JP2014022627A - Choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a choke coil having high mass productivity and stable characteristics.SOLUTION: This choke coil includes a soft magnetic core having two closed magnetic path parts 11, 12 and coupling parts 20, 21, two coils 31, 32, and a conductive annular member 4. The coils 31, 32 are wound around the closed magnetic path parts 11, 12 respectively, one closed magnetic path part 11 is coupled to the other adjacent closed magnetic path part 12 by the coupling parts 20, 21, one closed magnetic path part 11, the other closed magnetic path part 12, and the coupling parts 20, 21 are integrally molded, and the conductive annular member 4 is installed so as to enclose the coupling part 20 in the choke coil.

Description

  The present invention relates to a choke coil in which a coil is wound around a soft magnetic core.

  When there are a plurality of inductors constituting the line filter, the inductors cause magnetic interference with each other, thereby degrading the noise removal characteristics of the line filter.

  Patent Document 1 discloses a technique of magnetically separating by providing a shielding member made of metal between adjacent inductors.

JP 2006-186620 A

  However, in order to provide the shielding member between the inductors as in Patent Document 1, a step of bonding between the shielding member and the inductor using an adhesive or the like is required, and extra steps such as time for curing the adhesive are required. There is a problem that the mass productivity is lowered because it takes time.

  Furthermore, if the shield member is bonded to the inductor, the curing stress of the adhesive may act on the soft magnetic core of the inductor. In this case, the inductance varies, and the characteristics of the inductor used as a choke coil decrease. There is a problem that becomes unstable.

  Accordingly, an object of the present invention is to provide a choke coil having high productivity and stable characteristics.

  The present invention includes a soft magnetic core having at least two closed magnetic path portions and at least one coupling portion, at least two coils, and at least one conductive annular member, and the coils are wound around the closed magnetic path portions, respectively. The one closed magnetic path portion and the other adjacent closed magnetic path portion are coupled by a coupling portion, and the one closed magnetic path portion, the other closed magnetic path portion, and the coupling portion are integrally molded and are electrically conductive so as to circulate around the coupling portion. The above-mentioned problem is solved by a choke coil in which a conductive annular member is installed.

  Further, a choke coil in which coupling portions are arranged at both end portions in the magnetic flux direction in the closed magnetic path portion near the region in the region between the adjacent closed magnetic path portions may be used. Here, the magnetic flux direction in the closed magnetic path portion is the direction of the magnetic flux induced in the closed magnetic path portion by energization of the coil.

  Alternatively, the choke coil may include a plurality of coupling portions that couple the closed magnetic path portions to each other, and a conductive annular member may be provided so as to go around all of the coupling portions.

  In addition, a plurality of conductive annular members are conductively connected to each other by a plate-like conductor to form a conductive annular member combination, and the plate-like conductor is a choke coil provided so as to block between the closed magnetic circuit portions. There may be.

  The coils adjacent to each other may be choke coils whose winding axes are orthogonal to each other.

  According to the present invention, it is possible to provide a choke coil having high mass productivity and stable characteristics.

It is a top view which shows 1st Embodiment in this invention. It is sectional drawing which shows 1st Embodiment in this invention, and has shown sectional drawing of the AA surface in FIG. It is a top view which shows 2nd Embodiment in this invention. It is an equivalent circuit diagram showing a second embodiment of the present invention. It is a top view which shows the 3rd Embodiment in this invention. It is sectional drawing which shows 3rd Embodiment in this invention, and has shown sectional drawing of the BB surface in FIG. It is a top view which shows 4th Embodiment in this invention.

  An example of an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a plan view showing a first embodiment of the present invention.

  In FIG. 1, a soft magnetic core having two closed magnetic path portions 11 and 12 and coupling portions 20 and 21, two coils 31 and 32, and a conductive annular member 4 are provided. Coils 31 and 32 are wound, and one closed magnetic path section 11 and the other adjacent closed magnetic path section 12 are coupled by coupling sections 20 and 21, and one closed magnetic path section 11, the other closed magnetic path section 12, The coupling portions 20 and 21 are integrally molded to constitute a choke coil in which the conductive annular member 4 is installed so as to go around the coupling portion 20. Here, the conductive annular member 4 is a member in which a conductor such as metal is formed in an annular shape, such as a short ring used in a transformer or the like.

  FIG. 2 is a cross-sectional view showing the first embodiment of the present invention, and shows a cross-sectional view of the AA plane in FIG.

  The conductive annular member 4 is configured to go around the coupling portion 20.

  The conductive annular member 4 may be configured by electrically connecting both ends of a conductor wire by soldering, screwing, or the like, or a conductor film may be directly formed on the surface of the coupling portion 20 by plating.

  The configuration of the present embodiment shown in FIGS. 1 and 2 is different from the configuration in Patent Document 1, and the closed magnetic path portions 11 and 12 and the coupling portions 20 and 21 are integrally molded as a soft magnetic core. That is, when the soft magnetic core is molded, the plurality of closed magnetic path portions 11 and 12 are already coupled via the coupling portions 20 and 21.

  Therefore, in this embodiment, the process of combining the closed magnetic path portion with the shielding member for realizing the configuration of Patent Document 1 is not necessary.

  In this embodiment, the coupling portions 20 and 21 are configured as a part of the soft magnetic core. However, by installing the conductive annular member 4 so as to circulate around the coupling portion 20, the coupling portion 20 and 21 can be magnetically separated. Therefore, magnetic interference does not occur between the adjacent closed magnetic path portions 11 and 12.

  That is, in the configuration of FIG. 1, the two coupling portions 20 and 21 appear to form a magnetic path that couples the coil 31 and the coil 32, but the conductive ring installed in the coupling portion 20. The magnetic path connecting the coil 31 and the coil 32 is cut off by the member 4.

  Further, in order to ensure magnetic separation, it is desirable that the electrical resistance of the conductive annular member 4 is as low as possible. When the conductive annular member 4 is constituted by a conductor wire, the wire diameter is the connecting portion. In consideration of workability at the time of winding around 20, it is desirable to be 0.1 mm or more and 1.0 mm or less. Furthermore, it is desirable to provide up to five conductive annular members 4 in the coupling portion 20.

  The conductive annular member 4 and the coupling portion 20 may or may not be in contact with each other, or may be joined.

  Here, in FIG. 1, since the coupling portions 20 and 21 are provided in the winding axis direction of the coils 31 and 32, that is, at both ends in the longitudinal direction in the region 5 between the closed magnetic path portion 11 and the closed magnetic path portion 12. Even when a torsional stress is applied to the entire magnetic core, the closed magnetic path portions 11 and 12 are firmly coupled by the two coupling portions 20 and 21, so that the strength of the entire soft magnetic core is ensured. .

  In the present embodiment, the case of the two coils 31 and 32 has been described. However, the number of coils is not limited to two, and for three or more coils, a coupling portion and a conductive annular member are provided between adjacent coils. By adopting the configuration, the magnetic separation between the coils can be performed as in the present embodiment.

(Second Embodiment)
FIG. 3 is a plan view showing a second embodiment of the present invention.

  The first embodiment is different from the first embodiment in that the coil 31 is divided into the coil 311 and the coil 312, the coil 32 is divided into the coil 321 and the coil 322, and the conductive annular member 41 is also installed in the coupling portion 21.

  Since the conductive annular members 4 and 41 are installed in all the coupling parts 20 and 21, the closed magnetic path part 11 and the closed magnetic path part 12 are more reliably magnetically separated.

  The coil 311 and the coil 312 in the choke coil of FIG. 3, the number of turns of the coil 321 and the coil 322 are equal to each other, and the directions of the magnetic flux generated by energizing the coil are opposite to each other. 321 and the coil 322 can constitute an independent common mode choke coil as circuit components.

  FIG. 4 is an equivalent circuit diagram showing a second embodiment of the present invention.

  FIG. 4 shows a configuration of a noise filter in which the choke coil of FIG. 3 is configured as a common mode choke coil, and is arranged so as to remove normal mode noise by the Y capacitors Cy1 and Cy2.

  That is, a two-phase circuit is configured by a path through which current is passed from the coil 311 to the coil 321 and a path through which current is passed from the coil 312 to the coil 322. Common mode noise is removed by the choke coil in FIG. It is configured to be removed by the capacitors Cy1 and Cy2.

(Third embodiment)
FIG. 5 is a plan view showing a third embodiment of the present invention.

  Unlike the conductive annular member in the second embodiment, in this embodiment, the conductive annular member 4 has a portion that goes around the coupling portion 20 and the coupling portion 21 and shields between the closed magnetic circuit portions 11 and 12. A conductive annular member combination 42 is provided.

  6 is a cross-sectional view showing a third embodiment of the present invention, and shows a cross-sectional view of the BB surface in FIG.

  The conductive annular member assembly 42 is formed in a plate shape so as to block between the closed magnetic path portions 11 and 12, and the leakage magnetic flux in the region where the closed magnetic path portion 11 and the closed magnetic path portion 12 face each other is caused by the leakage magnetic flux. It will be blocked by.

(Fourth embodiment)
FIG. 7 is a plan view showing a fourth embodiment of the product invention.

  1 in the first embodiment, the closed magnetic path portion 12 is a Japanese-shaped core, the coil 32 is mounted on the middle leg portion of the closed magnetic path portion 12, and the winding axes of the coil 31 and the coil 32 are orthogonal to each other. Is different.

  Since the winding axes of the coil 31 and the coil 32 are orthogonal to each other, the leakage magnetic fluxes do not interfere with each other, so that the magnetic separation effect of each other can be further enhanced.

  Further, since the closed magnetic path portion 12 is configured as a Japanese-shaped core, the cross-sectional area of the magnetic path can be increased, and when the coil 32 is energized, the closed magnetic path portion 11 has a rectangular shape core. Even a large inductance can be obtained.

  The coils 31 and 32 may constitute a common mode choke coil and a noise filter as in the second and third embodiments.

  A noise filter was created by removing the conductive annular member 41 from the configuration of FIGS. 3 and 4 in the second embodiment.

  The inductance due to energization of the coils 311, 312, 321, and 322 was 6.5 mH, and the Y capacitors Cy1 and Cy2 were all 4700 pF, and the attenuation of the noise filter was measured.

  At a frequency of 300 kHz, the attenuation was −60 dB when the conductive annular member 4 was not provided, whereas the attenuation was improved to −80 dB when the conductive annular member 4 was provided.

4, 41 Conductive annular member 5 Regions 11, 12 Closed magnetic path portions 20, 21 Coupling portions 31, 311, 312, 32, 321, 322 Coil 42 Conductive annular member combination Cy1, Cy2 Y capacitor

Claims (5)

A soft magnetic core having at least two closed magnetic path portions and at least one coupling portion;
At least two coils;
Comprising at least one conductive annular member;
The coil is wound around each of the closed magnetic path portions,
One closed magnetic path portion and the other adjacent closed magnetic path portion are coupled by the coupling portion,
One closed magnetic path part, the other closed magnetic path part, and the coupling part are integrally molded,
The choke coil, wherein the conductive annular member is installed so as to go around the coupling portion.   2. The choke coil according to claim 1, wherein the coupling portions are arranged at both end portions in the magnetic flux direction in the closed magnetic path portion in the vicinity of the region in a region between the closed magnetic path portions adjacent to each other. Having a plurality of the coupling parts for coupling the closed magnetic path parts;
The choke coil according to claim 1 or 2, wherein the conductive annular member is installed so as to go around all of the coupling portions. The plurality of conductive annular members constitute a conductive annular member combination by being conductively connected to each other by a plate-like conductor,
The choke coil according to claim 3, wherein the plate-like conductor is provided so as to block between the closed magnetic circuit portions.   5. The choke coil according to claim 1, wherein winding axes of the coils adjacent to each other are orthogonal to each other.

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