the magnetic wire,
The amount of generated eddy current is reduced. Further, it is difficult to coat an aluminum material with a thickness of more than 60 μm by the melt dipping method. In the electroplating method, when the plating thickness exceeds 60 μm, the plating surface becomes rough, and the effect of improving heat generation by the aluminum coating is reduced.
Therefore, surface polishing becomes necessary and the cost becomes high. Therefore, the coating thickness of the aluminum material is preferably 10 to 60 μm.

In the invention of claim 1, the aluminum wire wound around the gap between the spirally wound magnetic wires plays a role as a spacer for keeping the space between the aluminum-coated magnetic wires constant, and the aerial wire is used. The magnetic wire is prevented from being displaced when passing through the metal wheel, and its shape is arbitrary such as circular or rectangular in cross section. The aluminum wire rod projects the aluminum wire-covered magnetic wire rod from the aluminum wire rod winding body so as not to interfere with the fin cooling effect of the magnetic wire rod. By doing so, the heat generation of the magnetic wire at the time of the maximum allowable energization is removed by the fin cooling effect of itself, and does not rise above the temperature of the overhead wire on which the magnetic wire is not wound. The aluminum wire for the spacer is lined up with the magnetic wire and wound together on the overhead wire.

According to a second aspect of the present invention, in a snow-melting electric wire in which a magnetic wire is spirally wound around the outermost layer of an overhead aluminum wire, the magnetic wire contains an alloy magnetic containing 40 to 60 wt% of Ni and the balance Fe. It is a wire rod, and the magnetic wire rod contains 10 to 10 zinc.
It is coated with a thickness of 60 μm, and the aluminum wire is wound in the gap between the spirally wound aluminum-coated magnetic wires as a spacer that keeps the gap between the aluminum-coated magnetic wires constant. The aluminum wire-covered magnetic wire rod projects from the aluminum wire rod winding body.

The magnetic wire wound around the snow-melting electric wire according to the invention of claim 1 and claim 2 contains F containing 40 to 60 wt% of Ni.
It is an e-Ni alloy. As described above, this alloy has a high saturation magnetic flux density of 14,000 G or more in a low magnetic field and a relatively high magnetic permeability. Therefore, it is useful as a magnetic wire for a snow melting wire. However, the present inventors have found that Ni is added to Fe in an amount of 3 to 78 wt.
% Alloy has a positive magnetostriction, and when tensile stress is left in this magnetic wire, magnetic properties are improved and the amount of heat generated is found to be improved. We have succeeded in improving the characteristics of the Ni-based magnetic wire.

That is, according to the invention of claim 3, in a snow-melting electric wire in which a magnetic wire is spirally wound around the outermost layer of an aluminum overhead wire, the magnetic wire is 3 to 28 wt% of Ni or 35 to 65 wt%.
%, Co 0 to less than 10 wt%, Al 0 to 9 wt%, Si 0 to 7.5 wt%, V 0 to 4 wt%, Cr 0 to 9 wt% and balance Fe, or Ni 3 ~ 65wt%, Co
10 wt% to 65 wt%, Al 0 to 9 wt%, Si 0 to 7.5
wt%, 0-4 wt% V, 0-9 wt% Cr, balance F
which is made of any one of the alloys consisting of e and has a thickness of 10 to 120 μm on the surface of the magnetic wire, Al, Al alloy, Zn, or Z.
It is a snow-melting electric wire characterized in that it is coated with any one of n alloys and is wound around the metal-coated magnetic wire so that tensile stress remains during power transmission.

According to the third aspect of the present invention, Ni is 3 to 28 wt% or 35 to 65 wt%, Co is less than 10 wt%, Al is 0 to 9 wt%,
0 to 7.5 wt% Si, 0 to 4 wt% V, 0 to 9 wt% Cr
% Alloy with the balance Fe, or 3-60 wt% Ni
%, Co 10 to 65 wt%, Al 0 to 9 wt%, Si 0 to
An alloy containing 7.5 wt%, 0 to 4 wt% V, 0 to 9 wt% Cr and the balance Fe is used for the magnetic wire.

The reason for limiting the alloying elements is as follows.
o is an alloying element that enhances the magnetic properties of the Fe-based material. In the former alloy, Co is less than 10 wt%, so Ni is 3 wt%.
When it is less than the above value, sufficient positive magnetostriction cannot be obtained, and even if tensile stress remains in the magnetic wire, the magnetic characteristics are not improved. Over 28wt%
If the amount is less than 35 wt% or exceeds 65 wt%, the magnetic flux density of the magnetic wire is reduced and the amount of heat required for snow melting cannot be obtained.
Further, in the latter alloy, since Co is contained in a large amount of 10 to 65 wt%, a magnetic flux density capable of obtaining a calorific value necessary for snow melting can be obtained even when the Ni content exceeds 28 wt% and less than 35 wt%.
Ni has good magnetic properties in a wide composition range of 3 to 65 wt%. Next, Al and Si have the effect of increasing the magnetic flux density. When their contents exceed 9 wt% and 7.5 wt%, respectively, the magnetic flux density decreases rather. V also improves cold workability. If the content exceeds 4 wt%, it becomes too hard,
On the contrary, the workability becomes worse. Further, Cr improves the corrosion resistance of the magnetic wire. If the content exceeds 9 wt%, the magnetic flux density of the magnetic wire decreases and it becomes impossible to obtain the amount of heat required for snow melting.

A snow melting electric wire according to a third aspect of the present invention is a snow melting electric wire in which a magnetic wire having the above alloy composition is coated with an aluminum material, and the aluminum coated magnetic wire is wound around an aluminum overhead wire so that tensile stress remains. . The aluminum material is coated in order to prevent electrolytic corrosion from occurring with the aluminum overhead wire. Further, the tensile stress is left in the magnetic wire because the magnetostriction of the magnetic wire of the present invention is positive, and when the tensile stress remains in the magnetic wire having a positive magnetostriction, the magnetic characteristics are improved and the heat generation amount is improved. Because of that. To retain tensile stress in the magnetic wire during power transmission, the magnetic wire can be welded to the overhead wire at a temperature below room temperature, brazed, or mechanically fixed. The method of winding and fixing it on the overhead wire can greatly improve the heat generation amount. Welding, brazing, or mechanical fixing may be performed only at both ends of the magnetic wire. By fixing the magnetic wire to the overhead wire, it is possible to prevent the magnetic wire from slipping when passing through the metal train without using a spacer.

The invention according to claim 4 is characterized in that the aluminum wire is used as a spacer in the gap between the magnetic wires wound in a spiral shape, and the aluminum wire is wound below the height of the metal-coated magnetic wire. It is a snow melting electric wire of the invention of description. Since there is no deviation of the magnetic wire when the snow-melting wire passes through the gold car and the magnetic wire projects from the aluminum wire, the fin cooling effect of the magnetic wire prevents an excessive temperature rise even when transmitting a large current.

According to a fifth aspect of the present invention, the aluminum wire is used as a spacer in the gap between the magnetic wires wound in a spiral shape, and the aluminum wire is wound at a height not more than half the height of the metal-coated magnetic wire. The snow melting electric wire according to any one of claims 1 to 4. Since more than half of the diameter of the aluminum-coated magnetic wire protrudes from the spacer (aluminum wire winding body), the fin cooling effect is increased and the allowable current at the maximum operating temperature can be increased.

The invention of claim 6 is characterized in that the cross section of the magnetic wire is rectangular, square, or fan-shaped.
To the snow melting electric wire according to claim 5. By making the cross-sectional shape of the magnetic wire rod rectangular, square, or fan-shaped, the contact area with the overhead wire becomes larger than that of an electric wire with a circular cross section,
The snow melting effect can be enhanced.

The invention of claim 7 is the snow melting wire according to any one of claims 1 to 6, characterized in that the magnetic wire or the magnetic wire and the spacer are wound around only a required portion of the overhead wire. Since the magnetic wire is wound only at the places where snow melting measures are required, not only energy loss but also installation cost can be reduced.

[0020]

According to the invention of claim 1, the aluminum-coated magnetic wire is spirally wound around the outermost layer of the aluminum overhead wire, and the aluminum wire is inserted in the gap between the spirally wound magnetic wires. Since the aluminum-coated magnetic wire is wound as a spacer that keeps the gap constant, the magnetic wire does not shift when passing through the gold wheel during an overhead wire, and a predetermined good snow melting effect can be obtained. The aluminum coated magnetic wire is
Since more than half of the diameter is projected from the aluminum wire winding body for the spacer, it is cooled by its own fin cooling effect, and the temperature rise due to eddy current heat generation is prevented. Since the magnetic wire is cooled by the fin cooling effect in this manner, a magnetic wire having a high Curie temperature can be used, and therefore, a magnetic wire having a high magnetic flux density in a low magnetic field can be selected. The fin cooling effect can be obtained by projecting the magnetic wire rod from the aluminum wire rod wound body for the spacer as much as possible. Further, since the magnetic wire is covered with the aluminum material, the magnetic wire does not cause electrolytic corrosion between the magnetic wire and the overhead wire. According to the second aspect of the invention, the magnetic wire is coated with the zinc material, and the same electrolytic corrosion preventing effect as in the case of coating the aluminum material can be obtained. As the zinc material, not only pure zinc but also zinc alloy can be applied.

The magnetic wire used in the invention of claim 3 is positive magnetostrictive, and this magnetic wire is used as the outermost layer of the aluminum overhead wire.
Since it is wound in a spiral shape so that tensile stress remains during power transmission, the magnetic characteristics of the magnetic wire are improved and the snow melting effect is improved. Since the magnetic wire is covered with the aluminum material, electrolytic corrosion with the overhead wire is prevented. If the magnetic wire is fixed to the overhead wire in order to retain tensile stress in the magnetic wire during power transmission, the magnetic wire is prevented from being displaced when passing through the railroad car. The displacement of the magnetic wire rods when passing through the gold wheel is also prevented by interposing a spacer between the magnetic wire rods. By protruding the magnetic wire from the spacer, the magnetic wire can have a fin cooling effect. The fin cooling effect of the magnetic wire can be further enhanced by projecting more than half of the height of the magnetic wire from the spacer.

As common to the snow melting electric wires of the first to third aspects, by making the cross section of the magnetic wire rod rectangular, square, or fan-shaped, the magnetic wire rod can be closely attached to the overhead wire. Also, by winding the magnetic wire only at the places where snow melting measures are required, energy loss and installation cost can be reduced.

[0023]

EXAMPLES The present invention will be described in detail below with reference to examples. (Example 1) A magnetic wire is wound around an overhead wire with an aluminum wire as a spacer interposed between the magnetic wires,
A snow melting wire was manufactured. For overhead cables, XTACI is made by twisting three layers of special heat-resistant aluminum alloy wire with a fan-shaped cross section into seven twisted wires of 4.4 mmφ Invar wire with 0.45 mm thick aluminum coating.
R650mm ² (Invar wire cross-sectional area 106mm ² , special heat-resistant aluminum alloy wire cross-sectional area 653.4mm ² , outer diameter 33.150mmφ) was used. This power transmission line can withstand the load even if 1 Kg of magnetic wire is wound around 1 m of the transmission line. The magnetic wire to be wound around the power transmission line includes pure iron and Fe-Ni alloy 7 shown in Table 1.
As a seed, a Fe-Ni-Cr-Si alloy type 1 was used. Pure aluminum, aluminum alloy, or zinc to the 9 types of magnetic wire,
The coating was performed by any one of the melt dipping method, the electroplating method, and the aluminum tube coating method. In the aluminum pipe deposition method, a magnetic wire of 10 mmφ is coated with an aluminum pipe, and the diameter of the magnetic wire is
The wire was drawn so as to have a diameter of 2.6 mm. The magnetic wire coated with this aluminum material or the like was spirally wound around the above-mentioned Invar-reinforced transmission line via a spacer. As the spacer, a special heat-resistant aluminum strip or wire was used. The outer diameter of the aluminum conductor part around which the spacer of the snow melting wire was wound was about 34.3 mmφ.

An embodiment of the obtained snow melting wire will be specifically described with reference to the drawings. 1A and 1B are a lateral sectional view and a side view, respectively, showing an embodiment of the snow melting electric wire of the present invention. On the outer circumference of the Invar stranded wire 3 of the Invar wire 2 coated with the Al layer 1,
A special heat-resistant aluminum alloy wire 4 having a fan-shaped cross section is twisted into three layers to form an overhead wire 5, and a magnetic wire 6 and a spacer 7 are twisted around the outer circumference of the overhead wire 5 at a ratio of 1 to 5. The magnetic wire 6 is wound so as to project from the spacer 7 and the fin cooling effect is maintained. The magnetic wire 6 is covered with an Al material layer 8 to prevent electrolytic corrosion.

Next, the manufacturing method of the magnetic wire is described in Fe-N.
The i-Cr-Si alloy will be described as an example. First, electrolytic iron having a purity of 99.9%, electrolytic nickel having a purity of 99.9%, electrolytic chromium having a purity of 99%, and silicon having a purity of 99.999% were used as raw materials, and each of them was mixed in a predetermined amount, vacuum-melted, and cast into an ingot. . Next, this ingot was soaked at 950 ° C for 48 hours, and then hot-rolled, drawn and wire-drawn to order 2.6.
Made a wire of mmφ. Next, this was annealed in hydrogen at 1050 ° C. for 3 hours and cooled in a furnace. 2.0 for other materials as well,
Processed into 2.6 or 4.0mmφ wire rod. The magnetic properties of these magnetic wires were measured. Among the magnetic characteristics, the saturation magnetic flux density and the Curie temperature were measured for a sample of 2.6 mmφ × 5 mm under a magnetic field intensity of 10 Oe using a vibrating sample magnetometer.
As for the magnetic flux density, a coil for magnetic flux detection of 25 turns is placed at the center of the excitation coil wound with 327 turns of enamel wire of 0.65 mmφ, and a 2.6 mmφ × 1000 mm magnetic wire is put in this detection coil. -Measured by H curve tracer. The magnetic field strength was changed to 40, 20 and 10 Oe. The results are shown in Table 1 together with the specific resistance at 0 ° C.

[0026]

[Table 1]

As is apparent from Table 1, the magnetic flux densities B ₁₀ at 10 Oe of the magnetic wire alloys a to e used in the snow melting electric wire of the present invention are the same as those of the comparative example products (No. f, g, h, i). It can be seen that the magnetic flux density is higher than that of the magnetic wire rod of the present invention, and the magnetic flux density B ₂₀ and B ₄₀ at 20 Oe and 40 Oe of the present invention have a small difference and good saturation characteristics of the magnetic flux density. The B ₁₀ of the present invention is nearly twice as high as the magnetic flux density of the alloy h used in the conventional snow melting wire.

The snow-melting wire wound with the magnetic wire was subjected to a salt spray test to investigate the corrosion resistance. Also, the amount of heat generated per 1 m of the power transmission line when the snow melting wire was energized with 91 A (electric wire surface magnetic field was 10 Oe) and the wire temperature when energized with the maximum allowable current of 2300 A were measured. The results are shown in Table 2.

[0029]

[Table 2]

As is clear from Table 2, the product of the present invention (N
Corrosion resistance of o.1 to 13) is 20% of the aluminum coating thickness of the magnetic wire.
If it is more than μm, it can withstand the salt spray test for 3000 hours. Even with 10 μm, it can withstand salt water spray for 2000 hours, causing no practical problem. The one using a magnetic wire rod electroplated with an Al-20 wt% Mn alloy (No. 4) also showed the same high corrosion resistance as when coated with pure aluminum.

The calorific value of the example products of the present invention (Nos. 1 to 14) when energized at 91 A is considerably higher than that of the comparative example products (Nos. 21 to 23). Although the magnetic fluxes a through e of the magnetic alloys a to e used in the snow melting wire of the present invention are lower than pure iron i by 5000 G or more, the calorific value of the snow melting wires of the present invention (No. 1 to 14) is that of pure iron. It is higher than the snow melting wire (No. 24) that uses magnetic wire because of its high B ₁₀ (magnetic flux density at 10 Oe). Ni content is 50wt%
At this time, the amount of heat generated at the time of energizing 91A becomes maximum. Ni is 40wt
% Or 60 wt% (No. 1, 9) had a slightly lower calorific value, but the calorific value necessary for partial snow melting was obtained. 5mm / hour
The calorific value required for complete snow melting is 15.9 w / m and the calorific value required for partial snow melting is 12.5 w / m.

The electric wire temperature of the example product of the present invention when energized at 2300 A is
It was below the temperature (No.25, 230 ℃) of the product without winding the magnetic wire. The magnetic wire rods used in the present invention each have a high Ni content and a high Curie temperature, and they generate a considerable amount of heat when energized at 2300 A, but the heat generation was suppressed by their own fin cooling effect. From this, it can be seen that even if the magnetic wire having a low Curie temperature is not used, the magnetic wire has a fin cooling effect, so that the temperature rise of the wire can be sufficiently suppressed under the maximum allowable current. Among the example products of the present invention, the wire temperature of No. 7 was 220 ° C, which was relatively high. This is because the thickness of the spacer strip was as thick as 1.0 mmφ, and the fin cooling effect of the magnetic wire rod was slightly reduced.
No. 12 uses a 1.0 mmφ wire rod for the spacer.
After all, it became a relatively high temperature of 218 ℃. Since the wire rod (No. 12) had more gaps, the heat was more likely to escape, and the temperature was slightly lower than that of the strip (No. 7).

Corrosion resistance of the comparative example is less than 2000 hours of salt spray, no plating (No. 16) and aluminum plating 5
Corrosion was observed on the thin one (μm) (No. 17).

The heat generation amount of the comparative example product when energized at 91 A is
18,20 to 24,25 was low. This is because, as is clear from Table 1, the magnetic flux density B _{10 of} the magnetic alloy used under a low magnetic field is low. No. 15 uses a magnetic alloy a having a small Ni content of 36%. This alloy a has a B content higher than that of B ₄₀ and B _{20.
The value of 10} drastically decreases, and the amount of heat generated when electricity is applied to 91 A is about half of that of the snow melting electric wire (No. 1 to 13) of the present invention. Ni content is 60%
The heat generation amount of No. 20 using the magnetic alloy b exceeding 10 is less than 12.5w / m, which is a heat generation amount to partially obtain the snow melting effect, and is not suitable for a snow melting electric wire.

The electric wire temperature of the comparative example product at the time of energizing 2300 A is N
o.19,24 exceeded the wire temperature of No.25, which does not wind the magnetic wire. In No. 19, the spacer thickness was more than half the diameter of the magnetic wire, and the fin cooling effect of the magnetic wire was not sufficiently obtained, and the temperature increased to 232 ° C. Nos. 2 and 4 use pure iron with a high Curie temperature, and the temperature at the permissible current is higher than the temperature rise of the wire (No. 25) without winding the magnetic wire. No.8
Has a Curie temperature of 600 ° C when the Ni content exceeds 60%.
As mentioned above, the temperature does not rise so much. This is because the amount of heat released by the fin cooling effect of the magnetic wire is greater than the amount of heat generated by the magnetic wire at the allowable current.

Next, the coating thickness of the aluminum material coating the magnetic wire will be described. Nos. 21 to 23 are snow-melting wires in which a wire material of magnetic alloy h with a high specific resistance of 120 μΩcm used in conventional snow-melting wires is coated with aluminum in various thicknesses. Maximum at 150 μm. On the other hand, Fe-50wt% Ni alloy with low specific resistance of 32μΩcm c
Snow wire made by winding magnetic wire of 5,10,20,60 and 80μm electroplated on the magnetic wire of No.17 (No.17,5,6,13,18)
The maximum amount of heat generated is 20 μm (No. 6), and the plating thickness is 80
When the thickness becomes thicker, the calorific value capable of melting snow cannot be obtained.
If the plating thickness is large, polishing is required after plating, resulting in high cost. Therefore, the optimum plating thickness is around 20 μm.

Looking at the effects of the aluminum coating method of the magnetic wire on the heat generation amount when the current is applied to 91A, the heat generation amount of the former is smaller than that of No. 3 (hot dipping) and No. 6 (electroplating). It is thought that hot-dip aluminum plating deteriorates the magnetic properties of the magnetic wire. Similarly, the influence of the wire diameter of the magnetic wire on the amount of heat generated when energizing 91A is No. 10 (2.0 mmφ), No. 6
Looking at (2.6 mmφ) and No. 11 (4.0 mmφ), it can be seen that the larger the wire diameter, the greater the amount of heat generation.

Example 2 A magnetic wire having an alloy composition shown in Table 3 was manufactured by the following method. 99.9% pure electrolytic iron,
99.9% electrolytic nickel, 99.5% cobalt, 99.9%
9% aluminum, 99% electrolytic chromium, 99.999% silicon, and 99.7% vanadium were used as raw materials, and each of them was mixed in a predetermined amount, vacuum melted, and cast into an ingot. Next, this ingot was soaked at 950 ° C. for 48 hours, and then hot-rolled, drawn, and wire-drawn were sequentially performed to form a 2.6 mmφ wire rod. Next, this was annealed in hydrogen at 1050 ° C. for 3 hours and cooled in a furnace. The magnetic characteristics of the obtained magnetic wire were measured. Among the magnetic characteristics, the saturation magnetic flux density and the Curie temperature are 2.6 mmφ ×
A 5 mm sample was measured with a vibrating sample magnetometer under a magnetic field strength of 10 kOe. As for the magnetic flux density, a coil for magnetic flux detection of 25 turns is placed at the center of the excitation coil wound with 327 turns of enamel wire of 0.65 mmφ, and a 2.6 mmφ × 1000 mm magnetic wire is put in this detection coil. -Measured by H curve tracer. The magnetic field strength was changed to 40 and 10 Oe.
The results are shown in Table 3 together with the specific resistance at 0 ° C.

[0039]

[Table 3]

As is clear from Table 3, there are high and low B ₁₀ (magnetic flux density at 10 Oe) of the magnetic alloy of the present invention. Alloy Nos. K, l, m, o, p and t have lower B ₁₀ than the conventionally used alloy No. h.

The magnetic wire shown in Table 3 was wound and fixed on an overhead wire by applying tension to the tensile strength of the magnetic wire to produce a snow melting wire. For the overhead wire, XTA is made by twisting 3 layers of special heat-resistant aluminum alloy wire with a fan-shaped cross section on 7 strands of 4.4 mmφ Invar wire coated with aluminum.
4.4mmφ Invar wire of CIR 650mm ² (Invar wire cross-sectional area 106mm ² , special heat-resistant aluminum alloy wire cross-sectional area 653.4mm ² , outer diameter 33.150mmφ) is thickened to 5.3mmφ, and the transmission line 1m
Even if a magnetic wire of 1 kg is wound, it is designed to withstand the load. A product in which an aluminum wire was interposed as a spacer between magnetic wires was also manufactured. Pure Al is used for the magnetic wire.
The coating was performed by any one of the melt dipping method, the electroplating method, and the aluminum tube coating method. In the aluminum tube deposition method, a 10 mmφ magnetic wire is coated with an Al pipe, and the diameter of the magnetic wire is 2.6 mm.
The wire was drawn to have a diameter of mmφ. As the spacer, a special heat-resistant aluminum strip or wire was used. The outer diameter of the aluminum conductor part around which the spacer of the snow melting wire was wound was about 34.3 mmφ.

The shape of the obtained snow melting electric wire is shown in FIG. 2A and FIG. 2B, respectively, though the magnetic wire is fixed to the overhead wire and no spacer is used. On the outer circumference of the Invar stranded wire 3 of the Invar wire 2 coated with the Al layer 1, a special heat-resistant aluminum alloy wire 4 having a fan-shaped cross section is twisted into three layers to form an overhead wire 5, and a magnetic wire is provided on the outer circumference of the overhead wire 5. 6 is wrapped around. The magnetic wire 6 is covered with an Al material layer 8 to prevent electrolytic corrosion. The overhead wire 5 and the magnetic wire 6 are seam welded. The shape using the spacer is the same as that in FIG.

The snow-melting wire wound with the magnetic wire was subjected to a salt spray test to investigate the corrosion resistance. Also, the amount of heat generated per 1 m of the power transmission line when the snow melting wire was energized with 91 A (electric wire surface magnetic field was 10 Oe) and the wire temperature when energized with the maximum allowable current of 2300 A were measured. The results are shown in Tables 4-5.

[0044]

[Table 4]

[0045]

[Table 5]

As is clear from Table 4, the product of the present invention (No.
26 to 45), the aluminum coating thickness of the magnetic wire was 20 μm or more, so that they could withstand a salt spray test for 3000 hours. Example product of the present invention
(No. 26 to 45), the heat generation amount when energizing 91 A is higher than that of the comparative example product (No. 43 to 61). As can be seen from the electric wire Nos. 34 to 36, the larger the residual tensile stress, the larger the amount of heat generation. In particular, the magnetic wire rods of alloys k, l, and m having a low B ₁₀ are used, and the comparative examples 47, 48 and 49 which do not retain tensile stress have low calorific value, but the tensile melting stress of the present invention (No. .
27,28,29) has significantly improved the calorific value. In other magnetic alloys of the present invention, the amount of heat generated is improved by applying tension. The amount of heat required for complete snow melting is 15.9 w / m and the amount of heat required for partial snow melting is 12.5 w / m when the amount of snowfall (precipitation conversion value) is 5 mm per hour.

The electric wire temperature of the example product of the present invention when energized at 2300 A is
It was below the temperature (No.61, 230 ℃) of the product without winding the magnetic wire. All of the magnetic wire rods used in the present invention have Curie temperatures higher than 230 ° C. except h, and they generate a considerable amount of heat when energized at 2300 A, but the heat generation was suppressed by their own fin cooling effect. From this, it can be seen that even if the magnetic wire having a low Curie temperature is not used, the magnetic wire has a fin cooling effect, so that the temperature rise of the wire can be sufficiently suppressed under the maximum allowable current. twenty three
The wire temperature at the time of energizing 00A is N
Compared with o.33,34, it is 213 ℃, which is relatively low. Among the spacers used, the temperature rise of No. 33, which has a large thickness, is large.

No. 31 and 32, in which the tensile stress remains, using the alloy n in which the iron of the Fe-50% Ni alloy is replaced by 3% Cr and 1% Si can obtain the perfect snow melting effect. When no tensile stress is retained, Table 5
No. 56,57, no partial snow melting effect can be obtained. The wire temperature rise of alloy n is relatively low, because the Curie temperature is low.

In the comparative example, a snow-melting electric wire (electric wire No.
In No. 8,59), since the Ni content deviated from the Ni content of the invention of claim 2, the calorific value capable of obtaining a sufficient snow melting effect was not obtained. Also, the amount of heat generated by the snow-melting wire (wire No. 60) in which tension was applied to the magnetic wire made of pure iron decreased, because the magnetostriction of pure iron was negative.

[0050]

[Effect] As described above, the snow melting wire of the present invention is obtained by spirally winding a magnetic wire around an overhead wire. Since the magnetic wire uses a magnetic wire with a large eddy current heat generation in a low magnetic field. It has a high snow-melting effect even when a low current is applied, and prevents deviation of the magnetic wire when passing through a gold wheel by interposing a spacer between the magnetic wires, and also prevents excessive heat generation of the magnetic wire in a high magnetic field. The fins are projected from the spacer to suppress the fins, and the magnetic wire is covered with an aluminum material to prevent electrolytic corrosion with the overhead wire. Also, by winding the magnetic wire around the overhead wire with residual tensile stress, the eddy current heat generation in the low magnetic field is improved, and the residual tensile stress is fixed to the overhead wire to pass the railcar. It prevents the magnetic wire from slipping. Therefore, it has a remarkable industrial effect.

[Brief description of drawings]

FIG. 1 is a cross-sectional view and a side view showing an embodiment of a snow melting electric wire of the present invention.

FIG. 2 is a cross-sectional view and a side view showing another embodiment of the snow melting electric wire of the present invention.

[Explanation of symbols]

 1 Al coating layer 2 Invar wire 3 Stranded aluminum-coated Invar wire 4 Special heat-resistant aluminum alloy wire with a fan-shaped cross section 5 Overhead electric wire 6 Magnetic wire rod 7 Spacer 8 Al material layer

Claims (7)

[Claims] 1. A snow melting wire in which a magnetic wire is spirally wound around the outermost layer of an aluminum overhead wire, wherein the magnetic wire is
An alloy magnetic wire rod containing Ni in an amount of 40 to 60 wt% and the balance being Fe, wherein the magnetic wire rod is coated with an aluminum material in a thickness of 10 to 60 μm, and the aluminum wire coated magnetic wire rod is wound in a spiral shape. An aluminum wire is wound around the gap as a spacer that holds the interval of the aluminum-coated magnetic wire constant, and the aluminum-coated magnetic wire projects from the aluminum wire wound body. A snow melting wire. 2. A snow melting electric wire in which a magnetic wire is spirally wound around the outermost layer of an aluminum overhead wire, wherein the magnetic wire is
An alloy magnetic wire rod containing Ni in an amount of 40 to 60 wt% and the balance being Fe, wherein the magnetic wire rod is coated with a zinc material in a thickness of 10 to 60 μm, and the spirally wound aluminum-coated magnetic wire rod is An aluminum wire is wound around the gap as a spacer that holds the interval of the aluminum-coated magnetic wire constant, and the aluminum-coated magnetic wire projects from the aluminum wire wound body. A snow melting wire. 3. A snow melting wire in which a magnetic wire is spirally wound around the outermost layer of an aluminum overhead wire, wherein the magnetic wire is
3 to 28 wt% or 35 to 65 wt% Ni, 0 to less than 10 wt% Co, 0 to 9 wt% Al, 0 to 7.5 wt% Si, 0 to V
4 wt%, an alloy containing 0-9 wt% Cr and the balance Fe, or 3-60 wt% Ni, 10 wt-65 wt% Co, A
1 to 0 to 9 wt%, Si to 0 to 7.5 wt%, V to 0 to 4 wt%
%, Cr in an amount of 0 to 9 wt% and the balance being Fe, and a metal of any one of Al, Al alloy, Zn, or Zn alloy having a thickness of 10 to 120 μm is formed on the surface of the magnetic wire. A snow-melting electric wire which is covered and wound around the metal-coated magnetic wire so that tensile stress remains during power transmission. 4. The snow melting electric wire according to claim 3, wherein the aluminum wire is used as a spacer in the gap between the spirally wound magnetic wires and wound below the height of the metal-coated magnetic wires. 5. The aluminum wire is used as a spacer in the gap between the spirally wound magnetic wire rods, and the aluminum wire rods are wound at a height not more than half the height of the metal-coated magnetic wire rods. To the snow melting electric wire according to claim 4. 6. The snow melting electric wire according to claim 1, wherein the magnetic wire has a rectangular, square, or fan-shaped cross section. 7. The snow melting electric wire according to claim 1, wherein a magnetic wire or a magnetic wire and a spacer are wound around only a required portion of the overhead wire.