JP6445810B2 - Interleaving choke coil - Google Patents

Description

The present invention relates to an interleave choke coil that employs a magnetic core structure in which a pair of magnetic cores formed in an E shape in a side view are arranged to face each other, with a middle leg portion around which a winding is wound.

  Patent Document 1 discloses a PFC choke coil for interleaving that has a 2-in-1 structure that substantially functions as two independent choke coils, and that can reduce costs and downsize external dimensions. .

  The PFC choke coil for interleaving is configured as a so-called EIE type, and includes a middle leg portion, an outer leg portion located on at least both sides of the middle leg portion, and a communication portion that connects the middle leg portion and the outer leg portion. The first and second magnetic cores, the first coil winding wound around the outer periphery of the middle leg portion of the first magnetic core, and the second coil winding wound around the middle leg portion of the second magnetic core And a third magnetic core having a flat plate shape, and the first and second magnetic cores have outer legs abutting each other across the third magnetic core, and each middle leg and the above-mentioned A gap is provided between the third magnetic core, the current directions of the first coil winding and the second coil winding are the same, and the magnetic fluxes passing through the third magnetic core due to the respective currents are opposite to each other. Is set.

  Patent Document 2 includes a magnetic core and a plurality of windings as an interleaved PFC choke coil that can obtain a good output and can be reduced in size. The magnetic core includes a plurality of windings each of which is wound with a plurality of windings. Each of the winding arms, at least one common arm that forms a magnetic flux loop with each of the winding arms, and a pair of bases, and the winding arm and the common arms are between the pair of bases. An inductor configured to be positioned is disclosed.

JP 2010-258395 A Special table 2013-501346 gazette

  However, when the configuration disclosed in Patent Document 1 described above is adopted, it is necessary to use two types of cores, an E-shaped magnetic core and an I-shaped magnetic core, and accordingly, two types of molds are required. There was a problem that the mold cost increased.

  In addition, in order to ensure the accuracy of the contact surface of the I-shaped magnetic core that is abutted with the outer leg of the E-shaped magnetic core, a process such as polishing the surface of the I-shaped magnetic core occurs, which increases the processing cost. There was also a problem.

  Further, when the configuration disclosed in Patent Document 2 is adopted, there is a problem in that a loss due to a large leakage magnetic flux occurs because the periphery of the winding is greatly exposed.

In view of the above-described problems, an object of the present invention is to provide an interleave choke coil that can reduce leakage magnetic flux and can be manufactured at low cost.

To achieve the above object, a first characteristic feature of the interleave choke coil according to the present invention, as described in claim 1 of the document in the claims, a plurality of windings, each winding wound The interleaved choke coil is provided with a plurality of middle leg portions, and a pair of magnetic cores formed in an E shape in a side view are arranged to face each other, and the pair of magnetic cores includes a single base portion, A plurality of middle legs standing along the longitudinal direction of the base, and plate-like outer legs standing along both longitudinal sides of the base so as to cover each middle leg A slit between the middle legs of the base so that the magnetic flux generated in one middle leg wound with the individual winding does not interlink with the winding wound around the other middle leg. The high magnetoresistive region is formed.

A plurality of pairs of middle leg portions are formed between the pair of base portions along the longitudinal direction, and a winding is wound around each. The magnetic flux generated by one winding is formed along a magnetic path having a low magnetic resistance passing through the pair of middle and outer legs, and does not pass through the high magnetic resistance region. There is no interlinkage with the winding wound around the leg .

  Since the plurality of pairs of middle legs are magnetically shielded by the plate-like outer legs standing along the longitudinal sides of the base, the leakage flux of each winding is sufficiently reduced. Become. Furthermore, the magnetic core structure can be manufactured with a common mold because a pair of magnetic cores formed in the same E-shape in a side view can be disposed opposite to each other, and the joint surfaces of the magnetic core structure are the same in the polishing process. Therefore, it is possible to polish with high accuracy without variation, and the troublesome work of polishing the surface uniformly like an I-shaped magnetic core becomes unnecessary.

The magnetic flux generated by one winding does not interlink with the winding wound around the other middle leg through the high magnetic resistance region formed by the slit formed in the base, and the pair of the center leg and ing as being formed along the magnetic path of low reluctance through the outer legs. Even if heat generation magnetic core structure such as this, it becomes possible to also include a slit cooling capacity to function as inlet or outlet holes around the air flow. Accordingly, the leakage magnetic flux can be reduced, and the interleaving choke coil can be provided at a low cost.

As described in claim 2, the second characteristic configuration is that, in addition to the first characteristic configuration described above, the slit is filled with a nonmagnetic material.

  For example, when the slit is filled with hard glass, ceramics, or the like as a non-magnetic material, the mechanical strength can be increased as compared with the case where a shield region having a high magnetic resistance is formed in the gap.

In the third feature configuration, as described in the third aspect, in addition to the first or second feature configuration described above, the standing length of the middle leg portion is shorter than that of the outer leg portion. The high magnetic resistance region is further provided by a gap formed between the middle legs in a state where the outer legs arranged opposite to each other are in contact with each other.

  The magnetic flux generated by one winding is formed along a magnetic path with low magnetic resistance that passes through the pair of middle and outer legs without being magnetically saturated by the gap formed in the middle leg. In addition, since the gap formed in the other pair of middle legs becomes a high magnetic resistance region, it does not interlink with the winding wound around the other middle leg through such a region. Absent.

In the fourth feature configuration, as described in claim 4 , in addition to any one of the first to third feature configurations described above, the middle leg portion, the base portion, and the outer leg portion are formed of magnetic powder. It is composed of a single material of either body or ferrite.

  If all of the middle leg, base and outer legs are made of the same material, they can be manufactured with a simple manufacturing process, and can be manufactured at a low cost if they are made of powdered magnetic material such as iron dust or sendust. If ferrite is used, an inexpensive magnetic core structure with low core loss can be realized.

In the fifth feature configuration, as described in claim 5 , in addition to any of the first to fourth feature configurations described above, the middle leg portion is more resistant to magnetic resistance than the base portion and the outer leg portion. Is made of a high material.

For example, if the middle leg is made of a material having a higher magnetic resistance than others, such as the middle leg around which the winding is wound is made of powder magnetic material and the base and the outer leg are made of ferrite, the One of the magnetic flux generated by the winding ing so can be more reliably prevented interlinked with wound windings to another center leg.

As described above, according to the present invention, it is possible to provide an interleave choke coil that can reduce leakage magnetic flux and can be manufactured at low cost.

Explanatory diagram of interleaved PFC circuit (A) is a front view of the magnetic core used for the magnetic core structure by this invention, (b) is the side view, (c) is the perspective view (A) to (c) are assembly explanatory views of the magnetic core structure. (A), (b) is explanatory drawing of the choke coil for interleaving using a magnetic core structure 2A and 2B show another embodiment, in which FIG. 3A is a front view of a magnetic core used in the magnetic core structure according to the present invention, FIG. The other embodiment is shown, (a), (b) is an explanatory diagram of a choke coil for interleaving using a magnetic core structure FIG. 4A shows another embodiment, in which FIG. 5A is a front view of a magnetic core used in the magnetic core structure according to the present invention, and FIG. The other embodiment is shown, (a), (b) is an explanatory diagram of a choke coil for interleaving using a magnetic core structure Fig. 4 shows another embodiment, (a) is a front view of an interleave choke coil using a magnetic core structure according to the present invention, and (b) is a side view of the same.

Hereinafter, an interleave choke coil according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a PFC circuit 1 in which an interleave choke coil according to the present invention is used. The PFC circuit 1 includes a first booster circuit 2 including a choke coil L1, a switch element SW1, a diode D1, and a capacitor C, and a second booster circuit 3 including a choke coil L2, a switch element SW2, a diode D2, and a capacitor C. It is prepared for. The common capacitor C is configured to be charged by the two booster circuits 2 and 3.

  The pulsating voltage Vi obtained by full-wave rectifying the AC voltage Va by the rectifier circuit 4 is input to the input terminals IN1 and IN2. When the switch element SW1 is turned on by a control circuit (not shown), the choke coil L1 is charged by the pulsating voltage Vi. When the switch element SW1 is turned on, the capacitor is charged with the voltage charged to the choke coil L1 together with the pulsating voltage Vi. C is charged.

  Similarly, when the switch element SW2 is turned on by a control circuit (not shown), the choke coil L2 is charged by the pulsating voltage Vi, and when the switch element SW2 is turned on, the choke coil L2 is charged together with the pulsating voltage Vi. The capacitor C is charged with the voltage.

  The switches SW1 and SW2 are continuously turned on / off with a phase difference of 180 degrees by a control circuit (not shown), and a DC current with a small ripple charged in the capacitor C is output from the output terminals OUT1 and OUT2.

  FIG. 1 shows a two-phase PFC circuit 1. For example, four booster circuits are provided, and switch elements of each booster circuit are continuously on / off controlled at a phase difference of 90 degrees. Alternatively, three booster circuits may be provided, and the switch elements of each booster circuit may be continuously turned on / off at a phase difference of 120 degrees.

  2 (a), (b), (c) and FIGS. 3 (a), (b), (c), the magnetic core structure 10 constituting the choke coil 2 used in such a PFC circuit 1 is shown. It is shown.

  As shown in FIGS. 2A, 2B, and 2C, the magnetic core structure 10 includes a pair of magnetic cores 11 formed in an E shape in a side view and arranged to face each other. The magnetic core 11 includes a base 13 and a plurality of middle legs 12 (12a in the present embodiment, although two are provided in the present embodiment, but two or more may be provided) erected along the longitudinal direction of the base 13. , 12b) and plate-like outer leg portions 14 erected along both longitudinal sides of the base portion 13 so as to cover the middle leg portions 12 (12a, 12b). The middle leg portion 12 (12a, 12b) and the outer leg portion 14 are configured so that the standing length H from the base portion 13 is equal, and the end surfaces thereof are polished flat.

  As shown in FIGS. 3A, 3B, and 3C, the middle leg portion 12 (12a, 12b) provided upright on the base portion 13 is formed in a columnar shape, and a cylindrical bobbin 21 (21a, 21b). ) Of the middle leg portion 12 (12a, 12b) and the outer leg portion 14 of each other in a state where the windings 20 (20a, 20b) wound around the middle leg portion 12 (12a, 12b) are inserted. Opposite arrangement is made so that the end faces are in close contact.

  In this way, a high magnetic resistance region is formed in the base 13 so that the magnetic flux generated in one middle leg 12a around which the winding 20a is wound does not interlink with the winding 20b wound around the other middle leg 12b. 15 is formed. The high magnetoresistive region 15 includes a slit 15a formed at a central portion of the adjacent middle leg portion 12a and having a width W longer than the leg width W1 of the middle leg portion 12 (see FIG. 2A).

  As shown in FIGS. 4A and 4B, the magnetic flux φa generated by one winding 20a is formed in the base 13 and passes through a slit longer than the leg width of the middle leg 12a, that is, the high magnetoresistance region 15. Thus, there is no interlinkage with the winding 20b wound around the other middle leg 12b (see FIG. 4A), and the magnetic resistance passing through the pair of middle leg 12a and the outer leg 14 is reduced. It is formed along the low magnetic path (see FIG. 4B). Even if such a magnetic core structure generates heat, the slit can function as an inflow hole or an outflow hole for the surrounding air flow and can also have a cooling capacity.

  As described with reference to FIG. 2A, the slit 15a is preferably configured to have a width W longer than the leg width W1 of the middle leg portion 12, but the magnetic flux φa generated by one winding 20a. However, the shape is not particularly limited as long as there is no interlinkage with the winding 20b wound around the other middle leg portion 12b.

  Such a plurality of pairs of middle legs 12 are magnetically shielded by plate-like outer legs 14 erected along both longitudinal sides of the base 13, so that the leakage magnetic flux of each winding 20 is sufficiently reduced. Will come to be. Furthermore, the magnetic core structure 10 can be manufactured with a common mold because the pair of magnetic cores 11 formed in the same E-shape in a side view can be disposed opposite to each other, and the joint surfaces are the same. Polishing can be accurately performed in the polishing process, and a complicated operation such as polishing the surface uniformly like an I-shaped magnetic core becomes unnecessary.

  It is preferable that the slit that becomes the high magnetoresistive region 15 is filled with a nonmagnetic material. For example, the slit is filled with hard glass, ceramics, or the like as a nonmagnetic material, thereby forming a shielding region with high magnetic resistance in the gap. As a result, the mechanical strength can be increased as compared with the case of doing so.

  The middle leg part 12, the base part 13 and the outer leg part 14 are preferably made of a single material of either powder magnetic material or ferrite. When the same material is used, a simple mold and It can be easily manufactured in the manufacturing process. For example, it can be manufactured at a low cost if it is made of a powder magnetic material such as iron dust or sendust, and a magnetic core structure with low cost and low core loss can be realized by using ferrite.

  Contrary to the above, the middle leg portion 12 may be made of a material having a higher magnetic resistance than the base portion 13 and the outer leg portion 14. For example, the middle leg portion 12 around which the winding 20 is wound is made of powder magnetic material. If the middle leg 12 is made of a material having a higher magnetic resistance than the other, such as a base 13 and an outer leg 14 made of ferrite, the magnetic flux generated by one winding 20a is transferred to the other middle leg. Interlinkage with the winding 20b wound around the portion can be more reliably prevented.

Hereinafter, another embodiment will be described.
As shown in FIG. 5, the standing length H of the middle leg portion 12 is shorter than the standing length H1 of the outer leg portion 14, and the outer leg portions 14 that are opposed to each other are in contact with each other. The high magnetoresistive region 15 may be configured by a gap G formed between the leg portions 12a and 12b.

  As shown in FIG. 6, the magnetic flux φa generated by one winding 20a is not magnetically saturated by the gap G formed in the middle leg 12a, and the pair of middle legs 12a, 12a and the outer legs The gap G is formed along the magnetic path having a low magnetic resistance passing through the portion 14 (see FIG. 6B), and the gap G formed in the other pair of middle leg portions 12b and 12b becomes the high magnetic resistance region 15. There is no possibility of interlinking with the winding 20b wound around the other middle leg portion 12b through such a region (see FIG. 6A).

  7, 8 and 9 show still another embodiment. In the present embodiment, like FIG. 5 described above, the standing length H of the middle leg portion 12 is shorter than the standing length H1 of the outer leg portion 14, and the outer leg portions 14 arranged to face each other are formed. The high magnetoresistive region 15 is constituted by a gap G formed between the middle leg portions 12a and 12b in a contact state.

  In the above-described embodiment, the middle leg 12 is laminated on the base 13 on the flat plate. However, in this embodiment, the middle leg 12 is embedded in the hole formed in the base 13 on the flat plate. It is attached as follows. Further, the outer leg 14 is not flat, but the inner surface is formed in a cylindrical shape coaxial with the columnar middle leg 12, and the cross-sectional area thereof is formed approximately ½ of the cross-sectional area of the middle leg 12. Has been. The middle leg, base, and outer leg are all made of ferrite.

  As shown in FIG. 8, the magnetic flux φa generated by one winding 20a is not magnetically saturated by the gap G formed in the middle leg portion 12a, and the pair of middle leg portions 12a, 12a and the outer legs. The gap G is formed along the magnetic path having a low magnetic resistance passing through the portion 14 (see FIG. 8B), and the gap G formed in the other pair of middle leg portions 12b and 12b becomes the high magnetic resistance region 15. The winding 20b wound around the other middle leg portion 12b through such a region is not linked (see FIG. 8A).

  FIG. 9 shows a configuration including a terminal block 30 made of an insulating resin made of phenol resin or the like. On the terminal block 30, pins 31 to which the respective winding terminals are connected are protruded.

  In the above-described embodiments, the middle leg portion has been described as an example in which the cross section is formed into a perfect circular column shape. However, the middle leg portion may be an elliptical or oval column shape in cross section. You may form in prismatic shapes, such as a quadrangle | tetragon, a hexagon, and an octagon.

  In the above-described embodiment, the high magnetic resistance region is formed by the slit formed in the base or the gap formed in the middle leg, and the magnetic flux generated in one middle leg around which the winding is wound is transferred to the other middle leg. However, the high magnetic resistance region is not limited to a mode in which gaps and slits are formed, and the middle leg portion is more magnetic than the base and outer leg portions. You may be comprised with the material with high resistance.

  In this case, the magnetic flux generated by one winding is formed along a magnetic path having a low magnetic resistance passing through the high magnetic resistance region and the outer leg that constitute the middle leg, and the other pair of middle legs is The high magnetic resistance region to be configured does not interlink with the winding wound around the other middle leg portion through such a region.

  In the above-described embodiment, the interleave choke coil including the magnetic core structure 11 according to the present invention and having the winding 20 wound around each middle leg portion 12 function as a two-phase PFC choke coil has been described as an example. The choke coil for interleaving according to the present invention is not limited to two phases, and can correspond to a three-phase or four-phase or more multiphase. In this case, the middle leg portion 12 extends along the longitudinal direction of the base portion 13. It is sufficient that three or four or more erected portions are provided, and slits that become the high magnetic resistance regions 15 are formed in the base portions 13 between the middle leg portions 12. Further, a gap G may be formed in each middle leg portion 12 instead of the slit.

  It is also possible to construct a transformer with a magnetic core structure 11 according to the invention. In this case, a primary winding and / or a secondary winding may be wound around each middle leg portion 12, and mutual induction of each other's transformer can be avoided by the presence of the high magnetic resistance region. When the primary winding is wound on one of the two middle leg portions 12 adjacent to each other in the longitudinal direction of the base portion 13 and the secondary winding is wound on the other side, the two middle leg portions are wound. It is not necessary to form a high magnetoresistive region between the two middle legs 12, and a high magnetoresistive region may be formed between the two middle legs 12 and the other two middle legs 12.

  It should be noted that each of the above-described embodiments is merely an example of the present invention, and it is needless to say that the specific configuration and the like of each block can be appropriately changed and designed within the scope of the effects of the present invention.

10: Magnetic core structure 11: Magnetic core 12: Middle leg 13: Base 14: Outer leg 15: High magnetoresistance region 20: Winding

Claims (5)

A plurality of windings, comprising a plurality of center leg of each coil is wound, a interleave choke coil pair of the magnetic core formed in E-shape in side view is opposed,
The pair of magnetic cores include a single base, a plurality of middle legs standing along the longitudinal direction of the base, and both longitudinal sides of the base so as to cover the middle legs. With plate-like outer legs standing upright,
In order to prevent the magnetic flux generated in one middle leg part, on which the windings are individually wound, from interlinking with the windings wound on the other middle leg part, a slit is provided between each middle leg part in the base part. interleave choke coil high magnetic resistance region is formed comprising. Interleaving choke coil according to claim 1, wherein the non-magnetic material in said slit is filled. The standing length of the middle leg is shorter than that of the outer leg, and the high magnetoresistive region is formed by a gap formed between the middle legs in a state where the opposed outer legs are in contact with each other. The choke coil for interleaving according to claim 1 or 2, further comprising: The interleave choke coil according to any one of claims 1 to 3 , wherein the middle leg portion, the base portion, and the outer leg portion are made of a single material of either a dust magnetic material or ferrite. The interleave choke coil according to any one of claims 1 to 4 , wherein the middle leg portion is made of a material having higher magnetic resistance than the base portion and the outer leg portion.

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