JP2022070241A - Winding iron core - Google Patents

Abstract

To provide a winding iron core that is formed by a method of laminating bent steel plates to form a winding iron core, the winding iron core being highly efficient by appropriately arranging flat surface parts.SOLUTION: A winding iron core includes: directional electromagnetic steel plates 1 laminated in a plate thickness direction; and a winding iron core body substantially rectangular in a side view. In the winding iron core body, a flat surface part and a bent surface part alternately continue to each other in a longer direction. Also, an inner surface side curvature radius r in a side surface view of the bent surface part is not larger than 3 mm, and when a region where a bent surface part with 10-80° angles and a flat surface part with a length of 3-8 mm alternately continue to each other in a circumferential direction of the winding iron core in a side view of at least one bent surface part of an arbitrary one of the laminated directional electromagnetic steel plates is a region A, the number of the directional electromagnetic steel plates in which the region A exists is Ma, and a total number of laminated layers is Mtotal, Ma/Mtotal≥0.30(1) is satisfied.SELECTED DRAWING: Figure 1

Description

The present invention relates to a wound iron core.

The grain-oriented electrical steel sheet is a steel sheet containing 7% by mass or less of Si and having a secondary recrystallized texture in which secondary recrystallized grains are accumulated in the {110} <001> orientation (Goss orientation). The magnetic properties of grain-oriented electrical steel sheets are greatly affected by the degree of integration in the {110} <001> orientation. In the grain-oriented electrical steel sheets that have been put into practical use in recent years, the angle between the <001> direction of the crystal and the rolling direction is controlled so as to be within a range of about 5 °. The directional control technology ensures high magnetic flux density and low iron loss, which are the main magnetic characteristics.

Electrical steel sheets are laminated and used for iron cores of transformers, etc., but conventionally, as described in Patent Document 4, for example, the steel sheets are wound into a cylindrical shape and then laminated in a tubular shape. A method of removing strain and maintaining a shape by forming a body into a rectangular shape by pressing and annealing is widely known.

On the other hand, as another method for manufacturing the wound iron core, the steel plate portion that becomes the corner portion of the wound iron core is bent in advance so that a relatively small bent region having a radius of curvature of 3 mm or less is formed, and the bent steel plate is formed. Disclosed are techniques such as those in Patent Documents 5 to 8 in which the above-mentioned steel cores are laminated to form a wound steel core. According to the manufacturing method, the large-scale pressing process as in the conventional case is not required, the steel sheet is precisely bent to maintain the iron core shape, and the processing strain is concentrated only on the bent portion (corner portion). It is also possible to omit distortion removal, and the industrial merit is greatly being applied.

Japanese Unexamined Patent Publication No. 2001-192785 Japanese Unexamined Patent Publication No. 2005-240079 Japanese Unexamined Patent Publication No. 2012-0522229 Japanese Unexamined Patent Publication No. 2005-286169 Japanese Patent No. 6224468 Japanese Unexamined Patent Publication No. 2018-148036 Australian Patent Application Publication No. 2012337260 International Publication No. 2018/131613

The inventors of the present application have bent a steel plate in advance so as to form a relatively small bending region having a radius of curvature of 3 mm or less, and laminated the bent steel plates to form a wound iron core. We examined the further reduction of iron loss in the iron core. The entire shape of the iron core is formed by alternately arranging bent portions and flat portions, and by limiting the deformation region to a bent portion that is very narrow with respect to the entire iron core, after the iron core is formed (after bending). ) Is one of the merits that good iron core efficiency can be exhibited without annealing. For this reason, many studies have been conducted on the morphology and structure of the bent portion, but there are few cases of examination based on the technical idea of optimizing the arrangement and configuration of the bent portion in relation to the flat portion.

The present inventor examined the arrangement of the bent portions, specifically, the distance between the adjacent bent portions (the length of the flat portion). As a result, it was found that when the iron core member is bent and deformed by a specific angle, the iron core efficiency can be improved by appropriately controlling the length of the flat surface portion in the region.

In the conventional iron core design, for example, in the case of a substantially rectangular iron core shape having four corners having a bending angle of 90 °, a design in which two 45 ° bent portions are arranged at each corner or a design of 30 ° Designs such as arranging three bent portions at a time have been made. Further, it was designed so that the length of the flat surface portion arranged at the corner portion becomes longer toward the outer member, as the total extension distance of the outer circumference becomes longer toward the outer side in the laminating direction of the steel plate. In particular, as the number of laminated steel sheets increased and the laminated thickness of the core became thicker, the outer peripheral members had to be lengthened.

On the other hand, the present inventors have studied a design in which the length of the flat surface portion arranged at the corner portion is limited to a specific range and is almost constant. As a result, it was confirmed that the iron core efficiency is improved by designing the bent portion in the corner portion to be arranged at a relatively short distance. From this point of view, we examined various shapes and succeeded in identifying the characteristics of the appropriate flat surface arrangement.

The present invention has been made in view of the above problems. The steel sheet is bent in advance so that a relatively small bent region having a radius of curvature of 3 mm or less is formed, and the bent steel sheets are laminated to form a wound steel core. It is an object of the present invention to provide a wound steel core having improved core efficiency by appropriately arranging flat portions having an appropriate length in the wound steel core manufactured by the above method.

In order to achieve the above object, the wound core according to the present invention is a wound core in which grain-oriented electrical steel sheets are laminated in the plate thickness direction and has a substantially rectangular shape in a side view.
In the grain-oriented electrical steel sheet, flat surfaces and bent portions are alternately continuous in the longitudinal direction.
The radius of curvature r on the inner surface side in the side view of the bent portion is 3 mm or less, and is
The grain-oriented electrical steel sheet is by mass%,
Si: contains 2.0 to 7.0%, has a chemical composition with the balance consisting of Fe and impurities, and has a chemical composition.
In the side view of grain-oriented electrical steel sheets having a texture oriented in the Goss direction and laminated.
Area A is a region in which a bent portion having an angle of 10 ° or more and 80 ° or less and a flat portion having a length of 3 to 8 mm are alternately continuous in the circumferential direction of the wound steel core, and the region A is present in the grain-oriented electrical steel sheet. When the number of sheets is Ma, the total number of laminated sheets is set to Mtotal.
Ma / Mtotal ≧ 0.30 ・ ・ ・ ・ ・ (1)
It is characterized by satisfying.

According to the present invention, the steel sheet is bent in advance so that a relatively small bent region having a radius of curvature on the inner surface side of 3 mm or less is formed, and the bent steel sheets are laminated to form a wound steel core. Good core efficiency can be obtained in the wound core.

It is a perspective view which shows typically one Embodiment of the winding iron core which concerns on this invention. It is a side view of the winding iron core shown in the embodiment of FIG. It is a side view schematically showing another embodiment of the winding iron core which concerns on this invention. It is a side view schematically showing an example of the one-layer grain-oriented electrical steel sheet constituting the winding iron core which concerns on this invention. It is a side view schematically showing another example of the one-layer grain-oriented electrical steel sheet constituting the winding iron core which concerns on this invention. It is a side view schematically showing an example of the bent part of the grain-oriented electrical steel sheet constituting the winding iron core which concerns on this invention. It is a schematic diagram which shows the 1st example of the laminated state of a bent part and a flat part which concerns on embodiment of this invention. It is a schematic diagram which shows the 2nd example of the laminated state of a bent part and a flat part which concerns on embodiment of this invention. It is a schematic diagram which shows the 3rd example of the laminated state of the bent part and the flat part which concerns on embodiment of this invention. It is a schematic diagram which shows the 4th example of the laminated state of a bent part and a flat part which concerns on embodiment of this invention. It is a schematic diagram which shows the dimensional parameter of the winding iron core manufactured in Examples 1 to 40.

Hereinafter, the wound core according to the present invention will be described in detail in order. However, the present invention is not limited to the configuration disclosed in the present embodiment, and various modifications can be made without departing from the spirit of the present invention. The numerical limit range described below includes the lower limit value and the upper limit value. Numerical values that indicate "greater than" or "less than" do not fall within the numerical range. Further, "%" regarding the chemical composition means "mass%" unless otherwise specified.
In addition, as used in the present specification, terms such as "parallel", "vertical", "identical", "right angle", and values of length and angle, etc., which specify the shape and geometric conditions and their degrees, are used. Is not bound by the strict meaning, but is interpreted to include the range in which similar functions can be expected.
Further, in the present specification, the “oriented electrical steel sheet” may be simply referred to as “steel sheet” or “electrical steel sheet”, and the “rolled steel core” may be simply referred to as “iron core”.

The wound steel core according to the embodiment of the present invention is a wound steel core in which grain-oriented electrical steel sheets are laminated in the plate thickness direction and has a substantially rectangular shape in a side view.
In the grain-oriented electrical steel sheet, flat surfaces and bent portions are alternately continuous in the longitudinal direction.
The radius of curvature r on the inner surface side in the side view of the bent portion is 3 mm or less, and is
The grain-oriented electrical steel sheet is by mass%,
Si: contains 2.0 to 7.0%, has a chemical composition with the balance consisting of Fe and impurities, and has a chemical composition.
In a side view of any grain-oriented electrical steel sheet having a texture oriented in the Goss orientation and laminated.
Area A is a region in which a bent portion having an angle of 5 ° or more and 80 ° or less and a flat portion having a length of 3 to 8 mm are alternately continuous in the circumferential direction of the wound steel core, and the region A is present in the grain-oriented electrical steel sheet. When the number of sheets is Ma, the total number of laminated sheets is set to Mtotal.
Ma / Mtotal ≧ 0.30 ・ ・ ・ ・ ・ (1)
It is characterized by satisfying.

1. 1. Shape of Winding Core and Electrical Steel Sheet First, the shape of the wound core of the present invention will be described. The shapes of the rolled iron core and the grain-oriented electrical steel sheet described here are not particularly new. For example, it conforms to the shapes of the known wound steel cores and grain-oriented electrical steel sheets introduced as Patent Documents 5 to 8 in the background technique.
FIG. 1 is a perspective view schematically showing an embodiment of a wound iron core. FIG. 2 is a side view of the wound iron core shown in the embodiment of FIG. Further, FIG. 3 is a side view schematically showing another embodiment of the wound iron core.
In the present invention, the side view means to see in the width direction (Y-axis direction in FIG. 1) of the elongated grain-oriented electrical steel sheet constituting the wound steel core, and the side view is visually recognized by the side view. It is a figure (the figure in the Y-axis direction of FIG. 1) which showed the shape | shape.

The wound core of the present invention includes a wound core body having a substantially rectangular shape in a side view. The main body of the rolled iron core has a laminated structure in which grain-oriented electrical steel sheets are stacked in the plate thickness direction and has a substantially rectangular shape in a side view. The wound core body may be used as it is as a wound core, or may be provided with a known fastener such as a binding band in order to fix the wound core as needed.

In the present invention, the iron core length of the wound iron core body is not particularly limited, but even if the iron core length changes in the iron core, the iron loss generated in the bent portion is constant because the volume of the bent portion is constant, and the iron core length is constant. The longer the length, the smaller the volume fraction of the bent portion, and the smaller the influence on the deterioration of iron loss. Therefore, the length is preferably 1.5 m or more, and more preferably 1.7 m or more. In the present invention, the core length of the wound core body means the peripheral length at the center point in the stacking direction of the wound core body from the side view.

The wound iron core of the present invention can be suitably used for any conventionally known application.

As shown in FIGS. 1 and 2, in the wound steel core main body 10, the flat surface portion 4 and the corner portion 3 are alternately continuous in the longitudinal direction, and the angle formed by the two adjacent flat surface portions 4 in each corner portion 3 is formed. The grain-oriented electrical steel sheet 1 having a temperature of 90 ° includes a portion stacked in the plate thickness direction, and has a substantially rectangular laminated structure 2 in a side view. From another point of view, the wound core body 10 has an octagonal laminated structure 2. In the present embodiment, the wound core body 10 has an octagonal laminated structure, but the present invention is not limited to this, and the wound core body is made of a plurality of polygonal annular directional electromagnetic steel sheets in a side view. It suffices that the grain-oriented electrical steel sheets are laminated in the thickness direction, and the plane portions and the bent portions are alternately continuous in the longitudinal direction (circumferential direction).

Hereinafter, the winding iron core main body 10 will be described as having a substantially rectangular shape having four corner portions 3.
Each corner portion 3 has two bent portions 5 having a curved shape in a side view of the grain-oriented electrical steel sheet 1, and has a second flat portion 4a between adjacent bent portions 5, 5. Moreover, the total bending angle of each of the two bending portions 5 and 5 existing in one corner portion 3 is 90 °.
Further, as shown in FIG. 3, each corner portion 3 has three bent portions 5 having a curved shape in the side view of the grain-oriented electrical steel sheet 1, and is between adjacent bent portions 5, 5. It has a second flat surface portion 4a, and the total bending angle of each of the three bending portions 5, 5 and 5 existing in one corner portion 3 is 90 °.

Further, each corner portion 3 may have four or more bent portions, and also in this case, a second flat surface portion 4a is provided between the adjacent bent portions 5 and 5, and one. The total bending angle of each of the four or more bending portions 5 existing in the corner portion 3 is 90 °. That is, each corner portion 3 is arranged between two adjacent first flat surface portions 4 and 4 arranged at right angles, and has two or more bent portions 5 and one or more second flat surface portions 4a. ing.
Further, in the wound core main body 10 shown in FIG. 2, the bent portion 5 is arranged between the first flat surface portion 4 and the second flat surface portion 4a, but in the wound iron core main body 10 shown in FIG. Bending portions 5 are arranged between the flat surface portion 4 of 1 and the second flat surface portion 4a and between the two second flat surface portions 4a and 4a, respectively. That is, the second flat surface portion 4a may be arranged between two adjacent second flat surface portions 4a, 4a.

Further, in the wound core main body 10 shown in FIGS. 2 and 3, the length of the first flat surface portion 4 in the longitudinal direction (circumferential direction of the wound iron core main body 10) is longer than that of the second flat surface portion 4a. However, the lengths of the first flat surface portion 4 and the second flat surface portion 4a may be equal.
In the present specification, the "first flat surface portion" and the "second flat surface portion" may be simply referred to as "flat surface portions", respectively.
Each corner portion 3 of the grain-oriented electrical steel sheet 1 has two or more bent portions 5 having a curved shape in a side view, and the bending angle of each of the bent portions existing in one corner portion. The total is 90 °. The corner portion 3 has a second flat surface portion 4a between the adjacent bent portions 5 and 5. Therefore, the corner portion 3 is configured to include two or more bent portions 5 and one or more second flat surface portions 4a.
The embodiment of FIG. 2 is a case where two bent portions 5 are provided in one corner portion 3. The embodiment of FIG. 3 is a case where three bent portions 5 are provided in one corner portion 3.

As shown in these examples, in the present invention, one corner portion can be composed of two or more bent portions, but from the viewpoint of suppressing the generation of strain due to deformation during processing and suppressing iron loss, the bent portion. The bending angle φ (φ1, φ2, φ3) of 5 is preferably 60 ° or less, and more preferably 45 ° or less.
In the embodiment of FIG. 2 having two bent portions in one corner portion, for example, φ1 = 60 ° and φ2 = 30 °, or φ1 = 45 ° and φ2 = 45 °, from the viewpoint of reducing iron loss. And so on. Further, in the embodiment of FIG. 3 having three bent portions in one corner portion, for example, φ1 = 30 °, φ2 = 30 °, φ3 = 30 °, etc. can be set from the viewpoint of reducing iron loss. Further, from the viewpoint of production efficiency, it is preferable that the bending angles are the same. Therefore, when one corner has two bending portions, it is preferable that φ1 = 45 ° and φ2 = 45 °, and 1 In the embodiment of FIG. 3 having three bent portions at one corner portion, for example, φ1 = 30 °, φ2 = 30 ° and φ3 = 30 ° are preferable from the viewpoint of reducing iron loss.

The bent portion 5 will be described in more detail with reference to FIG. FIG. 6 is a diagram schematically showing an example of a bent portion (curved portion) of a grain-oriented electrical steel sheet. The bending angle of the bent portion means the angle difference generated between the straight portion on the rear side and the straight portion on the front side in the bending direction in the bent portion of the directional electromagnetic steel plate, and is bent on the outer surface of the directional electromagnetic steel plate. It is expressed as the angle φ of the complementary angle of the angle formed by the two virtual lines Lb-elongation 1 and Lb-elongation 2 obtained by extending the straight line portion which is the surface of the flat surface portion on both sides of the portion. At this time, the point where the extending straight line separates from the surface of the steel sheet is the boundary between the flat surface portion and the bent portion on the surface on the outer surface side of the steel sheet, and is the point F and the point G in FIG.

Further, a straight line perpendicular to the outer surface of the steel sheet is extended from each of the points F and G, and the intersections with the surface on the inner surface side of the steel sheet are defined as points E and D, respectively. The points E and D are the boundaries between the flat surface portion and the bent portion on the inner surface side of the steel sheet.
In the present invention, the bent portion is a portion of the grain-oriented electrical steel sheet surrounded by the points D, E, F, and G in the side view of the grain-oriented electrical steel sheet. In FIG. 6, the surface of the steel plate between the points D and E, that is, the inner surface of the bent portion is shown as La, and the surface of the steel plate between the points F and G, that is, the outer surface of the bent portion is shown as Lb.

Further, in the present invention, the radius of curvature on the inner surface side of the bent portion is defined in the side view of the bent portion. Taking FIG. 6 as an example, a method of determining the radius of curvature on the inner surface side of the bent portion will be specifically described. First, in each of the flat surface portions on both sides of the bent portion, a straight line that is in contact with the straight line portion that is the surface of the flat surface portion over at least 1 mm is determined. These are designated as virtual lines Lb-elongation1 and Lb-elongation2, respectively, and this intersection is defined as a point B. Ideally, the length of the line segment BF and the length of the line segment BG are the same, but in reality, there may be some differences due to variations in processing conditions and unavoidable variations. Even in such a case, the points F'and G'are determined from the points B, F and G so that the effect of the present invention can be appropriately evaluated. That is, the longer distance between the line segment BF and the line segment BG is defined as LL (for example, the line segment BG is longer than the line segment BF), and the distance from the point B to the point F on the virtual line Lb-elongation1. A point separated by LL is defined as a point F', and a point separated by a distance LL from the point B toward the point G on the virtual line Lb-elongation 2 is defined as a point G'. At this time, either the point F'or the point G'corresponds to the original point F or the point G, respectively (for example, when the line segment BG is longer than the line segment BF, the point G'is the original point G. Matches.).
When the lengths of the line segment BF and the line segment BG are equal, in FIG. 6, the point F'consists with the original point F, and the point E'described below coincides with the original point E. Will be done.
Then, a straight line perpendicular to the outer surface of the steel plate is extended from each of the points F'and G', the intersection is set as the center of curvature A, and the intersections of the line segment AF'and the line segment AG'and the surface La on the inner surface side of the steel plate are respectively. Let it be a point E'and a point D'. At this time, the circle passing through the points E'and D'with the point A as the center is a curved surface that approximates the bending portion in the present invention, and the length of the line segment AE'(which corresponds to the length of the line segment AD'). ) Is the radius of curvature on the inner surface side in the present invention.
In the wound steel core of the present invention, the radius of curvature on the inner surface side at each bent portion of each grain-oriented electrical steel sheet laminated in the plate thickness direction may have some variation. This fluctuation may be due to the molding accuracy, and it is possible that an unintended fluctuation may occur due to handling during laminating. Such an unintended error can be suppressed to about 0.3 mm or less in the current ordinary industrial manufacturing. When such fluctuation is large, a typical value can be obtained by measuring and averaging the inner surface side curvature radii for a sufficiently large number of steel plates. It is also possible to change it intentionally for some reason, but the present invention does not exclude such a form.
In the present invention, it is assumed that the radius of curvature r on the inner surface side is 3 mm or less. As will be described later, it is considered that the main action of the present invention is brought about by the magnetic domain control effect in the flat portion having a length of 3 to 8 mm, and the size of the bent portion that divides the flat portion is simply set in the corner portion. In, it is considered that it should not occupy a large area. In a wound steel core formed by laminating an electromagnetic steel sheet having a bent portion having a relatively small inner surface side radius of curvature, which is generally the object of the present invention, reducing the inner surface side radius of curvature of the bent portion is a magnetic characteristic. From the viewpoint, a well-known technique is preferable, and the technique has been developed in such a direction in the iron core. In the present invention, this is also taken into consideration, and the radius of curvature on the inner surface side of the bent portion is set to 3 mm or less. From the above two points, it is clear that the radius of curvature on the inner surface side is preferably small, preferably 2 mm or less, and more preferably 1 mm or less.

In the wound steel core of the present invention, the radius of curvature on the inner surface side at each bent portion of each grain-oriented electrical steel sheet laminated in the plate thickness direction may have some variation. This fluctuation may be due to the molding accuracy, and it is possible that an unintended fluctuation may occur due to handling during laminating. Such an unintended error can be suppressed to about 0.3 mm or less in the current ordinary industrial manufacturing. When such fluctuation is large, a typical value can be obtained by measuring and averaging the inner surface side curvature radii for a sufficiently large number of steel plates. Further, it is conceivable to intentionally change the radius of curvature on the inner surface side of the bent portion of the bent portion of the specific portion in the iron core for some reason, but the present invention does not exclude such a form.

The method for measuring the shape of the bent portion is not particularly limited, but the measurement can be performed by, for example, observing with a commercially available microscope (Nikon ECLIPSE LV150) at a magnification as required.
In the present invention, the efficiency of the wound iron core can be improved by controlling the shape of the bent portion described below to a specific range by setting the radius of curvature r on the inner surface side of the bent portion to a range of 3 mm or less. ..

4 and 5 are diagrams schematically showing an example of one layer of grain-oriented electrical steel sheet in a wound steel core main body. As shown in the examples of FIGS. 4 and 5, the grain-oriented electrical steel sheet used in the present invention is bent and has a corner portion 3 composed of two or more bent portions 5 and a flat surface portion. 4 is formed, and a substantially rectangular ring is formed in a side view through a joint portion 6 of the widthwise end faces of one or more grain-oriented electrical steel sheets.
In the present invention, the wound iron core main body may have a laminated structure having a substantially rectangular side view as a whole. As shown in the example of FIG. 4, one grain-oriented electrical steel sheet may form one layer of the wound steel core body via one joint portion 6, and is shown in the example of FIG. As described above, one grain-oriented electrical steel sheet constitutes about half of the winding core, and two grain-oriented electrical steel sheets form one layer of the wound core body via the two joints 6. There may be.

The thickness of the grain-oriented electrical steel sheet used in the present invention is not particularly limited and may be appropriately selected depending on the intended use, etc., but is usually in the range of 0.10 mm to 0.35 mm, preferably in the range of 0.10 mm to 0.35 mm. It is in the range of 0.15 mm to 0.23 mm.

2. 2. Form of bent portion and flat portion Here, the features of the form of the bent portion and the flat portion of the grain-oriented electrical steel sheet constituting the main body of the wound steel, which is one of the embodiments of the present invention, will be described with reference to FIGS. 7A to 7D. do.

In the present embodiment, the invention is defined by the form of the grain-oriented electrical steel sheet in the side view of the grain-oriented electrical steel sheet laminated as the wound steel core. In this side view, a bent portion having a bending angle of 5 ° or more and 80 ° or less (hereinafter, may be referred to as a “target bent portion”) and a flat portion having a length of 3 to 8 mm (hereinafter, “target flat portion”). ”) Is subject to the regulation. Then, in at least a part of the laminated grain-oriented electrical steel sheets, a region (hereinafter referred to as "region A") in which the target bent portion and the target plane portion are alternately continuous in the circumferential direction of the wound steel core is provided. exist.
Then, when the total number of laminated steel sheets is Mtotal and the number of grain-oriented electrical steel sheets in which the region A exists is Ma.
Ma / Mtotal ≧ 0.30 ・ ・ ・ ・ ・ (1)
To be satisfied.

The number of corners of the wound iron core assumed by the present invention is not limited, but is generally substantially rectangular in side view. That is, there are four corners bent at 90 °, and the flat surface between the corners is relatively long compared to the size of the corners. Taking this shape as a representative example, the above-mentioned features of the present invention will be described in a little more detail.

The bending angle of the target bent portion in the present invention is 80 ° or less. As described above, the iron core itself, which is the object of the present invention, is characterized in that the characteristics of the iron core are preferably controlled by dispersing the bending portions, and it is assumed that the angle of one bending is basically small. ing. However, in the present invention, it is necessary that the angle of one bending process, which is defined by the present invention, is small in relation to the mechanism for expressing the effect of the present invention, which will be described later. Although the details will be described later, the effect of the present invention is based on the subdivision of the magnetic domain by the bent portion, and if the bending angle becomes large and excessive strain is generated at the bent portion, the magnetic domain structure is not preferable. , The invention effect cannot be obtained. It is preferably 60 ° or less, more preferably 45 ° or less, still more preferably 30 ° or less. On the other hand, since the magnetic domain subdivision is brought about by the strain introduced in the steel sheet, if the bending angle is too small, the cost may increase due to the large number of bending points and the magnetic domain control effect itself may be weakened. Therefore, the bending angle of the target bent portion is set to 5 ° or more. It is preferably 10 ° or more, more preferably 15 ° or more.

The length of the wound iron core of the target plane portion in the present invention in the circumferential direction is 3 to 8 mm. As described above, this is related to the optimum size of the magnetic domain in the flat portion when the magnetic domain is subdivided by the bent portion. Generally, the crystal grain size of the grain-oriented electrical steel sheet is about 50 mm, and the magnetic domain also exists in this size. The technique of subdividing this to improve the magnetic properties is so-called "magnetic domain control", and the magnetic domain is subdivided by mechanical processing, etching, high energy ray irradiation, etc. in a local region of the steel sheet surface. The appropriate magnetic domain size at that time is said to be around 5 mm. The present invention applies the magnetic domain control technique utilized in a flat grain-oriented electrical steel sheet to a wound core manufactured by bending. Therefore, it is considered that the size of the target plane portion defined by the present invention is close to about 5 mm, which is the optimum magnetic domain size of the grain-oriented electrical steel sheet having a flat shape. It is preferably 4 to 7 mm.

In the present embodiment, the target bent portion and the target flat portion are alternately and continuously formed to secure a large bending angle of the total steel sheet in a relatively narrow region. That is, a portion corresponding to a corner portion in the rectangular iron core is formed. For example, in the case of a 90 ° corner portion, two 45 ° bent portions are arranged, and the length of the flat surface portion between the bent portions is designed to be 3 to 8 mm (see, for example, FIG. 7A). Alternatively, three 30 ° bent portions are arranged, and the length of each of the two flat portions between the bent portions is designed to be 3 to 8 mm (see, for example, FIG. 7D). In the following, in order to make the explanation easy to understand, the length of the flat surface portion will be described as 5 mm.

As described above, one steel plate constituting the core (for example, the nth steel plate laminated from the innermost steel plate toward the outer circumference) is arranged with, for example, two 45 ° bent portions, and the bent portion is arranged. When the length of the flat surface portion between the portions is designed to be 5 mm, the extending distance of the corner portion along the circumferential direction of the iron core is about 5 mm. Further, when three bent portions of 30 ° are arranged and the lengths of the two flat portions between the bent portions are designed to be 5 mm each, the extending distance of the corner portions is about 10 mm. This is the shape of one steel sheet, and if the extending distance of the corner portion is constant in all the laminated electrical steel sheets, the steel sheets bent by the design may be laminated. However, the circumference of the iron core becomes longer toward the outer peripheral portion of the laminate. Further, in order to prevent gaps from being formed in the steel plates laminated at the corners, the extension distance of the corners is generally designed to be long. Specifically, when the (n + 1) th steel plate outside the nth steel plate is laminated so that the flat surface portion is in contact with each other as much as possible, the bent portion at 45 ° becomes a uniform angle 22.5. Since the steel plate bends at the ° position, the length of the flat surface portion becomes longer than 5 mm. For example, when the length between the bent portions of the flat surface portion of the innermost n = 1st steel plate is _L0 , the product thickness is t, the number of laminated sheets is n, and the space factor when laminated is vf. T is n × t / vf, and the length of the nth plane portion becomes as long as L ₀ + 2T · tan 22.5 ° C. (FIG. 7A). That is, assuming that the steel plate laminated on the innermost circumference is bent by the above design (the length of the flat surface portion is 5 mm), it is necessary to lengthen the flat surface portion toward the outer peripheral side of the steel plate laminated on the outer circumference. Then, when the laminated thickness is more than a certain level, the length of the flat surface portion in the corner portion cannot be maintained to 8 mm or less. When the length of the flat surface portion becomes long as described above, the characteristics are deteriorated from the viewpoint of the above-mentioned magnetic domain control. In order to avoid this deterioration, in the present embodiment, a design is made so as to prevent the length of the flat surface portion from increasing in the outer peripheral portion.

One is, for example, as shown in FIG. 7B, in which the flat surface portions are laminated while the length is kept constant. Alternatively, as shown in FIG. 7C, the length of the flat surface portion is lengthened toward the outer circumference, but when the length becomes excessively long, a steel plate having a shorter flat surface portion is laminated on the outer peripheral side. Is. By doing so, even if the extending distance of one corner portion becomes long, it is possible to enjoy a good magnetic domain subdivision effect at the corner portion.

Here, to reiterate the difference between FIGS. 7A, 7B, and 7C, the steel plate laminating method of FIG. 7A is a normal unicore laminating method, and the steel plates contact as much as possible including the flat surface portion of the steel plate at the corner portion. In contrast to the laminating method, in FIG. 7B, in order to make the length L of the flat surface portion of the steel plate portion in the corner portion in the range of 3 mm to 8 mm, a gap (a gap generated between the flat plate portions of the corner portion) is generated. The white portion between the steel plates (black portions) in FIG. 7B) is uniformly distributed in the thickness direction. Further, in FIG. 7C, the steel plates are brought into contact with each other as much as possible including the flat portion of the steel plate at the corner portion, and when the length L of the flat portion of the steel plate at the corner portion increases with the number of stacked sheets, L is shortened again to 3 mm. In order to make the range of about 8 mm, the voids generated between the steel plates in the flat portion at the corners are integrated between the steel plates having a long L and the steel plates having a short L.

Further, as a matter of course, an intermediate laminating method between FIGS. 7A and 7B is also possible, and a combination of FIG. 7B and FIG. 7C is also possible, and the effect of magnetic domain subdivision can be obtained if the requirements of the present invention are satisfied. You can enjoy it.
Furthermore, it is also possible to maintain the length of the flat surface portion to 8 mm or less by increasing the number of bent portions at a specific time point toward the outer circumference as shown in FIG. 7D. For example, when two 45 ° bent portions are arranged on the innermost circumference and the length of the flat surface portion between the bent portions is designed to be 3 mm, the outer peripheral portion has 3 bent portions of 30 ° from a certain position. One is arranged so that the length of the two flat portions between the bent portions can be maintained at about 5 mm each. Further, if the length of the flat surface portion is excessively increased at the outer peripheral portion, four 22.5 ° bent portions are arranged on the outer peripheral portion, and the three flat portions between the bent portions are arranged. The length should be maintained at about 5 mm each.

In FIGS. 7B, 7C, and 7D, the lengths of all the flat surfaces in the corners are set to satisfy 3 to 8 mm, but some of the flat surfaces in the corners are 3 to 8 mm in length. If satisfied, the effect of the invention can be obtained. There may be a flat surface portion having an unspecified length in the stacking direction. Further, there may be a flat surface portion having an unspecified length in the circumferential direction of the iron core. In this way, when a part of the flat surface portion in the corner portion does not satisfy the invention regulation, if the ratio of the flat surface portion satisfying the invention regulation is the same, the flat surface portion satisfying the invention regulation is arranged on the inner peripheral side. Is preferable. This is because when the iron core is excited, the magnetic flux is concentrated on the inner peripheral side, and it is advantageous to enjoy the magnetic domain control effect in this region.

In the embodiment of the present invention, the above configuration is defined as follows. That is, in the side view of the laminated grain-oriented electrical steel sheets, a region in which a bent portion having an angle of 5 ° or more and 80 ° or less and a flat portion having a length of 3 to 8 mm are alternately continuous in the circumferential direction of the wound steel core is formed. When the area A is set and the number of grain-oriented electrical steel sheets in which the area A exists is Ma, the total number of laminated sheets is set to Mtotal.
Ma / Mtotal> 0.30 ・ ・ ・ ・ ・ (1)
To be satisfied.
Ma / Mtotal is preferably 0.50 or more, more preferably 0.8 or more. Basically, it is preferable that all the laminated steel plates of the iron core, that is, from the innermost steel plate to the outermost steel plate meet the provisions of the present invention, that is, Ma / Mtotal = 1.00.
Further, although the invention effect can be obtained if the equation (1) is satisfied for the entire iron core, the equation (1) is satisfied even if the equation (1) is limited to one corner portion, and all the corner portions are further satisfied. It is preferable to satisfy the formula (1).

In a normal unicore, the number of laminated steel sheets is 100 or more and the laminated thickness is often 40 mm or more, although it depends on the design. In the ordinary laminating method as shown in FIG. 7A, Ma / Mtotal = 1.00. It is not possible. As described above, when the number of laminated steel sheets increases and the laminated thickness of the core becomes thicker, the outer peripheral member has to be lengthened, and in the normal laminating method as shown in FIG. 7A, the laminated thickness of the core When the thickness is 16 mm or more, the formula (1) is satisfied and good core characteristics cannot be obtained. As a specific method for making the length of the flat surface portion between the bent portions in the range of 3 mm to 8 mm in all the laminated steel plates, as described above, as shown in FIG. 7B, the corner portion The laminating method may be different from the usual laminating method, and as shown in FIG. 7C, the number of bent portions at the corners remains the same, and the nth next (n + 1) in the range where the outer peripheral portion does not exceed 8 mm. ) A method of providing gaps in the corners in the stacking with the first sheet, as shown in FIG. 7D, in the stacking with the next (n + 1) th sheet in the range where the outer peripheral portion does not exceed 8 mm, the gaps in the corners. There is a method of further increasing the number of bent portions, and a method of combining them. Further, if the angle of the bent portion and the length of the flat portion can be maintained within an appropriate range, when the method shown in FIG. 7D is adopted and the number of the bent portions is increased, the number of the bent portions is increased by two or more at a time. It doesn't matter.
Although the length of the flat surface portion between the bent portions has been described here as being in the range of 3 mm to 8 mm, the length of the flat surface portion of a part of the laminated steel plates is within the range satisfying the above formula (1). It is also possible that the size is less than 3 mm or more than 8 mm.

In the present invention, the features of FIGS. 7B, 7C and 7D described above are defined as follows.
The first defines the features of FIG. 7B as preferred. In this regulation,
Regions A having the same length in the circumferential direction of the iron core of the target plane portion are laminated in parallel and continuously with the target plane portions.
The bending angle of the target bent portion of the region A is Φ, the thickness of the steel plate laminated in the region is H in the direction perpendicular to the target plane portion of the region where the target plane portions are laminated in parallel and continuously. When the stacking thickness is Lx,
Lx / H / cosΦ: 0.97 to 1.03 ・ ・ ・ ・ ・ (2)
To be satisfied.
Here, the value on the left side of Eq. (2) is preferably 1.00, but in reality, some gaps and shape variations occur in the laminating of steel plates, so a fluctuation of about 3% is allowed. There is. The equation (2) means that Lx / H / cosΦ, which is the value on the left side, is 0.97 to 1.03, in other words, 0.97 ≦ Lx / H / cosΦ ≦ 1.03. Means.
In the wound steel core shown in FIG. 7B, the shapes of the corner portions of all the steel plates are the same in the side view, and voids are formed between the target plane portions forming the corner portions in the steel plates adjacent to each other in the stacking direction. Has been done. The shapes of each void in the side view are the same. Here, the laminated thickness Lx is different from the laminated thickness L3 in that the target plane portion is limited to a region where the target plane portions are laminated in parallel and continuously (hereinafter, also referred to as a target region). When the target plane portion is laminated in parallel and continuously over the entire area in the stacking direction, Lx = L3, but the target plane portion is laminated in parallel and continuously only in a part of the stacking direction. If so, Lx <L3. The laminated thickness Lx can be, for example, the laminated thickness of the steel sheet in the first flat surface portion adjacent to the corner portion including the target region.

The second defines the features of FIG. 7C as preferred. In this regulation,
At least two regions A are laminated and arranged in parallel with the target plane portion of each region A.
Let Φ be the bending angle of the target bent portion constituting the region A.
Let Ln be the length of the target plane portion arranged on the inner surface side of the iron core in the circumferential direction of the iron core.
Let Lm be the length of the target plane portion arranged on the outer surface side of the iron core in the circumferential direction of the iron core.
Further, when the distance between the above two target plane portions is Lh,
Lm <Ln ・ ・ ・ ・ ・ (3)
Lh / {(Ln-Lm) / 2} / tanΦ> 0.98 ・ ・ ・ ・ ・ (4)
To be satisfied.
Here, the value on the left side of the equation (4) is preferably more than 1.00, but in reality, some gaps and shape variations occur in the laminating of the steel sheets, so a fluctuation of about 2% is allowed. ing.
The wound core shown in FIG. 7C is provided with four laminated bodies in which steel plates are laminated (the number of laminated bodies is not limited to four, but the wound core shown in FIG. 7C has a plurality of laminated bodies. It is a multi-block type having a laminated body (block)). In each laminated body, the number of bent portions at the corners of the steel sheet is the same, but the length of the plane portion in the circumferential direction is longer as the steel plate is located outside in the radial direction. The number of bent portions is the same even at the corner portions of different laminated bodies. Although the four laminated bodies are laminated in the laminating direction of the steel sheets, a gap is provided between the corner portions of each other. The length of the target plane portion arranged on the inner surface side of the iron core across the void is the Ln, and the length of the target plane portion arranged on the outer surface side of the iron core across the void is the length in the circumferential direction of the iron core. Is Lm, and the distance between the target plane portions, which are Ln and Lm, in the stacking direction is Lh.
In addition, Ln and Lm in FIG. 7C are described assuming that the lengths of the flat surface portions forming the corner portions are all within the range of 3 mm to 8 mm (all are in the region A). However, the present embodiment is not limited to this, and the length of a part of the flat surface portion forming the corner portion can be less than 3 mm or more than 8 mm within the range satisfying the above formula (1). ..

The third defines the features of FIG. 7D as preferred. In this regulation,
At least two regions A are arranged so that at least one of the target plane portions of each region A is stacked in a non-parallel manner.
Of the two regions A, for the region A arranged on the inner surface side of the iron core, the bending angle of the target bent portion is Φn, the number of the target bent portions is Rn, and the average length of the target plane portion in the iron core circumferential direction is set. Let it be Ln
Of the two regions A, for the region A arranged on the outer surface side of the iron core, the bending angle of the target bent portion is Φm, the number of the target bent portions is Rm, and the average length of the target plane portion in the iron core circumferential direction is set. When it is Lm,
Φm <Φn ・ ・ ・ ・ ・ (5)
Rm> Rn ・ ・ ・ ・ ・ (6)
Lm <Ln ・ ・ ・ ・ ・ (7)
To be satisfied.
The wound core shown in FIG. 7D is provided with three laminated bodies in which steel plates are laminated (the number of laminated bodies is not limited to three, but the wound core shown in FIG. 7D has a plurality of laminated bodies. It is a multi-block type having a laminated body (block)). In each laminated body, the number of bent portions at the corners of the steel sheet is the same, but the length of the plane portion in the circumferential direction is longer as the steel plate is located outside in the radial direction. The number of bent portions is different in the corner portions of different laminated bodies. The number of bent portions gradually increases (one by one in the illustrated example) as the laminated body is located on the outer side in the radial direction. Although the four laminated bodies are laminated in the laminating direction of the steel sheets, a gap is provided between the corner portions of each other. The bending angle of the target bent portion arranged on the inner surface side of the iron core across the gap is the Φn, the number of the target bent portions is the Rn, and the average length of the target plane portion in the circumferential direction of the iron core is the Ln. .. The bending angle of the target bent portion arranged on the outer surface side of the iron core across the gap is the Φm, the number of the target bent portions is the Rm, and the average length of the target plane portion in the circumferential direction of the iron core is the Lm. .. In addition, in the description of Φn, Ln, Φm, and Lm in FIG. 7D, the lengths of the flat surface portions forming the corner portions are all within the range of 3 mm to 8 mm (all are regions A), and among the three laminated bodies, It refers to values such as Φn, Ln, Φm, and Lm when the relationship between the outermost laminated body in the radial direction and the laminated body located in the middle in the radial direction is paid attention to. However, the present embodiment is not limited to this, and the length of a part of the flat surface portion forming the corner portion can be less than 3 mm or more than 8 mm within the range satisfying the above formula (1). ..

3. 3. Directional electrical steel sheet As described above, in the grain-oriented electrical steel sheet used in the present invention, the grain steel sheet is a steel sheet in which the orientation of the crystal grains in the grain steel sheet is highly integrated in the {110} <001> orientation. It has excellent magnetic properties in the rolling direction.
In the present invention, a known grain-oriented electrical steel sheet can be used as the mother steel sheet. Hereinafter, an example of a preferable mother steel plate will be described.

The chemical composition of the base steel sheet is mass%, contains Si: 2.0% to 7.0%, and the balance is Fe. This chemical composition is for controlling the crystal orientation to a Goss texture integrated in the {110} <001> orientation and ensuring good magnetic properties. The other elements are not particularly limited, and it is permissible to replace them with Fe and contain known elements in a known range. The typical content range of typical elements is as follows.
C: 0 to 0.0050%,
Mn: 0-1.0%,
S: 0 to 0.0150%,
Se: 0 to 0.0150%,
Al: 0 to 0.0650%,
N: 0 to 0.0050%,
Cu: 0 to 0.40%,
Bi: 0 to 0.010%,
B: 0 to 0.080%,
P: 0 to 0.50%,
Ti: 0 to 0.0150%,
Sn: 0 to 0.10%,
Sb: 0 to 0.10%,
Cr: 0 to 0.30%,
Ni: 0-1.0%,
Nb: 0 to 0.030%,
V: 0 to 0.030%,
Mo: 0 to 0.030%,
Ta: 0 to 0.030%,
W: 0 to 0.030%,
Since these selective elements may be contained according to the purpose, it is not necessary to limit the lower limit value, and it is not necessary to substantially contain them. Further, even if these selective elements are contained as impurities, the effect of the present invention is not impaired. Impurities refer to elements that are unintentionally contained, and mean elements that are mixed from ore, scrap, or the manufacturing environment as raw materials when the base steel sheet is industrially manufactured.

The chemical composition of the mother steel sheet may be measured by a general analysis method for steel. For example, the chemical composition of the mother steel sheet may be measured using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectroscopy). Specifically, for example, a 35 mm square test piece is obtained from the center position of the mother steel plate after the coating is removed, and the conditions are based on a calibration curve prepared in advance by Shimadzu ICPS-8100 or the like (measuring device). It can be identified by measuring. In addition, C and S may be measured by using the combustion-infrared absorption method, and N may be measured by using the inert gas melting-thermal conductivity method.

The above chemical composition is a component of grain-oriented electrical steel sheets. If the grain-oriented electrical steel sheet to be the measurement sample has a primary coating (glass coating, intermediate layer) made of oxides, an insulating coating, etc. on the surface, the chemical composition is measured after removing these.

4. Method for manufacturing grain-oriented electrical steel sheet The method for manufacturing grain steel is not particularly limited, and a conventionally known method for manufacturing grain-oriented electrical steel sheet can be appropriately selected. As a preferable specific example of the production method, for example, C is 0.04 to 0.1% by mass, and the other slabs having the chemical composition of the mother steel plate are heated to 1000 ° C. or higher and hot-rolled. If necessary, hot-rolled sheet is annealed, and then cold-rolled once or twice or more with intermediate annealing sandwiched between them to make a cold-rolled steel sheet. A method of decarburizing and annealing by heating to ~ 900 ° C., further annealing and annealing as necessary, applying an annealing separator, finishing annealing at about 1000 ° C., and forming an insulating film at about 900 ° C. is mentioned. Be done. Further, after that, painting or the like for adjusting the friction coefficient may be carried out.
Further, the effect of the present invention can be enjoyed even if the steel sheet is subjected to a process generally called "magnetic domain control" by a known method in the steel sheet manufacturing process.

5. Method for manufacturing a wound core The basic method for manufacturing a wound core according to the present invention is not particularly limited as long as the wound core according to the present invention can be manufactured. For example, the publicly known methods introduced as Patent Documents 5 to 8 in the background art. The method according to the winding iron core of No. may be applied. In particular, the method using AEM UNICORE's UNICORE (https://www.aemcores.com.au/technology/unicore/) manufacturing equipment can be said to be optimal.

Further, the obtained wound core body may be used as a wound core as it is, but may be further fixed with a known fastener such as a binding band or the like to be used as a wound core, if necessary.

The present invention is not limited to the above embodiment. The above-described embodiment is an example, and any one having substantially the same structure as the technical idea described in the claims of the present invention and having the same effect and effect is the present invention. Is included in the technical scope of.

Hereinafter, the technical contents of the present invention will be further described with reference to examples of the present invention. The conditions in the examples shown below are examples of conditions adopted for confirming the feasibility and effect of the present invention, and the present invention is not limited to these conditions. Further, the present invention can adopt various conditions as long as the gist of the present invention is not deviated and the object of the present invention is achieved.

Using the grain-oriented electrical steel sheet shown in Table 2 (referred to as "product plate" in Table 2) manufactured from the steelmaking components shown in Table 1, the iron core shown in Table 3 was prepared and the iron core characteristics were measured. Each iron core shown in Table 3 has four corners, all four corners have the same shape, and the details of the shape of each corner are shown in Table 3. Detailed manufacturing conditions and characteristics are shown in Tables 4 and 5.
The column of "steel grade" in Table 2 is displayed in the format of "alphabet + number" (for example, A1 and A2). Of these, the alphabet represents the steel grade of the slab (steel grade in Table 1) that is the source of the steel grade.
Further, in the column of "shape" in Table 3, A represents an invariant type and B represents a variable type. The invariant type means that one corner portion is composed of a specific bending angle. The variable type means that steel plates bent at different bending angles are mixed in one corner portion. Further, in the bent steel sheet laminating pattern in Table 3, A represents a ΔL = T · tan θ pattern (FIG. 7A), and B represents a ΔL = 0 pattern (FIG. 7B).

(Directional magnetic steel sheet)
The magnetic properties of grain-oriented electrical steel sheets were measured based on the single sheet magnetic property test method (Single Sheet Tester: SST) specified in JIS C 2556: 2015.
As magnetic characteristics, the magnetic flux density B8 (T) in the rolling direction of the steel sheet when excited at 800 A / m, and the iron loss at an AC frequency of 50 Hz and an exciting magnetic flux density of 1.7 T were measured. The magnetic properties as well as the chemical composition are shown in Tables 1 and 2.
(Iron core)
Using each steel plate as a material, iron cores a1 to h having the shapes shown in Table 3 were manufactured. Here, FIG. 8 is used as a reference diagram, and the parameters used as the values defining the core shape in Table 3 will be described. L1'is the length of the inner surface side plane portion in one direction (X direction) in the side view in the winding axis direction (Y direction) of the wound iron core, and L2'is the other direction (Z direction) perpendicular to this. ) Is the length of the inner surface side plane portion. L3 is the laminated thickness of the wound iron core, L4 is the width of the laminated steel plate of the wound iron core, and the value of the distance L5 between the innermost plane portions is the length of the flat surface portion between the bent portions of the innermost peripheral portion. That is, the length of the flat surface portion between the bent portions is the same regardless of whether the number of bent portions in the corner portion is two or more. Further, as the value of L5 when the number of bent portions is 2 or more, the length of the flat surface portion between the bent portions of the innermost steel plate corresponding to _L0 in FIG. 7A is used. Further, in the core h as shown in FIG. 7D, the value of _L0 between the bent portions on the innermost circumference is set as the value of L5. r is the radius of curvature on the inner surface side of the bent portion on the inner surface side of the wound core, and φ is the bending angle of the bent portion of the wound core.

(Efficiency of iron core)
The no-load loss was obtained for the iron core made of each steel sheet, and the building factor (BF) was obtained by taking the ratio with the magnetic characteristics of the material steel sheets shown in Table 1. The results are shown in Tables 4 and 5. In this example, those having a BF of 1.12 or less were regarded as acceptable.
Example No. 1 to No. Section 6 shows the effect when the number of stacked sheets is reduced in order to increase the ratio of the length of the flat surface portion between the bent portions to 4 mm to 8 mm. Example No. 1a to No. In 6a, the effect when the length of the flat surface portion between the bent portions is maintained at a high ratio of 4 mm to 8 mm without reducing the number of stacked portions is shown. Example No. 7-No. Reference numeral 12 shows the effect when the number of bent portions is increased to increase the proportion of the steel plate having the flat portion satisfying L = 3 to 8 mm. Example No. 13-No. Section 21 shows the effect when the length of the flat surface portion between the bent portions is changed to 2 mm to 9 mm. Example No. 22-No. In No. 28, the effect when the number of Ma is changed by changing the method of laminating the steel sheets in the middle without changing the number of bent portions is shown. Example No. 29-No. In No. 40, the effect when the shape of the core is changed is shown.

From the results of Tables 4 and 5, the directional electromagnetic steel plates are laminated in the plate thickness direction and have a substantially rectangular shape in the side view. The directional electromagnetic steel plates have a flat surface portion and a bent portion in the longitudinal direction. Are alternately continuous, the radius of curvature r on the inner surface side in the side view of the bent portion is 3 mm or less, the directional electromagnetic steel plate contains% by mass, Si: 2.0 to 7.0%, and the balance. Has a chemical composition consisting of Fe and impurities, has an texture oriented in the Goss direction, and is 10 ° or more and 80 ° or less in the circumferential direction of the wound core in the side view of the laminated directional electromagnetic steel plate. When the region where the bent portion having an angle and the flat portion having a length of 3 to 8 mm are alternately continuous is defined as the region A, and the number of directional electromagnetic steel plates in which the region A exists is Ma, the total number of laminated sheets is defined as Mtotal.
Ma / Mtotal ≧ 0.30 ・ ・ ・ ・ ・ (1)
It has been clarified that the wound core of the present invention, which is characterized by satisfying the above, has high efficiency.

1 Electrical steel sheet 1a Electrical steel sheet before forming a bent part 2 Laminated structure 3 Corner part 4 Flat part 5 Bent part 6 Joint part 7 Recessed part 10 Rolled iron core body (rolled iron core)

Claims (5)

It is a wound steel core in which grain-oriented electrical steel sheets are laminated in the plate thickness direction and is substantially rectangular in side view.
In the grain-oriented electrical steel sheet, flat surfaces and bent portions are alternately continuous in the longitudinal direction.
The radius of curvature r on the inner surface side in the side view of the bent portion is 3 mm or less, and is
The grain-oriented electrical steel sheet is by mass%,
Si: contains 2.0 to 7.0%, has a chemical composition with the balance consisting of Fe and impurities, and has a chemical composition.
In the side view of grain-oriented electrical steel sheets having a texture oriented in the Goss direction and laminated.
Area A is a region where bent portions having an angle of 10 ° or more and 80 ° or less and flat portions having a length of 3 to 8 mm are alternately continuous in the circumferential direction of the wound steel core, and the grain-oriented electrical steel sheet in which this region A exists. When the number of sheets is Ma, the total number of laminated sheets is set to Mtotal.
Ma / Mtotal ≧ 0.30 ・ ・ ・ ・ ・ (1)
A winding iron core characterized by satisfying. Of the winding iron cores of claim 1,
The regional portions A of the grain-oriented electrical steel sheets having the same circumferential length but different from each other are laminated with the planar portions in parallel and continuously.
The bending angle of the bent portion of the region A is Φ, the thickness of the region in which the flat portions are laminated in parallel and continuously is H, and the thickness of the steel plate laminated in the region is H. When the stacking thickness is Lx,
Lx / H / cosΦ: 0.97 to 1.03 ・ ・ ・ ・ ・ (2)
A winding iron core characterized by satisfying. Of the winding iron cores of claim 1,
At least two of the regions A are laminated and arranged in parallel with the plane portion of each of the regions A.
Let Φ be the bending angle of the bent portion constituting the region A.
Let Ln be the length of the plane portion arranged on the inner surface side of the iron core in the circumferential direction.
Let Lm be the length of the plane portion arranged on the outer surface side of the iron core in the circumferential direction.
Further, when the distance between the two plane portions is Lh,
Lm <Ln ・ ・ ・ ・ ・ (3)
Lh / {(Ln-Lm) / 2} / tanΦ> 0.98 ・ ・ ・ ・ ・ (4)
A winding iron core characterized by satisfying. Of the winding iron cores of claim 1,
At least two of the regions A are laminated in a non-parallel manner with at least one of the plane portions of each of the regions A.
For the region A arranged on the inner surface side of the iron core, the bending angle of the bent portion is Φn, the number of the bent portions is Rn, and the average length of the flat surface portion in the circumferential direction is Ln.
When the bending angle of the bent portion is Φm, the number of the bent portions is Rm, and the average length of the flat surface portion in the circumferential direction is Lm for the region A arranged on the outer surface side of the iron core.
Φm <Φn ・ ・ ・ ・ ・ (5)
Rm> Rn ・ ・ ・ ・ ・ (6)
Lm <Ln ・ ・ ・ ・ ・ (7)
A winding iron core characterized by satisfying. The wound iron core according to any one of claims 1 to 4, wherein the laminated thickness L3 of the core is 16 mm or more.

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