JPH04311011A - Manufacture of wound core for transformer - Google Patents

Abstract

PURPOSE:To manufacture a stabilized block body by setting conditions on the bonding agent, to be applied on the surface of cross-section of a thin band, and on the application of the bonding agent in the manufacture process of the core used on the transformer wherein an amorphous magnetic alloy thin band is used, and also to cut down the working manhours. CONSTITUTION:The wound body consisting of an amorphous magnetic alloy thin band 3 is cut, its cross-section is coated with a bonding agent 2 having the viscosity of 100 poise or less when coating and the hardness of 50 or more after hardening. After the wound body has been hardened, it is brought into a block state, and a magnetic core is formed. As a result, the wound body can be sufficiently formed into a block state, and the manhours for manufacture of the magnetic core can be cut down remarkably.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for 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 produced by heating an alloy of metals (iron, cobalt, nickel, etc.) and semimetals (boron, silicon, phosphorus, carbon, etc.) to a molten state, and then quenching it using an ultra-quenching method. The thickness is approximately 25 microns. The material also inherently has excellent magnetic properties. However, in the as-manufactured state, the magnetic properties are poor due to internal strain caused by ultra-quenched cooling, so an annealing treatment is usually performed to obtain the original magnetic properties. Furthermore, when forming the magnetic core of a transformer, there are stacked iron core methods and wound iron core methods.To explain the case of forming the wound iron core applied to relatively small capacity transformers, conventionally silicon steel sheets were used. A manufacturing method using an amorphous magnetic alloy ribbon will be described with reference to FIGS. 4 to 9 regarding the one-turn cut type wound iron core structure that is often employed in the magnetic core of the transformer used.

In the figure, a core 21 is wound with an amorphous magnetic alloy ribbon.
to obtain a wound body 22. Next, after removing the winding core 21, the winding body 22 is cut by tightening with a tightening jig 24 to obtain an assembly 23. After applying the adhesive 25 to one or both of the cut surfaces and curing it, the assembly 23 is divided into blocks 27, which are laminates each consisting of a plurality of ribbons 26. After about 4 to 6 of these blocks 27 are laminated in a ring-shaped core, they are formed into a final core shape to obtain a magnetic core 28. A gap 29 exists approximately in the abutting portion of the block body 27. In addition, in the state of the adhesive 25 applied as described above, as shown in FIG. 8, almost no impregnation of the adhesive 25 between the ribbons 26 is observed.

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

[0005]

[Problems to be Solved by the Invention] In such a conventional manufacturing method, a one-turn cut type amorphous magnetic alloy magnetic core is produced by winding the thin ribbon 26 to produce the wound body 22, and then cutting it. Adhesive 25 is applied to the cut surface and the plurality of thin strips 26 are divided into one block, but if the viscosity of the adhesive 25 is high, it becomes difficult to bond the thin strips 26 to each other.
Blocking becomes insufficient, and the magnetic core 2 after annealing
8, when dividing and assembling each block, a portion of the thin strip 26 may be chipped and fall off. Furthermore, if the hardness of the adhesive 25 is small, it will be difficult to maintain the shape of the magnetic core 28.
It takes a long time to assemble the magnetic core 28 after annealing.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a manufacturing method for improving the workability of the magnetic core manufacturing process.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the first invention of the present application includes the steps of: winding an amorphous magnetic alloy ribbon to form a wound body; and cutting this wound body. , a step of applying an adhesive to the cut surfaces generated by the cutting, and then fixing the alloy ribbons to each other; a step of disassembling the plurality of alloy ribbons constituting the laminate into one block; In a manufacturing method in which blocks are used as the minimum basic unit, they are stacked in a ring shape, formed into a final shape, and then annealed, the adhesive applied to the cut surface has a viscosity of 100 poise or less at the time of application, and is cured. A hardness of 50 or more (JIS-A) is used. In the second invention of the present application, silicone resin is used as the adhesive applied to the cut surface.

[0008]

[Function] As mentioned above, since the viscosity of the adhesive used to block the amorphous magnetic alloy ribbon when applied is 100 poise or less, the adhesive penetrates between the layers of the ribbon to an appropriate extent, allowing the adhesive to form a block between the ribbons. The adhesive strength between the two is improved, making it possible to form blocks in the subsequent process. Furthermore, by setting the hardness of the adhesive to 50 or more, the rigidity of the end of the block is improved and the magnetic core assembly operation becomes easier.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to FIGS. 1 to 3. The steps from winding to cutting, applying adhesive, and forming blocks are the same as conventional ones, and their explanations will be omitted. Figure 1
As shown in the figure, the block body 1 includes four amorphous magnetic alloy ribbons 3.
~20 sheets are laminated to form a block, and adhesive 2 is applied to the cut surfaces. FIG. 2 is a partial schematic sectional view of the end of the block body 1, and suitable compositions for the adhesive 2 include silicone resin, heat-resistant epoxy resin, and heat-resistant polyester resin. Also, the viscosity of adhesive 2 when applying is 10
It is preferable that the poise is less than 0 poise, and if it is more than that, it becomes difficult to penetrate between the tightened ribbons 3, and the desired characteristics cannot be expected. Further, it is necessary that the hardness of the adhesive 2 after curing is 50 or more (JIS-A). If the resin component of the adhesive is an epoxy resin or polyester resin, the hardness can be easily adjusted by selecting the monomer. For example, in the case of epoxy resin, it is based on bisphenol type, and an appropriate amount of inorganic filler is mixed in to improve coating film forming properties and heat resistance.

When a silicone resin is used as the adhesive 2, monomers are limited, so it is difficult to satisfy both the viscosity and the hardness after curing. That is, silicone resin essentially has low hardness, and in order to increase its hardness, a filler such as silica is mixed in. Therefore, the viscosity inevitably increases, making it difficult to satisfy both performances. Further, from the viewpoint of manufacturing requirements, it is preferable that the adhesive 2 is cured at room temperature, and furthermore, from the viewpoint of workability, it is preferable that the pot life at room temperature is long. Adhesive 2 that satisfies these performances has been made possible by mixing an inorganic filler into silicone rubber that hardens at room temperature and diluting it with a solvent such as xylene. Room temperature curing type silicone rubbers include Shin-Etsu Chemical's KE-44, KE-441, and Toray Dow SE-44.
20, SE-4486, etc. After applying the liquid adhesive 2 prepared as above to the cut surface and curing at room temperature, the assembly was divided into blocks, stacked again, and molded with a rectangular core to form the final shape as shown in Figure 3. obtain. In the figure, reference numeral 4 indicates a gap formed between the magnetic cores 5 and the abutting portions of the blocks. Next, the magnetic core is supported by metal fittings and annealed at 300 to 380° C. in an inert gas.

[0011]

As described above, according to the present invention, the viscosity when applied to the cut surface obtained by cutting a wound body produced by winding an amorphous magnetic alloy ribbon is 100 poise or less, Since an adhesive having a hardness of 50 or higher after curing is used, sufficient adhesion between the ribbons is achieved and a stable block body can be manufactured. Furthermore, the rigidity of the end portion of the block body is sufficient, and the magnetic core does not come off due to chipping or the like during assembly work, and work efficiency is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a schematic perspective view of a part of the magnetic core manufacturing process in a method for manufacturing a wound core for a transformer according to an embodiment of the present invention, when four blocks are assembled into an assembly.

[Figure 2] Partial schematic sectional view of the end of the block body

[Figure 3
]Schematic front view of a magnetic core composed of an aggregate of blocks.

[Fig. 4] A schematic front view showing a state in which a ribbon is wound around a winding core in a conventional example.

[Fig. 5] A schematic front view showing the state in which the wound ribbon is tightened with a jig, cut with a cutting machine, and adhesive is applied to the cut surface.

[Fig. 6] A schematic perspective view of a block body formed by stacking multiple thin strips.

[Fig. 7] A schematic perspective view of the same as an assembly of four blocks

[Fig. 8] Partial schematic sectional view of the end of the block body

[Figure 9
]Schematic front view of a magnetic core composed of an aggregate of blocks.

[Explanation of symbols]

1 Block type 2. Adhesive 3 Thin obi 4 Magnetic core 5 Voids

Claims (2)

[Claims] 1. A step of winding an amorphous magnetic alloy thin ribbon to form a wound body, cutting the wound body, and applying an adhesive to the cut surface produced by the cutting, and then cutting the thin ribbon. A process of fixing each other, a process of separating a plurality of thin strips constituting the laminate into one block, and a manufacturing process of laminating the one block into a ring shape using the one block as the minimum basic unit, forming it into a final shape, and then annealing it. A method for manufacturing a wound iron core for a transformer, characterized in that the adhesive applied to the cut surface has a viscosity of 100 poise or less when applied, and a hardness after curing of 50 or more (JIS-A). 2. The method of manufacturing a wound iron core for a transformer according to claim 1, wherein the adhesive applied to the cut surface is silicone resin.