JPH03198312A - Iron core for swinging choke coil and its manufacture - Google Patents

Abstract

PURPOSE:To facilitate the control of inductance with small iron loss in high frequency area by combining a high permeability iron core made of amorphous alloy material with a low permeability iron core similarly made of amorphous alloy material. CONSTITUTION:A ring-shaped high permeability iron core is arranged inside, and a low permeability iron core 1b is arranged outside so as to constitute an iron core for a swinging choke coil. For the high permeability iron core 1a, any iron core material of the iron core material which is made of Co amorphous alloy, the iron core material which is made of Fe amorphous alloy and in which space is provided in one part of a magnetic field, and the iron core material where Fe amorphous alloy is oxidized and annealed for a certain time is used. Moreover, for the pow permeability iron core 1b, either iron core material of the iron core material which is made of Fe amorphous alloy material and in which space larger than the space of the iron core 1a is provided in one part of a magnetic path and the iron core material where Fe amorphous alloy is oxidized and annealed for a time longer than the oxidation and annealing time of the iron core 1a is used.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an iron core for a swinging choke coil using an amorphous alloy and a method for manufacturing the same.

(Prior art) When controlling a motor, a swinging choke coil is used in which the inductance is made as high as possible when the current value flowing through the coil is small, and when the current value becomes large, the inductance decreases and becomes approximately constant. When manufacturing, conventionally, for example, an air gap was provided in a part of the magnetic path of a toroidal core, and a high magnetic permeability material such as ferrite or permalloy was sandwiched there.

With this configuration, the area around the air gap has low magnetic permeability, while the material sandwiched in the air gap has high magnetic permeability. When the magnetic flux passes through the gap with high magnetic permeability and the inductance is kept high, and current begins to flow, the high permeability material in the gap becomes saturated, and then the magnetic flux flows through the low permeability area around the gap. This gave the so-called swinging characteristics of the coil.

(The invention is intended to solve! II! fi) However, according to such conventional means, there is a problem that there is a possibility that the cut surface may be short-circuited, which leads to an increase in iron loss.

Particularly in coils used in high frequency ranges, increased iron loss has been a fatal drawback.

This invention was made to solve the above problem, and its purpose is to provide an iron core for a swinging choke coil that has low iron loss, especially in the high frequency range, and can easily control inductance. The object of the present invention is to provide a manufacturing method thereof.

(Means for Solving the Problems) In order to achieve the above object, the present invention is characterized in that a high magnetic permeability iron core and a low magnetic permeability iron core made of an amorphous alloy are combined; An iron core material made of Co-based amorphous alloy, an iron core material made of Fe-based amorphous alloy with a gap in a part of the magnetic path, and Fe-based amorphous alloy material.
An iron core in which one of the iron core materials obtained by oxidizing and annealing a Fe-based amorphous alloy for a certain period of time is used as the high magnetic permeability iron core, and the iron core is made of an Fe-based amorphous alloy and has a gap larger than the above-mentioned gap in a part of the magnetic path. The high permeability iron core material and the low magnetic permeability iron core material are combined by using one of the iron core materials obtained by oxidizing and annealing an Fe-based amorphous alloy for a longer time than the above as the low magnetic permeability iron core. It is characterized by

(Function) With the above configuration, according to the present invention, when a very large current does not flow through the coil, magnetic flux passes through the high magnetic permeability iron core material to keep the inductance of the coil high, and when the current starts flowing, the high inductance increases. Since the magnetic permeability iron core material is saturated, the magnetic flux then passes through the low magnetic permeability iron core material, and the inductance of the coil decreases, and the inductance at this time remains approximately constant even if the current flowing through the coil increases. The so-called swing characteristics of the coil can be obtained.

The high magnetic permeability iron core may be made of a Co-based amorphous alloy, or may be made of an Fe-based amorphous alloy with a gap provided in a part of the magnetic path, or may be made of an F-based amorphous alloy.
It is obtained by oxidizing and annealing an e-based amorphous alloy.

In addition, a low magnetic permeability iron core can be obtained by using an Fe-based amorphous alloy as a material and providing a gap larger than the above-mentioned gap in a part of the magnetic path, or by oxidizing and annealing the Fe-based amorphous alloy for a longer time than the above. It will be done.

(Example) Hereinafter, preferred examples of the present invention will be described based on the drawings.

FIGS. 1(a), 1(c), and 1(c) show embodiments of a swinging choke coil core according to the present invention.

The present invention is characterized by a combination of a high magnetic permeability iron core and a low magnetic permeability iron core made of an amorphous alloy.

That is, in this embodiment, FIG. 1(a) shows an iron core for a swinging choke coil in which a ring-shaped high permeability iron core 1a is arranged on the inside and a low permeability iron core 1b is arranged on the outside. It is shown.

In addition, FIG. 1(b) shows an example in which, contrary to the above, a high magnetic permeability iron core 1a is placed on the outside and a low magnetic permeability iron core 1b is placed on the inside. C) shows an example in which a high magnetic permeability iron core 1a is arranged in the lower part and a low magnetic permeability iron core material 1b is arranged in the upper part.

Here, in order to obtain the high magnetic permeability iron core 1a, the following three methods can be considered, for example.

■ Uses an iron core material made of Co-based amorphous alloy.

■ Made of Fe-based amorphous alloy, a narrow gap is provided in a part of the magnetic path, and an iron core material is used with glass fiber-containing epoxy plates sandwiched between the gaps. ■Uses an iron core material made of Fe-based amorphous alloy that is oxidized and annealed in a short period of time.

Furthermore, in order to obtain the low magnetic permeability iron core ib, the following two methods can be considered, for example.

(2) Made of Fe-based amorphous alloy, a gap wider than (2) above is provided in a part of the magnetic path, and an iron core material with glass fiber-containing epoxy plates sandwiched therein is used.

(2) An iron core material is used in which an Fe-based amorphous alloy is oxidized and annealed for a longer time than in (1) above.

Therefore, the combinations of the high magnetic permeability iron core 1a and the low magnetic permeability iron core tb are as follows: ■ and ■, ■ and ■, ■ and ■, ■ and ■, ■ and ■
There are six ways, ■, and ■.

Next, the characteristics of a toroidal core formed by arranging a high magnetic permeability core and a low magnetic permeability core as shown in FIG. 1(a) will be described.

FIGS. 2(a) to 2(d) show hysteresis loops measured at a frequency of 4 Kl (z) for each core material before the two types of core materials are combined.

That is, Fig. 2(a) shows the hysteresis loop for the high magnetic permeability iron core 1a (the iron core material of ① above) made of Co-based amorphous alloy, and Fig. 2(b) shows the hysteresis loop for the high-permeability iron core 1a made of Co-based amorphous alloy. This is a hysteresis loop for the low magnetic permeability iron core 1b (the iron core material of (2) above) formed by oxidation annealing.

In addition, Fig. 2(C) shows the hysteresis loop for the high magnetic permeability iron core 1a (core material of ① above) obtained by oxidizing and annealing Fe-based amorphous alloy in a short time, and Fig. 2(d) shows the hysteresis loop of the F
This is a hysteresis loop for a low magnetic permeability iron core 1b (the iron core material of ①) obtained by oxidizing and annealing an e-based amorphous alloy for a long time.

As is clear from these characteristic diagrams, since the area surrounded by the hysteresis loop is small in all cases, it can be seen that these have characteristics of low hysteresis loss. In addition, although the iron cores shown in FIGS. 2(a) and (b) have high magnetic permeability,
Furthermore, although the cores shown in Figures 2(a) and (C) have low magnetic permeability, they are cores with constant magnetic permeability characteristics in which BIl/H11 is approximately constant compared to other core materials. Recognize.

FIG. 3 shows a hysteresis loop when a toroidal core for a swinging chiller coil is formed by combining the above core materials.

That is, Fig. 3(a) shows the hysteresis loop when the iron core materials of Fig. 2(a) and Fig. 2(b) are combined and measured, and Fig. 3(a) is the hysteresis loop of Fig. 2(C). This is the hysteresis loop when measured by combining the iron core material shown in FIG. 2(d).

According to the toroidal core formed in this way, in the initial state where very large current does not flow through the coil,
Magnetic flux passes through the high magnetic permeability iron core material 1a, keeping the inductance of the coil high, and when the current starts flowing, the high magnetic permeability iron core material 1a is saturated, so the next low i! A magnetic flux begins to pass through the i-magnetic iron core material 1b, and the inductance of the coil decreases, and the inductance at this time is maintained approximately constant even if the current flowing through the coil increases.

As is clear from FIGS. 3(a) and 3(b), the inclination angle of the loop changes as the magnetic field strength H- increases in positive and negative directions.

Figures 4(a) and (b) are shown in Figure 3 (
The relationship between the magnetomotive force measured for the toroidal core of a) and (b) and the AL value is shown.

As is clear from Figure 4(a), the magnetomotive force is 20 (A・T)
When the temperature is around 1.0 (μH/N2
), but when the magnetomotive force is 20 to 70 (A-T), the AL value suddenly decreases, and above this, the property remains almost flat even if the magnetomotive force changes (AL value is 0, lμH/ N
' degree).

This shows a similar tendency in FIG. 4(b), which has so-called swinging properties, and desired characteristics can be obtained by combining the iron cores.

As explained above, according to this embodiment, since an amorphous alloy is used as the material of the toroidal core, iron loss in the high frequency wt range is small, and a gap is provided in a part of the magnetic path. Compared to an iron core with high magnetic permeability material sandwiched between the
It has the advantages of no leakage magnetic flux and low iron loss. Furthermore, in the iron core of the type shown in FIGS. 1(a) and 1(c), leakage of magnetic flux can be prevented when the iron core material is oxidized and annealed on the outside.

In the present embodiment, the toroidal core of the type shown in FIG. 1(a) has been described as an example, but the characteristics are the same for the types of toroidal cores shown in FIG. 1 et al.) and FIG. 1(C).

(Effect of the invention) The present invention combines a high magnetic permeability iron core made of an amorphous alloy and a low magnetic permeability iron core, and also combines an iron core material made of a Co-based amorphous alloy and a Fe-based amorphous alloy as materials. The high magnetic permeability iron core is either an iron core material with a gap provided in a part of the magnetic path or an iron core material made of an Fe-based amorphous alloy that is oxidized and annealed for a certain period of time. By using either an iron core material in which a gap larger than the above-mentioned gap is provided in a part of the passage, or an iron core material in which an Fe-based amorphous alloy is oxidized and annealed for a longer time than the above as a low magnetic permeability iron core. Since an amorphous alloy is used as the material for the toroidal core, it has the effect of reducing iron loss in the high frequency range. In addition, the inductance can be easily controlled by appropriately selecting the magnetic permeability, volume, etc. of the iron core materials to be combined.

[Brief explanation of drawings]

Figures 1 (a), (b), and (c) are diagrams showing an example of an iron core for swinging coils, Figures 2 (a) and (c) are diagrams showing hysteresis loops for high permeability iron core materials, and Figure 2. 3) (d) is a diagram showing the hysteresis loop for a low magnetic permeability iron core material, and Figure 3 (a) and (b) are the hysteresis loops of a toroidal iron core made by combining a high magnetic permeability iron core material and a low magnetic permeability iron core material. FIG. 4(a) Φ) is a diagram showing the relationship between the magnetomotive force and the AL value in FIG. 3(a)(b). 1a...High permeability iron core lb...Low permeability iron core Fig. 1 Fig. 3 (0) (b) (C) Brn (KG+ Fig. 3 (b) 8m+G] NHA- T)

Claims (2)

[Claims] (1) An iron core for a swinging choke coil characterized by a combination of a high magnetic permeability iron core made of an amorphous alloy and a low magnetic permeability iron core also made of an amorphous alloy. (2) An iron core material made of a Co-based amorphous alloy,
The high magnetic permeability iron core is either an iron core material made of an Fe-based amorphous alloy with a gap provided in a part of the magnetic path, or an iron core material made of an Fe-based amorphous alloy oxidized and annealed for a certain period of time. An iron core material made of an amorphous alloy with a gap larger than the above gap in a part of the magnetic path, or an iron core material made of an Fe-based amorphous alloy that is oxidized and annealed for a longer time than the above. A method for manufacturing an iron core for a swinging choke coil, characterized in that it is manufactured as a magnetic iron core.