Magnetic core and coil device

Abstract

To implement improvement of inductance or miniaturization of a coil.SOLUTION: A magnetic core has a plurality of leg portions and a pair of connecting portions that magnetically connect one end portions to each other and magnetically connect the other end portions to each other in a length direction of the plurality of leg portions, respectively. A vertical gap which is a magnetic gap perpendicular to the length direction is formed in at least one of the plurality of leg portions and the pair of connecting portions, and the plurality of leg portions includes a pair of outer leg portions that magnetically connect one end portions to each other and magnetically connect the other end portions of the pair of connecting portions to each other in the length direction, respectively. A frame-shaped portion is formed by the pair of outer leg portions and the pair of connecting portions, and an inclined gap which is a magnetic gap connecting an inside corner and an outside corner is formed on at least one corner portion of the frame-shaped portion.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a magnetic core and a coil device. [Background technology]

[0002] Among coil devices such as reactors equipped with a magnetic core, those equipped with a gapped magnetic core are known. Patent Document 1 describes a reactor equipped with a gapped magnetic core. By using a gapped magnetic core, magnetic saturation can be suppressed.

[0003] In the gapped magnetic core described in Patent Document 1, two rectangular gap plates are sandwiched between the legs of a pair of U-shaped magnetic cores, thereby forming two magnetic gaps perpendicular to the magnetic path. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-68348 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when a conventional gapped core in which only a magnetic gap perpendicular to the magnetic path is formed as described in Patent Document 1 is used, portions of low magnetic flux density occur at the corners of the magnetic core. In other words, the performance of the magnetic material is not fully utilized in the conventional gapped core, and there is room for improvement in inductance or miniaturization.

[0006] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to realize an improvement in inductance or a reduction in size of a magnetic core. [Means for solving the problem]

[0007] A magnetic core in one embodiment of the present invention has a plurality of legs and a pair of connecting parts that magnetically connect one end and the other end of the plurality of legs in the longitudinal direction, respectively, and a vertical gap, which is a magnetic gap perpendicular to the longitudinal direction, is formed in at least one of the plurality of legs and the pair of connecting parts, the plurality of legs include a pair of outer legs that magnetically connect one end and the other end of the pair of connecting parts in the longitudinal direction, respectively, the pair of outer legs and the pair of connecting parts form a frame-shaped part, and an inclined gap, which is a magnetic gap connecting an inside corner and an outside corner, is formed in at least one corner of the frame-shaped part.

[0008] In the above magnetic core, one end face of one connecting portion may be a first inclined end face inclined with respect to the longitudinal direction of the connecting portion, one end face of one outer leg may be a second inclined end face inclined with respect to the longitudinal direction of the outer leg, and an inclined gap may be formed in the gap between the first inclined end face and the second inclined end face.

[0009] In the magnetic core described above, two inclined gaps may be formed in the frame portion, and inclined gaps may be formed adjacent to both ends of one of the connecting portions.

[0010] In the magnetic core described above, two inclined gaps may be formed in the frame-shaped portion, and the inclined gaps may be formed adjacent to one end of one coupling portion and adjacent to the other end of the other coupling portion.

[0011] In the magnetic core described above, inclined gaps may be formed at the four corners of the frame-shaped portion.

[0012] In the magnetic core described above, a vertical gap may be formed between one end of at least one of the legs and one of the connecting portions.

[0013] In the magnetic core described above, a vertical gap may be formed between the other end of at least one of the legs and the other connecting portion.

[0014] In the magnetic core, a vertical gap may be formed in the middle of at least one of the legs in the longitudinal direction.

[0015] A closed magnetic circuit may be formed by a pair of outer legs and a pair of connecting portions, and a ratio X / G of a sum of lengths X of inclined gaps to a sum of lengths G of vertical gaps formed in the closed magnetic circuit may be 0.33 or more.

[0016] In the above magnetic core, a closed magnetic circuit may be formed by a pair of outer legs and a pair of connecting parts, and a ratio X / G of the sum of lengths X of the inclined gaps to the sum of lengths G of the vertical gaps formed in the closed magnetic circuit may be 3 or less.

[0017] In the magnetic core described above, the plurality of legs may include a center leg disposed between a pair of outer legs.

[0018] In the above magnetic core, a closed magnetic circuit may be formed by the center leg, one outer leg, and a pair of connecting parts, and a ratio X / G of the sum of lengths X of the inclined gaps to the sum of lengths G of the vertical gaps formed in the closed magnetic circuit may be 0.33 or more.

[0019] In the above magnetic core, a closed magnetic circuit may be formed by the center leg, one outer leg, and a pair of connecting parts, and a ratio X / G of the sum of lengths X of the inclined gaps to the sum of lengths G of the vertical gaps formed in the closed magnetic circuit may be 3 or less.

[0020] In the above magnetic core, a first closed magnetic circuit is formed by the center leg, one outer leg, and a pair of connecting parts, and a second closed magnetic circuit is formed by the center leg, the other outer leg, and a pair of connecting parts, and the sum of the lengths X of the inclined gaps formed in the first closed magnetic circuit and the sum of the lengths X of the inclined gaps formed in the second closed magnetic circuit may be equal.

[0021] According to one embodiment of the present invention, there is provided a coil device including the above-mentioned magnetic core and a winding attached to any one of the multiple legs. Effect of the Invention

[0022] According to one embodiment of the present invention, it is possible to improve the inductance of the coil device or reduce the size of the coil device. [Brief description of the drawings]

[0023] [Figure 1] 1 is an external view of a reactor according to a first embodiment of the present invention; [Diagram 2] FIG. 2 is a front view of the iron core according to the first embodiment of the present invention. [Diagram 3] FIG. 3 is a diagram showing dimensions of an iron core according to the first embodiment of the present invention. [Figure 4] FIG. 13 is a diagram showing the simulation results of magnetic flux density distribution in a conventional EI-type core. [Diagram 5] FIG. 4 is a diagram showing a simulation result of magnetic flux density distribution in the iron core according to the first embodiment of the present invention. [Figure 6] 4 is a graph showing the DC superposition characteristics of the coil device according to the first embodiment of the present invention. [Figure 7] FIG. 6 is a front view of an iron core according to a second embodiment of the present invention. [Figure 8] FIG. 11 is a front view of an iron core according to a third embodiment of the present invention. [Figure 9] FIG. 11 is a front view of an iron core according to a fourth embodiment of the present invention. [Figure 10] FIG. 11 is a front view of an iron core according to a fifth embodiment of the present invention. [Figure 11] FIG. 13 is a front view of an iron core according to a sixth embodiment of the present invention. [Figure 12] FIG. 13 is a front view of an iron core according to a seventh embodiment of the present invention. [Figure 13] FIG. 13 is a diagram showing a closed magnetic circuit formed in an iron core according to a seventh embodiment of the present invention. [Figure 14] FIG. 13 is a front view of an iron core according to an eighth embodiment of the present invention. [Figure 15] FIG. 13 is a front view of an iron core according to a ninth embodiment of the present invention. [Figure 16] FIG. 23 is a front view of an iron core according to a tenth embodiment of the present invention. [Figure 17] FIG. 23 is a front view of an iron core according to an eleventh embodiment of the present invention. [Figure 18] FIG. 23 is a front view of an iron core according to a twelfth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same or corresponding items are given the same or corresponding reference numerals, and duplicated descriptions are omitted. In addition, when multiple items with the same reference numerals are displayed in each drawing, the reference numerals are not necessarily given to all of the multiple displays, and the reference numerals are appropriately omitted for some of the multiple displays.

[0025] First Embodiment 1 is an external view of a reactor 1 (coil device) according to a first embodiment of the present invention. The reactor 1 includes a coil 2 (winding) and an iron core 3 (magnetic core). Each member constituting the coil 2 and the iron core 3 (an I-core 3Ia, a T-core 3Ta, and a pair of I-cores 3Ib, which will be described later) is held (i.e., their relative positions are fixed) by a holding member (not shown) such as an insulating bobbin.

[0026] In the following description, the direction from the upper left to the lower right in FIG. 1 is defined as the X direction, the direction from the lower left to the upper right as the Y direction, and the direction from the bottom to the top as the Z direction. The X direction, Y direction, and Z direction are perpendicular to each other. The reactor 1 may be used with any of the X direction, Y direction, Z direction, and intermediate directions oriented vertically. In the following description, for convenience of explanation, the X direction may be referred to as the width direction or left-right direction, the Y direction as the depth direction or front-rear direction, and the Z direction as the height direction or up-down direction.

[0027] The coil 2 is a spirally wound conductor with an insulating coating, such as an enameled wire. The conductor is made of, for example, copper or aluminum. The coil 2 is an edgewise wound rectangular wire, but may be wound in a different manner, or may be made of round wire or twisted wire. The coil 2 may also be made of a conductor in the form of a foil or strip, such as a copper foil coil or copper strip coil.

[0028] 2 is a front view of the core 3 according to the first embodiment of the present invention. The core 3 is an approximately figure-8 (or L-shaped) member assembled from an I-core 3Ia, a T-core 3Ta, and a pair of I-cores 3Ib. The I-core 3Ia, the T-core 3Ta, and the I-core 3Ib are laminated cores formed by laminating electromagnetic steel sheets, such as silicon steel sheets, in the Y direction and integrating them by, for example, bonding, brazing, or welding.

[0029] The core 3 has a center leg 31 to which the coil 2 is attached (i.e., inserted into the hollow portion of the coil 2), a pair of outer legs 32 (outer legs 32A, 32B) arranged in parallel on both sides of the center leg 31, and a pair of connecting parts 33 connecting the center leg 31 and the pair of outer legs 32. The connecting parts 33 include a connecting part 33A (first yoke) that is magnetically connected to one end (upper end in FIG. 2) of the center leg 31 and the pair of outer legs 32A, 32B, and a connecting part 33B (second yoke) that is magnetically connected to the other end (lower end in FIG. 2) of the center leg 31 and the pair of outer legs 32A, 32B. The connecting part 33A magnetically connects one end of the multiple legs (center leg 31, outer legs 32A, 32B) in the length direction, and the connecting part 33B magnetically connects the other end of the multiple legs. A frame-shaped portion is formed by the pair of outer legs 32A, 32B and the pair of connecting portions 33A, 33B. Note that the "middle leg" and the "outer leg" are collectively referred to as "legs".

[0030] In this embodiment, the center leg 31 and the connecting portion 33B are formed from a T-shaped core 3Ta, the pair of outer leg portions 32A, 32B are formed from a pair of I-shaped cores 3Ib, 3Ib respectively, and the connecting portion 33A is formed from an I-shaped core 3Ia.

[0031] One end face in the length direction (Z direction) of the outer legs 32A, 32B is an inclined end face 32As, 32Bs inclined at 45° with respect to the Z direction. In addition, both end faces in the length direction (X direction) of the connecting portion 33B are also inclined end faces 33Bs, 33Bs inclined at 45° with respect to the X direction (i.e., 45° with respect to the Z direction). An inclined gap 30s, which is a magnetic gap, is formed between the inclined end faces 32As, 32Bs of the outer legs 32A, 32B and each inclined end face 33Bs, 33Bs of the connecting portion 33B. In this embodiment, the two inclined gaps 30s have the same gap length (the length of the inclined gap 30s in a direction perpendicular to the inclined end faces 32As, 32Bs).

[0032] A corner C of the frame-shaped portion is formed from one end of the wedge shape of the outer leg portion 32A on which the inclined end surface 32As is formed and one end of the wedge shape of the connecting portion 33B on which the inclined end surface 33Bs is formed. A The inclined gap 30s is formed at the corner C A Inside corner C i (i.e., corner C A inside corner) and outside corner C o (i.e., corner C A The outer corners of the panel are connected to each other.

[0033] In addition, a corner C of the frame-shaped portion is defined by one end of the wedge shape of the outer leg portion 32B on which the inclined end surface 32Bs is formed and the other end of the wedge shape of the connecting portion 33B on which the inclined end surface 33Bs is formed. B The inclined gap 30s is formed at the corner C B Inside corner C i and corner C o It is formed to communicate with.

[0034] The end face of the center leg 31 is a vertical end face 31p perpendicular to the length direction (Z direction) of the center leg 31. A vertical gap 30pa (30p), which is a magnetic gap, is formed between the vertical end face 31p of the center leg 31 and the side face of the connecting portion 33A. The inclined gap 30s and the vertical gap 30pa are formed perpendicular to the ZX plane.

[0035] In this embodiment, the inclined gap 30s and the vertical gap 30pa are air gaps, but a gap plate made of non-magnetic resin or ceramics may be inserted between the inclined end faces or the vertical end faces to form a magnetic gap. Also, the magnetic gap may be formed by filling the inclined end faces or the vertical end faces with an adhesive or a thermosetting resin and curing it.

[0036] A computer simulation was performed on the characteristics of the reactor 1 according to the first embodiment of the present invention. Figure 3 is a diagram showing the dimensions of a model of the iron core 3 used in the computer simulation. The depth d (Y direction) of the iron core 3 is 65 mm. The number of turns of the coil 2 was 105.

[0037] [Table 1]

[0038] Table 1 shows the dimensions (G, X, X / G) of the vertical gap 30pa and the inclined gap 30s in each model of the iron core 3 used in the computer simulation, and the index (ΔL 13A , L 2A / L 13A ) is shown. In Table 1, "G" is the gap length G [mm] of the vertical gap 30pa, and "X" is the gap length X [mm] of the inclined gap 30s. "X / G" is the ratio of the gap length X of the inclined gap 30s to the gap length G of the vertical gap 30pa.

[0039] The computer simulation was performed for 11 conditions (models M1 to M11) in which the gap length G of the vertical gap 30pa and the gap length X of the inclined gap 30s were different. Model M1 was a comparative example (conventional technology), and models M2 to M11 were examples of this embodiment. In order to make the gap length in the magnetic circuit uniform, the sum of the gap length G and the gap length X was set to a constant value (1.6 mm). Model M1 (X = 0 mm) is a model (comparative example) that does not have the inclined gap 30s and corresponds to a conventional EI-type magnetic core. Model M11 (G = 0 mm) is a model that does not have the vertical gap 30pa (i.e., the vertical end surface 31p of the center leg portion 31 is in close contact with or joined to the side surface of the connecting portion 33A).

[0040] 4 and 5 are diagrams showing the magnetic flux density distribution of the reactor 1 obtained by computer simulation. FIG. 4 is a magnetic flux density distribution diagram of the model M1 (comparative example), and FIG. 5 is a magnetic flux density distribution diagram of the model M5 (embodiment). In FIG. 4 and FIG. 5, except for the outline, the higher the brightness (brighter), the higher the magnetic flux density. In the conventional EI-type iron core (model M1) shown in FIG. 4, there are parts with low magnetic flux density at both ends and the center in the length direction of the connecting parts 33A and 33B. In contrast, in the embodiment of the present invention (model M5) shown in FIG. 5, the decrease in magnetic flux density is alleviated overall, and the decrease in magnetic flux density is almost eliminated especially in the vicinity of the inclined gap 30s. That is, it can be seen from FIG. 4 and FIG. 5 that the magnetic flux density of the iron core 3 is uniformed by introducing the inclined gap 30s into the iron core 3.

[0041] Figure 6 is a graph showing the DC superposition characteristics of Reactor 1 obtained by computer simulation. In the graph of Figure 6, the horizontal axis represents effective current [A], and the vertical axis represents inductance [mH].

[0042] In Table 1, "ΔL 13A " and "L 2A / L 13A" is an index showing the characteristics of the reactor 1, calculated from the simulation results of the DC superposition characteristics shown in the graph of FIG. 6. 13A " is an index showing the rate of increase in inductance from the conventional EI type core (model M1), and "L 13A / L 2A " is an index showing the stability of inductance against fluctuations in effective current.

[0043] Specifically, "ΔL 13A " is the rate of increase in inductance based on the inductance of Reactor 1 using a conventional EI-type core (Model M1) when an effective current of 13 A is passed through it, and is calculated using the following formula (1). TIFF2025011344000003.tif9170 Here, "L Mn "(13A)" is the inductance of reactor 1 using iron core 3 of model Mn (where "n" is an integer from 1 to 11) when an effective current of 13A flows.

[0044] Also, "L 13A / L 2A " is the inductance L when an effective current of 2A flows 2A Inductance L when an effective current of 13A flows, based on 13A The relative size of "L 13A / L 2A The larger " (i.e., closer to 1), the less the inductance fluctuates (decreases) in the normal range of effective current (for example, 2 A to 13 A), and the more stable the inductance characteristics.

[0045] As shown in Table 1, for models M3 to M11 in which the gap length X of the inclined gap 30s is 0.4 mm or more (or X / G is 0.33 or more), an improvement in inductance was observed compared to the conventional EI type core (model M1).

[0046] In addition, reactors are easier to use if their inductance L is stable against current fluctuations, and it is desirable that the fluctuation range (reduction range) of inductance L in the normal range of effective current (for example, 2A to 13A) be within approximately 10%. From Table 1, for models M1 to M8 in which the gap length X of the inclined gap 30s is 1.2mm or less (or X / G is 3 or less), the index of the fluctuation rate of inductance L in the normal range of effective current (2A to 13A) is "L 13A / L 2A " was 0.9 or more (i.e., the fluctuation range was less than 10%), and stable inductance characteristics were observed in the normal range of effective current.

[0047] The number and positions of the inclined gaps 30s and the vertical gaps 30pa are not limited to those of the first embodiment. Below, other embodiments in which the numbers and positions of the inclined gaps 30s and the vertical gaps 30p are different are exemplified. The second to ninth embodiments of the present invention described below differ from the first embodiment only in the configurations of the iron cores 3A to 3H (particularly, the numbers and positions of the inclined gaps 30s and the vertical gaps 30p).

[0048] <Second embodiment> 7 is a front view of an iron core 3A according to a second embodiment of the present invention. The iron core 3A is a laminated iron core assembled from one U-shaped iron core 3Ua and one T-shaped iron core 3Ta and having a substantially figure eight (or square) shape.

[0049] In this embodiment, the center leg 31 and the connecting portion 33B are formed of a T-shaped core 3Tb, and the outer legs 32A, 32B and the connecting portion 33A are formed of a U-shaped core 3Ua. In addition, both end faces of the U-shaped core 3Ua are inclined end faces 32As, 32Bs.

[0050] In the core 3 of the first embodiment described above, a U-shaped (or C-shaped) core is formed by joining three I-shaped cores 3Ia, 3Ib, and 3Ib, but in this embodiment, by using a U-shaped core 3Ua, the number of parts is reduced and the process of joining the three I-shaped cores 3Ia, 3Ib, and 3Ib is also eliminated, making it possible to reduce the manufacturing costs of the core.

[0051] <Third embodiment> 8 is a front view of an iron core 3B according to a third embodiment of the present invention. The iron core 3B is a laminated iron core having a substantially figure eight (or square) shape, assembled from an E-core 3Ea and a T-core 3Tb.

[0052] In this embodiment, a portion 31A of the center leg 31, a pair of outer legs 32A, 32B and the connecting portion 33A are formed from an E-shaped core 3Ea, and the remaining portion 31B of the center leg 31 and the connecting portion 33B are formed from a T-shaped core 3Tb.

[0053] One end face in the length direction (Z direction) of the outer legs 32A, 32B is an inclined end face 32As, 32Bs inclined at 45° with respect to the Z direction. In addition, both end faces in the length direction (X direction) of the connecting portion 33B are also inclined end faces 33Bs, 33Bs inclined at 45° with respect to the X direction. An inclined gap 30s is formed between the inclined end faces 32As, 32Bs of the outer legs 32A, 32B and each inclined end face 33Bs, 33Bs of the connecting portion 33B. The two inclined gaps 30s have the same gap length.

[0054] One end face in the longitudinal direction (Z direction) of each of the portions 31A, 31B of the center leg 31 is a vertical end face 31Ap, 31Bp perpendicular to the Z direction. A vertical gap 30pb (30p) is formed between the vertical end faces 31Ap, 31Bp of each of the portions 31A, 31B of the center leg 31.

[0055] As in this embodiment, a vertical gap 30pb may be provided in the longitudinal intermediate portion of center leg 31. Also, in this embodiment, portions 31A and 31B of center leg 31 have the same length, but they may have different lengths.

[0056] <Fourth embodiment> 9 is a front view of an iron core 3C according to a fourth embodiment of the present invention. The iron core 3C is a laminated iron core having a substantially figure eight (or a square) shape, assembled from an E-core 3Eb and an I-core 3Ic.

[0057] In this embodiment, the center leg 31, the pair of outer legs 32A, 32B and the connecting portion 33A are formed of an E-shaped core 3Eb, and the connecting portion 33B is formed of an I-shaped core 3Ic.

[0058] One end face in the length direction (Z direction) of the outer legs 32A, 32B is an inclined end face 32As, 32Bs inclined at 45° with respect to the Z direction. In addition, both end faces in the length direction (X direction) of the connecting portion 33B are also inclined end faces 33Bs, 33Bs inclined at 45° with respect to the X direction. An inclined gap 30s is formed between the inclined end faces 32As, 32Bs of the outer legs 32A, 32B and each inclined end face 33Bs, 33Bs of the connecting portion 33B. The two inclined gaps 30s have the same gap length.

[0059] An end face of center leg 31 in the longitudinal direction (Z direction) is vertical end face 31p perpendicular to the Z direction. A vertical gap 30pa is formed between vertical end face 31p of center leg 31 and a side face of connecting portion 33B.

[0060] In the first and second embodiments, the vertical gap 30pa is provided between the connecting portion 33A and the middle leg portion 31, but in this embodiment, it is provided between the connecting portion 33B and the middle leg portion 31. As in this embodiment, the vertical gap 30pa and the inclined gap 30s may be provided at a position adjacent to the same connecting portion 33B (or connecting portion 33A).

[0061] <Fifth embodiment> 10 is a front view of an iron core 3D according to a fifth embodiment of the present invention. The iron core 3D is a laminated iron core assembled from a pair of F-shaped iron cores 3Fa and having a substantially figure eight (or square) shape.

[0062] In this embodiment, a portion 31A of the center leg 31, the outer leg 32A and the connecting portion 33A are formed by one F-shaped iron core 3Fa, and the remaining portion 31B of the center leg 31, the outer leg 32B and the connecting portion 33B are formed by the other F-shaped iron core 3Fa.

[0063] One end face of the outer legs 32A, 32B in the length direction (Z direction) is an inclined end face 32As, 32Bs inclined at 45° with respect to the Z direction. One end face of the connecting parts 33A, 33B in the length direction (X direction) is also an inclined end face 33As, 33Bs inclined at 45° with respect to the X direction. An inclined gap 30s is formed between the inclined end faces 32As, 32Bs of the outer legs 32A, 32B and the inclined end faces 33Bs, 33As of the connecting parts 33B, 33A, respectively. The two inclined gaps 30s have the same gap length.

[0064] One end face in the longitudinal direction (Z direction) of parts 31A and 31B of center leg 31 is vertical end face 31Ap, 31Bp perpendicular to direction Z. A vertical gap 30pb is formed between vertical end faces 31Ap, 31Bp of center leg 31.

[0065] In the first to fourth embodiments, a pair of inclined gaps 30s, 30s are formed adjacent to both ends of one connecting portion 33B, but in this embodiment, one inclined gap 30s is formed adjacent to one connecting portion 33A, and another inclined gap 30s is formed adjacent to the other connecting portion 33B. As in this embodiment, the pair of inclined gaps 30s, 30s may be provided at diagonal portions of the iron core (in other words, at positions adjacent to different outer legs 32 and different connecting portions 33, respectively).

[0066] Sixth Embodiment 11 is a front view of an iron core 3E according to a sixth embodiment of the present invention. The iron core 3E is a laminated iron core having a substantially figure eight (or letter S) shape assembled from a pair of T-cores 3Tb and a pair of I-cores 3Id.

[0067] In this embodiment, a portion 31A of the center leg 31 and the connecting portion 33A are formed by one T-shaped iron core 3Tb, the remaining portion 31B of the center leg 31 and the connecting portion 33B are formed by the other T-shaped iron core 3Tb, and the outer legs 32A and 32B are formed by I-shaped iron cores 3Id and 3Id, respectively.

[0068] Both end faces of the outer legs 32A and 32B in the length direction (Z direction) are inclined end faces 32As, 32As and 32Bs, 32Bs inclined at 45° with respect to the Z direction. In addition, both end faces of the connecting parts 33A and 33B in the length direction (X direction) are inclined end faces 33As, 33As and 33Bs, 33Bs inclined at 45° with respect to the X direction. An inclined gap 30s is formed between one inclined end face 32As and one inclined end face 33As, between the other inclined end face 32As and one inclined end face 33Bs, between one inclined end face 32Bs and the other inclined end face 33As, and between the other inclined end face 32Bs and the other inclined end face 33Bs. The four inclined gaps 30s have the same gap length.

[0069] One end surface of the parts 31A and 31B of the center leg 31 in the longitudinal direction (Z direction) is a vertical end surface 31Ap, 31Bp perpendicular to the Z direction. A vertical gap 30pb is formed between the vertical end surfaces 31Ap, 31Bp of the center leg 31.

[0070] In the first to fifth embodiments, two inclined gaps 30s are provided in the core 3, 3A to 3D, but four inclined gaps 30s may be provided at the four corners of the core as in the present embodiment. Note that although an odd number of inclined gaps 30s (for example, one or three) can be provided in the core, providing the same number of inclined gaps 30s in each closed magnetic circuit in the core results in a more uniform distribution of magnetic flux density and a higher inductance can be obtained.

[0071] Seventh embodiment 12 is a front view of an iron core 3F according to a seventh embodiment of the present invention. The iron core 3F is a laminated core having a substantially figure eight (or letter S) shape assembled from a pair of I-cores 3Ic, a pair of I-cores 3Id, and one I-core 3Ie.

[0072] In this embodiment, the center leg 31 is formed of an I-core 3Ie, the outer legs 32A and 32B are formed of I-cores 3Id and 3Id respectively, and the connecting parts 33A and 33B are formed of I-cores 3Ic and 3Ic respectively.

[0073] Both end faces of the outer legs 32A and 32B in the length direction (Z direction) are inclined end faces 32As, 32As and 32Bs, 32Bs inclined at 45° with respect to the Z direction. In addition, both end faces of the connecting parts 33A and 33B in the length direction (X direction) are inclined end faces 33As, 33As and 33Bs, 33Bs inclined at 45° with respect to the X direction. An inclined gap 30s is formed between one inclined end face 32As and one inclined end face 33As, between the other inclined end face 32As and one inclined end face 33Bs, between one inclined end face 32Bs and the other inclined end face 33As, and between the other inclined end face 32Bs and the other inclined end face 33Bs. The four inclined gaps 30s have the same gap length X.

[0074] Both end faces of the center leg 31 in the longitudinal direction (Z direction) are vertical end faces 31p, 31p perpendicular to the Z direction. Vertical gaps 30pa, 30pa are formed between the vertical end faces 31p, 31p of the center leg 31 and the side faces of the connecting portions 33A, 33B, respectively. The two vertical gaps 30pa have the same gap length X.

[0075] In the first to sixth embodiments, one vertical gap 30p (30pa, 30pb) is provided in the core 3, 3A to 3E, but two vertical gaps 30p may be provided in the core as in this embodiment.

[0076] As shown in FIG. 13, two closed magnetic paths (first closed magnetic path P1, second closed magnetic path P2) are formed in the eight-shaped iron core 3F of this embodiment. In order to obtain a higher inductance by uniforming the magnetic flux density in the iron core 3F, it is preferable to make the sum of the gap lengths X and G of the magnetic gaps (inclined gaps 30s, vertical gaps 30p) included in each closed magnetic path P1, P2 uniform. It is also preferable to make the sum of the gap lengths X of the inclined gaps 30s included in each closed magnetic path P1, P2 uniform. It is also preferable to make the sum of the gap lengths G of the vertical gaps 30p included in each closed magnetic path P1, P2 uniform. The same can be said about the eight-shaped iron cores 3, 3A to 3H according to the first to ninth embodiments.

[0077] Eighth embodiment 14 is a front view of an iron core 3G according to an eighth embodiment of the present invention. The iron core 3G is a laminated core that is assembled from a pair of I-shaped iron cores 3Ia, a pair of I-shaped iron cores 3If, and one I-shaped iron core 3Ie and has an approximately figure-8 (or a letter S) shape, with an inclined gap 30s, shown by a dashed line, added to at least one of the four corners. Note that it is preferable to provide the same number (two or four) of inclined gaps 30s in each of the closed magnetic circuits P1 and P2 formed in the iron core 3G.

[0078] For example, when gaps 30s are provided at all four corners of the core 3G, each I-core 3Ia is divided into one I-core 3Ic having inclined end faces 33As (or inclined end faces 33Bs) formed at both ends in the length direction, and two triangular cores 34. The triangular core 34 has two vertical end faces 34p that are perpendicular to each other, and one inclined end face 34s inclined at an angle of, for example, 45° with respect to each vertical end face 34p. An inclined gap 30s is formed between the inclined end face 34s of the triangular core 34 and the inclined end face 33As (or inclined end face 33Bs) of the I-core 3Ic.

[0079] Further, a vertical gap 30pc is formed between the vertical end faces 32Ap (or the inclined end faces 32Bp) formed at both ends in the length direction of each I-shaped core 3If and one vertical end face 34p of the triangular core 34.

[0080] In this case, the center leg 31 is formed by an I-core 3Ie, the outer legs 32A and 32B are formed by I-cores 3If and 3If respectively, and the connecting parts 33A and 33B are formed by one I-core 3Ic and two triangular cores 34 respectively.

[0081] The number of inclined gaps 30s provided in the iron core 3G is not limited to four, and one, two, or three inclined gaps 30s may be provided at the corners of the iron core 3G. It is preferable to provide the same number of inclined gaps 30s (for example, one each or two each) in the two closed magnetic circuits of the iron core 3G.

[0082] In the first to seventh embodiments, the vertical gap 30p (30pa, 30pb) is provided only in the middle leg portion 31 (or between the middle leg portion 31 and the connecting portions 33A, 33B), but as in this embodiment, the vertical gap 30p (vertical gap pc in this embodiment or vertical gap 30pd described later) may also be provided in the outer leg portions 32A, 32B (or between the outer leg portions 32A, 32B and the connecting portions 33A, 33B).

[0083] Also, as in this embodiment, three or more vertical gaps 30p may be provided in the closed magnetic circuit. By increasing the number of vertical gaps 30p (in other words, by decreasing the X / G value), stable inductance characteristics can be obtained in the normal range of effective current. Also, by increasing the number of vertical gaps 30p, the gap length of each vertical gap 30p can be shortened, and leakage flux in the vertical gaps 30p can be reduced.

[0084] <Ninth embodiment> 15 is a front view of an iron core 3H according to a ninth embodiment of the present invention. The iron core 3H is an approximately eight-shaped (or square-shaped) laminated core assembled from a pair of E-shaped iron cores 3Ec, with an inclined gap 30s, shown by the dashed line, provided in at least one of the four corners.

[0085] For example, when gaps 30s are provided at all four corners of the core 3H, each E-core 3Ec is divided into one T-core 3Tb and two I-cores 3Ig. In this case, the connecting portion 33A and a part 31A of the center leg 31 (or the connecting portion 33B and a part 31B of the center leg 31) are formed of the T-core 3Tb, and the parts 32AA, 32AB, 32BA, and 32BB of the outer legs 32A and 32B are each formed of the I-core 3Ig.

[0086] The T-core 3Tb has inclined end faces 33As (or inclined end faces 33Bs) at both ends in the X direction, and a vertical end face 31Ap (or inclined end face 31Bp) at one end in the Z direction. The I-core 3Ig (i.e., parts 32AA, 32AB of the outer leg 32A, or parts 32BA, 32BB of the outer leg 32B) has inclined end faces 32As or 32Bs at one end in the length direction (Z direction), and vertical end faces 32AAp, 32ABp or 32BAp, 32BBp at the other end.

[0087] An inclined gap 30s is formed between the inclined end face 33As or 33Bs of the T-core 3Tb and the inclined end face 32As or 32Bs of the I-core 3Ig. The four inclined gaps 30s have the same gap length. A vertical gap 30pb is formed between the vertical end faces 31Ap, 31Bp of the pair of T-cores 3Tb.

[0088] Furthermore, a vertical gap 30pd is formed between a vertical end face 32AAp (or a vertical end face 32ABp) of the I-shaped core 3Ig constituting a part 32AA of the outer leg 32A (or a part 32BA of the outer leg 32B) and a vertical end face 32ABp of the I-shaped core 3Ig constituting another part 32AB of the outer leg 32A (or another part 32BB of the outer leg 32B). Each vertical gap 30pd has the same gap length. Furthermore, in this embodiment, the vertical gap 30pb and the vertical gap 30pd also have the same gap length.

[0089] Also, a configuration in which one inclined gap 30s is provided in each E-shaped core 3Ec, or a configuration in which two inclined gaps 30s are provided in one E-shaped core 3Ec may be used.

[0090] When each E-core 3Ec has one inclined gap 30s, each E-core 3Ec is divided into one F-core 3Fb and one I-core 3Ig. In this case, the connecting portion 33A, a part 31A of the center leg 31, and a part 32AA of one outer leg 32A (or a part 32BA of the outer leg 32B) are made of the F-core 3Fb, and the part 32BA of the other outer leg 32B (or a part 32AA of the outer leg 32A) is made of the I-core 3Ig. Also, the connecting portion 33B, a part 31B of the center leg 31, and a part 32AB of one outer leg 32A (or a part 32BB of the outer leg 32B) are made of the F-core 3Fb, and the part 32BB of the other outer leg 32B (or a part 32AB of the outer leg 32A) is made of the I-core 3Ig.

[0091] An inclined gap 30s is formed between the inclined end surface 33As (or the inclined end surface 33Bs) of the F core 3Fb and the inclined end surface 32As (or the inclined end surface 32Bs) of the I core 3Ig. A vertical gap 30pd is formed between the vertical end surface 32AAp of one F core 3Fb (or one I core 3Ig) and the vertical end surface 32ABp of the other F core 3Fb (or the other I core 3Ig), and between the vertical end surface 32BAp of one F core 3Fb (or one I core 3Ig) and the vertical end surface 32BBp of the other F core 3Fb (or the other I core 3Ig). Furthermore, a vertical gap 30pb is formed between the vertical end surface 31Ap of one F core 3Fb and the vertical end surface 31Bp of the other F core 3Fb.

[0092] As in this embodiment, vertical gaps 30pd may be provided at the center in the length direction (Z direction) of center leg 31 and outer leg 32. By providing vertical gaps 30pb at the center in the length direction of center leg 31 and outer leg 32, it is possible to reduce leakage magnetic flux in the vertical gaps.

[0093] Tenth embodiment Fig. 16 is a front view of a reactor 1I according to a tenth embodiment of the present invention. The reactor 1I includes a pair of coils 2 (2A, 2B) and an iron core 3I. Note that in Fig. 16, cross sections of the coils 2A and 2B are shown. The iron core 3I is a rectangular (or roughly O-shaped) laminated core assembled from a pair of U-shaped iron cores 3Ub, with inclined gaps 30s added to two diagonal corners.

[0094] The iron core 3I has a pair of legs 32A, 32B, a connecting portion 33A magnetically coupled to one end of each of the legs 32A, 32B, and a connecting portion 33B magnetically coupled to the other end of each of the legs 32A, 32B. The pair of coils 2A, 2B are attached to the pair of legs 32A, 32B of the iron core 3I, respectively.

[0095] In this embodiment, one of the pair of U-shaped cores 3Ub is divided into one I-shaped core 3Ic and a pair of I-shaped cores 3Ig.

[0096] A portion 32AA of one leg 32A, a portion 32BA of the other leg 32B, and one connecting portion 33A are formed of a U-shaped iron core 3Ub, another portion 32AB of one leg 32A of the iron core 3I and another portion 32BB of the other leg 32B are each formed of an I-shaped iron core 3Ig, and the other connecting portion 33B of the iron core 3I is formed of an I-shaped iron core 3Ic.

[0097] Both end faces of the U-core 3Ub are vertical end faces 32AAp, 32BAp. Vertical gaps 30pd are formed between the vertical end faces 32AAp, 32BAp of the U-core 3Ub and the vertical end faces 32ABp, 32BBp of each I-core 3Ig. In addition, inclined gaps 30s are formed between the inclined end faces 33Bs, 33Bs of the I-core 3Ic and the inclined end faces 32As, 32Bs of each I-core 3Ig.

[0098] While the first to ninth embodiments described above are configured such that a single coil 2 is attached to the center leg 32 of the approximately eight-shaped core 3, 3A to 3H, this embodiment is configured such that a pair of coils 2 are respectively attached to a pair of legs 32A, 32B (corresponding to the outer legs 32A, 32B in the first to ninth embodiments) of a square-shaped core 3I. As in this embodiment, the core may be configured without having a center leg 32. Also, as in this embodiment, two or more coils 2 may be attached to the core.

[0099] Also, as in this embodiment, a vertical gap 30pd may be provided in the legs 32A and 32B (or the outer legs), and the vertical gap 30pd may be accommodated in the hollow portion of the coil 2. This configuration reduces leakage of magnetic flux from the vertical gap 30pd. Also, this configuration blocks noise that may occur in the vertical gap 30pd by the coil 2, reducing the noise level.

[0100] The square-shaped iron core 3I of this embodiment forms a single square-shaped closed magnetic circuit as a whole. The ratio X / G of the sum of the lengths X of the inclined gaps 30s to the sum of the lengths G of the vertical gaps 30pd formed in the square-shaped closed magnetic circuit (i.e., in the square-shaped iron core 3I) is preferably 0.33 or more. Also, the value of X / G is preferably 3 or less.

[0101] <Eleventh embodiment> 17 is a front view of a reactor 1J according to an eleventh embodiment of the present invention. The reactor 1J according to this embodiment differs from the reactor 1I according to the tenth embodiment only in the position where the inclined gap 30s is provided in the iron core 3J, and therefore a duplicated description will be omitted.

[0102] In this embodiment, each of the pair of U-shaped cores 3Ub is divided into one L-shaped core 3La and one I-shaped core 3Ig.

[0103] One end face of the pair of L-shaped cores 3La is a vertical end face 32ABp, 32BAp, and the other end face is an inclined end face 33As, 33Bs. A vertical gap 30pd is formed between the vertical end face 32ABp, 32BAp of each L-shaped core 3La and the vertical end face 32AAp, 32BBp of each I-shaped core 3Ig. Also, an inclined gap 30s is formed between the inclined end face 33As, 33Bs of each L-shaped core 3La and the inclined end face 32As, 32Bs of each I-shaped core 3Ig.

[0104] In the above-described tenth embodiment, two inclined gaps 30s are provided at both ends in the longitudinal direction of one of the connecting portions 33B of the core 3I, but as in this embodiment, two inclined gaps 30s may be provided at diagonals of the core 3J. With this configuration, a more uniform magnetic flux density distribution is obtained than with the core 3I of the tenth embodiment, improving the inductance.

[0105] <Twelfth embodiment> 18 is a front view of a reactor 1K according to a twelfth embodiment of the present invention. The reactor 1K according to this embodiment differs from the reactors 1I and 1J according to the tenth and eleventh embodiments only in the number and positions of the inclined gaps 30s provided in the iron core 3K, and therefore a duplicated description will be omitted.

[0106] In this embodiment, each of the pair of U-shaped cores 3Ub is divided into one I-shaped core 3Ic and two I-shaped cores 3Ig. An inclined gap 30s is formed between the inclined end faces 33As and 33As of the I-shaped core 3Ic constituting the connecting portion 33A and the inclined end face 32As of the I-shaped core 3Ig constituting the part 32AA of the leg 32A and the inclined end face 32Bs of the I-shaped core 3Ig constituting the part 32BA of the leg 32B, and between the inclined end faces 33Bs and 33Bs of the I-shaped core 3Ic constituting the connecting portion 33B and the inclined end face 32As of the I-shaped core 3Ig constituting the other part 32AB of the leg 32A and the inclined end face 32Bs of the I-shaped core 3Ig constituting the other part 32BB of the leg 32B.

[0107] In the iron core 3I of the tenth embodiment and the iron core 3J of the eleventh embodiment described above, the inclined gaps 30s are provided at two corners of the square-shaped iron core, but the inclined gaps 30s may be provided at all four corners of the iron core 3K as in this embodiment. By providing the inclined gaps 30s at all corners of the iron core 3K, the decrease in magnetic flux density that occurs at the corners of the iron core is further mitigated, and a more uniform magnetic flux density distribution is obtained, further improving the inductance.

[0108] Although the above is a description of the embodiments of the present invention, the present invention is not limited to the configurations of the above embodiments, and various modifications are possible within the scope of the technical idea. For example, an appropriate combination of at least a part of the technical configurations of one or more embodiments described in the specification with a well-known technical configuration is also included in the embodiments of the present invention.

[0109] In each of the above embodiments, a vertical gap is provided in the middle leg portion 31 or the outer leg portion 32 (or between the middle leg portion 31 or the outer leg portion 32 and the connecting portion 33), but a vertical gap may also be provided in the connecting portion 33.

[0110] In the seventh to twelfth embodiments (FIGS. 13 to 18) described above, the multiple vertical gaps provided in each magnetic path of the core have the same gap length, but some or all of the multiple vertical gaps may have different gap lengths. However, when multiple magnetic paths are formed in the core, it is desirable that the total gap length of the vertical gaps in each magnetic path is the same value. For example, when the coil 2 is attached to the center leg 31 of the core 3G of the eighth embodiment (FIG. 14), even if the gap length of one vertical gap 30pa is made large and the gap length of the other vertical gap 30pa is made small, it is sufficient that the gap lengths of the four vertical gaps 30pc are the same. In this case, too, the total gap lengths of the vertical gaps 30p (30pa, 30pb, 30pc) in the two magnetic paths formed in the core 3G are the same. Furthermore, for example, when the coil 2 is attached to the center leg 31 of the iron core 3H of the ninth embodiment (FIG. 15), the gap length of the vertical gap 30pb may be increased and the gap length of the vertical gap 30pd may be decreased as long as the gap lengths of the two vertical gaps 30pd are the same. In this case as well, the total gap lengths of the vertical gaps 30p (30pb, 30pd, 30pd) in the two magnetic paths formed in the iron core 3H are the same.

[0111] In the above first to ninth embodiments, a configuration is adopted in which one iron core is attached to the center leg 31, but a pair of iron cores may be attached to each of the pair of outer legs 32. Also, a configuration in which an iron core is attached to the center leg 31 and all of the pair of outer legs 32 may be used. Also, a configuration in which an iron core is provided with a plurality of center legs 31. In this case, a configuration in which an iron core is attached to at least one of the center legs 31, or a configuration in which an iron core is attached only to the outer legs 32 may be used.

[0112] In each of the above-described embodiments, since the outer leg 32 and the connecting portion 33 have the same width (i.e., the horizontal length perpendicular to the length direction in the front view), the inclined gap 30s is formed at an inclination angle of 45° with respect to the length direction of the outer leg 32 and the connecting portion 33. However, the present invention is not limited to this configuration, and the inclined gap 30s may be formed at an inclination angle of, for example, 20°, 30°, 40°, 50°, 60°, 70° or other angles with respect to the length direction of the outer leg 32. As shown in FIG. 2, the inclined gap 30s is formed at the corner C of the frame-shaped portion. A Inside corner C i and corner C o Since the inclination angle of the inclined gap 30s is formed to connect the outer leg portion 32 and the connecting portion 33, the inclination angle of the inclined gap 30s changes depending on the relationship between the thicknesses of the outer leg portion 32 and the connecting portion 33.

[0113] The cores 3, 3A to 3E in each of the above embodiments are examples in which the present invention is applied to a laminated magnetic core, but the present invention can also be applied to magnetic cores made of other materials (e.g., powder magnetic cores, ferrite magnetic cores, amorphous metal cores, metal composite cores formed from resin containing magnetic particles, etc.).

[0114] The iron cores 3, 3A to 3E in each of the above embodiments are eight-shaped (single-sided) iron cores having one center leg 31 and two outer legs 32A, 32B, but may have other shapes (for example, one having two or more center legs, one having a cylindrical center leg, etc.).

[0115] In the above embodiment, the present invention is applied to a reactor, but the present invention is not limited to this configuration, and the present invention can be applied to various inductors such as transformers and choke coils. [Explanation of symbols]

[0116] 1 Reactor 2 Coil 3, 3A~3K Iron core 31 Middle leg 32 External legs 33 Connecting part 30p Vertical Gap 30s Slope Gap C A Corner C i Inside corner C o Corner G Gap length of vertical gap X Gap length of the inclined gap

Claims

1. A plurality of legs; a pair of coupling portions that magnetically couple one end portion and the other end portion of the plurality of legs in a longitudinal direction; having A vertical gap, which is a magnetic gap perpendicular to the length direction, is formed in at least one of the plurality of legs and the pair of connecting portions, the plurality of legs include a pair of outer legs that magnetically couple one end portion and the other end portion of the pair of connecting portions in a longitudinal direction, a frame-shaped portion is formed by the pair of outer legs and the pair of connecting portions, At least one corner of the frame-shaped portion is formed with an inclined gap, which is a magnetic gap connecting an inside corner and an outside corner. core.

2. One end surface of one of the connecting portions is a first inclined end surface inclined with respect to a longitudinal direction of the connecting portion, one end surface of the outer leg portion is a second inclined end surface inclined with respect to a longitudinal direction of the outer leg portion, The inclined gap is formed in a gap between the first inclined end surface and the second inclined end surface.

2. The magnetic core according to claim 1.

3. Two of the inclined gaps are formed in the frame-shaped portion, The inclined gap is formed adjacent to both ends of one of the connecting portions.

2. The magnetic core according to claim 1.

4. Two of the inclined gaps are formed in the frame-shaped portion, The inclined gap is formed adjacent to one end of one of the connecting portions and adjacent to the other end of the other connecting portion.

2. The magnetic core according to claim 1.

5. The inclined gaps are formed at the four corners of the frame-shaped portion.

2. The magnetic core according to claim 1.

6. The vertical gap is formed between one end of at least one of the legs and one of the connecting portions.

2. The magnetic core according to claim 1.

7. The vertical gap is formed between the other end of at least one of the legs and the other connecting portion.

7. The magnetic core according to claim 6.

8. The vertical gap is formed at a midpoint in the length direction of at least one of the legs.

2. The magnetic core according to claim 1.

9. a closed magnetic circuit is formed by the pair of outer legs and the pair of connecting portions, a ratio X / G of a sum of lengths X of the inclined gaps to a sum of lengths G of the vertical gaps formed in the closed magnetic circuit is 0.33 or more; 2. The magnetic core according to claim 1.

10. a closed magnetic circuit is formed by the pair of outer legs and the pair of connecting portions, a ratio X / G of a sum of lengths X of the inclined gaps to a sum of lengths G of the vertical gaps formed in the closed magnetic circuit is 3 or less; 2. The magnetic core according to claim 1.

11. The plurality of legs includes a middle leg disposed between the pair of outer legs. A magnetic core according to any one of claims 1 to 8.

12. a closed magnetic circuit is formed by the middle leg portion, one of the outer legs, and the pair of connecting portions, a ratio X / G of a sum of lengths X of the inclined gaps to a sum of lengths G of the vertical gaps formed in the closed magnetic circuit is 0.33 or more; 12. A magnetic core according to claim 11.

13. a closed magnetic circuit is formed by the middle leg portion, one of the outer legs, and the pair of connecting portions, a ratio X / G of a sum of lengths X of the inclined gaps to a sum of lengths G of the vertical gaps formed in the closed magnetic circuit is 3 or less; 12. A magnetic core according to claim 11.

14. a first closed magnetic circuit is formed by the middle leg portion, one of the outer legs, and the pair of connecting portions, a second closed magnetic circuit is formed by the middle leg portion, the other outer leg portion, and the pair of connecting portions, The sum of the lengths X of the inclined gaps formed in the first closed magnetic path is equal to the sum of the lengths X of the inclined gaps formed in the second closed magnetic path.

12. A magnetic core according to claim 11.

15. A magnetic core according to any one of claims 1 to 10; a winding attached to any one of the plurality of legs; A coil device comprising:

16. A magnetic core according to claim 11; a winding attached to any one of the plurality of legs; A coil device comprising:

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