JP2584141B2 - Manufacturing method of wound iron core for transformer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a wound iron core used in a transformer using an amorphous magnetic alloy ribbon.

[0002]

2. Description of the Related Art In recent years, amorphous magnetic alloy ribbons have been studied as magnetic core materials for transformers and the like. Amorphous magnetic alloy ribbons are heated to an alloy consisting of a metal (iron, cobalt, nickel, etc.) and a semi-metal (boron, silicon, phosphorus, carbon, etc.) and brought to a molten state, which is quenched by a super-quenching method. It is about 25 microns thick. Also, the material has essentially excellent magnetic properties. However, the as-prepared state has poor magnetic properties due to the presence of strain inside due to ultra-quenching, so that annealing is usually performed to obtain the original magnetic properties. Furthermore, when using as a magnetic core of a transformer, there are a piled iron core type and a wound iron core type, and a case of forming a wound iron core applied to a relatively small capacity transformer will be described. Referring to FIGS. 4 to 9, a description will be given of a manufacturing method using an amorphous magnetic alloy ribbon with respect to a one-turn cut wound iron core structure which is often used for a magnetic core of a transformer used.

In the figure, an amorphous magnetic alloy ribbon is
And a wound body 22 is obtained. Next, after the core 21 is removed, the winding body 22 is cut by fastening with a fastening jig 24 to obtain an aggregate 23. After applying and curing the adhesive 25 on one or both of the cut surfaces, the assembly 23 is divided into block bodies 27 of a laminated body composed of a plurality of thin strips 26. Then, after about 4 to 6 of these block bodies 27 are laminated with a ring-shaped core, the magnetic core 28 is obtained by molding into a final core shape. A gap 29 is generally present in the butted portion of the block body 27. In the above-described state of the application of the adhesive 25, the impregnation of the adhesive 25 between the thin strips 26 is hardly recognized as shown in FIG.

[0004] The molded magnetic core 28 is annealed in a magnetic field,
Thereafter, the magnetic core 28 is disassembled into each block body 27 and inserted into a coil to assemble and manufacture the magnetic core 28.

[0005]

In such a conventional manufacturing method, a one-turn-cut amorphous magnetic alloy core is wound around the ribbon 26 to form a wound body 22 and then cut. An adhesive 25 is applied to the cut surface, and a plurality of the thin strips 26 are divided into one block. When the viscosity of the adhesive 25 is high, adhesion between the thin strips 26 becomes difficult,
Blocking becomes insufficient, and the magnetic core 2 after annealing
At the time of dividing and assembling each block, the thin strip 26 may be partially missing and fall off. If the hardness of the adhesive 25 is small, it is difficult to maintain the shape of the magnetic core 28,
It takes a long time to assemble the magnetic core 28 after annealing.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a manufacturing method for improving workability in a magnetic core manufacturing process.

[0007]

In order to achieve the above object, according to a first aspect of the present invention, a step of winding a thin ribbon of an amorphous magnetic alloy to form a roll, cutting the roll, Applying an adhesive to a cut surface generated by the cutting, and then fixing the alloy ribbons to each other; and disassembling a plurality of alloy ribbons constituting the laminate as one block. In a manufacturing method in which the blocks are laminated as a minimum basic unit, formed into a ring shape and molded into a final shape, and then subjected to an annealing treatment, the adhesive applied to the cut surface has a viscosity at the time of application of 100 poise or less and is cured. Later hardness of 50 or more (JIS-A) is used. In the second invention of the present application, a silicone resin is used as an adhesive applied to the cut surface.

[0008]

As described above, the viscosity of the adhesive for blocking the amorphous magnetic alloy ribbon at the time of application is 100 poise or less. The adhesive force between them is improved, and it is possible to sufficiently block in a later step. Further, by setting the hardness of the adhesive to 50 or more, the rigidity of the end portion of the block is improved, and the work of assembling the magnetic core becomes easy.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. The steps from the winding step to the cutting, the application of the adhesive, and the blocking are the same as those in the related art, and the description is omitted. FIG.
As shown in FIG.
Approximately 20 sheets are laminated and made into a block, and the adhesive 2 is applied to the cut surface. FIG. 2 is a schematic cross-sectional view of a part of the end of the block body 1. As the composition of the adhesive 2, a silicone resin, a heat-resistant epoxy resin, a heat-resistant polyester resin, or the like is suitable. The viscosity of the adhesive 2 at the time of application is 10
If the polish is not more than 0 poise, it is difficult to penetrate between the tightened ribbons 3 and desired characteristics cannot be expected. Further, the hardness of the adhesive 2 after curing must be 50 or more (JIS-A). The hardness can be easily adjusted by selecting the monomer when the resin component of the adhesive is an epoxy resin or a polyester resin. For example, in the case of an epoxy resin, a bisphenol type is used as a base, and an appropriate amount of an inorganic filler is mixed in order to improve the film forming property and heat resistance.

When a silicone resin is used as the adhesive 2, it is difficult to satisfy both the properties of the viscosity and the hardness after curing because the monomer is limited. That is, the silicone resin is essentially low in hardness, and a filler such as silica is mixed to increase the hardness. Therefore, the viscosity naturally increases, and it is difficult to satisfy both performances. Further, the curing treatment of the adhesive 2 is preferably performed at room temperature in view of manufacturing requirements, and it is preferable that the pot life at room temperature is long from the viewpoint of workability. As an adhesive 2 that satisfies these performances, it became possible by mixing an inorganic filler into a room temperature curing type silicone rubber and diluting it with a solvent such as xylene. As room temperature curing type silicone rubber, Shin-Etsu Chemical's KE-44, KE-441, Toray Dow SE-44
20, SE-4486, and the like. After applying the liquid of the adhesive 2 adjusted as described above to the cut surface and curing at room temperature, the aggregate is divided into blocks, re-laminated, and molded with a rectangular core to obtain a final shape as shown in FIG. obtain. In the figure, reference numeral 4 denotes an air gap formed in the butted portion of the magnetic core 5. Next, the magnetic core is supported by metal fittings and annealed in an inert gas at 300 to 380 ° C.

[0011]

As described above, according to the present invention, the viscosity at the time of application is 100 poise or less on a cut surface formed by cutting a wound body formed by winding an amorphous magnetic alloy ribbon. Since an adhesive having a hardness of 50 or more after curing is used, the bonding between the ribbons is sufficiently performed, and a stable block body can be manufactured. Further, the rigidity of the end portion of the block body is sufficient, and the workability is remarkably improved without falling off due to chipping or the like at the time of assembling the magnetic core.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing a case where four block bodies are assembled in a part of a magnetic core manufacturing process in a method of manufacturing a transformer core according to an embodiment of the present invention.

FIG. 2 is a partial schematic cross-sectional view of an end of the block body.

FIG. 3 is a schematic front view of a magnetic core constituted by an aggregate of block bodies.

FIG. 4 is a schematic front view showing a state where a ribbon is wound around a core in a conventional example.

FIG. 5 is a schematic front view showing a state in which the wound ribbon is tightened by a jig, cut by a cutting machine, and an adhesive is applied to the cut surface.

FIG. 6 is a schematic perspective view of a block body in which a plurality of thin ribbons are stacked to form a block.

FIG. 7 is a schematic perspective view of the same four-body aggregate.

FIG. 8 is a partial schematic cross-sectional view of an end portion of the block body.

FIG. 9 is a schematic front view of a magnetic core constituted by an assembly of block bodies.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Block body 2 Adhesive 3 Thin ribbon 4 Magnetic core 5 Air gap

 ────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiromitsu Hara 1006 Kazuma Kadoma, Kadoma City, Osaka Inside Matsushita Electric Industrial Co., Ltd.

Claims (2)

(57) [Claims] 1. A step of winding a ribbon of an amorphous magnetic alloy to form a wound body, cutting the wound body, and applying an adhesive to a cut surface generated by the cutting. A step of fixing each other, a step of separating a plurality of thin strips constituting the laminate as one block, a step of stacking the one block as a minimum basic unit in a ring shape, forming a final shape, and then annealing. In the method, the adhesive applied to the cut surface has a viscosity of 100 poise or less at the time of application and a hardness after curing of 50 or more (JIS-A). 2. The method according to claim 1, wherein the adhesive applied to the cut surface is a silicone resin.