JPH0351081B2 - - Google Patents

Description

BACKGROUND OF THE INVENTION Technical Field The present invention relates to a magnetic core for a noise filter. More specifically, the present invention relates to magnetic cores of various coils used as noise filters for removing pulsed noise. Prior art and its problems For example, when pile noise is input to equipment from a power line or power supply circuit, pile noise may accidentally enter the equipment or leak from the equipment to the outside. For this reason, a power line noise filter is inserted into the power line or power circuit to prevent this. As noise filters for power supply lines, etc., it is often advantageous to use a coil as a filter functional element due to its robustness. Coils or common mode or differential mode LC noise filters are often used to remove pulse-like noise. Conventionally, ferrite, powder material, etc. have been used as materials for forming the magnetic cores of various coils in noise filters for power supply lines and the like. However, the ferrite magnetic core has a saturation magnetic flux density (Bs)
For example, if the coil is used as a common mode choke coil to form a common mode noise filter and inserted into a 100V AC power line, the magnetic core will become saturated when large voltage noise is input, making it difficult to use it effectively. This can lead to equipment malfunctions. In addition, powder magnetic cores have a high saturation magnetic flux density, but have low magnetic permeability and low inductance with respect to input voltage, and in order to obtain the necessary characteristics, it is necessary to use a large core, which is a major drawback in practical use. ing. Under these circumstances, the applicant of this application
Previously, it was proposed to use a closed magnetic circuit core made of a substantially completely amorphous magnetic alloy as the magnetic core of the coil of a noise filter for power supply lines. The magnetic core according to the above proposal has a significantly improved ability to stop high-voltage noise current pulses compared to conventional magnetic cores. However, noise current pulses that are superimposed on this power line or power supply circuit often
It is generated as an extremely large pulse-like voltage of 1000V or more and 1μsec or more. It has also been found that the above-mentioned substantially completely amorphous closed magnetic circuit core cannot withstand practical use against such large voltage pulse-like noise. Therefore, the inventor conducted further research and first
It has been proposed that the ability to remove large voltage pulse noise can be improved by partially introducing crystalline material into an amorphous magnetic alloy. However, it is desired that noise filters with a magnetic core formed from thin strips of amorphous magnetic alloy that partially contains crystals be further improved in their ability to remove pulse-like large voltage noise. Furthermore, reliability such as corrosion resistance, durability, impact resistance, and high voltage pulse resistance is still insufficient. Purpose of the Invention The invention of this application was made in view of the above-mentioned circumstances, and its main purpose is to eliminate pulse-like noise, especially of high voltage, which is accidentally superimposed on direct current or alternating current. A noise filter with an improved magnetic core made of an amorphous magnetic alloy for noise filters, which has excellent noise removal ability and is also highly reliable in terms of corrosion resistance, durability, impact resistance, high voltage pulse resistance, etc. The objective is to provide a magnetic core. The present inventor has conducted extensive research for such purposes and has come up with the invention of this application. That is, the first invention of this application partially contains crystalline material, and the crystalline/amorphous ratio is 0.1 to 50%.
This is a magnetic core for a noise filter, characterized in that it is formed from a wound body formed by winding a ribbon of an amorphous magnetic alloy having a composition represented by the following formula [1]. Formula [] M _x Mn _y (Si _p B _q C _r ) _z [In the above formula, M is 10at% with respect to Fe or Fe and Fe
1 of the following transition metal elements other than Fe and Mn
Represents a combination with more than one species, x+y+z=100at
%, of which y is 0.1 to 10at% and z is 16
~32at%. Furthermore, p+q+r=100%, of which p is 20 to 80% and r/q is 0.01 to 0.4. In addition, (1/5)p+6≦z≦−(1/2)p+67. The second invention also provides a ribbon of an amorphous magnetic alloy that partially contains crystalline material, has a crystalline/amorphous ratio of 0.1 to 50%, and has a composition represented by the following formula []. This is a magnetic core for a noise filter, characterized in that it is formed from a wound body. Formula [] M _x Mn _y (Si _p B _q C _r P _s ) _z [In the above formula, M is 10at% with respect to Fe or Fe and Fe
1 of the following transition metal elements other than Fe and Mn
Represents a combination with more than one species, x+y+z=100at
%, of which y is 0.1 to 10at% and z is 16
~32at%. Furthermore, p+q+r+s=100%, of which p is 20 to 80%, s is 5% or less, and r/q is
It is 0.01-0.4. In addition, (1/5)p+6≦z≦−(1/2)p+67. Specific Structure of the Invention Hereinafter, the specific structure of the invention of this application will be explained in detail. The amorphous magnetic alloy ribbons of the first and second inventions of this application have the above formulas [] and [], respectively.
It has the composition shown in . In the above formulas [] and [], M is Fe
or Fe and other transition metal elements (Sc~Zn, Y
Cd, La~Hg, Ac~), but preferred specific examples of elements contained in combination with Fe include Co, Ni, Cr, Cu, Mo, Nb, Ti, W, V,
One or more of Zr, Ta, Y, and rare earth elements can be mentioned. In this case, other elements should be less than 10at% with respect to Fe.
Generally, it can be contained in a range of 0.1 to 5 at%. On the other hand, Mn, which is contained as an essential component in the ribbon,
The content y is 0.1 to 10 at%. If it is less than 0.1%, the change in inductance over time is large. Furthermore, the temperature and time required for heat treatment for precipitation of microcrystals, which will be described later, are severely restricted, making it difficult to contain crystalline materials as desired. When y exceeds 10at%, it becomes difficult to make a thin ribbon. Moreover, the saturation magnetization decreases, and the ability to remove large voltage noise decreases. On the other hand, y is 0.1 to 10 at%, preferably 0.1
At ~5at%, such inconvenience disappears. On the other hand, the element abundance z of Si, B and C, or the vitrification elements consisting of Si, B, P and C, is 16 to
It is 32at%. When z is less than 16at%, it becomes difficult to make a thin ribbon. Moreover, the crystallization temperature also becomes low, making heat treatment difficult. When z exceeds 32at%, it becomes difficult to make a thin ribbon. In addition, saturation magnetization decreases, causing problems in magnetic properties, and furthermore, heat treatment becomes difficult. On the other hand, when z is 16 to 32%, such defects become extremely small. Furthermore, the Si content ratio p in the vitrification element is 20~
It is 80%. When p is less than 20%, the inductance changes greatly over time, making it impossible to obtain a stable magnetic core. When p exceeds 80%, it becomes difficult to form thin ribbons.
Furthermore, heat treatment becomes difficult. On the other hand, when p is 20 to 80%, such drawbacks are eliminated. Moreover, between the total content of vitrifying elements (Si+B+C or Si+B+C+P) z at% and the Si content ratio p%, (1/5)p+6≦z≦−(1/5)
2) The relationship P+67 must exist. This is z>-(1/2)p+67, or z<
This is because if the temperature is (1/5)p+6, it becomes difficult to make a thin ribbon and heat treatment becomes difficult. In addition, the total content of vitrification elements z (at%)
As mentioned above, there is a difference between and the Si content ratio p (%),
16≦z≦32, 20≦p≦80, and (1/5)p+6≦
There is a relationship: z≦−(1/2)p+67. If we explain these relationships according to Figure 1,
Taking z (at%) on the vertical axis and p (%) on the horizontal axis, (p,
z), A(20, 32), B(70,
32), C (80, 27), D (80, 22), E (50, 16), F
(20, 16) and A are sequentially connected by straight lines, and the area on these straight lines and the area surrounded by these straight lines is the condition for z and p to be satisfied in both inventions of this application. In addition, the carbon C content ratio r in the vitrification element is
The value r/q divided by the B content ratio q is 0.01 to 0.4. If it is less than 0.01, the desired effects of the invention of this application cannot be obtained. If it exceeds 0.4, it becomes difficult to form a thin ribbon and problems occur in magnetic properties. On the other hand, in the first invention of this application, the vitrification element consists of Si, B and C, but in the second invention, P is contained in addition to Si, B and C. By including P in the vitrification element, changes in inductance over time are suppressed and durability is improved. In this case, in the above formula [], the P content s
is 5% or less. This is because when s exceeds 5%, the ability to remove large voltage noise decreases. Note that if s is less than 0.01%, the effect of improving durability by adding P is not significant, so the P content s
is 0.01 to 5%, more preferably 0.01 to 2%. Furthermore, if necessary, such vitrification elements may further contain one or more of Al, Be, Ge, Sb, In, etc. within a range of 10% or less of the total amount of vitrification elements. The effect of the invention of the application shall not be diminished. No. 1 of this application having the composition as detailed above.
The ribbon of amorphous magnetic alloy in the second invention partially contains crystalline material. In the ribbon, the crystalline material partially contained in the amorphous material is generally precipitated microcrystals and mixed in the amorphous material. Therefore, when a ribbon is subjected to X-ray diffraction, the diffraction spectrum shows a pattern in which a peak indicating the presence of crystalline material is superimposed on a halo characteristic of amorphous material. In addition, spots are superimposed on the halo in the diffraction image,
A Debye-Schierer ring with a predetermined ring diameter and ring width appears. Then, by taking the area ratio between the halo and the peak of the diffraction spectrum, the abundance ratio of crystalline and amorphous in the ribbon can be determined. The ratio is 0.1-50%. Further, the precipitated microcrystals are generally considered to have an average grain size of about 10 to 1000 Å, based on the ring diameter and ring width of the Debye-Schierer ring. In the ribbon having the composition as described above,
By partially including microcrystals in this manner, when a magnetic core for a noise filter is formed from a thin ribbon, the ability to remove large voltage pulse noise is significantly improved, and the thermal stability is also improved. As long as the ribbons in the first and second inventions of this application satisfy the conditions detailed above, there are no particular limitations on other conditions. However, as a result of partially introducing crystalline material into the ribbon, magnetic anisotropy is imparted in a predetermined direction within the ribbon surface, which improves magnetic permeability and further improves noise removal ability. This is preferable because it also facilitates adjustment of various magnetic properties. In this case, it is preferable that the magnetic anisotropy be introduced in one predetermined direction within the plane of the ribbon, usually as uniaxial anisotropy. That is, microcrystals are precipitated by heat-treating a thin ribbon of an almost completely amorphous magnetic alloy in a non-magnetic field before or in some cases after winding as described below. When this is done, uniaxial anisotropy is usually imparted to the ribbon in the longitudinal direction, and the magnetic permeability is improved at this time. In addition, if microcrystals are precipitated by heat treatment by applying a magnetic field before or after winding the ribbon in a direction that makes a predetermined angle with the longitudinal direction of the ribbon, Uniaxial anisotropy is imparted in the direction forming the , and at that time, by setting the anisotropy direction to a predetermined direction, the squareness ratio and the unsaturated region of the B-H loop can be adjusted as desired, Moreover, the ability to remove large voltage noise can be further improved. The existence of such magnetic anisotropy is explained by the conventional method,
This can be easily verified by measuring the torque curve. The thin strips as detailed above are generally 10~
It is a long thin plate with a thickness of about 100 μm and a width of about 0.1 to 50 cm. The magnetic core for a noise filter in the first and second inventions of this application is composed of a wound body formed by winding such a thin ribbon. That is, the magnetic core may be formed from the winding itself of the ribbon. Alternatively, cut the rolled body to create a U-shape, C-shape, I-shape.
It is also possible to make a cut piece into a shape such as a letter or an L-shape, use this cut piece as a cut core, and make a magnetic core by abutting the cut cores against each other. Furthermore, the cut pieces are connected to form a predetermined shape, for example, E.
A magnetic core may be formed by forming a cut core in a shape such as a letter, and by abutting these cut cores against each other, or by abutting this cut core against a cut core made of a cut body such as the above-mentioned I shape. In this way, when the magnetic core is formed into a cut core shape, the winding operation becomes easy. As described above, the magnetic core of the invention of this application is composed of a wound body of thin ribbons, and is not formed by laminating thin ribbons into a predetermined shape. This is due to the following reasons. That is, as described above, preferable results are obtained when the ribbon is given uniaxial magnetic anisotropy in a predetermined direction within the ribbon surface by precipitation of microcrystals. Such treatment for precipitation of microcrystals is usually performed before forming the wound body, but at this time, the direction of the easy axis in the wound body is constant with respect to the magnetic path direction. , high characteristics such as noise removal ability can be obtained. On the other hand, when creating a laminated structure, the directions of the magnetic path and easy axis are not constant because thin strips with a certain in-plane anisotropy are, for example, photoetched or punched and then laminated. Therefore, high characteristics such as noise removal ability cannot be obtained. Furthermore, when processing for microcrystal precipitation after winding, it is possible to easily introduce an easy axis having a desired constant angle to the magnetic path when forming a wound body. can. On the other hand, in the laminated type, the angle between the two is set at a constant angle in the magnetic path.
It is not possible to set it to an arbitrary value, and even if it were possible, it would be very difficult to control. The magnetic core of the invention of this application can be easily manufactured not only when it is made of a wound body itself, but also when it is made into various cut core shapes as mentioned above, and even when gaps are provided as necessary in the magnetic path. The angle that the axis makes with the magnetic path direction is always constant and can be any angle. Note that the wound type is also better in terms of characteristic deterioration during core processing. As a result of the magnetic core of the invention of this application being composed of the wound body in this way, it is easy to manufacture.
Manufacturing costs are low. When constructing a magnetic core from a wound body in this way, the wound body is usually formed by winding a ribbon around a predetermined winding frame, winding core, etc., and fixing the ends thereof. In this case, the structure, shape, etc. of the winding frame, winding core, etc. can be varied. The material may be metal in addition to porcelain, glass, resin, etc., and may also be a magnetic material such as silicon steel plate or permalloy. In addition, the fixing of the ribbon end is
By adhesive, welding, tape, etc., or
It may also be caulked using a caulking claw provided on the winding frame or the like. Note that an insulating material may be interposed between the wound ribbons. Further, the winding shape of the thin ribbon may be a circular ring shape or a rectangular ring shape or the like. The magnetic core of the invention of this application is usually produced as follows. First, a nearly completely amorphous ribbon is obtained from a master alloy having a corresponding composition according to a known high-speed quenching method. This ribbon is then usually subjected to a treatment for precipitation of microcrystals. Such treatment is usually carried out in the absence of a magnetic field by heating at a temperature near the crystallization temperature for a suitable period of time, followed by cooling, for example air cooling. The heating temperature, heating time, cooling rate, etc. can be easily determined experimentally depending on the required characteristic values. The atmosphere for such heat treatment may be air, vacuum, inert gas, non-oxidizing gas, or the like. Alternatively, in addition to this, the above heat treatment can also be performed in a static magnetic field. In this case, the applied magnetic field is, for example, about 100 Oe. At this time, anisotropy forming a predetermined angle with the longitudinal direction within the ribbon surface is imparted. Further, the heat treatment can be performed while applying tension, or even in a rotating magnetic field depending on the case. Next, as described above, this ribbon is wound to obtain a wound body, which can be used as a magnetic core as it is, or various cut cores can be formed from this to form a magnetic core, and air gaps can be created in the magnetic path as necessary. Or,
A magnetic core for a noise filter according to the invention of this application is formed. It should be noted that the ribbon may not be subjected to the treatment for precipitating microcrystals in advance, but the treatment may be performed either after the production of the wound body, after the formation of the cut core, or after the formation of the voids. Further, when the ribbon is previously subjected to a treatment for precipitation of microcrystals and then a wound body is obtained, heat treatment may be separately performed for strain removal after the winding body is produced. Specific operation of the invention In this way, the magnetic core of the invention of this application having the composition shown by the above formula [] or [] is created, but such a magnetic core is not wound with a winding. , and other predetermined processes are applied to make various coils used in noise filters. Such a coil is extremely useful for noise removal, such as as a noise filter coil inserted into a power line or the like, or as a coil used in a differential mode or common mode LC noise filter. In such a case, the magnetic core can be wound with a wire to form a chiyoke coil used as a noise filter, which can be inserted into a power supply line to effectively remove pulse-like noise at a voltage as high as 1000V. Further, as shown in FIG. 2, two windings 31 and 32 may be wound around the magnetic core 1 to form a common mode choke coil 40. In this case, the winding directions of the windings 31 and 32 are determined so that the magnetic flux due to the reciprocating current cancels each other out. For example, a circuit as shown in FIG. A noise filter is formed. In this case, in FIG. 2, a capacitor C ₁ is placed at one end between the pair of windings 31 and 32 of the common mode choke coil 40, and capacitors C ₂ , C ₃ , C ₄ and a resistor are placed at the other end. R ₁ and R ₂ are connected,
The connection point of capacitors C ₃ and C ₄ and resistors R ₁ and R ₂ is grounded. When such a common mode noise filter is inserted into a power supply line, even if pulsed noise with a voltage as high as 1000V is input, the noise output voltage shows an extremely small value, and it exhibits an extremely effective noise filter function. Specific Effects of the Invention The noise filter magnetic cores of the first and second inventions of this application have extremely high noise removal ability as a noise filter. Moreover, it does not have any drawbacks such as deterioration of characteristics such as noise removal ability over time, and has extremely high reliability in terms of corrosion resistance, durability, impact resistance, high voltage pulse resistance, etc. Furthermore, the heat treatment temperature range is wide and manufacturing is easy. The magnetic core of the second invention exhibits even better corrosion resistance and durability. Specific Examples of the Invention Next, examples of the invention of this application will be shown and the invention of this application will be explained in further detail. Example 1 Composition included in the above formula []
Fe ₇₅ Mn ₁ Si _14.4 B _9.4 C _0.2 (z=24at%, p=60%,
An amorphous magnetic alloy ribbon No. 1 having an amorphous magnetic alloy ribbon No. 1 having an anomalous ratio of 0.02) was obtained by a high-speed quenching method. The ribbon is almost completely amorphous and has a thickness of 30 μm and a width of 8 mm. Next, this thin strip No. 1 was divided into 5 parts, one of which was not subjected to any treatment, and the other 4 parts were divided into 5 parts.
First, heat treatment was performed in a non-magnetic field at the temperature and time shown in Table 1 below to obtain samples Nos. 1-1 to 1-6.

[Table] When X-ray diffraction was performed on these samples Nos. 1-1 to 1-6, the results shown in Table 1 above were obtained. In addition, the crystalline/
The amorphous ratio was 0.1 to 50%, and the crystalline/amorphous ratio of sample Nos. 1-6 was over 50%. Separately, the ribbon 1 was divided into five parts and wound into a toroidal shape having an inner diameter of 19 mm, an outer diameter of 31 mm, and a width of 8 mm to obtain a total of five wound bodies. A total of five wound bodies 1-1 to 1 obtained in this way
-6, after performing the five types of heat treatment shown in Table 1 above, the rolled body is impregnated with an epoxy resin,
The resin was cured to obtain magnetic cores Nos. 1-1 to 1-6. Next, the magnetic cores 1-1 to 1- obtained in this way
8, two windings 31 and 32 with a predetermined number of turns were wound so that the magnetic flux due to the reciprocating current was canceled out to create a common mode York coil. Then, using the common mode choke coil created in this way, capacitors C ₁ , C ₂ , C ₃ ,
Using _C4 , we created a common mode noise filter as shown in Figure 2. In this case, between one end of the windings 31 and 32
A 0.22μF capacitor C ₁ is connected to the other end, and a 0.22μF capacitor C ₂ and 5000pF each are connected to the other end.
C ₃ and C ₄ are connected. Using such a common mode noise filter, as shown in Figure 2, one end of capacitor _C1 is grounded through a 50Ω resistor _R3 , and the other end is connected to a pulse generator through attenuator A.
PG and further connect 50Ω resistors R _{1 and} R ₂ in parallel with capacitors C ₃ and C ₄ , respectively, and resistors R ₁ ,
The connection point of R ₂ was grounded and one end of resistor R ₁ was connected to the oscilloscope. Using such a measurement circuit, magnetic cores 1-1 to 1-
A pulse of 1000 V and 1 μsec was input to the common mode noise filter configured for each of the above-mentioned common mode noise filters using a pulse generator PG via an attenuator A, and the output voltage at that time was measured. Table 2 shows the results.
Shown below.

[Table] Furthermore, after leaving each of these magnetic cores at 120℃ for 1000 hours, we performed the same measurements as above and conducted a durability test, and Nos. 1-3 to 1-6 had almost no characteristics. While there was no change, No. 1-1, 1-
2, the characteristics deteriorated by 10 to 20%. From these results, the effects of the invention of this application are clear. Note that, as shown in FIG. 3, unlike the case shown in FIG. 2, when a measuring circuit in which both ends of the capacitor _C1 were connected was used, results exactly similar to those described above were obtained. Example 2 Various amorphous magnetic alloy ribbons having compositions z and p as shown in Table 3 below were prepared, and a wound body having the same size as in Example 1 was obtained. minutes,
Heat treatment was performed in the absence of a magnetic field. A halo and a peak were present in the X-ray diffraction spectrum of each ribbon. Next, it was impregnated with an epoxy resin and fixed to obtain each magnetic core No. 3 to 14. In addition, in No. 11, it was not possible to obtain a good ribbon. For each of these magnetic cores, the output voltage for 1000 V and 1 μsec was measured under the same conditions as in Example 1, and the results shown in Table 3 were obtained.

【table】

[Table] 〓Comparison
13

Claims (1)

[Claims] 1. A ribbon of an amorphous magnetic alloy that partially contains crystals, has a crystalline/amorphous ratio of 0.1 to 50%, and has a composition represented by the following formula [ ]. A magnetic core for a noise filter, characterized in that it is formed from a wound body. Formula [] M _x Mn _y (Si _p B _q C _r ) _z [In the above formula, M is 10at% with respect to Fe or Fe and Fe
1 of the following transition metal elements other than Fe and Mn
Represents a combination with more than one species, x+y+z=100at
%, of which y is 0.1 to 10at% and z is 16
~32at%. Furthermore, p+q+r=100%, of which p is 20 to 80% and r/q is 0.01 to 0.4. In addition, (1/5)p+6≦z≦−(1/2)p+67. ] 2 A winding formed by winding a ribbon of an amorphous magnetic alloy that partially contains crystals, has a crystalline/amorphous ratio of 0.1 to 50%, and has a composition represented by the following formula [] A magnetic core for a noise filter, characterized in that it is formed from a rotating body. Formula [] M _x Mn _y (Si _p B _q CFP _s ) _z [In the above formula, M is 10at% with respect to Fe or Fe and Fe
1 of the following transition metal elements other than Fe and Mn
Represents a combination with more than one species, x+y+z=100at
%, of which y is 0.1 to 10at% and z is 16
~32at%. Furthermore, p+q+r+s=100%, of which p is 20 to 80%, s is 5% or less, and r/q is
It is 0.01-0.4. In addition, (1/5)p+6≦z≦−(1/2)p+67. ] The magnetic core for a noise filter according to claim 2, wherein 3s is 0.01 to 5%.