JPH0210647B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a magnetic ring for melting snow that is attached to electric wires, mainly to prevent wire breakage accidents and collapse of steel towers due to snow accumulation on electric wires.

In general, snow accretion on electric wires occurs when the wire temperature drops below 3°C. ), Permendial (49%
A magnetic ring such as Co-2% V-Fe) is attached to an electric wire, and the large magnetic hysteresis loss of 10,000 erg cm ^-3 or more of the ring actively generates heat to melt snow. Since snow moves along the twisting direction of the wires before it falls from the wires, it is not necessary to cover the entire length of the wires with magnetic snow-melting rings. For example, simply attaching the rings at intervals of about 50 cm will have no effect. However, the ring with high saturation magnetic flux density has a high Curie temperature of 400°C or higher,
Even in the summer when there is no snowfall, there is a problem in that heat generation results in loss of transmitted power. Therefore, Fe-Ni is placed at one or two locations in the magnetization direction of the ring, that is, in the circumferential direction.
It has been proposed that a low Curie temperature ferromagnetic metal alloy (hereinafter referred to as a low Curie temperature material) having a Curie temperature of 0 to 150°C, such as Fe-Ni-Cr or Ni-Cu alloy, is inserted as a temperature switch in a magnetic circuit. There is. At low temperatures below the Curie temperature, the inserted low Curie temperature material becomes ferromagnetic, creating a magnetic circuit of the composite ring consisting of a high saturation magnetic flux material (hereinafter referred to as "high saturation magnetic flux material") and a low Curie temperature material. When closed, heat is generated due to the magnetic history loss of the composite ring, but at high temperatures above the Curie temperature, the inserted low Curie temperature material becomes a low magnetic flux density or non-magnetic material, forming a magnetic gap in the composite ring. Magnetic hysteresis loss is reduced and heat generation is suppressed. In this way, the composite ring can suppress heat generation at low temperatures and heat generation at high temperatures, and exhibits effective performance for snow melting.

The present invention relates to a method of manufacturing such an effective composite ring at a low cost.

Hereinafter, the present invention will be explained with reference to drawings listed as examples.

In Figure 1, the magnetic hysteresis loss is 10000erg・cm
^-3 or higher, iron, steel with a Curie temperature of 400℃ or higher,
A ferromagnetic metal alloy strip 1 such as silicon steel, 45% Ni-Fe permalloy, permendile, etc. and a low Curie temperature material 2 having a Curie temperature of 0°C to 150°C are welded in the width direction to form a horizontally attached two-strip cladding 3. After processing the clad strip into a pipe shape, it is formed into a pipe 5 by straight welding 4 or spiral welding, and the composite ring 6 is manufactured by cutting the pipe 5 to an appropriate size. The composite ring 6 has a magnetic hysteresis loss of 5000 erg cm ^-3 at 0°C.
It is characterized by having the above.

Also, in Figure 2, the magnetic hysteresis loss is
0° to 1 between two ferromagnetic metal alloy strips 1 and 1 with a Curie temperature of 10,000 erg cm ^-3 or higher and a Curie temperature of 400°C or higher.
A low Curie temperature material 2 having a Curie temperature of 150° C. is interposed and welded to form a horizontal three-strip cladding 3', the said crud strip is shaped into a pipe shape 5, and the horizontal three-striped cladding pipe 5 is made into appropriate dimensions. Magnetic history loss at 0℃ after cutting
Composite ring 6 with 5000 erg cm ^-3 or more was manufactured.

Furthermore, as a manufacturing method for the composite ring, the two ferromagnetic metal alloy strips 1 and 1 explained in FIG.
The composite ring 6 may be manufactured by punching out three horizontal clad strips 3', which are welded with the low Curie temperature material 2 interposed therebetween, as shown in FIG.

The composite ring according to the present invention has a circular cross-sectional shape, and the dimensions vary depending on the power transmission capacity of the electric wire, but the volume of the composite ring must be 3 cm ³ or more. Insertion thickness of low Curie temperature material in composite ring (W in Figure 5)
is preferably 0.2 to 10 mm, and when the low Curie temperature material is inserted in two places, the insertion thickness (W) should be 1/2 of the insertion thickness (W) when inserted in one place.

In the present invention, the reason why the Curie temperature of the low Curie temperature material to be inserted is limited to 0°C to 150°C is that if it is less than 0°C, it will not generate heat at the snow accretion start temperature of 3°C, so there will be no snow melting effect, and if it exceeds 150°C Even in the summer when there is no snow, it generates heat and causes power loss during transmission, which is undesirable.The desirable Curie temperature is 50℃~
It is 100℃. Also, the reason why the magnetic hysteresis loss at 0°C of the composite ring is set to 5000erg・cm ^-3 or more is as follows.
This is because there is almost no snow melting effect below 5000 erg·cm ^-3 , and the magnetic hysteresis loss at 0°C of a particularly effective composite ring is 20×10 ³ erg·cm ^-3 or more.

Magnetic hysteresis loss of ferromagnetic metal alloy strip is reduced to 10000erg・
The reason for limiting the temperature to cm ^-3 or higher is that below 10,000 erg cm ^-3 , a composite ring with a low Curie temperature material inserted would have a value of less than 5000 erg cm ^-3 , which would have almost no snow melting effect, so it is not particularly effective. is 50000erg・
cm ^-3 or higher.

The present invention will be explained below with reference to Examples.

Example 1 It has magnetic properties with a saturation magnetic flux density of 14100 gauss at 22°C, a coercive force of 4.1 Oe, and a magnetic hysteresis loss of 232 x 10 ³ erg cm ^-3 , width (115 mm-W) x thickness 6.5 mm.
× 200 mm long 0.2% C carbon steel strip and 30 mm width × 6.5 mm thickness × 200 mm length at Curie temperature 100 °C
%Ni-Fe alloy strip, or at a Curie temperature of 70℃,
31% Ni-8 with the same dimensions as the 30% Ni-Fe alloy strip above.
%Cr-Fe alloy strip was welded horizontally to form two clad strips as explained in Fig. 1, and the clad strips were made into outer diameter 43 mmφ x inner diameter 30 mmφ x length using the electric resistance welding method.
After producing a 200 mm pipe, the pipe was cut into a ring to produce a composite ring with an outer diameter of 43 mmφ, an inner diameter of 30 mm, and a height of 15 mm.

30% Ni-Fe alloy as a low Curie temperature material,
Figure 4 a, b, It is represented in c.

Figure 4a shows 30%Ni as a low Curie temperature material.
-Fe alloy is used, and each curve 1, 2, 3, 4, and 5 has a low Curie temperature material insertion thickness (W) of 0.
Represents mm, 0.5mm, 1.0mm, 2.0mm, 4.0mm.

Figure 4b shows 31% as a low Curie temperature material.
Using Ni-8%Cr-Fe alloy, 1, 2, 3, 4,
5 Each curve is the insertion thickness (W) of low Curie temperature material
represents the cases where are 0mm, 0.5mm, 1.0mm, 2.0mm, and 4.0mm, respectively.

The first curve in Figure 4c is for a low Curie temperature material.
For 30%Ni-Fe alloy, the two curves are 31%Ni-8%Cr-
The relationship between insertion thickness (W) and magnetic hysteresis loss ratio in the case of Fe alloy is shown.

Note that FIG. 5 shows the shape and dimensions of the ring used in the above test.

As is clear from FIGS. 4a, b, and c, the lower the Curie temperature of the low Curie temperature material and the thicker the insertion thickness (W), the lower the magnetic hysteresis loss at low temperatures, that is, the amount of heat generated. The magnetic hysteresis loss ratio of 0° C. to 30° C., that is, the ratio of the amount of heat generated at low temperature to that at high temperature is large.

Magnetic hysteresis loss at 0℃ is 26.5×10 ^-3 erg・
cm ^-3 and magnetic hysteresis loss ratio of 2.05 (low Curie temperature material, 31% Ni-8% Cr-Fe, Curie temperature 70℃, insertion thickness: 2 mm) of 120 mm ^2.
When attached to the ACSR and passed a current of 60Hz and 200A, when the atmosphere was -7℃, the wire temperature was 1℃, at which snow would accumulate, but the wire temperature was 10℃, at which snow would not accumulate on the composite ring.
The temperature rose to .

Furthermore, when the ambient temperature was 25°C, the wire temperature and composite ring temperature were both 46°C, and no heat generation was observed in the ring itself.

Example 2 Dimensions: Plate width (115 mm-W) 1/2 x plate thickness 6.5 mm x length 200 mm Example 1 as a low Curie temperature material between two 0.2% C carbon steel strips made of the same material as Example 1 A 31%Ni-8%Cr-Fe alloy strip with the same dimensions as in Example 1 was welded to form a horizontally attached 3-layer clad strip as shown in Figure 2, and the post-process was manufactured using the same method as in Example 1. When the ring was attached to the same wire as the ring, the same current was applied, and the ambient temperature was -7°C, the wire temperature was 1°C, at which snow would form, but the composite ring would not snow.10
℃, and when the ambient temperature was 23℃, the wire temperature and ring temperature were both the same temperature of 44℃, and no heat generation was observed in the composite ring itself, and the effect was the same as in Example 1.
It was the same as the composite ring manufactured at.

Example 3 The three horizontal cladding strips described in Example 2 were
As shown in the figure, a composite ring with an outer diameter of 43 mm x inner diameter of 30 mm x thickness of 6.5 mm was manufactured by punching into a ring shape while remaining flat, and two composite rings were laminated to form a composite ring in Examples 1 and 2. When attached to a wire similar to the above, the same current was applied, and the ambient temperature was -7°C, the wire temperature was 1°C, at which snow would form, but the composite ring temperature rose to 8°C, at which no snow would form, and the ambient temperature was -7°C. temperature 25
℃, both wire temperature and ring temperature are 46℃.
As with the composite rings manufactured in Examples 1 and 2, no heat generation was observed in the composite ring itself.

As described above, the present invention provides an effective composite ring that can be attached to electric wires at low cost and with good productivity in order to prevent wire breakage accidents and collapse of steel towers due to snow accumulation on electric wires.

[Brief explanation of drawings]

FIG. 1, FIG. 2, and FIG. 3 are explanatory diagrams showing embodiments of the present invention. Figures 4a, b, and c are charts showing the relationship between the material, insertion thickness, ambient temperature, and magnetic properties of the low Curie temperature material of the composite ring according to the present invention. FIG. 5 is a perspective view showing the shape and dimensions of the composite ring used in the characteristic test of the example. 1: Ferromagnetic metal alloy strip, 2: Low Curie temperature material, 3: 2-layer cladding with sideways, 3': 3-layered cladding with laterals, 4: welding, 5: pipe shape, 6: composite ring.

Claims (1)

[Claims] 1. Having a magnetic hysteresis loss of 10000erg cm ^-3 or more,
After welding a ferromagnetic metal alloy strip with a Curie temperature of 400°C or higher and a ferromagnetic metal alloy strip with a Curie temperature of 0°C to 150°C into a pipe shape, the pipe is cut into appropriate dimensions. After processing, the magnetic history loss at 0℃ is 5000erg・
A method for manufacturing a composite magnetic ring for snow melting, characterized by manufacturing a ring having a magnetic flux of cm ^-3 or more. 2 Has a magnetic hysteresis loss of 10000erg cm ^-3 or more,
A ferromagnetic metal alloy strip with a Curie temperature of 0℃ to 150℃ is interposed between two ferromagnetic metal alloy strips with a Curie temperature of 400℃ or higher, and the welded 3-layer clad strip is processed into a pipe shape. A method for manufacturing a composite magnetic ring for snow melting, comprising cutting the pipe into appropriate dimensions to manufacture a ring having a magnetic hysteresis loss of 5000 erg·cm ^-3 or more at 0°C. 3 Has a magnetic hysteresis loss of 10000erg cm ^-3 or more,
A ferromagnetic metal alloy strip with a Curie temperature of 0°C to 150°C is interposed between two ferromagnetic metal alloy strips with a Curie temperature of 400°C or higher, and a ring-shaped welded horizontally welded 3-layer clad strip is formed while remaining flat. The magnetic hysteresis loss at 0℃ is
A method for manufacturing a composite magnetic ring for snow melting, characterized by manufacturing a ring having a magnetic flux of 5000 erg cm ^-3 or more.