JPS63115313A - Manufacture of core using amorphous magnetic alloy thin strip laminated plate - Google Patents

Abstract

PURPOSE:To reliably obtain ultra-low iron loss and high permeability of the title core by a method wherein the core is made thicker by laminating and adhering an amorphous alloy thin strip using a bonding agent having low heat-resisting temperature, and after the above-mentioned thick plate has been formed into a core, it is annealed in a magnetic field. CONSTITUTION:A plurality of amorphous magnetic alloy thin strips are adhered using a bonding agent having the heat-resisting temperature of 300 deg.C or below, and the obtained laminated plate is formed into a wound core type or a stacked type core. Then, an annaling treatment is performed thereon at the temperature range between the heatresisting temperature or above of said bonding agent and the crystallizing temperature or below of the amorphous magnetic alloy thin strip. Pertaining to the bonding agent, a bonding agent of low heat-resisting property which will easily be decomposed by heat or evaporated in the annealing process ordinarily performed in the temperature range of 300-400 deg.C is used. As a result, even when a distortion is generated inside the core on which a winding work is finished, stress is alleviated in a ribbon in association with the vanishment of the bonding agent, and then the formation of magnetic induction anisotropy makes progress. As a result, no distortion remains in the core finally, and excellent magnetic characteristics can be secured.

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an advantageous method for manufacturing a core using a laminated plate made by laminating a plurality of amorphous magnetic alloy ribbons with excellent magnetic properties. be.

(Prior Art) Amorphous alloy ribbons, especially Fe-B-St-based amorphous alloys, have excellent soft magnetism, and also have relatively high saturation magnetic flux density and extremely low core loss. It is being put into practical use as an iron core material for electric quadrants and other devices.

Such amorphous magnetic alloy ribbons (hereinafter simply referred to as ribbons) are normally used as a single plate without gluing to make wound cores or stacked cores and assemble them into transformers. In other words, since the ribbon thickness is considerably thinner than conventionally used silicon steel plates, it has the disadvantage that the number of man-hours required for lamination processing increases.

Efforts have been made to eliminate this drawback, such as increasing the thickness of the ribbon, but it has been reported that this leads to deterioration of iron loss.

In this regard, if multiple ribbons can be pasted together, the number of lamination steps can be significantly reduced. Methods have been proposed in which the cores are produced by combining, drying and solidifying, then shearing and stacking, or winding.

(Problems to be Solved by the Invention) However, in the prior art as described above, the adhesive is applied uniformly to the entire surface of the ribbon and is sufficiently solidified, so that when forming the ribbon by winding it many times, However, there remained a problem in that non-uniform stress was applied to the ribbon due to the restraint by the adhesive layer, leading to deterioration of magnetic properties.

In addition, when ribbons are generally used as magnetic materials, annealing in a magnetic field at a temperature below the Curie point is essential in order to release the internal strain introduced during ultra-quenching and align the magnetic domains. However, in the case of bonding with a heat-resistant adhesive, not only is the heat-resistant adhesive expensive, but also the adhesive strength is maintained even after annealing, resulting in the difference in the coefficient of thermal expansion between the ribbon and the adhesive. As a result, distortion was introduced to the ribbon side during the cooling process, which tended to deteriorate iron loss.

The present invention advantageously solves the above-mentioned problems by reducing the number of man-hours during core forming such as winding and stacking, and also performs annealing in a magnetic field after assembling the core without causing deterioration of magnetic properties. The purpose is to propose an advantageous manufacturing method for cores that can be manufactured by:

(Means for solving problems) First, the background to the elucidation of this invention will be explained.

This invention was born from a re-examination of problems in the prior art. In other words, in order to reduce the number of processing steps when forming an amorphous alloy ribbon into a core, it is an easy and industrially advantageous method to make the plate thicker by laminating and adhering it prior to forming. be. Furthermore, after forming into a core, annealing in a magnetic field is essential in order to demonstrate its original performance.

Conventionally, the main problem has been the use of heat-resistant adhesives that can withstand such annealing, which has resulted in distortion remaining in the ribbon after annealing, causing deterioration of magnetic properties.

Therefore, the inventors changed their thinking and proceeded with their research based on the idea that adhesion between the ribbons was not necessary after being molded and assembled into a core, and that it was actually harmful to the magnetic properties. In other words, we aimed for a method in which the materials are bonded in processes where the number of man-hours is an issue, such as winding and stacking, but the bonding is stopped after the core is integrated.

This was achieved using an extremely simple method of gluing the ribbons together using an adhesive with a low heat resistance, and the core thus obtained exhibited significantly superior magnetic properties compared to conventional materials.

This invention is based on the above knowledge.

That is, this invention involves forming a laminate obtained by bonding a plurality of amorphous magnetic alloy ribbons with an adhesive with a heat resistance temperature of 300°C or less into a wound core or stacked core, The above is a method for manufacturing a core using an amorphous magnetic alloy ribbon laminate, which comprises annealing the amorphous magnetic alloy ribbon in a temperature range below the crystallization temperature thereof.

In this invention, the adhesive used is an adhesive with low heat resistance that easily thermally decomposes or volatilizes during the annealing process, which is usually carried out at a temperature range of 300 to 400 degrees Celsius, in order to improve the magnetic properties of the ribbon. As such adhesives, organic resins such as phenolic resins, polyvinyl acetate systems, epoxy resins, vinyl acetate copolymer systems, and acrylic resins are particularly advantageously suitable.

In this regard, poly(phenylene) oxide, poly(P
-xylylene), aromatic polysulfone, aromatic polyamideimide, polyesterimide, and aromatic polyimide resins are preferred because they remain between the ribbon layers even when annealed at around 350°C, causing residual distortion in the ribbon. do not have.

This invention will be explained in detail below.

In producing the ribbon, any conventionally known liquid quenching method such as a single roll method or a twin roll method can be used.

A typical ribbon thickness of 20 to 40 μm is preferred. Apply adhesive to one side of this ribbon, stack the other ribbon, and press down lightly. A coating amount of 0.1 to 3 .mu.m is sufficient and will not be unnecessarily thick. Eventually, the adhesive will thermally decompose and disappear, so although the harm of being too thick does not appear directly, it is not only disadvantageous in terms of cost, but also tends to reduce the space factor. So I don't like it. The coating amount after dry assimilation is 2 thickness.
It is desirable that the thickness be less than μm, preferably about 1 μm or less. Furthermore, although bonding using an adhesive is generally performed by applying an adhesive as uniformly as possible and pasting, the bonding in the present invention may be performed by bonding only a partial surface of the ribbon. In other words, it is sufficient that the adhesive strength is strong enough to prevent separation during shearing, winding, and stacking. Limiting the use of adhesives in this way is extremely effective in reducing costs.

In manufacturing a laminate according to the present invention, the process of repeatedly applying adhesive to one side of one ribbon, stacking other ribbons, and pressing them together is basically repeated. It is also possible to apply adhesive to multiple ribbons at the same time, and pressure bonding can be completed in one time.

As the crimping method, a method of applying light pressure using a pressure press or a crimping roll is suitable.

The subsequent drying does not necessarily need to be carried out at a high temperature, and may be carried out at a temperature ranging from room temperature to 300°C or less. Depending on the type of adhesive, it may take a long time to dry at room temperature.
Final solidification is performed after winding into a coil, so there is no particular problem.

Then, annealing is performed, but in the case of adhesives that are not heat resistant, even if distortion is caused in the core after winding, the adhesive will be As it disappears, stress relaxation and then the formation of magnetically induced anisotropy proceed within the ribbon, so that finally, no strain remains within the core, thus achieving excellent magnetic properties, i.e., ultra-low core loss and high permeability. Therefore, it is possible to secure the magnetic property.

(Example) Example I Width: 1 cm, thickness: 25 μm Fe7aB+ zsiq
One side of the ribbon with c1 composition has an average thickness of 0 after drying and solidification.
．． An adhesive mainly composed of polyvinyl acetate resin was applied to the ribbon to a thickness of 3 μm, air-dried at 80° C. for 1 minute, and then another ribbon was layered on top of the other ribbon, which was then crimped with a roll. Then, it was left as it was at room temperature for 2 hours to form a laminate. This laminate did not peel off even when cut with a cutting machine.

Thereafter, this laminate was formed into a toroidal core with a diameter of 5 cm, and the laminate was formed into a toroidal core with a diameter of 5 cm.
C. for 1 hour and then cooled.

The iron loss of the amorphous alloy toroidal core thus obtained is W
ll/So was 0.10W/kg.

On the other hand, when polyimide amide, which is a heat-resistant organic resin, was used as an adhesive according to the conventional method, the core loss WI3150 of the amorphous alloy toroidal core was 0.19 W/kg.

Example 2 Width: 1 cm, thickness: 24 μm Fe7eB+oSi+z
An adhesive mainly composed of phenolic resin was applied in dots on one side of the ribbon of the composition so that the average thickness between the eyebrows after drying and solidification was 0.1 μm, and the adhesive was air-dried at about 90°C for 1 minute. Thereafter, the five sheets were stacked together and pressed together with a roll to form a laminate.

Thereafter, this laminate was formed into a toroidal core having a diameter of 6 marks, annealed at 400° C. for 11 hours in a vacuum, and cooled.

Iron loss of the amorphous alloy toroidal core thus obtained −+
37. . was 0.12 匈/kg.

(Effects of the Invention) Thus, according to the present invention, multiple ribbons can be bonded together without deteriorating the magnetic properties of the amorphous magnetic alloy ribbon, and the number of man-hours required for winding and stacking can be significantly reduced. Furthermore, the magnetic properties do not deteriorate even during annealing after core forming, making it suitable for use in power transformers and high frequency transformers.

Claims (1)

[Claims] 1. A laminate obtained by bonding a plurality of amorphous magnetic alloy ribbons with an adhesive with a heat resistance temperature of 300°C or less is formed into a wound core or stacked core, and then the adhesive over the heat-resistant temperature of
A method for producing a core using an amorphous magnetic alloy ribbon laminate, the method comprising performing an annealing treatment in a temperature range below the crystallization temperature of the amorphous magnetic alloy ribbon. 2. The method according to claim 1, wherein the annealing treatment is performed under the application of a magnetic field.