JPS62124252A - 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. CONSTITUTION:The following amorphous alloy is applied to a magnetic core 1 mentioned below of the above device detecting the electric current I flowing through a conductor 2 passing through the hole of an annular magnetic core 1: an alloy having a composition represented by (Co1-a-bFeaMb)100-x-ySixBy, where M is one or more kinds selected from Ti, Cr, Ni, Cu, Zr, Nb, Mn, V, Mo, Hf, Ta, W, and elements of platinum group, 0<=a<0.12, 0<=b<0.25, 0<=x<=25, 5<=y<=30, and 20<=x+y<=33.

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 Topics] Conventional current detection devices using magnetic materials include current detection devices that detect current in a non-contact state using an annular magnetic core. It is disclosed in No. 60-173475, Japanese Patent Application Laid-open No. 80-173478, 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 conductor (2) through which a non-measured current is conducted is inserted into the hole of a wound or laminated single-hole annular magnetic core (1).
), 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, it was found that a Co-based amorphous alloy having the following composition was superior. That is, the present invention is used for an annular magnetic core of a current detection device that detects a current flowing through a conductor with an annular magnetic core arranged such that a conductor through which a current to be measured passes through a hole in the magnetic core (Co FeM) 5iB1-a. -b
a bx 100-x-y x yM;
Ti, Cr, Ni, Cu, Zr, Nb.

At least one selected from Mn, V, Mo, Hf, Ta, W and platinum group elements 0≦a≦0.12 0≦b≦0.25 0≦b≦0.25 5≦y≦30 20≦x+y The present invention is an amorphous alloy for a current detection device, characterized by having a composition of ≦33. 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.

B is essential when producing an amorphous alloy, and requires a minimum content of 5 atomic %, preferably 10 atomic % or more. . 30
If it exceeds atomic percent, the magnetic properties of the amorphous alloy will deteriorate. Si facilitates the formation of amorphous alloys, and
It increases the crystallization temperature by 2' and improves the thermal stability of amorphous alloys. This effect is exhibited at 25 atomic % or less. Furthermore, if the total amount of Si and B exceeds 33 atom%, the Curie temperature will become low and it will not be practical.
If it is less than this, the thermal stability of the amorphous alloy will decrease, as well as current detection sensitivity and output thermal stability. Especially Si
And the total amount of B is 25 to 29 atoms? 6 is the best. Furthermore, the detection sensitivity is higher when Si and El are more than Bit.

Although Fe is not an essential component, by including a small amount of Fe, current detection sensitivity and output can be significantly increased. Adding too much will actually cause a decrease in current detection sensitivity and output, so a≦0.12 is set. Preferably, 0.03≦a≦0.08.

The M component is a component that improves the thermal stability of the amorphous alloy,
It also improves current detection sensitivity and output thermal stability. Especially Zr, Nb, Mo, Hf, Ta.

W is effective in increasing the crystallization temperature of amorphous alloys. Cr, Cu, and platinum group elements also improve the corrosion resistance of amorphous alloys. Furthermore, Ni and Mn are effective in cases where a high saturation magnetic flux density is required because the saturation magnetic flux density decreases less than other elements.

Addition of the M component exhibits its effect in a small amount, but when b>0.
Addition of 25 lowers the Curie temperature and impairs practicality. Preferably, 0.01≦b≦0.15.

The Curie temperature (Tc) of the amorphous alloy of the present invention varies depending on its composition, manufacturing conditions, etc., but is 160≦Tc≦350°C.
, and more preferably 180≦Tc≦320°C. If the Curie temperature is too high, the aging characteristics of the output will deteriorate,
Furthermore, if the Curie temperature is low, the temperature characteristics of the output will deteriorate.

In addition, the amorphous alloy of the present invention is heat-treated at a temperature below the crystallization temperature and above the Curie temperature, if necessary. In particular, 1 to 50 deg/w
In is preferred. Further, the heat treatment is not limited to one time, but may be performed in multiple stages.

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 more,
It is preferable to use a plate thickness of ~25 μm and a diameter of 30 to 100 μm. 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-a range 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 requires fewer detection windings in order to obtain sensitivity comparable to conventional techniques.

In addition, it has excellent thermal stability of output and sensitivity as well as the thermal stability of amorphous alloys, so it is very effective in practice.

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

(Example 1) (CoFeNi)SiB0.92
An amorphous alloy ribbon (width 10 mm, plate thickness 20 μm) having a composition of 0.08 0.02 71 17 12 was produced by a single roll method. This amorphous alloy ribbon has an outer diameter of 1
Wound to form a single-hole magnetic core with a diameter of 8 mm and an inner diameter of 12 mm.
After heat treatment at 440° C. and cooling at a rate of 5 deg/1 nln, a current detection device as shown in FIG. 1 was constructed. The Curie temperature of the amorphous alloy was 220°C.

Next is the conductor (2)! , : The peak value of the pulse voltage generated between the detection windings (3) when an alternating current IA of 50 Hz was applied was measured. Unit cross section of pulse voltage.

The value (V) per turn of the detection winding is 720 (mv/
c[ll-A-T). For comparison, a similar experiment was conducted on a conventionally used ferrite core, but the value was V-3.24, which was extremely small. In order to obtain a practical level output with a ferrite core, a very thick detection winding of about 3,000 turns is required, but by using the amorphous alloy of the present invention, the detection winding can be significantly reduced. Ru.

(Example 2) Co-based amorphous alloys shown in Table 1 were produced in the same manner as in Example 1, and after core production, optimal heat treatment was performed to construct a current sensor. Table 1 shows the same V values as in Example 1, as well as V at room temperature. Variation ΔV of V at 100°C for the value of
(-Vo-V') is shown as a relative value.

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

Table 1 (1) Table 1 (2) Figure 3 shows the aging characteristics of the output. For comparison with the amorphous alloy of Example 1, the properties of Sample 16 in Table 1 are also shown. As is clear from FIG. 3, it can be seen that the present invention has better aging characteristics.

[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 diagram of aging characteristics of the output. 1... Annular magnetic core 2... Conductor 3... Detection winding Representative patent attorney Noriyuki Noriyuki Yudo Takehana Kikuo Figure 1 Figure 2

Claims (1)

[Claims] (1) Used in the annular magnetic core of a current detection device that detects the current flowing through the conductor with an annular magnetic core arranged so that the conductor through which the current to be measured passes through the hole in the magnetic core (Co_1_-_a_-_bFe_aM_b)_1_0
_0_-_x_-_ySi_xB_yM; Ti, Cr,
Ni, Cu, Zr, Nb, Mn, V, Mo, Hf, Ta
, W, and at least one element selected from platinum group elements, having a composition of 0≦a≦0.12 0≦b≦0.25 0≦x≦25 5≦y≦30 20≦x+y≦33 Amorphous alloy for current detection devices.