Title of Invention : Wound Iron Core
Technical field
[0001]
　The present disclosure relates to wound cores.
Background technology
[0002]
　Wound iron cores are used as magnetic cores for transformers, reactors, noise filters, and the like. In the field of transformers, conventionally, from the viewpoint of high efficiency, reduction of iron loss has been one of the important issues, and studies on reduction of iron loss have been made from various viewpoints.
[0003]
　Transformers and the like using a wound core are widely used in electrical and electronic equipment, but they generate noise due to magnetostriction that occurs when a magnetic field is applied to the wound core. Therefore, researches on noise reduction by reducing magnetostriction are being actively conducted.
[0004]
　For example, in Japanese Unexamined Patent Application Publication No. 2017-84889, a circumferential band is wound in the winding direction of the steel plate around the outer periphery of the core made of a steel plate wound in a coil, and the surface side of the circumferential band is wound around the core. A low-noise wound transformer is disclosed in which a lamination-direction band with a vibration loss factor η>0.01 is arranged between the winding and the iron core.
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0005]
　By the way, in order to reduce the iron loss of the wound core, there is known a technique of forming the wound core from a plurality of electromagnetic steel sheets. However, the use of an electromagnetic steel sheet tends to cause noise due to magnetostriction.
　In recent years, there has been an increasing demand for noise reduction of wound cores by reducing magnetostriction. There is room for improvement in reducing the noise of the wound core.
[0006]
　An object of the present disclosure is to provide a wound core in which iron loss is reduced and noise is suppressed.
Means to solve problems
[0007]
　The present inventors focused their attention on the gap between the laminated magnetic steel sheets while earnestly studying how to reduce the noise of the wound core. When a time-varying magnetic field is applied to a transformer using a wound core, the magnetic steel sheets vibrate in the lamination direction due to the magnetostriction that occurs in the magnetic steel sheets. Due to this vibration, compressional waves of air are generated from the gaps between the electromagnetic steel plates. This compressional wave of air is recognized as sound. The present inventors have found that the gap between the magnetic steel sheets becomes large at the bent portion of the wound core, and that the gap at the bent portion greatly affects the noise of the transformer. Then, the inventors found that noise can be reduced by reducing the gap of the bent portion, and as a result of further studies, the present disclosure was made.
[0008]
　The gist of one aspect of the present disclosure based on the above knowledge is as follows.
　A wound core according to one aspect of the present disclosure includes a laminated body in which a plurality of electromagnetic steel sheets are annularly laminated in a side view, and the laminated body includes a plurality of bent portions and a plurality of bent portions positioned between the adjacent bent portions. and at least one of the plurality of bent portions is such that the space factor of the electromagnetic steel sheets in the bent portion is the average space area of ​​the electromagnetic steel sheets in the plurality of side portions. It is a bending portion with a high space factor, which is higher than the ratio.
Effect of the invention
[0009]
　According to the present disclosure, it is possible to provide a wound core with reduced iron loss and suppressed noise.
Brief description of the drawing
[0010]
1 is a side view showing an example of a wound core according to a first embodiment of the present disclosure; FIG.
2 is a diagram showing an example of compression means provided in the wound core according to the first embodiment, and is an exploded perspective view of part X in FIG. 1. FIG.
[Fig. 3] Fig. 3 is a schematic diagram showing a bent portion before and after compression means is applied.
4 is a side view showing an example of a wound core according to a second embodiment of the present disclosure; FIG.
5 is a graph showing the relationship between the average space factor of electromagnetic steel sheets and the sound pressure at four bent portions in test examples. FIG.
6 is a graph showing the relationship between the average space factor of electromagnetic steel sheets and the sound pressure at four bent portions in test examples. FIG.
MODE FOR CARRYING OUT THE INVENTION
[0011]
　Embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the present specification and drawings, constituent elements having substantially the same functional configuration are denoted by the same reference numerals, thereby omitting redundant description. Also, the ratios and dimensions of each component in the drawings do not represent the actual ratios and dimensions of each component.
[0012]

　First, a wound core according to a first embodiment will be described with reference to FIGS. 1 to 3. FIG. FIG. 1 is a side view showing an example of a wound core according to this embodiment. FIG. 2 is a diagram showing an example of compression means provided in the wound core, and is an exploded perspective view of the X section in FIG. 1 . FIG. 3 is a schematic diagram showing a bent portion before and after application of compression means. In addition, below, the case where the electromagnetic steel sheet S is seen from the side is referred to as a side view. The lamination direction of the electromagnetic steel sheets S is appropriately referred to as the "lamination direction". Further, the plate width direction of the electromagnetic steel sheet S is appropriately referred to as the “plate width direction”. Further, the winding direction of the electromagnetic steel sheet S is appropriately referred to as "winding direction".
[0013]
　As shown in FIG. 1, the wound core 1 according to the present embodiment includes a laminate 2 in which a plurality of electromagnetic steel sheets S are annularly laminated in a side view (in other words, when the wound core 1 is viewed from the side). . In other words, the laminate 2 is formed by laminating a plurality of annularly formed electromagnetic steel sheets S in the plate thickness direction. This laminate 2 has a plurality of bent portions 21 and a plurality of side portions 22 located between the bent portions 21 adjacent to each other. In addition, the side surface here means the surface formed by the side surface of the electromagnetic steel sheets S laminated.
[0014]
　As shown in FIG. 1 , the laminate 2 is formed by laminating electromagnetic steel sheets S into an octagonal shape when viewed from the side, and has a plurality of bent portions 21 and a plurality of side portions 22 . Specifically, the laminate 2 has a rectangular shape in which the innermost magnetic steel sheet S is bent to form four corners 21A, and the magnetic steel sheets S positioned on the outer periphery of the innermost magnetic steel sheet S are bent to form four corners 21A. S is bent at the corner 21A of the innermost magnetic steel sheet S, and laminated so as to form two corners 21B. Here, the bent portion 21 of the laminate 2 is a substantially triangular region formed by connecting one corner portion 21A and two corner portions 21B formed by bending the electromagnetic steel sheet S at the corner portion 21A with a straight line. part. Note that the present disclosure is not limited to this configuration. For example, when there are two adjacent corners 21A, the bent part 21 of the laminate 2 is a substantially trapezoidal region formed by connecting the two corners 21A and the two corners 21B with straight lines. may be Moreover, the side portion 22 of the laminate 2 is a substantially linear portion positioned between the adjacent bent portions 21 . Thus, the laminate 2 of this embodiment has four bent portions 21 and four side portions 22 . When viewed from the side of the electromagnetic steel sheet S, the laminate 2 has an octagonal shape with eight corners 21B on the outer periphery. On the other hand, the laminate 2 has a rectangular shape with four corners 21A on the inner circumference.
[0015]
　The space factor of the electromagnetic steel sheets S in each of the four bent portions 21 of the laminate 2 is substantially constant. Moreover, the space factor of the electromagnetic steel sheets S in each of the four side portions 22 of the laminate 2 is substantially constant. In the present embodiment, the space factor of the electromagnetic steel sheets S in each of the four bent portions 21 of the laminate 2 is substantially constant, but the space factors of the electromagnetic steel sheets S in the four bent portions 21 are different. may be In this case, the space factor of the electromagnetic steel sheets S in the bent portion 21 can be adjusted by the compressing means 3, which will be described later.
[0016]
　The space factor of the bent portion 21 and the side portion 22 of the laminate 2 can be calculated based on JIS C 2550-5:2011. JIS C 2550-5:2011 corresponds to IEC 60404-13: 1995, "Magnetic materials-Part 13: Methods of measurement of density, resistance and stacking factor of electrical steel".
[0017]
　For the laminate 2, for example, an existing grain-oriented electrical steel sheet or an existing non-oriented electrical steel sheet can be used, but it is preferable to use a grain-oriented electrical steel sheet. By using grain-oriented electrical steel sheets for the laminate 2, it is possible to reduce the hysteresis loss in the iron loss, and the iron loss of the wound core 1 can be further reduced.
[0018]
　The thickness of the magnetic steel sheet S is not particularly limited, and may be, for example, 0.20 mm or more or 0.40 mm or less. By using the magnetic steel sheet S having a small thickness (thin), eddy current is less likely to occur in the plate thickness plane of the magnetic steel sheet S, and eddy current loss among core losses can be further reduced. As a result, the iron loss of the wound core 1 can be reduced. The thickness of the electromagnetic steel sheet S is preferably 0.18 mm or more. Moreover, the thickness of the magnetic steel sheet S is preferably 0.35 mm or less, more preferably 0.27 mm or less.
[0019]
　The laminated electromagnetic steel sheets S are insulated from each other. Preferably, the surfaces of the electromagnetic steel sheets S are insulated from each other by being subjected to an insulation treatment. Since the layers of the electromagnetic steel sheets S are insulated, eddy currents are less likely to occur in the plate thickness plane of the electromagnetic steel sheets S, and eddy current loss can be reduced. As a result, the iron loss of the wound core 1 can be further reduced. For example, the surface of the electrical steel sheet S is preferably subjected to an insulation treatment using an insulation coating liquid containing colloidal silica and phosphate.
[0020]
　In addition, the wound core 1 includes compression means 3 for compressing the bending portion 21 in the stacking direction of at least one of the plurality of bending portions 21 of the electromagnetic steel sheets S. Specifically, the compressing means 3 compresses the bent portion 21 from both sides in the lamination direction of the electromagnetic steel sheets S (in other words, the bent portion 21 from the inner peripheral side and the outer peripheral side of the bent portion 21 in the lamination direction of the electromagnetic steel sheets S). Compress.
[0021]
　The compression means 3 of this embodiment has an outer plate 31 , an inner plate 32 , bolts 33 and nuts 34 .
[0022]
　As shown in FIG. 2, an outer plate 31 and an inner plate 32 are arranged on the outer peripheral side and the inner peripheral side of the bent portion 21, respectively. In addition, the length of the outer plate 31 and the inner plate 32 along the plate width direction of the electromagnetic steel plates S constituting the laminate 2 is greater than the plate width of the electromagnetic steel plates S constituting the laminate 2, and Insertion holes 31A and 32A into which bolts 33 are inserted are provided at both ends of the plate 32 in the longitudinal direction. In addition, the outer peripheral side and the inner peripheral side of the bent portion 21 here mean the outer peripheral side and the inner peripheral side of the bent portion 21 of the laminate 2 .
[0023]
　The inner plate 32 has a convex portion 32B extending in the longitudinal direction of the inner plate 32 according to the shape of the corner portion 21A so that no gap is formed between the inner plate 32 and the laminate 2 . The convex portion 32B is preferably made of a soft material capable of absorbing the vibration of the electromagnetic steel plate S. As shown in FIG. As a material for the projection 32B, it is preferable to use, for example, resin or wood.
[0024]
　The outer plate 31 and the inner plate 32 are arranged such that insertion holes 31A and 32A provided at both ends thereof protrude from the side surface of the bent portion 21 . Then, the bolts 33 are inserted into the insertion holes 31A of the outer plate 31 and the insertion holes 32A of the inner plate 32 corresponding to the insertion holes 31A, and the nuts 34 are screwed into the bolts 33, thereby separating the outer plate 31 and the inner plate 32. are concatenated. Then, the nut 34 is tightened, and the outer plate 31 and the inner plate 32 compress the bent portion 21 in the stacking direction. The outer plate 31 is an example of a first contact portion, the inner plate 32 is an example of a second contact portion, and the bolt 33 and the nut 34 are an example of a connecting portion.
　Therefore, the compression means 3 includes a first contact portion that contacts the outer peripheral side of the bent portion 21, a second contact portion that contacts the inner peripheral side of the bent portion, and the first contact portion and the second contact portion. The first contact portion and the second contact portion compress the bent portion 21 in the stacking direction of the electromagnetic steel sheets S under the restraining force of the connection portion. In other words, the plurality of electromagnetic steel sheets S forming the bent portion 21 are compressed in the stacking direction.
[0025]
　As described above, at least one bent portion 21 among the plurality of bent portions 21 is compressed in the stacking direction of the electromagnetic steel sheets S at the bent portion 21 by the compressing means 3 . Here, the bent portion 21 before applying the compressing means 3 has a gap between the electromagnetic steel plates S as schematically shown in FIG. 3(A). In general, the space factor of the electromagnetic steel sheets S in the bent portion 21 before applying the compressing means 3 is smaller than the space factor of the electromagnetic steel sheets S in the side portion 22 . On the other hand, in the bent portion 21 compressed in the stacking direction of the electromagnetic steel sheets S by the compressing means 3, the gap between the electromagnetic steel sheets S becomes smaller as shown in FIG. 3B. Thus, the compression means 3 can increase the space factor of the electromagnetic steel sheets S in the bent portion 21 . In this embodiment, by using the compressing means 3 , the space factor of the electromagnetic steel sheets S in the bent portion 21 can be made higher than the average space factor of the electromagnetic steel sheets S in the plurality of side portions 22 . As a result, when an alternating magnetic field is applied to wound core 1 in which the gap between electromagnetic steel sheets S at bent portion 21 is reduced, noise generated from the gap between electromagnetic steel plates S at bent portion 21 is reduced.
　In addition, the bent portion 21 in which the space factor of the electromagnetic steel sheets S is higher than the average space factor of the electromagnetic steel plates S in the plurality of side portions 22 corresponds to the high space factor bent portion of the present disclosure.
[0026]
　Further, the compression of the bent portion 21 by the compressing means 3 is preferably performed so that the space factor of the compressed bent portion 21 is 93% or more, and more preferably 96% or more. . When the space factor of the compressed bent portions 21 is 93% or more, the gaps between the electromagnetic steel sheets S are further reduced, and the noise of the wound core 1 to which the AC magnetic field is applied can be further reduced. When the space factor of the compressed bent portions 21 is 96% or more, the noise of the wound core 1 can be further reduced. The upper limit of the space factor of the compressed bent portion 21 is 100%.
[0027]
　The compressing means 3 may be provided on at least one bent portion 21 , but preferably provided on more bent portions 21 . By providing the compressing means 3 in a larger number of bent portions 21, the gaps in the entire bent portions 21 in the laminate 2 are reduced, and noise can be reduced. Moreover, it is more preferable that the compression means 3 be provided at all the bent portions 21 . By providing the compression means 3 in all the bent portions 21, the gaps between the electromagnetic steel sheets S are reduced in the entire laminate 2, and the noise of the wound core 1 to which the AC magnetic field is applied can be further reduced. Become.
[0028]
　Further, the outer plate 31, the inner plate 32, the bolt 33 or the nut 34 are made of non-magnetic material. As the non-magnetic material, it is preferable to use, for example, wood, resin, copper, brass, or the like. If the outer plate 31, the inner plate 32, the bolts 33, or the nuts 34 are non-magnetic, it is possible to prevent eddy currents from occurring in the compression means 3, and as a result, it is possible to prevent an increase in iron loss.
[0029]
　Moreover, the compressing means 3 preferably has an insulating washer (not shown). Since the compressing means 3 has an insulating washer, it is possible to prevent current from flowing through the outer plate 31, the inner plate 32, the bolt 33 and the nut 34 as a circuit. This prevents the current from generating a magnetic field, so that a stable magnetic field can be formed. As a result, an increase in iron loss is prevented. If the compression means 3 does not have an insulating washer, it is preferable that at least one of the outer plate 31, the inner plate 32, the bolt 33 or the nut 34 is an insulator. By using an insulator for at least one of the outer plate 31, the inner plate 32, the bolt 33, or the nut 34, no electric current flows to the compression means 3, and a stable magnetic field can be obtained, preventing an increase in iron loss. It becomes possible to As the insulating material, various known insulators such as natural rubber, epoxy resin, polyvinyl chloride or polyurethane insulating material can be used.
[0030]
　As described above, according to the present embodiment, at least one bent portion 21 out of the plurality of bent portions 21 is compressed in the stacking direction of the electromagnetic steel sheets S in the bent portion 21 by the compressing means 3, so that the compressed bent portion The gap between the electromagnetic steel plates S at 21 becomes smaller. As a result, when an alternating magnetic field is applied to the wound core 1, it is possible to reduce noise generated from this gap.
[0031]
　The wound core 1 according to this embodiment is applicable to, for example, a transformer. A transformer according to this embodiment includes a wound core 1 according to this embodiment, a primary winding, and a secondary winding. A magnetic flux is generated in the wound core 1 by applying an AC voltage to the primary winding, and a voltage is generated in the secondary winding due to a change in the generated magnetic flux. At least one of the bent portions 21 of the laminated body 2 of the wound core is compressed in the lamination direction of the electromagnetic steel sheets S at the bent portion 21 by the compressing means 3 . Therefore, the gap between the electromagnetic steel sheets S in the compressed bent portion 21 becomes smaller. As a result, it is possible to suppress the noise of the transformer.
[0032]

　Next, a wound core 1A according to a second embodiment will be described with reference to FIG. FIG. 4 is a side view showing an example of the wound core according to this embodiment. The wound core 1A, as shown in FIG. 4, includes a laminated body 2A and compression means 3A. The laminate 2A differs from the laminate 2 according to the first embodiment in that it has four linear corners 21A, but has the same basic configuration as the laminate 2 described in the first embodiment. A detailed description is omitted here. In addition, the same code|symbol is attached|subjected regarding the structure same as 1st Embodiment, and the description is abbreviate|omitted.
[0033]
　In the first embodiment, the compressing means 3 compresses the bent portion 21 in the stacking direction of the electromagnetic steel sheets S by receiving the restraining force of the connecting portion at the first contact portion and the second contact portion. , the compression means is not limited to the above configuration. The compression means may be, for example, in the form shown in FIG. As shown in FIG. 4 , the laminated body 2A of the wound core 1A has bent portions 21 at positions facing each other across the central axis C of the laminated body 2A in a side view. The compressing means 3A compresses the bent portion 21 by applying force to the bent portion 21 from the corner portion 21A. Specifically, the compressing means 3A includes a plurality of compressing members 35 for compressing the two bent portions 21 facing each other across the central axis C of the laminate 2A from the corners 21A in a side view. The compression member 35 is, for example, a substantially rod-shaped member that can be stretched and adjusted, and is a member that can be arbitrarily adjusted in length or a member made of an elastic body. The compression member 35 is, for example, a member having a turnbuckle. The compression member 35 is arranged on a straight line connecting two corners 21A facing each other across the central axis C in a side view inside the laminate 2A. By extending the compression member 35, the two bent portions 21 facing each other with the central axis C therebetween are compressed. Specifically, the compression member 35 presses the two bent portions 21 that face each other via the two corners 21A that face each other via the central axis C in a side view from the inner peripheral side to the outer peripheral side. As a result, the two opposing bent portions 21 are compressed in the stacking direction of the electromagnetic steel sheets S, respectively. As a result, the gap between the electromagnetic steel sheets S at the two compressed bent portions 21 becomes smaller, so that the noise of the wound core to which the AC magnetic field is applied can be reduced.
[0034]
　It is preferable that a plurality of compression members 35 be provided in the width direction of the electromagnetic steel sheets S constituting the laminate 2A. That is, a plurality of compression members 35 arranged on a straight line connecting two corners 21A facing each other via a central axis C in a side view are arranged in the plate width direction of the electromagnetic steel sheets S constituting the laminate 2A. , the two bent portions 21 facing each other across the central axis C are uniformly compressed in the sheet width direction of the electromagnetic steel sheets S forming the laminate 2A. This makes it possible to further reduce the noise of the wound core to which the AC magnetic field is applied.
[0035]
　The compression means 3A preferably has a plurality of compression members 35A and 35B for compressing two pairs of bent portions 21 facing each other across the central axis C in a side view. This makes it possible to further reduce the gaps between the magnetic steel sheets S in the wound core as a whole, and as a result, it is possible to further reduce the noise of the wound core 1A to which the AC magnetic field is applied. Furthermore, the compression means 3A includes a plurality of compression members 35A arranged on a straight line connecting a pair of corners 21A facing each other via the central axis C in a side view, and a plurality of compression members 35A arranged on a straight line connecting the other pair of corners 21A. A plurality of compression members 35B are arranged, and the plurality of compression members 35A and the plurality of compression members 35B are preferably arranged alternately in the sheet width direction of the electromagnetic steel sheet S. Thereby, the bent portion 21 is uniformly compressed in the height direction, and the space factor can be increased.
[0036]
　It should be noted that the compressing means 3A is preferably a non-magnetic material or an insulating material. If the compression means 3A is a non-magnetic material, it is possible to prevent generation of eddy current in the compression means 3, and as a result, it is possible to prevent an increase in iron loss. Further, if the compressing means 3A is an insulator, no electric current flows through the compressing means 3A, so that a stable magnetic field can be formed. As a result, an increase in iron loss is prevented.
[0037]
In
　the following, several modifications of the above embodiment of the present disclosure will be described. In addition, each modification described below may be applied to the above embodiment of the present disclosure independently, or may be applied in combination to the above embodiment of the present disclosure. Further, each modification may be applied instead of the configuration described in the above embodiment of the present disclosure, or may be additionally applied to the configuration described in the above embodiment of the present disclosure.
[0038]
　In the laminates 2 and 2A, when the average space factor (%) of the electromagnetic steel sheets S in the four side portions 22 is B, the average space factor A of the electromagnetic steel sheets S in the plurality of bent portions 21 is (B-4 .0)% or more. If the average space factor A is (B-4.0)% or more, the noise of the wound core can be reduced.
[0039]
　The pressure applied to the bent portion 21 is preferably within the range of 0.2 MPa or more and 4.0 MPa or less regardless of the mode of compression means. If the pressure applied to the bent portion 21 is within the above range, the noise is reduced and the iron loss is not increased. For example, in the wound core 1 according to the first embodiment, the pressure applied to the bent portion 21 can be managed by the tightening torque of the bolt 33 and nut 34 .
[0040]
　In the laminates 2 and 2A, when the average space factor (%) of the electromagnetic steel sheets S in the four side portions 22 is B, the occupancy of the electromagnetic steel sheets S in at least one bent portion 21 among the plurality of bent portions 21 is Regardless of the mode of compression means, it is preferable that the product ratio C is not less than B% and not more than (B+1)%. When the space factor C is B% or more and (B+1)% or less, the magnetic steel sheet S is not plastically deformed, and the space factor in the bent portion 21 can be increased. Since the magnetic steel sheet S is not plastically deformed, a magnetic field without disturbance is generated, and an increase in leakage magnetic flux can be suppressed. As a result, it is possible to suppress an increase in iron loss. Moreover, since the vibration between the layers of the electromagnetic steel sheets S in the bent portion 21 is suppressed, noise can also be suppressed.
[0041]
　Further, in each of the embodiments described above, the case where the outer periphery of the laminate is octagonal has been described, but the present disclosure is not limited to this. The perimeter of the laminate may be polygonal, square with rounded corners, oval, elliptical, or the like. For example, an oblong laminate is manufactured by winding an electromagnetic steel sheet. On the other hand, the octagonal laminate is manufactured by laminating a plurality of circularly bent electromagnetic steel sheets in the thickness direction. A laminate produced by laminating a plurality of electromagnetic steel sheets bent in an annular shape in the plate thickness direction tends to have a smaller space factor at the bent portion than a laminate produced by winding the electromagnetic steel sheets. Therefore, when applying the compressing means to the laminate, compared to the case of applying the compressing means to the laminate manufactured by winding the electromagnetic steel sheets, a plurality of circularly bent electromagnetic steel sheets are laminated in the thickness direction. A high noise reduction effect is likely to be obtained by applying compression means to the laminated body manufactured by In addition, as the number of times the magnetic steel sheet is bent increases, the space factor at the bent portion decreases. Therefore, since the effect of improving the space factor of the bent portion by the compression means is increased, the compression means is preferably applied to the octagonal laminate.
[0042]
　In the above-described embodiments, the laminates 2 and 2A have a quadrangular or octagonal inner circumference, but the present disclosure is not limited thereto, and the laminates 2 and 2A have other polygonal inner circumferences. , rounded square, oval, or oval. For example, when the inner periphery of the laminates 2 and 2A is octagonal, the portion connecting two adjacent vertices of the octagon becomes the corner, and when the inner periphery of the laminates 2 and 2A is oval, the arc-shaped portion is the corner. In the case where the inner perimeter of the laminates 2 and 2A is polygonal, square with rounded corners, oval, elliptical, or the like, the bent portion 21 is positioned between one adjacent side and the other side. , the magnetic steel sheets S are bent and laminated with respect to the extending direction of the magnetic steel sheets S on one side and the magnetic steel sheets S on the other side. In addition, the shape of the end portion of the compression means 3A described in the second embodiment can be a shape corresponding to the shape of the corner portion 21A. Thereby, the bent portion can be uniformly compressed.
[0043]
　Moreover, the inner periphery of the laminates 2 and 2A may have a shape corresponding to the shape of the outer periphery. For example, when the outer perimeter of the laminates 2 and 2A is octagonal, the inner perimeter may be octagonal. There may be.
[0044]
　The compressing means 3 shown in FIG. 1 and the compressing means 3A shown in FIG. 4 are merely examples, and the compressing means is not limited to the above mode as long as it can compress the bent portion 21 .
[0045]
　In addition, the space factor of at least one side portion 22 among the plurality of side portions 22 of the laminates 2 and 2A may be lowered. Specifically, by arranging a spacer or the like between the electromagnetic steel plates S on one side portion 22, the gap between the magnetic steel plates S on the side portion 22 can be increased. Thereby, the heat dissipation area of ​​the laminates 2 and 2A can be increased.
[0046]
　The wound core shown as a modified example can be applied to a transformer, like the wound core 1 of the first embodiment. In the transformer to which the wound core shown in this modified example is applied, similarly to the transformer to which the wound core 1 is applied, the gap between the electromagnetic steel sheets at the bent portion becomes smaller, so the noise of the transformer is suppressed.
[0047]
　Next, test examples of the present disclosure will be described. The conditions in this test example are one example of conditions adopted for confirming the feasibility and effect of the present disclosure, and the present disclosure is not limited to this one example of conditions. Various conditions can be adopted for the present disclosure as long as the purpose of the present disclosure is achieved without departing from the gist of the present disclosure.
[0048]
(Test Example 1)
　Grain-oriented electrical steel sheets having a thickness of 0.20 mm were laminated to prepare a laminate having four bent portions. A wound core was manufactured in which one of the four bends was compressed at the pressure shown in Table 1 using a wooden compression means. The manufactured wound core has the same configuration as that illustrated in FIG. A transformer with a capacity of 20 kVA was manufactured using the produced wound core. The lamination factor of the wound core used in the manufactured transformer was calculated based on JIS C 2550-5:2011. In addition, iron loss (no-load loss) and sound pressure of the manufactured transformer were measured according to JEC-2200. was measured. Table 1 shows values ​​of compressive force, space factor, sound pressure and iron loss. In addition, the space factor C in Table 1 indicates the space factor of the electromagnetic steel sheets in the bent portion compressed by the compressing means, and the space factor A indicates the average space factor of the electromagnetic steel sheets in the four bent portions. , the space factor B indicates the average space factor of the magnetic steel sheets in the four sides. Inventive examples in Table 1 refer to examples to which the present disclosure is applied, and comparative examples refer to examples to which the present disclosure is not applied.
[0049]
[table 1]

[0050]
　The space factor of one of the plurality of bent parts is higher than the average space factor of the magnetic steel sheets on the four sides, thereby reducing sound pressure and iron loss. .
[0051]
(Test Example 2)
　Grain-oriented electrical steel sheets having a thickness of 0.23 mm were laminated to prepare a laminate having four bent portions. A wound core was manufactured by compressing each of the four bent portions of this laminate with a pressure shown in Table 2 using a wooden compressing means. The manufactured wound core has the same configuration as that illustrated in FIG. Using this wound core, a transformer with a capacity of 20 kVA was manufactured. The lamination factor of the wound core used in the manufactured transformer was calculated based on JIS C 2550-5:2011. In addition, iron loss (no-load loss) and sound pressure were measured in the same manner as in Test Example 1 for the wound cores used in the manufactured transformers. Table 2 shows values ​​of compressive force, space factor, sound pressure and iron loss. Note that the average space factor A in Table 2 indicates the average space factor of the electromagnetic steel sheets at the four bent portions, and the average space factor B indicates the average space factor of the electromagnetic steel sheets at the four side portions. Also, FIG. 5 shows the relationship between the average space factor A and the sound pressure. Inventive examples in Table 2 refer to examples to which the present disclosure is applied, and comparative examples refer to examples to which the present disclosure is not applied.
[0052]
[Table 2]

[0053]
　As shown in Table 2, when the average space factor A, which is the average space factor of the electromagnetic steel sheets at the four bent portions, is (B-4.0)% or more, the sound pressure decreases and the iron Reduced losses. Moreover, as shown in FIG. 5, when the average space factor A was 96.0% or more, the sound pressure became smaller.
[0054]
(Test Example 3)
　Using grain-oriented electrical steel sheets with a thickness of 0.20 mm, a wound core was manufactured in the same manner as in Test Example 1, and a transformer with a capacity of 1 kVA was manufactured using the manufactured wound core. The manufactured wound core has the same configuration as that illustrated in FIG. Each of the four bent portions of this wound core was compressed at the pressure shown in Table 3 using a wooden compressing means. The lamination factor of the wound core used in the manufactured transformer was calculated based on JIS C 2550-5:2011. In addition, iron loss (no-load loss) and sound pressure were measured in the same manner as in Test Example 1 for the wound cores used in the manufactured transformers. Table 3 shows values ​​of compressive force, space factor, sound pressure and iron loss. Note that the average space factor A in Table 3 indicates the average space factor of the electromagnetic steel sheets at the four bent portions, and the average space factor B indicates the space factor of the electromagnetic steel sheets at the four side portions. Also, FIG. 6 shows the relationship between the average space factor A and the sound pressure. Inventive examples in Table 3 refer to examples to which the present disclosure is applied, and comparative examples refer to examples to which the present disclosure is not applied.
[0055]
[Table 3]

[0056]
　As shown in Table 3, when the average space factor A, which is the average space factor of the electromagnetic steel sheets in the four bent parts, is (B-4.0)% or more, the sound pressure decreases and the iron Reduced losses. Moreover, as shown in FIG. 6, when the space factor A was 96.0% or more, the sound pressure became smaller.
[0057]
　As described above, according to the present disclosure, it is possible to provide a wound core in which iron loss is reduced and noise is suppressed.
[0058]
　Although the preferred embodiments and examples of the present disclosure have been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field to which the present disclosure belongs can conceive of various modifications or modifications within the scope of the technical idea described in the claims. It is understood that these also naturally belong to the technical scope of the present disclosure.
[0059]
　The following additional remarks are disclosed regarding the above embodiments.
[0060]
　(Appendix 1)
　A laminated body in which a plurality of electromagnetic steel sheets are laminated in an annular shape when viewed from the side, and the
　laminated body includes a plurality of bent portions and a plurality of side portions positioned between the adjacent bent portions. and
　at least one of the plurality of bent portions has a higher space factor than the average space factor of the electromagnetic steel sheets in the plurality of side portions. A wound core, which is a product moment bending portion.
[0061]
　(Appendix 2)
　When the average space factor (%) of the electromagnetic steel sheets in the plurality of side portions is B, the average space factor A of the electromagnetic steel sheets in the plurality of bent portions is (B-4.0). % or more, the wound core according to Appendix 1.
[0062]
　(Appendix 3)
　The wound core according to Appendix 1 or Appendix 2, further comprising compressing means for compressing the plurality of electromagnetic steel sheets in the high space factor bent portion in a stacking direction of the electromagnetic steel sheets.
[0063]
　(Additional remark 4) The
　compressing means includes a
　first contact portion disposed on the outer peripheral side of the high space factor bending portion and in contact with the
　high space factor bending portion, and an inner circumference of the high space factor bending portion. a second contact portion that is arranged on the side and contacts the high space factor bending portion; and
　a connection portion that connects the first contact portion and the second contact portion,
　the first 3. The contact portion and the second contact portion according to appendix 3, wherein the contact portion and the second contact portion receive a restraining force from the connecting portion and compress the plurality of magnetic steel sheets in the high space factor bent portion in a stacking direction of the magnetic steel plates. Wound iron core.
[0064]
　(Appendix 5)
　The wound core according to Appendix 4, wherein the first contact portion and the second contact portion, or the connecting portion is formed of a non-magnetic material.
[0065]
　(Additional remark 6)
　It has the said bending part which opposes through the center of the said laminated body in the side view, and the said bending part which
　opposes is the said high space factor bending part, respectively, and the
　said compression means is a side view. The wound core according to appendix 3, further comprising a compression member that compresses the high space factor bent portions that face each other across the center of the laminate.
[0066]
　(Appendix 7)
　The compression member is a rod-shaped member that can be expanded and contracted, and is arranged on a straight line that connects the corners of the high space factor bent portions facing each other in the side view inside the laminate, 7. The wound core according to appendix 6, wherein the plurality of electromagnetic steel sheets in the high space factor bent portions facing each other in an elongated state are compressed in a stacking direction of the electromagnetic steel sheets.
[0067]
　(Appendix 8)
　The wound core according to Appendix 6 or Appendix 7, wherein the compression member is formed of a non-magnetic material.
[0068]
　(Appendix 9)
　The wound core according to any one of Appendices 1 to 8, wherein the high space factor bent portion is compressed with a pressure of 0.2 MPa or more and 4.0 MPa or less.
[0069]
　(Appendix 10)
　When the average space factor (%) of the electromagnetic steel sheets in the plurality of side portions is B, the space factor C of the electromagnetic steel sheets in the high space factor bending portion is B% or more (B+1 )% or less, the wound core according to any one of Appendixes 1 to 9.
[0070]
　(Appendix 11)
　The wound core according to any one of Appendices 1 to 10, wherein all of the bent portions are the high space factor bent portions.
[0071]
　(Appendix 12)
　The roll according to any one of Appendices 1 to 11, wherein the shape of the laminate when viewed from the side is an octagon having four sides and four bends. Iron core.
[0072]
　(Appendix 13)
　A laminated body in which a plurality of electromagnetic steel sheets are annularly laminated in a side view and has a plurality of bent portions and a plurality of side portions positioned between the adjacent bent portions, wherein the plurality of bent
　portions at least one of the bent portions is a high space factor bent portion in which the space factor of the electromagnetic steel sheets in the bent portion is equal to or higher than the average space factor of the electromagnetic steel sheets in the plurality of side portions. Iron core.
[0073]
(Appendix 14)
　When the average space factor (%) of the electromagnetic steel sheets in the plurality of side portions is B, the average space factor A of the electromagnetic steel sheets in the plurality of bent portions is (B-4.0). % or more, the wound core according to Appendix 13.
[0074]
(Appendix 15)
　The wound core according to Appendix 13 or Appendix 14, wherein the high space factor bent portion includes compression means for compressing the electromagnetic steel sheets in the stacking direction of the high space factor bent portion.
[0075]
(Supplementary Note 16) The
　compressing means includes
　contact portions that contact the high space factor bent portion on the outer peripheral side and the inner peripheral side of the high space factor bent portion, and the contact portion
　disposed on the outer peripheral side. and a connection portion that connects the portion and the contact portion disposed on the inner peripheral side, and the
　contact portion receives the biasing force of the connection portion and is moved in the lamination direction of the electromagnetic steel sheets. 16. The wound core according to appendix 15, wherein the bent portion is compressed.
[0076]
(Appendix 17)
　The wound core according to Appendix 16, wherein the contact portion or the connecting portion includes a non-magnetic member.
[0077]
(Appendix 18)
　The wound core according to appendix 15, wherein the compressing means includes a compressing member that compresses the high space factor bent portions that face each other across the center of the laminate in a side view.
[0078]
(Appendix 19)
　The wound core according to Appendix 18, wherein the compression member is a non-magnetic material.
[0079]
(Appendix 20)
　The wound core according to any one of Appendices 13 to 19, wherein the high space factor bent portion is compressed with a pressure of 0.2 MPa or more and 4.0 MPa or less.
[0080]
(Appendix 21)
　When the average space factor (%) of the electromagnetic steel sheets in the plurality of side portions is B, the space factor C of the electromagnetic steel sheets in the high space factor bending portion is B% or more (B + 1 )% or less, the wound core according to any one of appendices 13 to 20.
[0081]
(Appendix 22)
　The wound core according to any one of Appendices 13 to 21, wherein the laminate has an octagonal shape when viewed from the side.
[0082]
　The disclosure of Japanese Patent Application No. 2019-164446 filed on September 10, 2019 is incorporated herein by reference in its entirety.
　All publications, patent applications and technical standards mentioned herein are to the same extent as if each individual publication, patent application and technical standard were specifically and individually noted to be incorporated by reference. incorporated herein by reference.
The scope of the claims
[Claim 1]
　A laminate in which a plurality of electromagnetic steel sheets are annularly laminated in a side view, the laminate having
　a plurality of bent portions and a plurality of side portions positioned between the adjacent bent portions, a
　plurality of At least one of the bent portions of the bent portion is a high space factor bent portion in which the space factor of the electromagnetic steel sheet in the bent portion is higher than the average space factor of the electromagnetic steel sheets in the plurality of side portions is a wound iron core.
[Claim 2]
　When the average space factor (%) of the electromagnetic steel sheets in the plurality of side portions is B, the average space factor A of the electromagnetic steel sheets in the plurality of bent portions is (B-4.0)% or more. , The wound core according to claim 1.
[Claim 3]
　The wound core according to claim 1 or 2, further comprising compressing means for compressing the plurality of electromagnetic steel sheets in the high space factor bent portion in a stacking direction of the electromagnetic steel sheets.
[Claim 4]
　The compressing means is arranged on the outer peripheral side of the high space factor bent portion, 　and is arranged on the inner peripheral side of the high space factor bent portion
　and the first contact portion that contacts the high space factor bent portion.
, a second contact portion that contacts the high space factor bent portion; and
　a connection portion that connects the first contact portion and the second contact portion,
　wherein the first contact portion and 4 . The wound core according to claim 3 , wherein the second contact portion receives a restraining force from the connecting portion and compresses the plurality of electromagnetic steel sheets in the high space factor bending portion in a stacking direction of the electromagnetic steel sheets.
[Claim 5]
　The wound core according to claim 4, wherein the first contact portion and the second contact portion or the connecting portion are formed of a non-magnetic material.
[Claim 6]
　It has the bent portions that face each other through the center of the laminate in a side view, and the
　opposed bent portions are the high space factor bent portions, and the
　compressing means is a portion of the laminate in a side view. The wound core according to claim 3, comprising a compression member that compresses the high space factor bent portions facing each other across the center.
[Claim 7]
　The compression member is a rod-shaped member that can be expanded and contracted, and is arranged on a straight line that connects the corners of the high space factor bent portions that face each other inside the laminate and in a side view, and faces each other in a stretched state. The wound core according to claim 6, wherein the plurality of electromagnetic steel sheets in the high space factor bending portion are compressed in the stacking direction of the electromagnetic steel sheets.
[Claim 8]
　The wound core according to claim 6 or 7, wherein said compression member is formed of a non-magnetic material.
[Claim 9]
　The wound core according to any one of claims 1 to 8, wherein the high space factor bent portion is compressed with a pressure of 0.2 MPa or more and 4.0 MPa or less.
[Claim 10]
　When the average space factor (%) of the electromagnetic steel sheets in the plurality of side portions is B, the space factor C of the electromagnetic steel sheets in the high space factor bending portion is B% or more and (B+1)% or less. The wound core according to any one of claims 1 to 9.
[Claim 11]
　The wound core according to any one of claims 1 to 10, wherein all said bending portions are said high space factor bending portions.
[Claim 12]
　The wound core according to any one of claims 1 to 11, wherein the shape of the laminate when viewed from the side is an octagon having four sides and four bends.