Method for manufacturing a coiled magnetic core, and coiled magnetic core

Abstract

To provide a manufacturing method of a wound magnetic core capable of improving the insulation between thin bands of a wound magnetic core formed as an annular wound body by winding a soft magnetic metal thin band, and a wound magnetic core.SOLUTION: A non-magnetic and insulating metal oxide powder is adhered to the surface of a soft magnetic metal thin band of an amorphous structure, and is wound in a ring shape to form a winding body in which a metal oxide powder is interposed between the thin bands, and after the winding body is heat-treated in a non-oxidizing atmosphere, the winding body is subjected to oxide film forming treatment in an oxidizing atmosphere adjusted to a temperature lower than that of the heat treatment, the surface of the soft magnetic metal thin band is oxidized, and a resin is impregnated between the thin bands of the winding body and cured, and the metal oxide powder is fixed.SELECTED DRAWING: Figure 1

Claims

1. A method for manufacturing a wound magnetic core, wherein a thin strip of soft magnetic metal is wound around it, forming a winding body with multiple layers stacked in the winding diameter direction, A first step involves attaching a non-magnetic, insulating metal oxide powder to the surface of a soft magnetic metal thin strip with an amorphous structure. A second step is to wind the soft magnetic metal strip in a ring shape to obtain a rolled body in which the metal oxide powder is interposed between the strips. A third step involves heat-treating the aforementioned coil in a non-oxidizing atmosphere, A fourth step is performed after the third step, in which an oxide film formation treatment is carried out on the rolled body at a temperature lower than the heat treatment temperature of the third step and in an oxidizing atmosphere, thereby oxidizing the surface of the soft magnetic metal thin strip. The process includes a fifth step, after the fourth step, in which resin is impregnated between the thin strips of the rolled body and cured. In the first step, the soft magnetic metal strip is immersed in a suspension containing the metal oxide powder, and the suspension adhering to one surface of the soft magnetic metal strip after it is removed from the suspension, thereby reducing the amount of metal oxide powder adhering to the strip to 0.1% or more and 1.2% or less by weight ratio of the metal oxide obtained by the following formula (1). Weight ratio of metal oxide (%) = (Weight of metal oxide attached to soft magnetic metal strip / Weight of soft magnetic metal strip) × 100 ... (1) The metal oxide is MgO, and the amount of metal oxide powder attached is 0.1 × 10⁻⁶. －３ kg / m ２ The above is 1.5 x 10 －３ kg / m ２ The following: The average particle size of the metal oxide powder is 0.5 μm or more and 1.0 μm or less. Between the thin strips of soft magnetic metal, the metal oxide powder is interposed and impregnated with resin, and the packing density is 65% or more and 75% or less. The aforementioned space factor is obtained by the following equation (2): Space factor = [(We / ρ) / {(OD 2 - ID 2 ) x HT x π / 4}] x 100 (%) ... (2) Here, We: Weight of the rolled material after oxidation layer formation (g) ρ: Density of soft magnetic metal thin strip (g / cm³) OD: Outer diameter of the roll after oxide layer formation (cm) ID: Inner diameter of the roll after oxidation layer formation (cm) HT: Height of the rolled material after oxidation layer formation (cm) This is a method for manufacturing a coiled magnetic core.

2. The method for manufacturing a wound magnetic core according to claim 1, wherein the third step is a heat treatment A for depositing nanocrystals on the amorphous soft magnetic metal thin strip, or a heat treatment B for stress relaxation of the amorphous soft magnetic metal thin strip.

3. A wound magnetic core in which a thin strip of soft magnetic metal is wound, The coil is constructed by stacking multiple layers in the direction of the winding diameter. The soft magnetic metal thin strip has an amorphous or nanocrystalline structure. The surface of the soft magnetic metal thin strip has an oxide layer of Fe derived from the metal constituting the soft magnetic metal thin strip. A non-magnetic, insulating metal oxide powder is interposed between the aforementioned soft magnetic metal thin strips. The amount of metal oxide powder adhering to one surface of the soft magnetic metal strip is less than the amount of metal oxide powder adhering to the other surface of the soft magnetic metal strip, and the amount of metal oxide powder adhering is set to 0.1% or more and 1.2% or less by weight ratio of the metal oxide obtained by the following formula (1). Weight ratio of metal oxide (%) = (Weight of metal oxide attached to soft magnetic metal strip / Weight of soft magnetic metal strip) × 100 ... (1) The metal oxide is MgO, and the amount of metal oxide powder attached is 0.1 × 10⁻⁶. －３ kg / m ２ The above is 1.5 x 10 －３ kg / m ２ The following: The average particle size of the metal oxide powder is 0.5 μm or more and 1.0 μm or less. Between the thin strips of soft magnetic metal, the metal oxide powder is interposed and impregnated with resin, and the packing density is 65% or more and 75% or less. The aforementioned space factor is obtained by the following equation (2): Percentage ratio = [(We / ρ) / {(OD)] ２ -ID ２ )×HT×π / 4]×100(%) ・・・(2) Here, We: Weight of the rolled material after oxidation layer formation (g) ρ: Density of soft magnetic metal thin strip (g / cm³) ３ ) OD: Outer diameter of the roll after oxide layer formation (cm) ID: Inner diameter of the roll after oxidation layer formation (cm) HT: Height of the rolled material after oxidation layer formation (cm) That is, a wound magnetic core.

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