JPS61181114A - Manufacture of rolled iron core - Google Patents

Abstract

PURPOSE:To improve rectangularity using magnetic elastic effect by adding a bending stress to an amorphous magnetic alloy thin belt. CONSTITUTION:A rolled iron core 2 is formed by winding amorphous magnetic alloy thin belt 1 having positive or negative magnetic stress except for zero to a bobbin 3a having a larger diameter. Namely, a rolled iron core 2 is formed by adding a bending stress corresponding to a larger bending diameter and an internal stress is eliminated by executing annealing to such rolled iron core 2. Thereafter, an amorphous magnetic alloy thin belt 1 is wound again to a bobbin 3b having smaller diameter. Namely, a stress as large as the difference can be given to the rolled iron core 2 by giving a bending stress corresponding to such small diameter. In this case, it is assumed that stresses having directivity are applied to each part of amorphous magnetic alloy thin belt 1 in place of a plurality of random stresses before the annealing for eliminating stress, namely a large tension is applied to the external size while a large compress force is applied to the internal side. Thereby, high rectangularity can be achieved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a wound core made of an amorphous magnetic alloy ribbon, which is used in electromagnetic induction equipment such as a transformer and a reactor μ.

[Technical background of the invention and its problems]

In recent years, there has been a tendency for amorphous magnetic alloys to be used as iron core materials for electromagnetic induction devices in place of conventional magnetic materials such as silicon steel and Fe--Ni alloys. The reason why this material is attracting attention is that it has a specific resistance of approximately 120 to 150 μΩ/cIII.
- (Amorphous magnetic material product name 2605 manufactured by Aphid Co., Ltd.
In the case of S2), it is a low material, for example, has a value about three times that of a silicon steel plate, so it can reduce current loss, which is not the main factor of iron loss, and has low iron inertia even in the high frequency range. Two points can be cited: the ability to exhibit high performance, and the ability to reduce hysteresis loss, which is also the main cause of iron loss, by performing annealing (heat treatment) in a magnetic field.

The purpose of annealing in a magnetic field is to remove the complex distortions introduced into the ribbon when the amorphous magnetic alloy ribbon is rapidly cooled. The magnetic rod properties, which have deteriorated in response to strain introduced in a complicated manner due to the high stress sensitivity inherent in the material, are greatly improved by the annealing, resulting in effects such as a reduction in stealth loss coercive force. When an iron core made of such an amorphous magnetic alloy ribbon is subjected to complex strain again during processing and forming after annealing, the magnetic properties will deteriorate again due to its high stress sensitivity. As a countermeasure to this problem, JP-A-59-410
Publication No. 9 discloses the use of a mode μ mode resin that does not cause mild distortion during curing, and cites silicone resin as a good resin.

Conversely, it is also being considered to actively utilize the high stress sensitivity of amorphous magnetic alloy ribbons. Utilizing the fact that applying tension in the magnetization direction of a material exhibiting positive magnetostriction improves the magnetic properties, Japanese Patent Application Laid-Open No. 58-52812 discloses a method for winding an amorphous magnetic alloy ribbon around an iron core. A method has been proposed in which a tension of 8/- is applied in the winding direction to reduce iron loss.

Amorphous magnetic alloy ribbons are characterized by low core loss characteristics, and the above two proposals are also examples of methods for exhibiting low core loss characteristics. However, there is also a method of using it as an iron core that concerns the squareness of its magnetization curve. For example, it is a pulse transformer or a saturable reactor. For saturable reactor p,
It is used for magnetic amplifiers and self-excited oscillation in switching regulators, but high saturation magnetization, large squareness ratio, and small coercive force are required to achieve miniaturization and high efficiency, which are the technical challenges of switching regulators. . Conventionally,
Supermalloy, ferrite, and the like have been used, but problems such as squareness ratio or saturation magnetization have caused problems, and therefore Co-based amorphous magnetic alloy ribbons having zero magnetostriction are currently being used. However, this material also has a saturation magnetization of 0.72T.
(Tesler) Well, it cannot be said that the saturation magnetization is still sufficient.

For the above reasons, it is possible to apply iron-based amorphous magnetic alloy ribbons, which have large saturation magnetization and exhibit good magnetic properties even in the high frequency range, to pulse transformers and saturable reactor μ cores. Although desired, the iron-based amorphous alloy ribbon is currently 8
There was a problem that only a squareness ratio of about 0.096 could be achieved.

[Purpose of the invention]

The present invention has been made based on the above circumstances, and an object of the present invention is to provide a method for manufacturing a wound core made of an amorphous magnetic alloy ribbon that can improve the squareness of the magnetization curve.

[Summary of the invention]

The method for manufacturing a wound core of the present invention includes annealing an amorphous magnetic alloy ribbon having non-zero magnetostriction to a zero or arbitrary bending diameter, and then rewinding the ribbon to a different desired bending diameter. It is characterized by this. That is, by applying bending stress to the amorphous magnetic alloy ribbon, the squareness is improved by utilizing the magnetoelastic effect.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a wound core 2 is formed by winding an amorphous magnetic alloy ribbon 1 having non-zero positive or negative magnetostriction around a winding frame 3a having a large diameter. That is, the wound core 2 is formed by applying bending stress corresponding to a large bending diameter, and this wound core 2 is
The amorphous magnetic alloy ribbon 1 is re-wound onto a smaller diameter winding frame 31:I which has been annealed to remove internal strain (stress). That is, by applying a bending stress corresponding to a small bending diameter, a bending stress corresponding to the difference is applied to the wound core 2. In this case, each part of the amorphous magnetic alloy ribbon 1 does not have the complicated and random strain before strain relief annealing, but instead has a large tension on the outside and a large compressive force on the inside, as shown in Figure 2. It is thought that directional stress is acting on the In the amorphous magnetic alloy ribbon 1 with positive (negative) magnetostriction, magnetoelastic anisotropy is induced by tension in parallel to the tension direction (in the case of negative, perpendicular direction), and it is easily magnetized and becomes C. <<] On the other hand,
Magnetoelastic anisotropy is induced by the compressive force in a direction perpendicular to the direction of the compressive force (parallel if it is negative), making it difficult (or easy) to be magnetized.
Become. It is thought that the above-mentioned tendency is particularly remarkable in iron-based amorphous magnetic alloy ribbons that have positive magnetostriction and are highly sensitive to stress. In other words, as shown in the magnetization curve shown in Figure 3 (a), the tension component of the stress makes the magnetization curve perpendicular, and the compressive force component suppresses any further increase in magnetization, thereby exhibiting high squareness. It is presumed that (thin ribbons with negative magnetostriction also exhibit high squareness). Here, (b) is a typical l1 of the sample to which no bending stress was applied after annealing.
It is an lH curve. FIG. 4 shows the characteristics of the wound core manufactured by the method of the present invention. METGLAS manufactured by Allied, USA, has a large positive magnetostriction compared to an amorphous magnetic alloy ribbon.
Using 2605S2 material, it was first cut into a diameter of 10 (1 m).
The core was wound around a winding frame of 400 A/m with a DC magnetic field applied (marked O in the figure) or not applied (marked Δ in the figure), annealing temperature 400°C, annealing time 1 hour, N2 Annealing was performed in gas. After that, it was re-wound onto a winding frame with a diameter of 20 m to 801 m1, and its squareness ratio was examined. The squareness ratio is the ratio between the residual magnetic flux density Br and the (induced) magnetic flux density B1 when the magnetizing force E is tA,/an.

In magnetic field annealing, when no bending stress was applied, the weight was 0999 g''! when rewinding from No. 85 to a 20 m diameter winding frame, and in non-magnetic field annealing, it continuously changed from 64 m to 94%. , it is shown that not only can the squareness ratio be improved, but also that an arbitrary squareness ratio can be selected.

The above example describes the case where the bending diameter before annealing is made large and the bending diameter after annealing is made small. You can also use it as

〔Effect of the invention〕

As explained above, the method for manufacturing a wound core according to the present invention includes:
An amorphous magnetic alloy ribbon with non-zero magnetostriction is annealed to a desired self-diameter and then re-wound to a different desired bending diameter to apply bending stress to the wound core. The squareness of the magnetization curve, which is one of its magnetic properties, can be continuously improved.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a method for manufacturing a wound core according to an embodiment of the present invention, FIG. 2 is an explanatory diagram showing the stress distribution of an amorphous magnetic alloy ribbon subjected to bending stress, and FIG. Figure 4 shows the B-H curve of the sample to which no bending stress was applied after annealing and the B-H curve (a) of the sample to which bending stress was applied. Figure 4 shows the squareness ratio of the wound core and the rewinding. FIG. 3 is a diagram showing the relationship between diameters. In the drawing, 1 is an amorphous magnetic alloy ribbon, 2 is a wound core, 5h,
51:1 indicates the winding frame. (7317) Agent Patent attorney Nori Chika Wl Yu C and 1 other person) Figure 1 Figure 3 Mouth jp+4 Mouth jkl+, i diameter (rnrn)

Claims (1)

[Claims] A method for producing a wound core, characterized in that an amorphous magnetic alloy ribbon having non-zero magnetostriction is annealed to have zero or arbitrary bending diameter, and then re-wound to have a different desired bending diameter. .