Technical field
[0001]
The present invention is a wound core, and a method of manufacturing the same.
The present application, on January 10, 2017, claiming priority based on Japanese Patent Application No. 2017-001829, filed in Japan, the contents of which are incorporated here.
BACKGROUND
[0002]
Wound core is trans, reactors, has been widely used as a magnetic core such as noise filter. Conventionally, reduction of iron loss caused by the iron core in view of high efficiency has become an important issue, considering the low iron loss have been made from various viewpoints.
[0003]
　One of the method for manufacturing the wound core, for example, after winding the steel sheet into a tubular shape, and pressed to the corner portions constant curvature, after forming the substantially rectangular, stress relief and shape retention by annealing how to do is widely known. In this production method is different from the curvature radius of the corner portion depending on the size of the wound core, the radius of curvature has a substantially 4mm or more relatively large gently curved surface.
[0004]
　Method Another method for manufacturing a wound core, previously bent portions to be a corner portion of the wound core of an electromagnetic steel sheet to the bending processed by superimposing an electromagnetic steel sheet, wound cores by laminating electromagnetic steel plates There has been studied.
　According to this manufacturing method, the pressing step is not required, also referred to as the held shape since the bent magnetic steel sheets, the shape retention by the annealing step is not an essential step, it is easy to manufacture there is a merit. In this method, since the bending of electromagnetic steel sheets, a relatively small bending region of the curvature radius of 3mm or less to the working portion is formed.
[0005]
　As bending wound core manufactured by a manufacturing method including a process, for example, Patent Document 1, a plurality of magnetic steel plates of different lengths which are bent annularly formed juxtaposed against the outer circumferential direction, of each of the magnetic steel plates opposing end surfaces, predetermined dimensions by evenly displaced throughout the stacking direction, the structure of the wound iron core joint portion is made stepwise is disclosed.
CITATION
Patent Document
[0006]
Patent Document 1: Japanese Mian Registration No. 3081863
Summary of the Invention
Problems that the Invention is to Solve
[0007]
　The present invention has been made in view of the above circumstances, while having a bent region, and an object thereof is to provide iron loss wound core which is suppressed, and a manufacturing method thereof.
Means for Solving the Problems
[0008]
　Overview of the present invention is as follows.
(1) the first aspect of the present invention, a plurality of bent bodies coating containing phosphorus on the surface is formed from a grain oriented electrical steel sheet is formed, which is constituted by laminating to its thickness direction a wound core, the bending member includes a flat portion is formed in a rectangular shape by each having four and a corner portion adjacent to the flat portion, the corner portion, as viewed from the side, the bending angle of the total has a bending region is substantially 90 °, viewed from the side, the number of deformation twins present in the bent region, the thickness direction of the center line five or less per length of 1mm in the bent region There, elution of phosphorus from the corner portion when boiled in water for 30 minutes, the surface area 1m of the corner portion 2 or less per 6.0 mg.
In it has been wound core according to (2) above (1), the directional electromagnetic steel plates, steel plates local distortion is applied to the surface, or it may be a steel plate having grooves formed on the surface.
(3) In has been wound core according to the above (1), Si content of the grain-oriented electrical steel sheet may be from 2.0 to 5.0 mass%.
(4) In has been wound core according to the above (1), the bent region, the in a side view of the bending member, the bent member D and point E a point on the line La, which represents an interior surface of the, and, the bending point F and the point G on the line Lb representing the outer surface of the workpiece when defining as follows, the bending of the point on the line La which represents the inner surface D and the point E and separated by a line, wherein bending of the point on the line Lb representing the outer surface F and the point G and separated by a line, a straight line connecting the point G and the point D, and the region surrounded by the straight line connecting the point F and the point E it may be.
　
　in side view, the central point A of the curvature radius of the curved section included in the line La which represents the inner surface of the bending member, the outer surface of the bending member the obtained by extending the straight portion adjacent to the respective sides of the curved portion contained in the line Lb representing two imaginary lines Lb-elongation1, Lb-elongation2 line AB connecting the point of intersection B of, the bent body the point of intersection with the line representing the inner surface as the origin C,
　along the lines La which represents the inner surface of the bending member from the origin C, and a point at a distance m, represented in one direction by the following formula (1) and point D,
　along the lines La which represents the inner surface of the bending member from the origin C, and a point distant by the distance m in the other direction to the point E,
　contained in the line Lb representing the outer surface of the bending member among the straight portion to be A straight portion opposed to the point D, and point G the intersection of the imaginary line passing through and the point D drawn perpendicular to the straight portion facing the point D,
　the line representing the outer surface of the bending member among the straight portion included in Lb, and a straight portion opposed to the point E, a point F of intersection between an imaginary line and drawn perpendicular to the straight portion facing the point E passing through the point E to.
　Equation (1): m = r × ([pi / 4)
(in the formula (1), m represents the distance from the origin C, r denotes the distance from the center point A to the origin C (radius of curvature)).
(5) The second aspect of the present invention is a method of manufacturing a wound core described in the above (1), a preparation step of preparing a plurality of oriented electrical steel sheet having a coating containing phosphorus on the surface If, for each corner forming region preassigned to the plurality of the grain oriented electrical steel sheets, by bending in a state in which the temperature was set to 0.99 ° C. or higher 500 ° C. or less of the corner portion forming region, substantially in a side view and a step bend forming a plurality of bending which is a rectangular shape, a plurality of the bent body, the lamination step of laminating the plate thickness direction.
Effect of the invention
[0009]
　According to the present invention, while having a bending region, iron loss wound core which is suppressed, and a manufacturing method thereof can be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010]
FIG. 1 is a perspective view of a wound core according to a first embodiment of the present invention.
FIG. 2 is a side view of a wound core according to the embodiment.
It is a side view showing a first modified example of FIG. 3 wound core.
It is a side view showing a second modification of FIG. 4 wound core.
FIG. 5 is an enlarged side view of a vicinity of the corner portions of the wound core according to a first embodiment of the present invention.
6 is an enlarged side view of a vicinity of the corner portions of the wound core according to the first modified example.
7 is an enlarged side view of a vicinity of the corner portions of the wound core according to a second modification.
8 is an explanatory diagram relating to the bending region.
9 is a side view of the bending of the wound core according to a first embodiment of the present invention.
It is a side view showing a modified example of FIG. 10 bending member.
It is a side view showing another modified example of FIG. 11 bent body.
Is a side view showing an example of a sampling position of the sample in FIG. 12 wound core.
13 is an explanatory view of a bending process in the method for manufacturing a wound core according to a second embodiment of the present invention.
14 is a schematic diagram showing the dimensions of the wound core prepared in Example.
[15] The side surface of the bending region of the bent member constituting the conventional wound core is an enlarged photograph taken with an optical microscope.
DESCRIPTION OF THE INVENTION
[0011]
(Causes and mechanism of inhibition of iron loss)
　the present inventors have found that in the bending region formed upon bending the oriented electrical steel sheet, to obtain a finding that the iron loss is increased. Figure 15 is a bent member is formed from the directional electromagnetic steel plates constituting the conventional wound core side of the bending region (hereinafter, simply bending referred to as workpiece) in the enlarged photographs taken with an optical microscope is there.
　As shown in the example of the figure 15, in the bending region of the bent member, streaky deformation twins 7 (deformation twin) was observed from the surface of the steel sheet toward the interior. Incidentally, it was confirmed by analysis assessed using the crystal orientation analysis software and scanning electron microscopy (EBSD) variations are twins. Oriented electrical steel sheet, the orientation of the crystal grains in the steel sheet {110} <001> orientation is a steel plate which has highly integrated (hereinafter, sometimes referred to Goss orientation), deformation twins portions crystal orientation There because different from the Goss orientation, is assumed to be the cause of the iron loss. Also even if the annealing of about 750 ° C. After wound core formed, it was not possible to eliminate the deformation twins generated during bending.
　The present inventors have found that bending results deformed advanced intensive studies of inhibition of the twins during processing, clear that the deformation twins is inhibited by performing a bending while heating the oriented electrical steel sheet It became. Such the effect on the action to achieve the is also unclear part, by the working portion becomes high, dislocations introduced by plastic deformation tends to exercise not only to suppress the occurrence of deformation twins, since the deformation twins generated is less likely to grow, it is estimated that does not extend into streaks. Result, deformation twins area fraction of the total steel sheet is reduced, it is estimated that influence on iron loss is reduced.
　Furthermore, as the bending temperature during processing of oriented electrical steel sheet with high temperature, but tends to generate deformation twins is inhibited was observed, even if the occurrence of deformation twins is inhibited when a high temperature iron loss of the wound core there was a case of not suppressed. The cause is also unknown parts, cracking of the coating occurs in the bending region by processing at high temperatures, sticking of the mother steel plates exposed at the bent region that occurs is estimated to be the cause.
　The present inventors have found that these findings, bent by adjusting the temperature of the grain-oriented electrical steel sheet to 0.99 ° C. or higher 500 ° C. or less at the time of processing, the deformation and twinning of generation, cracking of the coating is suppressed together the clear, while having a bending region, iron loss and completed the winding core of the present invention was inhibited.
[0012]
　Hereinafter, the wound core according to the present invention made based on the above findings, and, in turn be described in detail a manufacturing method thereof.
　Incidentally, as used herein, it identifies the shape and geometric conditions and the degree thereof, such as "parallel", "perpendicular", for values such terms and length and angle such as "identical" strict meaning without being bound, and interpreting including range that can expect a similar function. Further, in the present invention, is approximately 90 °, is intended to permit an error of ± 3 °, it means a range of 87 ° ~ 93 °.
[0013]
(First Embodiment)
　FIG. 1 is a perspective view schematically showing the wound core 10 according to the first embodiment of the present invention. Figure 2 is a side view of the wound core 10 according to the embodiment.
　Note that the side view in the present invention refers to viewing in the widthwise direction of the elongated oriented electrical steel sheet which constitutes the wound core (Y-axis direction in FIG. 1), the side view is viewed by the side view that the shape is a representation Figure (Y-axis direction in view of FIG. 1). Further, the thickness direction, a thickness direction of a grain-oriented electrical steel sheet, in a state of being formed into a rectangular wound core means a direction perpendicular to the peripheral surface of the wound core.
[0014]
　Wound core 10 according to this embodiment, the processed body 1 a plurality of bending the coating formed from the formed direction electrical steel sheet containing phosphorus on the surface, formed by laminating in the thickness direction. Namely, the wound core 10, Figure 1, as shown in FIG. 2, has a substantially rectangular lamination structure of a plurality of bent bodies 1. The wound core 10 may be used as it is as a wound core, but may be fixed to wound cores using a fastener such as a known binding band as needed.
[0015]
　As shown in FIGS. 1 and 2, each of the bent body 1, four flat portions 4 and along the circumferential direction and four corners 3 are formed in a rectangular shape by an alternating series. Angle between two planar portions 4 adjacent to each corner portion 3, is approximately 90 °.
[0016]
　As shown in FIG. 2, the wound core 10 according to the present embodiment, each of the corner portions 3 of the bending element 1 is, in a side view, the two bent regions 5 Total is approximately 90 ° bend angle a. Bending region 5 is a region having a shape bent in a curved shape in a side view of the bending body 1 will be described later more specific definitions.
　Each bending member 1 of the corner portion 3, so that the winding core 10A according to the first modified example shown in FIG. 3, may have a three bending region 5, also the second variant shown in FIG. 4 as wound core 10B of the example may have one bending area 5. That is, each of the corner portions 3 of the bending body 1, only it needs to have one or more bend regions 5.
[0017]
　Figure 5 is a side view enlarging a vicinity of the corner portion 3 in the wound core 10 according to the present embodiment.
　As shown in FIG. 5, one of the corners two bent region 5a, when having 5b is straight portion to the bent region 5a representing the flat portion 4a of the bending member 10 (curved portion) is continuously and, the linear portion to its destination, bending area 5b (curved portion), and a flat portion 4b are continuous.
[0018]
　In wound core 10 according to the present embodiment, the region of 'the line B-B' line A-A up in FIG. 5 are the corner portion 3. Point A is the end point of the flat portion 4a side of the innermost positioned flexural bending region 5a of the cutting body 1a of the winding core 10, the point A 'is perpendicular to the plate surface of the street bent body 1a point A the direction of the straight line is the intersection between the outermost surface of the wound core 10. Similarly point B is the end point of the flat portion 4b side in the most disposed inside the bending member 1a of the bending region 5b of the winding core 10, the point B 'is the plate surface of the street bent body 1a point B and vertical straight line is the intersection between the outermost surface of the wound core 10. 5, two planar portions 4a adjacent via the corner portion 3, 4b angle formed is theta, are the theta is substantially 90 ° in the present invention. Bending region 5a, will be described later bending angle φ of 5b, φ1 + φ2 5 is approximately 90 °.
[0019]
　Then, one corner portion 3 will be described the case where the bending region 5 three has. Figure 6 is a side view enlarging a vicinity of the corner portion 3 in the wound core 10A according to the first modification example shown in FIG. Similar to FIG. 5 also in FIG. 6, the region of 'the line B-B' line A-A until it is the corner portion 3. 6, the point A is the end point of the flat portion 4a side of the nearest bend region 5a to the flat portion 4a, the point B is the end point of the flat portion 4b side of the nearest bend region 5b in a planar portion 4b. If the bending region 5 is three or more, straight portion exists between each bending region. Any of the flat portion is flat portion 4a, for either configure 4b, be determined in consideration of the two planar portions 4a adjacent via the corner portion 3, is an angle θ of 4b is approximately 90 ° better, thereby bending region 5 adjacent to the flat portion 4 is determined. Note that in the example of FIG. 6, φ1 + φ2 + φ3 becomes a substantially 90 °, generally the corner portion 3 when having n bending region 5, φ1 + φ2 + ··· + φn is substantially 90 °.
[0020]
　Then, one corner portion 3 will be described having one bending region 5. Figure 7 is a side view enlarging a vicinity of the corner portion 3 in the wound core 10B according to a second modification example shown in FIG. Similarly to FIG. 5 and 6 in FIG. 7, the region of 'the line B-B' line A-A until it is the corner portion 3. 7, point A is the end point of the flat portion 4a side of the bending region 5, the point B is the end point of the flat portion 4b side of the bent region 5. In the example of FIG. 7, .phi.1 is approximately 90 °.
[0021]
　In the present application, since the angle θ of the corner portion of the aforementioned is approximately 90 °, phi is approximately 90 ° or less. Deformation from the viewpoint of suppressing the iron loss by suppressing the occurrence of twins, phi is preferably at 60 ° or less, more preferably 45 ° or less. Therefore, one corner portion 3 preferably has two or more bending region 5. However it, shaping the four or more bending region 5 in one corner portion 3, since it is difficult on the production equipment design constraints, the number of bending area 5 at one corner portion is three or less It is preferred.
　As the wound core 10 according to the present embodiment shown in FIG. 5, one corner portion has two bending region 5a, when having 5b, be in terms of reducing iron loss .phi.1 = 45 ° and .phi.2 = 45 ° is preferred, for example, be a .phi.1 = 60 ° and .phi.2 = 30 °, may be .phi.1 = 30 ° and .phi.2 = 60 ° like.
　Further, as the wound core 10A according to the first modification shown in FIG. 6, one corner portion are three bending areas 5a, 5b, when having 5c, φ1 = 30 ° in terms of reducing iron loss, .phi.2 = it is preferable that the 30 ° and .phi.3 = 30 °.
　Furthermore, since it is preferable that bending angle are equal in terms of production efficiency, in a case where one corner portion has two bent region 5a, the 5b (FIG. 5), and .phi.1 = 45 ° and .phi.2 = 45 ° it is preferable, in the case (FIG. 6) in which one corner has three bending areas 5a, 5b, the 5c, from the viewpoint of reducing iron loss, for example, φ1 = 30 °, φ2 = 30 ° and .phi.3 = 30 ° it is preferable that the.
[0022]
　With reference to FIG. 8, it will be described in more detail bending region 5. Figure 8 is a diagram schematically showing an example of a bending region 5 of the bending body 1. The bending angle of the bending region 5, bent at the bending region 5 of the worked body 1 is meant the angle difference caused between the folding direction of the linear portion of the rear side and the front side of the straight portion. Specifically, the bending angle of the bending region 5 is extended in the bending region 5, the straight portion adjacent to the respective sides (point F and the point G) of the curved portion included in the line Lb representing the bending outer surface of the worked body 1 two imaginary line Lb-elongation1, Lb-elongation2 obtained is represented as an angle φ of supplementary angles formed by.
　Bending angles of the bending region 5 is about 90 ° or less, and the sum of the bending angle of all the bending region 5 present on one corner portion 3 is substantially 90 °.
[0023]
　The bending region 5 in the present application, the bending side view of the worked body 1, bending body point D and a point E on line La which represents the first inner surface and a point on the line Lb representing the bending outer surface of the worked body 1 the F and point G when defining as follows, bent body delimited line 1 on line La which represents the inner surface at the points D and E, a point on the line Lb representing the outer surface of the bending member F DOO points separated by a line with a G, a straight line connecting said point G and the point D, and shows a region surrounded by the straight line connecting said point F and the point E.
[0024]
　Here, the point D, point E, the point F and the point G is defined as follows.
　In side view, a straight line adjacent to each opposite sides of curved portion contained in the line Lb representing the center point A of the curvature radius of the curved section included in the line La, which represents an interior surface of the bending member 1, the outer surface of the bent body part the resulting by extending two imaginary lines Lb-elongation1, Lb-elongation2 line AB connecting the point of intersection B of a point of intersection with the line representing the inner surface of the bending member 1 as the origin C,
　from the origin C bending along a line La, which represents an interior surface of the workpiece 1, one of the distance m apart point D to point represented by the following formula (1) in the direction,
　a line representing the inner surface of the workpiece bending from the origin C along la, the distance is m apart point E a point in the other direction,
　of the straight portion included in the line Lb representing the outer surface of the bending member, and the straight portion opposed to the point D, the straight opposite the point D The intersection of the imaginary line passing through and the point D drawn perpendicular to the portion to a point G,
　of the straight portion included in the line Lb representing the outer surface of the bending member, the linear portion opposed to the point E When, the intersection of the virtual line passing through the vertically drawn and the point E to the linear portion facing to the point E and the point F.
　Equation (1): m = r × ([pi / 4)
(in the formula (1), m represents the distance from the origin C, r denotes the distance from the center point A to the origin C (radius of curvature)).
[0025]
　That, r is shows the radius of curvature when considered curve near the origin C arc, in the present application, represents an inner surface radius of curvature in the side view of the bending region 5. As the radius of curvature r is less bending of the curved section of the bending region 5 is abrupt bend of the curve portion of the bending region 5 the larger the radius of curvature r becomes gentle.
　In the present application, even if the curvature radius r is formed following the bending region 5 3 mm by bending, occurrence of deformation twins in the bending region 5, is suppressed cracking of the coating containing phosphorus because you are, low iron loss of the wound core is obtained.
[0026]
　9, the bent body 1 of the wound core 10 according to this embodiment is a diagram schematically illustrating. As shown in FIG. 9, the bending member 1, which has been processed folded oriented electrical steel sheet has a four corner portions 3, and four flat portions 4, thereby, one oriented electrical steel sheet to form a substantially rectangular ring in a side view of the. More specifically, bent body 1, one plane portion 4 includes a joint part 6 is an end in the longitudinal direction (the gap), the other three flat portion 4 is a structure that does not include the joint 6 ing.
　However, the wound core 10, a side view is may have a laminated structure of substantially rectangular shape as a whole. Therefore, as a modified example, as shown in FIG. 10, two planar portions 4 includes a joint portion 6, the other two planar portions 4 may be used bent body 1A does not include the joint 6. In this case, configuring the bending member is two oriented electrical steel sheet.
　Also, as a further variation in the case of constituting the workpiece bending two sheets of grain-oriented electrical steel sheet, as shown in FIG. 11, a plane portion 4 comprises two joints 6, the other three planes part 4 may be used bent body 1B does not include the joint 6. That is, the bending member 1B has a grain-oriented electrical steel sheet, which corresponds to three sides of a substantially rectangular, straight corresponds to one side rest (side view is straight) and is configured by combining a directional magnetic steel sheet. When configuring in this manner the two or more oriented electrical steel sheet is bent member, and bending of the steel plate, (the side view on a straight line) straight may be combined with the steel plate.
　To avoid a gap between two layers adjacent to the time the wound core manufacturing any case, the bending of the adjacent two layers, an outer peripheral length of the flat portion 4 of the bending member is arranged inside, outside position of the length and the bending region of the steel sheet as the inner circumferential length of the flat portion 4 of the bent member is positioned is equal is adjusted.
[0027]
(Directional configuration of an electromagnetic steel sheet)
　oriented electrical steel sheet includes at least a base steel is one having a coating containing phosphorus base steel surface, within a range not to impair the effects of the present invention, further optionally it may have other layers. Other layers, for example, and the base steel, such as glass film which is provided between the film containing the phosphorus and the like. The following describes the structure of the grain-oriented electrical steel sheet.
[0028]
(1) base steel
　in the grain-oriented electrical steel sheet used in the wound core 10 according to the present embodiment, the base steel sheet, steel sheet orientation of the crystal grains of the mother steel sheet is highly integrated in the {110} <001> orientation , and the having excellent magnetic properties in the rolling direction.
　Base steel in the present invention is not particularly limited, from known materials used as grain-oriented electrical steel sheet, can be appropriately selected. Hereinafter, a description will be given of an example of a preferred base steel, the base steel sheet in the present invention is not intended to be limited to the following.
[0029]
　Chemical composition of the base steel sheet is not particularly limited, for example, by mass%, Si: 0.8% ~ 7 %, C: higher than 0% 0.085% or less, acid soluble Al: 0 % ~ 0.065%, N: 0 % ~ 0.012%, Mn: 0% ~ 1%, Cr: 0% ~ 0.3%, Cu: 0% ~ 0.4%, P: 0% ~ 0.5%, Sn: 0% ~ 0.3%, Sb: 0% ~ 0.3%, Ni: 0% ~ 1%, S: 0% ~ 0.015%, Se: 0% ~ 0. containing 015%, and preferably the balance being Fe and impurities. Chemical composition of the base steel is a preferred chemical composition in order to control the Goss texture was integrated crystal orientation {110} in the <001> orientation. Of elements in the base steel, Si and C is a basic element, acid-soluble Al, N, Mn, Cr, Cu, P, Sn, Sb, Ni, S, and Se are a selective element. These optional elements are not necessary to limit the lower limit value so may be contained according to the purpose, it may not substantially contain. These selection elements be contained as unavoidable impurities, the effect of the present invention is not impaired. Mother steel sheet, the remainder of the basic elements and selection elements consisting of Fe and unavoidable impurities.
　However, Si content of the base steel sheet, if 2.0% or more by mass%, preferably for classical eddy current loss of the product is suppressed. Si content of the base steel sheet is more preferably 3.0% or more.
　Further, Si content of the base steel sheet is less than or equal 5.0% by mass% is preferable because since hardly occurs cracking of the steel sheet in the hot rolling step and cold rolling. Si content of the base steel sheet is more preferably at most 4.5%.
　In the present application, the term "inevitable impurities", when manufacturing the base steel industrially, means inevitably mixed elemental ore as a raw material, scrap or from the manufacturing environment and the like.
　Further, the grain-oriented electrical steel sheet it is common to go through a purification annealing at the secondary recrystallization. Emissions to the outside of the system of the inhibitor-forming element occurs in the purification annealing. In particular N, decrease in concentration pronounced for S, it becomes 50ppm or less. If ordinary purification annealing conditions, 9 ppm or less, more 6ppm or less, if sufficiently performed purification annealing, reaches a degree that can not be detected (1 ppm or less) in the general analysis.
　Chemical composition of base steel may be measured by general analytical methods of steel. For example, the chemical components of the base steel can be measured by using ICP-AES (Inductively Coupled Plasma- Atomic Emission Spectrometry). Specifically, for example, it acquires the test piece 35mm angle from the central position of the base steel sheet after coating removal by Shimadzu ICPS-8100, etc. (measuring device), with conditions based on the previously prepared calibration curve It can be identified by measuring. Incidentally, C and S are combustion - infrared absorption method using, N is the inert gas fusion - can be measured with a thermal conductivity method.
　The chemical components of the base steel is a component of the analysis of the components of the steel sheet obtained by removing the coating such as containing glass film and phosphorus described later by a method described later, from the grain-oriented electrical steel sheet as a base steel sheet.
[0030]
　Method of manufacturing a base steel is not particularly limited, the manufacturing method of the conventional oriented electrical steel sheet can be appropriately selected. After Preferred specific production method, for example, a 0.04 to 0.1 wt% of C, others subjected to a slab is heated to above 1000 ° C. hot rolling having a chemical composition of the base steel performs hot-rolled sheet annealing as needed, then, once or a cold rolled steel sheet by twice or more cold rolling sandwiching the intermediate annealing, the cold-rolled steel sheet, for example, wet hydrogen - in an inert gas atmosphere 700 It was heated to ~ 900 ° C. decarburization annealing, further nitriding annealing as required, and a method of finish annealing at about 1000 ° C..
　The thickness of the base steel is not particularly limited as long e.g. 0.1mm or 0.5mm or less, or may be 0.15mm or 0.40mm or less.
　Moreover, directional magnetic steel sheet, local distortion imparting to the surface, or by forming grooves on the surface, it is preferable to use a steel sheet domain is subdivided. By using these steel plates, it is possible to further suppress the iron loss.
[0031]
(2) coating contains phosphorus
　oriented electrical steel sheet, in order to impart predominantly insulation, with a coating containing phosphorus. Coating containing the phosphorus are those provided on the outermost surface of the grain-oriented electrical steel sheet, provided on the respective film when having a glass film or an oxide film oriented electrical steel sheet will be described later.
　Coating containing phosphorus can be appropriately selected from conventionally known ones. The coating containing phosphorus, preferably phosphate-based coating, in particular, as a main component one or more of aluminum phosphate and magnesium phosphate and further, one or more of chromium and silicon oxide as a secondary component it is preferably a coating containing. According to phosphate-based film, while securing the insulating property of the steel sheet is also excellent in low iron loss giving tension to the steel sheet.
　Method of forming a film containing phosphorus is not particularly limited, it can be appropriately selected from known methods. For example, after a coating solution prepared by dissolving a coating composition was coated on the base steel sheet, a method of baking is preferable. Hereinafter will be described the preferred embodiment, the method of forming the film containing the phosphorus is not limited thereto.
[0032]
　Colloidal silica 4-16% by weight, aluminum phosphate 3-24% by weight (calculated as aluminum biphosphate), 0.2-4 one or more of chromic acid anhydride and dichromate in total preparing a coating solution containing .5% by weight. Then, the coating solution, glass film formed on the base steel or base steel or the like is coated on other film, baking at about 350 ° C. or higher. Then, by heat treatment at 800 ° C. ~ 900 ° C., it is possible to form a film containing phosphorus. Thus film thus formed has an insulating, it is possible to impart tension to the steel sheet, it is possible to improve the iron loss and magnetostriction property.
[0033]
　Is not particularly limited, the thickness of the coating containing the phosphorus is preferably 0.5μm or more 3μm or less from the viewpoint of ensuring insulation.
[0034]
(3) Other coatings
　are oriented electrical steel sheet, and base steel, other coatings containing phosphorus is formed on the outermost surface, further have another coating without impairing the effect of the present invention good. Such other coatings, such as glass coating formed on the base steel sheet and the like. Oriented electrical steel sheet preferably has a glass film from the viewpoint of improving the adhesion of the coating containing the phosphorus. The glass film, for example, forsterite (Mg 2 SiO 4 ), spinel (MgAl 2 O 4 ), and cordierite (Mg 2 Al 4 Si 5 O 16 having a) one or more oxides selected from coating and the like.
　Method of forming a glass film is not particularly limited, it can be appropriately selected from known methods. For example, in the above embodiment of the method of the base steel, the cold-rolled steel sheet magnesia (MgO) and alumina (Al 2 O 3 after the application of the annealing separator containing one or more selected from), Incidentally, the annealing separating agent also has the effect of suppressing the sticking of steel sheets during finish annealing. For example, when the application was conducted to finish-annealing the annealing separator containing said magnesia reacts with the silica contained in the base steel, forsterite (Mg 2 SiO 4 glass film containing)
[0035]
　The thickness of the glass film is not particularly limited, it is preferable from the viewpoint of the adhesion to the coating film containing phosphorus is 0.5μm or more 3μm or less.
[0036]
　The thickness of the grain-oriented electrical steel sheet is not particularly limited, but those may be appropriately selected in accordance with the application etc., is usually within the range of 0.15 mm ~ 0.35 mm, preferably 0.18 mm ~ 0 it is in the range of .23mm.
[0037]
(Bent portion of the characteristic)
　in the wound core 10 according to the present embodiment, in a side view, the number of deformation twins present in the bending region 5, the length per 1mm plate thickness direction of the center line in the bending region 5 5 this is less than or equal to.
　In other words, "one of the wound core 10 bending workpiece 1, included in one of the corner portions 3, all the bending region 5" the length of the plate thickness direction of the center line in the L Total and "N(mm), Total case of the (present), N Total / L Total is the value of (lines / mm) of 5 or less.
　The number of deformation twins present in the bending region 5 is preferably bent region 5 in which less than four lengths per 1mm plate thickness direction of the center line, and more preferably not more than three.
[0038]
　Further, in the wound core 10 according to the present embodiment, the elution amount of phosphorus from the corner portion 3 in the case of boiled in water for 30 minutes, the surface area 1m corner portion 3 2 or less per 6.0 mg.
　In other words, "one of the wound core 10 bending worked body 1, one corner portion 3" elution of phosphorus from P Elution and "S(mg), a (m 2 when a), P Elution / S a (mg / m 2 value of) is 6.0 or less.
　Elution of phosphorus from the corner portion 3 in the case where boiled for 30 minutes in water, the surface area 1m corners 3 2 is preferably not more than per 5 mg, and more preferably 4mg less.
[0039]
　Hereinafter, the elution amount of deformation twin number of crystals and phosphorus will be described in detail.
[0040]
(1) Modification number of twinning
　number of deformation twins present in the bending region 5 in a side view, the cross section of the bending region 5 taken using an optical microscope, streaky deformation twins toward the inside from the surface of the steel sheet 7 number of it Kazoeagere. As seen in the example of FIG. 15, the deformation twins are formed on the winding core outer circumferential surface and wound cores in a peripheral surface of the steel sheet. In the present application, the sum deformation twins formed on the outer circumferential surface, the deformation twins formed on the inner peripheral surface. It deformation is twinning can be confirmed by analysis assessed using a scanning electron microscope the crystal orientation analysis software (EBSD).
[0041]
　Here, how to create the sample for cross-section observation of the bending region 5, the wound core 10 according to the present embodiment will be described as an example.
　Samples for cross-section observation of the bending region 5, as shown in FIG. 12, among the plurality of bent body 1 which constitutes the winding iron wire 10, taken from the corner portion 3 corresponding to each other (regions shown in FIG. A) . From this area A, by using a shearing machine, taken encompassing samples with the bending region 5. At this time, clearance from shearing blades is set to approximately 0.1 ~ 2 mm, bending area 5 Nisen section is sheared so as not to cross. Further, since it is difficult to shear the bending body 1 superimposed at a time, to shear one by one.
　Then, with the superposed member sheared one by one, to fill up one side of the plate width in epoxy resin, polishing the embedded surface. In polishing, # 220 from abrasive paper # 80 particle size which is in the SiC abrasive paper JIS R 6010, # 600, # 1000, after changing to # 1500, mirror conducted 6 [mu] m, 3 [mu] m, the diamond polishing of 1μm finish.
　For finally corrode the tissue, 3% soaked 20 seconds weak solution was added respectively 2-3 drops of picric acid and hydrochloric acid to nital, by corroding the tissue, and the sample for cross-section observation of the bending region 5 to.
[0042]
　Further, the length of the plate thickness direction of the center line of the directional electromagnetic steel plates, the length of the curve KJ in Figure 8, is specifically determined as follows. And the straight line AB which is as hereinbefore defined, and a point H to the point of intersection of the line representing the outer oriented electrical steel sheet, the midpoint between the point H and the above-mentioned origin C and the point I. In this case the distance from the center point A to point I (radius of curvature) 'and, from the following equation (2), m' r is calculated. The length of the thickness direction of the center line of the time-oriented electrical steel sheet becomes '2 times (2m' m). Incidentally, the point K is the midpoint of the line segment EF, the point J is the midpoint of a line segment GD.
　Equation (2): m '= r ' × (π / 4)
(In the formula (2), m 'denotes the length from the point I to point K and point J, r' is the point from the central point A I distance to represent a (radius of curvature)).
　A sample collected had, as mentioned above, since those members are sheared one by one is superposed, comprising a plurality of bent regions 5. Therefore, the total length of the center line of all the bending region 5 in a sample, based on the number of deformation twins present in all the bending region 5 in a sample, the length of 1mm of the thickness direction of the center line in the bend region 5 per can determine the number of deformation twins contained in the bending region 5.
[0043]
(2) dissolution of phosphorus
　to cracking of the coating is present in the bending region 5, phosphorus is eluted from the cracked portion when boiled in water. Accordingly, in the present application, in the case where boiled 30 minutes in water, the surface area 1m corner 2 elution of phosphorus from the corner portion 3 of the per, the occurrence of sticking of steel sheets in the bending region 5 ease of used as an indicator.
[0044]
　Here, the sample creating method for measuring the elution amount of phosphorus from the corner portion 3, the wound core 10 according to the present embodiment will be described as an example.
　Samples for measuring the elution amount of phosphorus from the corner portion 3, as shown in FIG. 12, among the plurality of bent body 1 which constitutes the winding iron wire 10, shown in the corner portion 3 (in the figure correspond to each other regions B1), and it is taken from the plane portion 4 (areas shown in Figure B2) corresponding to each other. From region B1, using a shearing machine, taken a corner portion 3, a sample containing a portion of the flat portions 4, 4 adjacent to the corner portion 3. From regions B2, using shearing machine, taking samples consisting of only the flat plate portion. At this time, the area of the flat portion 4 of the samples taken from the area B1, the shear as the area of the flat portion 4 of the sample taken from the region B2 are the same conduct. Area of the flat plate portion is not particularly limited, for example, appropriately set the area of the single sample taken from the region B2 to the width 30 mm × length 280mm like. In any collection, clearance from shearing blades is set to approximately 0.1 ~ 2 mm, bending area 5 Nisen section is sheared so as not to cross. Further, since it is difficult to shear the bending body 1 superimposed at a time, to shear one by one.
　Then, the samples taken from the area B1 and the region B2 Prefecture, respectively poured into water in the same amount, after boiling at about 100 ° C. 30 minutes, and eluted in water by a molybdenum blue (ascorbic acid reduction) absorption photometry measuring the phosphorus as phosphate ions. The elution of phosphorus from the sample taken from the area B1 P B1 , the amount of elution of phosphorus from a sample taken from the region B2 P B2 and, P B1 -P B2 by calculating, from the corner portion 3 elution of phosphorus is determined in.
　As described above, the samples for a set of members taken from a plurality of bent bodies 1, the sum of the surface area of each member (corner portion 3 of the bending element 1), P B1 -P B2 is calculated by was based on the amount of elution of phosphorus, the surface area 1m corners 2 per can obtain the dissolution of phosphorus from the corner portion 3 in the case where boiled for 30 minutes in water.
　One of the surface area of the corner portion of one bent body, calculated from (bending the long side length of the thickness direction of the center line of the workpiece 1) × (width of the bent body 1) of × 2 formula can do.
[0045]
　To measure the amount of elution of phosphorus from the corner portion 3, of the samples taken from the region B1, it is conceivable to a sample by shearing the member containing only the corner portion, in which case, the bent portion There is a possibility that portions close to is sheared, there is a possibility that accurate measurement results can not be obtained, and with taking a respective sample from the region B1 and the region B2 as described above in the present application.
[0046]
　The present inventors, as a result of measuring the elution amount of phosphorus is variously changing the size of the sample cut out by shearing, the influence of elution of phosphorus from the side surface of the sample (cut surface) is extremely small, of the According to the method, it if is the same grain-oriented electrical steel sheet surface layer of an area coating containing phosphorus be different cutting area is present, the elution amount of phosphorus per unit area eluting therefrom are the same it has been confirmed.
[0047]
　Thus, the wound core 10 according to the present embodiment, deformation twins is less in the bending region 5, and, for elution of phosphorus in the corner portion 3 is small, core loss while having a bending region 5 inhibition It is. Therefore, the wound core 10 according to this embodiment, the transformer, a reactor, such as core such as noise filters, can be suitably used for any conventionally known applications.
[0048]
(Second Embodiment)
　Hereinafter, a method for manufacturing a wound core 10 described above.
　Method for manufacturing a wound core according to a second embodiment of the present invention includes a preparation step of preparing a plurality of oriented electrical steel sheet having a coating containing phosphorus on the surface, was previously assigned to a plurality of the grain oriented electrical steel sheet each corner portion forming region, by bending the temperature of the corner portion forming region in a state with 0.99 ° C. or higher 500 ° C. or less, and bending process for forming a plurality of bending which is a substantially rectangular shape in a side view comprises a plurality of bending members, a lamination step of laminating the plate thickness direction.
[0049]
　According to the above manufacturing method, it is possible to produce a wound core of low iron loss while having a bending region 5. Hereinafter, a method of manufacturing a wound core will be described sequentially in detail.
[0050]
(Preparation step)
　First, a grain-oriented electrical steel sheet having a coating containing phosphorus on the surface. Oriented electrical steel sheet may be produced, may be obtained commercially. Since the manufacturing method and the chemical composition of the grain-oriented electrical steel sheet is as described above, description thereof is omitted.
[0051]
(Bending step)
　Next, the bending processing the at least one portion after cutting the oriented electrical steel sheet to a desired length, each corner portion forming region pre-assigned to the grain-oriented electrical steel sheet as needed. Thus, a grain-oriented electrical steel sheet, continuously alternately and the flat portion and the corner portion, the angle between two planar portions adjacent to mold a bent body 1 is approximately 90 ° at each corner.
　Bending method of processing will be described with reference to the drawings. Figure 13 is a schematic diagram showing an example of a bending method in the manufacturing method of the wound core 10.
　Although construction of the machine is not particularly limited, for example, as shown in (A) of FIG. 13, normally, and a die 22 and a punch 24 for pressing further oriented electrical steel sheet and a like guide 23 for fixing the 21. Oriented electrical steel sheet 21 is conveyed in the direction of the conveying direction 25, it is fixed in a predetermined position (FIG. 13 (B)). Then by pressing with a predetermined force that is set in advance by the punch 24, the bending member having a bending region of the bent angle φ is obtained.
[0052]
　In the bending step, to control the temperature of the corner portion forming region 0.99 ° C. or higher 500 ° C. or less. By setting to the temperature range, deformation twin generation of crystals is suppressed, and, since even cracking of the coating containing phosphorus can be suppressed.
　Here, a portion for controlling the temperature may be any only site bend during bending. That is, the temperature of the flat plate portion is not particularly limited. However, as the grain-oriented electrical steel sheet, in the case of using a steel plate local distortion is applied to the surface to subdivide the magnetic domains, while controlling the temperature of the corner portion forming region 0.99 ° C. or higher 500 ° C. or less, it is preferable to control the temperature of the region excluding the corner portion forming region 300 ° C. or less.
　Temperature of the corner portion forming region, for example, a thermocouple was placed on the punch 24, the punch 24 is determined by measuring the temperature at the time of contact with the grain-oriented electrical steel sheet 21. Method of controlling the temperature of the corner portion forming region of the grain-oriented electrical steel sheet to below 500 ° C. 0.99 ° C. or higher is not particularly limited, for example, warming the member in contact with the grain-oriented electrical steel sheet such as a die 22, it can be controlled by an infrared heater or the like. If the die 22 heated, its temperature is should be appropriately set according to the thickness and the conveying time of the steel plate, as a guide, may be set to the temperature of the die 22 to 200 ℃ ~ 500 ℃.
[0053]
　Here, the temperature of the grain-oriented electrical steel sheet during bending is measured as follows. First, x-axis (the longitudinal direction of the grain-oriented electrical steel sheet) conveying direction 25 of the directional electromagnetic steel plates 21 in FIG. 13 (B), the width direction of the steel sheet 21 y-axis, the thickness direction of the steel sheet is z-axis, face the x = 0 on the side closer to the punch 24 of the die 22, defining the origin in the width direction of the center of the grain-oriented electrical steel sheet y = 0, the die 22 side surface of the oriented electrical steel sheet as z = 0 (FIG. 11 of the (B) shows the position of x = 0, y = 0, z = 0). The time and temperature at the origin (0,0,0), the opposite surface (i.e., the point (0,0, t)) from the die 22 at the origin of the average value of the temperature in the bending direction during processing It is defined as the temperature of the electromagnetic steel sheet. Temperature of origin (0, 0, 0) and the point (0,0, t) is the temperature at which the punch contacts the steel sheet can be evaluated by measuring a thermocouple. Note the thickness of the oriented electrical steel sheet of the above t.
[0054]
(Laminating step)
　Subsequently, in the laminating step, a plurality of bent bodies are stacked in the thickness direction. That is, the bending body 1, aligning the corner portion 3 to each other, and stacked superimposed in the thickness direction to form a substantially rectangular stack as viewed from the side. Thus, it is possible to obtain a wound core. The resulting wound core may be fixed using a known binding band and fastener if necessary.
[0055]
　The present invention is not limited to the above embodiment. The above embodiments are illustrative, have the technical idea substantially the same configuration described in the claims of the present invention, which achieves the same effect, the present invention be any one It is encompassed in the technical scope.
　For example, in the above description, a case has been described in which the bent body 1 is four stacked, the number of workpiece 1 bent to be laminated is not limited.
Example
[0056]
　Hereinafter, while examples of the present invention, further describes the technical contents of the present invention. The conditions in the examples that follow, an example of conditions adopted for confirming the workability and effects of the present invention, the present invention is not limited to this condition example. The present invention does not depart from the gist of the present invention, as long as they achieve the object of the present invention, it is capable of adopting various conditions.
[0057]
　As an experimental example A1 ~ A14, thickness relative to the base steel sheet is 0.27 mm, forsterite (Mg 2 SiO 4 and glass film (thickness 1.0 .mu.m) containing) film containing aluminum phosphate (thickness is 2.0 .mu.m) and were formed in this order, further, were prepared oriented electrical steel sheet obtained by dividing the magnetic domains by performing laser irradiation at 4mm intervals to the rolling direction and the direction perpendicular to the surface of the steel sheet.
　The corner portion forming regions of these oriented electrical steel sheet subjected to bending while controlling the temperature range of 25 ℃ ~ 1000 ℃, bending angle φ to obtain a bending member having a bending region of 45 °. Then, by laminating the bending member to obtain a wound core of dimensions shown in Figure 12.
　Moreover, Experimental Examples B1 ~ B14, C1 ~ C14, and the D1 ~ D14, the thickness of the base steel respectively 0.23 mm, 0.20 mm, a similar wound cores using grain-oriented electrical steel sheet was 0.18mm Obtained.
[0058]
Modification twin number of measurements of crystallization]
　from the winding core of the above experimental example was sheared samples from the region A shown in FIG. 12. The sample was observed with an optical microscope, and calculating the length 1mm Atari in the thickness direction of the center line, the number of deformation twins present in each of the bending region of the bent member. The results are shown in Tables 1 and 2.
　Note that variations are twins was confirmed by analysis assessed using scanning electron microscopy and the crystal orientation analysis software (EBSD).
[0059]
[Elution amount of measurement of phosphorus]
　from the winding core of the above experimental example was sheared samples from regions B1, B2 shown in FIG. 12.
　At this time, the region B1, the size of the flat portion of the resulting sample from B2 was sheared as both a width 30 mm × length 280 mm.
　These samples were each poured into water 200 cc, 30 minutes, after boiling at about 100 ° C., it was measured phosphorus eluted in water by a molybdenum blue (ascorbic acid reduction) absorption spectrophotometry as phosphate ion. Elution amount P of phosphorus from samples taken from the area B1 B1 elution amount P of phosphorus from the sample taken from the region B2 B2 from the difference between, was calculated elution amount of phosphorus from the corner portion. The results are shown in Tables 1 and 2.
[0060]
　Note that previously measured in water of phosphoric acid ions was confirmed to be less than the lower limit of quantitation (0.005 mg / l).
　Further, in the measurement of the elution amount of the phosphorus, where to form Sample width 50 mm × length 336 mm, it was measured similarly phosphorus elution amount, the phosphorus elution amount per unit area, the width 30 mm × length it was confirmed that it was the same as in the sample of 280mm.
[0061]
[Evaluation]
iron loss value measured in (1) wound core
　for wound core of Example, an excitation current method in the measurement method of the magnetic properties of electrical steel strip by the respective Epstein tester according to JIS C 2550-1, frequency 50Hz , was measured under the conditions of the magnetic flux density 1.7 T, iron loss W a was determined.
Iron loss value measured in (2) oriented electrical steel sheet
　from the wound cores of Examples, and the shear removed oriented electrical steel sheet, samples were taken of the width 60 mm × length 300mm comprising only the flat plate portion, the JIS C 2556 the electromagnetic steel veneer magnetic characteristics test by H coil method described, frequency 50 Hz, was measured under the conditions of the magnetic flux density 1.7 T, iron loss W B was determined.
(3) Building factor
　iron loss value W of the winding core which has been determined by the (1) A , and the iron loss value W of the electromagnetic steel veneer obtained in (2) B building factor by dividing (BF) I was determined. Does not occur sticking of the base steel sheets during lamination as BF is smaller in the present invention, it can be evaluated that the iron loss is reduced wound core. In the present application, the values of BF is the invention example of less than 1.00.
　The results are shown in Tables 1 and 2.
[0062]
[Table 1]

[0063]
[Table 2]

[0064]
[Summary of Results]
　By bending temperature of the corner portion formation region at the time of processing more than 0.99 ° C., the number of deformation twins per unit length can be reduced to below five were confirmed. It is possible to more suppress the number of deformation twins raise the bending temperature of the corner portion formation region at the time of processing, but when the temperature of the corner portion formation region at the time of bending is 600 ° C. or higher, from the corner portion elution of phosphorus increases, BF value is increased for. From this result, when the temperature of the bent corner portion formation region at the time of processing is above 600 ° C., the cracking of the coating containing phosphorus in the bending region occurs, it is presumed that sticking of steel sheets occurs.
　Bending in the invention example of controlling the temperature to 500 ° C. from 0.99 ° C. corner portion formation region at the time of processing, in a side view, the number of deformation twins present in the bending area, the thickness direction of the center line in the bending area not more than 5 fibers per length 1 mm, and elution of phosphorus from the corner portion when boiled in water for 30 minutes, the surface area 1m corner 2 becomes less per 6.0 mg, iron loss value as wound cores also, BF value is low, while having a bending region, iron loss was revealed that a wound core which is suppressed.
Industrial Applicability
[0065]
　According to the present invention, while having a bending region, iron loss wound core which is suppressed, and a manufacturing method thereof can be provided.
DESCRIPTION OF SYMBOLS
[0066]
1,1a-oriented electrical steel sheet
2 laminated body
3 corners
4, 4a, 4b plane portion
5, 5a, 5b, 5c bending area
6 joints
7 deformation twins
10 vol core wound core
21 oriented electrical steel sheet
22 die
23 guides
24 punch
25 carrying direction
26 pressing direction

The scope of the claims
[Requested item 1]
　A plurality of bending body coating containing phosphorus is formed from the formed oriented electrical steel sheet on the surface, a wound core composed by stacking in its thickness direction,
　the bent body, a flat portion is formed in a rectangular shape by each have are four and a corner portion adjacent to the flat portion,
　the corner portion, as viewed from the side, the total bending angle has a bending region is substantially 90 ° ,
　in a side view, the number of deformation twins present in the bent region, the is at the bend region below five per length 1mm of the thickness direction of the center line,
　the corner when boiled in water for 30 minutes elution of phosphorus from the Department is, the surface area 1m corner 2 or less per 6.0mg
wound core, characterized in that.
[Requested item 2]
　The oriented electrical steel sheet, the steel sheet local distortion is applied to the surface, or a steel plate having grooves formed on a surface
wound core according to claim 1, characterized in that.
[Requested item 3]
　Si content of the grain-oriented electrical steel sheet is 2.0 to 5.0 mass%
wound core according to claim 1, characterized in that.
[Requested item 4]
　The bent region, in a side view of the bending member, the bending D and point E a point on the line La, which represents an interior surface of the workpiece, and a point F and a point on the line Lb representing the outer surface of the bending member when defining the G as follows, the bending of the point on the line La which represents the inner surface D and the point E and separated by a line, the bent body point F and the point on the line Lb representing the outer surface of the separated by a line with a G, a straight line connecting the point G and the point D, and a region surrounded by the straight line connecting the point F and the point E
wound core according to claim 1, characterized in that .
　
　in side view, the central point A of the curvature radius of the curved section included in the line La which represents the inner surface of the bending member, the outer surface of the bending member the obtained by extending the straight portion adjacent to the respective sides of the curved portion contained in the line Lb representing two imaginary lines Lb-elongation1, Lb-elongation2 line AB connecting the point of intersection B of, the bent body the point of intersection with the line representing the inner surface as the origin C,
　along the lines La which represents the inner surface of the bending member from the origin C, and a point at a distance m, represented in one direction by the following formula (1) and point D,
　along the lines La which represents the inner surface of the bending member from the origin C, and a point distant by the distance m in the other direction to the point E,
　contained in the line Lb representing the outer surface of the bending member among the straight portion to be A straight portion opposed to the point D, and point G the intersection of the imaginary line passing through and the point D drawn perpendicular to the straight portion facing the point D,
　the line representing the outer surface of the bending member among the straight portion included in Lb, and a straight portion opposed to the point E, a point F of intersection between an imaginary line and drawn perpendicular to the straight portion facing the point E passing through the point E to.
　Equation (1): m = r × ([pi / 4)
(in the formula (1), m represents the distance from the origin C, r denotes the distance from the center point A to the origin C (radius of curvature)).
[Requested item 5]
　A method of manufacturing a wound core according to claim 1,
　a preparation step of preparing a plurality of oriented electrical steel sheet having a coating containing phosphorus on the surface,
　pre-assigned to the plurality of the grain oriented electrical steel sheet and each corner portion forming region, by bending in a state where the temperature was set to 0.99 ° C. or higher 500 ° C. or less of the corner portion forming region, bending forming a plurality of bending which is a substantially rectangular shape in a side view step a,
　a plurality of the bending body, and a laminating step of laminating a thickness direction
method of manufacturing a wound core, characterized in that it comprises a.