JP2770037B2 - Core and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a core used for a saturable reactor used for a magnetic switch, a switching regulator, and the like, a cavity for a particle accelerator, and the like.

<Prior Art> Conventionally, an amorphous magnetic alloy having excellent magnetic, mechanical or chemical properties has been used as a core material. Amorphous magnetic alloys have magnetic properties such as high squareness ratio (Br / Bs) and high magnetic permeability (μ), and low coercive force (Hc), and are therefore saturable for magnetic switches and switching regulators. Suitable for core materials such as reactors and cavities for particle accelerators.

Among these, the saturable reactor is used, for example, in a strong pulse generation circuit for a magnetic switch. FIG. 1 shows an example of a circuit for generating a pulse using a multistage magnetic switch.

This circuit consists of an inductor L ₁ , a saturable reactor L ₂ and
And L _3, and is configured in three stages from the capacitor C _1, C ₂ and C ₃ Prefecture. The capacitance of each capacitor is equal, and the inductance of each saturable reactor
That is, it is set to be smaller on the output side.

In this configuration, when closing the switch S in the state in which C ₁ is charged, the charge of C ₁ flows through the inductor L ₁ to C _2. C ₂ is after charging, the saturable reactor L ₂ is saturated, the impedance decreases, the charge flows to the capacitor C _3. By sequentially performing such an operation up to the last stage, the current pulse width is sequentially compressed while maintaining the energy of the original waveform, and a pulse having a large current peak is obtained.

The core of such a saturable reactor for a magnetic switch needs to have a high squareness ratio and a high magnetic permeability, a small magnetic permeability at saturation (μ _sat. ), And a low coercive force.

In addition, conventionally, as a particle accelerator that accelerates charged particles such as various ions, electrons, and protons using an electric field or a magnetic field and gives high kinetic energy, it changes in addition to a DC accelerator such as a Cockcroft type, a Van de Graaff type, and the like. 2. Description of the Related Art Linear accelerators using an electric or magnetic field and rotary accelerators such as cyclotrons, synchrotrons, and betatrons are known.

Of these, the linear accelerator repeatedly accelerates charged particles with an alternating electric field many times to reach high energy, and generally generates a high-voltage alternating electric field of 20 to 100 MHz to accelerate particles passing through the center. Is what you do.

On the other hand, among these linear accelerators, a linear induction accelerator (induction linac) is known for accelerating a large current (Review of Scientific Instruments Vol. 35, p. 886)
1964 and others).

As shown in FIG. 2, a toroidal core made of a soft magnetic material is used as a one-turn electric field converter.
By supplying a pulse current i from the pulse generator,
It employs a method of generating an electric field E in the width direction of the toroidal core 1, and is regarded as a promising means for high-temperature plasma heating for nuclear fusion.

Such a toroidal cavity core 1 is also required to have a high squareness ratio and a high magnetic permeability and a low coercive force.

In addition to such a linear induction accelerator, in a rotary accelerator such as a synchrotron, when an alternating current is applied, for example, a core that generates an electric field or magnetic field for acceleration that changes at a constant frequency is used for an electric or magnetic field converter. In this case as well, the core is required to have a high squareness ratio and a high magnetic permeability and a low coercive force, as described above.

Also, in various particle beam controllers, a core for converting a pulse current for excitation or the like into a pulsed or alternating electric field or magnetic field and using the electric field or magnetic field to variously control the particle beam flux is used. In such a case, it is required that the squareness ratio and the magnetic permeability are high and the coercive force is low.

Further, the same applies to a switching regulator, an excimer laser cavity core, and the like.

For such a magnetic switch or the like, a toroidal core is used in which an amorphous magnetic alloy thin plate is wound through an insulating film to increase the withstand voltage and insulation.

By the way, the amorphous magnetic alloy thin plate is usually heat-treated at a temperature of about 350 to 500 ° C. in order to reduce the internal stress and improve the magnetic properties.

A heat treatment technique for winding through an insulating film is described in, for example, JP-A-60-30103.

In the core described in JP-A-60-30103,
A method that does not perform simultaneous heat treatment is used. First, only an Fe-based amorphous magnetic alloy thin plate is wound and heat treated. Therefore, polyester or the like having low heat resistance can be used for the insulating film. Then, after the amorphous magnetic alloy thin plate is once rewound, it is again wound through an insulating film to obtain a core in the same winding state as the thin plate during the heat treatment.

<Problems to be Solved by the Invention> However, in the core described in JP-A-60-30103, first, only an amorphous magnetic alloy thin plate is wound and heat-treated. Next, after the film is once rewound, the amorphous magnetic alloy thin plate is wrapped to the original state via an insulating film. Therefore, the winding of the amorphous magnetic alloy sheet is repeated three times, and the final winding state becomes thicker by the insulating film, so that the curvature of the thin sheet gradually changes, and the winding state at the time of heat treatment is greatly changed. I will. For this reason, internal stress and magnetostriction increase, and as a result, there are disadvantages such as a decrease in the squareness ratio and an increase in the magnetic permeability at the time of saturation. Furthermore, since the heat treatment is performed at a high temperature and the winding is repeated three times, the manufacturing time is increased and the winding cost is increased.

An object of the present invention is to perform a heat treatment on an amorphous magnetic alloy thin plate via a low heat-resistant insulating film,
A low cost core having a short production time and easy production, a core having a high squareness ratio and a high magnetic permeability, a low magnetic permeability at the time of saturation, a low magnetic coercive force, and the like, and a method for producing the core. Is to provide.

<Means for Solving the Problems> Such an object is achieved by the present invention of the following (1) and (2).

_{(1) Co 100- (x +} y + z) Fe x Mn y (B 1-p Si p) z ( however, 2 ≦ x ≦ 8,0 ≦ y ≦ 10,16 ≦ z ≦ 24,0.01
≦ p ≦ 0.5. A core characterized in that a thin plate of an amorphous magnetic alloy having an atomic ratio composition of (1) is wound through an insulating film having a heat deformation temperature of 200 ° C. or lower, and heat-treated in the wound state.

_{(2) Co 100- (x +} y + z) Fe x Mn y (B 1-p Si p) z ( however, 2 ≦ x ≦ 8,0 ≦ y ≦ 10,16 ≦ z ≦ 24,0.01
≦ p ≦ 0.5. A method for producing a core, comprising: winding a thin plate of an amorphous magnetic alloy having an atomic ratio composition of (1) through an insulating film, and then performing a heat treatment at a temperature of 150 to 350 ° C.

<Function> In the present invention, the amorphous magnetic alloy which has been conventionally heat-treated at a relatively high temperature of 350 ° C. to 500 ° C. has a temperature of 150 ° C.
An amorphous magnetic alloy composition capable of obtaining sufficient magnetic properties even with a heat treatment at a relatively low temperature of 350 ° C. has been found. Therefore, even if heat treatment is performed with an insulating film having low heat resistance interposed therebetween, sufficient pressure resistance and insulation properties can be obtained, and the number of times of winding may be one. Therefore, the internal stress applied to the core can be reduced.

Therefore, the core of the present invention has good magnetic properties such as a high squareness ratio and a high magnetic permeability, a low magnetic permeability at the time of saturation, a small coercive force, a short production time, low cost, and easy production. It is.

Amorphous magnetic alloy sheet for use in the present invention <Concrete Configuration of the Invention> In atomic ratio, represented by the formula _{Co 100- (x + y + z} ) Fe x Mn y (B 1-p Si p) z composition With heat treatment of 15
This is an amorphous magnetic alloy composition that can obtain necessary and sufficient magnetic properties by performing at a temperature of 0 to 350 ° C.

In the above formula, the content of each element is 2 ≦ x ≦ 8, preferably 3 ≦ x ≦ 7, 0 ≦ y ≦ 10, preferably 0 ≦ y ≦ 3,
16 ≦ z ≦ 24, 0.01 ≦ p ≦ 0.5, preferably 0.05 ≦ p ≦ 0.2
And

When the heat treatment is performed at a temperature of 150 to 350 ° C. outside the above range, it is difficult to obtain an amorphous magnetic alloy sheet having good magnetic properties such as a squareness ratio.

In addition, in addition to the above composition, the amorphous magnetic alloy thin plate has Ti,
One or more elements selected from Zr, V, Nb, Ta, Cr, Mo, W, Ni and Cu may be contained in an amount of 3 at% or less.

The thickness of the amorphous magnetic alloy thin plate is about 10 to 30 μm.

If the thickness is less than the above range, manufacturing becomes difficult. If the thickness exceeds the above range, the magnetic properties cannot be satisfied.

The production of the amorphous magnetic alloy thin plate is performed by a usual method.

For example, it is manufactured by dissolving each element to form a molten alloy having a predetermined composition, rapidly cooling the liquid phase at a cooling rate of 10 ⁵ ° C / sec to 10 ⁶ ° C / sec or more, and solidifying.

To quench the molten alloy, the molten alloy is sprayed from a nozzle, and a known method such as a twin roll method, a single roll method, or a centrifugal quenching method is used.

In the present invention, as the insulating film that can be heat-treated at a low temperature, various ones can be selected from a wide range of insulating resins.

However, it is preferable to use polyester, polyamide, or the like because the cost can be significantly reduced. Polyethylene terephthalate (PET) is particularly suitable as the polyester. The insulating film may have a heat deformation temperature of 200 ° C. or less, preferably about 80 to 200 ° C.

The thickness of the insulating film is about 1 to 10 μm, preferably about 2 to 6 μm.

If it is less than the above range, it becomes difficult to wind the core, and if it exceeds the above range, the space factor of the magnetic component of the core decreases, and sufficient magnetic properties cannot be obtained.

In the present invention, first, an amorphous magnetic alloy thin plate having a predetermined composition is wound through the insulating film to produce a toroidal core.

The size of the core is appropriately determined according to the application, and the winding is performed by using a winding frame, a winding core, or the like as necessary, and the ends are fixed.

In this case, the manufacture and size of the bobbin, the core, and the like can be various depending on the application.

In addition, glass, resin, metal, or the like can be used as the material. For fixing the end, various methods generally used such as a method of bonding, welding, attaching with a tape or the like, and a method of caulking can be used.

After winding, heat treatment is performed to alleviate internal stress, reduce magnetostriction, and improve magnetic properties such as squareness ratio.

The heat treatment may be performed in a non-magnetic field or in a magnetic field, but is preferably performed in a magnetic field to improve the squareness ratio.

The heat treatment is performed at a temperature lower than the crystallization temperature Tx, and is performed at 150 to 350 ° C, preferably 200 to 300 ° C for the above composition.

Within the above range, even if heat is applied to the insulating film having low heat resistance, the insulating film is not affected, the withstand voltage is large, and a sufficient insulating effect can be exhibited.

In general, it is considered that heat is hardly affected even if heat is applied to the insulating film up to about 100 ° C. higher than its thermal deformation temperature.

As the heat treatment atmosphere, a non-oxidizing, oxidizing, or reducing atmosphere can be used, and a non-oxidizing atmosphere is preferably used.

The withstand voltage of the core completed in this manner is about 10 to 100 V / sheet between amorphous magnetic alloy sheets.

A predetermined number of windings are wound around the completed core according to the purpose to form a saturable reactor or the like. A conventional known method may be used to wind the winding.

The core of the present invention can be suitably used for a saturable reactor such as a magnetic switch and a switching regulator, a cavity for a particle accelerator, and the like.

<Example> Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.

Example 1 Various amorphous magnetic alloy thin plates having a composition shown in Table 1 and having a thickness of 22 μm for the present invention and for comparison were produced by a normal single roll method.

As the insulating film, a 6 μm-thick polyamide film with low heat resistance (Aramid manufactured by Toray having a heat distortion temperature of 180 ° C.) was used. And a toroidal shape with a height of 25 mm.

Next, while applying a magnetic field of 200e to these, Table 1
Was performed in a magnetic field for 60 minutes at the heat treatment temperature shown in Table 1. Note that only core sample No. 7 is PET with a heat distortion temperature of 120 ° C.
And heat treatment in a magnetic field was performed for 180 minutes.

 The heat treatment in a magnetic field was performed in a nitrogen gas atmosphere.

Thus, core samples No. 1, No. 3, and No. 7 were produced. Note that such a manufacturing method is referred to as A.

In addition, as a comparative core sample, a core sample No. 5 was prepared in the same manner except that the insulating film was changed to a polyimide film having a thickness of 7.5 μm (Kapton manufactured by DuPont having a heat distortion temperature of 230 ° C.).

Further, only an amorphous magnetic alloy thin plate was wound without using an insulating film, and a core sample No. 6 for comparison was prepared in the same manner as in the other cases. Note that such a manufacturing method is referred to as C.

Further, a core sample for comparison was prepared by a known core manufacturing method described in JP-A-60-30103. In this case, first, only the amorphous magnetic alloy thin plate was wound.

The heat treatment was performed under the same conditions as in the example except that the heat treatment temperature was set to the temperature shown in Table 1. After the amorphous magnetic alloy thin plate was rewound once, it was rewound again via an insulating film to obtain core samples No. 2 and No. 4. In this case, 6 μm thick PET (heat deformation temperature: 120 ° C.) was used for the insulating film, and the size of the core after winding was the same as that of the example.
Note that such a manufacturing method is referred to as B.

For each core sample, withstand voltage, squareness ratio at DC (DC) (Br / Bs), permeability at saturation (magnetic field 1000e) (μ _sat. )
Was measured.

 Table 1 shows the results.

In the withstand voltage measurement, a voltage of 50 V / a voltage between the thin plates was applied between the amorphous magnetic alloy thin plates, and the results were indicated by ○.

The effect of the present invention is clear from the results in Table 1.

In addition, polyimide (Kapton manufactured by DuPont) has excellent heat resistance, but the film thickness is 7.5 μm at the thinnest.
m or more, and there is no 2 μm to 6 μm film suitable for this application. For this reason, when the amorphous magnetic alloy thin plate and the film are simultaneously wound, the space factor of the crystalline magnetic alloy thin plate in the core decreases. Further, the polyimide film has a drawback that the surface accuracy is poor and the space factor of the core is low when the amorphous magnetic alloy thin plate and the film are simultaneously wound to form a core.

The above is as shown by the core sample No. 5 in Table 1. Therefore, the core of No. 5 has a magnetic flux variation width (Δ
B) and the saturation magnetic flux density (B _ms ) have decreased.

<Effect of the Invention> In the present invention, an amorphous magnetic alloy that can be heat-treated at a low temperature with respect to the heat-resistant temperature of the insulating film was found. Necessary and sufficient core characteristics for a magnetic switch or the like can be obtained in a state where the film is not deformed or brittle even if heat treatment is performed in the wound state.
For this reason, the core of the present invention has a sufficient withstand voltage and good insulation. In addition, since simultaneous heat treatment can be performed, the number of turns of the amorphous magnetic alloy thin plate may be one, and the cost can be significantly reduced. Also, since the internal stress can be reduced,
Core characteristics can be improved.

Therefore, the core of the present invention has good magnetic properties such as a high squareness ratio and a high magnetic permeability, a small magnetic permeability at the time of saturation, and a small coercive force. Therefore, when the present invention is used for a magnetic switch, a switching regulator, a particle adder, and the like, very good characteristics can be obtained.

Further, according to the present invention, the manufacturing time is short, the manufacturing is easy, and the manufacturing cost is low, so that the mass production corresponding to the demand becomes easy.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a pulse generation circuit having saturable reactors L ₂ and L ₃ for a magnetic switch. FIG. 2 is a circuit diagram of a cavity for accelerating or controlling charged particles using an amorphous magnetic alloy core. Explanation of symbols 1 ... core

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01F 1/153

Claims (2)

(57) [Claims] 1. A _{Co 100- (x + y + z} ) Fe x Mn y (B 1-p Si p) z ( however, 2 ≦ x ≦ 8,0 ≦ y ≦ 10,16 ≦ z ≦ 24,0.01
≦ p ≦ 0.5. A core characterized in that a thin plate of an amorphous magnetic alloy having an atomic ratio composition of (1) is wound through an insulating film having a heat deformation temperature of 200 ° C. or lower, and heat-treated in the wound state. 2. A _{Co 100- (x + y + z} ) Fe x Mn y (B 1-p Si p) z ( however, 2 ≦ x ≦ 8,0 ≦ y ≦ 10,16 ≦ z ≦ 24,0.01
≦ p ≦ 0.5. A method for producing a core, comprising: winding a thin plate of an amorphous magnetic alloy having an atomic ratio composition of (1) through an insulating film, and then performing a heat treatment at a temperature of 150 to 350 ° C.