JPH0812834B2 - Method for manufacturing amorphous metal toroidal core - 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 for producing a toroidal core made of an amorphous metal (including a single metal and an alloy) for a magnetic body, and more specifically, a toroidal core made of an annular body of the metal laminate with a small iron loss. The present invention relates to a method of manufacturing a core.

[0002]

2. Description of the Related Art It is known that an amorphous metal is solidified by cooling a molten metal at an extremely high speed without passing through crystallization. For the sake of realizing this cooling, amorphous metal is generally obtained in the form of ribbon, thin film or fine powder.

In particular, amorphous metals for magnetic materials have begun to be used as magnetic materials for electric devices by taking advantage of their excellent magnetic properties. In this case, its thinness also helps prevent heat generation due to eddy currents.

The toroidal core is a ring-shaped iron core (not necessarily iron, but a core made of a ferromagnetic material), which is often used by being housed in a ring-shaped case.

Filling with resin or the like for the purpose of cushioning the space between the iron core and the case has been conventionally performed. However, this method is not intended to improve the magnetic characteristics of the core, nor does it bring about its effect.

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for manufacturing a toroidal core with a very low iron loss in the high frequency range.

[0007]

SUMMARY OF THE INVENTION The present invention provides an electrically insulating and bending strength (ASTM D790) method between each layer constituting an annular laminated body of an amorphous metal for a magnetic material by a vacuum impregnation method or a pressure impregnation method. 1000 kg /
cm ² or less, compressive strength (1 according to ASTM D 695
It is a method for producing a toroidal core having an extremely small iron loss in a high frequency range, which is characterized by interposing a resin or rubber-like material of 1500 kg / cm ² or less (measured at 0% strain point).

Amorphous metals for magnetic materials are permalloy (Fe containing 35 to 80% Ni) far superior to ferrite.
-Ni alloy has a saturation magnetization characteristic equal to or higher than the general term). However, although its iron loss is small, its use in a high frequency magnetic field is still accompanied by considerable heat generation.

In order to solve the problem, studies are being made to improve the composition of the amorphous metal itself, but the present inventors have found that iron loss, which is considered to be unavoidable and which is peculiar to the amorphous core for magnetic materials, is processed. Succeeded in greatly reducing it.

In the toroidal core obtained by the present invention, the resin or rubber-like material interposed between the respective metal layers not only electrically insulates the respective layers from each other, but also substantially deteriorates the magnetic characteristics of the entire core. It also serves to keep it in the case. This function is extremely important for manifesting the effects of the present invention. That is, in the case where the intervening layer requires high temperature curing or causes a large expansion or contraction during curing, distortion is caused in the core, resulting in deterioration of its magnetic characteristics. Therefore, the resin on the soft side is preferable.

Bending strength (ASTM) may be used as the resin having the above-mentioned function, regardless of whether it is a thermoplastic resin or a thermosetting resin.
Measured by D 790) 1000 kg / cm ² or less,
Preferably 800 kg / cm ² or less, and compressive strength (measured at 10% strain point according to ASTM D 695) 1
500 kg / cm ² or less, preferably 1000 kg / c
Any m ² or less that can be a solution of an appropriate organic solvent can be used.

On the other hand, since the rubber-like material is contained in the above-mentioned range of bending strength and compressive strength and can be a solution of an organic solvent, any uncrosslinked or low-crosslinked material can be used. For rubber, spring hardness (JIS A) is usually used instead of measuring bending strength.
The spring hardness of the unvulcanized or partially vulcanized rubber is preferably selected to be 80 or less, more preferably 50 or less.

In the present invention, even if the mixture of the resin and the rubber-like material, the partially crosslinked product thereof, or the mixture of the resin and the partially crosslinked rubber, the bending strength and the compression strength are within the above ranges. Of course, any solution that can be a solution of an organic solvent can be used.

As the resin, for example, polyolefin, modified polyolefin such as halogenated, acrylated or maleic anhydride, ethylene-vinyl acetate copolymer, (meth)
Acrylic resin, ABS resin, SB block copolymer resin, polyester resin, polyethylene terephthalate resin, polybutylene terephthalate resin, etc., polyamide resin, polycarbonate resin, soft epoxy resin, soft polyurethane, soft silicone resin and mixtures thereof. You can

Examples of the rubber-like material include olefin rubbers such as ethylene-α-olefin copolymer and propylene-
α-olefin copolymer, ethylene-α-olefin-
Non-conjugated diene terpolymer, natural rubber, polybutadiene rubber, polyisoprene rubber, butyl rubber, SBR, N
Mention may be made of BR, chloroprene rubber and mixtures thereof. Mixtures of the above resins and rubber may also be used.

In order to manufacture a toroidal core according to the present invention, it is necessary to interpose a material that is electrically insulating and does not cause strain in the core between the metal layers forming the core. The substance is a resin, a rubber-like substance or a mixture thereof as described above, and the means for interposing them is preferably a vacuum impregnation method or a pressure impregnation method. That is, not only are the gaps between the metal layers forming the core extremely small, but air or moisture may be present in the gaps. Therefore, as a means for forcibly removing them and introducing the intervening substance, a vacuum is used. The impregnation method or the pressure impregnation method gives good results. Usually, it is sufficient to use either the vacuum impregnation method or the pressure impregnation method, but they may be used together if necessary.

[0017]

Examples (Examples 1 to 3 and Comparative Examples 1 to 3) Width 5 m
Vacuum deaeration of a toroidal core having a thickness of about 5 mm formed by laminating amorphous magnetic material foils having a thickness of 20 to 30 μm,
This is an industrial gasoline solvent naphtha solution of polyester resin [resin content concentration (105 ° C., 3 hr) 40 ± 3%,
Specific gravity (25 ° C) 0.94 ± 0.02, viscosity 1.5-3.
It was immersed in a vacuum degassed product of 5 cp] to impregnate the solution between the metal ribbons.

The impregnated core was naturally dried at room temperature to form a film, and the target toroidal core was obtained. The flexural strength of this polyester resin after drying (measured by ASTM D 790) is 500 kg / cm ² , and the compressive strength (ASTM).
Measured at 10% strain point according to D 695) is 730 kg /
cm ² .

The three cores thus obtained have 50 cores.
A winding of turns is applied, and the magnetic flux density is 10 at a frequency of 50 kHz.
The iron loss at 00 Gauss (G) and 3000 Gauss was measured. The results are shown in Table 1. The measurement results under the same conditions for the core before impregnation are also shown in the same table.

[0020]

[Table 1] *: The iron loss is indicated by a value per 15 g (Watt).

From Table 1, at both magnetic flux densities, the iron loss after impregnation (Example) is about 1 as compared to before impregnation (Comparative Example).
It can be seen that the value is decreased to / 2 (the magnetic characteristics are improved).

Example 4 Width 5 mm, Thickness 20-30 μ
thickness of about 5 m
The toroidal core of m was vacuum degassed, and an ethylene-propylene copolymer (ethylene content 80 mol%, Mooney viscosity ML _{1 + 4} (100 ° C.) = 10) in an industrial benzene solution (polymer concentration 40 wt%) was used. ), And the solution was permeated between the metal layers. The spring hardness of this rubber layer was 40 and the compressive strength was 20 kg / cm ² .

The impregnated core was taken out and naturally dried at room temperature to form a film, and the iron loss was measured under the same conditions as in Examples 1 to 3. Magnetic flux density 1000 gauss (G) and 3000
The voltage and current applied to the winding in Gauss are 23.
At 8V, 5.8mA and 71.8V, 17.5mA,
The iron loss per 15 g was 0.070 watts (W) and 0.68 watts, respectively.

[0024]

As described above, according to the manufacturing method of the present invention, an amorphous metal toroidal core with extremely low iron loss in the high frequency range can be obtained.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication location H01F 27/24 (56) Reference JP-A-57-10916 (JP, A) JP-A-58- 50713 (JP, A) JP 57-187916 (JP, A) JP 57-106011 (JP, A) JP 58-56305 (JP, A) JP 58-148413 (JP, A) JP-A-59-181007 (JP, A)

Claims (1)

[Claims] 1. An electrically insulating and bending-strength (ASTMD 790) layer between layers forming an annular laminate of an amorphous metal for a magnetic body is formed by a vacuum impregnation method or a pressure impregnation method.
1000 kg / cm ² or less, compressive strength (A
Measured at 10% strain point according to STM D695) 1500k
A method for producing a toroidal core having an extremely low iron loss in a high frequency range, characterized by interposing a resin or rubber-like material having a g / cm ² or less.