JPS5934610A - Iron core - Google Patents

Abstract

PURPOSE:To prevent excessive characteristics as well as to contrive effective utilizatin of an iron core by a method wherein a gap material, consisting of ferrite stainless steel, is inserted in a part of core magnetic path. CONSTITUTION:A gap material 12 consisting of ferrite stainless steel is inserted in a part of the core magnetic path of a thin silicon steel core 11. When the above-mentioned gap material is composed of a non-magnetic gap material, the area of core cross section and the number of winding can be reduced and the cost of the titled core can also be cut down.

Description

[Detailed description of the invention] The present invention relates to an iron core used in a small reactor.

A small reactor is a device with an inductance wound around an iron core, and is used in switching power supplies, computer power supplies, etc. This small reactor includes a choke coil,
This includes what is called an inductor.

Conventionally, in this type of core, a non-magnetic gap material 2 is sunk into a part of a thin silicon steel core 1, as shown in FIG. This iron core has current-inductance characteristics as shown in FIG. 2 when it is wound to form a small reactor. In this case, it is sufficient that the inductance value for the current is constant up to the rated current (for example, 5A), but in the case of a conventional small reactor, the inductance value is about twice the rated current as shown in Figure 1; The current is about twice that of the current, resulting in excessive characteristics, and the number of turns is large, causing the problem that the iron core is not fully utilized.

In order to eliminate excessive characteristics in the conventional structure, it is sufficient to reduce the gap length of the one-dimensional gap material 2, but gears! The thickness of the cutting whetstone for forming is 0.3 mm.
Because of the above, there is a limit to the gap length. In addition, conventional gap materials such as Solespode and force laminated plates have large thickness tolerances and a narrow range of selection.

The present invention has been made in view of the above circumstances, and its purpose is to prevent excessive characteristic vibration and to effectively utilize the iron core by using ferritic stainless steel instead of non-magnetic Gyazzo material. An iron core for a small reactor that can be used is highly desirable.

The present invention will be explained below with reference to the drawings.

FIG. 3 shows an iron core t' according to the present invention, in which a gap material 12 made of ferritic stainless steel is embedded in a part of the core magnetic path of a thin silicon steel core 1.

This iron core has the following characteristics.

The codes are according to Table 1.

Table 1 First, in the case of a conventional non-maternal gap, if the number of turns of the winding on the iron core is 4n, then the inductance is -n! L = - 1 (A.

Next, in the case of the Latin 1 nos gap according to the present invention, it becomes as follows.

In order to make the inductance the same as when using a non-magnetic gap, from the above formula, l! Day /! It may be set to 0 μ8 μ0.

In other words, in order to obtain the same inductance, in the case of a stainless steel gap, compared to a non-magnetic gap, μ8/μ0
All double length ones can be used. If the gap length is the same as the non-magnetic gap, using a stainless steel gap is equivalent to inserting a non-magnetic gap that is .mu.0/.mu.a times thinner.Next, specific embodiments of the present invention will be described.

A thin silicon steel having a thickness of 0.05 mm was used as the iron core, and the dimensions were 10 mm in width, 25 mm in inner diameter, 35 mm in outer diameter, and 1 mm in gap length 'a'. Also, S as a gap material.
tJ S 4.3 Q 13 A finishing phase (ferritic stainless steel) was used. A small reactor was fabricated by winding this iron core, and its current-inductance characteristics were investigated. The results are shown in FIG. 4 by curve A'f.

For comparison, a small reactor of the same dimensions was fabricated using a non-magnetic gap material, and its current-inductance characteristics were investigated.

The results are shown by curve B in FIG.

A conventional small reactor for comparison has a rating of 5A and 100μ.
10 to 12A as shown in curve B.
It maintains 0 μI"'11, which is excessive quality.

On the other hand, the small reactor according to the present invention has a current of 1-5
At A, the inductance L is 400 μII. Here, μ2 magnetic permeability (I4/m) S: Core cross-sectional area (Jr?) 1 m; Iron core m path length (m) N: Number of turns. Therefore, according to the present invention, the rating is 5 A, 100μ
In order to obtain a small reactor of H, the iron core breakage rate or the number of windings can be reduced to H, and the cost can be reduced.

As a reference example, the characteristics of a small reactor consisting of an iron core using a powdered iron core in the gear rough month are shown. This iron core is 0
．． Using thin silicon steel with a thickness of 0.05 mm, the height is 10 mm,
It has an outer diameter of 35+nm, a gap length of 4 mm, and a dust core is inserted therein. The current-inductance characteristic of a small reactor in which all wires are wound around this iron core is shown by curve C in FIG. In addition, curve B is obtained by inserting a non-magnetic gear tooth material of the same length instead of a dust core.

This small reactor has a large inductance 2 when the current is small and a small inductance 2 when the current is large, so it is suitable for an anode, a reactor, a supersaturated reactor, etc.

As described above, according to the present invention, the same effect as using a thin non-magnetic gap material can be obtained without reducing the gap length. Therefore, when this iron core Z small fr9 axle is used, it is possible to reduce the iron core material cost or side line man-hours. In addition, since ferrite stainless steel is used, there is a wide range of selection and small tolerances in thickness, so
There are significant effects such as the ability to stabilize the quality of small reactors.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a conventional iron core for a small reactor, Fig. 2 is a diagram showing the current-inductance characteristics of a small reactor using the same iron core, and Fig. 3 is a perspective view of a conventional iron core for a small reactor. Figure 4 is a diagram showing the current-inductance characteristics of a small reactor using the same iron core in comparison with a conventional one, and Figure 5 is a diagram showing the current-inductance characteristics of a small reactor for reference. , 11...Gap material made of thin silicon steel core, 12...Gap material made of ferritic stainless steel Applicant's representative Patent attorney Narihiko Suzuki Star map of spear 2 Illustration guide (A) Illustration of spear 3 Illustration of spear 4 q Worn 1(A) 3IP5 diagram

Claims (1)

[Claims] An iron core made by sandwiching a gap material made of ferritic stainless steel into a part of the iron core magnetic path.