JPS6030103A - Amorphous alloy wound core and manufacture of the same - Google Patents

Abstract

PURPOSE:To obtain an amorphous alloy wound core with excellent magnetic characteristics by a method wherein an amorphous alloy thin strip is wound in the direction of heat-treatment and an insulating film is inserted between the winding layers. CONSTITUTION:An amorphous alloy thin strip 20 is wound in the direction with which it is subjected to heat-treatment and an insulating film 21 which insulates between the winding layers of the amorphous alloy thin strip 20 is inserted between the winding layers. The 1st winding body 1 is formed by winding the amorphous alloy thin strip 20 in such a manner that its 1st end becomes inside and 2nd end 1a comes outside. The 1st winding body 1 is subjected to heat-treatment and then, while the insulating film 21 is provided on the amorphous alloy thin strip 20, the 2nd winding body 24 is formed by winding the amorphous alloy thin strip 20 and the insulating film 21 in such a manner that the 1st end 1b comes inside and the 2nd end 1a comes outside. Then the inside diameter of the 2nd winding body 24 is made practically identical to the inside diameter of the 1st winding body 1.

Description

DETAILED DESCRIPTION OF THE INVENTION (7) Technical Field The present invention relates to an amorphous alloy ribbon-wound magnetic core and a method for manufacturing the same.

More specifically, the present invention relates to a magnetic core used in a high-output magnetic switch used in a particle accelerator or the like, and which has a short switching time.

In particle accelerators, magnetic cores are required to generate pulses of high power, up to 1 aw or more, with short switching times and at high frequencies, up to 10 KHg or more.

Conventionally, high-pressure gas switches such as thyratrons have been used as pulse generators for particle accelerators, but the output and switching time are unsatisfactory.

On the other hand, a capacitor '1 as shown in FIG.
+'2 ......, On and saturable inductor L
1. The capacitance of each capacitor is equal to each other, and the inductance of each inductor is configured to be smaller than that of the higher-order stage, and by applying DC power to the input side, the capacitor 01 When the inductor L1 reaches saturation, its impedance decreases and the charge is transferred to the capacitor L1.
2, and by sequentially performing such charging and saturation up to n stages, the pulse width is sequentially compressed while preserving the energy of the original waveform, and the magnetic switch obtains a short pulse width and high output pulse. It is publicly known.

Inductor of each stage in such a magnetic switch
A magnetic core is used for Lj, L2...+"n,
The magnetic core is required to have the following characteristics.

First of all, it must have good saturability, so it must have good squareness and magnetic permeability μsa in the saturation region.
It is necessary that t be small. In this case, according to the study results of the present inventors, Br/B1 (1 (Br is the residual magnetic flux density, B10 is the magnetic flux density at 100e, see Figure 2) is 0.
It is preferable that it is 7 or more. Further, since μsat is proportional to the required volume of the magnetic core, the smaller μsat is, the more compact the magnetic core can be. The theoretical maximum compression coefficient of the pulse width is (magnetic permeability in the unsaturated region), μunsat and μs
The larger the difference from at, the fewer stages the LC circuit uses, and the smaller the magnetic switch becomes.

Second, since the inductor is excited from -Br to Ea (Be is the saturation magnetic flux density) of the B-H curve shown in FIG. 2, ΔBs=l-Brl+Be must be large.

Thirdly, since the magnetic core is excited with a current of about 10 KHz or higher, energy loss under high frequencies must be small.

Fourthly, it is necessary that the characteristics change little over time.

Next, problems associated with the fact that the magnetic switch core is a wound core will be explained.

In general, in wound cores for magnetic switches, the magnetic flux density changes over the course of 1H when a high-frequency current is applied to the magnetic core, and a large voltage proportional to this change is generated, so there is a risk of short circuits occurring between the wound layers. be. In order to prevent such short circuits, it is necessary to insulate the winding layers. Therefore, when implementing the method of insulating the winding layers, the first to fourth required characteristics must not deteriorate.

(4) Prior Art Ferrite is commonly used as a magnetic core material for magnetic switches, but ferrite is insufficient in the above-mentioned first to third magnetic properties, so it has the disadvantage of increasing the size of the magnetic core. be.

On the other hand, ribbons of amorphous magnetic alloys have also been put into practical use as magnetic core materials. In the case of silicon steel sheets, which are generally used as magnetic core materials, a glassy film is formed on the surface by one-sieve temperature annealing, and an insulating film is applied and baked.

However, since the temperature required to perform such interlayer insulation treatment is high, this technique cannot be applied to interlayer insulation of amorphous alloys. Therefore, in order to provide interlayer insulation between amorphous alloy ribbons, an insulating material such as MgO is coated, or a layer of an insulating material such as polyimide or polyethylene terephthalate is placed between the amorphous alloy ribbons. It is necessary to insert In the former method of applying an insulating material such as MgO, since both ends of the amorphous alloy ribbon are generally sharp, it is difficult to apply the insulating material well, which can lead to interlayer short circuits. It is not practical because it is easy to do.

Next, in order to obtain good magnetic properties as a characteristic of an amorphous alloy, it is necessary to heat treat the amorphous alloy at a temperature below the crystallization temperature and between about 300 and 500C. Note that, since polyimide and the like do not have sufficient heat resistance at the above-mentioned heat treatment temperature, heat treatment cannot be performed with a polyimide film or the like interposed between the amorphous alloy ribbons. Therefore, the amorphous alloy ribbons are heat treated and then a layer of insulating material is interposed between the ribbons.

The present inventor has investigated the magnetic properties of an amorphous alloy ribbon-wound core, particularly ΔB.
It has been found that in order to improve s=l-Brl+Be, it is necessary to heat-treat the amorphous alloy ribbon in a wound state, and it is also necessary to specify the state in which the insulating material layer is inserted.

(i) Purpose of the Invention The purpose of the present invention is to provide an amorphous alloy spring core with good magnetic properties and a method for manufacturing the same.

(1) Configuration of the Invention The amorphous alloy wound magnetic core according to the present invention is an amorphous alloy ribbon magnetic core, and the amorphous alloy ribbon is wound in the winding direction in a heat-treated state, The present invention is also characterized in that an insulating film for insulating the wound layers of the amorphous alloy ribbon is interposed between the wound layers.

The manufacturing method according to the present invention is a method for manufacturing an amorphous alloy ribbon-wound magnetic core, in which a first end of the amorphous alloy ribbon is placed inside a second end.
A first wound body is made by winding the ends with the ends facing outward, and then the first body is heat-treated, an insulating film is placed on the amorphous alloy thin body, and the first wound body is then heat-treated. 1 end is inner t1
1. The amorphous alloy ribbon and the insulating film are wound around a second winding body with the second end located on the outside, and the inner diameter of the second winding body is substantially equal to the inner diameter of the first winding body. I
+! There are 7 signs.

Hereinafter, the constituent elements of the present invention will be explained.

According to experiments conducted by the present inventor, when an amorphous alloy thin ribbon is heat-treated at a temperature below the crystallization temperature in the production of an amorphous alloy thin ribbon wound magnetic core (hereinafter simply referred to as a magnetic core), When the strip is heat treated in the expanded state, the magnetic core f4! ! It was found that the magnetic properties deteriorated by winding the heat-treated ribbon for the purpose of fabrication.

Therefore, the above heat treatment needs to be performed on the amorphous alloy f# band (the i@tI7) immediately after the winding is completed.

Figure 3 shows heat-treated polished amorphous alloy wound body 1 (first
(rolled body), its inner diameter is d, its outer diameter is smaller, and the inner first
End 1b, outer second end 1a shown. The heat treatment temperature is usually about 300 to about 5 ooc.

Specifically, the temperature and conditional force 1y are adjusted so that the best magnetic properties, especially ΔBB, can be obtained within the above range depending on the composition of the amorphous alloy.
ff, selected.

Such treatment is usually carried out at a temperature of, for example, 50e or more, especially 10e.
This is carried out by heating in a magnetic field of about 0.00° C. or more at a temperature of one Curie point or less for an appropriate period of time, and then cooling, for example air cooling. After heat treatment in a magnetic field, C↓ anisotropy is imparted in the longitudinal direction within the ribbon surface. The atmosphere for such heat treatment may be air, vacuum, inert gas, non-oxidizing gas, or the like. Amorphous alloy wound body 1 has a thickness of 20μ
m or less in thickness and generally 10 to 5001"11, especially 12
It is made by winding a long thin plate with a width of about 7 to 127 mm. In this case, if the thickness exceeds 20 μm, energy loss at high frequencies will increase and heat generation will increase. The thickness is particularly 5 to 118 μm, preferably 8
~15 μm.

As described above, in manufacturing a magnetic core, it is necessary to perform interlayer insulation, but heat treatment cannot be performed with an insulating film interposed between layers. FIG. 4 shows a magnetic core 10 (second wound body) with an insulating film 2 interposed between the layers of the amorphous alloy ribbon after heat treatment. Since the insulating film 2 is interposed between the layers, the outer diameter D2 of the magnetic core 10 is generally larger than the outer diameter D2 of the amorphous alloy wound body 1 (D2>DI). In the magnetic core (second wound body) according to the present invention, the first end 1b and the second end 1a are located inside and outside, respectively, as in the heat treatment, and the inside diameter d2 of the magnetic core 10 is amorphous. Almost equal to the inner diameter d1 of the alloy wound body 1 (first wound body) (,11+
d2) is necessary. If the relationship between the inner diameter d2 and dl is d2)dl or a2((al) and/or the first end 1b (second end 1a) is located outside (inside), ΔBB will be significantly greater than in the magnetic core of the present invention. Desirably, 2-al Δa = l l X 100 (%) is 0 to about +40%
, 1-20%. When Δd=0%, ΔBg is the highest. Hereinafter, winding the amorphous alloy ribbon in the same direction and in the opposite direction to the heat-treated winding direction will be referred to as forward winding and reverse winding, respectively.

Forward winding is an essential component of the magnetic core of the present invention. On the other hand, between the heat treatment process and the process of inserting the magnetic core insulating film between the layers, even if the process of winding in the opposite direction or flattening the amorphous alloy ribbon is performed, the magnetic core will not be aligned properly. If the amorphous alloy ribbon of the magnetic core is wound in the opposite direction, the magnetic properties of the amorphous alloy ribbon of the magnetic core will not be deteriorated by winding in the opposite direction or flat rolling.

Therefore, the magnetic properties of the amorphous alloy ribbon are not affected by the rolling (rolling) history between the heat treatment and the final winding process, and - the working cough ribbon remembers the forward winding with good magnetic properties. It has a kind of shape memory effect.

Next, a specific example of manufacturing the second wound body by the method of the present invention will be described in the fifth section.
This will be explained with reference to the figures.

In FIG. 5, 20 is an amorphous alloy ribbon obtained by winding the heat-treated winding band (first winding body) 1 (3rd FA) in the free direction, 21 is an insulating film, and these are the windings. It is unwoundly wound around the frames 22 and 23. 24 is an amorphous alloy ribbon 20 and an insulating film 2 preferably having a thickness of 0.1 to 25 μm.
1 indicates a magnetic core wound in alternating layers.

Note that when winding the magnetic core 2, it is necessary to apply appropriate tension to the amorphous alloy ribbon 20 and the insulating film 21. Appropriate tension strength is generally from several 1 to several tens of 1
It is.

In addition, since there is a gap between the ends of the amorphous alloy ribbon 20 that is only about the size of the insulating film 21, there is a possibility that discharge will occur, so in order to prevent discharge, the width of the insulating film 21 should be It must be larger than the width. The calculated width of the insulating film (on one side) is approximately several tens of micrometers, taking into consideration atmospheric discharge, induced voltage, magnetic core usage conditions (magnetic switch drive conditions), size of amorphous alloy ribbon, magnetic core size, etc. This is good, but in actual winding work, runout inevitably occurs, so the width of the insulating film 1 la (on one side) should be 2 mm or more.
Preferably, the thickness is between 2 and 5 nm.

In this case, an insulating material may be coated or adhered to the amorphous alloy ribbon after heat treatment, but the insulating performance will be inferior to that shown in FIG. 5.

End portion (second end) of amorphous alloy ribbon 20 and insulating film 21
The end portion of the magnetic core 24 is fixed to the outermost part of the magnetic core 24 by adhesive, welding, tape, etc., or by caulking with a caulking claw provided on the winding frame or the like.

Example: Amorphous alloy N with a thickness of 15 μn's and a width of 25.4 fnlR
band with one composition (Feo, 949Mno, osl)
7s (Sto, s9+ town, 275 oQ, os++ P
o, 045) 22 and the outer diameter (Dl - Fig. 3) 12
When the first wound body wound to have a diameter of 7 mm and an inner diameter (al) of 76 mm was heat treated in a magnetic field of 3000 C for 2 hours at 400 C, the obtained ΔB8 was 2.7 Teela. Next, when the first wound body was wound in the opposite direction with the inner diameter (dl), ΔBg=1.9 Te5la was obtained. In this case, a 2 μm thick polyethylene terephthalate film was inserted between the amorphous alloy ribbon layers.

Next, a second wound body was produced by winding the first wound body in the forward direction. In this case, a polyethylene terephthalate film with a thickness of 2 μm was inserted between the layers of the amorphous alloy ribbon, and the inner diameter (d2) and outer diameter (D2) of the second wound body were changed as shown in the following table. Each 8Be is shown in the table.

Table 1 From Table 1, if △d is not equally large, high △
It can be seen that Bs can be obtained.

(fJ+ Effects of the Invention According to the present invention, in manufacturing a magnetic core that involves heat treatment and winding, a magnetic core with a high ΔBa can be manufactured.

[Brief explanation of drawings]

Figure 1 is the equivalent circuit of the magnetic switch, Figure 2 is the Bnd13 wire of the magnetic core, Figure 3 is a conceptual diagram of the first winding body, Figure 4 is a conceptual diagram of the second winding body, and Figure 5 is a conceptual diagram of the second winding body. FIG. 3 is a diagram showing a method of winding the second winding body. 1...Amorphous alloy wound body (first wound body), 1a...
Second end, 1b... First end, 2... Insulating film, 10
...Magnetic core, 2G...Amorphous alloy ribbon, 21...Insulating film, 24...Magnetic core (second winding body), 26...Tension adjustment roll.

Claims (1)

[Claims] 1. An amorphous alloy ribbon-wound magnetic core, wherein the amorphous alloy ribbon is wound in the winding direction in a heat-treated state;
Further, an amorphous alloy ribbon-wound magnetic core characterized in that an insulating film for insulating between the wound layers of the amorphous alloy ribbon is interposed between the wound layers. 2. In the method for manufacturing an amorphous alloy ribbon-wound magnetic core, the first end of the amorphous alloy ribbon is wound inside and the second end is outside to form a first wound body, and then: heat-treating the first winding body, then disposing an insulating film on the amorphous alloy thin body, and forming a second winding body in which the first end is located on the inside and the second end is on the outside. An amorphous alloy characterized in that the amorphous alloy ribbon and the insulating film are wound around a rotating body, and the inner diameter of the second wound body is substantially the same as the inner diameter of the first rolled body. Method for manufacturing thin ribbon magnetic core.