JPS62124250A - Amorphous alloy for electric current-detecting device - Google Patents

Abstract

PURPOSE:To improve thermal stability of output and sensitivity as well as thermal stability of the titled alloy to be obtained and to obtain an electric current-detecting device having high sensitivity and high output by specifying a composition and by carrying out heat treatment in the magnetic field. CONSTITUTION:The following amorphous alloy is applied to a magnetic core 1 of above-mentioned device which detects the electric current I flowing through a conductor 2 passing through the hole of an annular magnetic core 1: an alloy which has a composition represented by (t1-aMa)100-xXx and is heat-treated in the magnetic field; where T is Fe and/or C o (which may be replaced by Ni by up to 60atomic%); M is one or more kinds selected from Ti, Cr, Cu, Zr, Nb, Mn, V, Mo, Hf, Ta, W, and elements of platinum proup; X is one or more elements among Si, B, P, and C; 0<=a<=0.25; and 15<=x<=30.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a current detection device, and particularly to an amorphous alloy suitable for a device capable of detecting current in a non-contact state using an annular magnetic core.

[Technical background of the invention and its problems] Conventionally, as a current detection device using a magnetic material, there is a current detection device that detects current in a non-contact state using an annular magnetic core. It is disclosed in No. 60-173475, Japanese Patent Application Laid-Open No. 60-173476, etc.
For alternating current, zero-phase current transformers are widely used as earth leakage circuit breakers. The basic configuration of these current detection devices is shown in FIG. In other words, a non-M1 constant current conductor (
2), and the current flowing through the conductor is detected by the voltage induced in the detection winding (3) applied to the annular magnetic core. For example, when a sinusoidal current is passed through the conductor (2), a pulse voltage as shown in FIG. 2 is generated. This pulse voltage is generated by a sudden change in magnetic flux near the coercive force of the annular magnetic core (1), and changes depending on the current flowing through the conductor (2). The obtained pulses are processed by an appropriate processing circuit in the subsequent stage, and the current flowing through the conductor (2) is detected.

Such current detection devices have not yet achieved sufficient detection sensitivity, and it is desired to develop a device that improves this point.

[Object of the invention] The present invention has been made in consideration of the above points, and has high sensitivity,
The purpose of the present invention is to provide a high-output current detection device.

[Summary of the Invention] For the above purpose, the present invention has advanced research on magnetic materials used in annular magnetic cores. As a result, we found that an amorphous alloy heat-treated in a magnetic field is superior as described below. That is, the present invention provides an annular magnetic core for use in a current detection device that detects a current flowing through a conductor that is arranged such that the conductor through which the current to be measured passes through a hole in the magnetic core.
-a a 1.00-X XX (TM) T; At least one of Fe and Co (up to 60 atomic% Ni
) M; Ti, Cr, Cu, Zr, Nb, Mn.

At least one type X selected from V, Mo, Hf, Ta, W, and platinum group elements; At least one type selected from Si, B, P, and C 0≦a≦0. This is an amorphous alloy for a current detection device, which has a composition of 2 15≦x≦30 and has been subjected to heat treatment in a magnetic field. When such an amorphous alloy is used as the annular magnetic core of a current detection device, high sensitivity and high output can be obtained.

First, the composition of the alloy of the present invention will be explained.

X is essential for the production of amorphous alloys. If it exceeds 30 atomic %, the magnetic properties of the amorphous alloy will deteriorate. S
The combination of i and B is most preferred because it facilitates the formation of an amorphous alloy, increases the crystallization temperature, and improves the thermal stability of the amorphous alloy.

The T component is an essential element to obtain high squareness, and Co
and at least one of Fe. If necessary, Ni may be substituted, but since a large amount of substitution deteriorates the magnetic properties, the amount is limited to 60 at % or less.

Particularly preferred is a combination of Fe, Ni, Co, and Fe. For example, in the case of Fe and Ni, 1-b-c b e 1oo-x XX (Fe
NiM) M; Ti, Cr, Cu, Z+t, Nb, Mn.

At least one member selected from V, Mo, If, Ta, W, and platinum group elements preferably has a composition of 0.1≦b≦0.6, 0≦c≦0.25, 15≦x≦30. High sensitivity and high output can be obtained within this range. The M component is a component that improves the thermal stability of the amorphous alloy, and also improves current detection sensitivity and output thermal stability. Especially Zr and Nb.

Mo, Hf, Ta, and W have a q effect in increasing the crystallization temperature of an amorphous alloy. Also Cr, Cu.

Platinum group elements are effective in improving the corrosion resistance of amorphous alloys. Although the addition of M component exhibits its effect in small amounts, c>
Addition of Q,25 causes a decrease in the Curie temperature, impairing practicality. Preferably 0.01≦c≦0.15
It is.

In addition, in the case of Co and Fe, (C01-de de 100-x XX
FeM) M; Ti, Cr, Cu, Zr, Nb, Mn.

The composition preferably includes at least one selected from Ni, V, Mo, Hf, Ta, W, and platinum group elements O≦d≦0.12 0≦e≦0.25 15≦x≦30. By containing a small amount of Fe,
Current detection sensitivity and output can be significantly increased.

Adding too much will actually lead to a decline in properties, so
d≦0.12. Preferably, 0.03≦d≦0.
It is 08.

The M component is the same as in the above case, and Ni and Mn are effective when a high saturation magnetic flux density is required because the saturation magnetic flux density decreases less than other elements.

Further, it is particularly excellent when Si or B is selected as the X component, and is expressed as shown below.

(Fe NiM) 5iB1-b-c
b c 100-y-z y z(C
o FeM) 5iB1-de
d c 100-y-z y zO≦y≦
25 7≦z<30 20≦y+z≦30 In this range, both current detection sensitivity and output are good.

In the present invention, heat treatment in a magnetic field is performed. This heat treatment in a magnetic field is effective at temperatures below the Curie temperature (Tc). Further, it is preferable to perform this heat treatment in a magnetic field after performing a heat treatment for removing strain at a temperature below the crystallization temperature (Tx). Therefore, a magnetic field may be applied during cooling after the strain relief heat treatment, or the strain relief heat treatment may be performed with the magnetic field applied and then cooled, or it may be a completely independent process. Further, the direction in which the magnetic field is applied may be either the width direction or the longitudinal direction of the amorphous alloy ribbon. The applied magnetic field is about 0.50e to 2kOe, and the conditions can be set as appropriate. Although the Curie temperature (Tc) of the amorphous alloy of the present invention varies depending on its composition, manufacturing conditions, etc., heat treatment in a magnetic field is particularly effective when the temperature is 200° C. or higher, particularly 230° C. or higher.

The amorphous alloy of the present invention can be obtained by a commonly used liquid quenching method in which a molten alloy is quenched at a cooling rate of about 105° C./second or higher, such as a single roll method.

A current detection device can be used for a current detection device by winding a thin strip of the amorphous alloy of the present invention, stacking ring-shaped samples made by etching or punching the thin strip with a mold, or winding a thin amorphous alloy wire. Used as an annular magnetic core. The thickness of the amorphous alloy ribbon and the diameter of the thin wire are determined depending on the frequency of the current to be measured. Usually, a plate with a thickness of 10 to 50 μm and a diameter of 30 to 150 μm is used, and in the high frequency range of 1 kHz or higher,
It is preferable to use a plate thickness of 5 μm and a diameter of 30 to 100 μm. Note that the detection frequency range of the current detection device according to the present invention is from about 10 Hz to about MHz.

Further, the annular magnetic core is not limited to one, but may be used in combination. In this case, by combining magnetic cores with different characteristics, effects such as expansion of the measurement current range and output temperature compensation can be obtained, for example.

The amorphous alloy of the present invention can be used, for example, in devices that utilize pulsed voltage generated by current, such as current control in inverter circuits, zero-phase current transformers, and zero-crossing detectors that utilize pulse generation.

[Effects of the Invention] As explained above, according to the present invention, a current detection device with high sensitivity and high output can be obtained. Therefore, it is effective in detecting minute currents and minute changes in current, and the number of detection windings can be reduced to obtain the same level of sensitivity as the conventional method. 7 In addition to the thermal stability of amorphous alloys, it also has excellent thermal stability of output and sensitivity, and also has good linearity of detection output, so it has excellent detection accuracy over a wide current range and is very effective in practice. .

[Embodiments of the invention] The present invention will be explained in detail below.

(Example 1) 0.5 0.5 )7BSi8 B14" Composition 0) I
F: (F e Ni quality alloy ribbon (width IQ mm, plate thickness 20 μm) was produced by a single roll method (Tc - 350°C). This amorphous alloy ribbon was rolled into a single roll with an outer diameter of 18 mm and an inner diameter of 12 mm. It was wound to form a hole magnetic core at 400°C.

After strain relief heat treatment of 20m1n, lh, 200e.

After heat treatment in a magnetic field at 320° C., the mixture was slowly cooled, and a current detection device as shown in FIG. 1 was constructed.

Next, when a 50 Hz alternating current is passed through the conductor (2), the peak value of the pulse voltage generated between the detection windings (3) is measured, and the unit cross-sectional area of the pulse voltage and the value per turn of the detection winding ( ffl■/C112·T) is shown in FIG. For comparison, a similar experiment was conducted using a conventionally used ferrite core.

As is clear from FIG. 3, the present invention has higher sensitivity and higher output, and is also superior in output linearity.

In order to obtain a practical level output with a ferrite core, 3
A very large sensing winding, on the order of 0.000 tan, is required, but by using the amorphous alloy of the present invention, the sensing winding is significantly reduced.

(Example 2) 0.92 0.05 0.03) 75Si12B
An amorphous alloy ribbon (width 10 mm, plate thickness 20 μm) having a composition of 13” (CoFeNb) was produced by a single roll method (Tc-290°C), and an amorphous alloy ribbon with an outer diameter of 18 mm and an inner diameter of It was wound to form a 12 mm single-hole magnetic core at 460°C.

After strain relief heat treatment of 30m1n, lh, 50e.

After heat treatment in a magnetic field at 250° C., the mixture was slowly cooled, and a current detection device as shown in FIG. 1 was constructed.

Next, when a 50 Hz alternating current is passed through the conductor (2), the peak value of the pulse voltage generated between the detection windings (3) is measured, and the unit cross-sectional area of the pulse voltage and the value per turn of the detection winding ( a+V/am2 ・T) is shown in FIG.

As is clear from FIG. 3, the present invention has high sensitivity and high output, and also has excellent output linearity.

(Example 3) The amorphous alloy shown in Table 1 was produced in the same manner as in Example 1, and a current sensor was constructed. Table 1 shows the same V values (per IA) as in Example 1.

As is clear from Table 1, according to the present invention, a current detection device with high sensitivity and high output can be obtained.

Margin below Table 1 (1) Table 1 (2)

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the current detection device, FIG. 2 is a diagram showing the relationship between the current to be measured and pulse voltage, and FIG. 3 is a current-output characteristic curve diagram. 1... Annular magnetic core 2... Conductor 3... Detection winding Agent Patent attorney Nori Chika Ken Yudo Kikuo Takehana Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] (1) Used in the annular magnetic core of a current detection device that detects the current flowing in the conductor by the annular magnetic core arranged so that the conductor through which the current to be measured passes through the hole in the magnetic core (T_1_- _aM_a)_1_0_0_-_xX_x
T; at least one of Fe, Co (up to 60 atomic% Ni
) M; Ti, Cr, Cu, Zr, Nb, Mn, V, Mo,
At least one selected from Hf, Ta, W, and platinum group elements An amorphous alloy for current detection devices characterized by being subjected to heat treatment. (2) In claim 1, (Fe_1_-_b_-_cNi_bM_c)_1_0
_0_-_xX_xM; Ti, Cr, Cu, Zr, Nb
, Mn, V, Mo, Hf, Ta, W, and at least one platinum group element having a composition of 0.1≦b≦0.6 0≦c≦0.25 15≦x≦30 Amorphous alloy for current detection device. (3) In claim 1, (Co_1_-_d_-_eFe_dM_e)_1_0
_0_-_xX_xM; Ti, Cr, Cu, Zr, Nb
, Mn, Ni, V, Mo, Hf, Ta, W, and at least one platinum group element having a composition of 0≦d≦0.12 0≦e≦0.25 15≦x≦30 Amorphous alloy for current detection device.