Magnetic core and coil device

Abstract

The invention provides a magnetic core and a coil device, which can realize the improvement of inductance or the miniaturization of a coil. A magnetic core according to one embodiment of the present invention has a plurality of leg sections and a pair of connecting sections that magnetically connect one end section and the other end section of the plurality of leg sections 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 leg sections and the pair of connecting sections. The leg parts include a pair of outer leg parts which magnetically connect one end part and the other end part in the length direction of the pair of connecting parts, a frame-shaped part is formed by the pair of outer leg parts and the pair of connecting parts, and at least one corner part of the frame-shaped part is provided with an inclined gap which is a magnetic gap for joining an inner corner and an outer corner.

Description

Technical Field

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

[0002] Among coil devices such as reactors including magnetic cores, devices including gapped magnetic cores are known. A reactor including a gapped magnetic core is described in Patent Document 1. 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.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2020-68348 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, if a conventional gap core is used that forms only a magnetic gap perpendicular to the magnetic path as described in Patent Document 1, a portion with low magnetic flux density will be generated at the corner of the core. That is, in the conventional gap core, the performance of the magnetic material is not fully utilized, and there is room for improvement in inductance or miniaturization.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to improve the inductance of a magnetic core or to reduce its size.

[0010] [Technical means to solve the problem]

[0011] A magnetic core of one embodiment of the present invention comprises: a plurality of legs; and a pair of connecting portions, which magnetically connect one end portions and the other end portions of the plurality of legs in the length direction to each other, respectively; a magnetic gap perpendicular to the length direction, i.e., a vertical gap, 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 external legs, which magnetically connect one end portions and the other end portions of the pair of connecting portions in the length direction to each other, respectively; a frame-shaped portion is formed by the pair of external legs and the pair of connecting portions; a magnetic gap, i.e., an inclined gap, which connects an inner corner and an outer corner is formed in at least one corner of the frame-shaped portion.

[0012] In the magnetic core, the following structure can also be set: one end face of one connecting part is a first inclined end face inclined relative to the length direction of the connecting part, one end face of one outer leg part is a second inclined end face inclined relative to the length direction of the outer leg part, and an inclined gap is formed in the interval sandwiched by the first inclined end face and the second inclined end face.

[0013] 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 both end portions of one of the connecting portions.

[0014] 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 of the connecting portions and the other end of the other connecting portion.

[0015] The magnetic core may be configured such that inclined gaps are formed at four corners of the frame-shaped portion.

[0016] The magnetic core may be configured such that a vertical gap is formed between at least one end portion of the leg portion and one of the connecting portions.

[0017] The magnetic core may be configured such that a vertical gap is formed between at least one other end portion of the leg portion and the other connecting portion.

[0018] The magnetic core may be configured such that a vertical gap is formed in a middle portion of at least one of the leg portions in a longitudinal direction.

[0019] The structure may be such that a closed magnetic circuit is formed by a pair of outer legs and a pair of connecting portions, and a ratio X / G of the sum of the lengths X of the inclined gaps formed in the closed magnetic circuit to the sum of the lengths G of the vertical gaps is greater than 0.33.

[0020] The magnetic core may be configured such that a closed magnetic circuit is formed by a pair of outer legs and a pair of connecting portions, and a ratio X / G of the sum of the lengths X of the inclined gaps formed in the closed magnetic circuit to the sum of the lengths G of the vertical gaps is 3 or less.

[0021] In the magnetic core, the plurality of legs may include a middle leg disposed between a pair of outer legs.

[0022] In the magnetic core, the structure may be as follows: a closed magnetic circuit is formed by a middle leg, an outer leg and a pair of connecting parts, and the ratio X / G of the sum of the lengths X of the inclined gaps formed in the closed magnetic circuit to the sum of the lengths G of the vertical gaps is greater than 0.33.

[0023] In the magnetic core, the structure may be as follows: a closed magnetic circuit is formed by a middle leg, an outer leg and a pair of connecting parts, and the ratio X / G of the sum of the lengths X of the inclined gaps formed in the closed magnetic circuit to the sum of the lengths G of the vertical gaps is less than 3.

[0024] In the magnetic core, the following structure can also be adopted: a first closed magnetic circuit is formed by a middle leg, one of the outer legs and a pair of connecting portions; a second closed magnetic circuit is formed by the middle leg, another outer leg and a pair of connecting portions; and the sum of the lengths X of the inclined gaps formed in the first closed magnetic circuit is equal to the sum of the lengths X of the inclined gaps formed in the second closed magnetic circuit.

[0025] According to an embodiment of the present invention, there is provided a coil device including the magnetic core and a winding mounted on any one of a plurality of legs.

[0026] [Effects of the Invention]

[0027] According to one embodiment of the present invention, it is possible to improve the inductance of a coil device or to reduce the size of the coil device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is an external view of the reactor according to the first embodiment of the present invention.

[0029] Figure 2 It is a front view of the iron core according to the first embodiment of the present invention.

[0030] Figure 3 It is a figure which shows the dimension of the iron core which concerns on 1st Embodiment of this invention.

[0031] Figure 4 It is a diagram showing the simulation results of the magnetic flux density distribution of the conventional EI type core.

[0032] Figure 5 It is a diagram showing the simulation results of the magnetic flux density distribution of the iron core according to the first embodiment of the present invention.

[0033] Figure 6 This is a graph showing the DC superposition characteristics of the coil device according to the first embodiment of the present invention.

[0034] Figure 7 It is a front view of the iron core according to the second embodiment of the present invention.

[0035] Figure 8 It is a front view of the core according to the third embodiment of the present invention.

[0036] Fig. 9 It is a front view of the core according to the fourth embodiment of the present invention.

[0037] Fig.10 It is a front view of the core according to the fifth embodiment of the present invention.

[0038] Fig.11 It is a front view of an iron core according to a sixth embodiment of the present invention.

[0039] Fig.12 It is a front view of the core according to the seventh embodiment of the present invention.

[0040] Fig.13 It is a diagram showing a closed magnetic circuit formed on an iron core according to a seventh embodiment of the present invention.

[0041] Fig.14 It is a front view of an iron core according to an eighth embodiment of the present invention.

[0042] Fig.15 It is a front view of the core according to the ninth embodiment of the present invention.

[0043] Fig.16 It is a front view of an iron core according to a tenth embodiment of the present invention.

[0044] Fig.17 It is a front view of an iron core according to an eleventh embodiment of the present invention.

[0045] Fig.18 It is a front view of the core according to the twelfth embodiment of the present invention.

[0046] [Explanation of Symbols]

[0047] 1: Reactor

[0048] 2: Coil

[0049] 3. 3A~3K: Iron core

[0050] 31: Midfoot

[0051] 32: Outer foot

[0052] 33: Connection

[0053] 30p: Vertical Gap

[0054] 30s: Tilt gap

[0055] C A : Corner

[0056] C i :Inner angle

[0057] C o : outer corner

[0058] G: Gap length of the vertical gap

[0059] X: Gap length of the inclined gap DETAILED DESCRIPTION

[0060] Hereinafter, the embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in the following description, the same or corresponding items are marked with the same or corresponding symbols, and repeated descriptions are omitted. In addition, in each figure, when multiple symbols are displayed to show items common to multiple symbols, it is not necessary to mark all of these multiple displays with symbols, and the assignment of symbols is appropriately omitted for a part of these multiple displays.

[0061] <First embodiment>

[0062] Figure 1 1 is an appearance diagram 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). The components constituting the coil 2 and the iron core 3 (an I-shaped iron core 3Ia, a T-shaped iron core 3Ta, and a pair of I-shaped iron cores 3Ib described later) are held (i.e., their relative positions are fixed) by a holding member (not shown) such as an insulating bobbin, for example.

[0063] In addition, in the following description, Figure 1 The direction from the upper left to the lower right is defined as the X direction, the direction from the lower left to the upper right is defined as the Y direction, and the direction from the bottom to the top is defined as the Z direction. The X direction, the Y direction, and the Z direction are mutually orthogonal directions. In addition, the reactor 1 can be used in a state where any direction among the X direction, the Y direction, the Z direction, and the direction in between is oriented vertically. In addition, in the following description, for the sake of convenience, the X direction is sometimes referred to as the width direction or the left-right direction, the Y direction is referred to as the depth direction or the front-back direction, and the Z direction is referred to as the height direction or the up-down direction.

[0064] The coil 2 is a coil formed by winding an insulating wire such as an enameled wire in a spiral shape. As the material of the wire, copper or aluminum can be used, for example. The coil 2 is a coil formed by winding a flat wire in a flat manner, but it can also be a coil of other winding methods, or a coil formed of a round wire or a stranded wire. In addition, the coil 2 can also be formed of a conductor in the form of a foil or a strip, such as a copper foil coil or a copper strip coil.

[0065] Figure 2 1 is a front view of the iron core 3 of the first embodiment of the present invention. The iron core 3 is a substantially eight-shaped (or square-shaped) member assembled from an I-shaped iron core 3Ia, a T-shaped iron core 3Ta, and a pair of I-shaped iron cores 3Ib. The I-shaped iron core 3Ia, the T-shaped iron core 3Ta, and the I-shaped iron core 3Ib are laminated iron 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.

[0066] The core 3 includes: a middle leg 31, on which the coil 2 is mounted (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 middle leg 31; and a pair of connecting portions 33 connecting the middle leg 31 and the pair of outer legs 32. The connecting portion 33 includes: a connecting portion 33A (first yoke) connected to the middle leg 31 and one end of the pair of outer legs 32A, 32B (at Figure 2 and the connecting portion 33B (second yoke), and the middle leg portion 31 and a pair of outer leg portions 32A, 32B of the other end (in Figure 2 The connecting portion 33A magnetically connects one end of the plurality of legs (middle leg 31, outer leg 32A, outer leg 32B) in the length direction to each other, and the connecting portion 33B magnetically connects the other end of the plurality of legs to each other. A frame-shaped portion is formed by a pair of outer legs 32A, 32B and a pair of connecting portions 33A, 33B. In addition, the "middle leg" and the "outer leg" are collectively referred to as "legs".

[0067] In this embodiment, the middle leg portion 31 and the connecting portion 33B are composed of a T-shaped iron core 3Ta, the pair of outer legs 32A, 32B are respectively composed of a pair of I-shaped iron cores 3Ib, 3Ib, and the connecting portion 33A is composed of an I-shaped iron core 3Ia.

[0068] One end face of the outer leg 32A, 32B in the length direction (Z direction) is formed into an inclined end face 32As and an inclined end face 32Bs inclined at 45° relative to the Z direction. In addition, both end faces in the length direction (X direction) of the connecting portion 33B are also formed into an inclined end face 33Bs and an inclined end face 33Bs inclined at 45° relative to the X direction (that is, also inclined at 45° relative to the Z direction). An inclined gap 30s serving as a magnetic gap is formed between the inclined end faces 32As and 32Bs of the outer leg 32A, 32B and the inclined end faces 33Bs and 33Bs of the connecting portion 33B. In the present embodiment, the two inclined gaps 30s have the same gap length (the length of the inclined gap 30s in the direction perpendicular to the inclined end faces 32As and 32Bs).

[0069] The corner C of the frame-shaped portion is formed by one end of the wedge shape of the outer leg portion 32A having the inclined end surface 32As and one end of the wedge shape of the connecting portion 33B having the inclined end surface 33Bs. A . Tilt the gap 30s to make the corner C A interior angle C i (That is, the corner C A The inner angle) and the outer angle C o (That is, the corner C A The outer corners of the tube are connected in a manner that forms a junction.

[0070] The corner C of the frame-shaped portion is formed by one end of the wedge-shaped outer leg portion 32B having the inclined end surface 32Bs and the other end of the wedge-shaped connecting portion 33B having the inclined end surface 33Bs. B . Tilt the gap 30s to make the corner C B interior angle C i With external angle C o It is formed by a tandem method.

[0071] The end face of the middle leg portion 31 is a vertical end face 31p that is perpendicular to the longitudinal direction (Z direction) of the middle leg portion 31. A vertical gap 30pa (30p) serving as a magnetic gap is formed between the vertical end face 31p of the middle leg portion 31 and the side face of the connecting portion 33A. In addition, the inclined gap 30s and the vertical gap 30pa are formed perpendicularly to the ZX plane.

[0072] In addition, the inclined gap 30s and the vertical gap 30pa of the present embodiment are air gaps, but a gap plate formed of a non-magnetic resin or ceramic can be inserted between the inclined end faces or between the vertical end faces to form a magnetic gap. In addition, the magnetic gap can also be formed by filling the inclined end faces or between the vertical end faces with an adhesive or a thermosetting resin and hardening them.

[0073] Computer simulation was performed on the characteristics of the reactor 1 according to the first embodiment of the present invention. Figure 3 : is a figure which shows the dimension of the model of the iron core 3 used in the computer-simulation. In addition, the depth d (Y direction) of the iron core 3 is 65 mm. In addition, the winding number of the coil 2 is set to 105 turns.

[0074] [Table 1]

[0075] No. title G[mm] X[mm] X / G <![CDATA[ΔL 13 A [mH]]]> <h2 style=";text-align:left;direction:ltr"><![CDATA[L <h2 style=";text-align:left;direction:ltr"> 13 <h2 style=";text-align:left;direction:ltr"> A <h2 style=";text-align:left;direction:ltr"> / L2<h2 style=";text-align:left;direction:ltr"> A <h2 style=";text-align:left;direction:ltr"> ]]><h2 style=";text-align:left;direction:ltr"> M1 G1.6 1.6 0 0 - 0.954 M2 G1.4+X0.2 1.4 0.2 0.14 -0.24％ 0.966 M3 G1.2+X0.4 1.2 0.4 0.33 0.29％ 0.968 M4 G1.1+X0.5 1.1 0.5 0.45 0.91％ 0.969 M5 G1.0+X0.6 1.0 0.6 0.60 1.64％ 0.965 M6 G0.8+X0.8 0.8 0.8 1.00 3.90％ 0.956 M7 G0.6+X1.0 0.6 1.0 1.67 7.16％ 0.938 M8 G0.4+X1.2 0.4 1.2 3.00 11.07％ 0.912 M9 G0.3+X1.3 0.3 1.3 4.33 13.45％ 0.894 M10 G0.2+X1.4 0.2 1.4 7.00 16.45％ 0.871 M11 X1.6 0 1.6 - 23.64％ 0.814

[0076] Table 1 shows the dimensions (G, X, X / G) of the vertical gap 30pa and the inclined gap 30s in each model of the core 3 used in the computer simulation, and the Figure 6 The index (ΔL 13 A 、L2 A / L 13 A ). 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 value of the ratio of the gap length X of the inclined gap 30s to the gap length G of the vertical gap 30pa.

[0077] 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 is a comparative example (prior art), and models M2 to M11 are examples of the present embodiment. In order to make the gap length consistent within the magnetic circuit, the sum of the gap length G and the gap length X is set to a certain value (1.6 mm). In addition, model M1 (X=0 mm) is a model (comparative example) equivalent to an existing EI-shaped magnetic core that does not have an inclined gap 30s. In addition, model M11 (G=0 mm) is a model equivalent to a magnetic core that does not have a vertical gap 30pa (i.e., the vertical end face 31p of the middle leg 31 is in close contact or engagement with the side of the connecting portion 33A).

[0078] Figure 4 and Figure 5 : is a diagram showing the magnetic flux density distribution of the reactor 1 obtained by computer-simulation. Figure 4 is the magnetic flux density distribution diagram of model M1 (comparative example), Figure 5 is the magnetic flux density distribution diagram of model M5 (embodiment). Figure 4 and Figure 5 In the figure, except for the outline, the higher the brightness (brighter), the higher the magnetic flux density. Figure 4 In the conventional EI-shaped core (model M1) shown in FIG. 1 , portions with low magnetic flux density are generated at both ends and the center of the connecting portion 33A and the connecting portion 33B in the longitudinal direction. Figure 5 In the embodiment of the present invention (model M5) shown in FIG. 1 , the decrease in magnetic flux density is alleviated as a whole, and in particular, the decrease in magnetic flux density is substantially eliminated near the inclined gap 30s. Figure 4 and Figure 5 It is understood that the magnetic flux density of the core 3 is made uniform by introducing the inclined gap 30s into the core 3 .

[0079] Figure 6 is a graph showing the DC superposition characteristics of the reactor 1 obtained by computer-simulation. Figure 6 In the graph, the horizontal axis represents effective current [A] and the vertical axis represents inductance [mH].

[0080] Table 1 "ΔL 13 A ” and “L2 A / L 13 A " is based on Figure 6 The DC superposition characteristic shown in the graph is calculated based on the simulation result of the DC superposition characteristic. 13 A " is an index showing the rate of increase in inductance from the conventional EI core (model M1), "L13 A / L2 A ” is an indicator of the stability of inductance relative to changes in effective current.

[0081] Specifically, "ΔL 13 A " is the rate of increase of inductance based on the inductance of the reactor 1 using the conventional EI core (model M1) when an effective current of 13 A flows, and is calculated by the following formula (1).

[0082]

[0083] Here, "L Mn (13A)" is the inductance of the reactor 1 of the core 3 using the model Mn (wherein "n" is an integer of 1 to 11) when an effective current of 13A flows.

[0084] In addition, "L 13 A / L2 A " is the inductance L2 when the effective current of 2A flows A The inductance L when the effective current of 13A flows is based on 13 A The relative size of 13 A / L2 A The larger the value of " is (i.e., closer to 1), the less the variation (drop) of inductance in the common region of effective current (e.g., 2A to 13A) is, and the inductance characteristic is stable.

[0085] 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), improvement in inductance compared to the conventional EI core (model M1) is confirmed.

[0086] In addition, regarding the reactor, it is easier to use when the inductance L is stable with respect to the change of the current, and the change range (drop range) of the inductance L in the common range of the effective current (for example, 2A to 13A) is preferably within about 10%. According to Table 1, for the 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 representing the change rate of the inductance L in the common range of the effective current (2A to 13A), i.e., "L 13 A / L2 A ” is greater than 0.9 (i.e., the fluctuation range is less than 10%), and stable inductance characteristics in the normal range of effective current are confirmed.

[0087] In addition, the number or position of the inclined gap 30s and the vertical gap 30pa is not limited to the structure of the first embodiment. Other embodiments in which the number or position of the inclined gap 30s and the vertical gap 30p are different are exemplified below. In the second to ninth embodiments of the present invention to be described below, only the structure of the core 3A to the core 3H described later (particularly the number and position of the inclined gap 30s and the vertical gap 30p) is different from the structure of the first embodiment.

[0088] <Second embodiment>

[0089] Figure 7 1 is a front view of an iron core 3A according to a second embodiment of the present invention. The iron core 3A is a substantially figure-eight (or square-S) shaped laminated iron core assembled from one U-shaped iron core 3Ua and one T-shaped iron core 3Ta.

[0090] In this embodiment, the middle leg 31 and the connecting portion 33B are formed by a T-shaped core 3Tb, and the outer leg 32A, the outer leg 32B and the connecting portion 33A are formed by a U-shaped core 3Ua. The two end faces of the U-shaped core 3Ua are inclined end faces 32As and inclined end faces 32Bs.

[0091] In the iron core 3 of the first embodiment, three I-shaped iron cores 3Ia, 3Ib and 3Ib are joined to form a U-shaped (or U-shaped) iron core, but in the present embodiment, by using a U-shaped iron core 3Ua, the number of parts can be reduced, and there is no need for the process of joining the three I-shaped iron cores 3Ia, 3Ib and 3Ib, thereby reducing the manufacturing cost of the iron core.

[0092] <Third embodiment>

[0093] Figure 8 1 is a front view of an iron core 3B according to a third embodiment of the present invention. The iron core 3B is a substantially figure-eight (or square-S) shaped laminated iron core assembled from an E-shaped iron core 3Ea and a T-shaped iron core 3Tb.

[0094] In this embodiment, a portion 31A of the middle leg 31, a pair of outer legs 32A, 32B, and a connecting portion 33A are formed by an E-shaped core 3Ea, and the remaining portion 31B of the middle leg 31 and the connecting portion 33B are formed by a T-shaped core 3Tb.

[0095] One end surface of the outer leg 32A, 32B in the length direction (Z direction) is an inclined end surface 32As, an inclined end surface 32Bs inclined at 45° with respect to the Z direction. In addition, both end surfaces of the connecting portion 33B in the length direction (X direction) are also inclined end surfaces 33Bs, an inclined end surface 33Bs inclined at 45° with respect to the X direction. An inclined gap 30s is formed between the inclined end surfaces 32As, 32Bs of the outer leg 32A, 32B and the inclined end surfaces 33Bs, 33Bs of the connecting portion 33B. The two inclined gaps 30s have the same gap length.

[0096] One end face of each part 31A, 31B of the middle leg 31 in the longitudinal direction (Z direction) is a vertical end face 31Ap and a vertical end face 31Bp perpendicular to the Z direction. A vertical gap 30pb (30p) is formed between the vertical end faces 31Ap and the vertical end faces 31Bp of each part 31A, 31B of the middle leg 31.

[0097] As in the present embodiment, a vertical gap 30pb may be provided in the middle portion in the longitudinal direction of the middle leg portion 31. In the present embodiment, the lengths of the portions 31A and 31B of the middle leg portion 31 are equal, but they may be different in length.

[0098] <Fourth embodiment>

[0099] Fig. 9 1 is a front view of an iron core 3C according to a fourth embodiment of the present invention. The iron core 3C is a substantially figure-eight (or square-S) shaped laminated iron core assembled from an E-shaped iron core 3Eb and an I-shaped iron core 3Ic.

[0100] In the present embodiment, the middle leg portion 31, the pair of outer leg portions 32A, 32B, and the connecting portion 33A are formed by an E-shaped iron core 3Eb, and the connecting portion 33B is formed by an I-shaped iron core 31c.

[0101] One end surface of the outer leg 32A, 32B in the length direction (Z direction) is an inclined end surface 32As, an inclined end surface 32Bs inclined at 45° with respect to the Z direction. In addition, both end surfaces of the connecting portion 33B in the length direction (X direction) are also inclined end surfaces 33Bs, an inclined end surface 33Bs inclined at 45° with respect to the X direction. An inclined gap 30s is formed between the inclined end surfaces 32As, 32Bs of the outer leg 32A, 32B and the inclined end surfaces 33Bs, 33Bs of the connecting portion 33B. The two inclined gaps 30s have the same gap length.

[0102] The end surface of the middle leg portion 31 in the longitudinal direction (Z direction) is a vertical end surface 31p perpendicular to the Z direction. A vertical gap 30pa is formed between the vertical end surface 31p of the middle leg portion 31 and the side surface of the connecting portion 33B.

[0103] 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 the present embodiment, the vertical gap 30pa is provided between the connecting portion 33B and the middle leg portion 31. As in the present embodiment, the vertical gap 30pa and the inclined gap 30s may be provided at positions adjacent to the same connecting portion 33B (or the connecting portion 33A).

[0104] <Fifth embodiment>

[0105] Fig.10 1 is a front view of an iron core 3D according to a fifth embodiment of the present invention. The iron core 3D is a substantially figure-eight (or square-S)-shaped laminated iron core assembled from a pair of F-shaped iron cores 3Fa.

[0106] In this embodiment, a portion 31A of the middle leg 31, the outer leg 32A and the connecting portion 33A are formed by one of the F-shaped cores 3Fa, and the remaining portion 31B of the middle leg 31, the outer leg 32B and the connecting portion 33B are formed by the other F-shaped core 3Fa.

[0107] One end face of the outer leg 32A, 32B in the length direction (Z direction) is an inclined end face 32As, 32Bs inclined at 45° with respect to the Z direction. In addition, one end face of the connecting portion 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 face 32As, 32Bs of the outer leg 32A, 32B and the inclined end face 33Bs, 33As of the connecting portion 33B, 33A. The two inclined gaps 30s have the same gap length.

[0108] One end surface of the portion 31A and the portion 31B of the middle leg 31 in the longitudinal direction (Z direction) is a vertical end surface 31Ap and a vertical end surface 31Bp perpendicular to the Z direction. A vertical gap 30pb is formed between the vertical end surfaces 31Ap and 31Bp of the middle leg 31.

[0109] In the first to fourth embodiments, a pair of inclined gaps 30s, 30s are formed adjacent to both ends of one of the connecting portions 33B, but in the present embodiment, one inclined gap 30s is formed adjacent to one of the connecting portions 33A, and another inclined gap 30s is formed adjacent to the other connecting portion 33B. As in the present embodiment, the pair of inclined gaps 30s, 30s may be provided at the diagonal portions of the core (in other words, at positions adjacent to different outer leg portions 32 and different connecting portions 33, respectively).

[0110] <Sixth embodiment>

[0111] Fig.11 1 is a front view of an iron core 3E according to a sixth embodiment of the present invention. The iron core 3E is a substantially figure-eight (or square-S) shaped laminated iron core assembled from a pair of T-shaped iron cores 3Tb and a pair of I-shaped iron cores 3Id.

[0112] In this embodiment, a portion 31A of the middle leg 31 and the connecting portion 33A are composed of one of the T-shaped iron cores 3Tb, and the remaining portion 31B of the middle leg 31 and the connecting portion 33B are composed of another T-shaped iron core 3Tb, and the outer leg 32A and the outer leg 32B are respectively composed of an I-shaped iron core 3Id and an I-shaped iron core 3Id.

[0113] The two end faces of the outer leg 32A and the outer leg 32B in the length direction (Z direction) are inclined end faces 32As, 32As, 32Bs, and 32Bs, which are inclined at 45° with respect to the Z direction. In addition, the two end faces of the connecting portion 33A and the connecting portion 33B in the length direction (X direction) are also inclined end faces 33As, 33As, 33Bs, and 33Bs, which are inclined at 45° with respect to the X direction. Inclined gaps 30s are formed between one inclined end face 32As and one inclined end face 33As, between another inclined end face 32As and one inclined end face 33Bs, between one inclined end face 32Bs and another inclined end face 33As, and between another inclined end face 32Bs and another inclined end face 33Bs. The four inclined gaps 30s have the same gap length.

[0114] One end surface of the portion 31A and the portion 31B of the middle leg 31 in the longitudinal direction (Z direction) is a vertical end surface 31Ap and a vertical end surface 31Bp perpendicular to the Z direction. A vertical gap 30pb is formed between the vertical end surfaces 31Ap and 31Bp of the middle leg 31.

[0115] In the first to fifth embodiments, two inclined gaps 30s are provided on the core 3, the core 3A to the core 3D, but four inclined gaps 30s may be provided at the four corners of the core as in the present embodiment. In addition, an odd number (e.g., 1 or 3) of inclined gaps 30s may be provided on the core, but when the same number of inclined gaps 30s are provided in each closed magnetic circuit in the core, the distribution of the magnetic flux density is more uniform, thereby obtaining a higher inductance.

[0116] <Seventh embodiment>

[0117] Fig.121 is a front view of a core 3F according to a seventh embodiment of the present invention. The core 3F is a substantially figure-eight (or square-S) shaped laminated core assembled from a pair of I-shaped cores 31c, a pair of I-shaped cores 31d, and one I-shaped core 31e.

[0118] In this embodiment, the middle leg 31 is composed of an I-shaped iron core 3Ie, the outer leg 32A and the outer leg 32B are respectively composed of an I-shaped iron core 3Id and an I-shaped iron core 3Id, and the connecting portion 33A and the connecting portion 33B are respectively composed of an I-shaped iron core 3Ic and an I-shaped iron core 3Ic.

[0119] The two end faces of the outer leg 32A and the outer leg 32B in the length direction (Z direction) are inclined end faces 32As, 32As, 32Bs, and 32Bs, which are inclined at 45° with respect to the Z direction. In addition, the two end faces of the connecting portion 33A and the connecting portion 33B in the length direction (X direction) are also inclined end faces 33As, 33As, 33Bs, and 33Bs, which are inclined at 45° with respect to the X direction. Inclined gaps 30s are formed between one inclined end face 32As and one inclined end face 33As, between another inclined end face 32As and one inclined end face 33Bs, between one inclined end face 32Bs and another inclined end face 33As, and between another inclined end face 32Bs and another inclined end face 33Bs. The four inclined gaps 30s have the same gap length X.

[0120] The two end faces of the middle leg portion 31 in the length direction (Z direction) are vertical end faces 31p and 31p perpendicular to the Z direction. Vertical gaps 30pa and 30pa are formed between the vertical end faces 31p and 31p of the middle leg portion 31 and the side faces of the connecting portions 33A and 33B, respectively. The two vertical gaps 30pa have the same gap length X.

[0121] In the first to sixth embodiments, one vertical gap 30p (30pa, 30pb) is provided in the core 3 and the cores 3A to 3E. However, two vertical gaps 30p may be provided in the core as in the present embodiment.

[0122] like Fig.13As shown, two closed magnetic circuits (a first closed magnetic circuit P1 and a second closed magnetic circuit P2) are formed on the iron core 3F of the figure eight (sun-shaped) of the present embodiment. In order to make the magnetic flux density in the iron core 3F uniform and thus obtain a higher inductance, it is preferred to make the total of the gap length X and the gap length G of the magnetic gaps (inclined gaps 30s, vertical gaps 30p) contained in each closed magnetic circuit P1, P2 consistent. In addition, it is preferred to make the total of the gap length X of the inclined gaps 30s contained in each closed magnetic circuit P1, P2 consistent. In addition, it is preferred to make the total of the gap length G of the vertical gaps 30p contained in each closed magnetic circuit P1, P2 consistent. The same can also be said for the iron cores 3, 3A to 3H of the first to ninth embodiments of the same figure eight (sun-shaped) embodiment.

[0123] <Eighth Embodiment>

[0124] Fig.14 : This is a front view of the core 3G of the eighth embodiment of the present invention. The core 3G is a laminated core in a substantially figure-eight (or figure-seven) shape, which is assembled from a pair of I-shaped cores 3Ia, a pair of I-shaped cores 3If, and an I-shaped core 3Ie, and an inclined gap 30s shown by a dotted line is added to at least one of the four corners. In addition, it is desirable to provide the same number (2 or 4) of inclined gaps 30s on each closed magnetic circuit P1, P2 formed in the core 3G.

[0125] For example, when the inclined gaps 30s are provided at all four corners of the core 3G, each I-shaped core 31a is divided into one I-shaped core 31c 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 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. The 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-shaped core 31c.

[0126] In addition, a vertical gap 30 pc is formed between the vertical end faces 32Ap (or the inclined end faces 32Bp) formed at both ends in the longitudinal direction of each I-shaped core 3If and one of the vertical end faces 34p of the triangular core 34.

[0127] In this case, the middle leg 31 is composed of an I-shaped iron core 3Ie, the outer leg 32A and the outer leg 32B are respectively composed of an I-shaped iron core 3If and an I-shaped iron core 3If, and the connecting portion 33A and the connecting portion 33B are respectively composed of an I-shaped iron core 3Ic and two triangular iron cores 34.

[0128] The number of inclined gaps 30s provided in the core 3G is not limited to 4, and 1, 2 or 3 inclined gaps 30s may be provided at the corners of the core 3G. In addition, it is preferred that the same number (e.g., one or two) of inclined gaps 30s are provided in the two closed magnetic circuits of the core 3G.

[0129] In the first to seventh embodiments, a vertical gap 30p (30pa, 30pb) is provided only in the middle leg portion 31 (or between the middle leg portion 31 and the connecting portion 33A, the connecting portion 33B), but a vertical gap 30p (vertical gap 30pc in the present embodiment or vertical gap 30pd described later) may also be provided in the outer leg portion 32A, the outer leg portion 32B (or between the outer leg portion 32A, the outer leg portion 32B and the connecting portion 33A, the connecting portion 33B) as in the present embodiment.

[0130] In addition, as in the present embodiment, a plurality of vertical gaps 30p of three or more may be provided in the closed magnetic circuit. By increasing the number of vertical gaps 30p (in other words, reducing the X / G value), a stable inductance characteristic in a common region of effective current can be obtained. In addition, if the number of vertical gaps 30p is increased, the gap length of one vertical gap 30p can be shortened, thereby reducing the leakage flux in the vertical gap 30p.

[0131] <Ninth embodiment>

[0132] Fig.15 The core 3H is a front view of a ninth embodiment of the present invention. The core 3H is a substantially figure-eight (or square-S) shaped laminated core assembled from a pair of E-shaped cores 3Ec, with an inclined gap 30s indicated by a dotted line provided at least at one of the four corners.

[0133] For example, when the inclined gaps 30s are provided at all four corners of the core 3H, each E-shaped core 3Ec is divided into one T-shaped core 3Tb and two I-shaped cores 3Ig. In this case, the connecting portion 33A and a portion 31A of the middle leg 31 (or the connecting portion 33B and a portion 31B of the middle leg 31) are formed by the T-shaped core 3Tb, and the outer leg 32A, a portion 32AA of the outer leg 32B, a portion 32AB, a portion 32BA, and a portion 32BB are formed by the I-shaped core 3Ig.

[0134] The T-shaped core 3Tb has inclined end faces 33As (or inclined end faces 33Bs) formed at both ends in the X direction, and has a vertical end face 31Ap (or inclined end face 31Bp) formed at one end in the Z direction. In addition, the I-shaped core 3Ig (i.e., a portion 32AA or a portion 32AB of the outer leg 32A, or a portion 32BA or a portion 32BB of the outer leg 32B) has an inclined end face 32As or an inclined end face 32Bs formed at one end in the longitudinal direction (Z direction), and has a vertical end face 32AAp or a vertical end face 32ABp or a vertical end face 32BAp or a vertical end face 32BBp formed at the other end.

[0135] An inclined gap 30s is formed between the inclined end face 33As or the inclined end face 33Bs of the T-shaped core 3Tb and the inclined end face 32As or the inclined end face 32Bs of the I-shaped core 3Ig. The four inclined gaps 30s have the same gap length. In addition, a vertical gap 30pb is formed between the vertical end face 31Ap and the vertical end face 31Bp of a pair of T-shaped cores 3Tb.

[0136] In addition, a vertical gap 30pd is formed between a vertical end face 32AAp (or a vertical end face 32ABp) of the I-shaped iron core 3Ig constituting a portion 32AA of the outer leg 32A (or a portion 32BA of the outer leg 32B) and a vertical end face 32ABp of the I-shaped iron core 3Ig constituting another portion 32AB of the outer leg 32A (or another portion 32BB of the outer leg 32B). Each vertical gap 30pd has the same gap length. In addition, in the present embodiment, the vertical gap 30pb and the vertical gap 30pd also have the same gap length.

[0137] Alternatively, a structure in which one inclined gap 30s is provided in each E-shaped core 3Ec or a structure in which two inclined gaps 30s are provided in one E-shaped core 3Ec may be adopted.

[0138] When each E-shaped iron core 3Ec is provided with one inclined gap 30s, each E-shaped iron core 3Ec is divided into an F-shaped iron core 3Fb and an I-shaped iron core 3Ig. In this case, the connecting portion 33A, a portion 31A of the middle leg portion 31, and a portion 32AA of one outer leg portion 32A (or a portion 32BA of the outer leg portion 32B) are composed of the F-shaped iron core 3Fb, and a portion 32BA of the other outer leg portion 32B (or a portion 32AA of the outer leg portion 32A) is composed of the I-shaped iron core 3Ig. In addition, the connecting portion 33B, a portion 31B of the middle leg portion 31, and a portion 32AB of one outer leg portion 32A (or a portion 32BB of the outer leg portion 32B) are composed of the F-shaped iron core 3Fb, and a portion 32BB of the other outer leg portion 32B (or a portion 32AB of the outer leg portion 32A) is composed of the I-shaped iron core 3Ig.

[0139] An inclined gap 30s is formed between the inclined end face 33As (or the inclined end face 33Bs) of the F-shaped core 3Fb and the inclined end face 32As (or the inclined end face 32Bs) of the I-shaped core 3Ig. In addition, a vertical gap 30pd is formed between the vertical end face 32AAp of one F-shaped core 3Fb (or one I-shaped core 3Ig) and the vertical end face 32ABp of the other F-shaped core 3Fb (or the other I-shaped core 3Ig), and between the vertical end face 32BAp of one F-shaped core 3Fb (or one I-shaped core 3Ig) and the vertical end face 32BBp of the other F-shaped core 3Fb (or the other I-shaped core 3Ig). Furthermore, a vertical gap 30pb is formed between the vertical end face 31Ap of one F-shaped core 3Fb and the vertical end face 31Bp of the other F-shaped core 3Fb.

[0140] As in the present embodiment, vertical gaps 30pd may be provided at the longitudinal center (Z direction) of the middle leg 31 and the outer leg 32. By providing vertical gaps 30pb at the longitudinal center of the middle leg 31 and the outer leg 32, leakage flux in the vertical gaps can be reduced.

[0141] <Tenth embodiment>

[0142] Fig.16 1 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. Fig.16 , a cross section of the coil 2A and the coil 2B is shown. The core 3I is a stacked core in a square shape (or substantially O shape) assembled from a pair of U-shaped cores 3Ub, with inclined gaps 30s added at two diagonal corners.

[0143] The core 3I has a pair of legs 32A, 32B, a connection portion 33A magnetically coupled to one end of each leg 32A, 32B, and a connection portion 33B magnetically coupled to the other end of each leg 32A, 32B. A pair of coils 2A, 2B are attached to the pair of legs 32A, 32B of the core 3I, respectively.

[0144] In the present 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.

[0145] A portion 32AA of one leg 32A, a portion 32BA of the other leg 32B and one connecting portion 33A are composed 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 respectively composed of an I-shaped iron core 3Ig, and the other connecting portion 33B of the iron core 3I is composed of an I-shaped iron core 3Ic.

[0146] The two end faces of the U-shaped core 3Ub are respectively formed as vertical end faces 32AAp and vertical end faces 32BAp. A vertical gap 30pd is formed between each vertical end face 32AAp and 32BAp of the U-shaped core 3Ub and the vertical end face 32ABp and vertical end face 32BBp of each I-shaped core 3Ig. In addition, an inclined gap 30s is formed between each inclined end face 33Bs and 33Bs of the I-shaped core 3Ic and the inclined end face 32As and inclined end face 32Bs of each I-shaped core 3Ig.

[0147] In contrast to the structure in which a single coil 2 is mounted on the middle leg 32 of the roughly figure-eight iron core 3, iron core 3A to iron core 3H in the first to ninth embodiments, the present embodiment has a structure in which a pair of coils 2 are mounted on a pair of legs 32A and 32B (corresponding to the outer legs 32A and 32B in the first to ninth embodiments) of the figure-eight iron core 3I, respectively. It is also possible to have a structure in which the iron core does not have the middle leg 32 as in the present embodiment. In addition, it is also possible to have a structure in which two or more coils 2 are mounted on the iron core as in the present embodiment.

[0148] In addition, as in the present embodiment, a vertical gap 30pd may be provided on the leg 32A, the leg 32B (or the outer leg), and the vertical gap 30pd may be accommodated in the hollow portion of the coil 2. According to such a structure, the leakage of the magnetic flux from the vertical gap 30pd is alleviated. In addition, according to the above structure, the noise that may be generated in the vertical gap 30pd is shielded by the coil 2, and the noise level is alleviated.

[0149] The ?-shaped iron core 3I of this embodiment constitutes a ?-shaped closed magnetic circuit as a whole. The value of the ratio X / G of the sum of the lengths X of the inclined gaps 30s formed in the ?-shaped closed magnetic circuit (i.e., in the ?-shaped iron core 3I) and the sum of the lengths G of the vertical gaps 30pd is preferably 0.33 or more. In addition, the value of X / G is preferably 3 or less.

[0150] <Eleventh Embodiment>

[0151] Fig.171 is a front view of a reactor 1J according to an eleventh embodiment of the present invention. The reactor 1J of this embodiment differs from the reactor 1I of the tenth embodiment only in the position where the inclined gap 30s is provided in the iron core 3J, and therefore, duplicate descriptions are omitted.

[0152] In the present embodiment, each of the pair of U-shaped cores 3Ub is divided into one L-shaped core 3La and one I-shaped core 3Ig.

[0153] One end face of a pair of L-shaped cores 3La is formed into a vertical end face 32ABp and a vertical end face 32BAp, respectively, and the other end faces are formed into an inclined end face 33As and an inclined end face 33Bs, respectively. A vertical gap 30pd is formed between the vertical end face 32ABp and the vertical end face 32BAp of each L-shaped core 3La and the vertical end face 32AAp and the vertical end face 32BBp of each I-shaped core 3Ig. In addition, an inclined gap 30s is formed between the inclined end face 33As and the inclined end face 33Bs of each L-shaped core 3La and the inclined end face 32As and the inclined end face 32Bs of each I-shaped core 3Ig.

[0154] In the tenth embodiment, two inclined gaps 30s are provided at both ends in the length direction of one of the connecting portions 33B of the core 3I, but two inclined gaps 30s may be provided at diagonal positions of the core 3J as in the present embodiment. According to the above structure, a more uniform magnetic flux density distribution can be obtained than that of the core 3I of the tenth embodiment, and the inductance is improved.

[0155] <Twelfth embodiment>

[0156] Fig.18 The reactor 1K of this embodiment is different from the reactors 1I and 1J of the tenth and eleventh embodiments in the number and positions of the inclined gaps 30s provided only on the iron core 3K, so duplicate descriptions are omitted.

[0157] In the present embodiment, each of the pair of U-shaped cores 3Ub is divided into one I-shaped core 31c and two I-shaped cores 31g. Inclined gaps 30s are formed between the inclined end face 33As and the inclined end face 33As of the I-shaped core 31c constituting the connection portion 33A and the inclined end face 32As of the I-shaped core 31g constituting a portion 32AA of the leg 32A and the inclined end face 32Bs of the I-shaped core 31g constituting a portion 32BA of the leg 32B, and between the inclined end face 33Bs and the inclined end face 33Bs of the I-shaped core 31c constituting the connection portion 33B and the inclined end face 32As of the I-shaped core 31g constituting the other portion 32AB of the leg 32A and the inclined end face 32Bs of the I-shaped core 31g constituting the other portion 32BB of the leg 32B.

[0158] In the iron core 3I of the tenth embodiment and the iron core 3J of the eleventh embodiment, the inclined gaps 30s are provided at two corners of the R-shaped iron core, but the inclined gaps 30s may be provided at all four corners of the iron core 3K as in the present embodiment. By providing the inclined gaps 30s at all corners of the iron core 3K, the decrease in the magnetic flux density generated at the corners of the iron core can be further alleviated, so that a more uniform magnetic flux density distribution can be obtained, and thus the inductance is further improved.

[0159] The above is an explanation of the embodiments of the present invention, but the present invention is not limited to the structure of the embodiments, and various modifications can be made within the scope of its technical concept. For example, a structure obtained by appropriately combining at least a part of the technical structure of one or more embodiments recorded in the specification with a known technical structure is also included in the embodiments of the present invention.

[0160] In the above-described 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 .

[0161] In the seventh to twelfth embodiments ( Figure 13 to Figure 18 ), the plurality of vertical gaps in each magnetic circuit of the core have the same gap length, but some or all of the plurality of vertical gaps may have different gap lengths. However, when a plurality of magnetic circuits are formed on the core, it is desirable that the total gap lengths of the vertical gaps in each magnetic circuit are the same value. For example, in the eighth embodiment ( Fig.14 ) When the coil 2 is mounted on the middle leg portion 31 of the core 3G, even if the gap length of one vertical gap 30pa is increased and the gap length of another vertical gap 30pa is decreased, the gap lengths of the four vertical gaps 30pc are the same. In this case, the total gap lengths of the vertical gaps 30p (30pa, 30pb, 30pc) in the two magnetic paths formed on the core 3G are also equal. In addition, for example, in the ninth embodiment ( Fig.15 ), even if the gap length of the vertical gap 30pb is increased and the gap length of the vertical gap 30pd is decreased, the gap lengths of the two vertical gaps 30pd are the same. In this case, the total gap lengths of the vertical gaps 30p (30pb, 30pd, 30pd) in the two magnetic paths formed on the iron core 3H are also equal.

[0162] In the first to ninth embodiments, a structure is adopted in which one iron core is mounted on the middle leg portion 31. However, a structure in which a pair of iron cores are respectively mounted on a pair of outer leg portions 32 may also be adopted. In addition, a structure in which iron cores are mounted on all of the middle leg portion 31 and a pair of outer leg portions 32 may also be adopted. In addition, a structure in which the iron core includes a plurality of middle leg portions 31 may also be adopted. In this case, a structure in which an iron core is mounted on at least one of the middle leg portions 31 or a structure in which an iron core is mounted only on the outer leg portions 32 may also be adopted.

[0163] In each of the above embodiments, since the outer leg portion 32 and the connecting portion 33 have the same width (that is, the length in the horizontal direction 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 portion 32 and the connecting portion 33. However, the present invention is not limited to the above structure, and an inclined gap 30s inclined at an inclination angle of, for example, 20°, 30°, 40°, 50°, 60°, 70° or other inclination angles with respect to the length direction of the outer leg portion 32 may also be provided. As Figure 2 shown, the inclined gap 30s is formed in a manner of converging the inner angle C A of the corner portion C i of the frame-shaped portion with the outer angle C o of the corner portion C. Therefore, the inclination angle of the inclined gap 30s changes according to the relationship between the thicknesses of the outer leg portion 32 and the connecting portion 33.

[0164] The iron cores 3, 3A to 3E in the above embodiments are examples in which the present invention is applied to a laminated magnetic core. However, the present invention can also be applied to magnetic cores made of other materials (for example, powder compact magnetic cores, ferrite magnetic cores, amorphous metal magnetic cores, metal composite magnetic cores formed of a resin containing magnetic particles, etc.).

[0165] The iron cores 3, 3A to 3E in the above embodiments are U-shaped (H-shaped) iron cores having one middle leg portion 31 and two outer leg portions 32A and 32B. However, they may also have other shapes (for example, an iron core having two or more middle leg portions or an iron core having a cylindrical middle leg portion, etc.).

[0166] The above embodiments apply the present invention to a reactor. However, the present invention is not limited to the above structure. For example, the present invention can be applied to various inductors such as transformers or chokes.

Claims

1. A magnetic core having: Multiple feet; and A pair of connecting parts magnetically connects one end portion and the other end portion of the plurality of legs in the longitudinal direction to each other, respectively. A magnetic gap, i.e., a vertical gap, which is 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, the pair of outer legs magnetically connecting one end portion and the other end portion of the pair of connecting portions in the length direction to each other, respectively. The pair of outer legs and the pair of connecting portions form a frame-shaped portion, A magnetic gap, ie, an inclined gap, is formed at at least one corner of the frame-shaped portion. The magnetic gap is formed by connecting an inner corner and an outer corner.

2. The magnetic core according to claim 1, wherein: One end face of one of the connecting parts is a first inclined end face inclined relative to the length direction of the connecting part, One end surface of one of the outer legs is a second inclined end surface inclined relative to the length direction of the outer leg, The inclined gap is formed in a space sandwiched between the first inclined end surface and the second inclined end surface.

3. The magnetic core according to claim 1, wherein: Two inclined gaps are formed in the frame-shaped portion, The inclined gap is formed adjacent to both end portions of one of the connecting portions.

4. The magnetic core according to claim 1, wherein: Two 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 the other end of the other connecting portion.

5. The magnetic core according to claim 1, wherein: The inclined gaps are formed at four corners of the frame-shaped portion.

6. The magnetic core according to claim 1, wherein: The vertical gap is formed between at least one end portion of the leg portion and one of the connecting portions.

7. The magnetic core according to claim 6, wherein: The vertical gap is formed between at least one other end portion of the leg portion and the other connecting portion.

8. The magnetic core according to claim 1, wherein The vertical gap is formed in a middle portion of at least one length direction of the foot.

9. The magnetic core according to claim 1, wherein: A closed magnetic circuit is formed by the pair of outer legs and the pair of connecting portions. A value of a ratio X / G of a sum of lengths X of the inclined gaps formed in the closed magnetic circuit to a sum of lengths G of the vertical gaps is greater than or equal to 0.

33.

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

11. The magnetic core according to any one of claims 1 to 8, wherein: The plurality of legs include a middle leg disposed between the pair of outer legs.

12. The magnetic core according to claim 11, wherein: A closed magnetic circuit is formed by the middle leg, one of the outer legs and the pair of connecting portions. A value of a ratio X / G of a sum of lengths X of the inclined gaps formed in the closed magnetic circuit to a sum of lengths G of the vertical gaps is greater than or equal to 0.

33.

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

14. The magnetic core according to claim 11, wherein: A first closed magnetic circuit is formed by the middle leg, one of the outer legs and the pair of connecting portions, A second closed magnetic circuit is formed by the middle leg, the other outer leg and the pair of connecting parts. The sum of the lengths X of the inclined gaps formed in the first closed magnetic circuit is equal to the sum of the lengths X of the inclined gaps formed in the second closed magnetic circuit.

15. A coil device comprising: The magnetic core according to any one of claims 1 to 10, and A winding mounted on any one of the plurality of legs.

16. A coil device comprising: The magnetic core according to claim 11, and A winding mounted on any one of the plurality of legs.

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