JPS6182412A - Manufacture of wound core - Google Patents

Abstract

PURPOSE:To obtain a wound core of high quality with simple steps by coating a thin amorphous magnetic alloy strip with resin, winding the strip coated with the resin to form the core, and heat treating it. CONSTITUTION:Since the steps of coating resin is executed in the state that a thin amorphous magnetic alloy strip 1 is developed, resin 3 can be uniformly, readily and effectively coated over the entire necessary portion. The resin 3 coated on the strip 1 is dried, wound on a winding die 4 by a winding machine to form a circular winding core 2. Then, the core 2 is filled in a heating furnace to remove a distortion, and heat treated. Thus, the distortion is removed, and the core 2 is heat treated to remove the distortion of the strip 1 to provide excellent magnetic properties, the thin strip layers are effectively secured integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a wound core formed by winding an amorphous magnetic alloy ribbon.

[Technical background of the invention and its problems]

Small-sized wound cores are used in switching power supplies for electronic circuits, and recently, a type of seed-wound core in which a thin ribbon of amorphous magnetic alloy is wound is being developed.

Amorphous magnetic alloy ribbons are manufactured by cooling molten alloys at ultra-high speeds, and have excellent magnetic properties with low iron loss. Fe-based and C0-based materials are used as the core material. Enter.

When manufacturing a wound core made of amorphous magnetic alloy ribbon, the following method is used. First, an amorphous magnetic alloy ribbon is wound around a wound layer to form a wound core. Next, the formed wound core is subjected to strain relief heat treatment. This heat treatment removes the strain that occurred in the amorphous magnetic alloy ribbon during its manufacture, and restores the magnetic properties of the ribbon that had deteriorated due to this strain. Next, the wound core is impregnated with a resin, and a resin such as epoxy resin is impregnated between the layers of the wound amorphous magnetic alloy ribbon, and then the resin is heated and hardened to fix each ribbon layer to each other.

Furthermore, the wound core is heat treated in a magnetic field.

This heat treatment removes the distortion and improves the magnetic properties, since the amorphous magnetic alloy ribbon is subjected to the hardening contraction force of the resin during the resin curing process, causing distortion and deteriorating the magnetic properties.

However, in such a method of manufacturing a wound core, each treatment of strain relief heat treatment, resin hardening treatment, and heat treatment in a magnetic field is performed, so the number of steps is large and manufacturing of the wound core is troublesome. In addition, in order to fix the wound core, the wound core around which the amorphous magnetic alloy ribbon is wound is impregnated with resin, so that the resin is evenly distributed throughout the gap between each ribbon layer on the wound core. Therefore, it is difficult to securely bond the entire ribbon layers to each other with resin and to integrate the wound core into one piece.

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and an object of the present invention is to provide a method for manufacturing a wound core that has a simple manufacturing process and can yield a high-quality wound core made of an amorphous magnetic alloy ribbon. .

[Summary of the Invention] The method for manufacturing a wound core according to the present invention includes a step of applying a resin to an amorphous magnetic alloy ribbon, and a step of winding the amorphous magnetic alloy ribbon coated with the resin to form a wound core. The method is characterized by comprising a step of heat-treating the wound core.

The manufacturing method of the present invention will be explained with reference to FIGS. 1 and 2.

First, as shown in FIG. 1, a resin 3 is applied to the surface of an amorphous magnetic alloy ribbon 1 used to form a wound core. The resin 3 is applied over one or both sides of the length of the amorphous magnetic alloy ribbon 1 necessary for forming the wound core. The resin 3 to be applied is an inorganic polymer, an epoxy type, a polynistyl type, a butadiene type, etc., and inorganic polymers are particularly preferred in terms of heat resistance. In order to apply the resin 3 to the amorphous magnetic alloy ribbon 1, there are methods such as using a brush or passing the amorphous magnetic alloy ribbon 1 through liquid resin.

This resin coating process is performed with the amorphous magnetic alloy ribbon 1 in an expanded state before forming the wound core.
The resin 3 can be applied uniformly over the entire required portion of the amorphous magnetic alloy ribbon 1 easily and reliably.

Note that the resin 3 applied to the amorphous magnetic alloy ribbon 1 is dried.

Next, as shown in FIG. 2, the amorphous magnetic alloy ribbon 1 is wound around a winding die 4 using a winding machine to form, for example, a circular wound core 2. When the amorphous magnetic alloy ribbon 1 is wound, the resin 3 applied to the ribbon 1 is located between each ribbon layer.

Next, the wound core 2 is placed in a heating furnace and subjected to strain relief heat treatment at a zero heat treatment temperature of approximately 300 to 500°C. This heat treatment removes the strain generated in the amorphous magnetic alloy ribbon 1 in the wound core 2 during its manufacture. Further, by this heat treatment, the resin 3 applied to the amorphous magnetic alloy ribbon 1 is heated and hardened, and each ribbon layer in the wound core 1 is fixed to each other. In this case, since the resin 3 is uniformly applied over the entire ribbon 1, each ribbon layer of the entire wound core 1 is firmly fixed. In this way, in this heat treatment step, by heating the wound core 1, the strain relief heat treatment and the resin hardening treatment can be performed at the same time.

Note that when the resin 3 hardens and shrinks, the amorphous magnetic alloy ribbon 1
is subjected to the curing and shrinking force of the resin 3 (which causes distortion. However, in the strain relief heat treatment, in order to remove the strain that occurred during the production of the amorphous magnetic alloy ribbon 1, the temperature at which the resin 3 hardens and shrinks is Since ribbon 1 is heated at a higher temperature (400°C), resin 3
The strain caused in the ribbon 1 by the curing shrinkage force is removed together with the strain. Therefore, there is no need to perform special heat treatment in a magnetic field as in the past in order to remove the strain caused in the ribbon 1 due to curing and shrinkage of the resin 3. The distortion of the amorphous magnetic alloy ribbon 1 is removed, the amorphous magnetic alloy ribbon 1 has excellent magnetic properties, and each ribbon layer is firmly fixed and integrated into a single piece. .

After the strain relief heat treatment, for example, the wound core 2 is cut and divided, and the windings are assembled to each of the divided wound cores 2. In this case, even if the wound core 2 is cut, it is firmly fixed. Each thin dishun will not separate and open.

[Embodiments of the invention]

Thickness 20μm, width 10! A cobalt-based amorphous magnetic alloy ribbon of IEI was passed through a liquid inorganic polymer, and the inorganic polymer was applied to both sides of the ribbon. Next, after drying the applied inorganic polymer, the amorphous magnetic alloy ribbon was wound to form a circular wound core with an outer diameter of 5 Qm, an inner diameter of 3 Qa, and a height of 10 fi. Thereafter, the wound core was heat treated at a temperature of about 450° C. for 60 minutes. Through this heat treatment, the inorganic polymer coated on the ribbon of the wound core was cured, and each ribbon layer was firmly fixed as a whole. Further, after the heat treatment, the core loss of the wound core was measured and found to be very small at 2 to 3 KG and 150 Km. In addition, when the wound core was cut and divided in order to combine the windings with the wound core, the cut surface of the cut wound iron core did not widen and was stable.

〔Effect of the invention〕

As explained above, according to the present invention, the strain relief heat treatment process and the resin curing process can be performed in one heat treatment, and the magnetic field heat treatment process after the resin curing process can be omitted, thereby simplifying the manufacturing process. Furthermore, it is possible to obtain a high-quality wound core in which each ribbon layer is firmly fixed by uniformly coating the entire amorphous magnetic alloy ribbon with the resin.

[Brief explanation of the drawing]

FIG. 1 and FIG. M2 are explanatory diagrams showing an example of the steps in the manufacturing method of the present invention. 1...Amorphous magnetic alloy ribbon, 2...Wound iron core, 3...
·resin.

Claims (2)

[Claims] (1) A step of applying a resin to an amorphous magnetic alloy ribbon, a step of winding the resin-coated amorphous magnetic alloy ribbon to form a wound core, and a step of heat-treating this wound core. A method for manufacturing a wound iron core, comprising: (2) The method for manufacturing a wound core according to claim 1, wherein the resin applied to the amorphous magnetic alloy ribbon is an inorganic polymer.