JP2015060929A - Coil component and power supply device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coil component which has an inductance value changing according to the magnitude of a load current (a DC superimposed current) and is suitable for simplification of the manufacturing and downsizing, and to provide a power supply device using the coil component.SOLUTION: A coil component 100 includes: a ring shaped first magnetic core forming a closed magnetic circuit; and a coil 2 which is wound around the first magnetic core in a spiral manner. The coil component 100 includes a second magnetic core 3, which has the magnetic permeability lower than that of the first magnetic core and forms a closed magnetic circuit, at the inner side of the coil. It is preferable to dispose the second magnetic core between an outer peripheral surface of the first magnetic core and the coil.

Description

  The present invention relates to a coil component such as a reactor or a choke used in various power supply devices, electronic devices, and the like.

  An inductance element such as a choke coil is used in a PFC circuit or a smoothing circuit of a power supply device mounted on a household electric appliance such as an air conditioner, a motor-driven vehicle such as a hybrid vehicle or an electric vehicle, or a solar power generation device. The appropriate inductance value of the inductance element for the power supply device varies depending on the specifications such as the output rating of the circuit and the state of the load. Therefore, in order to configure an efficient power supply device over a wide range from a small current to a large current while taking into account power conversion efficiency, load fluctuation response characteristics, etc., a non-linearity in which the inductance value changes according to the magnitude of the load current An inductance element is used.

  For example, Patent Document 1 proposes the following configuration as a cored coil that changes the inductance non-linearly so as to increase the small current and decrease the large current in order to improve the efficiency particularly at the small current. ing. That is, a plurality of core members formed of magnetic materials having different magnetic permeability are joined to each other, a core having a plurality of annular magnetic paths having different magnetic resistances and no gaps, and the plurality of magnets with respect to the core. It is a coil component provided with the winding wound around the path in common.

JP 2007-73903 A

  Patent Document 1 proposes a coil component whose inductance changes nonlinearly with respect to a load current. However, magnetic materials having different magnetic permeability have a gapless closed magnetic circuit structure, and are joined in the same shape to form a coil component, so that the core member becomes large. For example, even if it is sufficient to ensure a small inductance, a closed magnetic circuit core must be used. In addition, the degree of freedom of shape and the degree of freedom of joining and arrangement are low. Therefore, it is disadvantageous for the simplification and miniaturization of the manufacture of coil components whose inductance changes nonlinearly.

  Accordingly, in view of the above-described problems, the present invention provides a coil component suitable for simplification and miniaturization of a coil component whose inductance value changes according to the magnitude of the load current, and a power supply device using the same. For the purpose.

The coil component of the present invention is a coil component having a ring-shaped first magnetic core constituting a closed magnetic path, and a coil spirally wound around the first magnetic core,
The coil has a second magnetic core having a permeability lower than that of the first magnetic core and constituting an open magnetic path inside the coil.

  In the coil component, it is preferable that the second magnetic core is disposed between an outer peripheral surface of the ring-shaped first magnetic core and the coil.

  Furthermore, in the coil component, it is preferable that the first magnetic core is an amorphous cut core and the second magnetic core is a dust core.

  Moreover, the power supply device of the present invention is characterized by using the coil component.

  According to the present invention, it is possible to provide a swing type coil component that can be miniaturized with a simple structure and a power supply device using the same.

1 shows an embodiment of a coil component according to the present invention. It is a figure which shows other embodiment of the coil components which concern on this invention.

    Hereinafter, although embodiment of the coil component which concerns on this invention is described concretely using figures, this invention is not limited to this. Moreover, the structure demonstrated in each embodiment is applicable also in other embodiment, unless the meaning of other embodiment is impaired, In that case, the overlapping description is abbreviate | omitted suitably.

  FIG. 1 is a view showing an embodiment of a coil component of the present invention. 1A is a view of the coil component as viewed from the direction of the winding axis of the il, and FIG. 1B is a cross-sectional view taken along the line A-A ′ of FIG. A coil component 100 shown in FIG. 1 is a coil component having a ring-shaped first magnetic core 1 constituting a closed magnetic circuit and a coil 2 wound spirally around the first magnetic core 1. The coil component 100 has a second magnetic core 3 having a permeability lower than that of the first magnetic core 1 and constituting an open magnetic path inside the coil 2. Such a structure is a characteristic structure of the coil component 100 shown in FIG.

  In the coil component 100 shown in FIG. 1, a composite magnetic core composed of a plurality of types of magnetic cores is used. The first magnetic core 1 constitutes a closed magnetic circuit, and can exhibit high inductance in a region where the DC superimposed current is small. On the other hand, the second magnetic core 3 has a lower magnetic permeability than the first magnetic core 1 and constitutes an open magnetic circuit. Therefore, although the inductance is lower than that of the first magnetic core 1, the DC superimposed current is large. Inductance can be maintained without saturation to the region.

  Here, in order to secure the inductance in the high DC superimposed current region, if an attempt is made to employ a magnetic core having a closed magnetic circuit structure as in Patent Document 1, the structure of the magnetic core becomes complicated and the entire coil component becomes larger. End up. On the other hand, since the open magnetic circuit structure can be configured with a simple and small magnetic core, the coil component can be simplified and miniaturized. In the embodiment shown in FIG. 1, the first magnetic core 1 has a racetrack shape, and the second magnetic core 3 has a rectangular parallelepiped shape. Since a simple structure in which the second magnetic core 3 is juxtaposed on the racetrack-shaped straight portion of the first magnetic core 1 is employed, the assembly of the composite magnetic core becomes extremely easy.

  The configuration of the composite magnetic core will be further described in detail. In the embodiment shown in FIG. 1, two U-shaped cores are brought into contact with each other via a magnetic gap 4 to constitute a first magnetic core 1. Although the 1st magnetic core 1 can also be comprised with an integral toroidal core, as shown in FIG. 1, assembly of a coil component becomes easy by using a split type core. Although it is possible to directly abut the two U-shaped cores without using a magnetic gap, the effective permeability can be adjusted by providing a magnetic gap. In addition, as shown in FIG. 1, the structure which has a magnetic gap between magnetic cores is also handled as what comprises a closed magnetic circuit.

  The second magnetic core constituting the open magnetic path is not necessarily limited to a rectangular parallelepiped shape. If the second magnetic core is formed into a rod shape, the production of the second magnetic core itself becomes easy. Further, the ring-shaped first magnetic core is not limited to the racetrack shape. For example, a ring-shaped magnetic core having a circular or square outer shape can be used. However, if the first magnetic core has a shape having a straight line portion like a racetrack shape and the second magnetic core has a rectangular parallelepiped shape, the planes can be opposed to each other, so that the space loss Less. Further, from the viewpoint of reducing the space loss, the cross-sectional shape of the second magnetic core 3 as viewed from the winding axis direction (z direction) of the coil is the facing direction of the first magnetic core 1 and the second magnetic core 3 (y It is preferable that the dimension of (direction) is a rectangle smaller than the dimension of the direction (x direction) perpendicular | vertical to it.

  The type of the first magnetic core is not limited to this, but the embodiment shown in FIG. 1 uses an amorphous cut core. The amorphous cut core has characteristics of high saturation magnetic flux density, high magnetic permeability, and low loss, and therefore is suitable for obtaining a high inductance in a low DC superimposed current region. The first magnetic core 1 shown in FIG. 1 is configured by winding an amorphous ribbon with the x direction as the winding axis direction. The material of the amorphous ribbon is not particularly limited. For example, an Fe-based amorphous material may be used. As the magnetic core using the amorphous ribbon, a laminated magnetic core configured by stacking amorphous ribbons punched into a predetermined shape can be used.

  On the other hand, in the embodiment shown in FIG. 1, a dust core is used as the second magnetic core 3. The type of the second magnetic core having a lower permeability than the first magnetic core is not particularly limited. However, since the dust core has a higher inductance than ferrite in the high superimposed current region, the second magnetic core As preferred. The material of the dust core is not particularly limited. For example, Fe-Si based magnetic powder, Fe-Si-Al based magnetic powder, amorphous magnetic powder, etc. can be used as the magnetic powder constituting the dust core.

Although the second magnetic core 3 is disposed adjacent to the first magnetic core 1, the second magnetic core 3 has a lower magnetic permeability than the first magnetic core 1, and thus the first magnetic core 1 to the second magnetic core 1. The flow of magnetic flux to 3 is suppressed. Therefore, even when an amorphous cut core having the configuration shown in FIG. 1 is used as the first magnetic core 1, an increase in core loss can be suppressed.
From the viewpoint of miniaturization, it is preferable that the first magnetic core 1 and the second magnetic core 3 are brought into close contact with each other. On the other hand, from the viewpoint of suppressing the flow of magnetic flux from the first magnetic core to the second magnetic core, the first magnetic core and the second magnetic core can be spaced apart by interposing a spacer member or the like. In this case, the effect of the leakage magnetic flux in the magnetic gap 4 can be further suppressed by making the separation distance between the first magnetic core and the second magnetic core larger than the magnetic gap 4.

  The coil may be configured by winding a composite magnetic core composed of a first magnetic core and a second magnetic core via an insulating sheet or the like, but by using a configuration wound on a bobbin, it is easy to assemble coil components. become. Moreover, the structure of the conducting wire which comprises a coil does not specifically limit this, For example, a round wire, a flat wire, etc. can be used.

  Next, the arrangement of the coil, the first magnetic core, and the second magnetic core will be described. In the embodiment shown in FIG. 1, the coil 3 is spirally wound around one of the two straight portions of the racetrack shape, but can be wound around both of the two straight portions. Further, as long as the second magnetic core is disposed inside the coil and contributes to the improvement of the inductance, the length of the coil in the winding axis direction (z direction) is not limited to this, but as shown in FIG. It is more preferable that the dimensions and arrangement be such that they protrude from both ends of the coil. On the other hand, from the viewpoint of miniaturization of the coil component, it is preferable that the second magnetic core 3 does not protrude from the first magnetic core 1 in the coil winding axis direction.

  In the embodiment shown in FIG. 1, the second magnetic core 3 is disposed between the outer peripheral surface of the ring-shaped first magnetic core 1 and the coil 2 in the y direction. This is to suppress an increase in the dimension of the coil component in the x direction. However, the arrangement of the first magnetic core and the second magnetic core is not limited to this. FIG. 2 shows another embodiment in which the arrangement of the first magnetic core and the second magnetic core is different from the embodiment shown in FIG. The second magnetic core 7 is disposed between the first magnetic core 5 and the coil 6 in a direction (x direction) perpendicular to the outer peripheral surface of the ring-shaped first magnetic core 5. According to such a configuration, it is possible to suppress an increase in the dimension in the y direction of the coil component. Further, even if leakage magnetic flux from a magnetic gap 8 (not shown) adjacent to the second magnetic core 7 flows to the second magnetic core 7, the leakage magnetic flux flows parallel to the surface of the amorphous ribbon. The configuration shown in 2 also contributes to suppression of core loss.

  The first magnetic core and the second magnetic core may be fixed with an adhesive or may be fixed with a band. In the embodiment shown in FIGS. 1 and 2, the number of the second magnetic core is one, but a plurality of the second magnetic cores may be arranged, or a magnetic core having a different permeability is additionally arranged. Is also possible.

  The coil component according to the present invention can be used as a choke or the like to constitute a power supply device such as a home appliance such as an air conditioner, a power conditioner of a solar power generation system, a converter of a hybrid vehicle or an electric vehicle.

  An amorphous cut core (AMCC-6.3 manufactured by Hitachi Metals) is used as the first magnetic core, and an Fe-Si-Al-based powder magnetic core (10 mm × 16 mm × 34 mm) is used as the second magnetic core. A coil component (Example) was constructed. The coil had 26 turns, and the longitudinal direction of the dust core was the coil winding axis direction. The magnetic gap of the amorphous cut core was 0.038 mm. For comparison, a coil component (comparative example) in which the dust core was not disposed in the coil was also produced.

  In the coil part of the comparative example configured only by the amorphous cut core without arranging the dust core, the inductances obtained when the DC superimposed currents Idc = 2A and 30A were 876 μH and 14.6 μH, respectively. On the other hand, in the coil component of the embodiment configured using the first magnetic core (amorphous cut core) and the second magnetic core (Fe-Si-Al-based dust core), the DC superimposed current Idc = 2A. , 30A, the inductances obtained were 900 μH and 42.5 μH, respectively, and a high inductance was obtained. In particular, when the DC superimposed current Idc = 30 A, a higher inductance was obtained compared to the coil component of the comparative example, and it was confirmed that the configuration of the example was particularly effective in the region of the high DC superimposed current.

1: First magnetic core 2: Coil 3: Second magnetic core 4: Magnetic gap 5: First magnetic core 6: Coil 7: Second magnetic core 8: Magnetic gap 100: Coil component 200: Coil component

Claims (4)

A coil component having a ring-shaped first magnetic core constituting a closed magnetic path, and a coil spirally wound around the first magnetic core,
A coil component comprising a second magnetic core having a permeability lower than that of the first magnetic core and constituting an open magnetic path inside the coil.   The coil component according to claim 1, wherein the second magnetic core is disposed between an outer peripheral surface of the ring-shaped first magnetic core and the coil.   The coil component according to claim 1 or 2, wherein the first magnetic core is an amorphous cut core, and the second magnetic core is a dust core.   The power supply device using the coil component as described in any one of Claims 1-3.

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