JP6013509B2 - Inductance component, magnetic bias applying member, and method of manufacturing magnetic bias applying member - Google Patents

Description

  The present invention relates to an inductance component, a magnetic bias applying member, and a method of manufacturing a magnetic bias applying member. In the present invention, the inductance component is a choke coil or a transformer used for a switching power supply or the like.

  Conventionally, an inductance component 800 including a magnetic core having a gap (gap) for preventing magnetic saturation in at least one part of a magnetic path and a conductive wire attached to the magnetic core is known.

  FIG. 11 is a diagram for explaining a conventional inductance component 800. FIG. 11A is a cross-sectional view of the inductance component 800, and FIG. 11B is a perspective view of the magnetic core 810.

  FIG. 12 is a view for explaining a conventional inductance component 800. FIG. 12A is a diagram showing a state of magnetic flux generated in the magnetic core 810 when a DC superimposed current flows through the conducting wire, and FIG. 12B is a graph schematically showing a BH curve of the inductance component 800. It is. In FIG. 12A, symbol D <b> 1 indicates the direction of the magnetic field generated in the magnetic path of the magnetic core 810 when a DC superimposed current flows through the conductor 820.

  As shown in FIG. 11, a conventional inductance component 800 includes a magnetic core 810 (magnetic core body 812) having a magnetic saturation prevention gap 816 at one position of a magnetic path, and a conductor (coil 820) mounted on the magnetic core. ). The conventional magnetic core 810 is formed, for example, by compression molding a soft magnetic material powder and a binder.

  The magnetic core 810 is configured by combining two E cores, and a magnetic core 818 having a gap 816 is formed at the center. In the magnetic core 810, two magnetic paths having the magnetic core 818 as a common part are formed.

  In the conventional inductance component 800, the gap length L of the air gap 816 is set in the range of several tens to several hundreds of micrometers in order to obtain desired magnetic characteristics (for example, DC superimposition characteristics and effective magnetic permeability). It is common.

  In the present specification, “DC superimposition” refers to superimposing a DC current on an AC current flowing through a lead wire of an inductance component. Further, the “DC superimposed current” refers to a DC current superimposed on an AC current flowing in the lead wire of the inductance component. The “DC superposition characteristic” means a characteristic that the magnetic core is hard to be magnetically saturated even when the DC superposition current becomes large. Therefore, “the DC superimposition characteristic is good” means that the magnetic core is hardly magnetically saturated even when the DC superimposition current is increased.

  Since the conventional inductance component 800 includes the magnetic core 810 having the magnetic saturation prevention air gap 816, the effective magnetic permeability of the magnetic core 810 is lower than that of the magnetic core without air gap. This is because the slope of the BH curve (solid line) in the case of the conventional magnetic core 810 having a gap is larger than the slope of the BH curve (dotted line) in the case of the magnetic core having no gap in FIG. It can be understood from the fact that is smaller. For this reason, compared with the case of an inductance component having a magnetic core without a gap, the magnetic core is less likely to be magnetically saturated even when the DC superimposed current becomes large, and the inductance component has good DC superimposed characteristics.

  Further, according to the conventional inductance component 800, since the magnetic core 810 having the magnetic saturation prevention gap 816 is provided, the effective permeability of the magnetic core 810 can be adjusted by adjusting the gap length L of the gap 816. It becomes possible. Therefore, an inductance component having desired magnetic characteristics can be obtained without changing the number of turns of the coil 820 and the material of the magnetic core 810.

  By the way, in the field of the technology of inductance parts in recent years, downsized inductance parts have been demanded with the demand for downsizing of electronic devices. However, when the inductance component is downsized as it is, the effective permeability of the magnetic core increases because the gap length L of the gap of the magnetic core also decreases. There is a problem that magnetic saturation easily occurs. For this reason, there is an increasing demand for an inductance component having a good direct current superposition characteristic even if it is downsized.

  In response to the above requirements, in general, it has been attempted to manufacture an inductance component having good DC superposition characteristics by using a magnetic core having high saturation magnetization. A magnetic core having a high saturation magnetization is formed by changing the type and composition of the magnetic core material. However, due to various problems such as limitations in changing the type and composition of the magnetic core material, it cannot be increased unnecessarily.

  In order to satisfy the above requirements, another conventional inductance component 900 using a so-called magnet bias system is known (see, for example, Patent Document 1).

FIG. 13 is a view for explaining another conventional inductance component 900. 13A is a cross-sectional view of the inductance component 900, and FIG. 13B is a perspective view of the magnetic core 910.
FIG. 14 is a view for explaining another conventional inductance component 900. FIG. 14A is a diagram illustrating a state of magnetic flux generated in the magnetic core 910 when a DC superimposed current flows through the conductor 920, and FIG. 14B schematically illustrates a BH curve of the inductance component 900. It is a graph.

  As shown in FIG. 13, another conventional inductance component 900 includes a magnetic core body 912 having a magnetic saturation prevention gap 916 at one position of the magnetic path, and a material different from the magnetic core body 912 provided in the gap 916. A magnetic core 910 having a magnetic bias applying member 914 and a conductive wire 920 attached to the magnetic core 910. The magnetic bias applying member 914 is formed by compression molding a hard magnetic material powder and an insulator into a flat plate shape.

  In another conventional inductance component 900, as shown in FIG. 14A, the direction D2 of the magnetic field by the magnetic bias applying member 914 is changed to the magnetic path of the magnetic core 910 by the DC superimposed current flowing through the conducting wire 920. A member 914 for applying a magnetic bias so that the direction D1 of the generated magnetic field is opposite (that is, a magnetic bias is applied in the direction opposite to the magnetic field generated by the DC superimposed current flowing through the conducting wire 920). Is arranged.

  According to another conventional inductance component 900, since the magnetic core 910 having the magnetic bias applying member 914 is provided, the magnetic field generated in the magnetic path of the magnetic core 910 by the DC superimposed current flowing through the conducting wire 920 is changed to the magnetic bias. It becomes possible to cancel by the magnetic field generated by the applying member 914. Accordingly, as shown in FIG. 14B, the other conventional magnetic core 910 has a magnetic flux density range ΔB (a usable magnetic flux density range) that does not reach the saturation magnetic flux density as compared with the conventional magnetic core 810. A large magnetic core. As a result, the magnetic core is less likely to be magnetically saturated even when the DC superimposed current is increased, resulting in an inductance component with good DC superimposed characteristics.

JP 50-133453 A

  Meanwhile, since the other conventional magnetic bias applying member 914 is formed of a hard magnetic material powder and an insulator, the relative permeability of the magnetic bias applying member 914 is approximately 1, and the conventional magnetic core 810 is provided. The relative permeability of the substance (air) existing between the air gaps 816 is substantially the same. Therefore, in order to make the magnetic characteristics (inductance, etc.) of another conventional inductance component 900 the same as that of the conventional inductance component 800, the gap length L of the air gap 916 in the magnetic core body 912 is changed to the conventional inductance. It is necessary to make the length approximately the same as the gap length L of the component 800.

  However, in another conventional inductance component 900, it is difficult to manufacture the magnetic bias applying member 914 having a thickness corresponding to the gap length L of the air gap 916 in the magnetic core body 912 with a small thickness variation. It may become. For example, when an attempt is made to produce a relatively thin magnetic bias application member having a thickness of about 300 μm or less by a press molding method using a relatively large magnetic material powder having an average particle size of about 150 μm as a raw material, a magnetic bias application with a small thickness variation Since it is difficult to manufacture a member for use, a member for applying a magnetic bias having a large thickness variation is produced.

  As a result, it becomes difficult to reduce the variation in the magnetic characteristics of the inductance component manufactured using the magnetic bias applying member having such a large variation in thickness. In other words, another conventional inductance component 900 has a problem that it is difficult to make an inductance component with small variations in magnetic characteristics.

  Accordingly, the present invention has been made to solve such a problem, and an object of the present invention is to provide an inductance component having good direct current superposition characteristics and small variations in magnetic characteristics. Another object of the present invention is to provide a magnetic bias applying member used for such an inductance component. Furthermore, it aims at providing the manufacturing method of the member for magnetic bias application which manufactures such a member for magnetic bias application.

[1] An inductance component according to the present invention includes a magnetic core body having a magnetic saturation prevention gap at least at one location of a magnetic path, and a magnetic bias application made of a material different from the magnetic core body disposed in the gap. A magnetic core having a magnetic member and a conductive wire attached to the magnetic core, the magnetic bias applying member comprising: a hard magnetic material powder for applying a magnetic bias; a soft magnetic material powder for improving a relative permeability; and It is formed by forming a composite magnetic material containing a binder that binds to a flat plate shape.

  In addition, a conducting wire should just be a wire used as the conductor for sending an electric current, and a composition, a shape, and thickness are not ask | required. Therefore, the conducting wire includes not only a coil shape in which a current flows, but also a linear shape, for example.

[2] In the inductance component of the present invention, it is preferable that the effective relative permeability of the magnetic core body constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member” is 10 or more.

  Here, the “magnetic path of the magnetic flux generated from the magnetic bias applying member” is a magnetic path through which the magnetic flux generated from the magnetic bias applying member penetrates the magnetic core body. In this case, magnetic flux does not penetrate the magnetic bias applying member.

[3] In the inductance component of the present invention, the effective relative permeability of the magnetic core body constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member” is “the magnetic force when a current is passed through the conducting wire”. It is preferably 1.5 times or more the effective relative permeability of the magnetic core constituting the “magnetic path of magnetic flux generated in the core”.

  Here, “the magnetic path of the magnetic flux generated in the magnetic core when a current is passed through the conducting wire” is a magnetic path through which the magnetic flux generated by using the conducting wire as a magnetomotive force penetrates the magnetic core, As well as a magnetic path through which the magnetic flux passes through the magnetic bias applying member.

[4] In the inductance component of the present invention, in the composite magnetic material, the ratio of the soft magnetic material powder to the total of the hard magnetic material powder and the soft magnetic material powder is in the range of 5 wt% to 80 wt%. It is preferable that it exists in.

[5] In the inductance component of the present invention, the inductance measured by changing the DC superimposed current flowing in the conductor in a graph in which the horizontal axis represents the DC superimposed current value and the vertical axis represents the inductance value of the inductance component. When the values are plotted, it is preferable that a curve indicating the relationship between the DC superimposed current and the inductance value indicates a plateau shape, and the plateau portion of the plateau shape is downwardly inclined.

  Here, the “mountain shape” of the above curve is a first region in which the DC superimposed current value is formed in a negative region and a positive region and the inductance value is substantially constant at a relatively low inductance value, and the first region. A shape formed of a second region (a plateau portion) formed in a region sandwiched between the regions and having a relatively high inductance value and the inductance value gradually changing (see FIG. 6 described later). In addition, “the plateau part is falling to the right” is not only when the plateau monotonously decreases from the left end, but also has a peak inductance value on the left end side of the plateau, and the right end side of the plateau part from the peak. Including the case of monotonically decreasing toward.

[6] In the inductance component of the present invention, in the magnetic bias applying member, the magnetization measured while changing the external magnetic field is plotted on the graph in which the horizontal axis represents the external magnetic field and the vertical axis represents the magnetization. When the external magnetic field is changed from 0 to a negative direction, the demagnetization curve of the JH curve indicating the relationship between the external magnetic field and the magnetization becomes a curve that gradually becomes gentler. Is preferable (see FIG. 9 described later).

[7] In the inductance component of the present invention, in the composite magnetic material, the soft magnetic material powder preferably has an average particle size in the range of 1 μm to 900 μm.

[8] In the inductance component of the present invention, the magnetic bias applying member has a relative magnetic permeability of 1.2 to 5.0 when the external magnetic field is not applied. It is preferable that it is comprised so that it may become.

[9] In the inductance component of the present invention, when the gap length of the gap in the magnetic core body is L, and the larger average particle diameter of the hard magnetic material powder and the soft magnetic material powder is D An inductance component that satisfies the following expression (1).

[10] In the inductance component of the present invention, the magnetic bias applying member is preferably made of a bonded magnet.

[11] In the inductance component of the present invention, the magnetic bias applying member is preferably made of a permanent magnet.

[12] In the inductance component of the present invention, the soft magnetic material powder is preferably subjected to an insulation treatment.

[13] In the inductance component of the present invention, the magnetic bias applying member is formed by pressing the composite magnetic material, injection molding the composite magnetic material, or forming the composite magnetic material by a green sheet method. It is preferably formed by any one of the methods.

[14] In the inductance component of the present invention, the magnetic core body is formed of ferrite or formed by molding a magnetic material containing a soft magnetic material powder and a binder. Preferably there is.

[15] A magnetic bias application member according to the present invention is a magnetic bias application member used for the inductance component according to any one of [1] to [14] above, a hard magnetic material powder for applying a magnetic bias, It is formed by molding a composite magnetic material containing a soft magnetic material powder for improving the relative magnetic permeability and a binder for binding them into a flat plate shape.

[16] A method for manufacturing a magnetic bias applying member according to the present invention is a method for manufacturing a magnetic bias applying member used in the inductance component according to any one of [1] to [14], wherein the magnetic bias applying member is used. A composite magnetic material preparation step for preparing a composite magnetic material by kneading a hard magnetic material powder, a soft magnetic material powder for improving relative permeability, and a binder for binding them in a predetermined ratio; A molding process for producing a molded body by molding into a shape, a curing process for curing the binder contained in the molded body, and a magnetization process for magnetizing the molded body to form a magnetic bias applying member. It is characterized by including in order.

  According to the inductance component of the present invention, since the magnetic core having the magnetic bias applying member is provided, the direct current superimposed current flows through the conducting wire in the magnetic path of the magnetic core as in the case of the other conventional inductance component 900. The generated magnetic field can be canceled out by the magnetic field of the magnetic bias applying member. For this reason, a magnetic core having a magnetic flux density range ΔB (a usable magnetic flux density range) that does not reach the saturation magnetic flux density is larger than that of the conventional magnetic core. As a result, the magnetic core is less likely to be magnetically saturated even when the DC superimposed current is increased, resulting in an inductance component with good DC superimposed characteristics.

  Further, according to the inductance component of the present invention, since the magnetic bias applying member is formed of a composite magnetic material containing a soft magnetic material powder for improving the relative permeability, the ratio of the magnetic bias applying member is The permeability can be made higher than 1. Here, in order to obtain a predetermined inductance value, the ratio between the relative permeability and the gap length of the air gap in the magnetic core body needs to be a constant ratio. If the relative permeability can be increased, the gap length is increased. It becomes possible to do. Therefore, the magnetic bias applying member having a thickness corresponding to the gap length can be manufactured with a small thickness variation. As a result, it is possible to reduce the variation in magnetic characteristics of the inductance component manufactured using the magnetic bias applying member having a small thickness variation.

  Further, according to the inductance component of the present invention, since the magnetic bias applying member is formed of a composite magnetic material containing a hard magnetic material powder and a soft magnetic material powder, the hard magnetic material and the soft magnetic material are used. It is possible to manufacture a member for applying a magnetic bias having desired magnetic characteristics by adjusting the ratio. As a result, the inductance component of the present invention becomes an inductance component having desired magnetic characteristics.

  Further, according to the inductance component of the present invention, the magnetic bias applying member is formed of a composite magnetic material containing a soft magnetic material powder for improving the relative permeability. It is possible to increase the magnetic permeability. For this reason, since the effective magnetic permeability of the entire magnetic core is increased, the number of turns of the coil (conductor) for obtaining a desired magnetic field strength can be reduced, and as a result, a high-performance inductance component with less core loss can be obtained. It becomes possible. In addition, since the relative permeability of the magnetic bias applying member can be increased, the magnetic field strength required to obtain a predetermined magnetic flux density in the air gap is higher than that of the other conventional inductance component 900. Therefore, it is possible to obtain a high-performance inductance component with little core loss.

  According to the magnetic bias applying member of the present invention, the magnetic bias applying member comprises a hard magnetic material powder for applying a magnetic bias, a soft magnetic material powder for improving the relative permeability, and a composite magnetic material containing a binder for binding them. Since it is formed by forming the material into a flat plate shape, it becomes a magnetic bias applying member having the above-described effects. As a result, it is possible to manufacture an inductance component having the effects described above.

  According to the method for manufacturing a magnetic bias applying member of the present invention, in the composite magnetic material manufacturing step, the hard magnetic material powder for applying the magnetic bias, the soft magnetic material powder for improving the relative magnetic permeability, and the binder for binding these are predetermined. Since the composite magnetic material is produced by kneading at a ratio of 1 to 5, it is possible to produce a member for applying a magnetic bias having the above-described effects. As a result, it is possible to manufacture an inductance component having the effects described above.

It is a figure shown in order to demonstrate the inductance component 1 which concerns on Embodiment 1. FIG. It is a figure shown in order to demonstrate the inductance component 1 which concerns on Embodiment 1. FIG. 3 is a flowchart shown for explaining a method for manufacturing a magnetic bias applying member according to the first embodiment. It is a figure shown in order to demonstrate the inductance component 2 which concerns on Embodiment 2. FIG. It is a figure shown in order to demonstrate the inductance component 3 which concerns on Embodiment 3. FIG. It is a graph which shows the direct current superposition characteristic of samples 1-3. It is a graph which shows the direct current superposition characteristic of samples 4-9. It is a graph which shows the direct current superposition characteristic of samples 10-15. It is a graph which shows the JH curve of the sample 16 and the sample 17. FIG. It is a graph which shows the demagnetization curve of samples 18-23. It is a figure shown in order to demonstrate the conventional inductance component 800. It is a figure shown in order to demonstrate the conventional inductance component 800. It is a figure shown in order to demonstrate other conventional inductance components 900. It is a figure shown in order to demonstrate other conventional inductance components 900.

  Hereinafter, an inductance component, a magnetic bias applying member, and a method of manufacturing a magnetic bias applying member according to the present invention will be described based on the embodiments shown in the drawings.

[Embodiment 1]
First, the configuration of the inductance component 1 according to the first embodiment will be described together with the configuration of the magnetic bias applying member 14 according to the first embodiment.
FIG. 1 is a diagram for explaining the inductance component 1 according to the first embodiment. 1A is a perspective view of the inductance component 1, FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A, and FIG. 1C is a perspective view of the magnetic core 10.

  As shown in FIG. 1A and FIG. 1B, the inductance component 1 according to Embodiment 1 includes a magnetic core 10 and a conductive wire 20 attached to the magnetic core 10.

  As shown in FIG. 1C, the magnetic core 10 includes a magnetic core body 12 having a magnetic saturation prevention gap 16 at least at one location of a magnetic path, and a magnetic core body 12 disposed in the gap 16. The magnetic bias applying member 14 is made of a different material.

  In the inductance component 1 according to the first embodiment, the effective relative permeability of the magnetic core body constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member” is 10 or more (for example, 630). The effective relative permeability of the magnetic core main body constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member” is “the magnetic path of the magnetic flux generated in the magnetic core 10 when a current is passed through the conducting wire 20”. It is 1.5 times or more of the effective relative magnetic permeability (for example, 80) of the magnetic core which comprises.

  As shown in FIG. 2A, which will be described later, the magnetic core body 12 is composed of two E cores combined so that the magnetic core 18 is formed at the center, and the magnetic core 818 is a common part. Two magnetic paths are formed.

As the magnetic core main body 12, for example, a powder made of iron oxide as a main component is compressed and molded, and then formed from a sintered ceramic ferrite, or a soft magnetic material powder and a binder are molded. The formed one can be used.
As the soft magnetic material powder, an appropriate one such as FeSiCr powder, FeSi powder, carbonyl iron powder, sendust powder, permalloy powder, MnZn ferrite powder, or amorphous material powder can be used, or a combination of these materials. It can also be used.

  The air gap 16 is formed in the magnetic core 18 which is one place of the magnetic path. The gap length of the air gap 16 (the air gap 16 of the magnetic core body 12) is the effective magnetic path length (for example, 7.5 cm) of the magnetic path (the magnetic path of the magnetic flux generated in the magnetic core when a current is passed through the conducting wire). 5% or less, for example, 500 μm.

The gap 16 has a gap length L of the magnetic core body 12 of L, and a larger average particle diameter of hard magnetic material powder and soft magnetic material powder of the magnetic bias applying member 14 described later is D. The following formula (1) is satisfied.

  The magnetic bias applying member 14 is disposed in the gap 16 of the magnetic core body 12. Specifically, the direction D2 of the magnetic field generated by the magnetic bias applying member 14 is opposite to the direction D1 of the magnetic field generated in the magnetic core 10 when a DC superimposed current flows through the conductive wire 20 (that is, the conductive wire). 20 is arranged so that a magnetic bias is applied in the direction opposite to the magnetic field generated in the magnetic core 10 by the direct current superimposed current flowing in the magnetic core 10.

  The magnetic bias applying member 14 is made of a material different from that of the magnetic core body 12 and is formed by molding a composite magnetic material, which will be described later, into a flat plate shape (specifically, by pressing the composite magnetic material). It has been done. The magnetic bias applying member 14 is a permanent magnet and a bonded magnet.

  The thickness of the magnetic bias applying member 14 has a thickness corresponding to the gap length L of the air gap 16 in the magnetic core body 12 and is, for example, 500 μm in the first embodiment.

  The magnetic bias applying member 14 is configured such that the relative permeability of the magnetic bias applying member 14 when no external magnetic field is applied is in the range of 1.2 to 5.0.

なお、式（２）において、μは、磁気バイアス印加用部材１４の比透磁率を示し、Ｂｓは磁気コア本体１２の飽和磁束密度を示し、Ｊは磁気コア本体１２の磁化を示し、μ_０は真空の透磁率を示し、Ｈｃは磁気バイアス印加用部材１４の保磁力を示す。In the magnetic bias applying member 14, the relative permeability of the magnetic bias applying member 14 satisfies the following expression (2). With this configuration, the magnetic bias applying member 14 can be prevented from being demagnetized by a reverse pulse current.

In Expression (2), μ represents the relative permeability of the magnetic bias applying member 14, Bs represents the saturation magnetic flux density of the magnetic core body 12, J represents the magnetization of the magnetic core body 12, and μ ₀ Indicates the magnetic permeability of vacuum, and Hc indicates the coercive force of the magnetic bias applying member 14.

The composite magnetic material contains a hard magnetic material powder for applying a magnetic bias, a soft magnetic material powder for improving the relative magnetic permeability, and a binder for binding them. As an additive for heat dissipation, alumina (Al ₂ O ₃ ) powder, aluminum nitride (AlN) powder, or the like may be further included.

  The soft magnetic material powder is a soft magnetic material powder whose surface is covered with a silica film (insulated). The soft magnetic material powder may be any magnetic material powder having a high magnetic permeability, for example, FeSiCr powder, FeSi powder, ferrite powder, carbonyl iron powder, sendust powder, permalloy powder, or amorphous material powder should be used. Can do. In the first embodiment, FeSiCr powder is used. The average particle size of the soft magnetic material powder is in the range of 1 μm to 900 μm, preferably in the range of 1 μm to 100 μm, and more preferably in the range of 1 μm to 50 μm.

  In the composite magnetic material, the ratio of the soft magnetic material powder to the total of the hard magnetic material powder and the soft magnetic material powder is in the range of 5 wt% to 80 wt%, preferably in the range of 10 wt% to 20 wt%. Yes, for example, 20 wt%.

  The hard magnetic material powder is a hard magnetic material powder whose surface is covered with a silica film (insulated). The hard magnetic material powder may be any magnetic material powder having a high coercive force, such as samarium cobalt (SmCo) powder, samarium iron nitrogen (SmFeN) powder, neodymium iron boron (NdFeB) powder, or ferrite powder. The hard magnetic material powder can be used. In Embodiment 1, samarium cobalt (SmCo) powder is used. The average particle size of the hard magnetic material powder is in the range of 1 μm to 900 μm, preferably in the range of 1 μm to 100 μm, and more preferably in the range of 1 μm to 50 μm.

  In the composite magnetic material, the ratio of the hard magnetic material powder to the total of the hard magnetic material powder and the soft magnetic material powder is in the range of 20 wt% to 95 wt%, preferably in the range of 80 wt% to 90 wt%. Yes, for example, 75 wt%.

The binder is made of a polymer and binds the hard magnetic material powder and the soft magnetic material powder. As the binder, for example, an appropriate one can be used as long as it is a thermosetting resin or a thermoplastic resin such as an epoxy resin, a polyimide resin, a polyamideimide resin, a silicone resin, or a phenol resin.
The content of the binder in the composite magnetic material varies depending on the method for manufacturing the magnetic bias applying member, but when the magnetic bias applying member 14 is manufactured by pressing the composite magnetic material, for example, 1 wt% to 5 wt. % Is preferably in the range of%.

  In the case where the magnetic bias applying member 14 is formed by press molding the composite magnetic material, if the binder content in the composite magnetic material is less than 1 wt%, the ratio of the binder is too small and hard magnetic It is difficult to join between the material powder and the soft magnetic material powder. Further, when the content of the binder in the composite magnetic material exceeds 5 wt%, the content of the hard magnetic material powder and the soft magnetic material powder is decreased, so that the relative permeability of the magnetic bias applying member 14 is reduced, The magnetic flux density range ΔB that does not reach the saturation magnetic flux density may be smaller than other conventional magnetic cores.

  In the magnetic bias applying member 14, when the magnetization measured while changing the external magnetic field H is plotted on the graph with the external magnetic field H on the horizontal axis and the magnetization J on the vertical axis, the external magnetic field H and the magnetization J are plotted. The demagnetization curve of the J-H curve indicating the relationship between the external magnetic field H and the external magnetic field H changes from 0 to a negative direction so that the gradient gradually decreases (see FIG. 9 described later). . That is, the magnetic bias applying member 14 has a property that the relative magnetic permeability gradually decreases when the external magnetic field H is changed from 0 to a negative direction.

Next, the operation of the inductance component 1 according to the first embodiment will be described.
FIG. 2 is a diagram for explaining the inductance component 1 according to the first embodiment. 2A is a diagram showing a state of magnetic flux generated in the magnetic core 10 when a current is passed through the conductor 20, and FIG. 2B is a graph schematically showing a BH curve of the inductance component 1. FIG. It is. In FIG. 2A, the symbol D1 indicates the direction of the magnetic field generated in the magnetic core 10 when a DC superimposed current flows through the conductor 20, and the symbol D2 indicates the direction of the magnetic field by the magnetic bias applying member 14. .

  In the inductance component 1 according to the first embodiment, when a DC superimposed current is passed through the conducting wire 20, a magnetic field is generated in the magnetic path of the magnetic core 10 as shown in FIG. In the inductance component 1, when the DC superimposed current is out of a predetermined DC superimposed current value range (about −2 A to about +14 A in the sample 1 of FIG. 6 described later), magnetic saturation occurs, and the inductance decreases rapidly. .

  In the inductance component 1 according to the first embodiment, the inductance value measured while changing the DC superimposed current flowing in the conductor 20 in a graph in which the horizontal axis represents the DC superimposed current value and the vertical axis represents the inductance value of the inductance component. Is plotted, the curve indicating the relationship between the DC superimposition current and the inductance value indicates the plateau shape, and the plateau portion of the plateau shape is lowered to the right.

  This is considered to be because the relative magnetic permeability of the magnetic bias applying member 14 gradually decreases when the external magnetic field is changed from 0 to a negative direction.

Next, the manufacturing method of the inductance component according to the first embodiment will be described by dividing into “preparation of magnetic core body”, “manufacture of magnetic bias applying member”, and “attachment of magnetic bias applying member”.
FIG. 3 is a flowchart for explaining the method for manufacturing the magnetic bias applying member according to the first embodiment.

2-1. Preparation of Magnetic Core Body First, a magnetic core body 12 having a magnetic saturation prevention gap 16 at one location of a magnetic path is prepared. In the magnetic core body 12, the air gap 16 may be formed after forming the magnetic core body without the air gap, or the E core considering the air gap 16 is formed in advance, and the air gap 16 is also formed by combining the E core. You may be made to do.

2-2. Manufacture of Magnetic Bias Application Member A method of manufacturing a magnetic bias application member includes, as shown in FIG. And in this order.

(1) Composite magnetic material production process First, a hard magnetic material powder for applying a magnetic bias, a soft magnetic material powder for improving relative permeability, and a binder for binding them are kneaded at a predetermined ratio to produce a composite magnetic material. To do. Next, the composite magnetic material is dried to volatilize the solvent component in the binder. Next, the composite magnetic material is sieved, and only the composite magnetic material having a particle size suitable for molding (within a range of several tens of μm to several hundreds of μm) is recovered.

(2) Molding process Next, a compact is produced by molding the composite magnetic material into a flat plate shape. Specifically, a composite magnetic material is deposited in a molding space and press-molded to produce a molded body. Pressing pressure in the pressing mold is within a range of, for example, ^{3ton / cm 2 ~10ton / cm 2} . The temperature at the time of press molding shall be room temperature.

(3) Curing step Next, the molded body is heated to cure the binder. Although the temperature and time which heat a molded object are based also on the kind of binder, it shall be 1 hour at 150 degreeC, for example.

(4) Magnetization Step Next, the molded body in which the binder is cured is magnetized to obtain a magnetic bias applying member 14. Specifically, the compact is magnetized using a pulse magnetizer.
In this way, the magnetic bias applying member 14 can be manufactured.

2-3. Mounting of Magnetic Bias Application Member Next, the magnetic core 10 is manufactured by disposing the magnetic bias application member 14 in the gap 16 in the magnetic core body 12. Next, the conducting wire 20 is attached to the magnetic core 10.
As a result, the inductance component 1 according to the first embodiment can be manufactured.
When assembling the E core, the inductance component 1 according to the first embodiment may be manufactured by assembling the E core with the magnetic bias applying member 14 interposed therebetween.

  Next, effects of the inductance component 1 according to the first embodiment, the magnetic bias applying member 14 according to the first embodiment, and the manufacturing method of the magnetic bias applying member according to the first embodiment will be described.

  According to the inductance component 1 according to the first embodiment, since the magnetic core 10 having the magnetic bias applying member 14 is provided, a DC superposed current flows through the conductive wire 20 as in the case of other conventional inductance components 900. The magnetic field generated in the magnetic path of the magnetic core 10 can be canceled by the magnetic field of the magnetic bias applying member 14. For this reason, a magnetic core having a magnetic flux density range ΔB (a usable magnetic flux density range) that does not reach the saturation magnetic flux density is larger than that of the conventional magnetic core. As a result, the magnetic core 10 is less likely to be magnetically saturated even when the DC superimposed current becomes large, and the inductance component has good DC superimposed characteristics.

  Further, according to the inductance component 1 according to the first embodiment, the magnetic bias applying member 14 is formed of a composite magnetic material containing a soft magnetic material powder for improving the relative permeability. The relative permeability of the working member 14 can be made higher than 1. Here, in order to obtain a predetermined inductance value, the ratio between the relative permeability and the gap length L of the air gap 16 in the magnetic core body 12 needs to be a constant ratio, and if the relative permeability can be increased, the gap The length L can be increased. Therefore, the magnetic bias applying member 14 having a thickness corresponding to the gap length L can be manufactured with a small thickness variation. As a result, it is possible to reduce the variation in magnetic characteristics of the inductance component manufactured using the magnetic bias applying member having a small thickness variation.

  Further, according to the inductance component 1 according to the first embodiment, the magnetic bias applying member 14 is formed of a composite magnetic material containing a hard magnetic material powder and a soft magnetic material powder. It is possible to manufacture a magnetic bias applying member having desired magnetic characteristics by adjusting the ratio between the magnetic material and the soft magnetic material. As a result, the inductance component 1 becomes an inductance component having desired magnetic characteristics.

  In addition, according to the inductance component 1 according to the first embodiment, the magnetic bias applying member 14 is formed of a composite magnetic material containing a soft magnetic material powder for improving the relative permeability. It is possible to increase the relative permeability of the working member 14. For this reason, since the effective magnetic permeability of the entire magnetic core 10 is increased, the number of turns of the conducting wire 20 (coil) for obtaining a desired magnetic field strength can be reduced, and as a result, a high-performance inductance component with less core loss is obtained. It becomes possible. In addition, since the relative permeability of the magnetic bias applying member 14 can be increased, the magnetic field strength necessary for obtaining a predetermined magnetic flux density in the air gap 16 is different from that in the case of the other conventional inductance component 900. Compared with this, it is possible to obtain a high-performance inductance component with little core loss.

  According to the inductance component 1 according to the first embodiment, since the effective relative permeability of the magnetic core body constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member” is 10 or more, a desired DC superposition characteristic is obtained. It becomes an inductance component having. When the effective relative permeability of the magnetic core body constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member 14” is less than 10, the demagnetizing field becomes stronger, and the magnetic bias is applied. The effect of the magnetic bias by the working member becomes weak, and it becomes difficult to obtain an inductance component having a desired DC superposition characteristic. From this point of view, the effective relative permeability of the “magnetic path of the magnetic flux generated from the magnetic bias applying member 14” is preferably 100 or more, and more preferably 500 or more.

  According to the inductance component 1 according to the first embodiment, the effective relative permeability of the magnetic core body 12 constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member 14” is “when a current is passed through the conducting wire 20”. Since the effective relative permeability of the magnetic core 10 constituting the “magnetic path of the magnetic flux generated in the magnetic core 10” is 1.5 times or more, the inductance component having a better DC superposition characteristic is obtained. Note that the effective relative permeability of the magnetic core body 12 constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member 14” is the magnetic path of the magnetic flux generated in the magnetic core 10 when a current is passed through the conducting wire 20. Is less than 1.5 times the effective relative permeability of the magnetic core 10 constituting the magnetic field, the effect of the magnetic bias by the magnetic bias applying member is weakened due to the strong demagnetizing field, and the DC superposition characteristics However, it is difficult to obtain a good inductance component. From this point of view, the magnetic core constituting the magnetic path of the magnetic flux generated in the magnetic core 10 when the effective relative permeability of the “magnetic path of the magnetic flux generated from the magnetic bias applying member 14” is passed through the conductor 20. The effective relative permeability of 10 is preferably 2 times or more, and more preferably 3 times or more.

  Further, according to the inductance component 1 according to the first embodiment, in the composite magnetic material, the ratio of the soft magnetic material powder to the total of the hard magnetic material powder and the soft magnetic material powder is in the range of 5 wt% to 80 wt%. Therefore, it becomes an inductance component having the above-described effect, and a magnetic core having the magnetic bias applying member 14 with sufficient magnetic field strength.

  In the composite magnetic material, the ratio of the soft magnetic material powder to the total of the hard magnetic material powder and the soft magnetic material powder is “within the range of 5 wt% to 80 wt%”. This is because when the amount is less than 5 wt%, the amount of soft magnetic material powder is too small to obtain the above-mentioned effect. When the proportion of soft magnetic material powder exceeds 80 wt%, the proportion of hard magnetic material powder This is because the magnetic bias applying member 14 cannot obtain a sufficient magnetic field strength.

  In addition, according to the inductance component 1 according to the first embodiment, measurement is performed while changing the DC superimposed current flowing through the conductor 20 in a graph in which the horizontal axis represents the DC superimposed current value and the vertical axis represents the inductance value of the inductance component. When the measured inductance value is plotted, the curve indicating the relationship between the DC superimposed current and the inductance value indicates the plateau shape, and the plateau portion of the plateau is downwardly inclined. As a result, the ripple current of the conducting wire 20 is reduced and the power supply efficiency is improved. In addition, since the inductance value is smaller at the time of heavy load than at the time of light load, the responsiveness is improved when the current flowing through the conducting wire changes abruptly. As a result, the power supply efficiency can be improved at light loads, and the inductance component can improve responsiveness when the current flowing through the conductor changes suddenly at heavy loads.

  Here, “under light load” means a time when a relatively light load is applied such that the DC superimposed current value is close to 0 (about −3 to 3 A), and “under heavy load” , When the load is applied so that the DC superimposed current value is larger than the light load, specifically, out of the plateau part of the curve showing the relationship between the DC superimposed current and the inductance value It means that a load is applied to the extent that the DC superposition current value is in the range of about 1/3 of the right end side of the plateau in the range of 0 A or more.

  It should be noted that since the ripple current of the conductor 20 is increased due to a decrease in the inductance value at the time of heavy load, it seems that the power supply efficiency is lowered. However, when the load is heavy, the DC superimposed current is extremely large compared to the ripple current, so that the influence of the large ripple current on the power supply efficiency is small.

  In addition, according to the inductance component 1 according to the first embodiment, in the magnetic bias applying member 14, the demagnetization curve of the JH curve indicating the relationship between the external magnetic field H and the magnetization J has a negative external magnetic field from zero. Therefore, when the external magnetic field is close to 0 (that is, the DC superimposed current in the inductance component is 0). When the external magnetic field increases in the negative direction (that is, the DC superimposed current in the inductance component increases in the positive direction), the relative magnetic permeability gradually decreases. For this reason, when the external magnetic field is close to 0, the inductance value is large, and the inductance component gradually decreases. As a result, the power supply efficiency can be improved at light loads, and the inductance component can improve responsiveness when the current flowing through the conductor changes suddenly at heavy loads.

  Further, according to the inductance component 1 according to the first embodiment, in the composite magnetic material, since the average particle size of the soft magnetic material powder is in the range of 1 μm to 900 μm, it is possible to prevent a decrease in magnetization, In addition, the magnetic bias applying member 14 can be manufactured with a small thickness variation.

  In the composite magnetic material, the soft magnetic material powder has an average particle diameter in the range of 1 μm to 900 μm. When the average particle diameter is less than 1 μm, the soft magnetic material powder and the binder are kneaded. This is because the soft magnetic material powder is oxidized and the decrease in magnetization becomes remarkable. When the average particle diameter exceeds 900 μm, the particle diameter with respect to the gap length L of the air gap 16 in the magnetic core body 12 is large. This is because it is difficult to manufacture the magnetic bias applying member 14 with a small thickness variation.

  In addition, according to the inductance component 1 according to the first embodiment, the relative permeability of the magnetic bias applying member 14 when no external magnetic field is applied is in the range of 1.2 to 5.0. The applying member 14 can be manufactured with a small thickness variation, and the magnetic bias applying member 14 is an inductance component that can obtain a sufficient magnetic field strength.

  In the composite magnetic material, the relative permeability of the magnetic bias applying member 14 when no external magnetic field is applied is in the range of 1.2 to 5.0. When the magnetic permeability is less than 1.2, the magnetic bias applying member 14 having a thickness corresponding to the gap length L of the air gap 16 in the magnetic core body 12 is increased as in the case of the other conventional inductance component 900. This is because it is difficult to manufacture in a state where the variation in the thickness is small. When the relative permeability of the magnetic bias applying member 14 exceeds 5.0, the inductance value of the inductance component becomes too small, so that the power supply efficiency This is because of the decrease. From this viewpoint, the relative magnetic permeability of the magnetic bias applying member 14 is preferably in the range of 1.2 to 3.0, and more preferably in the range of 1.4 to 2.0.

Further, according to the inductance component 1 according to the first embodiment, the gap length of the air gap 16 in the magnetic core body 12 is L, and the larger average particle diameter of the hard magnetic material powder and the soft magnetic material powder is D. When the following equation (1) is satisfied, a magnetic bias applying member having a thickness corresponding to the gap length L can be manufactured with a small thickness variation. As a result, it is possible to reduce variations in magnetic characteristics of manufactured inductance components.

  The reason why the gap length L of the air gap 16 in the magnetic core body 12 is not less than the value on the right side of the equation (1) is as follows. That is, when a structure is formed by arranging particles in three or more rows in a close-packed hexagonal structure, the thickness variation of the structure can be made relatively small. Even when the magnetic bias applying members are arranged in rows or more (the magnetic bias applying members are equal to or larger than the value on the right side of the equation (1) at this time), the thickness variation of the magnetic bias applying members is relatively small. it can. Therefore, in order for the magnetic bias applying member to be equal to or greater than the value on the right side of Equation (1), the gap length L may be equal to or greater than the value on the right side of Equation (1).

  Further, according to the inductance component 1 according to the first embodiment, since the magnetic bias applying member is made of a bonded magnet, the magnetic bias applying member 14 has flexibility. As a result, it is possible to prevent the end of the magnetic core main body 12 and the end of the magnetic bias applying member 14 from being chipped when the magnetic bias applying member 14 is disposed in the gap 16.

  Further, according to the inductance component 1 according to the first embodiment, since the magnetic bias applying member 14 is a permanent magnet, the magnetic bias applying member 14 that can keep a magnetic field for a relatively long period of time is obtained. For this reason, it is possible to manufacture an inductance component having a long life.

  In addition, according to the inductance component 1 according to the first embodiment, since the soft magnetic material powder is subjected to the insulation treatment, the magnetic bias applying member 14 is less likely to generate eddy current and less eddy current loss. As a result, an inductance component with low core loss is obtained.

  In addition, according to the inductance component 1 according to the first embodiment, the magnetic bias applying member 14 is formed by press-molding a composite magnetic material, and thus depends on the type of material included in the composite magnetic material. It is possible to easily form the magnetic bias applying member 14 without using it.

  Further, according to the magnetic bias applying member 14 according to the first embodiment, the magnetic bias applying member 14 combines the hard magnetic material powder for applying the magnetic bias, the soft magnetic material powder for improving the relative permeability, and these. Since it is formed by molding a composite magnetic material containing a binder into a flat plate shape, it is possible to manufacture an inductance component with good DC superposition characteristics, and the gap 16 in the magnetic core body 12 can be produced. It is possible to manufacture a magnetic bias applying member having a thickness corresponding to the gap length with a small variation in thickness, and to manufacture a magnetic bias applying member having desired magnetic characteristics, and Thus, the magnetic bias applying member can be made into a high-performance inductance component with little core loss.

  According to the method for manufacturing a magnetic bias applying member according to the first embodiment, in the composite magnetic material manufacturing step S10, the hard magnetic material powder for applying the magnetic bias, the soft magnetic material powder for improving the relative magnetic permeability, and these are combined. Since the composite magnetic material is produced by kneading the binder at a predetermined ratio, the magnetic bias applying member 14 having the above-described effect can be produced.

[Embodiment 2]
FIG. 4 is a diagram for explaining the inductance component 2 according to the second embodiment. 4A is a perspective view of the inductance component 2, and FIG. 4B is a perspective view of the magnetic core 10a.

  The inductance component 2 according to the second embodiment is an inductance component 1 according to the first embodiment in that the magnetic core has a member for applying a magnetic bias formed of a composite magnetic material containing a hard magnetic material powder and a soft magnetic material powder. The configuration of the magnetic core body is different from that of the inductance component 1 according to the first embodiment. That is, in the inductance component 2 according to the second embodiment, the magnetic core body 12a is a ring core as shown in FIG.

  In the inductance component 2 according to the second embodiment, when a DC superimposed current flows through the conducting wire 20a, a magnetic field is generated so as to go around the magnetic core 10a. That is, the magnetic core 10a has one closed magnetic path.

  In the inductance component 2 according to the second embodiment, as shown in FIG. 4A, the conducting wire 20a is attached to the magnetic core 10a by being spirally wound around the magnetic core 10a.

  As described above, the inductance component 2 according to the second embodiment is different from the inductance component 1 according to the first embodiment in the configuration of the magnetic core body, but similarly to the inductance component 1 according to the first embodiment, the magnetic component is magnetic. Since the bias applying member 14 is formed of a composite magnetic material containing a hard magnetic material powder for applying a magnetic bias and a soft magnetic material powder for improving relative permeability, the direct current superposition characteristics are good, In addition, the inductance component has a small variation in magnetic characteristics.

  The inductance component 2 according to the second embodiment has the same configuration as the inductance component 1 according to the first embodiment except for the configuration of the magnetic core body. Of which, it has a corresponding effect.

[Embodiment 3]
FIG. 5 is a diagram for explaining the inductance component 3 according to the third embodiment. FIG. 5A is a perspective view of the inductance component 3, and FIG. 5B is a perspective view of the magnetic core 10b.

  The inductance component 3 according to the third embodiment is an inductance component 2 according to the second embodiment in that the magnetic core has a member for applying a magnetic bias formed of a composite magnetic material containing a hard magnetic material powder and a soft magnetic material powder. However, the configuration of the magnetic core body and the configuration of the conducting wire are different from those of the inductance component 2 according to the second embodiment. That is, in the inductance component 3 according to the third embodiment, the magnetic core 10b is composed of two U cores combined in a ring shape as shown in FIG. 5, and the conductive wire 20b has an elongated flat plate shape. It is attached to the magnetic core 10b so as to penetrate straight through the center of the magnetic core 10b.

  In the magnetic core body 12b, the two air gaps 16b are provided at positions corresponding to the joint portions of the two U cores, and the magnetic bias applying member 14b is also located one by one at a position between the two U cores. It is arranged.

  As described above, the inductance component 3 according to the third embodiment is different from the inductance component 2 according to the second embodiment in the configuration of the magnetic core body and the configuration of the conductive wire, but the inductance component 2 according to the second embodiment. Similarly, since the magnetic bias applying member 14 is formed of a composite magnetic material containing a hard magnetic material powder for applying a magnetic bias and a soft magnetic material powder for improving relative permeability, the DC superposition characteristics And an inductance component with small variations in magnetic characteristics.

  The inductance component 3 according to the third embodiment has the same configuration as that of the inductance component 2 according to the second embodiment except for the configuration of the magnetic core main body and the configuration of the conductive wire, and thus the inductance component 2 according to the second embodiment. Has the corresponding effect among the effects of

[Test Example 1]
In Test Example 1, the inductance component of the present invention is “the inductance component having good DC superimposition characteristics” and “the curve indicating the relationship between the DC superimposition current and the inductance value indicates the plateau shape, and the plateau shape This is a test example showing that the plateau part of the plate is downwardly inclined to the right.

1. Sample Preparation (1) Sample 1 (Example)
A sample having the same inductance component as that of the inductance component 2 according to the second embodiment except for having a gap in two places was prepared as a sample 1. However, in Sample 1, the outer diameter of the ring core is 31 mm, the inner diameter of the ring core is 19 mm, the height of the ring core is 8 mm, the average effective magnetic path length of the ring core is 78.5 mm, and the effective cross-sectional area is 48 mm ^2. The effective volume was 3769.9 mm ³ . Further, two gaps were provided at symmetrical positions in the ring core, and the gap length L of each gap was 0.5 mm. Furthermore, in the magnetic bias applying member of Sample 1, the entire composite magnetic material is 100 wt%, SmCo as the hard magnetic material powder is 80 wt%, FeSiCr as the soft magnetic material powder is 17 wt%, and the binder is 3 wt%. A composite magnetic material was used.

(2) Sample 2 (comparative example)
Except for the point that the gap length L of the gap in the ring core is 0.3 mm and the configuration that the magnetic bias applying member is not provided in the gap, the same inductance component as that of the sample 1 is produced, and the sample 2 is obtained. .

(3) Sample 3 (comparative example)
For magnetic bias application formed by compression molding a composite magnetic material containing a hard magnetic material powder and a binder as a magnetic bias application member at the point and gap where the gap length L of the air gap in the ring core is 0.3 mm Except for the point of disposing the member, the same inductance component as that of the sample 1 was prepared as Sample 3. The magnetic bias applying member of Sample 3 was a composite magnetic material in which SmCo as the hard magnetic material powder was 97 wt% and the binder was 3 wt% when the entire composite magnetic material was 100 wt%.

2. Evaluation method Obtained by plotting the inductance value measured while changing the DC superimposed current flowing in the lead wire of each sample on the graph with the DC superimposed current value on the horizontal axis and the inductance value of the inductance component on the vertical axis. The DC superposition characteristics were evaluated from the curved shape and inductance value.

3. Evaluation Results FIG. 6 is a graph showing the DC superposition characteristics of Samples 1 to 3.
(1) Description of FIG. 6 In sample 1, the DC superimposed current value is approximately constant at an inductance value of about 5 μH or less up to about −6 A, and the inductance value is between about −6 A to −2 A. From about 5 μH or less to about 42 μH, the DC superposition current gradually increases from about −2 A to +1 A, and the inductance value gradually increases from about 42 μH to about 46 μH, and the DC superposition current ranges from about +1 A to +14 A. The inductance value gradually decreases from about 46 μH to about 38 μH, the DC superimposed current decreases rapidly from about +14 A to +18 A, and the inductance value decreases rapidly from about 38 μH to about 8 μH, and the DC superimposed current is about +18 A or more and about 8 μH or less. The inductance value was almost constant. The peak of the inductance value was about 46 μH when the DC superimposed current was about + 1A.

  In sample 2, although illustration is omitted, the inductance value of 5 μH or less is almost constant until the DC superimposed current value is about −12.5 A, and the inductance is between about −12.5 A to −8 A. The value suddenly increases from about 5 μH or less to about 42 μH, the inductance value slightly increases from about 43 μH to about 46 μH while the DC superimposed current is about −8 A to 0 A, and the DC superimposed current is about 0 A to +8 A. The inductance value slightly decreases from about 46 μH to about 42 μH, the DC superimposed current decreases rapidly from about +8 A to +14 A, and the inductance value decreases rapidly from about 42 μH to about 8 μH, and the DC superimposed current is about +14 A or more. It became almost constant at an inductance value of 5 μH or less. The peak of the inductance value was about 46 μH when the DC superimposed current was about 0A.

  In the sample 3, the DC superposition current value is approximately constant at an inductance value of about 5 μH or less until about −6 A, and the inductance value suddenly increases from about 5 μH to about 42 μH when the DC superposition current is between about −6 A to 0 A. The inductance value increases slightly from about 42 μH to about 46 μH when the DC superimposed current is about 0 A to +7 A, and the inductance value slightly increases from about 46 μH to about 38 μH when the DC superimposed current is about 7 A to +16 A. The inductance value suddenly decreased from about 38 μH to about 8 μH when the DC superimposed current was between about +16 A to +18 A, and became substantially constant at an inductance value of 5 μH or less when the DC superimposed current was about +18 A or more. The peak of the inductance value was about 46 μH when the DC superimposed current was about +7 A.

(2) DC superimposition characteristics In sample 2, as described above, since the inductance value drastically decreased from about 38 μH to 5 μH or less when the DC superposition current was between about +8 A and +14 A, the member for applying magnetic bias in sample 2 Is considered that the DC superposition current is magnetically saturated between about +8 A to +14 A. On the other hand, in the sample 1 (and 3), as described above, the inductance value suddenly increased from 38 μH during the period when the DC superimposed current was about +15 A to +18 A (between about +16 A and +18 A in the sample 3). Therefore, the magnetic bias applying member in sample 1 (and 3) is considered to be magnetically saturated when the DC superimposed current is between about +15 A and +18 A (between about +17 A and +18 A in sample 3). . Therefore, in sample 1 (and 3), the DC superposition current when magnetically saturated is between about +15 A and +18 A (in sample 3, between about +16 A and +18 A), and in the case of sample 2 (about +8 A). To + 14A), it was confirmed that it was large.

  From this, it was confirmed that Sample 1 (and 3) was an inductance component having better DC superposition characteristics than Sample 2.

(3) Regarding the curve showing the relationship between the DC superimposed current and the inductance value As can be seen from the above “(1) Description of FIG. 6”, in each of Samples 1 to 3, the relationship between the DC superimposed current and the inductance value is used. The curve which shows has shown the plateau shape.
In Sample 3, as described above, after the inductance value reaches its peak, the inductance value is about 46 μH to about 42 μH between about 7 A and +14 A (ie, while 7 A increases). 4 μH decreased gently. On the other hand, in the sample 1, after the inductance value reaches the peak, the inductance value gently decreases from about 46 μH to about 38 μH when the DC superimposed current is between about 1 A to +14 A (that is, 13 A increases). did.

  From this, in the sample 1, it has confirmed that the curve which shows the relationship between a direct current | flow superimposition electric current and an inductance value showed plateau shape, and the plateau part of plateau shape was falling to the right.

  Therefore, since the inductance value of Sample 1 is larger than that of Sample 3 at light load, the power supply efficiency can be improved compared to Sample 3, and the inductance value is smaller than that of Sample 3 at heavy load. Therefore, it was found that this is an inductance component capable of improving the responsiveness when the current flowing through the conductor changes more rapidly than the sample 3.

  In Sample 3, when the magnetic bias applying member was manufactured, the magnetic bias applying member having a thickness of 0.3 mm could not be manufactured only by the compression molding method. For this reason, the magnetic bias application member is once made thick (for example, about 1 mm), and the magnetic bias application member thus prepared is ground and thinned to a predetermined thickness so that the magnetic bias application according to the sample 3 is applied. The member for manufacture was manufactured. However, it is not easy to grind and thin the magnetic bias applying member according to the sample 3 to a thickness of 0.3 mm, and a defective product is generated due to a crack or the like, or the thickness of the magnetic bias applying member according to the sample 3 is reduced. Since there was a large error, there was very little that could be put to practical use.

[Test Example 2]
Test Example 2 is that “the inductance component of the present invention has an inductance value larger than that of a conventional inductance component”, “the inductance component of the present invention has the largest inductance value at a light load”, and “ The inductance component of the present invention is a test example showing that the plateau portion in the curve of the DC superimposition characteristic falls to the right, and that the inclination of the plateau portion becomes gentler as the magnetic bias applying member is strongly magnetized.

1. Sample preparation

(1) Sample 4 (Comparative Example) and Samples 5-9 (Example)
Magnetic bias application using a composite magnetic material in which SmCo as a hard magnetic material powder is 77 wt%, FeSiCr as a soft magnetic material powder is 20 wt%, and a binder is 3 wt% when the entire composite magnetic material is 100 wt% Samples 4 to 9 were prepared by producing six inductance components that are the same as the inductance component 2 according to the second embodiment except that the member is used and the number of turns of the conducting wire (coil) is 10. However, samples 4 to 9 have residual magnetizations of 0%, 20%, 40%, 60%, and 80, respectively, when the residual magnetization when the magnetic bias applying member is magnetized so as to be saturated is 100%. % And 100% of the magnetic bias applying member is used.

(2) Samples 10 to 15 (comparative example)
When the entire composite magnetic material is 100 wt%, six inductance components are manufactured in the same manner as the sample 4 except that a magnetic material with SmCo as the hard magnetic material powder of 97 wt% and a binder of 3 wt% is used. Samples 10 to 15. However, Samples 10 to 15 have residual magnetizations of 0%, 20%, 40%, 60%, and 80, respectively, when the residual magnetization when the magnetic bias applying member is magnetized so as to be saturated is 100%. % And 100% of the magnetic bias applying member is used.

2. Evaluation Method On the graph with the DC superimposed current value taken on the horizontal axis and the inductance value taken on the vertical axis, the inductance value measured while changing the DC superimposed current flowing through the lead wire of the sample was plotted, and the shape of the curve obtained and The DC superposition characteristics were evaluated from the inductance value.

3. Evaluation result (1) “Inductance value of the inductance component of the present invention is larger than that of the conventional inductance component” FIG. 7 is a graph showing the DC superposition characteristics of Samples 4-9.
FIG. 8 is a graph showing the DC superposition characteristics of Samples 10-15.

  As can be seen from FIG. 8, the peak values of the inductance values in Samples 10 to 15 (corresponding to other conventional inductance components 900) are around 17 μH. On the other hand, as can be seen from FIG. 7, the peak value of the inductance value in samples 5 to 9 (corresponding to the inductance component of the present invention) is 20.5 to 22.5 μH, both of which are conventional inductance components. It was confirmed that it was larger than.

  Therefore, it was confirmed that the inductance component of the present invention has a larger inductance value than the conventional inductance component. This means that the inductance component of the present invention is an inductance component with high power supply efficiency.

(2) “The inductance component of the present invention has the largest inductance value at light load”

As can be seen from FIG. 8, the curve indicating the DC superimposition characteristic of the sample 15 is a state where the DC superposition current value of the sample 10 is shifted by 8 A in the positive direction. For example, the DC superimposed current value when the inductance value in the sample 15 takes a peak is 8A, which is 8A shifted from the DC superimposed current value (0A) when the inductance value in the sample 10 takes a peak. For this reason, it was found that the peak of the inductance value in the sample 15 was out of the range of the DC superimposed current value corresponding to the light load.
On the other hand, as can be seen from FIG. 7, the DC superposed current value when the inductance value in Samples 5 to 9 (corresponding to the inductance component of the present invention) takes a peak is 0 A to 1 A. It was found that the inductance value peak at 9 was in the range of the DC superimposed current value corresponding to the light load.

  Therefore, in the inductance component of the present invention, it was confirmed that the inductance value was the largest when the load was light. This means that the inductance component of the present invention is an inductance component that can further improve the power supply efficiency when the load is light.

(3) Regarding the inductance component of the present invention, the plateau portion in the curve of the DC superimposition characteristic is lowered to the right, and the inclination of the plateau portion becomes gentler as the magnetic bias applying member is strongly magnetized.

  As can be seen from FIG. 7, it was confirmed that the plateau portion of the DC superimposition characteristics curve of Samples 5 to 9 was lowered to the right.

Further, as can be seen from FIG. 7, the curve indicating the DC superimposition characteristic of sample 4 (comparative example) shows a peak (23.5 μH) inductance value when the DC superimposition current value is 0 A, and the DC superimposition current value. Is 6A, the right end of the plateau portion of the curve showing the DC superposition characteristics (inductance value is 20.5 μH). Therefore, the ratio of the change of the inductance value with respect to the DC superimposed current from the peak of the inductance value to the right end of the plateau is about −0.5 (3 μH / 6A).
On the other hand, in the curve of the DC superposition characteristics of Samples 5 to 9 (examples, corresponding to the inductance components of the present invention), the inductance with respect to the DC superposition current between the peak of the inductance value and the right end of the plateau. The rate of change of the values is −0.43 (3.5 μH / 8A), −0.38 (3 μH / 8A), −0.25 (2 μH / 8A), and −0.20 (2 μH / 10A), respectively. , −0.15 (1 μH / 10 A), and it was found that the absolute value of the rate of change gradually decreased. From this, it was found that the inclination of the plateau portion becomes gentler as the magnetic bias applying member is strongly magnetized.

  Therefore, it has been confirmed that the inductance part of the present invention has a plateau portion in the DC superimposition characteristic curve that lowers to the right, and the inclination of the plateau portion becomes gentler as the magnetic bias application member is strongly magnetized. . This means that the inductance component of the present invention can improve the power supply efficiency when the load is light, and can improve the response when the current flowing through the conductor changes suddenly when the load is heavy. In addition to being an inductance component, this means that the inductance component is a stable inductance component with little sudden change in inductance.

[Test Example 3]
Test Example 3 shows that in the magnetic bias application member of the present invention, “the demagnetization curve of the JH curve is such that the slope gradually decreases when the external magnetic field H is changed from 0 to the negative direction. It is a test example showing that it consists of a simple curve.

1. Sample Preparation (1) Sample 16 (Example)
After preparing the same magnetic bias applying member as the magnetic bias applying member 14 according to the first embodiment, the sample 16 was magnetized to 100%. However, the effective area was 48 mm ² and the thickness was 0.5 mm. Further, a composite magnetic material was used in which the entire composite magnetic material was 100 wt%, SmCo as the hard magnetic material powder was 80 wt%, FeSiCr as the soft magnetic material powder was 17 wt%, and the binder was 3 wt%.
(2) Sample 17 (comparative example)
The magnetic bias is the same as that of the magnetic bias applying member used in Sample 16, except that the composite magnetic material is 100 wt%, and the composite magnetic material is 97 wt% SmCo as the hard magnetic material powder and 3 wt% binder. An application member was prepared and used as Sample 17.

2. Evaluation Method Magnetic bias from the curve shape obtained by plotting the magnetization measured while changing the external magnetic field H for each sample on the graph with the external magnetic field H on the horizontal axis and the magnetization J on the vertical axis The magnetic properties of the application member were evaluated.

3. Evaluation Results FIG. 9 is a graph showing JH curves of Sample 16 and Sample 17.
As can be seen from FIG. 9, in Sample 17, the slope of the JH curve gradually increased when the external magnetic field was changed from 0 (kA / m) to the negative direction. On the other hand, in Sample 16, the slope of the JH curve gradually decreased when the external magnetic field was changed from 0 (kA / m) to the negative direction.

  From this, it can be confirmed that for the sample 16, the demagnetization curve of the JH curve is a curve whose slope gradually decreases when the external magnetic field H is changed from 0 to the negative direction. It was.

  Therefore, it was found that the sample 16 has a high relative magnetic permeability when the external magnetic field is close to 0 (kA / m), and the relative magnetic permeability gradually decreases as the external magnetic field increases in the negative direction. Therefore, it was found that the sample 16 had a large inductance value when the external magnetic field was close to 0 (kA / m), and the inductance value gradually decreased as the external magnetic field increased in the negative direction.

[Test Example 4]
In Test Example 4, even when the content of the soft magnetic material powder in the composite magnetic material powder was changed, the “JH curve demagnetization curve reduced the external magnetic field H to 0 in the magnetic bias applying member of the present invention. It is a test example showing that the curve is such that the slope gradually becomes gentle when changing from negative to negative.

1. Sample Preparation (1) Samples 18-22 (Examples)
After producing the same magnetic bias applying member as the magnetic bias applying member 14 according to the first embodiment, the samples 18 to 22 were produced by being 100% magnetized. Here, assuming that the entire composite magnetic material is 100 wt%, SmCo as a hard magnetic material powder is 87 wt%, 77 wt%, 67 wt%, 57 wt%, 47 wt%, and FeSiCr as a soft magnetic material powder is 10 wt%, 20 wt%, 30 wt%. Samples 18, 19, 20, 21, and 22 were obtained using composite magnetic materials having%, 40 wt%, 50 wt%, and 3 wt% binder, respectively. However, the effective area was 48 mm ² and the thickness was 0.5 mm.
(2) Sample 23 (comparative example)
The configuration is the same as that of the magnetic bias applying member 14 according to the first embodiment except that the total composite magnetic material is 100 wt%, and the hard magnetic material powder is a composite magnetic material having 97 wt% SmCo and 3 wt% binder. A member for applying a magnetic bias was prepared and used as Sample 23.

2. Evaluation Method By plotting the magnetization measured while changing the external magnetic field H for each sample on a graph (excluding the second quadrant) with the external magnetic field H on the horizontal axis and the magnetization J on the vertical axis. The magnetic characteristics of the magnetic bias applying member were evaluated from the obtained curve shape.

3. Evaluation Results FIG. 10 is a graph showing the demagnetization curves of the JH curves of Samples 18-23.
As can be seen from FIG. 10, in the sample 23, the slope gradually increased when the external magnetic field was changed from 0 (kA / m) to the negative direction. On the other hand, in the sample 18, when the external magnetic field is changed from 0 (kA / m) to the negative direction, the inclination gradually decreases, and the inclination gradually decreases again from around -520 (kA / m). It became bigger. In Samples 19 to 22, the inclination gradually decreased when the external magnetic field was changed from 0 (kA / m) to the negative direction.

  From this, even if the content of the soft magnetic material powder in the composite magnetic material powder is changed, the samples 18 to 22 show that the demagnetization curve of the JH curve changes the external magnetic field H from 0 to the negative direction. It was confirmed that the curve was such that the slope gradually decreased.

  Therefore, even when the content of the soft magnetic material powder in the composite magnetic material powder is changed, the relative magnetic permeability increases when the external magnetic field is close to 0 (kA / m), and the external magnetic field increases in the negative direction. It was found that the relative permeability gradually decreased. For this reason, it was found that the samples 18 to 22 had a large inductance value when the external magnetic field was close to 0 (kA / m), and gradually decreased as the external magnetic field increased in the negative direction.

  As mentioned above, although this invention was demonstrated based on said embodiment, this invention is not limited to said embodiment. The present invention can be implemented in various modes without departing from the spirit thereof, and for example, the following modifications are possible.

(1) The number, positional relationship, and size of each component in each of the above embodiments are examples, and the present invention is not limited to this.

(2) In the first embodiment, the case where the magnetic core body is composed of two E cores, the case where the magnetic core body is composed of a ring core in the second embodiment, and the ring shape in the third embodiment. Although the present invention has been described by way of examples of two U cores combined in such a manner, the present invention is not limited to this. For example, even when an EI core combining an E-type core and an I-type core, a rod-like core shaped like a bar extending in one direction, or another core is used as the magnetic core. Is applicable.

(3) In each of the above embodiments, the present invention has been described by taking as an example the case where the magnetic bias applying member is formed by pressing a composite magnetic material. However, the present invention is not limited to this. It is not something. For example, the present invention can be applied if the magnetic bias applying member is a construction method that can be formed into a flat plate shape even when a composite magnetic material is injection molded, when a green sheet method is used, or when other methods are used. It is. In this case, the binder content may be appropriately adjusted.

(4) In each of the above embodiments, the present invention has been described by taking the case of an inductance component using a magnetic bias applying member having a thickness corresponding to the gap length of the air gap of the magnetic core body as an example. It is not limited to. For example, the present invention can be applied even when a magnetic bias applying member thinner than the thickness corresponding to the gap length of the gap of the magnetic core body is used.

  In this case, a magnetic bias applying member and an air gap exist in the gap. The gap length of the air gap is 5% or less of the effective magnetic path length of the magnetic core body constituting the magnetic path (the magnetic path of the magnetic flux generated in the magnetic core when a current is passed through the conducting wire). preferable. By adopting such a configuration, the magnetic core is less likely to be magnetically saturated due to the shortening of the gap length of the air gap, and hence the magnetic bias effect is less likely to be reduced, and the DC superposition characteristics are excellent. It becomes a part. From this point of view, the gap length of the air gap in the magnetic core body is preferably 3% or less of the effective magnetic path length of the magnetic path, and more preferably 1% or less of the effective magnetic path length of the magnetic path.

  1, 2, 3... Inductance parts 10, 10a, 10b ... Magnetic core, 12, 12a, 12b ... Magnetic core body, 14, 14a, 14b ... Magnetic bias applying member, 16, 16a, 16b ... Air gap, 18 ... Magnetic core, 20, 20a, 20b ... conducting wire

Claims (13)

A magnetic core body having a magnetic saturation prevention gap in at least one location of the magnetic path; and a magnetic core having a magnetic bias application member made of a material different from the magnetic core body disposed in the gap;
A conductive wire mounted on the magnetic core;
The magnetic bias applying member is formed by molding a hard magnetic material powder for applying a magnetic bias, a soft magnetic material powder for improving relative permeability, and a composite magnetic material containing a binder for binding them into a flat plate shape. der thing was is,
The soft magnetic material powder is FeSiCr powder, FeSi powder, carbonyl iron powder and Sendust powder, or a combination thereof,
The surface of the soft magnetic material powder is covered with an insulating film,
The inductance component, wherein the hard magnetic material powder is one of samarium cobalt (SmCo) powder, samarium iron nitrogen (SmFeN) powder, neodymium iron boron (NdFeB) powder, or a combination thereof. The inductance component according to claim 1,
An inductance component, wherein an effective relative permeability of a magnetic core body constituting a “magnetic path of a magnetic flux generated from a magnetic bias applying member” is 10 or more. The inductance component according to claim 2,
The effective relative magnetic permeability of the magnetic core body constituting the “magnetic path of the magnetic flux generated from the magnetic bias applying member” constitutes the “magnetic path of the magnetic flux generated in the magnetic core when a current is passed through the conducting wire” An inductance component characterized by being 1.5 times or more the effective relative permeability of the magnetic core. In the inductance component according to any one of claims 1 to 3,
In the composite magnetic material, the ratio of the soft magnetic material powder to the total of the hard magnetic material powder and the soft magnetic material powder is in the range of 5 wt% to 80 wt%. In the inductance component according to any one of claims 1 to 4,
In the composite magnetic material, the soft magnetic material powder has an average particle diameter in the range of 1 μm to 900 μm. In the inductance component according to any one of claims 1 to 5,
The magnetic bias applying member is configured such that a relative permeability of the magnetic bias applying member when an external magnetic field is not applied is in a range of 1.2 to 5.0. Inductance parts to be used. In the inductance component according to any one of claims 1 to 6,
When the gap length of the gap in the magnetic core body is L and the larger average particle diameter of the hard magnetic material powder and the soft magnetic material powder is D, the following formula (1) is satisfied. Inductance parts characterized by

In the inductance component according to any one of claims 1 to 7,
The magnetic bias applying member is a bonded magnet. In the inductance component according to any one of claims 1 to 8,
The inductance component, wherein the magnetic bias applying member is a permanent magnet. In the manufacturing method of the inductance component according to any one of claims 1 to 9
The magnetic bias applying member is formed by any one of a method of press molding the composite magnetic material, a method of injection molding of the composite magnetic material, or a method of molding the composite magnetic material by a green sheet method. A method for manufacturing an inductance component , characterized in that : In the manufacturing method of the inductance component in any one of Claims 1-10 ,
The magnetic core main body, or those formed by ferrite, or a method of manufacturing an inductance component, characterized in that one formed by molding a magnetic material containing soft magnetic material powder and a binder . A manufacturing method of a magnetic bias application members used in the inductance component according to any one of claims 1 to 11
It is formed by molding a hard magnetic material powder for applying a magnetic bias, a soft magnetic material powder for improving relative permeability, and a composite magnetic material containing a binder for binding them into a flat plate shape. A method for manufacturing a magnetic bias applying member. A manufacturing method of a magnetic bias application members used in the inductance component according to any one of claims 1 to 11
A composite magnetic material preparation step of preparing a composite magnetic material by kneading a hard magnetic material powder for applying a magnetic bias, a soft magnetic material powder for improving the relative permeability, and a binder for binding them at a predetermined ratio;
A molding step for producing a molded body by molding the composite magnetic material into a flat plate shape,
A curing step for curing the binder contained in the molded body;
A method of manufacturing a member for applying magnetic bias, comprising the step of magnetizing the molded body to form a member for applying magnetic bias in this order.

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