JP2014090069A - Reactor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reactor that reconciles magnetic saturation and loss improvement.SOLUTION: The reactor includes: a coil 11 of a wound conductor with electrically insulated surfaces; a soft magnetic body 10 mainly containing a metal magnetic powder and a binder; and reluctance parts 21, 22 having a lower magnetic permeability than the soft magnetic body 10. The soft magnetic body 10 encloses at least an inner circumferential surface of the coil 11 and end faces of the coil 11 in winding axis directions parallel to a winding axis, and the reluctance parts 21, 22 extend toward the winding axis from a middle region of the inner circumferential surface of the coil 11 and a neighborhood thereof in the winding axis directions.

Description

  The present invention relates to a reactor that performs voltage conversion using inductance.

  The composite magnetic material slurry in which the liquid thermosetting resin and the metal soft magnetic powder are mixed is poured into a container that accommodates the supported coil, and the composite magnetic material slurry is thermally cured, so that it is several tens of A to several Studies have been made on a reactor configured so that a soft magnetic material is less likely to be magnetically saturated even when a large current of 100 A is applied.

  Further, for example, paragraph 0058 of Patent Document 1 describes a configuration as shown in FIG.

  FIG. 11 is a cross-sectional view showing a reactor of Patent Document 1 which is a conventional technique.

  As shown in FIG. 11, the surface of the coil 11 embedded in the soft magnetic body 10 is covered with an insulator 12, and magnetoresistive portions 21, 22 are provided at the ends in the winding axis direction on the inner peripheral surface of the coil 11. There is a proposal to average the distribution of magnetic flux density by thinning the central portions of the magnetoresistive portions 21 and 22.

JP 2006-4957 A

  The magnetic flux density is averaged by the configuration shown in FIG. 11 described in Patent Document 1 and the inductance is hardly saturated. On the other hand, the magnetic flux Bi in the vicinity of the coil 11 in FIG. , 22, the magnetic flux is directed in the direction to avoid the magnetic flux, so that the magnetic flux enters the inside of the coil 11, so that there is a problem that eddy current loss increases.

  Accordingly, an object of the present invention is to provide a reactor that achieves both magnetic saturation and improved loss.

  To solve the above problems, the present invention provides a coil in which a conductor whose surface is electrically insulated is wound, a soft magnetic body mainly containing metal magnetic powder and a binder, and a magnetic resistance having a lower magnetic permeability than the soft magnetic body. And the soft magnetic body surrounds at least an inner peripheral surface of the coil and an end surface in a winding axis direction parallel to the winding axis of the coil, and the magnetoresistive portion is arranged on the inner side of the coil with respect to the winding axis direction. This is solved by a reactor provided so as to extend from the central portion of the peripheral surface and the vicinity thereof toward the winding shaft.

  In addition, the said center part is the range to 0.5X from the said inner peripheral surface to the winding axis side when the thickness of the radial direction of the said coil is set to X, and follows the winding axis direction of the said coil. It is desirable that the region be in the range of 0.25Y to 0.75Y where Y is the height.

  The magnetoresistive portion is a cone-type magnetoresistive portion whose rotational symmetry axis coincides with the winding axis, and the outer peripheral end of the cone-type magnetoresistive portion is the center of the coil on the inner peripheral surface of the coil. It is desirable to be placed in the department.

  In addition, it is desirable that an angle θ formed between the cone-type magnetoresistive portion and the coil in the radial direction is in a range of 10 ° to 90 °.

  Further, it is preferable that two cone-type magnetoresistive portions are provided, the cone-type magnetoresistive portions have a plane-symmetric shape, and the outer peripheral end portions are close to each other.

  Further, it is desirable to further include a coupling portion that couples the outer peripheral end portions to each other.

  Further, it is desirable that the outer peripheral end portion is in contact with the inner peripheral surface.

  Moreover, it is desirable that a part of the outer peripheral end is separated from the inner peripheral surface.

  According to the present invention, it is possible to provide a reactor in which both magnetic saturation and loss are improved.

It is a perspective view which shows the reactor in Embodiment 1 of this invention. It is sectional drawing which shows the reactor in Embodiment 1 of this invention, and has shown the cross section of the A surface in FIG. It is sectional drawing which shows the reactor in Embodiment 2 of this invention, and has shown the modification of FIG. It is sectional drawing which shows the reactor in Embodiment 3 of this invention, and has shown the modification of FIG. It is sectional drawing which shows the reactor in Embodiment 3 of this invention, and has shown the modification of FIG. It is sectional drawing which shows the reactor in Embodiment 4 of this invention, and has shown the modification of FIG. It is sectional drawing which shows the reactor in Embodiment 5 of this invention, and has shown the modification of FIG. It is sectional drawing in the middle of preparation of the reactor in Embodiment 6 of this invention. FIG. 7 corresponds to the cross section A of FIG. It is the front view seen from the winding axis direction of the coil in the middle of preparation of the reactor in Embodiment 7 of this invention. It is the figure which looked at the magnetoresistive part in Embodiment 7 of this invention from the orthogonal | vertical direction with respect to the rotational symmetry axis. It is sectional drawing which shows the reactor of patent document 1 which is a prior art.

(Embodiment 1)
FIG. 1 is a perspective view showing a reactor in Embodiment 1 of the present invention.

  The reactor of FIG. 1 has a configuration in which cone-shaped magnetoresistive portions 21 and 22 are arranged inside a coil 11, and the whole is buried by a soft magnetic body 10 mainly containing metal magnetic powder and a nonmagnetic binder. It has become. The relative magnetic permeability of the soft magnetic body 10 is preferably 10 or more, preferably 500 or less, and more preferably 100 or less so as not to cause magnetic saturation due to a large current flowing through the coil 11.

  Here, the magnetoresistive portions 21 and 22 may be configured by a magnetic gap such as a cavity or a nonmagnetic material, or may be configured by a soft magnetic material having a lower magnetic permeability than the soft magnetic material 10.

  The coil 11 may be formed by winding a round wire or a flat wire whose surface is insulated and may be formed by winding a conductive foil through an insulating separator.

  Here, in order to make a reactor that conducts a large current of several tens of A to several hundreds of A, it is desirable that the metal magnetic powder has a high saturation magnetic flux density, such as Fe-Si, Fe-Si-Al, and other iron-based ones. It is desirable to be an alloy. The binder is preferably a thermosetting liquid epoxy resin.

  The configuration of FIG. 1 is a composite magnetic material slurry in which a coil 11 is hollowly supported in a container (not shown) and is put together with the magnetoresistive portions 21 and 22, and mixed with a liquid uncured epoxy resin and metal soft magnetic powder. It can be prepared by pouring into a container and thermosetting the composite magnetic material slurry.

  In addition, the soft magnetic body 10 may be comprised with a dust core, and the soft magnetic body 10 may be comprised combining the block of a dust core. In this case, the magnetic resistance units 21 and 22 may be provided in advance in the dust core block that is the core of the coil 11 and assembled around the coil 11.

  FIG. 2 is a cross-sectional view showing the reactor in the first embodiment of the present invention, and shows a cross-section of the A surface in FIG.

  In FIG. 2, the surface of the coil 11 is covered with the insulator 12. However, the structure without the insulator 12 may be used as long as a sufficiently strong insulating film is formed on the surface of the conductor constituting the coil 11.

  The outer peripheral end portions of the cone-type magnetoresistive portions 21 and 22 are both inner peripheral surfaces of the coil 11 and the insulator 12 and are in contact with the central portion with respect to the vertical direction of the paper surface, which is a winding shaft.

  Further, the inner peripheral end portions of the magnetoresistive portions 21 and 22 are directed toward the end portion in the vertical direction of the paper surface, which is a winding axis in the region C surrounded by the inner peripheral surface of the coil 11, and protrude from the region C in FIG. ing.

  Here, the magnetic fluxes Bi and Bo are magnetic fluxes generated by energizing the coil 11.

  Unlike the case of FIG. 11, the magnetic flux Bi in the vicinity of the coil 11 is more suppressed than the case of FIG. 11 even if the magnetic flux is bent so as to avoid the magnetoresistive portions 21 and 22. This is due to the fact that the outer peripheral ends of the magnetoresistive portions 21 and 22 are in the central portion already described.

  Further, since the magnetic flux Bo away from the coil 11 also bends so as to avoid the magnetoresistive portions 21 and 22, the distribution of the magnetic flux can be spread to the end of the soft magnetic body 10 along the winding axis of the coil 11. Since the superposition characteristics are improved and the iron loss is proportional to the square of the magnetic flux density, the uniform magnetic flux density leads to an improvement in the hysteresis loss of the soft magnetic body 10.

  That is, the present invention relates to a coil 11 in which a conductor whose surface is electrically insulated is wound, a soft magnetic body 10 mainly containing metal magnetic powder and a binder, and a magnetic resistance having a magnetic permeability lower than that of the soft magnetic body 10. Portions 21 and 22, the soft magnetic body 10 surrounds at least the inner peripheral surface of the coil 11 and the end surface in the winding axis direction parallel to the winding axis of the coil 11, and the magnetoresistive portions 21 and 22 are the inner periphery of the coil 11. The embodiment of the reactor provided so that it may extend toward the winding axis from the center part with respect to the winding axis direction in the surface and its vicinity can be taken.

(Embodiment 2)
FIG. 3 is a cross-sectional view showing a reactor according to Embodiment 2 of the present invention, and shows a modification of FIG.

  2 differs from FIG. 2 in the first embodiment in that the outer peripheral ends of the magnetoresistive portions 21 and 22 are separated from the surface of the insulator 12 by a distance Xg.

  Here, the radial thickness of the coil 11 is Xw, and the height along the winding axis direction is Yw.

  Further, with reference to one end of the coil 11 in the winding axis direction as a reference, the distance on the winding axis direction end side of the coil 11 on the outer peripheral end of the magnetoresistive portion 21 is Y1, and on the outer end of the magnetoresistive portion 22 The distance on the winding axis direction end side of the coil 11 is Y2.

  In addition, an angle formed by the magnetoresistive portions 21 and 22 and the radial direction of the coil 11 is θ.

  When each parameter is defined in this way, the distance Xg is set to be 0. 0 to improve the DC superposition characteristics by making the magnetic flux density uniform while improving the eddy current loss by preventing the magnetic flux from entering the coil 11. 5Xw or less is desirable, more desirably 0.14Xw or less, distance Y1 is desirably 0.75Yw or less, more desirably 0.61Yw or less, and distance Y2 is desirably 0.25Yw or more. More preferably, it is 39Yw or more, and the formed angle θ is preferably 0 ° or more, more preferably 30 ° or more, further preferably 80 ° or less, and more preferably 70 ° or less. desirable.

  That is, in the present embodiment, the central portion is a range from the top of the inner peripheral surface of the coil 11 to the winding axis side by 0.5Xw when the radial thickness of the coil 11 is Xw, and the coil 11 An embodiment of a reactor that is a region in the range of 0.25 Yw to 0.75 Yw when the height along the winding axis direction of Y is Yw can be taken.

  In the present invention, the magnetoresistive portions 21 and 22 are cone-type magnetoresistive portions 21 and 22 whose rotational symmetry axes coincide with the winding axis of the coil 11, and the outer peripheral ends of the cone-type magnetoresistive portions 21 and 22 are Embodiment of the reactor arrange | positioned in the center part with respect to the winding-axis direction in the internal peripheral surface of the coil 11 can be taken.

  Further, the present invention can take an embodiment of a reactor in which the outer peripheral end portions of the magnetoresistive portions 21 and 22 are in contact with the inner peripheral surface of the coil 11 or the insulator 12.

  Further, the present invention can take an embodiment of a reactor in which the angle θ formed in the radial direction between the cone-type magnetoresistive portions 21 and 22 and the coil 11 is in the range of 0 ° to 80 °.

(Embodiment 3)
FIG. 4 is a cross-sectional view showing a reactor according to Embodiment 3 of the present invention, and shows a modification of FIG.

  2 differs from FIG. 2 in the first embodiment in that the magnetoresistive portion 22 is not provided. Even in such a configuration, similarly to the first embodiment, the magnetic flux Bi in the vicinity of the coil 11 can be prevented from entering the coil 11.

  FIG. 5 is a cross-sectional view showing a reactor according to Embodiment 3 of the present invention, and shows a modification of FIG.

  As in FIG. 3 in the second embodiment, when the thickness Xw, the height Yw, the distance Xg, the distance Y1, Y2, and the angle θ formed are defined, the eddy current loss is improved by preventing the magnetic flux from entering the coil 11. On the other hand, in order to improve the DC superposition characteristics by making the magnetic flux density uniform, the distance Xg is desirably 0.5Xw or less, more desirably 0.14Xw or less, and the distance Y1 is desirably 0.75Yw or less. 61Yw or less is more desirable, the distance Y2 is desirably 0.25Yw or more, more desirably 0.39Yw or more, and the formed angle θ is desirably 0 ° or more, and 30 ° or more. Is more desirably 80 ° or less, and more desirably 70 ° or less.

(Embodiment 4)
FIG. 6 is a cross-sectional view showing a reactor according to Embodiment 4 of the present invention, and shows a modification of FIG.

  2 differs from FIG. 2 in the first embodiment in that the inner peripheral end portions of the magnetoresistive portions 21 and 22 are bent.

  In order to adjust the distribution of the magnetic flux Bo away from the coil 11, the inner peripheral end may be bent as shown in FIG.

  Further, the magnetic flux distribution may be finely adjusted by reducing the thickness of the magnetoresistive portions 21 and 22 toward the inner peripheral end.

(Embodiment 5)
FIG. 7 is a cross-sectional view showing a reactor according to Embodiment 5 of the present invention, and shows a modification of FIG.

  2 is different from FIG. 2 in the first embodiment in that a coupling portion 23 for coupling the inner peripheral ends of the magnetoresistive portions 21 and 22 to each other is provided.

  Since the magnetoresistive portions 21 and 22 can be integrated by the coupling portion 23, it is possible to prevent a positional shift between the magnetoresistive portions 21 and 22 and a shift between the magnetoresistive portions 21 and 22 and the winding axis of the coil 11. .

(Embodiment 6)
FIG. 8 is a cross-sectional view in the middle of creating a reactor according to Embodiment 6 of the present invention. FIG. 7 corresponds to the cross section A of FIG.

  When the uncured soft magnetic body 10 is poured while supporting the coil 11, the insulator 12, and the magnetoresistive portions 21 and 22 in a container not shown, a gap 211 is provided between the magnetoresistive portions 21 and 22 and the insulator 12. 221 is provided, the uncured soft magnetic body 10 is prevented from collecting in the gap between the magnetoresistive portion 21 and the insulator 12 and a cavity remaining between the magnetoresistive portion 22 and the insulator 12. be able to.

(Embodiment 7)
FIG. 9: is the front view seen from the winding-axis direction of the coil in the middle of preparation of the reactor in Embodiment 7 of this invention. FIG. 9 shows a state in which the magnetoresistive portions 21 and 22 and the coil covered with the insulator 12 are assembled before the soft magnetic material is provided. FIG. 9 shows that one of the magnetoresistive portions 21 and 22 can be seen depending on the winding axis direction of the coil.

  Between the magnetoresistive portions 21 and 22 and the insulator 12, there are a portion in which gaps 211 and 221 are provided and a portion in contact with or coupled to each other.

  The cross section of the DD plane in FIG. 9 has a configuration as shown in FIG. 3 after the soft magnetic material is provided, and the cross section of the EE plane has a configuration as shown in FIG.

  FIG. 10 is a view of the magnetoresistive unit according to the seventh embodiment of the present invention viewed from the direction perpendicular to the rotational symmetry axis.

  Since the magnetoresistive portions 21 and 22 are coupled by the coupling portion 23, it is possible to prevent a positional shift between the magnetoresistive portions 21 and 22 and a shift between the magnetoresistive portions 21 and 22 and the winding axis of the coil.

  That is, the present invention includes two cone-type magnetoresistive portions 21 and 22, and the cone-type magnetoresistive portions 21 and 22 are shaped symmetrically to each other and the outer peripheral ends are close to each other. Can take form.

  Further, the present invention can take an embodiment of a reactor that further includes a coupling portion 23 that couples the outer peripheral ends of the two cone-type magnetoresistive portions 21 and 22 to each other.

  Further, the present invention can take an embodiment of a reactor having gaps 211 and 221 in which part of the outer peripheral end portions of the two cone type magnetoresistive portions 21 and 22 are separated from the inner peripheral surface.

DESCRIPTION OF SYMBOLS 10 Soft-magnetic body 11 Coil 12 Insulator 21, 22 Magnetoresistance part 23 Coupling part 211, 221 Gap Bi, Bo Magnetic flux C Area | region Xw Thickness Xg Distance Yw Height Y1, Y2 Distance (theta) The angle

Claims (8)

A coil wound with a conductor whose surface is electrically insulated;
A soft magnetic material mainly containing metal magnetic powder and a binder;
Comprising a magnetoresistive portion having a lower magnetic permeability than the soft magnetic material;
The soft magnetic body surrounds at least the inner peripheral surface of the coil and the end surface in the winding axis direction parallel to the winding axis of the coil,
The reactor, wherein the magnetoresistive portion is provided so as to extend toward the winding shaft from the inner peripheral surface of the coil in the winding axis direction and a central portion in the vicinity thereof. The central portion is
When the thickness in the radial direction of the coil is X, it is in the range of 0.5X from the top of the inner peripheral surface to the winding axis side, and
The reactor according to claim 1, wherein the reactor is a region in a range of 0.25Y to 0.75Y where Y is a height along the winding axis direction of the coil. The magnetoresistive portion is a cone type magnetoresistive portion whose rotational symmetry axis coincides with the winding axis,
3. The reactor according to claim 1, wherein an outer peripheral end portion of the cone-type magnetoresistive portion is arranged at a central portion with respect to a winding axis direction on an inner peripheral surface of the coil.   4. The reactor according to claim 3, wherein an angle θ formed between the cone-type magnetoresistive portion and the coil in a radial direction is in a range of 0 ° to 80 °. With two cone-shaped magnetoresistive sections,
5. The reactor according to claim 3, wherein the cone-shaped magnetoresistive portions have shapes symmetrical to each other and the outer peripheral end portions are close to each other.   The reactor according to claim 5, further comprising a coupling portion that couples the outer peripheral end portions to each other.   The reactor according to any one of claims 3 to 6, wherein the outer peripheral end portion is in contact with the inner peripheral surface.   The reactor according to any one of claims 3 to 7, wherein a part of the outer peripheral end is separated from the inner peripheral surface.

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