JPS60165705A - Wound magnetic core - Google Patents

Abstract

PURPOSE:To obtain wound iron core having excellent high frequency characteristic and showing less ageing effect by winding many sheets of amorphous ribbons through non-magnetic thin belt with the predetermined surface placed at the outside. CONSTITUTION:The five sheets or more amorphous ribbons A having the composition (Co1-x-yFexMny)100-a-b-cMaSibBc (0<=x<=0.1, 0<=y<=0.13, 0<=a<=6, 12<=b<= 18, 8<=c<=12) including one or two or morekinds of Cr, Mo, Nb, V, W, Ta, Tl, Zr, Hf, rare earth element are wound with the surface being in contact with the cooling roll at the time of manufacture placed outside. Thereby, a wound iron core which has improved pulse permeability mup, lowered the square ratio Br/Bm and has a low iron loss can be obtained. Moreover, when non-magnetic thin belt B is inserted between the ribbons A and a heat radiating effect is given to the non-magnetic thin belt, the aging effect of wound iron core can be lowered and can suitably be used for high frequency wherein temperature rise is large.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a wound magnetic core using an amorphous ribbon.

Conventionally, 50% Ni-F was used as a wound magnetic core used in high frequencies.
e-permalloy, 80% 11-"A par 71 coil-wound magnetic core using a thin plate such as e-permalloy was used.

Recently, power supplies used in electronic devices have become smaller.

With the increasing need for higher efficiency, switching power supplies are attracting attention.

In recent years, there has been a trend toward higher frequencies for switching power supplies in order to make them more compact. However, as the frequency becomes higher, heat generation due to iron loss in magnetic cores for lances, etc. used in switching power supplies increases. Currently, the main materials used for this purpose are Ferrai I magnetic cores and permalloy wound magnetic cores, but permalloy wound magnetic cores have a large iron loss at high frequencies, especially above 100kHz, which poses a practical problem. , because the Curie temperature is low and the saturation magnetic flux density is low) 8
There is a problem in that as the temperature increases, the magnetic flux density decreases.

In recent years, amorphous wound magnetic cores have attracted attention as an alternative to permalloy wound magnetic cores as they are suitable for high frequency applications.

However, since the residual magnetic flux density is low and a curved B-1-1 curve is suitable for a magnetic core for a transformer of a forward converter, an ordinary amorphous wound magnetic core is not very suitable. That is, there are methods such as heat treatment in a magnetic field to improve the B-H curve, but heat treatment in a magnetic field has very poor productivity. Furthermore, since it is used while being excited in the direction of the magnetic path, there is a problem that the square shape rises. Furthermore, although an amorphous wound magnetic core generates less heat than a permalloy wound magnetic core, it generates considerable heat at high frequencies due to the increase in eddy current.

Since amorphous metals are metastable substances, they change significantly over time when the temperature rises, and depending on the composition, problems may occur when actually used. Therefore, in conventional high-frequency wound cores using amorphous ribbons, special consideration is required to improve heat dissipation of the wound core as much as possible in order to reduce changes over time.

An object of the present invention is to improve the drawbacks of the above-mentioned prior art and provide a wound core with excellent high frequency characteristics.

In order to achieve the above object, the present invention is characterized in that a large number of amorphous ribbons produced by a liquid quenching method are stacked and wound with non-magnetic ribbons interposed as necessary to form a wound magnetic core. This has the advantage of lowering the residual magnetic flux density and realizing a wound core with excellent high-frequency characteristics, which is ideal for forward converter transformers and cutting high-frequency noise.

In the present invention, when a wound core is produced by stacking five or more amorphous ribbons, the pulse permeability is significantly improved, and it is suitable for forward converter lances and noise cutting applications. Better results can be obtained. In addition, if the amorphous ribbon is wound with the surface that has solidified in contact with the cooling roll on the outside, the iron loss at high frequencies is smaller than in the case where the surface that has solidified in contact with the cooling roll is wound on the inside, which is more preferable. You can get results.

This effect can also be obtained when some of the amorphous ribbons to be stacked are brought into contact with a cooling roll and the solidified surfaces are rolled outward.

In addition, in the present invention, winding one or many thin strips of non-magnetic metal or non-metal between the amorphous ribbons can improve heat dissipation from the wound core, so This has the effect of making it smaller. Of course, the ribbon used for this purpose may be a non-magnetic amorphous ribbon. In particular, if the non-magnetic thin ribbon is placed outside the wound core, heat dissipation will be further improved, and a wound core with even smaller changes over time can be realized.

In the present invention, the composition formula (C01-y, -y Fe
xMn/)jDO-a-b-(-M>S i bB
, [Here M is Or.

Mo, Nl), V, W, Ta, Ti, Zr, 1-1f.

one or more rare earth elements], 0≦×
≦0.1. O≦y≦0.13.0≦a≦6, 12≦b
When an amorphous alloy ribbon having the relationship of ≦18.8≦C≦12 is used, a particularly excellent wound core can be produced because iron loss is small and changes over time are small.

In the above composition, 0≦×≦0.1 is limited to ×
This is because when the magnetostriction exceeds 0.1, the magnetostriction becomes large and the high frequency characteristics deteriorate. Further, the reason for limiting 0≦y≦0.13 is that if y exceeds 0.13, the ribbon tends to become brittle and it becomes difficult to form a wound core. The reason why the value is limited to 0≦a≦6 is that if a exceeds 6, the saturation magnetic flux density becomes low and the Curie temperature decreases, making it unsuitable for practical use.

The reason why the range is limited to 12≦b≦18° and 8≦C≦12 is that within the above range, the ribbon is less likely to become brittle and has excellent high frequency properties.

The present invention will be explained below according to examples.

Example 1 FIG. 1 is a diagram showing an example of a schematic diagram of the structure of a wound magnetic core according to the present invention. (a) is amorphous ribbon A+
, A2, and A3 are wound on top of each other.

(1)) is a wound magnetic core composed of amorphous ribbons Aa, A5 and non-magnetic ribbon B1. (C) is an amorphous ribbon A6. This is a wound core made up of A7 and a non-magnetic ribbon B2 partially exposed outside the wound core.

Table 1 shows the wound core according to the present invention having the structure shown in FIG. This figure shows the results of actually measured comparisons of iron loss W% and squareness ratio Br/Baa in the case of a frequency of 20 kHz and a peak value of magnetic flux density of 2 KG in a wound magnetic core.

As is clear from Table 1, the core loss of the wound core according to the present invention is superior to that using a ferrite or permalloy core, is equal to or higher than that of the conventional amorphous wound core, and has the same squareness ratio. It uses materials with different compositions and is smaller than conventional amorphous wound cores.

7- Example 2 Figure 2 shows a COtloyF with the configuration shown in Figure 1(a).
130,3 M n5S '+5""l Frequency 100 in the wound core of the present invention using an amorphous ribbon
kl-lz, iron loss W% at peak value of magnetic flux density 2KG, pulse permeability μp when pulse width is 10μs, amplitude ΔB of magnetic flux density = 6KG, number of stacked amorphous ribbons for squareness ratio Br/Bee It is a diagram showing dependence.

Although iron loss does not depend much on the number of stacked amorphous ribbons, increasing the number of stacked amorphous ribbons lowers the squareness ratio and improves the pulse permeability μρ. It is clear that the effect is particularly remarkable when five or more amorphous ribbons are stacked.

Embodiment 3 FIG. 3 shows a wound magnetic core C9 of the present invention (FIG. 1 (C)) corresponding to FIG.
) and the conventional amorphous wound core E, respectively, the iron loss w at the frequency 100k)-12 and the peak value of the magnetic flux density 2KG.
FIG. 8 is a diagram showing the change in r/B In over time. The measurement was carried out at 100° C. while being excited in the direction of the magnetic path.

It can be seen that the wound magnetic cores C and D of the present invention, in which a non-magnetic thin ribbon is inserted between amorphous ribbons, have a small change over time and a small iron loss.

In particular, it is clear that the non-magnetic thin ribbon has a heat dissipating effect and the change in the winding core over time is small, making it more suitable for high frequency applications where the winding core has a large temperature and height.

As detailed below, the present invention reduces the amount of iron 10 in the wound magnetic core used at high frequencies, which has been a problem in the past, lowers the squareness ratio, increases the saturation magnetic field, and increases the pulse permeability. Therefore, it is possible to obtain a wound core suitable for high frequency lances, inductors, etc.

[Brief explanation of the drawing]

FIG. 1 shows an example of a schematic diagram of the structure of the wound core according to the present invention, and FIG. 2 shows the core loss W3// of the wound core according to the present invention.
, k , pulse permeability μp, and squareness ratio Br/B In are shown in dependence on the number of stacked amorphous ribbons. FIG. 3 is a diagram showing changes over time in the wound core according to the present invention and the conventional wound core. . △ , Δ , , A 3 , Aa, A 5 ,
As, A: Amorphous ribbon, B+,
B2: Non-magnetic ribbon, C, D: Wound magnetic core according to the present invention, "
: Conventional wound core. 11- Figure 3 Tuna M (Aour) 1982 Special W [Application No. 21444 Name of the invention Relationship to the case of person who corrects the winding magnetic core Patent applicant address 2-1-2 Maruuchi, Chiyoda-ku, Tokyo Name (5
08) Hitachi Metals Co., Ltd. Representative: Nori Kawano Address: 2-1-2 Marunouchi, Chiyoda-ku, Tokyo Hitachi Metals Co., Ltd. Phone: Tokyo 284-4642 (Representative) Name (5oo)
i) Patent Attorney Takaishi Tachibana Ma The "Detailed Description of the Invention" and "Brief Description of the Drawings" columns of the specification subject to the amendment. Contents of the amendment As shown in the attached sheet. ■The description in the "Detailed Description of the Invention" column is corrected as follows. Note 1, page 3, line 18, ``evil thing'' is corrected to ``bad''. 2. In line 19 of the same page, correct ``unilateral shape'' to ``square ratio.'' 3. On the same page, replace “increasing” with “increasing high.”
Correct. 4. Correct "square ratio" on page 7, line 19 to "square ratio." 5. Correct "unilateral ratio" in line 4 of page 8 to "square ratio". 6. Correct "unilateral ratio" to "square ratio" on page 9, line 7. 7. Correct "square ratio" in line 11 of the same page to "square ratio." 8. Correct "square ratio" on the last line of the same page to "square ratio." 9. Correct "square ratio" in line 12 of page 10 to "square ratio." ■The description in the "Brief explanation of drawings" column should be corrected as follows. 1. Correct "square ratio" in line 19 of page 10 to "unilateral ratio". that's all

Claims (1)

[Claims] 1. A wound magnetic core characterized in that a large number of amorphous ribbons produced by a liquid quenching method are layered and wound. 2. The wound magnetic core according to claim 1, wherein the number of ribbons is 5 or more. 3. The wound magnetic core according to claims 1 and 2, wherein the amorphous ribbon is wound with the surface solidified in contact with a cooling roll facing outward during manufacturing. 4. Place one non-magnetic ribbon between the amorphous ribbons.
The wound magnetic core according to claims 1, 2, and 3, characterized in that one or more pieces are inserted and wound. 5. The above amorphous ribbon has the composition formula (C01 leaf. Fe, Mn,), -, -, -6M, Si, B, [where M is Cr, Mo, Nb, V, W,
Ta, Ti, N'r. Claims 1, 2, and 3 are represented by one or more of 1-H, I earth elements-L] and have the following relationships: The wound magnetic core described in item 4. 0≦X≦0.1゜0≦y≦0.13. 0≦a≦6゜12≦b≦18゜8≦C≦12