JP2011114085A - Magnetic wire material and inductor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic wire material capable of achieving miniaturization and reducing heat loss to prevent inductance reduction, regardless of using the material for a power-system equipment. <P>SOLUTION: An inductor 1 has a drum-type core member 10 and a magnetic wire material 20 wound on the core member 10. The magnetic wire material 20 has a conducting wire 21, a conductive magnetic body layer 22 formed on an outer periphery surface of the conducting wire 21, and an insulating layer 23 formed on the outer periphery surface of the conductive magnetic body layer 22. The magnetic wire material 20 has an annular groove 25 formed along a radial direction. In addition, the conductive magnetic body layer 22 has an outer surface 22a in a roughening state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a magnetic wire and an inductor, and more particularly to a magnetic wire and an inductor used in power system equipment such as a reactor, a motor, and a transformer.

  Conventionally, in various industrial fields such as automobiles, home appliances, robots / instrumentation, and communication, inductors in which a coil is wound are used. Among such inductors, in the communication field, a high-frequency inductor is used in which a copper wire having a protective coating on its surface is wound around an air-core coil. At low frequencies, in order to increase the inductance, a method of reducing the wire diameter of the air-core coil or increasing the number of turns is employed. When the inductance is too large, a lead wire is wound around the bobbin, a magnetic body is provided inside the coil to increase the inductance, and the relative position between the magnetic body and the coil is changed to adjust the inductance.

  Here, when the wire diameter of the air-core coil is reduced, there is a problem that as the wire diameter is reduced, the insertability into the circuit board is lowered, the strength of the wire is lowered, and the coil shape is easily changed. Further, when the number of turns is increased, there is a problem that the rigidity of the air-core coil is lowered and the coil shape is easily changed.

  In order to solve such a problem, a high-frequency inductor composed of an air core coil and a copper wire wound around the air core coil and having a magnetic film on the surface has been proposed. A copper wire having a magnetic film on its surface has a higher relative magnetic permeability than a copper wire having a protective film on its surface. Therefore, the diameter can be increased and the number of turns can be reduced as compared with an inductor having an equivalent inductance, and thus the inductance can be increased while reducing the number of work steps (Patent Document 1).

JP 62-211904 A

  However, when the inductor as described above is used in a power system device such as a reactor, a motor, or a transformer, an eddy current is generated in a layer (conductive layer) formed by the magnetic film, so that the amount of heat generated due to the eddy current loss. There is a problem that it increases and causes a decrease in inductance. In order to reduce heat loss, a method of mixing particles such as iron oxide in the protective coating (insulating layer) can be considered, but there is a problem that the insulating property is lowered. In recent years, with the power saving and downsizing of products, there is an increasing demand for higher efficiency and downsizing of inductors.

  An object of the present invention is to provide a magnetic wire material and an inductor capable of realizing miniaturization and reducing heat loss and preventing a decrease in inductance even when used in power equipment. .

  In order to achieve the above object, a magnetic wire according to the present invention is a magnetic wire comprising a conductive wire and a conductive magnetic material structure formed on a surface of the conductive wire, wherein the conductive magnetic material structure has the conductive property. It has at least 1 part which suppresses that the eddy current which generate | occur | produces in a magnetic body layer advances to the longitudinal direction of the said magnetic wire.

  Preferably, the conductive magnetic structure is composed of a conductive magnetic layer provided discontinuously along the longitudinal direction of the magnetic wire.

  Preferably, the magnetic wire includes at least one groove formed along a direction substantially perpendicular to the longitudinal direction of the magnetic wire, and the conductive magnetic layer has the at least one groove formed. Thus, the magnetic wires are discontinuously provided along the longitudinal direction.

  Preferably, the conductive magnetic layer or the conductive wire has a roughened outer surface.

  More preferably, the maximum height Rz of the outer surface is ½ or more of the maximum thickness of the conductive magnetic layer.

  Preferably, the conductive magnetic body structure includes a plurality of protrusions formed on the surface of the conducting wire.

  Preferably, the conductive magnetic body structure is made of a permalloy alloy.

  Preferably, the magnetic wire further includes an insulating layer formed on an outer surface of the conductive magnetic structure.

  In order to achieve the above object, an inductor according to the present invention includes a core member and a magnetic wire wound around the core member, and the core member includes a predetermined number of turns of the magnetic wire. The magnetic wire comprises a conductive wire and a conductive magnetic layer formed on the surface of the conductive wire, and the conductive magnetic structure is formed in the conductive magnetic layer. It has at least 1 part which suppresses that the eddy current which generate | occur | produces in a longitudinal direction of the said magnetic wire progresses.

  Preferably, the conductive magnetic structure is composed of a conductive magnetic layer provided discontinuously along the longitudinal direction of the magnetic wire.

  Preferably, the magnetic wire includes at least one groove formed along a direction substantially perpendicular to the longitudinal direction of the magnetic wire, and the at least one groove exists per turn of the winding.

  Preferably, the conductive magnetic layer or the conductive wire has a roughened outer surface.

  Preferably, the core member further includes flange portions provided at both ends of the shaft portion.

  According to the magnetic wire of the present invention, the conductive magnetic structure has at least one portion that suppresses the eddy current generated in the conductive magnetic layer from proceeding in the longitudinal direction of the magnetic wire. An increase in current loss can be prevented, and an increase in heat generation can be suppressed. Therefore, even when the magnetic wire is used for a power system device, it is possible to reduce the heat loss and prevent the inductance from decreasing while realizing the downsizing of the inductor.

  In addition, since the outer surface of the conductive magnetic structure is roughened, the eddy current can be prevented from proceeding in the longitudinal direction in the conductive magnetic layer, and the increase in eddy current can be suppressed. it can. Moreover, since the area of the outer surface of a conductive magnetic body increases, heat dissipation can be improved.

  Further, according to the inductor of the present invention, the magnetic wire having the conductive magnetic body structure having at least one portion for suppressing the eddy current from proceeding in the longitudinal direction of the magnetic wire is wound around the shaft portion. Leakage magnetic flux can be reduced in the vicinity of the magnetic wire of the inductor, and the magnetic resistance is reduced compared to the case where a core member having the same capacity and a wire having the same size and no conductive magnetic layer are used. can do. Therefore, even when the inductor is used in a power system device, it is possible to reduce the heat loss and prevent the inductance from being reduced while realizing the downsizing of the inductor.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematically the structure of the inductor and magnetic wire which concern on embodiment of this invention, (a) is sectional drawing of an inductor, (b) is sectional drawing of a magnetic wire. It is a figure which shows the magnetic wire of FIG. 1, (a) is a perspective view, (b) is sectional drawing, (c) is a fragmentary sectional view. It is a schematic diagram explaining the flow of the magnetic flux in the inductor of FIG. It is a figure which shows the relationship between the frequency of an inductor, and an inductance. It is a figure which shows the modification of the magnetic wire of FIG. 1, (a) is a perspective view, (b) is sectional drawing. It is a figure which shows the modification of the inductor of FIG. 1, (a) shows a 1st modification, (b) shows a 2nd modification.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  1A and 1B are diagrams schematically showing configurations of an inductor and a magnetic wire according to an embodiment of the present invention. FIG. 1A is a cross-sectional view of the inductor, and FIG. 1B is a cross-sectional view of the magnetic wire.

  In FIG. 1A, the inductor 1 includes a drum-type core member 10 and a magnetic wire 20 wound around the core member 10.

  The core member 10 includes a substantially cylindrical shaft portion 11 and disk-shaped flange portions 12 and 13 provided at both ends of the shaft portion 11. The core member 10 is made of a magnetic material, for example, ferrite. As this ferrite, for example, Mn—Zn ferrite, Ni—Zn ferrite, Cu—Zn ferrite or the like can be used. The length of the shaft portion 11 is, for example, 11.85 mm, and the outer diameter thereof is, for example, 7.65φ.

  The magnetic wire 20 includes a conductive wire 21, a conductive magnetic layer (conductive magnetic structure) 22 formed on the outer peripheral surface of the conductive wire 21, and an insulating layer 23 formed on the outer peripheral surface of the conductive magnetic layer 22. (FIG. 1B). The magnetic wire 20 is wound between the outer peripheral portion of the shaft portion 11 and the flange portions 12 and 13, and the number of turns is, for example, 90 turns. The outer diameter of the magnetic wire 20 is, for example, φ0.7 to 0.75.

  The conducting wire 21 is made of copper, and its outer diameter is, for example, φ0.55. The conductive magnetic layer 22 is made of a permalloy alloy and has a thickness of, for example, 1.0 μm. Preferably, the conductive magnetic layer 22 is made of a Ni—Mo—Cu—Fe permalloy alloy. In addition, as a permalloy alloy, PB material (40-50 wt% Ni) prescribed | regulated by JISC2531, PC material (70-85 wt% Ni-Mo-Cu-Fe), PD material (35-40 wt% Ni-Fe) ) And the like, and a PC material is preferable. The insulating layer 23 is made of enamel, for example, and has a thickness of 35 to 100 μm, for example.

  2A and 2B are diagrams showing the magnetic wire 20 of FIG. 1, where FIG. 2A is a perspective view, FIG. 2B is a cross-sectional view, and FIG. 2C is a partial cross-sectional view.

  As shown in FIGS. 2A and 2B, the magnetic wire 20 has an annular groove 25 formed along the radial direction. The width of the annular groove 25 may be a size that can be electrically insulated in the longitudinal direction in order to suppress the eddy current in the longitudinal direction of the magnetic wire, but is as short as possible because it is necessary to pass a magnetic field generated from the coil. Is preferred. The thickness of the conductive magnetic layer 22 is preferably 0.1 to 2.0 μm. When the thickness is less than 0.1 μm, the thickness is insufficient as a passage through which magnetic flux flows, and when the thickness is greater than 2.0 μm, the thickness becomes hard, and the flexibility as a coil wire is lowered, making winding difficult. . Further, the annular groove portions 25 are provided at a predetermined interval with respect to the longitudinal direction of the magnetic wire 20, and the conductive magnetic layer 22 is provided along the longitudinal direction of the magnetic wire 20 by providing the annular groove portions 25 at a predetermined interval. And discontinuously provided on the surface of the conducting wire 21. Further, the annular groove portion 25 is formed so that at least one annular groove portion exists per one turn of the winding.

  In general, when an alternating current flows through an inductor around which a magnetic wire is wound, an alternating magnetic field (magnetic field) H is generated so as to cross the vicinity of the center of the conductive magnetic layer in the thickness direction. At this time, an eddy current is generated on the outer surface of the conductive magnetic layer. The generated eddy current travels on the outer surface of the conductive magnetic layer along the longitudinal direction of the magnetic wire, moves to the inner surface of the conductive magnetic layer at the end of the magnetic wire, and then the conductive magnetic layer. Proceeds in the opposite direction on the inner surface of and returns to its original position. At this time, since the conductive magnetic layer is continuously formed along the longitudinal direction of the magnetic wire, an eddy current having a large flow is generated. Due to the generation of eddy current having a large flow, eddy current loss increases, and as a result, the heat generation amount increases. Such a phenomenon becomes conspicuous when used in power system equipment such as a reactor, a motor, and a transformer.

  Therefore, in the present embodiment, the annular groove 25 is provided in the conductive magnetic layer 22, and the conductive magnetic layer 22 is formed discontinuously with respect to the longitudinal direction of the magnetic wire 20. Thereby, the eddy current which generate | occur | produces in the electroconductive magnetic body layer 22 can be suppressed, and the increase in the emitted-heat amount can be suppressed.

  Further, as shown in FIG. 2C, the conductive magnetic layer 22 may have an outer surface 22a in a roughened state. This roughened state refers to a state in which the outer surface 22a has surface roughness due to fine irregularities. More specifically, there are a plurality of irregularities in the length of 100 μm on the cross section of the conductive magnetic layer 22, and the maximum height Rz of the convex portion of the outer surface 22 a is the maximum thickness of the conductive magnetic layer 22. It shows that it is 1/2 or more of Lmax. For example, when the thickness of the conductive magnetic layer 22 is 1.0 μm, the maximum height Rz of the outer surface 22a is 0.5 μm or more. At this time, it becomes difficult for the eddy current generated in the conductive magnetic layer 22 to flow at a position where the maximum height is exhibited. Therefore, it is possible to suppress the eddy current from proceeding in the longitudinal direction within the conductive magnetic layer 22 and to suppress an increase in electrical resistance. In addition, when the outer surface 22a of the conductive magnetic layer 22 is roughened, the area of the outer surface increases, so that the heat dissipation can be improved.

  Furthermore, in the present embodiment, the conductive magnetic material structure is composed of a conductive magnetic material layer. However, the present invention is not limited to this, and it is a structure that can suppress the eddy current from proceeding in the longitudinal direction of the magnetic wire. Anything may be used. For example, a conductive magnetic body structure having a predetermined surface roughness may be configured by forming a plurality of fine bump-like projections (unevenness) made of a conductive magnetic body on the surface of the conductive wire 21. In this case, for example, the plurality of fine ridge-like protrusions are fixed so that the plurality of conductive magnetic fine particles having a diameter of about 0.1 to 3.0 μm have a plurality of irregularities in the length of 10 μm in the cross section of the conductor 21. Thus, the same effect can be achieved by forming a roughened layer structure as a whole.

  The effect of the present invention can also be achieved by roughening the surface of the conductive wire 21 and further forming a film made of a conductive magnetic material on the surface.

  FIG. 3 is a schematic diagram for explaining the flow of magnetic flux in the inductor 1 of FIG.

  As shown in FIG. 3, a part of the magnetic flux generated in the inductor 1 moves from the flange portion 12 of the core member to the conductive magnetic layer 22 in the magnetic wire 20 located in the vicinity of the flange portion. Thereafter, the magnetic flux travels through the conductive magnetic layers of the adjacent magnetic wires in order and reaches the flange 13. That is, the magnetic flux travels between the flanges 12 and 13 through the conductive magnetic layer 22 made of a material having a high magnetic permeability at the shortest distance. As a result, the leakage magnetic flux generated in the vicinity of the magnetic wire 20 of the inductor 1 can be reduced, compared with the case where a core member having the same capacity and a wire having the same size and no conductive magnetic layer are used. Thus, the magnetic resistance can be reduced. Therefore, a high relative magnetic permeability can be maintained and a decrease in inductance can be prevented.

  The magnetic wire and the inductor configured as described above are manufactured as follows.

  First, a drum core made of Ni—Zn ferrite having a shaft portion length of 11.85 mm and a shaft portion outer diameter of 7.65φ is prepared. Next, a permalloy alloy film (conductive magnetic layer) having a surface roughness of 1.0 μm in thickness is formed on a copper wire having an outer diameter of φ0.55 by a pulse plating method using a PC material. Thereafter, an insulating coating (insulating layer) having a thickness of 100 μm is applied to produce a permalloy alloy-coated wire (conductive magnetic material-coated wire) having an outer diameter of φ0.65 to 0.75. Furthermore, annular grooves are formed at predetermined intervals on the outer surface of the wire, and the permalloy alloy film is formed discontinuously in the longitudinal direction of the wire. At this time, the value of the predetermined interval is determined so that at least one annular groove exists in one turn in a state where the annular groove is wound around the core. Then, the magnetic wire is wound around the drum core at about 90 turns to produce an inductor using the permalloy alloy-coated wire.

  Next, as a comparative example, a 1.0 μm nickel conductive film is formed on a copper wire having an outer diameter of φ0.55, and further an insulating coating having a thickness of 100 μm is applied to form a nickel having an outer diameter of φ0.65 to 0.75. A coated wire is produced, and an inductor wound with the nickel-coated wire is produced. Further, as another comparative example, a normal wire inductor is manufactured by forming a wire material in which a conductive film is not formed on a copper wire having an outer diameter of .phi.0.55 and only an insulating coating is applied, and this wire material is wound.

  And about each inductor, the inductance Ls with respect to a predetermined frequency is measured. The relationship between the inductor frequency and the inductance Ls is shown in FIG.

  As shown in FIG. 4, the inductance Ls of the inductor using the permalloy alloy-coated wire is increased by about 9% with respect to the inductor using the nickel-coated wire at any frequency, and is about 17 for the normal inductor. % Increase. From this result, when the permalloy alloy-coated wire is used, the inductance can be increased as compared with the case where the nickel-coated wire is used or the wire where no conductive film is formed. Moreover, when it is desired to obtain the same inductance with the core member having the same shape and the same size, the number of windings can be reduced and the DC resistance of the coil can be reduced by using the permalloy alloy-coated wire.

  As described above, according to the present embodiment, since the conductive magnetic layer 22 is discontinuously provided along the longitudinal direction of the magnetic wire 20, the eddy current generated in the conductive magnetic layer 22 is not generated. Propagation along the longitudinal direction of the layer can be suppressed, an increase in eddy current loss can be prevented, and an increase in calorific value can be suppressed. Therefore, even when the magnetic wire 20 is used in a power system device, it is possible to reduce the heat loss and prevent the inductance from being reduced while realizing the downsizing of the inductor.

  Further, according to the present embodiment, the magnetic wire 20 in which the conductive magnetic layer 22 is provided discontinuously along the longitudinal direction of the magnetic wire is wound around the shaft portion 11. The leakage magnetic flux generated in the vicinity of 20 can be reduced, and the magnetic resistance is reduced as compared with the case where the core member having the same capacity and the wire having the same dimensions and having no conductive magnetic layer are used. be able to. Therefore, even when the inductor 1 is used in a power system device, it is possible to reduce the heat loss and prevent the inductance from decreasing while realizing the downsizing of the inductor.

  FIG. 5 is a view showing a modification of the magnetic wire 20 in FIG. 1, (a) is a perspective view, and (b) is a cross-sectional view.

  As shown in FIG. 5, the magnetic wire 50 includes a conducting wire 51 having a substantially rectangular cross section, a conductive magnetic layer 52 formed on any one of four surfaces along the longitudinal direction of the conducting wire 51, and a conducting wire 51. And an insulating layer 53 formed on the outer peripheral surface of the conductive magnetic layer 52. Further, the magnetic wire 50 has an annular groove 55 formed along a direction substantially perpendicular to the longitudinal direction, and the conductive magnetic layer 52 and the insulating layer 53 are formed on the surface of the conducting wire 51 with respect to the longitudinal direction. Provided discontinuously.

  According to this modification, even if the magnetic wire has a substantially rectangular cross section, it is possible to reduce heat loss and prevent a decrease in inductance. Therefore, it is possible to use magnetic wires having different cross-sectional shapes depending on the application.

  6A and 6B are diagrams showing a modification of the inductor 1 in FIG. 1, where FIG. 6A shows a first modification, and FIG. 6B shows a second modification.

  In FIG. 6A, the inductor 60 includes an air core coil 61 and a magnetic wire 20 wound around the air core coil 61. In FIG. 6B, the inductor 70 includes a wrinkle-free core member 70 and a magnetic wire 20 wound around the core member 70. In any of the modifications, by winding the magnetic wire 20 having the annular groove portion 25, it is possible to reduce heat loss and prevent a decrease in inductance.

  In the present embodiment, the magnetic wire 50 has the annular groove portion 55 formed along a direction substantially perpendicular to the longitudinal direction. However, the present invention is not limited to this, and the conductive magnetic layer 52 is not limited to this. As long as it is discontinuously provided in the conducting wire 21 along the longitudinal direction of the magnetic wire 20, it may be a groove portion of any shape. For example, the magnetic wire 50 may have a groove formed on any one of the four surfaces along the longitudinal direction of the conducting wire 51. Thereby, the operation man-hour which forms a groove part can be reduced.

  In this embodiment, after forming the conductive magnetic layer and the insulating layer on the copper wire, the annular grooves are formed at a predetermined interval. However, the present invention is not limited to this, and the conductive magnetic layer is formed on the copper wire. Thereafter, annular grooves may be formed at predetermined intervals on the outer surface of the conductive magnetic layer, and then an insulating layer may be formed. Thereby, the insulation of a magnetic wire can be improved.

  The magnetic wire according to the present embodiment can be used for power system inductors such as a power motor, DC brushless motor, servo motor, air core coil, core coil, toroidal coil, DC / DC converter, DC / AC converter, etc. It can also be used for signal system inductors such as various sensors, resolvers, and power filters.

  According to the present invention, Ni—Zn ferrite, Mn—Zn ferrite, an electromagnetic steel plate, a dust core, or the like can be used as the magnetic material.

DESCRIPTION OF SYMBOLS 1 Inductor 10 Core member 11 Shaft part 12 Eaves part 20 Magnetic wire 21 Conductor 22 Conductive magnetic layer 22a Outer surface 23 Insulating layer 25 Annular groove part

Claims (13)

In a magnetic wire comprising a conducting wire and a conductive magnetic structure formed on the surface of the conducting wire,
The magnetic conductive material according to claim 1, wherein the conductive magnetic material structure has at least one portion that suppresses an eddy current generated in the conductive magnetic material layer from proceeding in a longitudinal direction of the magnetic wire material.   2. The magnetic wire according to claim 1, wherein the conductive magnetic structure is composed of a conductive magnetic layer provided discontinuously along the longitudinal direction of the magnetic wire. Comprising at least one groove formed along a direction substantially perpendicular to the longitudinal direction of the magnetic wire,
The magnetic wire according to claim 2, wherein the conductive magnetic layer is discontinuously provided along the longitudinal direction of the magnetic wire by forming the at least one groove.   4. The magnetic wire according to claim 2, wherein the conductive magnetic layer or the conducting wire has a rough outer surface.   5. The magnetic wire according to claim 4, wherein the maximum height Rz of the outer surface is ½ or more of the maximum thickness of the conductive magnetic layer.   The magnetic member according to claim 1, wherein the conductive magnetic body structure includes a plurality of protrusions formed on a surface of the conducting wire.   2. The magnetic wire according to claim 1, wherein the conductive magnetic body structure is made of a permalloy alloy.   The magnetic wire according to claim 1, further comprising an insulating layer formed on an outer surface of the conductive magnetic structure. In an inductor comprising a core member and a magnetic wire wound around the core member,
The core member includes a shaft portion on which the magnetic wire is wound at a predetermined number of turns,
The magnetic wire comprises a conducting wire and a conductive magnetic layer formed on the surface of the conducting wire,
2. The inductor according to claim 1, wherein the conductive magnetic body structure has at least one portion that suppresses an eddy current generated in the conductive magnetic body layer from proceeding in the longitudinal direction of the magnetic wire.   10. The inductor according to claim 9, wherein the conductive magnetic structure is formed of a conductive magnetic layer provided discontinuously along a longitudinal direction of the magnetic wire. The magnetic wire comprises at least one groove formed along a direction substantially perpendicular to the longitudinal direction of the magnetic wire,
The inductor according to claim 10, wherein the at least one groove portion exists per turn of the winding.   The inductor according to claim 10 or 11, wherein the conductive magnetic layer or the conductive wire has a roughened outer surface.   The inductor according to any one of claims 9 to 12, wherein the core member further includes flange portions provided at both ends of the shaft portion.

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