JP2016111307A - Common choke coil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a common mode choke coil that is able to reduce core loss and improve DC superposition characteristic while improving normal mode noise reduction effect.SOLUTION: A common mode choke coil 40 comprises: an annular winding core 42; first and second coils 41a, 41b, which are wound around different portions of the winding core 42; and first and second bypass cores 44, 45 provided on the winding core 42, forming a closed magnetic path different from a closed magnetic path formed in the winding core 42, and configured to permit flow of part of a magnetic flux generated by current flowing in the first and second coils 41a, 41b. The winding core 42 is composed by stacking belt-like magnetic members in layers via a non-magnetic layer interposed in it. The first and second bypass iron cores 44, 45 are provided on the winding core 42 such that magnetic flux entering parts 42a, 45a and magnetic flux exiting parts are respectively disposed opposite the staking faces 42a, 42b of the winding core 42.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a common mode choke coil.

  Conventionally, common mode choke coils for noise filters that reduce common mode noise are known. Here, as this coil, as can be seen in Patent Document 1 below, a coil having an improved effect of reducing normal mode noise is also known. Specifically, this coil includes an annular iron core and two windings wound around the iron core. Each of the pair of opposed portions of the inner peripheral surface of the iron core is provided with a projection for forming a closed magnetic path different from the closed magnetic path formed in the iron core. By providing the protrusion, a part of the magnetic flux generated by the current flowing in the winding flows in the another closed magnetic path. For this reason, normal mode inductance can be increased by increasing leakage inductance, and the effect of reducing normal mode noise can be enhanced.

JP-A-4-355906

  By the way, this inventor decided to employ | adopt a cyclic | annular wound iron core as an iron core in which a coil | winding is wound. The wound core is configured by laminating a plurality of belt-like magnetic members with a nonmagnetic layer interposed. Here, for example, when the protrusion is provided on each of the pair of opposed portions of the inner peripheral surface of the wound core, the magnetic flux flowing through the protrusion is concentrated on the inner peripheral surface of the wound core. This is because the nonmagnetic layer is interposed between the magnetic members. If the magnetic flux is concentrated on the inner peripheral surface of the wound core, iron loss (eddy current loss or hysteresis loss) in the coil may increase, or the DC superimposition characteristics of the coil inductance may deteriorate. As described above, the wound iron core type common mode choke coil having the configuration for enhancing the normal mode noise reduction effect still has room for improvement.

  An object of the present invention is to provide a common mode choke coil that can reduce iron loss and improve DC superposition characteristics.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The present invention includes an annular wound core (42; 71) configured by laminating a plurality of band-shaped magnetic members with a nonmagnetic layer interposed therebetween, and a plurality of windings wound around different portions of the wound core ( 41a, 41b) and an iron core that is provided in the wound iron core and forms a closed magnetic circuit different from the closed magnetic circuit formed in the wound iron core, and a part of the magnetic flux generated by the current flowing in the winding A bypass iron core (44, 45; 61, 62, 64, 65; 72, 73) that flows, and the bypass iron core receives a part of a magnetic flux generated by a current flowing through the winding. 44a, 45a; 61a, 62a, 64a, 65a; 72a, 73a), and a magnetic flux outlet (44b, 45b; 61b, 64b; 72b, 73b) for returning the magnetic flux taken in from the magnetic flux inlet to the wound core. Having the magnet Inlet and the laminated surface of each said wound cores of the magnetic flux outlet (42a, 42b; 71a, 71b) while being opposed to, and being provided on the winding core.

  In the above invention, in order to increase the leakage inductance and enhance the effect of reducing the normal mode noise, the wound iron core is provided with the bypass iron core. Here, each of the magnetic flux inlet portion and the magnetic flux outlet portion of the bypass iron core is in a state of facing the laminated surface of the wound iron core. According to this configuration, the leakage magnetic flux flowing through the bypass iron core is linked to the laminated surface. Since the nonmagnetic layer is interposed between the magnetic members, the leakage magnetic flux linked to the laminated surface is distributed not only on the inner peripheral surface of the wound core but also in the stacking direction of the wound core. . For this reason, concentration of magnetic flux on the inner peripheral surface of the wound iron core can be avoided, iron loss can be reduced, and DC superposition characteristics can be improved.

The figure which shows the whole structure of the power converter circuit concerning 1st Embodiment. The figure which shows the equivalent circuit of the secondary side of a power converter circuit. The figure which shows transition of the output current etc. to a battery. The figure which shows the reduction effect of an electric current ripple. The top view of a common mode choke coil. FIG. 6 is a sectional view taken along line 1-1 of FIG. 5. FIG. 6 is a sectional view taken along line 2-2 in FIG. 5. The partial perspective view of a common mode choke coil. The top view of the common mode choke coil concerning related technology. FIG. 10 is a sectional view taken along line 1-1 of FIG. 9. The figure which shows magnetic flux density distribution in the radial direction of a wound iron core. The fragmentary perspective view which shows the concentration aspect of the magnetic flux concerning related technology. The figure which shows the direct current superimposition characteristic of a normal mode inductance component. The figure which shows the direct current superimposition characteristic of a common mode inductance component. The top view of the common mode choke coil concerning 2nd Embodiment. FIG. 16 is a sectional view taken along line 1-1 of FIG. FIG. 16 is a sectional view taken along line 2-2 of FIG. The top view of the common mode choke coil concerning 3rd Embodiment. FIG. 19 is a sectional view taken along line 1-1 of FIG. 2-2 sectional drawing of FIG.

(First embodiment)
Hereinafter, a first embodiment in which a common mode choke coil according to the present invention is applied to a power conversion circuit will be described with reference to the drawings.

  As shown in FIG. 1, the power conversion circuit 10 according to the present embodiment is for supplying a DC voltage input via a first terminal T1 and a second terminal T2 to a battery 20 for charging. The power conversion circuit 10 includes a first capacitor 30, a full bridge circuit 31, a transformer 32, a rectifier circuit 33, a smoothing reactor 34, a second capacitor 35, and a common mode choke coil 40.

  Specifically, a full bridge circuit 31 is electrically connected to the first and second terminals T1 and T2 via the first capacitor 30. The full bridge circuit 31 includes first, second, third, and fourth switches S1, S2, S3, and S4. The full bridge circuit 31 converts the input DC voltage into an AC voltage and applies it to the primary winding 32a of the transformer 32. Apply. In addition, as each switch S1-S4, a voltage control type semiconductor switching element (for example, MOSFET or IGBT) and a current control type semiconductor switching element (for example, bipolar transistor) can be used, for example. In addition, a diode is connected in antiparallel to each of the switches S1 to S4.

  The input side of the rectifier circuit 33 is electrically connected to the secondary winding 32 b of the transformer 32. The rectifier circuit 33 according to the present embodiment is a full-wave rectifier circuit including first, second, third, and fourth diodes D1, D2, D3, and D4. The rectifier circuit 33 has a function of rectifying the alternating current output from the secondary winding 32b into a direct current. The rectifier circuit 33 is not limited to the one provided with a diode, and may be one provided with a switch to perform synchronous rectification.

  The input side of the common mode choke coil 40 is electrically connected to the output side of the rectifier circuit 33 via the smoothing reactor 34 and the second capacitor 35. The battery 20 is electrically connected to the output side of the common mode choke coil 40. The common mode choke coil 40 includes a first winding 41a and a second winding 41b connected to both ends of the second capacitor 35, and a common wound core 42 around which the windings 41a and 41b are wound. ing. The common mode choke coil 40 according to the present embodiment has an enhanced effect of reducing normal mode noise in addition to common mode noise. To reduce the common mode noise, the common mode inductance generated by the magnetic flux linked to both the windings 41a and 41b among the magnetic fluxes generated by the currents flowing through the first and second windings 41a and 41b contributes. Yes. In order to reduce normal mode noise, out of the magnetic flux generated by the current flowing in the first and second windings 41a and 41b, the leakage inductor 43 generated by the magnetic flux linked to one of the windings 41a and 41b. Leakage inductance contributes. In FIG. 1, this leakage inductance is indicated by “L2”. Hereinafter, the reduction of normal mode noise will be described with reference to FIGS.

  FIG. 2 shows an equivalent circuit on the secondary side of the power conversion circuit 10. Here, in FIG. 2, the configuration on the secondary side including the transformer 32 and the rectifier circuit 33 is replaced with the power source 21. In FIG. 2, the current flowing through the smoothing reactor 34 is indicated by “IL1”, and the current flowing through the leakage inductor 43 is indicated by “IL2”. 3A shows the transition of the output voltage of the power source 21, FIG. 3B shows the transition of IL1 and IL2, and FIG. 4 shows the relationship between the leakage inductance L2 and the output current ripple. By increasing the leakage inductance L2, the ripple of the output current from the power conversion circuit 10 to the battery 20 can be reduced.

  Next, the structure of the common mode choke coil 40 will be described in comparison with related technology. First, the structure of the common mode choke coil 40 will be described with reference to FIGS. 6 shows a cross-sectional view taken along line 1-1 of FIG. 5, and FIG. 7 shows a cross-sectional view taken along line 2-2 of FIG. FIG. 8 is a perspective view showing a part of the common mode choke coil 40. In FIG. 7, the first and second windings 41a and 41b are not shown. Further, in FIG. 8, the cross section of the member is not hatched.

  As illustrated, the wound iron core 42 according to the present embodiment is a toroidal core having an annular shape. Of the wound core 42, the first winding 41a is wound on one of a pair of opposed portions sandwiching the inner circumferential space of the wound core 42, and the second winding 41b is wound on the other. Yes. The wound iron core 42 is configured by alternately laminating a plurality of strip-shaped magnetic members and nonmagnetic layers having magnetic insulation properties in the radial direction. The magnetic member is made of a soft magnetic material such as an electromagnetic steel plate, and specifically, for example, Finemet (registered trademark) or amorphous can be used. In the present embodiment, the nonmagnetic layer is made of a material having a relative permeability smaller than 1, such as a diamagnetic material. Incidentally, the first and second windings 41 a and 41 b may be wound around the wound core 42 via a bobbin attached to the wound core 42. In the present embodiment, one of the pair of flat surfaces of the wound core 42 is referred to as a first laminated surface 42a, and the other is referred to as a second laminated surface 42b.

  The common mode choke coil 40 further includes a first bypass iron core 44 and a second bypass iron core 45. In the present embodiment, each of the bypass iron cores 44 and 45 has the same shape, specifically, has a bar shape and a rectangular cross section.

  A first magnetic flux inlet portion 44a extending in a direction orthogonal to the longitudinal direction is integrally provided at one end of the main body portion extending in the longitudinal direction of the first bypass iron core 44, and the longitudinal direction is provided at the other. The first magnetic flux outlet portion 44b extending in a direction orthogonal to is integrally provided. The first bypass iron core 44 is made of a magnetic material such as ferrite, for example. One of the pair of portions facing each other in the radial direction of the first laminated surface 42a is mechanically connected to the end (end surface) of the first magnetic flux inlet portion 44a via the first gap adjusting member 46a. Is mechanically connected to the end (end face) of the first magnetic flux outlet 44b via the second gap adjusting member 46b. The first bypass iron core 44 has a shape that does not enter the inner circumferential space of the wound iron core 42. In other words, the first bypass iron core 44 has a shape that does not overlap with the wound iron core 42 in the width direction of the magnetic member constituting the wound iron core 42. Thereby, the first bypass iron core 44 is provided in a state of being spanned over the wound iron core 42. In the present embodiment, each of the gap adjusting members 46a and 46b is made of a material having a relative permeability smaller than 1, such as a diamagnetic material. Each gap adjusting member 46a, 46b is provided for inductance adjustment.

  Similar to the first bypass iron core 44, a second magnetic flux inlet 45 a is integrally provided at one end of the main body portion extending in the longitudinal direction of the second bypass iron core 45, and the second A magnetic flux outlet 45b is provided integrally. The second bypass iron core 45 is made of a magnetic material such as ferrite, for example. The end portion (end surface) of the second magnetic flux inlet portion 45a is mechanically connected to the second laminated surface 42b via the third gap adjusting member 47a, and the end portion (end surface) of the second magnetic flux outlet portion 45b is It is mechanically connected to the second laminated surface 42b via the 4 gap adjusting member 47b. The second bypass iron core 45 has a shape that does not enter the inner circumferential space of the wound iron core 42. As a result, the second bypass iron core 45 is provided in a state of being stretched over the wound iron core 42. In the present embodiment, each of the gap adjusting members 47a and 47b is made of a material having a relative permeability smaller than 1, such as a diamagnetic material. Each gap adjustment member 47a, 47b is provided for inductance adjustment.

  When a current flows through each of the first winding 41a and the second winding 41b, a closed magnetic circuit (hereinafter referred to as a main closed magnetic circuit) is formed around the wound core 42. Further, by providing the first bypass iron core 44, a part of the magnetic flux flowing through the main closed magnetic circuit is a closed magnetic circuit passing through the first magnetic flux inlet 44a and the first magnetic flux outlet 44b, Flows through an independent first closed magnetic circuit. On the other hand, by providing the second bypass iron core 45, a part of the magnetic flux flowing through the main closed magnetic circuit is a closed magnetic circuit passing through the second magnetic flux inlet 45a and the second magnetic flux outlet 45b, It flows through a second closed magnetic circuit independent of the first closed magnetic circuit.

  Next, related technologies will be described with reference to FIGS. 9 and 10. In FIGS. 9 and 10, the configuration of the wound iron core and the first and second windings are the same as those in the present embodiment. For this reason, the same reference numerals as those shown in FIGS. 5 to 8 are given to these members for convenience.

  As shown in the figure, a common mode choke coil 50 according to the related art includes a rod-shaped bypass iron core 51. Each end of the bypass iron core 51 is mechanically connected to the inner peripheral surface of the wound iron core 42 via a gap adjusting member.

  Then, the effect of this embodiment is demonstrated using FIGS. 11-14.

  FIG. 11 shows the magnetic flux density distribution in the radial direction X of the wound core 42. X = 0 indicates the outer peripheral edge of the wound iron core 42, and X = 5 indicates the inner peripheral edge of the wound iron core 42 (see FIG. 8 above). Further, in FIG. 11, related technology 2 is a configuration in which the bypass iron core 51 is removed from the configuration of the related technology shown in FIGS. 9 and 10.

  As shown in FIG. 11, according to the present embodiment, the magnetic flux is not concentrated on the inner peripheral surface of the wound core 42 and eddy current is less likely to be generated in the inner peripheral surface as compared with the related art (see FIG. 12). ). As a result, as shown in FIGS. 13 and 14, it is possible to suppress a decrease in normal mode inductance and common mode inductance. Hereinafter, this reason will be described.

  The normal mode inductance Ln can be expressed by the following equation (eq1).

In the above equation (eq1), “R” represents the magnetic resistance, “lg” represents the gap length, “lc” represents the magnetic path length of the iron core, “Sg” represents the gap area, and “Sc” represents The cross-sectional area of the iron core is indicated, “μ0” indicates the magnetic permeability in vacuum, “μ” indicates the relative magnetic permeability, and “N” indicates the number of turns of the winding.

  In this embodiment, as shown in FIG. 11, the magnetic flux can be distributed inside the wound iron core 42 in the radial direction. This is because the magnetic flux inlet portions 44a and 45a and the magnetic flux outlet portions 44b and 45b are opposed to the respective laminated surfaces 42a and 42b of the wound core 42, whereby the magnetic flux interlinking with the respective laminated surfaces 42a and 42b in the wound core 42. This is because the flow of is regulated by the nonmagnetic layer. By distributing the magnetic flux in the radial direction, in the above equation (eq1), the cross-sectional area Sc of the wound iron core 42 is substantially increased, and the relative permeability μ is decreased as the direct current flowing in the winding increases. Becomes moderate. For this reason, the normal mode inductance Ln according to the present embodiment gradually decreases as the DC current increases, as shown in the DC superposition characteristics of FIG.

  On the other hand, in the related art, although the magnetic flux contributing to the normal mode inductance flowing through the bypass iron core 51 is linked to the inner peripheral surface of the wound iron core 42, the non-magnetic material is more radially outer than the inner peripheral surface in the wound iron core 42. Due to the presence of the layer, the magnetic flux interlinking with the inner peripheral surface is prevented from flowing into the inside of the wound core 42 in the radial direction. For this reason, it concentrates on the inner peripheral surface of the wound iron core 42 (see FIG. 12 above), the sectional area Sc of the wound iron core 42 is substantially reduced, and the degree of decrease in the relative permeability μ with the increase of the direct current. Also grows. As a result, the normal mode inductance according to the related art is smaller than that according to the present embodiment.

  Furthermore, according to the present embodiment, as shown in FIG. 14, the common mode inductance is also increased as compared with the related art. This is because the common mode inductance increases in proportion to the relative permeability μ and the degree of decrease in the relative permeability μ accompanying the increase of the DC current in the present embodiment is the relative permeability accompanying the increase of the DC current in the related art. This is because it is smaller than the degree of decrease in μ.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) With each of the magnetic flux inlet portions 44a and 45a and each of the magnetic flux outlet portions 44b and 45b opposed to the laminated surfaces 42a and 42b of the wound core 42, the bypass cores 44 and 45 are connected to the wound core 42. Provided. For this reason, it is possible to increase the leakage inductance that acts as a normal mode inductance while suppressing local concentration of magnetic flux on the inner peripheral surface of the wound core 42. Thereby, an iron loss can be reduced or direct current superimposition characteristics can be improved.

  In particular, in this embodiment, the respective end faces of the magnetic flux inlet portions 44a and 45a and the magnetic flux outlet portions 44b and 45b are opposed to only the laminated surfaces 42a and 42b of the wound iron core 42, thereby reducing the iron loss. This greatly contributes to increasing the size and improving the DC superposition characteristics.

  Furthermore, according to the present embodiment, the gap between the wound core 42 and the bypass cores 44 and 45 can be easily adjusted as compared with the related art. That is, the winding core generally has a large manufacturing tolerance, and the distance between a pair of opposed portions on the inner peripheral surface of the winding core is likely to vary. For this reason, in the configuration in which the bypass iron core is provided between the pair of opposed portions of the inner peripheral surface as in the related art shown in FIGS. 9 and 10, the gap between the bypass iron core and the inner peripheral surface is reduced. Adjustment becomes difficult. Here, it is also conceivable to adjust the length of the bypass core in accordance with the distance between the pair of opposed portions of the inner peripheral surfaces of the mass-produced wound cores. In this case, however, an extra step of adjusting the length of the bypass iron core is added. On the other hand, according to the present embodiment, for example, since the tolerance of flatness of each of the laminated surface of the wound core and the magnetic flux inlet and outlet is small, the gap can be easily adjusted without adding an extra step. can do.

  (2) Each of the bypass iron cores 44 and 45 has a shape that does not enter the inner circumferential space of the wound core 42. When each of the bypass iron cores 44 and 45 has a shape that enters the inner peripheral space of the wound core 42, a part of the magnetic flux flowing through each bypass iron core 44 and 45 easily flows to the inner peripheral surface of the wound iron core 42. . At this time, there is a possibility that the effect of reducing the iron loss and the effect of improving the direct current superimposition characteristic are lowered. Here, each bypass iron core 44, 45 is shaped so as not to enter the inner circumferential space of the wound core 42, so that each bypass iron core 44, 45 can be separated from the inner circumferential surface of the wound core 42. it can. For this reason, it is possible to reduce the amount of magnetic flux flowing from the bypass iron cores 44 and 45 to the inner peripheral surface of the wound iron core 42, and to enhance the effect of reducing the iron loss and improving the direct current superposition characteristics.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In this embodiment, the shape and number of bypass iron cores are changed.

  15 to 17 show a common mode choke coil according to the present embodiment. 15 to 17, the same members as those shown in FIGS. 5 to 7 are denoted by the same reference numerals for the sake of convenience. In FIG. 17, the first and second windings 41a and 41b are not shown.

  As shown in the figure, the common mode choke coil 60 includes a wound core 42, first and second windings 41a and 41b, upper first and second bypass iron cores 61 and 62, and lower first and second bypasses. Iron cores 64 and 65 are provided.

  The upper first bypass iron core 61 has a thin plate semicircular shape. One of the end portions of the upper first bypass iron core 61 is integrally provided with an upper first magnetic flux inlet 61a extending in a direction orthogonal to the flat surface of the upper first bypass iron core 61, and on the other side, The 1st magnetic flux exit part 61b is provided integrally. The upper second bypass iron core 62 also has a thin plate semicircular shape. One of the end portions of the upper second bypass iron core 62 is integrally provided with an upper second magnetic flux inlet portion 62a, and the other is integrally provided with an upper second magnetic flux outlet portion (not shown). ing.

  Each of the upper first magnetic flux inlet portion 61a and the second magnetic flux inlet portion 62a is mechanically connected to the first laminated surface 42a via the first gap adjusting member 63a, and the upper first magnetic flux outlet portion 61b and the second magnetic flux. Each of the outlet portions is mechanically connected to the first laminated surface 42a via the second gap adjusting member 63b.

  The lower first bypass iron core 64 has a thin plate semicircular shape. Similarly to the upper first bypass iron core 61, a lower first magnetic flux inlet portion 64a and a lower first magnetic flux outlet portion 64b are integrally provided at the end of the lower first bypass iron core 64. . The lower second bypass iron core 65 has a thin plate semicircular shape. Similarly to the upper second bypass iron core 62, a lower second magnetic flux inlet 65a and a lower second magnetic flux outlet (not shown) are integrally formed at the end of the lower second bypass iron core 65. Is provided.

  Each of the lower first magnetic flux inlet portion 64a and the second magnetic flux inlet portion 65a is mechanically connected to the second laminated surface 42b via the third gap adjusting member 63c, and the lower first magnetic flux outlet portion 64b and the second Each of the two magnetic flux outlet portions is mechanically connected to the second laminated surface 42b via the fourth gap adjusting member 63d.

  According to the present embodiment described above, the same effect as that of the first embodiment can be obtained.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment. In this embodiment, as shown in FIGS. 18 to 20, the shape of the wound iron core is a rectangular (rectangular) ring. 18 to 20, the same members as those shown in FIGS. 5 to 7 are given the same reference numerals for the sake of convenience. In FIG. 20, the winding is not shown.

  As shown in the figure, the common mode choke coil 70 includes a wound iron core 71, first and second windings 41 a and 41 b, and first and second bypass iron cores 72 and 73. In the wound core 71, the first winding 41 a is wound on one of the pair of opposed portions, and the second winding 41 b is wound on the other. Incidentally, in the present embodiment, one of the pair of flat surfaces of the wound core 71 is referred to as a first stacked surface 71a, and the other is referred to as a second stacked surface 71b.

  Each of the bypass iron cores 72 and 73 has a rod shape as in the first embodiment. A first magnetic flux inlet portion 72 a and a first magnetic flux outlet portion 72 b are integrally provided at the longitudinal direction end of the first bypass iron core 72. The first magnetic flux inlet portion 72a is mechanically connected to the first laminated surface 71a via the first gap adjusting member 74a, and the first magnetic flux outlet portion 72b is connected to the first laminated surface via the second gap adjusting member 74b. 71a is mechanically connected.

  A second magnetic flux inlet portion 73 a and a second magnetic flux outlet portion 73 b are integrally provided at the longitudinal direction end of the second bypass iron core 73. The second magnetic flux inlet portion 73a is mechanically connected to the second stacked surface 71b via a third gap adjusting member 74c, and the second magnetic flux outlet portion 73b is connected to the second stacked surface via a fourth gap adjusting member 74d. 71b is mechanically connected.

  According to the present embodiment described above, the same effect as that of the first embodiment can be obtained.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  -The number of windings wound around the wound iron core is not limited to two and may be three or more. Specifically, for example, when the number of windings is three, a three-phase common mode choke coil in which a winding is wound around each of three different parts of the toroidal core can be employed as the common mode choke coil. .

  In each of the above embodiments, a magnetic gap may be formed between the magnetic flux inlet and the magnetic flux outlet of the bypass iron core. In this case, the gap between the bypass core and the laminated surface of the wound core is not essential.

  In each of the above embodiments, when the bypass iron core is made of a material having a small relative permeability, such as a dust core, a magnetic gap between the bypass iron core and the laminated surface of the wound iron core is not essential. .

  In each of the above embodiments, the number of bypass cores provided in the wound core is two or four, but is not limited thereto, and may be one, three, or five or more.

  In each of the above embodiments, a magnetic gap may be formed between at least one of the magnetic flux inlet portion and the magnetic flux outlet portion and the laminated surface.

  Further, instead of forming a magnetic gap by interposing a gap adjusting member, an air gap may be formed. In this case, for example, the bypass iron core may be attached to the wound iron core by some attachment means such as attaching the bypass iron core to the bobbin attached to the wound iron core.

  In each of the above embodiments, the bypass iron core is configured in such a shape that each of the magnetic flux inlet portion and the magnetic flux outlet portion of the bypass iron core faces only the laminated surface of the wound iron core, but the present invention is not limited thereto. In addition to the laminated surface of the wound core, each of the magnetic flux inlet portion and the magnetic flux outlet portion may be configured, for example, in a shape that faces the inner peripheral surface of the wound core. Even in this case, it is possible to obtain the effects according to the effects of the above embodiments.

  -The shape of the wound core is not limited to those exemplified in the above embodiments.

  40 ... common mode choke coil, 42 ... wound iron core, 44 ... first bypass iron core, 45 ... second bypass iron core.

Claims (6)

An annular wound core (42; 71) configured by laminating a plurality of belt-like magnetic members with a non-magnetic layer interposed therebetween;
A plurality of windings (41a, 41b) wound around different portions of the wound core;
A bypass core (44) that is provided in the wound iron core and forms a closed magnetic circuit different from the closed magnetic circuit formed in the wound iron core, and allows a part of the magnetic flux generated by the current flowing in the winding to flow. , 45; 61, 62, 64, 65; 72, 73),
The bypass iron core is taken in from a magnetic flux inlet portion (44a, 45a; 61a, 62a, 64a, 65a; 72a, 73a) that takes in a part of the magnetic flux generated by the current flowing in the winding, and the magnetic flux inlet portion. Magnetic flux outlet portions (44b, 45b; 61b, 64b; 72b, 73b) for returning the magnetic flux returned to the wound iron core, and each of the magnetic flux inlet portion and the magnetic flux outlet portion is a laminated surface (42a, 42b) of the wound iron core. A common mode choke coil provided on the wound core in a state opposed to 71a, 71b).   2. The common mode choke coil according to claim 1, wherein the bypass iron core has a shape that does not enter an inner circumferential space of the wound iron core in a width direction of the magnetic member constituting the wound iron core.   3. The common mode choke coil according to claim 2, wherein the bypass iron core is formed so as to be bridged between a pair of portions facing each other with the inner space on the laminated surface of the wound core. . The bypass iron core (44, 45; 72, 73) has a rod shape,
3. One of the both end portions of the bypass core is the magnetic flux inlet portion (44a, 45a; 72a, 73a), and the other is the magnetic flux outlet portion (44b, 45b; 72b, 73b). 3. The common mode choke coil according to 3.   5. The bypass iron core according to claim 1, wherein each of the magnetic flux inlet portion and the magnetic flux outlet portion is provided on the wound iron core in a state where only the laminated surface of the wound iron core is opposed to the bypass iron core. Common mode choke coil as described.   The common mode according to any one of claims 1 to 5, wherein a magnetic gap is formed between at least one of the magnetic flux inlet portion and the magnetic flux outlet portion and a laminated surface of the wound core. choke coil.