JP2016152257A - Inductance element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inductance element capable of being used in a wide frequency band, which sufficiently functions even in a high frequency band exceeding a resonance point between an inductance value of an element and a winding capacitance thereof.SOLUTION: An inductance element is configured such that: a first magnetic core 1 and a second magnetic core 2 are laminated so that central axes thereof overlap to each other thereby to form a composite body; a metal member 4 is disposed to cover a side face of the composite body; and, after the composite body is housed in an insulating case 3, a winding 6 is formed outside the insulating case 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an inductance element mainly used for noise prevention.

  There is a demand for an inductance element applicable to a wide frequency band as a noise prevention choke coil used in electronic equipment, a noise filter for an AC power supply line, and an EMI countermeasure component.

  Patent Document 1 proposes a filter choke for a wide frequency band in which a low-frequency core material and a high-frequency core material, that is, a core material having different impedance characteristics are combined and wound.

  Patent Document 2 proposes a common mode inductance element in which a copper foil having an installation connection terminal is provided in a part of an insulating case that covers the outer peripheral surface of a toroidal magnetic core.

  Patent Document 3 includes a first ferrite core having a through hole and a second ferrite core having a lower permeability than the first ferrite core and having a through hole in a resin casing, For noise countermeasures, the ratio of the axial thickness of the through hole in the first ferrite core to the axial thickness of the through hole in the second ferrite core is in the range of 6: 4 to 9: 1. Composite ferrite cores have been proposed.

JP-A-5-190335 JP 2008-205295 A JP 2014-96538 A

  In the invention described in Patent Document 1, a winding capacity is generated by performing a plurality of windings, and the impedance value of the high-frequency core material is high in a high frequency band above the resonance point between the inductance value of the element and the winding capacity. There is a problem that a frequency band that is damaged and does not function effectively as an inductance element is generated.

  The invention described in Patent Document 2 is provided with a foil-like conductor for capacitively coupling two windings provided for common mode noise removal, and has been devised to increase the impedance in a high frequency band. However, there is a problem that a wide range of frequency bands is not sufficiently handled.

  The invention described in Patent Document 3 proposes a technique for flattening the frequency characteristics of impedance by combining ferrite cores having different magnetic permeability, but is a composite ferrite core used for a noise current absorber, and windings It is not an inductance element that is applied.

  The present invention can be used in a wide range of frequency bands, that is, the impedance characteristics inherent to the magnetic material that constitutes the element even in a high frequency band above the resonance point between the inductance value of the element and the winding capacitance. An object of the present invention is to provide an inductance element that functions effectively without impairing the above.

  Even if an inductance element is configured by combining magnetic cores having different magnetic permeability in order to flatten the frequency characteristics and cover a wide frequency band, for example, the insertion loss value corresponding to the conduction noise regulation frequency band If the winding is applied more than a certain number of times, the winding capacity increases. At frequencies above the resonance point between the inductance value of the element and the winding capacity, the influence of the winding capacity on the impedance characteristics of the element This is because it becomes larger and it is not possible to obtain a sufficient attenuation characteristic as an inductance element.

  That is, by providing a metal member disposed so as to be in contact with at least a part of the magnetic core between the magnetic core and the winding, and a grounding terminal that conducts the metal member, a grounding capacitance is provided between the winding and the metal member. The winding capacitance is canceled by this grounding capacitance.

  Thereby, the winding capacity that impairs the effect of the combination of magnetic cores having different magnetic permeability is reduced, and the above-mentioned problems are solved by expressing the original magnetic characteristics of each of the combined magnetic cores.

  According to the present invention, a metal member that conducts to a ground terminal is disposed on at least a part of a surface of a composite including two or more kinds of magnetic cores having different initial magnetic permeability, and the composite and the metal member are used as cores. An inductance element characterized by being wound is obtained.

  According to the present invention, there is obtained an inductance element in which the two or more types of magnetic cores include a first magnetic core and a second magnetic core having an initial permeability lower than that of the first magnetic core.

  According to the present invention, the first magnetic core has an initial permeability of 5000 or more, preferably 18000 or less, and the second magnetic core has an initial permeability of 2000 or less (not including 0), preferably 120 or more. An inductance element is obtained.

  According to the present invention, it is possible to obtain an inductance element in which each of the first magnetic core and the second magnetic core includes one or more divided bodies.

  According to the present invention, an inductance element is obtained, wherein the volume ratio of the second magnetic core in the composite is smaller than the volume ratio of the first magnetic core.

  According to the present invention, it is possible to obtain an inductance element in which the metal member is arranged so that at least a part thereof is in contact with the second magnetic core.

  According to the present invention, an inductance element characterized in that an elastic member is disposed at least at a part between the first magnetic core and the second magnetic core can be obtained.

  According to the present invention, an inductance element characterized in that the first magnetic core and the second magnetic core are annular bodies, and the windings are formed in a toroidal shape is obtained.

  According to the present invention, a choke coil using the inductance element is obtained.

  According to the present invention, a noise countermeasure component using the inductance element can be obtained.

  INDUSTRIAL APPLICABILITY According to the present invention, an inductance element that can be used in a wide frequency band without any deterioration in attenuation characteristics even in a high frequency band above the resonance point between the inductance value of the element and the winding capacitance, and a choke coil using the inductance element In addition, noise countermeasure parts and EMI countermeasure parts can be provided.

FIG. 1A is a top view, FIG. 1B is a cross-sectional view taken along the line AA ′ of FIG. 1A, and FIG. 1C is a diagram illustrating the inductance element of the present invention. It is sectional drawing in BB 'of). 2A and 2B are diagrams illustrating an inductance element according to the present invention, in which FIG. 2A is a top view, FIG. 2B is a cross-sectional view taken along line AA ′ in FIG. 2A, and FIG. It is sectional drawing in BB 'of). It is a figure explaining the magnetic core in the inductance element of this invention. It is a figure explaining the magnetic core in the inductance element of this invention. It is a figure which shows the relationship between the frequency and insertion loss in the inductance element of this invention. It is a figure which shows the relationship between the frequency and insertion loss in the conventional inductance element.

  The present invention combines a magnetic core having different initial permeability, winds it with a metal member arranged so as to be in contact with at least a part of the magnetic core, and provides a ground terminal that is electrically connected to the metal member. By removing the influence of the capacitance and not impairing the impedance characteristics particularly in the high frequency band, an inductance element is realized that realizes flattening of the frequency characteristics, which is a composite effect of the magnetic core.

  Hereinafter, embodiments of the present invention will be described in detail.

(First embodiment)
1A and 1B are diagrams illustrating an inductance element according to the present invention. FIG. 1A is a top view, FIG. 1B is a cross-sectional view taken along line AA 'in FIG. 1A, and FIG. It is sectional drawing in BB 'of 1 (a).

  A ring-shaped first magnetic core 1 and second magnetic core 2 are laminated so that their central axes overlap to form a composite, and a metal member 4 made of a copper plate is disposed so as to cover the side surface of the composite, thereby insulating case 3 Then, the winding 6 is formed outside the insulating case 3 to constitute the inductance element 100.

  The first magnetic core 1 has an initial permeability of 10,000, and is made of a Mn—Zn ferrite material having an outer diameter of 19 mm, an inner diameter of 11 mm, and a height of 5 mm. The second magnetic core 2 has an initial permeability of 700 and is the same as the first magnetic core. It consists of a shaped Ni-Zn ferrite material.

  The metal member 4 has a length of 60 mm, a width of 7 mm, and an L-shaped projecting portion having a width of 2 mm from the center. Form.

  The winding 6 is formed by preparing two types of polyurethane-coated copper wires having a wire diameter of 0.8 mm and winding them 21 turns so that the winding directions are symmetric, and used as a common mode choke coil.

  In the present embodiment, the case where two types of magnetic cores are combined has been exemplified, but two or more types may be used, and a material made of a magnetic material whose permeability does not disappear in a desired frequency band is appropriately selected and combined. Just do it.

  Considering mass productivity and application, the first magnetic core has a magnetic permeability of a certain value or more in at least a low frequency band, that is, a magnetic core having an initial permeability of 5000 to 18000 is used as the second magnetic core. In addition, it is preferable to select and combine at least two kinds of magnetic cores having a magnetic permeability of a certain value or higher in the high frequency band, that is, a magnetic core having an initial magnetic permeability of 120 to 2000.

  Further, considering the correspondence to the conduction noise regulation band of 150 KHz to 30 MHz, the first magnetic core uses a core having an initial permeability of 10000 to 15000 and the second magnetic core uses a core having an initial permeability of 500 to 1000. Is more preferable.

  A magnetic core made of any material may be used as long as the above conditions are satisfied, but a magnetic core made of Mn—Zn ferrite material is used as the first magnetic core and has a lower magnetic permeability than the first magnetic core. It is preferable to select at least two kinds of magnetic cores made of Ni—Zn ferrite material as the second magnetic core.

  The shape of the composite composed of the magnetic core is preferably an annular shape, that is, a closed magnetic path toroidal shape that forms a closed magnetic circuit and can sufficiently secure a region around which the coil is wound. Either is acceptable. Moreover, the shape which comprises a closed magnetic circuit does not necessarily need to be.

  Further, the magnetic core may be configured by combining one or more divided bodies, for example, for the convenience of adjusting the manufacturing process or the magnetic characteristics.

  The metal member disposed so as to be in contact with at least a part of the magnetic core may be any metal member as long as it has conductivity, but copper foil is preferable in consideration of mass productivity and conductivity.

  The metal member may be in any form that can come into contact with a magnetic core such as a plate, foil, or line, and any shape that can sufficiently ensure contact with the magnetic core such as a rectangle, circle, or strip. But you can.

  The metal member may be arranged on any of the side peripheral surface, top surface, bottom surface, and the like of the magnetic core in accordance with the drawing position of the ground terminal.

  The ground terminal may be in any form as long as it is electrically connected to the metal member. That is, it may be formed by connecting another member to the metal member, or may be formed by extending or bending a part of the metal member as exemplified in the present embodiment.

  The winding is preferably applied to the composite of the magnetic core via an insulating member such as an insulating tape or a resin coating film as necessary, and as exemplified in the present embodiment, considering mass productivity. It is more preferable to use an insulating case.

  As illustrated in the present embodiment, for example, two coated copper wires are wound so that the winding directions are symmetrical, and a single coated copper wire is wound as a common mode choke coil. It may be turned to a normal mode choke coil.

(Second Embodiment)
2A and 2B are diagrams for explaining the inductance element of the present invention. FIG. 2A is a top view, FIG. 2B is a cross-sectional view taken along line AA 'in FIG. 2A, and FIG. It is sectional drawing in BB 'of 2 (a).

  A ring-shaped first magnetic core 1 and second magnetic core 2 are laminated so that their central axes overlap to form a composite, and a metal member 4 made of a copper plate is disposed so as to cover the side surface of the composite, thereby insulating case 3 Then, the winding 6 is formed outside the insulating case 3 to constitute the inductance element 200.

  The first magnetic core 1 is made of a Mn—Zn ferrite material having an outer diameter of 19 mm, an inner diameter of 11 mm, and a height of 7 mm, and the second magnetic core 2 is made of a Ni—Zn ferrite material having an outer diameter of 19 mm, an inner diameter of 11 mm, and a height of 3 mm. Become.

  That is, by making the thickness of the second magnetic core thinner than that of the first magnetic core, the volume ratio of the second magnetic core having a lower initial permeability than that of the first magnetic core is reduced.

  The insertion loss in a so-called low frequency band mainly depends on the impedance value of the first magnetic core having a high initial permeability. On the other hand, in the high frequency band, the impedance value of the first magnetic core starts to attenuate, but if the influence of the winding capacitance is removed, the impedance value of the second magnetic core having an initial permeability lower than that of the first magnetic core. As a result, the insertion loss of the entire device increases.

  Therefore, in order to flatten the frequency characteristics in a wide frequency band, the volume ratio of the second magnetic core is decreased as described above, that is, the volume ratio of the first magnetic core is increased, so that the frequency characteristic in the low frequency band is increased. It is preferable to ensure a sufficient impedance value.

  In the present embodiment, the volume ratio of the second magnetic core is approximately half the volume ratio of the first magnetic core, but the volume ratio of the magnetic core to be combined causes a desired impedance value to be expressed in a desired frequency band. Any volume ratio can be used. According to the experiment, the volume ratio of the first magnetic core to the volume ratio of the second magnetic core is preferably 6: 4 to 8: 2, and more preferably 7: 3.

  For example, if the magnetic core has an annular shape with the same inner diameter and outer diameter, the thickness is changed. If the magnetic core has an annular shape with the same thickness, the inner diameter and the outer diameter are changed. It is preferable from the viewpoint of mass productivity and shape stability of the final product to adjust the volume ratio.

(Third embodiment)
FIG. 3 is a view for explaining a magnetic core in the inductance element of the present invention.

  The first magnetic core 1 and the second magnetic core 2 having an annular shape are arranged concentrically so that the first magnetic core 1 is on the inner side to form a composite, and the second magnetic core 2 that is a side surface of the composite is formed. A metal member 4 made of a copper plate is disposed so as to cover the core, and a winding 6 is provided. A ground terminal 5 is connected to the metal member 4.

  In addition, since the coil | winding 6 is formed in the outer side of an insulation case, after accommodating in the insulation case which is not shown in figure, it has shown with the dotted line.

  The first magnetic core 1 is made of a Mn—Zn ferrite material having an outer diameter of 15 mm, an inner diameter of 11 mm, and a height of 10 mm. The second magnetic core 2 is made of an Ni—Zn ferrite material having an outer diameter of 19 mm, an inner diameter of 15.1 mm, and a height of 10 mm. Become.

  When combining magnetic cores, as exemplified in the first or second embodiment and the present embodiment, for example, in the case of an annular shape, a plurality of magnetic cores having the same inner diameter and outer diameter are laminated. Select from any shape, arrangement, and method, such as combining multiple magnetic cores in concentric circles with different diameters, hollowing out part of the magnetic core, and embedding one or more magnetic cores having different initial permeability. However, in consideration of mass productivity, it is more preferable to laminate in the axial direction or the radial direction. Similarly, in the case of a magnetic core having a shape other than an annular shape, it may be appropriately selected from any shape, arrangement, and method.

  As exemplified in the present embodiment, a magnetic core made of, for example, Mn—Zn ferrite material having conductivity is used as the first magnetic core, and a magnetic material made of, for example, Ni—Zn ferrite material having insulating properties as the second magnetic core. When the core is used, it is preferable to arrange the metal member in contact with at least a part of the second magnetic core in order to reduce the capacitance generated between the metal member and the first magnetic core.

  Further, the metal member is prevented from being corroded due to the potential difference caused by the contact between the metal member and the first magnetic core, and the distance between the metal member and the first magnetic core can be maintained sufficiently. The member is preferably arranged so as to be in contact with at least a part of the second magnetic core.

(Fourth embodiment)
FIG. 4 is a diagram illustrating a magnetic core in the inductance element of the present invention.

  The first magnetic core 1 and the second magnetic core 2 having an annular shape are laminated in the axial direction so that the central axes overlap with each other via the elastic member 7 to form a composite, and the second magnetic core 2 serving as the bottom surface of the composite is formed. A metal member 4 made of a copper plate having an annular shape so as to cover the wire is used as a core to which the winding 6 is applied. A ground terminal 5 is connected to the metal member 4.

  In addition, since the coil | winding 6 is formed in the outer side of an insulation case, after accommodating in the insulation case which is not shown in figure, it has shown with the dotted line.

  The first magnetic core 1 is made of a Mn—Zn ferrite material having an outer diameter of 19 mm, an inner diameter of 11 mm, and a height of 7 mm, and the second magnetic core 2 is made of a Ni—Zn ferrite material having an outer diameter of 19 mm, an inner diameter of 11 mm, and a height of 2 mm.

  In the composite of the magnetic cores, in order to prevent the breakage of the magnetic cores due to the generation of stress due to the contact or warpage of the magnetic cores, as exemplified in this embodiment, the first magnetic core and the second magnetic core It is preferable to arrange an elastic member in at least a part between the two.

  The elastic member is preferably in the form of a sheet, and for example, it is preferable to use the same material as PET film, silicone rubber, and insulating case. In consideration of mass production, it is particularly preferable to provide a partition portion in the insulating case in advance.

  FIG. 5 is a diagram showing the relationship between frequency and insertion loss in the inductance element of the present invention. The horizontal axis represents frequency (MHz) and the vertical axis represents insertion loss (dB).

  FIG. 6 is a graph showing the relationship between frequency and insertion loss in a conventional inductance element. The horizontal axis represents frequency (MHz) and the vertical axis represents insertion loss (dB).

  Using the inductance element exemplified in the first embodiment as the inductance element of the present invention, the insertion loss at each frequency was measured. The result is shown in FIG.

  According to FIG. 5, the inductance element of the present invention maintains an insertion loss of 30 dB or more at a frequency of 100 kHz to 1 MHz, an insertion loss of 40 dB or more at a frequency of 1 to 30 MHz, and has a high impedance value even in a high frequency band. It is shown that.

  Further, in recent years, particularly, the demand for noise countermeasures has increased, and an insertion loss of 40 dB or higher is exhibited even in a high frequency band of 10 KHz or higher where a high insertion loss value is required even in a low frequency band, and the frequency is 20 MHz to 30 MHz. It shows that it has a high impedance value with an insertion loss of 50 dB or more.

  From the above measurement results, the inductance element of the present invention exhibits the original impedance characteristics of the magnetic core without being affected by the winding capacitance by providing the metal member having the ground terminal and removing the winding capacitance. You can see that

  As a conventional inductance element, an inductance element having a configuration excluding the metal member and the ground terminal from the configuration of the inductance element exemplified in the first embodiment was prepared, and the insertion loss at each frequency was measured. The result is shown in FIG.

  According to FIG. 6, the conventional inductance element maintains an insertion loss of 30 dB or more at a frequency of 100 KHz to 1 MHz, and has a high impedance value of an insertion loss of 40 dB or more at a frequency of 1 to 10 MHz.

  However, compared to the low frequency band, the insertion loss is rapidly reduced to 40 dB or less in a high frequency band of 10 MHz or higher that requires equivalent insertion loss or higher depending on the equipment depending on the conduction noise regulation. It has become.

  This is presumed that the impedance value in the high frequency band is reduced due to the influence of the winding capacity.

  That is, in the conventional inductance element, for example, it is necessary to combine other inductance elements having different characteristics, or to supplement other parts such as a capacitor. However, in the inductance element of the present invention, this is not necessary.

  As described above, it can be used in a wide range of frequency bands, that is, the impedance characteristics do not deteriorate even in a high frequency band above the resonance point between the inductance value of the element and the winding capacitance, and it has a good attenuation characteristic An inductance element, a choke coil suitable for noise prevention using the inductance element, a noise countermeasure component for an AC power supply line, and an EMI countermeasure component can be obtained.

  As mentioned above, although the Example of this invention was described, this invention is not limited above, The change and correction of a structure are possible in the range which does not deviate from the summary of this invention.

DESCRIPTION OF SYMBOLS 1 1st magnetic core 2 2nd magnetic core 3 Insulation case 4 Metal member 5 Grounding terminal 6 Winding 7 Elastic member 100,200 Inductance element

Claims (10)

  A metal member that is electrically connected to a ground conductor is disposed on at least a part of the surface of a composite including two or more kinds of magnetic cores having different initial magnetic permeability, and winding is performed using the composite and the metal member as a core. An inductance element characterized by that.   2. The inductance element according to claim 1, wherein the two or more magnetic cores include a first magnetic core and a second magnetic core having an initial permeability lower than that of the first magnetic core.   3. The inductance element according to claim 1, wherein the first magnetic core has an initial permeability of 5000 or more, and the second magnetic core has an initial permeability of 2000 or less (not including 0).   4. The inductance element according to claim 1, wherein each of the first magnetic core and the second magnetic core includes one or more divided bodies. 5.   5. The inductance element according to claim 1, wherein a volume ratio of the second magnetic core in the composite is smaller than a volume ratio of the first magnetic core. 6.   The inductance element according to any one of claims 1 to 5, wherein the metal member is disposed so that at least a part thereof is in contact with the second magnetic core.   The inductance element according to any one of claims 1 to 6, wherein an elastic member is disposed at least partly between the first magnetic core and the second magnetic core.   The inductance element according to any one of claims 1 to 7, wherein the first magnetic core and the second magnetic core are annular bodies, and the windings are formed in a toroidal shape.   A choke coil using the inductance element according to claim 1.   A noise countermeasure component using the inductance element according to any one of claims 1 to 8.

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