JP2010263078A - Reactor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small reactor excellent in productivity which can execute soft switching in addition to voltage boosting and reducing operations. <P>SOLUTION: The reactor 1A includes a magnetic core 10 having an inner core portion 10i and a coil 11 disposed on the outer circumference of the inner core portion 10i. The magnetic core 10 is a so-called E-E core. The coil 11 is equipped with a main coil portion 12 and a sub-coil portion 13 which are formed by winding different winding wires respectively, and one end of the winding of the main coil portion 12 is joined to one end of the winding of the sub-coil portion 13. The main coil portion 12 and the magnetic core 10 configure a smoothing reactor, and the sub-coil portion 13 and the magnetic core 10 configure a resonant reactor, and soft-switching can be executed. Since the common magnetic core 10 is provided between both the coil portions 12 and 13, the reactor is small, compared to a case where a resonant reactor is differently provided. The coil 11 is disposed in only an inner core portion 10i, thereby readily assembling the reactor excellent in productivity. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a reactor used for a component part of a power conversion device such as an in-vehicle DC-DC converter. In particular, the present invention relates to a reactor that is small and excellent in productivity.

  One of the components of a circuit that performs voltage boosting and voltage dropping operations is a reactor that smoothes the current generated by ON / OFF switching operations of switching elements. For example, a reactor used in a converter mounted on a vehicle such as a hybrid vehicle typically has a configuration in which a pair of coils formed by winding a coil are arranged in parallel on the outer periphery of an annular magnetic core. (Patent Document 1 FIG. 10). In addition, in Patent Document 1, a cylindrical core disposed on the inner periphery of one coil, a cylindrical core disposed so as to cover the outer periphery of the coil, and a pair of circles disposed on each end face of the coil A magnetic core having an E-shaped cross section including a plate-like core, that is, a reactor including a so-called pot-type core is disclosed (FIG. 1 of Patent Document 1). In the pot-type core, the columnar core and the cylindrical core arranged concentrically are connected by the disk-shaped core to form a magnetic path.

  In recent years, resonance type DC-DC converters capable of soft switching with less switching loss than conventional converters have been studied. The converter includes an auxiliary circuit including a resonance reactor and a resonance switching element in addition to the smoothing reactor. Patent Document 2 discloses a configuration including inductors L1 and L2, and an inductor Lr having an inductance value smaller than both inductors L1 and L2 (FIG. 1 of Patent Document 2). The inductor L1 is used as a smoothing reactor, and soft switching is realized by the inductors L2 and Lr.

JP 2007-201203 JP 2007-043852 A

  However, Patent Documents 1 and 2 do not disclose a specific structure of a reactor (inductance) capable of soft switching. For example, it is conceivable that the smoothing reactor and the resonance reactor are independent members. However, since this configuration requires a space for installing both reactors, it is not preferable for in-vehicle components that require a small installation area and a small size. Moreover, if it is a separate member, it is necessary to assemble each, and there are many number of parts and an assembly process, and it causes the fall of productivity.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a small reactor having excellent productivity while having a plurality of coils having different functions.

  The present invention achieves the above-mentioned object by adopting a configuration in which one magnetic core can be commonly used for a plurality of coils used for different functions and a magnetic core having a specific shape.

  The present invention relates to a reactor including a magnetic core and a coil disposed on a part of the magnetic core. The magnetic core includes an inner core portion, an outer core portion, and a connecting core portion. The inner core portion is disposed inside the coil, and the outer core portion is disposed outside the coil. The said connection core part is arrange | positioned at the end surface of the said coil, and typically connects the said inner core part and an outer core part. The coil includes a main coil portion and a sub coil portion. The main coil portion is formed by winding a winding and is disposed on the outer periphery of the inner core portion. The sub coil portion is formed by winding a winding different from the winding constituting the main coil portion, and is disposed on the outer periphery of the inner core portion. And the one end part of the coil | winding which comprises these main coil parts and the one end part of the coil | winding which comprises a subcoil part are joined.

  According to the above configuration, for example, the main coil portion and the magnetic core can function as a smoothing reactor, and the sub-coil portion and the same magnetic core can function as a resonance reactor. That is, according to the above configuration, soft switching can be performed in addition to the step-up operation and the step-down operation. In particular, according to the above configuration, since the main coil portion and the subcoil portion use one common magnetic core, compared to the case where the smoothing reactor and the resonance reactor are separate separate members, Small installation area and small size. And according to the said structure, since there are few parts parts compared with the case where it is another member as mentioned above, an assembly process can be reduced and it is excellent in productivity of a reactor. Moreover, according to the said structure, since a main coil part and a subcoil part are arrange | positioned only at an inner core part, compared with the case where a coil is arrange | positioned at both an inner core part and an outer core part, it is small. In addition, since only one coil is disposed in the magnetic core, an assembly of the magnetic core and the coil can be easily formed, and the productivity of the reactor is excellent. Furthermore, according to the said structure, since the said coil is not arrange | positioned, an outer core part and a connection core part are easy to discharge | release the heat | fever of a magnetic core, and are excellent also in heat dissipation. Such a reactor of the present invention is expected to be suitably used particularly when the number of turns is small and the gap provided in the magnetic core for adjusting the inductance is small.

In the present invention, examples of the arrangement of the coils include the following three forms.
(I) Laminate form: Form that is arranged concentrically so that at least a part of the sub-coil part overlaps the outer periphery of the main coil part
(II) Interleaved configuration: a configuration in which at least one turn constituting the sub-coil portion exists between turns constituting the main coil portion
(III) Vertically arranged form: Form in which the main coil part and the sub-coil part are arranged adjacent to each other without being overlapped.

  According to the above-described vertical arrangement, both the coil portions can be easily formed and can be easily assembled to the magnetic core, and the productivity of the reactor is excellent. According to the laminated form, compared with the vertically arranged form, leakage inductance (leakage) can be reduced, and the length of the reactor (the axial distance of the main coil part (or sub-coil part)) is reduced. It can be made small and it can be set as a small reactor. According to the alternate arrangement form, while the leakage inductance can be equal to or less than that of the laminated form, the width and height of the reactor than the laminated form (both the width and the height are the main coil part (or the secondary coil). Part)) in the direction perpendicular to the axial direction) can be reduced, and a small reactor can be obtained. The arrangement form of both coil portions can be selected according to desired characteristics.

  In the above laminated form, the leakage inductance can be changed by devising the interval between the turns constituting the sub-coil part and the arrangement position with respect to the main coil part. For example, the interval between adjacent turns in the sub-coil portion may be wider than the interval between adjacent turns in the main coil portion, or the axial center position of the main coil portion and the axis of the sub-coil portion If the center position in the direction is shifted in the axial direction, the leakage inductance should be reduced compared to the case where the distance between the turns of both coil parts is equal or the case where the center positions of both coil parts are equal in the axial direction. Can do. It is preferable to appropriately adjust the interval between the turns of the sub-coil portion and the arrangement position so as to obtain a desired leakage inductance.

  As one form of this invention, the inner core part has the form which has an air gap.

  By providing a gap (gap) in the inner core portion where the coil is disposed, magnetic saturation can be reduced. In particular, according to the above configuration, a gap material made of a non-magnetic material is unnecessary, and the number of parts can be reduced, and a gap material joining step can be eliminated. In order to provide the air gap, for example, the magnetic core includes a pair of connecting core portions, the inner core portion includes a pair of core pieces, one core piece is joined to one connecting core portion, and the other core piece. The size of the core piece and the outer core part is adjusted so that a predetermined gap is provided between the core pieces in a state where the two connected core parts are joined to each other by the outer core part. To do. The said clearance gap can be utilized for an air gap.

  The reactor according to the present invention can perform soft switching in addition to the step-up operation and the step-down operation, and is small in size and excellent in productivity.

FIG. 1 is a schematic cross-sectional view schematically showing a laminated reactor. FIG. 1 (I) shows an example in which the axial center position of the main coil portion is equal to the axial center position of the auxiliary coil portion. FIG. 1 (II) is an example in which the axial center position of the main coil portion is shifted from the axial center position of the sub coil portion, and FIG. 1 (III) is adjacent to the sub coil portion. An example in which the interval between turns is wider than the interval between adjacent turns constituting the main coil portion is shown. FIG. 2 is a schematic cross-sectional view schematically showing another form of reactor. FIG. 2 (I) shows an example of an alternately arranged form, and FIG. 2 (II) shows an example of a vertically arranged form.

  Hereinafter, reactors 1A, 1B, 1C, 1D, and 1E according to embodiments will be described with reference to the drawings. The same reference numerals in the figure indicate the same names. In FIGS. 1 and 2, the ends of the windings are omitted for easy understanding. In FIG. 2 (I), □ indicates the winding of the main coil portion, and ○ indicates the winding of the sub-coil portion.

  Each of the reactors 1A, 1B, 1C, 1D, and 1E includes a magnetic core 10 and a coil 11 disposed on a part of the core 10 (inner core portion 10i). Reactors 1A to 1E are characterized in that the coil 11 is composed of two coil parts (main coil part 12 and sub-coil part 13), and one magnetic core 10 is provided for the two coil parts. In common. Reactors 1A to 1E have the same configuration except that the arrangement form of the two coil portions is different. Hereinafter, each component will be described in detail with the reactor 1A as a representative. Reactors 1B to 1E will be described with a focus on the arrangement form of the two coil portions, and the description of other configurations will be omitted.

[Coil 11]
"overall structure"
The coil 11 has a main coil portion 12 formed by spirally winding one continuous winding, and one continuous winding different from the winding constituting the main coil portion 12 in a spiral shape. And a sub-coil portion 13 formed by rotation.

<Main coil section>
Here, as the winding constituting the main coil portion 12, a covered rectangular wire having an insulating coating layer made of enamel resin on the surface of a copper rectangular wire (conductor) is used. The main coil portion 12 is an edgewise coil formed by edgewise winding the covered rectangular wire. The interval between adjacent turns constituting the main coil portion 12 is narrow and is 0.5 mm or less. In the reactor 1D to be described later, the interval between adjacent turns in a portion where the sub coil portion 13 does not exist in the main coil portion 12 is 0.5 mm or less.

<Sub-coil part>
Here, as the windings constituting the sub-coil portion 13, a twisted wire conductor having a substantially circular cross section obtained by twisting a plurality of copper wires and an insulating coating layer provided on the outer periphery of the twisted wire conductor are provided. A coated electric wire having a conductor cross-sectional area smaller than that of the covered rectangular wire constituting the main coil portion 12 is used. Examples of the insulating coating layer of the covered electric wire include tetrafluoroethylene-hexafluoropropylene copolymer (FEP) resin, polytetrafluoroethylene (PTFE) resin, and silicon rubber. Here, the number of turns (number of turns) of the sub-coil portion 13 is smaller than that of the main coil portion 12.

  In the reactor 1A, the interval between adjacent turns constituting the sub-coil portion 13 is made equal to the interval between adjacent turns constituting the main coil portion 12. Therefore, the axial length of the sub-coil portion 13 is shorter than the axial length of the main coil portion 12. The same applies to reactors 1B and 1E.

  In any of reactors 1A to 1E, the thickness and width of the windings constituting each coil portion, the conductor cross-sectional area, the number of turns, and the like can be selected as appropriate.

<< Arrangement of both coil parts >>
<Reactor 1A>
In reactor 1A shown in FIG. 1 (I), sub-coil portion 13 is concentrically arranged on the outer periphery of main coil portion 12. That is, the main coil portion 12 is disposed on the inner side, and the sub-coil portion 13 is disposed on the outer side to constitute one coil 11. Here, the coil portions 12 and 13 are overlapped so that the axial center position of the main coil portion 12 and the axial center position of the sub-coil portion 13 are equal. Accordingly, the entire subcoil portion 13 overlaps the main coil portion 12, and the number of turns of the subcoil portion 13 is smaller than that of the main coil portion 12 as described above, so that the end surfaces of both the coil portions 12, 13 are aligned. It is not in the axial direction of the coil 11.

<Reactor 1B>
Similarly to reactor 1A, reactor 1B shown in FIG. 1 (II) also has sub-coil portion 13 arranged concentrically on the outer periphery of main coil portion 12. However, the arrangement position of the sub-coil part 13 is different from the reactor 1A. Specifically, the coil portions 12 and 13 are overlapped so that the axial center position of the main coil portion 12 and the axial center position of the sub-coil portion 13 are different. Here, both the coil portions 12 and 13 are arranged so that the entire sub-coil portion 13 overlaps the main coil portion 12 and one end face of both the coil portions 12 and 13 is aligned.

<Reactor 1C>
A reactor 1C shown in FIG. 1 (III) also has a sub-coil portion 13 arranged concentrically on the outer periphery of the main coil portion 12 in the same manner as the reactor 1A. However, the shape of the auxiliary coil portion 13 is different from that of the reactor 1A. Specifically, the interval between adjacent turns constituting the sub-coil portion 13 is wider than the interval between adjacent turns constituting the main coil portion 12. Here, the interval between the turns of the sub-coil portion 13 is widened so that the axial length of the sub-coil portion 13 is substantially equal to the axial length of the main coil portion 12.

  These laminated reactors 1A, 1B, and 1C use a covered electric wire that is more insulative than a covered rectangular wire as the winding of the sub-coil portion 13, so that the space between the main coil portion 12 and the sub-coil portion 13 can be reduced. Increases insulation.

<Reactor 1D>
Reactor 1D shown in FIG. 2 (I) is configured such that a winding of each turn constituting main coil portion 12 and a winding of each turn constituting sub-coil portion 13 are alternately arranged one by one. Each turn constituting the auxiliary coil portion 13 is interposed between the turns constituting 12. Accordingly, the coil portions 12 and 13 of the reactor 1D are arranged on the outer periphery of the inner core portion 10i so that the respective axial directions overlap on a straight line. Here, since the number of turns of the sub-coil portion 13 is smaller than that of the main coil portion 12, the sub-coil portion 13 exists only in a part of the main coil portion 12.

<Reactor 1E>
In a reactor 1E shown in FIG. 2 (II), a main coil portion 12 and a sub coil portion 13 are arranged coaxially adjacent to each other in the axial direction of the main coil 12. That is, the coil portions 12 and 13 of the reactor 1E are arranged on the outer periphery of the inner core portion 10i in a vertically aligned state without overlapping, and the axial directions of both the coil portions 12 and 13 are aligned on a straight line.

<< End of both coil parts >>
Both end portions of the winding constituting the main coil portion 12 and both end portions of the winding constituting the sub coil portion 13 are appropriately extended. Then, one end of the winding constituting the main coil portion 12 and one end of the winding constituting the sub-coil portion 13 are joined. Specifically, the conductors are joined by peeling off the insulating coating layer at each end. For this joining, for example, welding such as TIG welding, laser welding, resistance welding, or the like, crimping, cold welding, or vibration welding can be suitably used. Here, TIG welding is used.

  One terminal member (not shown) is connected to the joined one end. Further, the terminal member is joined to the other end of the winding constituting the main coil portion 12 and the other end of the winding constituting the sub-coil portion 13, respectively. In addition to welding such as TIG welding, crimping or the like can be used for attaching the terminal member. An external device (not shown) such as a power source for supplying power is connected to the coil portions 12 and 13 through these terminal members.

[Magnetic core 10]
The magnetic core 10 is disposed on the inner periphery of the coil 11 (in the reactors 1A, 1B, and 1C, the inner periphery of the main coil unit 12, and in the reactors 1D and 1E, the inner periphery of the main coil unit 12 and the subcoil unit 13). A columnar inner core portion 10i and a pair disposed on the outer periphery of the coil 11 (in the reactors 1A, 1B, and 1C, mainly the outer periphery of the subcoil portion 13, and in the reactors 1D and 1E, the outer periphery of the main coil portion 12 and the subcoil portion 13). The outer cylindrical portion 10o of the prism and both end surfaces of the coil 11 (reactors 1A, 1B, 1C, and 1D mainly include both end surfaces of the main coil portion 12, and the reactor 1E includes one end surface of the main coil portion 12 and the auxiliary coil portion 13). And a pair of prismatic connecting core portions 10c respectively disposed on one end face).

  Here, the inner core portion 10i and the outer core portions 10o are each divided in the axial direction of the coil 11, the inner core portion 10i includes a pair of inner core pieces 100i, and each outer core portion 10o has a pair of It has an outer core piece 100o. And, in one connecting core portion 10c, one inner core piece 100i, one outer core piece 100o of one outer core portion 10o, and one outer core piece 100o of the other outer core piece 10o, a total of three The core pieces are connected to form one E-shaped core piece (E-shaped core piece 10E). The magnetic core 10 includes a pair of the E-shaped core pieces 10E, and each outer core piece 100o of one E-shaped core piece 10E and each outer core piece 100o of the other E-shaped core piece 10E are joined by an adhesive or the like. Configured. In a state where the outer core pieces 100o are joined to each other, the inner core piece 100 so that a predetermined gap 10g is provided between the inner core pieces 100i (so that the main coil portion 12 and the subcoil portion 13 have a desired inductance). The sizes of 100i and the outer core piece 100o are adjusted. Therefore, the inner core portion 10i is composed of a pair of inner core pieces 100i and a gap 10g.

  The inner core piece 100i, the outer core piece 100o, and the connecting core portion 10c are made of a soft magnetic material containing iron, such as iron or steel, typically, a compacted body of soft magnetic powder, or a plurality of The laminated body which laminated | stacked the electromagnetic steel plate of this can be utilized. The gap 10g of the inner core portion 10i is provided for adjusting the inductance. Here, this gap 10g is used as an air gap.

[Arrangement of coil 11 with respect to magnetic core 10]
In the reactors 1A, 1B, 1C, 1D, and 1E, a coil 11 including a main coil portion 12 and a subcoil portion 13 is disposed on the outer periphery of the inner core portion 10i, and a pair of outer cores are sandwiched between the coils 11. Part 10o exists. Further, the connecting core portion 10c is present so as to cover both end faces of the coil 11. Therefore, in the reactors 1A to 1E, a part of the coil 11 is not covered with the magnetic core 10 but is exposed.

[Other components]
Bobbin
When a bobbin (not shown) made of an insulating material is provided on the outer periphery of the inner core portion 10i, the insulation between the inner core portion 10i and the coil 11 can be enhanced. An example of the bobbin is a cylindrical body that covers the outer periphery of the inner core portion 10i. Further, when a bobbin having an annular flange portion extending outward from both edges of the cylindrical body is used, the insulation between the end face of the coil 11 and the connecting core portion 10c can be enhanced. As the insulating material, an insulating resin such as polyphenylene sulfide (PPS) resin, liquid crystal polymer (LCP), or polytetrafluoroethylene (PTFE) resin can be used. In addition, in the laminated reactors 1A, 1B, and 1C, if a cylindrical bobbin is similarly provided between the main coil portion 12 and the subcoil portion 13, the insulation between the coil portions 12 and 13 is enhanced. It is done. In particular, if the cylindrical bobbin is provided with a positioning portion for the sub-coil portion 13, the sub-coil portion 13 can be easily positioned and held. In the vertically arranged reactor 1E, if a frame-like bobbin is provided between the main coil portion 12 and the sub-coil portion 13, the insulation between the coil portions 12 and 13 can be improved. In addition, an insulating paper or an insulating sheet may be interposed between the coil portions 12 and 13.

"Case"
The reactors 1A, 1B, 1C, 1D, and 1E including the magnetic core 10 and the coil 11 can be used as they are. Furthermore, for example, a combination of the magnetic core 10 and the coil 11 is housed in a metal case (not shown) such as aluminum, and a reactor filled with an insulating resin (potting resin) not shown in the case is used. Can do.

《Outside resin part》
Alternatively, without using a case, a combination of the magnetic core 10 and the coil 11 may be covered with an insulating resin, and a reactor including an outer resin portion (not shown) may be used. As the insulating resin, epoxy resin, urethane resin, PPS resin, polybutylene terephthalate (PBT) resin, acrylonitrile-butadiene-styrene (ABS) resin, or the like can be used. By omitting the case, the reactor can be made smaller. Moreover, when it is set as the structure which exposed a part of magnetic core and a part of coil from the outer side resin part, it is easy to discharge | release the heat | fever of a magnetic core or a coil, and heat dissipation is improved. Further, in the configuration in which the case is omitted and the outer resin portion is provided, the end of the winding can be easily pulled out to an arbitrary location, and the degree of freedom in designing the location where the terminal member is connected can be increased.

  Note that both end portions of both the coil portions 12 and 13 are exposed from the potting resin or the outer resin portion so that the terminal member can be attached. By storing in a case or having an outer resin part, the magnetic core 10 and the coil 11 can be protected from the external environment such as dust and corrosion, mechanically protected, and the assembly can be handled integrally. . In addition, in the reactors 1A and 1B, the placement position of the sub-coil portion 13 is maintained by the potting resin or the outer resin portion, or in the reactor 1C, the resin is interposed between adjacent turns of the sub-coil portion 13. A predetermined interval can be maintained.

[Assembly of the reactor]
The stacked reactors 1A, 1B, and 1C can be formed as follows.

  First, a combined coil body in which the main coil portion 12 and the sub coil portion 13 are arranged concentrically in order on the outer periphery of the bobbin made of the insulating material described above is formed. Specifically, the main coil portion 12 is formed by using the bobbin as a winding drum, and the sub coil portion 13 is formed at a predetermined position on the outer periphery of the main coil portion 12, or a sub coil portion that is separately manufactured. Assemble 13. The position of the subcoil portion 13 may be adjusted as appropriate by moving the subcoil portion 13 so that the axial center positions of the main coil portion 12 are aligned. Then, the inner core piece 100i of one E-shaped core piece 10E is inserted into one opening of the bobbin having the combined coil body, and the inner side of the other E-shaped core piece 10E is inserted into the other opening of the bobbin. The core piece 100i is inserted, and the outer core pieces 100o of both E-shaped core pieces 10E are joined with an adhesive or the like. By this joining, a predetermined gap 10g is provided between the inner core pieces 100i. By the above process, reactors 1A, 1B, and 1C are obtained.

  When assembling the sub-coil portion 13 on the outer periphery of the main coil portion 12, at least one end of the winding of the main coil portion 12 is extended in the axial direction of the main coil portion 12, for example, on the outer periphery of the turn of the main coil portion 12. If it does not protrude, it does not get in the way when the sub-coil portion 13 is assembled. Then, after the sub-coil portion 13 is assembled, the end of the winding of the main coil portion 12 may be appropriately bent so that the terminal member can be easily attached and connected to the sub-coil portion. Alternatively, when the subcoil portion 13 is assembled to the outer periphery of the main coil portion 12, the subcoil portion 13 may be slightly deformed and assembled, and then the subcoil portion 13 may be reshaped to form a concentric combination coil body. Good. A concentric combination coil body in which the sub coil section 13 is assembled on the outer periphery of the main coil section 12 may be manufactured, and the bobbin may be disposed inside the combination coil body. In this case, the bobbin is easy to be arranged when a pair of half crack pieces are combined to form a cylindrical shape. Also in the formation of reactors 1D and 1E described later, a bobbin may be inserted after the combined coil body is manufactured. In addition, a concentric combined coil body in which the sub-coil portion 13 is assembled to the outer periphery of the main coil portion 12 is manufactured, and the outer periphery of the combined coil body is covered with resin, and the shape of the combined coil body is maintained by this resin. When the coil molded body is used, it is easy to handle the combined coil body when assembled with the magnetic core, and the above-described bobbin and the like can be omitted. Similarly, reactors 1D and 1E, which will be described later, can be formed as coiled bodies.

  When forming the alternately arranged reactors 1D, if the combined coil body is prepared in advance, it is easy to assemble with the magnetic core 10 as in the above-described laminated form. For example, after the main coil portion 12 is formed on the outer periphery of the bobbin as described above, the combination coil body is formed by winding the windings constituting the sub-coil portion 13 between the turns of the main coil portion 12. It is obtained by making the turn of the sub-coil part 13 exist between the turns. At this time, if the space between the turns of the main coil portion 12 is widened (it may be a state in which the main coil portion 12 is naturally widened by springback), the winding of the sub-coil portion 13 can be easily wound. Alternatively, the combined coil body can be obtained by simultaneously winding the winding constituting the main coil portion 12 and the winding constituting the sub-coil portion 13. When winding at the same time, since the number of turns of the sub-coil portion is smaller than that of the main coil portion, a step of forming only the main coil portion in the middle is included. Reactor 1D is obtained by inserting and arranging the inner core portions 10i of both E-shaped core pieces 10E in the bobbin having the obtained combined coil body and assembling the magnetic core 10 in the same manner as in the above-described laminated form. It is done.

  When forming the reactors 1E in a vertically arranged form, both the E-cores are formed on the bobbin having both the coil portions 12 and 13 by producing the main coil portion 12 and the subcoil portion 13 on the outer periphery of the bobbin as described above. The inner core portion 10i of the piece 10E is inserted and arranged, and the magnetic core 10 is assembled in the same manner as in the above laminated form.

  Note that the end portions of the coil portions 12 and 13 can be joined to each other at any time, either before assembly to the magnetic core 10 or after assembly of the combination of the magnetic core 10 and the coil 11.

  The obtained combination of the magnetic core 10 and the coil 11 may be housed in a case and filled with a potting resin, or may be covered with an outer resin portion.

[effect]
When all reactors 1A, 1B, 1C, 1D, and 1E are assembled as components of a bidirectional DC-DC converter, the main coil unit 12 and the magnetic core 10 can perform step-up and step-down operations, and the subcoil Since the part 13 and the magnetic core 10 can perform soft switching in the above operation, loss due to the switching operation can be reduced. In particular, in each of the reactors 1A to 1E, when the number of turns of both the coil portions 12 and 13 is small and the gap 10g provided in the magnetic core 10 may be small, for example, the current frequency during use is high, and the inductance value Can be suitably used when the value is small. In addition, all of the reactors 1A to 1E are smaller than the case where a resonance reactor is separately provided by using the magnetic core 10 in common for the main coil portion 12 and the subcoil portion 13. .

  In particular, in the reactors 1A, 1B, and 1C in the laminated form in which the sub-coil portion 13 is concentrically arranged on the outer periphery of the main coil portion 12, the axial length of the sub-coil portion 13 is the same as the axial length of the main coil portion 12. It is below the length. Therefore, it is not necessary to change the length of the inner core portion 10i (the length of the main coil portion in the axial direction (left-right direction in FIG. 1)) by adding the sub-coil portion 13 to the main coil portion 12 (dimensions). There is little increase). Also from this point, reactors 1A, 1B, and 1C are small. On the other hand, reactors 1D and 1E both have a smaller width and height of the reactor (both the width and height are distances in the direction perpendicular to the axial direction of main coil portion 12) than in the above-described stacked configuration. Can be small. In addition, the reactors 1A, 1B, 1C, 1D, and 1E all have an increased space factor because the main coil portion 12 is formed of a covered rectangular wire. From this point as well, the length of the inner core portion 10i is increased. It can be shortened and is small.

  The reactors 1A, 1B, 1C, 1D, and 1E all use the magnetic core 10 that includes the inner core portion 10i, the outer core portion 10o, and the connecting core portion 10c, and the main coil portion 12 described above. In addition, since the auxiliary coil portion 13 is disposed only at one location on the inner core portion 10i, the assembly operation of the magnetic core 10 and the coil 11 is easy, and the productivity is excellent. In particular, in each of the reactors 1A to 1E, the main coil part 12 is configured by a covered rectangular wire, so that it is easy to take a wide contact area when joining one end parts of both the coil parts 12 and 13, and the joining work is performed. Since it is easy to perform, it is excellent also in productivity from this point.

  In addition, the reactors 1A, 1B, 1C, 1D, and 1E all have one end of the coil portions 12 and 13 joined directly by welding and share one terminal member. (Here, a configuration including a total of three terminal members), the number of parts can be reduced, and the number of steps for attaching the terminal members can be reduced. Also from this point, the reactors 1A to 1E are excellent in productivity. A terminal member is attached to each end portion of the main coil portion and each end portion of the sub coil portion, and one end portion of the winding of the main coil portion and one end portion of the winding of the sub coil portion are connected to the terminal member. It is possible to adopt a configuration in which a total of four terminal members are provided. Even if the types of windings constituting both coil parts are different as in reactors 1A to 1E, it is possible to easily join both coil parts by attaching terminal members and using bolts etc. it can. Further, each of the reactors 1A to 1E has a single gap 10g provided for adjusting the inductance, and this gap 10g serves as an air gap, and no gap material is used. Therefore, it is possible to reduce the number of parts and the attachment process of the gap material. From this point, the reactors 1A to 1E are excellent in productivity. In addition, the reactors 1E in the vertically arranged form are easy to form the coil 11 including both the coil parts 12 and 13 as compared with the laminated form and the alternately arranged form, and are excellent in productivity.

  In addition, the reactors 1A, 1B, 1C, 1D, and 1E are all exposed without being covered with the magnetic core 10, so that the heat of the coil 11 is easily released and the heat dissipation is excellent.

(Modification 1)
In the above-described embodiment, the form in which both coil portions are configured from different types of windings has been described. In addition, it is good also considering the coil | winding which comprises both coil parts as the same kind of coil | winding. That is, the windings constituting both coil portions may be covered rectangular wires or covered electric wires. In addition, as other windings, a coated round wire having a conductor made of a round wire and an insulating coating layer made of enamel resin or the like on the outer periphery of the conductor, a deformed wire having a polygonal cross section, or a foil shape Various wires such as a sheet wire having an insulating coating layer on the surface of the conductor can be used. The covered round wire is easy to bend like a covered electric wire, and can easily form a coil in a laminated form or an alternately arranged form.

  In a form in which both coil portions are formed of coated rectangular wires, a sufficient contact area can be ensured when joining one end portions of both coil portions, and the joining strength can be increased. In addition, when the secondary coil is used for a resonance reactor, the current flowing in the secondary coil is smaller than the current flowing in the coil of the smoothing reactor. A winding with a low rate can be used. Therefore, when the width of the flat wire constituting the sub-coil portion is the same as the width of the flat wire constituting the main coil portion, the flat wire constituting the sub-coil portion is thinner than the main coil portion. Can be used. By using a rectangular wire with a small thickness, the length of the auxiliary coil portion in the axial direction can be shortened. Therefore, especially in the alternately arranged form and the vertically arranged form, the length of the inner core part can be shortened, and the reactor can be made small.

  Further, in the laminated form, when the secondary coil portion arranged outside is formed of a covered rectangular wire, if the flat-wise coil is not a edgewise coil but a flatwise coil that is wound flatwise, The size (width and height) in the direction orthogonal to the axial direction of the coil portion can be reduced. Therefore, it can be set as a small reactor. Alternatively, in the laminated form, if the sub-coil portion disposed on the outside is formed of a sheet-like wire, it can be a small reactor as in the case of the flatwise coil. Even when a flatwise coil or sheet-like wire is used, the number of turns in the subcoil part is smaller than that in the main coil part, so that the axial length of the subcoil part is not excessively long and the reactor is made compact. Can be.

  Further, as described above, a winding having a low electrical conductivity of the conductor, for example, a conductor made of aluminum or an aluminum alloy can be used as the winding constituting the sub-coil portion. Aluminum and aluminum alloys are lighter in weight, although they have lower electrical conductivity than copper and copper alloys, and can contribute to reducing the weight of the reactor.

(Modification 2)
In the above-described embodiment, the form including the air gap has been described. Instead of the air gap, a gap material made of a nonmagnetic material such as alumina may be appropriately arranged in the gap 10g between the inner core pieces 100i. The gap material and the inner core piece may be fixed with an adhesive or the like. Moreover, it is good also as a structure which comprises an inner core part from more core pieces, and is provided with the gap material and the air gap suitably between each core piece, and is set as the inner core part of the laminated structure. Furthermore, it is good also as a form which provides an air gap and a gap material not in an inner core part but in an outer core part. Also, one outer core part is a solid member that does not have an air gap (may include a gap material), and both the inner core part and the other outer core part have an air gap or gap material. It is good. The form of the inner core part and the outer core part can be appropriately selected so that the main coil part 12 and the sub coil part 13 have desired inductances.

(Modification 3)
In the above-described embodiment, a form (so-called EE core) including a pair of E-shaped core pieces 10E as a magnetic core has been described. Separation of the inner core portion and the outer core portion can be appropriately selected. For example, the inner core portion is a magnetic member, the inner core portion and the outer core portion are connected to one connecting core portion, and the other connecting core portion is an independent member (so-called EI core), the inner core The T-shaped core piece and the T-shaped core piece in which only the inner core part is connected to one connecting core part and only the outer core part is connected to the other connecting core part. Form, the inner core portion is configured to include a pair of inner core pieces, only one inner core piece is connected to one connecting core portion, and the outer core portion and the other inner core piece are connected to the other connecting core portion. The TE shape of the T-shaped core piece and the E-shaped core piece, the inner core portion is one magnetic member, and one outer core piece constituting the inner core portion and each outer core portion is connected to one connected core portion The other outer core piece constituting each outer core portion is connected to the other connected core portion. E-form of E-shaped core piece and] -shaped core piece. In the above-described EI form and T-] form, the length of the inner core part (only the part made of a magnetic material) is made shorter than the length of the outer core part, so that a predetermined distance is provided between the inner core part and the connecting core part. This gap can be used as an air gap. In the TE mode, the length of the outer core portion may be adjusted so that a predetermined gap is provided between the inner core pieces when the magnetic core is assembled.

  In addition, it is possible to use a form in which the outer core portion is cylindrical and covers almost the entire outer periphery of the coil, that is, a cross-sectional EE form, a so-called pot-type core.

(Modification 4)
In the reactor 1D of the alternately arranged form shown in FIG. 2 (I), both ends of the combined coil body in which the main coil portion 12 and the sub coil portion 13 are combined are windings constituting the main coil portion 12. In addition, one end or both ends of the combination coil body may be a winding constituting the sub coil portion. In addition, if the windings of the turns constituting the two coil portions are not arranged one by one, but in a form in which a plurality of turns are alternately arranged, the sub coil portion can have a portion with a wide interval between turns, Like the reactor 1C described above, the leakage inductance can be reduced. The number of turns of the main coil portion existing between the turns of the sub coil portion may be equal or different.

  Alternatively, the main coil portion may be constituted by a pair of divided coils divided in two in the axial direction, and the sub coil portion may be sandwiched between these divided coils. In this form, since the subcoil part is grouped, it is easy to form a combined coil body as in the case of the vertically arranged form. The joint location between the pair of split coils may be arranged so as to straddle the sub-coil portion sandwiched between the split coils. The split coils can be joined to each other at any time, but if the sub coil portions are arranged between the two split coils, the sub coil portions are easily arranged. In this embodiment, the turns constituting the main coil portion include those formed by joining the windings as described above.

(Modification 5)
Leakage magnetic flux based on one of the coil parts 12 and 13 by adjusting the gap (distance in the axial direction of the coil) between the coil parts 12 and 13 in the vertically arranged form as shown in FIG. A predetermined leakage inductance defined by is obtained. When this leakage inductance is used for the soft switching inductor Lr, the separate inductor Lr is unnecessary, and the number of components can be reduced.

[Test example]
The leakage inductance when the arrangement of the main coil portion and the sub coil portion was changed was obtained by simulation.

  In this test, a reactor 1A (stacked form) in FIG. 1 (I), a reactor 1D (alternately arranged form) shown in FIG. 2 (I), and a reactor 1E (vertically arranged form) shown in FIG. Each leakage inductance was determined. In any of the forms, the main coil portion is a covered rectangular wire, the sub coil portion is a covered electric wire, the sub coil portion is 10 turns, and the main coil portion is 60 turns. In the alternately arranged reactor 1D, the first 10 turns out of the 60 turns of the main coil portion were alternately arranged with the turns of the sub coil portion. In the vertically arranged reactor 1E, both coil portions are arranged vertically with a coupling coefficient of 0.9. In this test, substantially the same magnetic core was used.

  Then, the leakage inductance was obtained when a current of 1 A was passed through only the main coil portion with the sub coil portion short-circuited. The results are shown in Table 1.

  As shown in Table 1, it can be seen that the magnitude of the leakage inductance can be changed by changing the arrangement of the two coil portions. In order to obtain a reactor having a desired leakage inductance, the arrangement form, the interval between turns, the arrangement position of both coil portions, and the like may be appropriately selected and adjusted.

  The above-described embodiment can be appropriately changed without departing from the gist of the present invention, and is not limited to the above-described configuration.

  The reactor of the present invention can be used as a component of a power conversion device such as a bidirectional soft switching DC-DC converter mounted on a vehicle such as a hybrid vehicle, an electric vehicle, or a fuel cell vehicle.

1A, 1B, 1C, 1D, 1E reactor
10 Magnetic core 10E E core piece 10i Inner core 10o Outer core
10c Linking core 10g Clearance 100i Inner core piece 100o Outer core piece
11 Coil 12 Main coil 13 Sub coil

Claims (8)

A reactor comprising a magnetic core and a coil disposed on a part of the magnetic core,
The magnetic core is
An inner core disposed inside the coil;
An outer core portion disposed outside the coil;
A connecting core portion disposed on an end face of the coil,
The coil is
A main coil portion formed by winding a winding and disposed on the outer periphery of the inner core portion;
A winding different from the winding constituting the main coil portion is wound, and comprises a sub-coil portion arranged on the outer periphery of the inner core portion,
A reactor, wherein one end portion of a winding constituting the main coil portion and one end portion of a winding constituting the sub coil portion are joined.   2. The reactor according to claim 1, wherein at least one turn constituting the sub-coil portion exists between turns constituting the main coil portion.   2. The reactor according to claim 1, wherein the reactor is arranged concentrically so that at least a part of the sub-coil portion overlaps with an outer periphery of the main coil portion.   2. The reactor according to claim 1, wherein the main coil portion and the sub coil portion are arranged adjacent to each other without being overlapped with each other.   4. The reactor according to claim 3, wherein an interval between adjacent turns in the sub coil portion is wider than an interval between adjacent turns in the main coil portion.   6. The reactor according to claim 3, wherein an axial center position of the main coil portion and an axial center position of the sub coil portion are shifted in the axial direction.   The reactor according to any one of claims 1 to 6, wherein the inner core portion has an air gap. The reactor is a component of a bidirectional soft switching converter,
The main coil unit is used for at least one of a step-up operation and a step-down operation,
The reactor according to any one of claims 1 to 7, wherein the sub-coil portion is used for soft switching.

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