JP2012023079A - Reactor - Google Patents

Abstract

A reactor capable of effectively suppressing eddy current loss due to leakage magnetic flux with a simple configuration is provided.
A reactor includes two U-shaped or U-shaped core members 16 having two leg portions 18, and end faces 20 of the leg portions 18 of the core member 16 are opposed to each other with a predetermined gap therebetween. Reactor cores 12 arranged and arranged, and two coils 14 wound around the legs 18 of the core members 16 facing each other with a gap 24 therebetween. The end face side portion 54 of the leg portion 18 facing the inner peripheral side of the annular reactor core 12 is largely subjected to a corner dropping process as compared with the end face side portion 56 of the leg portion 18 facing the outer peripheral side of the reactor core 12.
[Selection] Figure 2

Description

  The present invention relates to a reactor, and more particularly, a reactor core formed by annularly connecting two U-shaped or U-shaped core members via a gap, and windings around the legs of each core member including the gap. It is related with a reactor provided with two coils rotated.

  Conventionally, a reactor has been used as a boost converter component for boosting a DC voltage. This reactor generally includes a reactor core in which a plurality of core members made of a magnetic material are bonded and connected in a ring shape through a nonmagnetic gap plate, and a coil wound around the connecting portion of the core member. Composed. In such a reactor, the electric energy flowing through the coil can be temporarily stored in the reactor core as magnetic energy.

  In the reactor, when the coil is energized and the reactor core is excited, leakage magnetic flux is likely to occur at the connecting portion of the core member. This leakage magnetic flux flows from the end of one core member to the end of the other core member so as to go around the outer periphery of the nonmagnetic gap plate. When such a leakage magnetic flux is linked to a coil wound around the eddy current, an eddy current is generated in the coil, and an eddy current loss is generated.

  In order to reduce the eddy current loss, for example, in Japanese Patent Application Laid-Open No. 2008-210998 (Patent Document 1), a coil wound around a central magnetic leg (12, 12) opposed via an air gap (9) Is divided into a divided copper material 1 and a divided copper material 2, and a reactor element with an air gap is described in which a dividing point (15) which is a space portion is provided between the divided copper material 1 and the divided copper material 2. Yes.

  In addition, JP 2009-32922 A (Patent Document 2) describes a plurality of magnetic core materials (1, 2) and non-magnetic material interposed between adjacent core materials (1, 2). A gap plate (3) having a gap plate (3), wherein a facing surface of the core material (1, 2) and a facing surface of the gap plate (3) are fixed via an adhesive layer (4). Forming a leakage flux attracting and transmitting means (6) for attracting the leakage flux leaked from the core material and flowing the leakage flux to the adjacent core material on the peripheral surface other than the opposite surface of As the attracting transmission means (6), an endless protrusion of ferromagnetic material is illustrated.

JP 2008-210998A JP 2009-32922 A

  As described in Patent Document 1, when the coil wound around the central magnetic legs facing each other through the air gap is divided into two, a structure in which the divided coils are electrically connected to each other, There is a problem that a structure for individually supporting the central magnetic leg is required and the structure becomes complicated.

  In the reactor core, a leakage magnetic flux in which a ripple component is superimposed on a direct current component is generated. However, as described in Patent Document 2, the leakage magnetic flux attracting and transmitting means made of a ferromagnetic material draws the leakage magnetic flux to an adjacent core member. Since the magnetic shield cannot separate the leakage flux for each frequency component, it is necessary to take measures against all the leakage flux including the DC component. For this reason, if effective magnetic shielding is applied to all leakage flux, the structure of the magnetic shield becomes larger and the reactor core itself becomes larger. The linearity of the DC superposition characteristics of the reactor is reduced due to the non-linear magnetic characteristics of the magnetic shield. In addition, there is a problem that the structure of the gap plate becomes complicated.

  An object of the present invention is to provide a reactor that can effectively suppress eddy current loss due to leakage magnetic flux with a simple configuration.

  The reactor according to the present invention includes two U-shaped or U-shaped core members having two leg portions, and the end surfaces of the leg portions of the core member are arranged to face each other via a gap. An annular reactor core and two coils wound around the legs of the core members facing each other through the gap, the inner circumference side of the annular reactor core ( The end face side part of the leg part facing the window inner side is subjected to a large angle drop process compared to the end face side part of the leg part facing the outer peripheral side (window outer side) of the reactor core.

  In the reactor according to the present invention, the corner dropping process is performed so that the gap between the end surfaces of the leg portions of the core member increases as the gap approaches the inner peripheral side in the width direction of the leg portions. It may be carried out by forming an end face side part on the inner peripheral side of the part.

  Further, in the reactor according to the present invention, in the corner dropping process, the end surface side portion on the inner peripheral side of the leg portion of the core member is formed as a curved surface, or the side portion is formed as a corner dropping plane. Also good.

  Further, in the reactor according to the present invention, from the start position on the end face where the corner dropping process is performed on the end face side part of the leg part facing the inner peripheral side to the inner peripheral side face of the leg part of the core member May be 15 to 40% with respect to the full width of the leg portion of the core member.

  Further, in the reactor according to the present invention, the core member has a rectangular cross-sectional shape and a leg end face shape, and the inner peripheral side surface of the leg portion facing the inner peripheral side of the annular reactor core and the coil The coil is formed so that the distance between the inner peripheral portion and the inner peripheral portion is constant over the entire length of the coil, while the outer peripheral side surface of the leg portion facing the outer peripheral side of the annular reactor core and the inner periphery of the coil The distance in the vicinity of the gap may be larger than the fixed dimension at both ends of the coil.

  In this case, for at least one of the distances between the first and second side surfaces of the leg portion of the core member excluding the inner peripheral side surface and the outer peripheral side surface and the inner peripheral portion of the coil, The dimension in the vicinity of the gap may be formed larger than the certain dimension at both ends of the coil.

  In this case, the coil portion having a large distance may be formed to have a length 3 to 6 times the dimension of the gap, with the center position between the gaps as the axis of symmetry.

  In this case, the distance has a maximum dimension at a position corresponding to the gap, and the maximum dimension may be 20% or more larger than the minimum dimension that is the distance at both ends of the coil.

  Further, in this case, the coil portion having a large distance is formed to have a length of 3 to 6 times the dimension of the gap with the center position between the gaps as the axis of symmetry. The distance may gradually increase or decrease between a minimum dimension and a maximum dimension in a distance change area corresponding to less than or equal to%, and the distance may be set to the maximum dimension outside the distance change area.

  In the reactor according to the present invention, with respect to the core member, the end face side portion of the leg portion facing the inner peripheral side of the annular reactor core is largely cut off compared to the end face side portion of the leg portion facing the outer peripheral side of the reactor core. Has been processed. Thereby, on the inner peripheral side of the reactor core, the gap between the leg end faces facing each other is formed larger than that on the outer peripheral side, and the magnetic resistance becomes relatively large. As a result, it is possible to reduce the amount of leakage magnetic flux from the core member in the enlarged gap portion and to suppress the leakage magnetic flux from bulging inward of the annular reactor core. Therefore, the amount of leakage flux linkage passing through the coil on the inner peripheral side of the reactor core can be reduced, and thereby eddy current loss can be effectively reduced.

  Thus, according to the reactor according to the present invention, it is generated in the coil with a simple configuration in which the inner peripheral side portion of the leg portion of the core member is subjected to a relatively large angle reduction process without performing coil division or magnetic shielding. Eddy current loss can be effectively suppressed.

  Further, the outer peripheral side of the end face of the core member is relatively small, or the magnetic path area is ensured by eliminating the corner-dropping process, and thereby the inductance of the reactor core with respect to the direct current supplied to the coil. The linearity of can be maintained.

It is a top view of the reactor which is one embodiment (henceforth embodiment) of this invention. FIG. 2 is a partial cross-sectional view (a bobbin is omitted) of the reactor shown in FIG. 1. It is a top view of a bobbin. It is the A section enlarged view in FIG. It is the B section enlarged view in FIG. It is CC sectional view taken on the line in FIG. 2 (a core end surface is included). It is a figure similar to FIG. 5 which shows the inner peripheral side part of the leg part of the core member which carried out the corner dropping process by the corner dropping plane. It is a figure which shows the confirmation result of the eddy current loss reduction of the reactor of this embodiment in comparison with a prior art example. It is a figure similar to FIG. 2 which shows the reactor which is another embodiment of this invention.

  Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In this description, specific shapes, materials, numerical values, directions, and the like are examples for facilitating the understanding of the present invention, and can be appropriately changed according to the application, purpose, specification, and the like.

  FIG. 1 shows an upper surface of a reactor 10 according to an embodiment of the present invention, and FIG. 2 shows a part of a cross section taken along a plane parallel to the upper surface of the reactor 10 of FIG. In FIG. 2, the bobbin 26 is not shown.

  The reactor 10 includes a reactor core 12 and two coils. The reactor core 12 is composed of two core members 16 having a substantially U-shaped or U-shaped upper surface shape. The core member 16 has two leg portions 18 and 18 projecting in parallel. When the core member 16 is viewed from the arrow X direction, the end surface 20 of each leg 18 is formed in a rectangular shape typified by a rectangle or a square. The core member 16 has a rectangular cross section that is the same as or similar to the end face 20 from the end face of one leg 18 to the end face of the other leg 18.

  The core member 16 is made of a magnetic material having magnetic properties with high linearity, and is composed of a sintered magnetic core, a dust core, a laminate of electromagnetic steel sheets, and the like. When the core member 16 is composed of a laminated body of electromagnetic steel plates such as silicon steel plates, for example, a plurality of electromagnetic steel plates punched into a substantially U shape are stacked and fixed together by a fastening method such as welding, bonding, or caulking. Alternatively, a belt-shaped electromagnetic steel sheet is wound a predetermined number of times around a winding mold having an outer shape substantially corresponding to the window 22 formed in the center of the reactor core 12, and the end is welded to the outer periphery of the wound body, etc. Each core member 16 may be formed by fixing with the above, removing the wound body from the winding mold, and dividing it into two. Hereinafter, regarding the core member 16 constituting the annular reactor core 12, the inner side facing the window portion 22 is referred to as an inner periphery or inner peripheral side, and the opposite outer side is referred to as an outer periphery or outer peripheral side.

  The two core members 16 are arranged so that the end surfaces 20 of the respective leg portions 18 face each other via gaps 24 having a predetermined width g, and are nonmagnetic gap plates (not shown) interposed in the respective gaps 24. Are connected in an annular shape by being bonded and fixed across. The nonmagnetic gap plate can be suitably formed from ceramics, for example. In the reactor 10, the length of the core member 16 and the width g of the two gaps 24 are precisely set to realize a desired magnetic path length and inductance.

  The two coils 14 are respectively wound around the legs 18 of the core members 16 facing each other through the gap 24. One end of each coil 14 is electrically connected to each other, and the other end of each coil 14 is connected to an external terminal (not shown) of the reactor 10. The coil 14 is configured by an edgewise coil formed by winding a conductive wire made of a strip-shaped copper wire or the like. Electrical insulation is ensured between adjacent turns of the coil 14 by an insulating material such as enamel coated on itself. In addition, by electrically winding an insulating member such as insulating paper between the turns of the coil 14, the electrical insulation between the turns may be further strengthened. Further, a gap is formed between adjacent turns of the coil 14, and the resin mold molding material applied to the reactor core 12 is filled in the gap, so that the electrical insulation between the turns is achieved. It may be further strengthened.

  In addition, although this embodiment demonstrates the coil 14 as what is comprised by an edgewise coil, it is not limited to this, For example, a coil may be comprised by winding the conducting wire which has a circular cross section.

  The coil 14 is formed by being wound around a bobbin 26 made of an insulating resin. As shown in FIG. 3, the bobbin 26 includes a body portion 28 having a substantially rectangular cylindrical shape, and flange portions 30 and 30 integrally formed at both ends of the body portion 28. The bobbin 26 includes a receiving hole 32 that extends through the body portion 28 and the flange portion 30. The accommodation hole 32 is formed in a rectangular shape substantially corresponding to the outer shape of the leg portion 18 of the core member 16. Further, as described later, the outer peripheral portion of the body portion 28 is formed such that the gap between the inner peripheral portion of the coil 14 and the side surface of the core member 16 is formed larger than the coil end portion side portion in the coil central portion. For example, it is formed in a shape bulging in three directions. Here, the “three sides” in FIG. 3 are the right side and the near side and the back side with respect to the paper surface of FIG.

  In the bobbin 26, one or both of the flange portions 30 may be formed as separate members from the body portion 28, the flange portion may be omitted, or the bobbin itself may be omitted.

  4 is an enlarged view of a portion A in FIG. 2, FIG. 5 is an enlarged view of a portion B in FIG. 2, and FIG. 6 is a cross-sectional view taken along the line CC in FIG. 20). The bobbin 26 is not shown in FIGS.

  As shown in FIG. 6, the leg portion 18 of the core member 16 has a rectangular shape, and thus has four side surfaces connected to the end surface 20. Specifically, the four side surfaces include an inner peripheral side surface 36, an outer peripheral side surface 38, and first and second side surfaces 40 and 42 that are connected to the inner peripheral side surface 36 and the outer peripheral side surface 38, respectively, and are parallel to each other. It is. Hereinafter, the direction orthogonal to the inner peripheral side surface 36 and the outer peripheral side surface 38 is referred to as the width direction, the direction orthogonal to the first and second side surfaces 40 and 42 is referred to as the thickness direction, and the direction orthogonal to the end surface 20 is the length. It is called direction. The first and second side surfaces 40 and 42 will be referred to as the upper side surface 40 and the lower side surface 42 for convenience. However, when the reactor core 12 is installed such that the end surface 20 of the core member 16 is orthogonal to the vertical direction, for example, the first and second side surfaces cannot be said to be the upper side surface and the lower side surface. Please note that.

  As shown in FIG. 4, the coil 14 is formed such that the distance or dimension between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the leg portion 18 of the core member 16 is larger in the vicinity of the gap 24 than both ends of the coil. Yes. Specifically, with respect to the length direction, the coil 14 has a coil end portion 46 located at both ends and a coil central portion 48 located in the vicinity of the gap 24. The distance between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the core member 16 in the coil central portion 48 is larger than the distance between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the core member 16 in the coil end portion 46. The distance is formed large.

  In more detail in accordance with the present embodiment, the coil central portion 48 is located between the gap facing region 50 where the distance from the outer peripheral side surface 38 is constant at the maximum dimension D, and the outer peripheral side surface. The distance change region 52 is formed such that the distance gradually increases or decreases from the minimum dimension d to the maximum dimension D or vice versa. The distance d between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the core member 16 at the coil both end portions 46 substantially corresponds to the thickness dimension of the body portion 28 of the bobbin 26, and between the coil 14 and the core member 16. The dimensions are set to ensure electrical insulation.

  In other words, as compared with the coil end portion 46, in the distance changing region 52, the conductive wire 15 constituting the coil 14 is wound in a direction gradually moving away from the leg portion 18 of the core member 16, and in the gap facing region 50. The conducting wire 15 constituting the coil 14 is wound, for example, several turns at a position shifted by the maximum dimension D in the direction away from the leg portion 18 of the core member 16. Such a coil 14 is easy by prescribing the external dimensions of the body portion 28 of the bobbin 26 (when the bobbin is omitted, the external dimensions of a winding mold for winding and forming the coil 14). Can be formed.

  Here, regarding the coil 14, the maximum dimension D is preferably 20% or more larger than the minimum dimension d. Further, the coil central portion 48 that is formed to have a large distance with respect to the coil 14 is formed to have a length L that is 3 to 6 times the dimension g of the gap 24 with the central position 34 between the gaps 24 as the axis of symmetry. It is preferable. Furthermore, regarding the coil 14, the length of the distance changing region 52 preferably corresponds to 30% or less of the length L of the coil central portion 48. These numerical values related to the coil 14 take into account the balance between effectively reducing eddy current loss as described later and increasing the size of the coil 14 by winding the conductive wire 15 outward. Are preferably selected.

  Moreover, in the leg part 18 of the core member 16, the outer peripheral side part 56 prescribed | regulated by the end surface 20 and the outer peripheral side surface 38 is formed as a curved surface of the curvature radius r for chipping prevention. This curvature radius r is considerably smaller than the curvature radius R of the inner peripheral side portion 54 described later. In an extreme case, the radius of curvature r = 0, that is, the outer peripheral side portion may be formed as a right-angled corner portion that is not subjected to the corner dropping process. In order to prevent such chipping, the corner dropping process by the curved surface having the curvature radius r or no corner dropping process is performed by the upper side portion defined by the end surface 20 and the upper side surface 40 of the leg portion 18 of the core member 16, and The lower side defined by the end surface 20 and the lower side 42 is also applied.

  In the present embodiment, the distance between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the leg portion 18 of the core member 16 is described and illustrated so as to change along the trapezoidal profile. For example, the coil may be formed such that the distance between the inner peripheral portion of the coil and the outer peripheral side surface changes along the arc-shaped profile.

  Referring to FIG. 6, the distance between the coil inner peripheral portion 44 of the coil 14 and the upper side surface 40 of the leg portion 18 of the core member 16, and the coil inner peripheral portion 44 of the coil 14 and the leg portion 18 of the core member 16. The distance between the lower side surface 42 and the lower side surface 42 is set similarly to the distance between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the leg portion 18 of the core member 16 described above.

  On the other hand, referring to FIGS. 5 and 6, the coil 14 is configured such that the distance between the coil inner peripheral portion 44 and the inner peripheral side surface 36 of the leg portion 18 of the core member 16 is constant over the entire length of the coil 14. Is formed. This fixed dimension is the same as the minimum dimension d, and corresponds to the thickness dimension of the body portion 28 of the bobbin 26. The reason why the inner portion of the coil 14 is formed in this way is that the two coils 14 are arranged close to each other in the window portion 22 of the reactor core 12, so that the inner portion of the coil 14 is away from the core member 16 as in the outer portion. This is because if the coil shape is shifted and wound, the adjacent coils 14 and 14 interfere with each other. In order to avoid such interference between the coils 14 and 14, it is conceivable to expand the space between the two leg portions 18 and 18 of the core member 16, but this increases the size of the reactor core 12 and reduces the size of the core member. There arises a disadvantage that a new mold for forming is required.

  While the distance between the coil inner peripheral portion 44 and the inner peripheral side surface 36 of the leg portion 18 of the core member 16 is constant over the entire length of the coil at a minimum distance d, the gap between the end surfaces 20 of the leg portions 18 of the core member 16 is constant. The side portion 54 defined by the end surface 20 and the inner peripheral side surface 36 of the leg portion 18 of the core member 16 is subjected to a corner dropping process so that 24 becomes larger toward the inner peripheral side surface 36 in the width direction.

  Specifically, in this corner dropping process, the inner peripheral side portion 54 of the leg portion 18 is formed as a curved surface having a curvature radius R. This curvature radius R is compared with a curved surface (or a corner dropping plane) having a curvature radius r formed to prevent chipping in the side portion 56 on the outer peripheral side defined by the end surface 20 and the outer peripheral side surface (see FIG. 5). And it is set quite large. Thus, by expanding the gap 24 toward the inner peripheral side surface 36, the magnetic resistance between the leg portions 18 of the core member 16 is increased at this portion. When the corner dropping process is performed with the curved surface having such a curvature radius R, the distance from the start position of the corner dropping process on the end surface 20 to the inner peripheral side surface 36 of the leg portion 18 of the core member 16 corresponds to the curvature radius R. .

  Here, the radius of curvature R is preferably 15 to 40% with respect to the entire width of the leg portion 18 of the core member 16. When the numerical value range is exceeded, the magnetic flux density in the flat portion of the core end face 20 becomes excessively large and magnetic saturation occurs, and the linearity of the inductance of the reactor 12 with respect to the direct current supplied to the coil 14 is ensured. Because it becomes impossible. On the other hand, if it is smaller than the above numerical range, the increase in the magnetic resistance due to the gap expansion at the inner peripheral side portion 54 becomes insufficient, and the effect of reducing the eddy current loss described later is limited.

  As shown in FIG. 7, the corner dropping process performed on the inner peripheral portion 54 of the leg portion 18 of the core member 16 may be performed by the corner dropping side surface 59. In this case, the distance or dimension E from the start position of the corner dropping process on the end surface 20 to the inner peripheral side surface 36 is the same as the case of the radius of curvature R with respect to the full width of the leg portion 18 of the core member 16. It is preferable that it is 15 to 40%. Further, the distance or dimension F in the length direction of the triangular portion 60 cut off by the corner drop plane 59 is preferably the same as the distance E, but may be set to a different value.

  In the present embodiment, the inner peripheral side portion 54 of the leg portion 18 of the core member 16 has been described as being formed as a curved surface defined by the radius of curvature R or a corner dropping plane 59, but the present invention is not limited thereto. Instead, the inner peripheral side portion may be formed by a curved surface or flat surface having any shape as long as the gap 24 expands toward the inner peripheral side surface 36.

  Then, an effect | action and effect of the reactor 10 which consists of the said structure are demonstrated.

  When the coil 14 of the reactor 10 is energized, the reactor core 12 is excited by energization, and the gap 24 between the inside of the core member 16 and each leg 18 becomes a magnetic path. At this time, as shown in FIG. 4, a leakage magnetic flux M is generated in the vicinity of the gap 24 of the leg portion 18 of the core member 16. The leakage magnetic flux M leaks so as to swell outward from the vicinity of the outer peripheral portion 56 and flows from the leg portion 18 of one core member 16 to the leg portion 18 of the other core member 16.

  When such a leakage magnetic flux M intersects with the coil 14 wound around the eddy current, an eddy current is generated in the coil 14, thereby generating an eddy current loss. However, in the reactor 10 of the present embodiment, the coil 14 is formed such that the distance between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the core member 16 is larger than the coil end portions 46 side. Further, this distance is formed so as to be the maximum dimension D in the gap facing region 50 of the coil 14 corresponding to the region where the leakage magnetic flux M swells most. Thereby, the interlinkage area of the leakage magnetic flux M with the coil 14 can be reduced, and eddy current loss can be reduced. As shown in FIG. 6, this effect is not only the distance between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the leg portion 18 of the core member 16, but also the coil inner peripheral portion 44 and the leg portion of the core member 16. 18, and the distance between the coil inner peripheral portion 44 and the lower side surface 42 of the core member 16 is also more conspicuous by forming the coil 14 to be larger. Become.

  Further, if the distance between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the core member 16 is increased to the maximum dimension D over the entire length of the coil, it passes between the coil both end portions 46 and the outer peripheral side surface 38 of the core member 16. Since the magnetic flux increases, the magnetic flux easily interlinks with the coil 14 and the eddy current loss increases. However, such a problem does not occur in the reactor of this embodiment.

  Furthermore, when the distance between the coil inner peripheral portion 44 and the leg portion 18 of the core member 16 is uniformly increased over the entire length of the coil, the resistance loss increases as the conducting wire 15 constituting the coil 14 becomes longer. In the present embodiment, since the coil 14 is formed so that the distance is larger than the coil end portions 46 in the vicinity of the gap 24 between the core members 16, an increase in resistance loss due to an increase in the coil conductor length is minimized. can do.

  On the other hand, as shown in FIG. 6, with respect to the inner peripheral portion of the coil 14 located in the window portion 22 of the reactor core 12, in order to avoid interference between the two adjacent coils 14, the coil inner peripheral portion 44 and The distance from the inner peripheral side surface 36 of the leg portion 18 of the core member 16 is formed to be constant with the minimum dimension d over the entire length of the coil. However, the end surface 20 and the inner peripheral side surface 36 of the leg portion 18 of the core member 16 increase so that the gap 24 between the end surfaces 20 of the leg portions 18 of the core member 16 becomes larger as the gap 24 approaches the inner peripheral side surface 36 in the width direction. The prescribed side portion 54 is subjected to corner processing, whereby the gap 24 expands toward the inner peripheral side surface 36, so that the magnetic resistance between the leg portions 18 of the core member 16 is increased at this enlarged portion. . As a result, it is possible to reduce the amount of leakage magnetic flux M flowing out from the vicinity of the side portion 54 that has been subjected to the corner processing, and it is possible to suppress the leakage magnetic flux M from bulging out toward the window portion 22. As a result, the interlinkage area of the leakage magnetic flux M with the coil 14 can also be reduced in the inner peripheral portion of the coil, and eddy current loss can be reduced.

  As described above, according to the reactor 10 of the present embodiment, with respect to the core member 16, the end face side portion 54 of the leg portion 18 facing the inner peripheral side of the annular reactor core 12 is formed on the leg surface facing the outer peripheral side of the reactor core 12. The amount of leakage flux linkage passing through the coil 14 on the inner peripheral side of the reactor core 12 can be reduced with a simple configuration in which the angle drop processing is greatly performed as compared with the end face side portion 56 of the portion 18. Loss can be effectively reduced.

  In addition, in the reactor 10 of the present embodiment, the coil 14 may be formed so that the distance between the coil inner peripheral portion 44 and the outer peripheral side surface 38 of the core member 16 is increased in the vicinity of the gap 24 between the core members 16. The eddy current loss generated in the coil 14 can be effectively suppressed.

In FIG. 8, the analysis result which verified the effect which reduces the eddy current loss of the coil 14 in the reactor 10 of this embodiment is shown. In the lower diagram in FIG. 8, the right side shows eddy current loss (kw / in) in the cross section of half (9) conductors constituting the coil 14 when the inner peripheral portion 54 of the core member 16 is subjected to the corner dropping process. m ³ ) is shown, and the left side is the coil of the conventional example when the core member 16 without the corner dropping process is used (the distance between the inner periphery of the coil and the entire side surface of the leg of the core member is the minimum dimension) The state of occurrence of eddy current loss in the cross section of half (9) conductors constituting the coil 14b constant in d) is shown. As is apparent from FIG. 8, it can be seen that the eddy current loss indicated by the dot density is considerably reduced in the coil 14 in this embodiment. As a numerical value, the eddy current loss is about 20 compared with the coil 14b of the conventional example. It was confirmed that it can be reduced by about%.

  Next, the reactor 11 of another embodiment is demonstrated with reference to FIG. Since the reactor 11 of this embodiment has substantially the same configuration as the reactor 10 described above, only the different points will be mainly described here, and the same or similar reference numerals are given to the same or similar configurations. Thus, redundant explanations will be omitted.

  In the reactor 11 of this other embodiment, the outer peripheral portion of the coil 14 a is also similar to the inner peripheral portion located in the window portion 22 of the reactor core 12 and the outer peripheral side surface 38 of the core member 16. The coil 14a is formed so that the distance between the two is constant with the minimum dimension d over the entire length of the coil. Further, the outer peripheral side portion 56 of the leg portion 18 of the core member 16 has a curved surface having a radius of curvature smaller than the radius of curvature R of the inner peripheral side portion 54 but larger than the curvature radius r for preventing chipping. (Or equivalent corner-cutting plane). In this way, the radius of curvature for the outer peripheral side portion 56 is regulated by suppressing the occurrence of magnetic saturation due to the decrease in the flat portion of the end surface 20 of the leg portion 18 on the outer peripheral side, and the outer peripheral portion of the coil 14a. This is to effectively reduce eddy current loss. About the structure of those other than these, it is the same as that of the said reactor 10. FIG.

  According to the reactor 11 of the present embodiment, eddy current loss can be effectively reduced not only in the inner peripheral portion of the coil 14a but also in the outer peripheral portion. In addition, since the outer peripheral portion of the coil 14a is formed without bulging outward, the reactor 11 including the coil 14a can be reduced in size in the width direction, and the increase in the length of the coil conductor can be suppressed to minimize resistance loss. It can be suppressed.

  In each of the above embodiments, the distance between the coil inner peripheral portion 44 and the upper side surface 40 of the leg portion 18 of the core member 16, and the coil inner peripheral portion 44, the coil inner peripheral portion 44, and the core member 16. The coils 14 and 14a are formed so that both the distance between the lower surface 42 of the leg portion 18 and the distance between the lower surface 42 of the leg portion 18 are large, but the reactor according to the present invention is not limited to this, and either The coils 14 and 14a may be formed so that only one distance expands in the vicinity of the gap.

  10 reactors, 12 reactor cores, 14 and 14a coils, 15 conductors, 16 core members, 18 legs, 20 end faces, 22 windows, 24 gaps, 26 bobbins, 28 trunks, 30 flanges, 32 receiving holes, 34 centers Position, 36 Inner peripheral side, 38 Outer peripheral side, 40 Upper side, 42 Lower side, 44 Coil inner peripheral part, 46 Coil end part, 48 Coil central part, 50 Gap facing area, 52 Distance changing area, 54 Inner peripheral side Side, 56 Outer peripheral side, 58 Corner dropping plane, D maximum dimension, d minimum dimension, M leakage flux, R, r curvature radius.

Claims (9)

An annular reactor core that includes two U-shaped or U-shaped core members having two leg portions, and that is connected with the end surfaces of the leg portions of the core member facing each other via a gap; A reactor comprising two coils wound respectively around the legs of the core members opposed via the gap,
The end face side portion of the leg portion facing the inner peripheral side of the annular reactor core is subjected to a large angle drop process compared to the end face side portion of the leg portion facing the outer peripheral side of the reactor core. Reactor. The reactor according to claim 1,
In the corner dropping process, the gap between the end faces of the leg portions of the core member is increased as the gap approaches the inner circumference side in the width direction of the leg portions. A reactor that is implemented by forming an end face side portion. The reactor according to claim 2,
In the corner dropping process, the side edge portion on the inner peripheral side of the leg portion of the core member is formed as a curved surface, or the side portion is formed as a corner dropping plane. In the reactor as described in any one of Claims 1-3,
The distance from the start position of the corner-dropping process on the end surface when the corner-dropping process is performed on the end face side part of the leg part facing the inner peripheral side to the inner peripheral side surface of the leg part of the core member is The reactor is 15 to 40% of the entire width of the leg portion of the core member. The reactor according to claim 1,
The core member has a rectangular cross-sectional shape and a leg end face shape, and a distance between an inner peripheral side surface of the leg portion facing an inner peripheral side of the annular reactor core and an inner peripheral portion of the coil is The gap is formed with respect to the distance between the outer peripheral side surface of the leg portion facing the outer peripheral side of the annular reactor core and the inner peripheral portion of the coil while the coil is formed to have a constant dimension over the entire length of the coil. The reactor in which the dimension in the vicinity is formed larger than the said fixed dimension in the both ends of the said coil. The reactor according to claim 5,
The dimension in the vicinity of the gap is at least one of the distances between the first and second side surfaces of the leg portion of the core member excluding the inner peripheral side surface and the outer peripheral side surface and the inner peripheral portion of the coil. A reactor characterized in that it is formed larger than the fixed dimension at both ends of the coil. In the reactor according to claim 5 or 6,
The coil portion having a large distance is formed in a length of 3 to 6 times the dimension of the gap, with the center position between the gaps as the axis of symmetry. In the reactor as described in any one of Claims 5-7,
The reactor has a maximum dimension at a position corresponding to the gap, and the maximum dimension is 20% or more larger than a minimum dimension which is the distance at both ends of the coil. In the reactor as described in any one of Claims 5-8,
The coil portion having a large distance is formed to have a length of 3 to 6 times the dimension of the gap with the center position between the gaps as the axis of symmetry, and the distance change corresponding to 30% or less of the length. The reactor, wherein the distance gradually increases or decreases between a minimum dimension and a maximum dimension in an area, and the distance is set to the maximum dimension outside the distance change area.

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