JPS60245205A - Amorphous core - Google Patents

Abstract

PURPOSE:To reduce iron loss and to improve magnetic characteristic by forming scratches with predetermined intervals in the longitudinal direction of wound amorphous magnetic thin belt. CONSTITUTION:A thin belt 1 of amorphous magnetic metal is wound and it is subjected to heat processing under the N2 gas ambient. Next, for example, the internal end of toroidal core is extracted and the scratches 2 are set at the inside of thin belt 1, namely toward the center of winding at a right angle to the ribbon width with intervals of 1mm.. The scratches 2 are formed at the inside in the shape of V at right angle to the longitudinal direction of thin belt 1 by drawing with a low pressure with a tungsten carbide needle. The winding is rewound to a toroidal core and is subjected to the casing. Such scratches 2 reduces a current loss and high frequency iron loss by segmentation of magnetic domain in the longitudinal direction. Simultaneously, pressure P is reduced in order to form the scratches 2 at a right angle to the longitudinal direction at the inside of winding surface of thin belt 1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an amorphous core used as a transformer core or the like in an electronic ballast for a discharge lamp.

[Background technology]

When an amorphous magnetic ribbon, especially an amorphous magnetic ribbon made of an iron alloy with large positive magnetostriction is wound to form a transformer core (toroidal core) as shown in Figures 3 and 4, its magnetic properties change. deteriorates. In particular, when used at high frequencies (10 KHz to several hundred KHz), the heat loss increases significantly and the core C generates heat, making it impossible to use it. The cause seems to be the pressure P generated inside each layer of the wound ribbon 1.

That is, when the amorphous magnetic ribbon 1 is toroidally wound as shown in the enlarged view of the core in FIG. 4, a tension P' is applied to the outside of each layer.
is applied, and a pressure P is applied to the inner side. Therefore, in the case of having positive magnetostriction, the magnetic properties deteriorate due to the influence of the pressure P.

Furthermore, since pressure is also applied to the core as a whole in the stacking direction, high frequency iron loss increases and magnetic permeability, coercive force, etc. decrease.

Amorphous magnetic metals do not have clear magnetic domains or crystal anisotropy, so even if the hysteresis loss is small, the eddy current product increases, and the latter (eddy current product) has a large negative effect, especially at high frequencies of about IKHz or higher. .

For example, the Institute of Electrical Engineers of Japan/Magnetics Research Group rMAG8
1-7. Mitsubishi Electric, large circle (January 24, 1981)
”, in order to investigate changes in magnetic properties due to bending, an inner diameter of φ20. φ40. φ60 [All units are amounts. DC magnetization characteristics, iron loss, excitation V with a toroidal core of
When A was measured, it was reported that the characteristics deteriorated significantly at φ20.

In addition, deterioration of characteristics due to stress may be caused by the core, that is, pressure is applied to the core C due to thermal expansion of the core during cooling after heat treatment, resulting in deterioration of the characteristics.

The following are typical examples with large positive magnetostriction. Chemical formulas are expressed in atomic percent.

Fe,. B.・・・・・・・・・・・・・・・・・・
... Magnetostriction λ, 31X10-6F e 116B7 C
7・・・・・・・・・・・・・・・Magnetostriction λ531
X10-6Fe 7BS I+. Bl□・・・・・・
・・・・・・Magnetostriction λ533X10-6Fe8□5ie
B+o ・・・・・・・・・Magnetostriction λ533X10
-6Fea+B+3s 14c2' +++++++Magnetostriction λ, 40X10-6F ea+B+3s ii, s C
z, s ”'Magnetostriction λ340X10-6 For example, Fe7q
METGLA which is an example of B+6s is (atomic %)
In the prototype example of S (trademark) 2605S-3, the high frequency iron loss of the toroidal core of 100 turns each for φ20 and φ40 is 950 mW/cc for the former and 600 mW/cc for the latter under the conditions of 50 Kl (z, 3 K Gauss). It was cc.

[Purpose of the invention]

An object of the present invention is to provide an amorphous core with low characteristics and particularly low iron loss.

[Disclosure of the invention]

The amorphous core of the first invention has scratches formed at predetermined intervals in the length direction of a wound amorphous magnetic ribbon.

Further, the amorphous core of the second invention is a wound amorphous magnetic ribbon in which thin crystallized portions are formed at predetermined intervals in the length direction. Since the thin crystallized parts are structurally brittle, they act similar to scratches.

That is, by forming a large number of scratches and thin crystallized portions as described above, the magnetic domain is subdivided in the longitudinal direction of the ribbon to form a large number of domain walls. by this,
This reduces the eddy current product and reduces high frequency iron loss.

Note that such processing increases hysteresis loss, so the iron loss of the commercial transformer actually increases. Therefore, the present invention is limited to use in the frequency range where the eddy current product accounts for most of the iron loss.

In addition to the above-mentioned amorphous alloys to which this invention is applied, Fe 46N is an iron-nisokel based alloy.
140P 14B6-"""λ, 7X10-'Fe 4
6N i 3@Mo a B +s--λ, 5X10
-6 can be given. However, compared to iron-based materials, it has less strain and is less effective against scratches and thin crystallized parts.

Example 1 (See Figure 1) METGLAS (Trademark>26053-3) (7) Width Low.

Thickness: 30 pm (D thin ribbon 1 was wound in a 2° tanner with an inner diameter of 30 ml, and heat-treated at 400° C. for 60 minutes in N2 gas.

Next, take it out from the terminal inside the toroidal core,
Scratches 2 as shown in the figure are made at right angles to the ribbon width at intervals of one fin, on the inside of the ribbon 1, that is, on the winding center side. The scratch 2 is formed by lightly scratching with a tungsten carbide needle, perpendicular to the length direction of the ribbon 1, and in a V-shape on the inside.

Then, they are sequentially re-wound onto a toroidal core with an inner diameter of 30 mm and made into a casing.

The high frequency iron loss of this core C is 590 mW/cc (5
0 KHz, 3 K Gauss), the iron loss could be reduced by about 15% compared to 700 m W /cc in the case of a similar core without scratches.

The scratches 2 reduce the eddy current product by subdividing the magnetic domains in the length direction, thereby reducing high-frequency iron loss.

In addition, since the scratches 2 (grooves) are formed inside the winding surface of the ribbon 1 at right angles to the length direction, the pressure P is reduced at the same time.

Example 2 (see Figure 2) METGLAS (trademark>26053-2) in Example 1
After heat treatment in the same manner as above, a red-hot tungsten wire was applied to the ribbon 1 at approximately right angles to the length direction at 31 intervals in the length direction to crystallize it in a linear shape. The effect of this thin crystallized portion 3 is 300 mW/cc (20K Hz, 3K
Gauss), the iron loss was reduced by about 10% compared to a similar sample without scratches and thin crystallized portions 3. Although the thin crystallized portions 3 are not scratches 2 (grooves) as in Example 1, they are knee-like in a m weave pattern, and the pressure can be reduced.

In addition, an embodiment of the present invention in which the scratches 2 and the thin crystallized portions 3 are formed in a direction oblique to the longitudinal direction of the ribbon 1 is also an embodiment of the present invention. Further, when the ribbon 1 has negative magnetostriction, a scratch 2 or a thin crystallized portion 3 is formed on the outer surface of the ribbon 1, which is also an embodiment of the present invention.

〔Effect of the invention〕

1st. In both of the second inventions, the scratches or thin crystallized portions subdivide the magnetic domain and reduce the eddy current product, so it is possible to reduce iron loss, and the pressure reduction also improves the magnetic properties. It has the effect of being able to

[Brief explanation of drawings]

FIG. 1 is an enlarged plan view of a portion of an embodiment of the first invention;
FIG. 2 is an enlarged plan view of a portion of an embodiment of the second invention;
FIG. 3 is a perspective view of the conventional example, and FIG. 4 is an enlarged plan view of a portion thereof. C...Core, 1...Amorphous magnetic ribbon, 2...Scratch, 3...Thin crystallized portion P2 Fig. 1 Fig. 3 Fig. 2 Fig. 4

Claims (1)

[Claims] (An amorphous core formed by forming scratches at predetermined intervals in the longitudinal direction of an amorphous magnetic ribbon wound around 11 times. (2) The scratches are formed by the length of the ribbon. The amorphous core according to claim 1, wherein the amorphous core is formed in a direction perpendicular to the direction and over the entire width. (3) The thin ribbon has positive magnetostriction, and the scratch The amorphous core according to claim (1), which is formed on the inner surface of the ribbon located on the winding center side. (4) The lengthwise direction of the wound amorphous magnetic ribbon. An amorphous core in which thin crystallized portions are formed at predetermined intervals.(5) The thin crystallized portions are formed in a direction perpendicular to the length direction of the ribbon and over the entire width. (6) The ribbon has positive magnetostriction, and the thin crystallized portion is on the inner surface of the ribbon located on the winding center side. An amorphous core according to claim (4) formed therein.