Choke coil with iron cores, as well as rectifier provided therewith, LC filter provided therewith, and motor drive device provided therewith

Abstract

Choke coil (1), comprising several iron nuclei (11, 12); and Windings (13) wound around any of the plurality of iron cores, wherein a gap (20) is formed between two opposing iron cores, and a gap counter surface (21) of one (11) of the iron cores has a larger surface dimension than a gap counter surface (22) of the other (12) of the iron cores, gaps (20) are formed between iron cores arranged approximately side by side in the circumferential direction, on each iron core, a first gap counter surface (21) is formed, which is opposite an iron core arranged next to one side of the respective iron core, and a second gap counter surface (22) is formed, which is opposite an iron core arranged next to the other side of the respective iron core, in the case of two iron cores arranged side by side, the first gap counter surface (21) of one iron core is opposite the second gap counter surface (22) of the other iron core, and the first gap counter surface (21) has a larger surface dimension than the second gap counter surface (22), wherein the first gap counter surface (21) has a recessed shape of one iron core and the second gap counter surface (22) of the other iron core has a projecting shape, wherein the surroundings of the outer edge of the first gap counter surface (21) of the first iron core and the axial direction form an acute angle to the interior of the first iron core, the vicinity of the outer edge of the second gap counter surface (22) of the second iron core and the axial direction form an obtuse angle to the interior of the second iron core, wherein the first iron core (11) in the vicinity of the gap (20) has a projection portion (40) such that the thickness of the first iron core (11) in the region close to the gap (20) is thicker than the region of the first iron core (11) in the vicinity of this gap (20) and the second iron core (12).

Description

General state of the art

[0001] The present invention relates to a choke coil with iron cores, as well as a rectifier provided therewith, an LC filter provided therewith and a motor drive device provided therewith.

[0002] In an iron-core choke coil, windings are wound around the iron cores, a magnetic flux is generated by a current flow in the windings, and most of the magnetic energy that has become magnetic flux is temporarily stored in gaps formed between the iron cores.

[0003] For example, in motor drive devices that drive motors in machine tools, forging presses, injection molding machines, industrial machinery, or various types of robots, the AC power supplied from an AC power source is temporarily converted into DC power by a rectifier and then converted back into AC power by an inverter. This AC power is used to drive the motors installed on each drive axis. Reactors have a wide range of applications in the industry, including as an AC reactor installed on the AC input side of the rectifier in a motor drive device, a smoothing reactor installed on the DC output side of the rectifier, or a reactor forming an LC filter on the AC output side of the inverter.

[0004] Traditionally, attempts have been made to store large amounts of magnetic energy using a small number of iron cores and windings. Various methods have also been proposed to reduce the eddy current loss caused by the eddy current generated by the stray magnetic flux from near the gaps in the windings.

[0005] For example, as described in Patent Application JP S55 - 53 404 A, there is a reactor in which the gaps formed with respect to the iron cores are inclined at an acute angle with respect to the axial direction and the area dimension of the gaps is made larger than the cross-sectional area of ​​the iron cores in order to store even more magnetic energy.

[0006] For example, as described in Patent Application Laid-Open No. JP 2008 210 998 A, a reactor in which the windings are kept away from the vicinity of the gaps or no windings are arranged near the gaps has also been proposed in order to control the eddy current loss of the windings caused by the stray magnetic flux from the gaps.

[0007] When current flows in the windings wound around the iron cores, magnetic flux flows in the iron cores of the reactor and in the gaps between the iron cores, forming so-called magnetic paths. When a magnetic flux passes through a gap, the magnetic flux tends to enter and exit as perpendicularly as possible with respect to the iron cores on both sides of the gap. Therefore, the gap shape of a conventional reactor has the problem that stray magnetic flux near the gap is easily radiated to the windings. This problem can be explained as follows, taking the reactor described in Japanese Patent Laid-Open No. 55-53404 as an example.

[0008] Fig. 30A is a view for explaining the leakage magnetic flux in the reactor described in Patent Application JP S55-53404A, or an overall sectional view schematically showing the structure of the reactor. Fig. Fig. 30B is a view for explaining the leakage magnetic flux in the reactor described in Patent Application JP S55-53404A, or a partial sectional view schematically showing the magnetic flux generated in the reactor. As shown in Fig. As shown in Figure 30A, the reactor 101 described in Japanese Patent Laid-Open No. S55-53404A has a structure such that a recess-side iron core 111 and a projection-side iron core 112 are formed across a gap 120, and windings 113 are wound around the recess-side iron core 111 and the projection-side iron core 112. The recess-side iron core 111 has a recess-side gap counter surface 121 as a surface facing the gap 120, and the projection-side iron core 112 has a projection-side gap counter surface 122 as a surface facing the gap 120. When a current flows in the windings, a magnetic flux is generated. In the example shown in the drawings, the case of the generation of the magnetic flux is shown in the direction of the dotted arrows. A main magnetic flux flows inside the recess-side iron core 111 and the projection-side iron core 112 of the choke coil 101.The magnetic flux perpendicularly leaked from the protrusion-side gap counter surface 122 of the protrusion-side iron core 112 primarily perpendicularly penetrates the recess-side gap counter surface 121 of the recess-side iron core 111, but a portion perpendicularly penetrates the side surfaces of the recess-side gap counter surface 111 (i.e., surfaces other than the recess-side gap counter surface 121). The magnetic flux perpendicularly penetrating these side surfaces of the recess-side iron core 111 is a leakage magnetic flux. Thus, the reactor 101 described in Japanese Patent Laid-Open No. S55-53404 A has a problem that a large amount of leakage magnetic flux is generated.

[0009] Consequently, in a conventional reactor having a structure that generates a lot of stray magnetic flux, there is a problem that the shape of the windings must be made large and the reactor must be made large in order to store more magnetic energy and reduce eddy current loss. Brief description of the invention

[0010] The invention is based on the object of providing a choke coil that stores more magnetic energy and reduces eddy current loss while suppressing the generation of stray magnetic flux near the gap. Furthermore, the invention is based on the object of providing a rectifier, an LC filter, and a motor drive device comprising such a choke coil.

[0011] According to the invention, the above-mentioned object is achieved with respect to the choke coil by the subject matter of claims 1, 2, and 3, respectively. With respect to the rectifier, the LC filter, and the motor drive device, the above-mentioned object is achieved by the subject matter of claim 6 (rectifier), claim 7 (LC filter), and claim 8 (motor drive control).

[0012] Specifically, the object is achieved by a choke coil comprising: a plurality of iron cores and windings wound around any one of the plurality of iron cores, wherein a gap is formed between two opposing iron cores, and a gap counter surface of one of the iron cores has a larger surface area than a gap counter surface of the other of the iron cores. Gaps are formed between iron cores arranged adjacent to one another approximately in the circumferential direction. On each iron core, a first gap counter surface is formed, which faces an iron core arranged adjacent to one side of the respective iron core, and a second gap counter surface is formed, which faces an iron core arranged adjacent to the other side of the respective iron core.In two iron cores arranged side by side, the first gap counter surface of one iron core lies opposite the second gap counter surface of the other iron core, wherein the first gap counter surface has a larger surface dimension than the second gap counter surface. The first gap counter surface has a recessed shape of one iron core and the second gap counter surface of the other iron core has a projecting shape, wherein the area around the outer edge of the first gap counter surface of the first iron core and the axial direction form an acute angle to the interior of the first iron core. The area around the outer edge of the second gap counter surface of the second iron core and the axial direction form an obtuse angle to the interior of the second iron core.The first iron core has a protrusion portion near the gap such that the thickness of the first iron core in the portion close to the gap is thicker than the portion of the first iron core in the vicinity of this gap and the second iron core.

[0013] According to another aspect, the invention relates to a choke coil comprising a plurality of iron cores and windings wound around any one of the plurality of iron cores, wherein a gap is formed between two opposing iron cores, and a gap counter surface of one of the iron cores has a larger surface dimension than a gap counter surface of the other of the iron cores. The plurality of iron cores comprises a plurality of first iron cores and a plurality of second iron cores, each having a first gap counter surface and a second gap counter surface as surfaces that oppose each other, wherein the first iron cores are arranged adjacent to one another approximately in the circumferential direction, and the second iron cores are arranged adjacent to one another approximately in the circumferential direction such that the second gap counter surface of a respective second iron core is opposite the first gap counter surface of a first iron core adjacent to this second iron core.The windings are wound around the second iron cores. The first gap counter surface or the second gap counter surface has a larger surface area than the other opposite surface. On the first gap counter surface, recessed shapes and protruding shapes are alternately formed in a number one smaller than that of the recessed shapes, and on the second gap counter surface, recessed shapes and protruding shapes are alternately formed in a number one larger than that of the recessed shapes.

[0014] According to another aspect, the invention relates to a reactor comprising a plurality of iron cores and windings wound around any one of the plurality of iron cores, wherein a gap is formed between two opposing iron cores. The plurality of iron cores includes a plurality of second iron cores having two second gap mating surfaces, and a first iron core having first gap mating surfaces in the same number as the total number of second gap mating surfaces of the second iron cores. The second iron cores are arranged adjacent to one another approximately in the circumferential direction such that each of the second gap mating surfaces of a respective second iron core is opposite to one of the first gap mating surfaces of the first iron core. The windings are wound around the second iron cores. One of the first gap mating surfaces and the second gap mating surfaces has a larger surface dimension than the other.On the first gap counter surface, recessed shapes and projecting shapes are alternately formed in a number one less than that of the recessed shapes, and on the second gap counter surface, recessed shapes and projecting shapes are alternately formed in a number one higher than that of the recessed shapes.

[0015] Here, the individual iron cores can be in contact at points other than the gap counter surfaces or can be made in one piece.

[0016] The bottom portion of the recessed shape may have the shape of a curved surface, and the apex portion of the projecting shape may have the shape of a curved surface.

[0017] In a rectifier according to one form of the present invention, one or more of the above reactors is formed as an AC reactor on the AC input side of the rectifier or as a smoothing reactor on the DC output side of the rectifier.

[0018] In an LC filter according to one form of the present invention, one or more of the above choke coils is formed as a choke coil constituting the LC filter.

[0019] In a motor driving device according to one form of the present invention, one or more of the above reactors are configured as at least one of an AC reactor on the AC input side of a rectifier that converts AC power input from an AC power source into DC power, a smoothing reactor on the DC output side of the rectifier, or a reactor constituting an LC filter on the AC output side of an inverter that converts DC power output from the rectifier into AC power for motor driving. Simple explanation of the drawings

[0020] The present invention will be more clearly understood by reference to the accompanying drawings. Fig. 1A is a view showing a reactor according to a first embodiment of the present invention and an overall sectional view schematically showing the structure of the reactor. Fig. 1B is a view showing the reactor according to the first embodiment of the present invention and a partial sectional view schematically showing the magnetic flux generated in the reactor. Fig. 2 is an oblique view when the shape of the leg portions of the choke coil is changed according to the Fig. 1A and Fig. 1B is a cylindrical choke coil. Fig. 3 is an oblique view when the shape of the leg portions of the choke coil is changed according to the Fig. 1A and Fig. 1B is a square choke coil. Fig. 4A is a view for explaining a comparison of the reactor according to the Fig. 1A and Fig. 1B and the reactor described in Patent Application JP S55 - 53 404 A, and a partial sectional view showing the inductance used in the reactor according to the invention shown in Fig. 1A and Fig. 1B shows a schematic representation of the magnetic flux resulting from the first embodiment of the present invention. Fig. 4B is a view for explaining a comparison of the reactor according to the Fig. 1A and Fig. 1B and the reactor described in Patent Laid-Open No. JP S55-53404A, and a partial sectional view schematically showing the magnetic flux generated in the reactor described in Patent Laid-Open No. JP S55-53404A. Fig. 5A is a view showing a reactor according to a second embodiment of the present invention and an overall sectional view schematically showing the structure of the reactor. Fig. 5B is a view showing the reactor according to the second embodiment of the present invention and a partial sectional view schematically showing the magnetic flux generated in the reactor. Fig. 6A is a view showing the result of simulation of the magnetic flux density in the reactor according to the first embodiment of the present invention, and a view for explaining the change in the magnetic flux density in association with a change in the gap shape. Fig. 6B is a view showing the result of simulation of the magnetic flux density in the reactor according to the first embodiment of the present invention, and a view for explaining the change in the magnetic flux density in association with a change in the gap shape under the inductance constant. Fig. 6C is a view showing the result of simulation of the magnetic flux density in the reactor according to the first embodiment of the present invention, and a view for explaining the change in the magnetic flux density near the gap in association with a change in the gap shape under the inductance constant. Fig. 7A is a view showing the result of simulation of the magnetic flux density in the reactor according to the second embodiment of the present invention, and a view for explaining the change in the magnetic flux density in association with a change in the gap shape. Fig. 7B is a view showing the result of simulation of the magnetic flux density in the reactor according to the second embodiment of the present invention, and a view for explaining the change in the magnetic flux density in association with a change in the gap shape under the inductance constant. Fig. 7C is a view showing the result of simulation of the magnetic flux density in the reactor according to the second embodiment of the present invention, and a view for explaining the change in the magnetic flux density near the gap in association with a change in the gap shape under the inductance constant. Fig. 8A is a view showing the result of simulation of the magnetic flux density in the reactor according to the method disclosed in Patent Application JP S55 - 53 404 A described invention, and a view for explaining the change in magnetic flux density in connection with a change in the gap shape. Fig. Fig. 8B is a view showing the result of simulation of the magnetic flux density in the reactor according to the method disclosed in Patent Application JP S55 - 53 404 A described invention, and a view for explaining the change in magnetic flux density in connection with a change in gap shape under the inductance constant. Fig. 8C is a view showing the result of simulation of the magnetic flux density in the reactor according to the method disclosed in Patent Application JP S55 - 53 404 described invention, and a view for explaining the change in magnetic flux density near the gap in connection with a change in the gap shape under the inductance constant. Fig. Figure 9 is a view showing the measuring point of the magnetic flux density in the reactor in the simulation analysis. Fig. 10 is a partial sectional view showing a reactor according to a third embodiment of the present invention. Fig. 11 is a partial sectional view showing a reactor according to a fourth embodiment of the present invention. Fig. 12 is a partial sectional view showing a reactor according to a fifth embodiment of the present invention. Fig. 13 is a partial sectional view showing a reactor according to a sixth embodiment not according to the present invention. Fig. 14 is a partial sectional view showing a reactor according to a seventh embodiment of the present invention. Fig. 15 is a partial sectional view showing a reactor according to an eighth embodiment of the present invention. Fig. 16A and Fig. 16B are overall sectional views showing a reactor according to a ninth embodiment of the present invention. Fig. 17A is a view showing a reactor according to a tenth embodiment not according to the present invention. Fig. 17B is a view showing the reactor according to the tenth embodiment not according to the invention, and an enlarged sectional view of the position within the dot-dashed line in Fig. 17A. Fig. 18 is an overall sectional view showing a reactor according to an eleventh embodiment not according to the present invention. Fig. 19A is an overall sectional view showing a reactor according to a twelfth embodiment not according to the present invention, and showing an example in which windings are wound around all the iron cores. Fig. 19B is an overall sectional view showing the reactor according to the twelfth embodiment not according to the invention, and shows an example in which windings are wound around a part of the iron cores. Fig. 20A is an overall sectional view showing a reactor according to a thirteenth embodiment not according to the present invention, and showing an example in which windings are wound around all the iron cores. Fig. 20B is an overall sectional view showing the reactor according to the thirteenth embodiment not according to the present invention, and shows an example in which windings are wound around a part of the iron cores. Fig. 21A is an overall sectional view showing a reactor according to a fourteenth embodiment not according to the present invention. Fig. Fig. 21B is a view showing the reactor according to the fourteenth embodiment not according to the invention, and an enlarged sectional view of the position within the dot-dashed line in Fig. 21A. Fig. 22A is an overall sectional view showing a reactor according to a fifteenth embodiment not according to the present invention. Fig. Fig. 22B is a view showing the reactor according to the fifteenth embodiment not according to the invention, and an enlarged sectional view of the position within the dot-dashed line in Fig. 22A. Fig. 23 is an overall sectional view showing a modification of the reactor according to the tenth embodiment not according to the present invention. Fig. 24 is an overall sectional view showing a modification of the reactor according to the eleventh embodiment not according to the present invention. Fig. 25A is an overall sectional view showing a modification of the reactor according to the twelfth embodiment not according to the present invention, and showing an example in which windings are wound around all the iron cores. Fig. 25B is an overall sectional view showing the modification of the reactor according to the twelfth embodiment not according to the present invention, and showing an example in which windings are wound around a part of the iron cores. Fig. 26A is an overall sectional view showing a modification of the reactor according to the thirteenth embodiment not according to the present invention, and showing an example in which windings are wound around all the iron cores. Fig. 26B is an overall sectional view showing the modification of the reactor according to the thirteenth embodiment not according to the present invention, and shows an example in which windings are wound around a part of the iron cores. Fig. 27 is an overall sectional view showing a modification of the reactor according to the fourteenth embodiment not according to the present invention. Fig. 28 is an overall sectional view showing a modification of the reactor according to the fifteenth embodiment not according to the present invention. Fig. 29 is a view showing a motor driving device provided with a reactor according to one form of the present invention. Fig. 30A is a view for explaining the leakage magnetic flux in the reactor described in Patent Application JP S55-53404A, or an overall sectional view schematically showing the structure of the reactor. Fig. 30B is a view for explaining the leakage magnetic flux in the reactor described in Patent Application JP S55-53404A, or a partial sectional view schematically showing the magnetic flux generated in the reactor. Detailed explanation

[0021] Next, embodiments of the present invention will be explained with reference to the drawings. For ease of understanding, the scale in the following drawings has been arbitrarily changed. The embodiment shown in the drawings is an example of the embodiment of the present invention, but is not limited to the present embodiment.

[0022] In this specification, the "axial direction" indicates the direction of the main magnetic flux flowing in the iron cores of the reactor. When "the inner angle among the angles formed by the vicinity of the outer edge of a surface and the axial direction" is specified in this specification with respect to the first gap counter surface and the second gap counter surface, this means the "smaller angle" or "lower angle" among the two angles formed by the surface in the vicinity of the outer edge of the surface in question and the axial direction on the axis center side, rather than the "larger angle" or "upper angle." In this specification, the smaller angle may also mean the so-called "inner angle."

[0023] The reactor according to one form of the present invention includes a plurality of iron cores and windings wound around any one of the plurality of iron cores, wherein a gap is formed between two opposing iron cores, and the gap counter surface of one iron core has a larger area than the gap counter surface of the other iron core. The specific structure will be explained below through first to fifteenth embodiments.

[0024] Fig. 1A is a view showing a reactor according to a first embodiment of the present invention and an overall sectional view schematically showing the structure of the reactor. Fig. 1B is a view showing the reactor according to the first embodiment of the present invention and a partial sectional view schematically showing the magnetic flux generated in the reactor. Fig. 2 is an oblique view when the shape of the leg portions of the choke coil is changed according to the Fig. 1A and Fig. 1B is a cylindrical choke coil, and Fig. 3 is an oblique view when the shape of the leg portions of the choke coil is changed according to the Fig. 1A and Fig. 1B is a square choke coil.

[0025] The choke coil 1 according to the first embodiment of the present invention comprises a first iron core 11, a second iron core 12 and windings 13. A gap 20 is formed between the first iron core 11 and the second iron core 12, which are opposite to each other.

[0026] The first iron core 11 has a first gap counter surface 21 as a surface opposite the gap 20 formed with the second iron core 12. The vicinity of the outer edge of the first gap counter surface 21 of the first iron core 11 and the axial direction form an acute angle with the interior of the first iron core 11. That is, since the inner angle forms an acute angle among the angles formed by the vicinity of the outer edge of the first gap counter surface 21 and the axial direction, the first gap counter surface 21 has an inclined structure in which the surface surrounding the outer edge forms an acute angle with respect to the axial direction.

[0027] The second iron core 12 has a second gap counter surface 22 as a surface opposite to the first gap counter surface 21 of the first iron core 11 across the gap 20. The vicinity of the outer edge of the second gap counter surface 22 of the second iron core 12 and the axial direction form an obtuse angle with the interior of the second iron core 12. That is, since the inner angle forms an obtuse angle among the angles formed by the vicinity of the outer edge of the second gap counter surface 22 and the axial direction, the second gap counter surface 22 has an inclined structure in which the surface of the vicinity of the outer edge forms an obtuse angle with respect to the axial direction.

[0028] In the example shown, the first gap counter surface 21 of the first iron core 11 has a recessed shape and the second gap counter surface 22 of the second iron core 12 has a projecting shape.

[0029] The first iron core 11 and the second iron core 12 can also be designed such that they are in contact at locations other than the first gap counter surface 21 and the second gap counter surface 22 or are designed as one piece.

[0030] The windings 13 are wound around either one or both of the first iron core 11 and the second iron core 12, but in the illustrated example, the windings 13 are wound around the first iron core 11 and the second iron core 12. When wound around both, the windings can be wound as in the later-described Fig. 16b may also be split near the gap.

[0031] In the reactor 1 according to the first embodiment of the present invention, the first gap counter surface 21 of the first iron core 11 is configured to have a larger surface area than the second gap counter surface 22 of the second iron core 12. In other words, the first iron core 11 and the second iron core 12 have a structure such that the length of the outer peripheral edge consisting of the intersection line of the first gap counter surface 21 of the first iron core 11 and the surface 31 adjacent to this first gap counter surface 21 becomes longer than the length of that outer peripheral edge consisting of the intersection line of the second gap counter surface 22 of the second iron core 12 and the surface 32 adjacent to this second gap counter surface 22. Consequently, as in Fig. 1A and Fig. 1B, the first iron core 11 has a structure having a protrusion portion 40 in the vicinity of the gap 20, and the thickness of the first iron core 11 in the region close to the gap becomes thicker than the region of the first iron core 11 in the vicinity of this gap and the second iron core 12. Fig. 1A and Fig. 1B show an example of the above-described structure of the first iron core 11 and the second iron core 12, and later, modifications of the above structure example for the first iron core 11 and the second iron core will be described.

[0032] In Fig. 1B, the magnetic flux that occurs when a current flows in the windings 13 is shown by dashed arrows. When a current flows in the windings 13 (in Fig. 1B not shown), a magnetic flux flows inside the first iron core 11 and the second iron core 12 of the choke coil 1, as well as in the gap 20 between these iron cores, forming a so-called magnetic path. Since the magnetic permeability of the first iron core 11 and the second iron core 12 is higher than that of the gap 20, which is a non-magnetic body, the magnetic flux tends to diverge when the magnetic flux passes through the gap 20, and therefore the magnetic flux density of the gap 20 becomes lower than the magnetic flux density in the iron cores. In addition, the magnetic flux also exhibits the characteristic of attempting to enter and exit as perpendicularly as possible with respect to the first iron core 11 and the second iron core 12.Therefore, when a main magnetic flux flows in the first iron core 11 and the second iron core 12 of the reactor 1, the main magnetic flux directed from the second iron core 12 to the first iron core 11 requires a wider area than when flowing in the second magnetic core 12. Therefore, part of the main magnetic flux exits not only from the second gap counter surface 22 but also from the side surface 32 of the second iron core 12, and enters perpendicularly to the surface 31 adjacent to the first gap counter surface 21 of the first iron core 11, the surface adjacent to the surface 31 of the protrusion portion 40, and the side surface of the first iron core 11. This will be explained with reference to FIG. Fig. 4A and Fig. 4B explains this in more detail.

[0033] Fig. 4A is a view explaining a comparison of the Fig. 1A and Fig. 1B and the choke coil described in Patent Application JP S55 - 53 404 A, and a partial sectional view showing the choke coil shown in Fig. 1A and Fig. 1B shows a schematic representation of the magnetic flux generated by the choke coil. Fig. 4B is a view explaining a comparison of the Fig. 1A and Fig. 1B and the choke coil described in Patent Application JP S55-53404 A, and a partial sectional view schematically showing the magnetic flux generated in the choke coil described in Patent Application JP S55-53404 A. In Fig. 4A and Fig. 4B, the windings 13 are not shown.

[0034] When comparing the Fig. 1A and Fig. 1B according to the first embodiment of the present invention and the reactor described in Patent Application JP S55-53404A, the magnetic flux density in the iron cores (the first iron core 11, the second iron core 12, the recess-side iron core 111, the projection-side iron core 112) is set as B1, the cross-sectional area in the iron cores (the first iron core 11, the second iron core 12, the recess-side iron core 111, the projection-side iron core 112) is set as S, the gap length is set as Ld, and it is assumed that these parameters are the same as in Fig. 1A and Fig. 1B and the reactor described in Japanese Patent Application Laid-Open No. 55-53404 A. Furthermore, the magnetic flux density of the gap 20 between the first iron core 11 and the second iron core 12 is set as B2, and the magnetic flux density of the gap 120 between the recess-side iron core 111 and the projection-side iron core 112 is set as B3.

[0035] The effective surface dimension of the first gap counter surface 21 and the second gap counter surface 22 of the choke coil 1 according to the Fig. 1A and Fig. 1B, the effective area of ​​the gap counter surfaces is set to [2P(1-α)]. In the reactor 101 described in Japanese Patent Laid-Open No. S55-53404A, the effective area of ​​the gap counter surfaces is [2P(1-α)]. The magnetic flux escaping from the vicinity of the outer edge of the gap counter surface of the projection-side iron core 112 does not enter the gap counter surface of the recess-side iron core 111, and the area of ​​the gap counter surface of the projection-side iron core 112 from which this magnetic flux, which does not enter the gap counter surface of the recess-side iron core 111, escaping is expressed as 2Pα.

[0036] Since the choke coil 1 is Fig. 1A and Fig. 1B, the magnetic flux penetrating the sectional area S of the first iron core 11 or the second iron core 12, the sum of the magnetic flux penetrating the effective area dimension 2P of the first gap counter surface 11 and the second gap counter surface 21 and the leakage magnetic flux is equal to the leakage magnetic flux, if the product of the leakage magnetic flux and the area dimension where the leakage magnetic flux is generated is set as X, the relationship of Equation 1 is established. B1×S=B2×2P+X

[0037] Since the magnetic flux density of the gap is determined by the magnetic flux density B1 in the iron cores and the gap length Ld, the magnetic flux density B2 and B3 of the gap can be expressed as by equation 2. B2=B3

[0038] Therefore, the voltage in the gap 20 of the choke coil 1 is determined according to the Fig. 1A and Fig. 1B shown first embodiment of the present invention stored magnetic energy W1 when the magnetic permeability is defined as µ 0 is set as expressed by equation 3. W1=12×μ0×B22×2P×Ld

[0039] Since, in the reactor 101 described in Patent Application Laid-Open No. JP S55-53404A, the magnetic flux penetrating the surface dimension S of the recess-side iron core 111 or the projection-side iron core 112 is equal to the sum of the magnetic flux penetrating the effective surface dimension of the gap opposing surfaces [2P(1-α)] and the leakage magnetic flux, if the product of the leakage magnetic flux and the surface dimension where the leakage magnetic flux is generated is set as Y, the relationship of Equation 4 is established. B1×S=B3×2P(1−α)+Y

[0040] Therefore, the magnetic energy W2 stored in the gap 120 of the choke coil 101 described in Patent Application JP S55 - 53 404 A when the magnetic permeability is determined as µ 0 is set as expressed by equation 5. W2=12×μ0×B32×2P(1−α)×Ld =12×μ0×B22×2P×Ld−(α2×μ0×B22×2P×Ld)

[0041] Regarding the magnetic flux density of the gap, the relationship of [B2 = B3] exists. Therefore, comparing Equation 3 and Equation 5, the magnetic energy stored in the gap at the choke coil 1 is calculated according to the equation given in Fig. 1A and Fig. 1B is larger than that of the choke coil 101 described in Patent Application JP S55-53404 A.

[0042] The magnetoresistance is expressed by “gap length ÷ magnetic permeability ÷ area dimension”, and the effective area dimension of the gap of the choke coil 1 according to the formula in Fig. 1A and Fig. 1B is larger than the effective area of ​​the gap of the choke coil 101 described in Patent Application JP S55-53404 A [P (1-α) < P]. Consequently, the magnetoresistance in the choke coil 1 is determined according to the formula shown in Fig. 1A and Fig. 1B, the gap magnetoresistance of the first embodiment of the present invention is small compared to the choke coil 101 described in Japanese Patent Application Laid-Open No. 55-53404. That is, in the choke coil 1 according to the first embodiment of the present invention, the gap magnetoresistance is small, and under the same current conditions, the magnetic flux and magnetic flux density can be made large, and the inductance can also be made large. Consequently, a small-sized choke coil 1 can be realized.

[0043] As described above, in the reactor 1 according to the first embodiment of the present invention, by making the thickness of the first iron core 11 in the region close to the gap thicker than the thickness of the region of the first iron core 11 in the vicinity of this gap and the second iron core 12, a structure in which the first gap counter surface 21 has a larger area than the second gap counter surface 22 (that is, a structure in which the length of the outer peripheral edge consisting of the intersection line of the first gap counter surface 21 of the iron core 11 and the surface 31 adjacent to this first gap counter surface 21 becomes longer than the length of that outer peripheral edge consisting of the intersection line of the second gap counter surface 22 of the second iron core 12 and the surface 32 adjacent to this second gap counter surface 22) is obtained.

[0044] Next, as a second embodiment of the present invention, an example in which the area dimension of the first gap counter surface 21 of the first embodiment of the present invention is further larger will be explained. Fig. 5A is a view showing the reactor according to the second embodiment of the present invention and an overall sectional view schematically showing the structure of the reactor. Fig. 5B is a view showing the reactor according to the second embodiment of the present invention and a partial sectional view schematically showing the magnetic flux generated in the reactor. As shown in Fig. 5A and Fig. 5B is shown in the Fig. 5A and Fig. 5B, the projection portion 40 in the second embodiment of the present invention shown in Fig. 1A and Fig. 1B shown first embodiment of the present invention is further extended and a projection area 41 is formed. By this embodiment, as in Fig. 5B, the magnetic flux N emerging from the surface 32 near the gap enters the first gap counter surface 21 of the first iron core 11 perpendicularly under the magnetic flux emerging from the surface 32 adjacent to the second gap counter surface 22 of the second iron core 12 (i.e., the side surface of the second iron core 12). Furthermore, due to the larger size of the projection portion 41, the magnetic flux M emerging from the surface 32 farther from the vicinity of the gap also enters the surface 31 adjacent to the first gap counter surface 21 of the first iron core 11 perpendicularly.Consequently, since a magnetic flux that became a stray magnetic flux in the first embodiment also enters the surface 31 adjacent to the first gap counter surface 21 of the first iron core 11 perpendicularly and passes through the first iron core 11, according to the second embodiment of the present invention, the magnetic flux density in the first iron core 11 becomes higher than in the first embodiment of the present invention. The larger the protrusion portion 41 is (that is, the larger, up to about 1.5 times, the area dimension of the first gap counter surface 21 is than the area dimension of the second gap counter surface 22 is), the higher the magnetic flux density in the first iron core 11 becomes. In the second embodiment, a configuration is also possible in which the first iron core 11 and the second iron core 12 are in contact at locations other than the first gap counter surface 21 and the second gap counter surface 22, or are formed integrally.

[0045] As explained above, since the shape of the gap counter surfaces (including the area dimension) differs between the reactor according to the first embodiment of the present invention, the reactor according to the second embodiment of the present invention, and the reactor of the invention described in Patent Application JP S55-53404A, the shape of the gap between the iron cores also differs. Now, using Fig. 6A, Fig. 6B, Fig. 6C, Fig. 7A, Fig. 7B, Fig. 7C, Fig. 8A, Fig. 8B and Fig. 8C explains simulation results regarding a change in the gap of the reactor in the reactors according to the first and second embodiments of the present invention and the reactor of the invention described in Patent Application Laid-Open No. JP S55-53404A. Fig. Figure 9 is a view showing the measurement point of the magnetic flux density in the reactor during simulation analysis. Fig. 9 is the Fig. 30A according to the invention described in Japanese Patent Application Laid-Open No. 55-53404A was used as an example, but the same position was used as the magnetic flux density measurement point for the reactors according to the first and second embodiments. Point C indicates the magnetic flux density measurement point in the iron core, and point D indicates the magnetic flux density measurement point in the winding.

[0046] Fig. 6A, Fig. 6B and Fig. 6C are views showing the simulation results for the magnetic flux density in the reactor according to the first embodiment of the present invention, wherein Fig. 6A is a view explaining the change in magnetic flux density associated with a change in gap shape, Fig. 6B is a view explaining the change in magnetic flux density associated with a change in gap shape under the inductance constant; and Fig. 6C is a view explaining the change in magnetic flux density near the gap in conjunction with a change in the gap shape under the inductance constant. In Fig. 6C is the magnetic flux density of the leakage magnetic flux in the winding of the middle leg of the Fig. 6B shown in the vicinity of the gap by isolines. Fig. 7A, Fig. 7B and Fig. 7C are views showing the simulation results for the magnetic flux density in the reactor according to the second embodiment of the present invention, wherein Fig. 7A is a view explaining the change in magnetic flux density associated with a change in gap shape, Fig. 7B is a view explaining the change in magnetic flux density associated with a change in gap shape under the inductance constant; and Fig. 7C is a view explaining the change in magnetic flux density near the gap in conjunction with a change in the gap shape under the inductance constant. In Fig. 7C is the magnetic flux density of the leakage magnetic flux in the winding of the middle leg of the Fig. 7B shown in the vicinity of the gap by isolines. Fig. 8A, Fig. 8B and Fig. 8C are views showing the simulation results for the magnetic flux density in the reactor according to the invention described in Patent Application JP S55 - 53404 A, wherein Fig. 8A is a view explaining the change in magnetic flux density associated with a change in gap shape, Fig. 8B is a view explaining the change in magnetic flux density associated with a change in gap shape under the inductance constant; and Fig. 8C is a view explaining the change in magnetic flux density near the gap in conjunction with a change in the gap shape under the inductance constant. In Fig. 8C is the magnetic flux density of the leakage magnetic flux in the winding of the middle leg of the Fig. 8B shown in the vicinity of the gap by isolines. Table 1 shows the change of the magnetic flux density in the iron core in connection with a change of the gap shape in Figure 6A, Figure 7A and Figure 8A as numerical values. Induktivität (mH) Magnetflussdichte (T) in dem Eisenkern Fig. 8A State of the art 0,1138 1,4191 Fig. 6A first embodiment 0,1222 1,4829 Fig. 7A second embodiment 0,1245 1,5002

[0047] As already explained, the effective area dimension of the gap between the iron cores in the order of the reactor is determined according to the invention described in Patent Laid-Open No. JP S55 - 53 404 A ( Fig. 8A), the choke coil according to the first embodiment of the present invention ( Fig. 6A) and the choke coil according to the second embodiment of the present invention ( Fig. 7A), but it can be seen from these figures and Table 1 that the magnetic flux density in the iron core increases as the effective surface area between the iron cores increases. This is because the larger the projection area 41 is (that is, the larger the surface area of ​​the first gap counter surface 21 is than the surface area of ​​the second gap counter surface 22), the greater the opportunity for the magnetic flux M, which exits from the surface 32 further from the vicinity of the gap of one iron core (the second iron core 12), to perpendicularly enter the surface adjacent to the gap counter surface of the other iron core (the first iron core 11). In addition, the inductance in the order of the choke coil according to the invention described in Patent Application Laid-Open No. JP S55-53404 A ( Fig. 8A), the choke coil according to the first embodiment of the present invention ( Fig. 6A) and the choke coil according to the second embodiment of the present invention ( Fig. 7A). This is because α in Equation 5 becomes smaller and consequently the inductance becomes larger the larger the protrusion area 41 is (that is, the larger the area dimension of the first gap counter surface 21 is than the area dimension of the second gap counter surface 22). Table 2 shows the change of magnetic flux density in the iron core and the largest magnetic flux density in the winding associated with a change of the shape of the gap under the inductance constant in Figure 6B and Figure 6C, Figure 7B and Figure 7C, and Figure 8B and Figure 8C. Magnetflussdichte (T) in dem Eisenkern größte Magnetflussdichte (T) in der Wicklung Fig. 8B and Fig. 8C State of the art 1,1325 0,109 Fig. 6B and Fig. 6C first embodiment 1,1336 0,064 Fig. 7B and Fig. 7C second embodiment 1,1345 0,059

[0048] In the simulations for Fig. 6B and Fig. 6C, Fig. 7B and Fig. 7C, and Fig. 8B and Fig. 8C, the number of turns of the winding and the current value were adjusted so that the magnetic flux density in the iron core for each choke coil became approximately constant (the inductance becomes approximately constant). Furthermore, the dimensions were adjusted so that the distance from the projection portion 40 of the iron core 11 or the edge surface of the iron core 111 to the vicinity of the winding became the same. As already explained, the effective area dimension of the gap between the iron cores in the order of the choke coil is adjusted according to the invention described in Patent Application Laid-Open No. JP S55-53404 A ( Fig. 8B and Fig. 8C), the choke coil according to the first embodiment of the present invention ( Fig. 6B and Fig. 6C) and the choke coil according to the second embodiment of the present invention ( Fig. 7B and Fig. 7C) is larger, but it can be seen from these figures and Table 2 that the maximum magnetic flux density in the winding decreases as the effective area between the iron cores increases. As can also be seen by comparing Fig. 6C, Fig. 7C and Fig. 8C, the region with a low magnetic flux density in the winding in the choke coil according to the first embodiment of the present invention ( Fig. 6C) and the choke coil according to the second embodiment of the present invention ( Fig. 7C) is more extensive than in the choke coil according to the invention described in patent application JP S55 - 53 404 A ( Fig. 8C). This is because the larger the protrusion portion 41 is (that is, the larger the area dimension of the first gap counter surface 21 is than the area dimension of the second gap counter surface 22), the more the opportunity for the magnetic flux M, which exits from the vicinity of the gap of one iron core (the second iron core 12) to perpendicularly enter the area adjacent to the gap counter surface of the other iron core (the first iron core 11), increases, and the more the leakage magnetic flux to the winding decreases.

[0049] With reference to Fig. 10 to Fig. 15, third to eighth embodiments are subsequently explained as further modifications of the shapes of the first gap counter surface and the second gap counter surface of the above-described first and second embodiments. In Fig. 10 to Fig. 15, a representation of the winding was omitted.

[0050] First, the third embodiment of the present invention is configured such that the bottom portion of the recessed shape formed by inclined surfaces (i.e., the recessed portion) and the apex portion of the projecting shape (i.e., the projecting portion) in the first gap counter surface and the second gap counter surface have the shape of a curved surface.

[0051] Fig. Fig. 10 is a partial sectional view showing a reactor according to the third embodiment of the present invention. Here, an explanation will be given by way of example of the first gap counter surface 21 and the second gap counter surface 22 in the reactor described with reference to Fig. Fig. 1A and Fig. 1B, but application to the gap counter surfaces of other previously or later described embodiments is also possible. As shown in Fig. 10, the bottom portion of the recessed shape of the first gap counter surface 21 of the first iron core 11 has a curved surface 51 and the apex portion of the projected shape of the second gap counter surface 22 of the second iron core 12 has a curved surface 52.

[0052] The fourth to sixth embodiments of the present invention are embodiments in which the effective area dimension of the gap counter surface is increased by making the thickness of one iron core itself thicker than that of the other iron core itself.

[0053] Fig. 11 is a partial sectional view of a reactor according to the fourth embodiment of the present invention. Fig. 12 is a partial sectional view of a reactor according to the fifth embodiment of the present invention. Fig. 13 is a partial sectional view of a choke coil according to the sixth embodiment, not according to the invention. Also in the fourth to sixth embodiments, the first gap counter surface 21 is designed to have a larger surface area than the second gap counter surface 22 by making the thickness of the first iron core 11 itself thicker than that of the second iron core 12 itself. The choke coils 1 according to the Fig. 12 and the fifth embodiment shown in Fig. 13 are configured such that the third embodiment is also applied, and the bottom portion of the recessed shape of the first gap counter surface 21 of the first iron core 11 has the curved surface 51, and the apex portion of the projected shape of the second gap counter surface 22 of the second iron core 12 has the curved surface 52.

[0054] The seventh and eighth embodiments of the present invention are further modifications of the gap counter surfaces.

[0055] Fig. 14 is a partial sectional view showing a reactor according to the seventh embodiment of the present invention. Fig. In the seventh embodiment of the present invention shown in Fig. 14, the length of the outer peripheral edge consisting of the intersection line of the first gap counter surface 21 of the first iron core 11 and the surface 31 adjacent to this first gap counter surface 21 is designed to be longer than the length of that outer peripheral edge consisting of the intersection line of the second gap counter surface 22 of the second iron core 12 and the surface 32 adjacent to this second gap counter surface 22, and moreover, the first gap counter surface 21 and the second gap counter surface 22 have a curved shape.

[0056] Fig. 15 is a partial sectional view showing a reactor according to the eighth embodiment of the present invention. Fig. In the eighth embodiment of the present invention shown in Figure 15, the first gap counter surface 21 is configured to have a larger area than the second gap counter surface 22, and furthermore, protruding portions and depressed portions are alternately formed on the first gap counter surface 21 and the second gap counter surface 22. More specifically, depressed shapes and protruding shapes are alternately formed on the first gap counter surface 21 in a number one smaller than that of the depressed shapes, and depressed shapes and protruding shapes are alternately formed on the second gap counter surface 22 in a number one larger than that of the depressed shapes, to ensure that the first gap counter surface 21 has a larger area than the second gap counter surface 22. In the example shown in Fig. 15, two recessed shapes and one protruding shape are formed on the first gap counter surface 21, while one recessed shape and two protruding shapes are formed on the first gap counter surface. The choke coil 1 according to the embodiment shown in Fig. The eighth embodiment shown in Fig. 15 is configured such that the third embodiment is also applied, and the bottom portion of the recessed shapes of the first gap counter surface 21 of the first iron core 11 has the curved surface 51, and the apex portion of the projecting shapes of the second gap counter surface 22 of the second iron core 12 has the curved surface 52.

[0057] Also in the third to eighth embodiments described above, a configuration is possible in which the first iron core 11 and the second iron core 12 are in contact at locations other than the first gap counter surface 21 and the second gap counter surface 22 or are formed integrally.

[0058] An explanation has been given for the case where the reactors according to the first to eighth embodiments described above are three-phase reactors, but the reactor according to one form of the present invention may also be implemented as a single-phase reactor. Fig. 16A and Fig. 16B are overall sectional views showing a reactor according to a ninth embodiment of the present invention. The structure of the reactor 1, which is a single-phase reactor, according to the ninth embodiment of the present invention is based, for example, on the structure shown in Fig. 16A shown on the with reference to Fig. 1A and Fig. 1B explained three-phase reactor according to the first embodiment. If the single-phase reactor is formed such that the vicinity of the outer edge of the first gap counter surface 21 of the first iron core 11 and the axial direction form an acute angle to the interior of the first iron core 11, and the vicinity of the outer edge of the second gap counter surface 22 of the second iron core 12 and the axial direction form an obtuse angle to the interior of the second iron core 12, and the first gap counter surface 21 of the first iron core 11 has a larger surface dimension than the second gap counter surface 22 of the second iron core 12, it can be further formed with a structure different from that shown in Fig. 16A and, for example, as shown in Fig. 16B. Also in the ninth embodiment, the first iron core 11 and the second iron core 12 may be in contact at locations other than the first gap counter surface 21 and the second gap counter surface 22, or may be formed integrally.

[0059] Subsequently, modifications in which the choke coil is designed as a square columnar choke coil according to the first form will be described with reference to Fig. 17A to Fig. 28 are explained as tenth to fifteenth embodiments not according to the invention.

[0060] Fig. 17A is an overall sectional view showing a reactor according to the tenth embodiment not according to the present invention. Fig. 17B is a view showing the reactor according to the tenth embodiment not according to the invention, and an enlarged sectional view of the position within the dot-dashed line in Fig. 17A. The reactor 1 according to the tenth embodiment is designed as a three-phase reactor with the shape of a square column. In the reactor 1 according to the tenth embodiment, as shown in Fig. 17A and Fig. As shown in Fig. 17B, a gap 20 is formed between the iron cores 14-1 and 14-2, the iron cores 14-2 and 14-3, and the iron cores 14-3 and 14-1, which are arranged approximately adjacent to one another in the circumferential direction. On each of the iron cores 14-1, 14-2, and 14-3, a first gap counter surface 21, which is opposite to the iron core arranged adjacent to one side of the respective iron core, and a second gap counter surface 22, which is opposite to the iron core arranged adjacent to the other side of the respective iron core, are formed. More specifically, a first gap counter surface 21, which is opposite to the iron core 14-2 arranged next to one side of the respective iron core 14-1, and a second gap counter surface 22, which is opposite to the iron core 14-3 arranged next to the other side of the respective iron core 14-1, are formed on the iron core 14-1.On the iron core 14-2, a first gap counter surface 21 is formed, which faces the iron core 14-3 arranged adjacent to one side of the respective iron core 14-2, and a second gap counter surface 22 is formed, which faces the iron core 14-1 arranged adjacent to the other side of the respective iron core 14-2. On the iron core 14-3, a first gap counter surface 21 is formed, which faces the iron core 14-1 arranged adjacent to one side of the respective iron core 14-3, and a second gap counter surface 22 is formed, which faces the iron core 14-2 arranged adjacent to the other side of the respective iron core 14-3. Thus, in the tenth embodiment, when two iron cores are arranged adjacent to one another, the first gap counter surface 21 of one iron core faces the second gap counter surface 22 of the other iron core, and the first gap counter surface 21 has a larger surface dimension than the second gap counter surface 22.The number of iron cores is determined by the number of poles of the reactor 1. For example, when the number of poles is two, the number of iron cores is two, and when the number of poles is six, the number of iron cores is six. In the example shown in the drawings, the number of poles of the reactor 1 was set to three, but the number of poles itself is not limited to the present embodiment, and other pole numbers are also possible. In addition, the shape of the coil shown in . Fig. 17A and Fig. 17B are exemplary, and any shape is possible as long as it is a shape in which the first gap counter surface 21 and the second gap counter surface 22 satisfy the relationship described above. Exemplary other embodiments for the number of poles and the shape of the iron cores will be described later with reference to Fig. 18 to 20B. When a plurality of groups of first gap counter surfaces and second gap counter surfaces are provided, the effect of increasing the inductance and decreasing the leakage magnetic flux is produced when the gap counter surfaces between iron cores of at least one of the groups have a shape satisfying the relationship described above, but it will be easy to imagine that this effect is maximized when all groups of gap counter surfaces satisfy the relationship described above.

[0061] Fig. Fig. 18 is a cross-sectional view showing a reactor according to the eleventh embodiment of the present invention. The reactor 1 according to the eleventh embodiment of the present invention is designed as a three-phase reactor having a square column shape. When the number of poles of the iron cores is high compared to the number of phases, windings 13 are wound around as many iron cores of the plurality of iron cores as there are phases (or a multiple thereof). Fig. In the example shown in Fig. 18, iron cores 61-1, 61-2, 61-3, 61-4, 61-5, and 61-6 of six poles are arranged approximately circumferentially adjacent to each other, but since the reactor 1 is designed as a three-phase reactor, windings 13 are wound around three of the six iron cores (reference numerals 61-2, 61-4, and 61-6 in the example shown). In addition, in the example shown in Fig. In the example shown in Figure 18, the first gap counter surfaces 21 and the second gap counter surfaces 22 are formed such that the tips of the iron cores 61-1, 61-2, 61-3, 61-4, 61-5, and 61-6 taper toward the center along the radial direction. A gap 20 is formed between the iron core 61-1 and the iron core 61-2, the iron core 61-2 and the iron core 61-3, the iron core 61-3 and the iron core 61-4, the iron core 61-4 and the iron core 61-5, the iron core 61-5 and the iron core 61-6, and the iron core 61-6 and the iron core 61-1, which are arranged approximately adjacent to one another in the circumferential direction. On each of the iron cores 61-1, 61-2, 61-3, 61-4, 61-5 and 61-6, a first gap counter surface 21 is formed which is opposite to the iron core arranged adjacent to one side of the respective iron core, and a second gap counter surface 22 is formed which is opposite to the iron core arranged adjacent to the other side of the respective iron core.More specifically, a first gap counter surface 21 opposite to the iron core 61-2 disposed adjacent to one side of the respective iron core 61-1, and a second gap counter surface 22 opposite to the iron core 61-6 disposed adjacent to the other side of the respective iron core 61-1 are formed on the iron core 61-1. A first gap counter surface 21 opposite to the iron core 61-3 disposed adjacent to one side of the respective iron core 61-2, and a second gap counter surface 22 opposite to the iron core 61-1 disposed adjacent to the other side of the respective iron core 61-2 are formed on the iron core 61-2. On the iron core 61-3, a first gap counter surface 21, which is opposite to the iron core 61-4 arranged next to one side of the respective iron core 61-3, and a second gap counter surface 22, which is opposite to the iron core 61-2 arranged next to the other side of the respective iron core 61-3, are formed.On the iron core 61-4, a first gap counter surface 21 is formed, which faces the iron core 61-5 arranged adjacent to one side of the respective iron core 61-4, and a second gap counter surface 22 is formed, which faces the iron core 61-3 arranged adjacent to the other side of the respective iron core 61-4. On the iron core 61-5, a first gap counter surface 21 is formed, which faces the iron core 61-6 arranged adjacent to one side of the respective iron core 61-5, and a second gap counter surface 22 is formed, which faces the iron core 61-4 arranged adjacent to the other side of the respective iron core 61-5. On the iron core 61-6, a first gap counter surface 21, which is opposite to the iron core 61-1 arranged next to one side of the respective iron core 61-6, and a second gap counter surface 22, which is opposite to the iron core 61-5 arranged next to the other side of the respective iron core 61-6, are formed. .

[0062] Thus, in the eleventh embodiment, as in the tenth embodiment described above, with two iron cores arranged side by side, the first gap counter surface 21 of one iron core is opposite the second gap counter surface 22 of the other iron core and the first gap counter surface 21 has a larger surface dimension than the second gap counter surface 22.

[0063] Fig. 19A is an overall sectional view showing a reactor according to the twelfth embodiment not according to the present invention, and showing an example in which windings are wound around all the iron cores. Fig. Figure 19B is an overall sectional view showing the reactor according to the twelfth embodiment, showing an example in which windings are wound around a portion of the iron cores. The reactor 1 according to the twelfth embodiment is implemented as a single-phase reactor having a square column shape. Fig. In the example shown in Fig. 19A, iron cores 62-1, 62-2, 62-3, and 62-4 of four poles are arranged approximately side by side in the circumferential direction, and windings 13 are wound around all of these iron cores. A gap 20 is formed between the iron core 62-1 and the iron core 62-2, between the iron core 62-2 and the iron core 62-3, between the iron core 62-3 and the iron core 62-4, and between the iron core 62-4 and the iron core 62-1, which are arranged approximately side by side in the circumferential direction. On each of the iron cores 62-1, 62-2, 62-3 and 62-4, a first gap counter surface 21 is formed which is opposite to the iron core arranged adjacent to one side of the respective iron core, and a second gap counter surface 22 is formed which is opposite to the iron core arranged adjacent to the other side of the respective iron core.More specifically, a first gap counter surface 21 opposite the iron core 62-2 disposed adjacent to one side of the respective iron core 62-1 and a second gap counter surface 22 opposite the iron core 62-4 disposed adjacent to the other side of the respective iron core 62-1 are formed on the iron core 62-1. A first gap counter surface 21 opposite the iron core 62-3 disposed adjacent to one side of the respective iron core 62-2 and a second gap counter surface 22 opposite the iron core 62-1 disposed adjacent to the other side of the respective iron core 62-2 are formed on the iron core 62-2. On the iron core 62-3, a first gap counter surface 21, which is opposite to the iron core 62-4 arranged next to one side of the respective iron core 62-3, and a second gap counter surface 22, which is opposite to the iron core 62-2 arranged next to the other side of the respective iron core 62-3, are formed.Formed on the iron core 62-4 are a first gap counter surface 21, which faces the iron core 62-1 arranged adjacent to one side of the respective iron core 62-4, and a second gap counter surface 22, which faces the iron core 62-3 arranged adjacent to the other side of the respective iron core 62-4. Thus, in the twelfth embodiment, as in the eleventh embodiment described above, with two iron cores arranged adjacent to one another, the first gap counter surface 21 of one iron core faces the second gap counter surface 22 of the other iron core, and the first gap counter surface 21 has a larger surface dimension than the second gap counter surface 22. In the embodiment shown in FIG. Fig. 19B, the iron cores 62-1, 62-2, 62-3 and 62-4 of four poles are arranged approximately in the circumferential direction, and are wound around two of the four iron cores (in the illustrated example, the reference numerals 62-1 and 62-3) windings 13. Since the other structural elements correspond to the Fig. 19A are the same, the same structural elements are designated by the same reference numerals and a detailed explanation of these structural elements is omitted.

[0064] Fig. 20A is an overall sectional view showing a reactor according to the thirteenth embodiment not according to the present invention, and showing an example in which windings are wound around all the iron cores. Fig. Fig. 20B is an overall sectional view showing the reactor according to the thirteenth embodiment, showing an example in which windings are wound around a part of the iron cores. The reactor 1 according to the thirteenth embodiment is constructed as described with reference to Fig. 19A and Fig. 19B, the twelfth embodiment is designed as a single-phase reactor with the shape of a square column, but the shape of the iron cores is different from the twelfth embodiment. Fig. In the example shown in Fig. 20A, iron cores 63-1, 63-2, 63-3, and 63-4 of four poles are arranged approximately side by side in the circumferential direction, and windings 13 are wound around all of these iron cores. A gap 20 is formed between the iron core 63-1 and the iron core 63-2, between the iron core 63-2 and the iron core 63-3, between the iron core 63-3 and the iron core 63-4, and between the iron core 63-4 and the iron core 63-1, which are arranged approximately side by side in the circumferential direction. On each of the iron cores 63-1, 63-2, 63-3 and 63-4, a first gap counter surface 21 is formed which is opposite to the iron core arranged adjacent to one side of the respective iron core, and a second gap counter surface 22 is formed which is opposite to the iron core arranged adjacent to the other side of the respective iron core.More specifically, a first gap counter surface 21 opposite the iron core 62-2 disposed adjacent to one side of the respective iron core 63-1, and a second gap counter surface 22 opposite the iron core 63-4 disposed adjacent to the other side of the respective iron core 63-1 are formed on the iron core 63-1. A first gap counter surface 21 opposite the iron core 63-3 disposed adjacent to one side of the respective iron core 63-2, and a second gap counter surface 22 opposite the iron core 63-1 disposed adjacent to the other side of the respective iron core 63-2 are formed on the iron core 63-2. On the iron core 63-3, a first gap counter surface 21, which is opposite to the iron core 63-4 arranged next to one side of the respective iron core 63-3, and a second gap counter surface 22, which is opposite to the iron core 63-2 arranged next to the other side of the respective iron core 63-3, are formed.Formed on the iron core 63-4 are a first gap counter surface 21, which faces the iron core 63-1 arranged adjacent to one side of the respective iron core 63-4, and a second gap counter surface 22, which faces the iron core 63-3 arranged adjacent to the other side of the respective iron core 63-4. Thus, in the thirteenth embodiment, as in the twelfth embodiment described above, when two iron cores are arranged adjacent to one another, the first gap counter surface 21 of one iron core faces the second gap counter surface 22 of the other iron core, and the first gap counter surface 21 has a larger surface dimension than the second gap counter surface 22. In the embodiment shown in FIG. Fig. 20B, the iron cores 63-1, 63-2, 63-3 and 63-4 of four poles are arranged approximately in the circumferential direction, and are wound around two of the four iron cores (in the illustrated example, the reference numerals 63-1 and 63-3) windings 13. Since the other structural elements correspond to the Fig. 20A are the same, the same structural elements are designated by the same reference numerals and a detailed explanation of these structural elements is omitted.

[0065] Fig. 21A is an overall sectional view showing a reactor according to the fourteenth embodiment not according to the present invention. Fig. Fig. 21B is a view showing the reactor according to the fourteenth embodiment, and an enlarged sectional view of the position within the dot-dashed line in Fig. 21A. The reactor 1 according to the fourteenth embodiment is implemented as a three-phase reactor having the shape of a square column. According to the fourteenth embodiment, the reactor 1 includes a plurality of first iron cores 15-1, 15-2, and 15-3 having two first gap counter surfaces 21, a plurality of second iron cores 16-1, 16-2, and 16-3 having two second gap counter surfaces 22 as surfaces opposite the first gap counter surfaces 21, and windings 13. The first iron cores 15-1, 15-2, and 15-3 are arranged adjacent to one another approximately in the circumferential direction. The second iron cores 16-1, 16-2, and 16-3 are also arranged adjacent to one another approximately in the circumferential direction. As shown in Fig. 21A and Fig. 21B, gaps 20 are formed between the first iron core 15-1 and the second iron core 16-1, between the second iron core 16-1 and the first iron core 15-2, between the first iron core 15-2 and the second iron core 16-2, between the second iron core 16-2 and the first iron core 15-3, between the first iron core 15-3 and the second iron core 16-3, and between the second iron core 16-3 and the first iron core 15-1, which are arranged approximately side by side in the circumferential direction. Here, the second iron core 16-1 is arranged such that the second gap counter surfaces 22 of this second iron core 16-1 are each opposite the first gap counter surface 21 of the iron core 15-1 adjacent to this second iron core 16-1 and the first gap counter surface 21 of the first iron core 15-2 adjacent to this second iron core 16-1 via a gap 20.The second iron core 16-2 is arranged such that the second gap counter surfaces 22 of this second iron core 16-2 each lie across a gap 20 opposite the first gap counter surface 21 of the iron core 15-2 adjacent to this second iron core 16-2 and the first gap counter surface 21 of the first iron core 15-3 adjacent to this second iron core 16-2. The second iron core 16-3 is arranged such that the second gap counter surfaces 22 of this second iron core 16-3 each lie across a gap 20 opposite the first gap counter surface 21 of the iron core 15-1 adjacent to this second iron core 16-3 and the first gap counter surface 21 of the first iron core 15-3 adjacent to this second iron core 16-3. The windings 13 are wound around the second iron cores 16-1, 16-2, and 16-3. In the fourteenth embodiment, one of the first gap counter surface 21 and the second gap counter surface 22 has a larger surface dimension than the other.In . Fig. 21A and Fig. 21B shows an exemplary embodiment in which the first gap counter surface 21 has a larger surface dimension than the second gap counter surface 22. The number of first iron cores and second iron cores is determined by the number of poles of the choke coil 1. For example, if the number of poles is two, the number of first iron cores and second iron cores is two each, and if the number of poles is six, the number of first iron cores and second iron cores is six each. In the illustrated example, the number of poles of the choke coil 1 is set to three, but the number of poles itself does not limit the present embodiment, and a different number of poles is also possible. Fig. 21A and Fig. The shape of the first iron cores 15-1, 15-2, and 15-3 and the second iron cores 16-1, 16-2, and 16-3 shown in Fig. 21B is exemplary; as long as the first gap counter surface 21 and the second gap counter surface 22 satisfy the relationship described above, any shape is possible.

[0066] Fig. 22A is an overall sectional view showing a reactor according to the fifteenth embodiment not according to the present invention. Fig. Fig. 22B is a view showing the reactor according to the fifteenth embodiment, and an enlarged sectional view of the position within the dot-dashed line in Fig. 22A. The reactor 1 according to the fifteenth embodiment is designed as a three-phase reactor having the shape of a square column. According to the fifteenth embodiment, the reactor 1 comprises a plurality of second iron cores 18-1, 18-2, and 18-3 having two second gap counter surfaces 22, a first iron core 17 having first gap counter surfaces 21 in the same number as the total number (in the case of Fig. 22A and Fig. 22B shown example six) of the second gap counter surfaces 22 of the plurality of second iron cores 18-1, 18-2 and 18-3, and windings 13. The second iron cores 18-1, 18-2 and 18-3 are arranged approximately side by side in the circumferential direction such that each of the second gap counter surfaces 22 of a respective second iron core is opposite one of the first gap counter surfaces 21 of the first iron core 17 via a gap 20. That is, as in Fig. 22A and Fig. As shown in Figure 22B, a gap 20 is formed between the second iron core 18-1 and the first iron core 17, between the second iron core 18-2 and the first iron core 17, and between the second iron core 18-3 and the first iron core 17, which are arranged approximately adjacent to each other in the circumferential direction. The windings 13 are wound on the second iron cores 18-1, 18-2, and 18-3. In the fifteenth embodiment, one of the first gap counter surface 21 and the second gap counter surface 22 has a larger surface dimension than the other. Fig. 22A and Fig. 22B shows an exemplary embodiment in which the first gap counter surface 21 has a larger surface dimension than the second gap counter surface 22. The number of first gap counter surfaces of the first iron core and the second iron cores is determined by the number of poles of the choke coil 1. For example, if the number of poles is two, the number of first gap counter surfaces 21 of the first iron core is four and the number of second iron cores is two; and if the number of poles is six, the number of first gap counter surfaces 21 of the first iron core is twelve and the number of second iron cores is six. In the illustrated example, the number of poles of the choke coil 1 is set to three, but the number of poles itself does not limit the present embodiment, and a different number of poles is also possible. Fig. 22A and Fig. The shape of the first iron core and the second iron cores 16-1, 16-2, and 16-3 shown in Fig. 22B is exemplary; as long as the first gap counter surface 21 and the second gap counter surface 22 satisfy the relationship described above, any shape is possible.

[0067] As modifications of the tenth to fifteenth embodiments described above, the iron cores positioned on the outer circumference may be in contact at locations other than the first gap counter surfaces and second gap counter surfaces or may be formed integrally; and this will be explained below with reference to Fig. 23 to Fig. 28 explained.

[0068] Fig. Fig. 23 is an overall sectional view showing a modification of the reactor according to the tenth embodiment not according to the invention. In this modification, the iron cores 14-1, 14-2, and 14-3 in the reactor 1 according to the embodiment described with reference to Fig. 17A and Fig. 17B, ​​the first gap counter surfaces 21 and the second gap counter surfaces 22 are in contact at locations other than the first gap counter surfaces 21 and the second gap counter surfaces 22, or they are made in one piece, whereby they are combined to form the iron core 14. Since the further structural elements correspond to the Fig. 17A and Fig. 17B are the same, the same structural elements are provided with the same reference numerals and a detailed explanation of these structural elements is omitted.

[0069] Fig. Fig. 24 is an overall sectional view showing a modification of the reactor according to the eleventh embodiment not according to the invention. In this modification, the iron cores 61-1, 61-2, 61-3, 61-4, 61-5, and 61-6 in the reactor 1 according to the embodiment described with reference to Fig. 18 explained eleventh embodiment at locations other than the first gap counter surfaces 21 and second gap counter surfaces 22 in contact or they are made in one piece, whereby they are combined to form an iron core 61. Since the further construction elements in Fig. 18 are the same, the same structural elements are provided with the same reference numerals and a detailed explanation of these structural elements is omitted.

[0070] Fig. 25A is an overall sectional view showing a modification of the reactor according to the twelfth embodiment not according to the present invention, and showing an example in which windings are wound around all the iron cores. Fig. Fig. 25B is an overall sectional view showing the modification of the reactor according to the twelfth embodiment, and shows an example in which windings are wound around a part of the iron cores. In the present modification, the iron cores 62-1, 62-2, 62-3, and 62-4 are arranged in the reactor 1 according to the embodiment described with reference to Fig. Fig. 19A and Fig. 19B explained twelfth embodiment at locations other than the first gap counter surfaces 21 and second gap counter surfaces 22 or they are made in one piece, whereby they are combined to form an iron core 62. Since the further structural elements correspond to the Fig. 19A and Fig. 19B are the same, the same structural elements are provided with the same reference numerals and a detailed explanation of these structural elements is omitted.

[0071] Fig. 26A is an overall sectional view showing a modification of the reactor according to the thirteenth embodiment not according to the present invention, and showing an example in which windings are wound around all the iron cores. Fig. Fig. 26B is an overall sectional view showing the modification of the reactor according to the thirteenth embodiment, and shows an example in which windings are wound around a part of the iron cores. In the present modification, the iron cores 63-1, 63-2, 63-3, and 63-4 are arranged in the reactor 1 according to the embodiment described with reference to Fig. 20A and Fig. 20B explained thirteenth embodiment at locations other than the first gap counter surfaces 21 and second gap counter surfaces 22 in contact or they are made in one piece, whereby they are combined to form an iron core 63. Since the further structural elements correspond to the Fig. 20A and Fig. 20B are the same, the same structural elements are provided with the same reference numerals and a detailed explanation of these structural elements is omitted.

[0072] Fig. Fig. 27 is an overall sectional view showing a modification of the reactor according to the fourteenth embodiment not according to the invention. In this modification, the second iron cores 16-1, 16-2, and 16-3 are arranged in the reactor 1 according to the embodiment described with reference to Fig. 21A and Fig. 21B, the first gap counter surfaces 21 and the second gap counter surfaces 22 are in contact at locations other than the first gap counter surfaces 21 and the second gap counter surfaces 22, or they are made in one piece, whereby they are combined to form the iron core 16. Since the further structural elements correspond to the Fig. 21A and Fig. 21B are the same, the same structural elements are provided with the same reference numerals and a detailed explanation of these structural elements is omitted.

[0073] Fig. Fig. 28 is an overall sectional view showing a modification of the reactor according to the fifteenth embodiment not according to the invention. In this modification, the second iron cores 18-1, 18-2, and 18-3 are arranged in the reactor 1 according to the embodiment described with reference to Fig. 22A and Fig. 22B, the first gap counter surfaces 21 and the second gap counter surfaces 22 are in contact at locations other than the first gap counter surfaces 21 and the second gap counter surfaces 22, or they are made in one piece, whereby they are combined to form an iron core 18. Since the further structural elements correspond to the Fig. 22A and Fig. 22B are the same, the same structural elements are designated by the same reference numerals and a detailed explanation of these structural elements is omitted.

[0074] The reactor 1 according to each of the above-described embodiments of the present invention can be used in a motor drive device as at least one of an AC reactor on the AC input side of a rectifier that converts AC power input from an AC power source into DC power, a smoothing reactor on the DC output side of the rectifier, or a reactor forming an LC filter on the AC output side of an inverter that converts the DC power output from the rectifier into AC power for motor driving. This will be explained with reference to Fig. 29 explained in detail.

[0075] Fig.29 is a view showing a motor driving device provided with reactors according to one form of the present invention. The motor driving device 1000 includes a rectifier 1001 that converts AC power supplied from an AC power source 1003 into DC power and outputs it to a DC link in which a DC capacitor 1005 is formed, and an inverter 1002 that converts and outputs the DC power output from the rectifier 1001 into AC power for motor driving, and controls the speed, torque, or position of a rotor of a motor 1004 connected to the AC output side of the inverter 1002.The rectifier 1001 includes, on its AC input side, a choke coil 1 according to one form of the present invention as an AC choke coil, and, on its DC output side, a choke coil 1 according to one form of the present invention as a smoothing choke coil. The inverter 1002 includes, on its AC output side, choke coils 1 according to one form of the present invention as choke coils, forming an LC filter 1006 on the AC output side.In the illustrated example, the reactor 1 according to the present invention is used for a total of three types of reactors - the AC reactor formed on the AC input side of the rectifier 1001, the smoothing reactor formed on the DC output side of the rectifier 1001, and the reactors forming the LC filter 1006 on the AC output side of the inverter 1002 - but it is not essential to use the reactor 1 according to one form of the present invention for all of these three types, and it may be used for one or two of these three types of reactors.

[0076] According to one form of the present invention, a reactor in which more magnetic energy can be stored and the eddy current loss can be reduced while suppressing the generation of a stray magnetic flux in the vicinity of the gaps, as well as a rectifier provided therewith, an LC filter provided therewith, and a motor driving device provided therewith can be implemented.

[0077] According to one form of the present invention, in a reactor comprising a plurality of iron cores and windings wound around any of the plurality of iron cores, by a structure in which, when the iron cores are adjacent to each other, the gap counter surface of one of the iron cores has a larger area than the gap counter surface of the other of the iron cores, more magnetic energy can be stored and eddy current loss can be reduced while suppressing the generation of stray magnetic flux in the vicinity of the gaps.

Claims

[1] Choke coil (1), comprising several iron cores (11, 12); and Windings (13) wound around any of the plurality of iron cores, wherein a gap (20) is formed between two opposing iron cores, and a gap counter surface (21) of one (11) of the iron cores has a larger surface dimension than a gap counter surface (22) of the other (12) of the iron cores, gaps (20) are formed between iron cores arranged approximately side by side in the circumferential direction, on each iron core, a first gap counter surface (21) is formed, which is opposite an iron core arranged next to one side of the respective iron core, and a second gap counter surface (22) is formed, which is opposite an iron core arranged next to the other side of the respective iron core, in the case of two iron cores arranged side by side, the first gap counter surface (21) of one iron core is opposite the second gap counter surface (22) of the other iron core, and the first gap counter surface (21) has a larger surface dimension than the second gap counter surface (22), wherein the first gap counter surface (21) has a recessed shape of one iron core and the second gap counter surface (22) of the other iron core has a projecting shape, wherein the surroundings of the outer edge of the first gap counter surface (21) of the first iron core and the axial direction form an acute angle to the interior of the first iron core, the vicinity of the outer edge of the second gap counter surface (22) of the second iron core and the axial direction form an obtuse angle to the interior of the second iron core, wherein the first iron core (11) in the vicinity of the gap (20) has a projection portion (40) such that the thickness of the first iron core (11) in the region close to the gap (20) is thicker than the region of the first iron core (11) in the vicinity of this gap (20) and the second iron core (12). [2] Choke coil (1), comprising several iron cores (11, 12); and Windings (13) wound around any of the plurality of iron cores, wherein a gap (20) is formed between two opposing iron cores, and a gap counter surface (21) of one (11) of the iron cores has a larger surface dimension than a gap counter surface (22) of the other (12) of the iron cores, the plurality of iron cores comprise a plurality of first iron cores and a plurality of second iron cores, each having a first gap counter surface (21) and a second gap counter surface (22) as surfaces which are opposite to each other, wherein the first iron cores are arranged approximately circumferentially next to each other, and the second iron cores are arranged next to one another approximately in the circumferential direction such that the second gap counter-surface (22) of a respective second iron core is opposite the first gap counter-surface (21) of a first iron core adjacent to this second iron core, wherein the windings (13) are wound around the second iron cores, and the first gap counter-surface (21) or the second gap counter-surface (22) has a larger surface dimension than the opposite other, wherein on the first gap counter-surface (21) alternating recessed shapes and projecting shapes are formed in a number one less than that of the recessed shapes, and on the second gap counter-surface (22) alternating recessed shapes and projecting shapes are formed in a number one greater than that of the recessed shapes. [3] Choke coil (1), comprising several iron cores (11, 12); and windings (13) wound around any of the plurality of iron cores, wherein a gap (20) is formed between two opposing iron cores, the plurality of iron cores comprise a plurality of second iron cores having two second gap counter surfaces (22) and a first iron core having first gap counter surfaces in the same number as the total number of second gap counter surfaces of the second iron cores, the second iron cores are arranged adjacent to one another approximately in the circumferential direction such that each of the second gap counter surfaces (22) of a respective second iron core is opposite one of the first gap counter surfaces (21) of the first iron core, the windings (13) are wound around the second iron cores, and one of the first gap counter surfaces (21) and the second gap counter surfaces (22) has a larger surface dimension than the other, wherein on the first gap counter surface (21) alternately recessed shapes and projecting shapes are formed in a number one less than that of the recessed shapes, and on the second gap counter surface (22) alternately recessed shapes and projecting shapes are formed in a number one greater than that of the recessed shapes. [4] Choke coil (1) according to one of claims 1 to 3, wherein the individual iron cores are in contact at locations other than the gap counter surfaces or are designed in one piece. [5] Choke coil (1) according to one of the preceding claims 1 to 4, wherein the bottom portion of the recessed shape has the shape of a curved surface, and the apex portion of the projecting shape has the shape of a curved surface. [6] Rectifier (1001), wherein the rectifier (1001) is provided with a choke coil (1) according to one of claims 1 to 5, wherein the choke coil (1) is designed as an AC choke coil on the AC input side of the rectifier (1001) or as a smoothing choke coil on the DC output side of the rectifier (1001). [7] LC filter (1006) provided with a choke coil (1) according to one of claims 1 to 5. [8] A motor driving device (1000), wherein the reactor (1) according to any one of claims 1 to 5 is configured as at least one of an AC reactor on the AC input side of a rectifier (1001) that converts AC power input from an AC power source (1003) into DC power, a smoothing reactor on the DC output side of the rectifier (1001), or a reactor forming an LC filter (1006) on the AC output side of an inverter (1002) that converts DC power output from the rectifier (1001) into AC power for motor driving.

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