JP2018157142A - Selection method of grain-oriented electromagnetic steel sheet and manufacturing method of wound core - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a wound core with a low iron loss.SOLUTION: A selection method of one group grain-oriented electromagnetic steel sheet used as a material of a wound core, includes: a step of preparing the one group grain-oriented electromagnetic steel sheet having a different flux density Bvalue when intensity H of a magnetic field is 800A/m while having the same iron loss; a step of measuring the Bvalue from an Epstein test for the one group grain-oriented electromagnetic steel sheet; and a step of selecting the grain-oriented electromagnetic steel sheet having the Bvalue which is a predetermined value or larger set from a range of the Bvalue of the one group grain-oriented electromagnetic steel sheet obtained by measuring from the one group grain-oriented electromagnetic steel sheet as the material of the wound core including at least two or more joint parts within one circumference.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a method for sorting grain-oriented electrical steel sheets and a method for manufacturing a wound iron core using the sorted grain-oriented electrical steel sheets.

  Iron cores are widely used as magnetic cores for transformers, reactors, noise filters, and the like. Reduction of the iron loss generated in the iron core is one of the important issues from the standpoint of high efficiency, and conventionally, studies on the reduction of iron loss have been made from various viewpoints.

  As one of the methods for manufacturing a wound core, for example, a method is widely known in which a steel sheet is wound into a cylindrical shape, a corner portion is pressed, formed into a substantially rectangular shape, and then annealed for annealing and shape retention. It has been. In the case of this manufacturing method, the radius of curvature of the corner varies depending on the dimensions of the wound core, but the radius of curvature is a relatively large and gently curved surface of approximately 4 mm or more.

As another method of manufacturing a wound core, a method of laminating electromagnetic steel sheets to form a wound core by bending a portion that becomes a corner portion of a wound core of an electromagnetic steel sheet in advance and superimposing the bent electromagnetic steel sheets Is being considered.
According to the manufacturing method, the pressing step is unnecessary, and the shape is maintained because the electromagnetic steel sheet is bent, and the shape maintaining by the annealing step is not an essential step, and therefore the manufacturing is easy. There are benefits. In this manufacturing method, since a magnetic steel sheet is bent, a relatively small bent portion having a radius of curvature of about 1 mm to 3 mm is formed in the processed portion.

  In addition, a normal wound iron core has one joint, but a wound iron core having two joints is also manufactured. Since there are two joints, it is possible to reduce the time for lacing compared to a normal core with one joint. In addition, there is an advantage that distortion is hardly introduced. However, since there are two joints, the iron loss is larger than a wound core with one joint.

As a wound iron core manufactured by a manufacturing method including bending, for example, in Patent Document 1, a plurality of magnetic steel plates with different lengths that are bent in an annular shape are overlapped in the outer circumferential direction, and each magnetic steel plate is opposed to each other. A structure of a wound iron core is disclosed in which the end surfaces are evenly displaced by a predetermined dimension in the stacking direction and the joints are stepped.
Patent Document 2 discloses a jig for easily manufacturing a wound iron core obtained by bending a processed portion and a manufacturing method thereof.

Utility Model Registration No. 3081863 JP 2005-286169 A

The researchers obtained knowledge that the core loss of the wound iron core may increase as the number of joints in one turn increases.
The present disclosure has been made in view of the above circumstances, and a method for selecting a directional electrical steel sheet for manufacturing a wound iron core having a low iron loss, and a method for manufacturing a wound iron core using the selected directional electromagnetic steel sheet. The purpose is to provide.

The method for sorting grain-oriented electrical steel sheets of the present disclosure is as follows.
A method for selecting a group of grain-oriented electrical steel sheets used as a material for a wound core,
Same iron loss, and a step of intensity H of the magnetic field to prepare the set of oriented electrical _steel sheet ₈ value magnetic flux density B is different when the 800A / m,
For the set of oriented electrical steel sheet, and measuring the B ₈ value by Epstein test,
Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value greater than a predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by Selecting as a wound core material having at least two joints in one turn;
It is characterized by having.

In the method for sorting grain-oriented electrical steel sheets of the present disclosure,
Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value less than the predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by , The joint may be selected as a material for a wound core having less than two locations.

In the method for sorting grain-oriented electrical steel sheets of the present disclosure,
The wound core includes a substantially rectangular wound core body in a side view,
The wound core body is composed of the grain-oriented electrical steel sheet, and planar portions and corner portions are alternately continued in the longitudinal direction, and an angle formed between two planar portions adjacent to each corner portion is 90 °. The grain-oriented electrical steel sheets may be stacked in the thickness direction, and may have a substantially rectangular laminated structure in a side view.

In the method for sorting grain-oriented electrical steel sheets of the present disclosure,
In the wound iron core having two or more joint portions, each corner portion has one or more bent portions having a curved shape in a side view of the grain-oriented electrical steel sheet, and one corner The total bending angle of each bent portion existing in the portion may be 90 °.

The manufacturing method of the wound core of the present disclosure is as follows:
Iron loss identical, and the steps of the strength H of the magnetic field to prepare a group of grain-oriented electrical _steel sheet ₈ value magnetic flux density B is different when the 800A / m,
For the set of oriented electrical steel sheet, and measuring the B ₈ value by Epstein test,
Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value greater than a predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by Selecting as a wound core material having at least two joints in one turn;
Creating the wound iron core using the selected grain-oriented electrical steel sheet;
It is characterized by having.

In the manufacturing method of the wound core of the present disclosure,
Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value less than the predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by , The joint may be selected as a material for a wound core having less than two locations.

In the manufacturing method of the wound core of the present disclosure,
The wound core includes a substantially rectangular wound core body in a side view,
The wound core body is composed of the grain-oriented electrical steel sheet, and planar portions and corner portions are alternately continued in the longitudinal direction, and an angle formed between two planar portions adjacent to each corner portion is 90 °. The grain-oriented electrical steel sheets may be stacked in the thickness direction, and may have a substantially rectangular laminated structure in a side view.

In the manufacturing method of the wound core of the present disclosure,
In the wound iron core having two or more joint portions, each corner portion has one or more bent portions having a curved shape in a side view of the grain-oriented electrical steel sheet, and one corner The total bending angle of each bent portion existing in the portion may be 90 °.

According to the present disclosure, the iron loss is the same, and, a grain-oriented electrical steel sheet obtained by selecting a low-oriented electrical steel sheet relatively B ₈ values from a group of grain-oriented electrical _steel sheet ₈ value B are different By using it as a material for a wound core having less than two joints, it is possible to manufacture a wound core group with a lower iron loss using the group of directional electrical steel sheets than when not selected. .

FIG. 1 is a perspective view schematically showing one embodiment of a wound iron core. FIG. 2 is a side view of the wound iron core shown in the embodiment of FIG. FIG. 3 is a side view schematically showing another embodiment of the wound core. FIG. 4 is a side view schematically showing another embodiment of the wound core. FIG. 5 is an enlarged side view of the vicinity of a corner portion in the embodiment of FIG. FIG. 6 is an enlarged side view of the vicinity of a corner portion in the embodiment of FIG. FIG. 7 is an enlarged side view of the vicinity of a corner portion in the embodiment of FIG. FIG. 8 is a side view schematically showing an example of the grain-oriented electrical steel sheet. FIG. 9 is a side view schematically showing another example of the grain-oriented electrical steel sheet. FIG. 10 is a side view schematically showing an example of a bent portion of a grain-oriented electrical steel sheet. FIG. 11 is a schematic diagram illustrating an example of a bending method in the method of manufacturing a wound core. FIG. 12 is a schematic diagram showing dimensions of the wound core used in the reference experiment example.

1. Screening method for grain-oriented electrical steel sheet
A method for selecting a group of grain-oriented electrical steel sheets used as a material for a wound core,
Same iron loss, and a step of intensity H of the magnetic field to prepare the set of oriented electrical _steel sheet ₈ value magnetic flux density B is different when the 800A / m,
For the set of oriented electrical steel sheet, and measuring the B ₈ value by Epstein test,
Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value greater than a predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by Selecting as a wound core material having at least two joints in one turn;
It is characterized by having.

As used in this disclosure, the shape and geometric conditions and the degree thereof are specified. For example, terms such as “parallel”, “vertical”, “same”, “right angle”, and values of length and angle are strictly Without being bound by any meaning, it should be interpreted including the extent to which similar functions can be expected.
In the wound core of the present disclosure, a wound core that owns one joint during one turn and does not have a bent portion is referred to as a tranco core, and has one bent portion and has a bent portion during one turn. In some cases, the iron core is referred to as a unicore, and the wound core having two joints and having a bent portion in one turn is referred to as a duocore.

The wound iron core is manufactured by shearing the hoop and winding it into a donut shape, then pressing the corner portion, forming it into a rectangular shape, annealing, and removing the strain and maintaining the shape.
And the junction part used as the butt | matching part of a steel plate is formed.
In order to suppress deterioration of iron loss due to an increase in magnetic resistance at the butt portion, this butt is arranged in a step shape.
Ideally, it is desirable to set the gap length of this butt to 0. However, if an error occurs in the steel plate length due to shearing and the core circumference becomes longer than the design value due to deviations in the steel plate thickness, the gap length is The outer side of the winding thickness increases. There is a problem that the iron loss of the wound iron core deteriorates due to the existence of the gap length. In particular, a wound iron core having two or more joints has a problem that iron loss deterioration due to the gap length is remarkable.

On the other hand, the iron loss is a group of oriented electrical steel sheet are the same, there is a situation that the orientation integration degree of the oriented electrical steel sheet ₍₈ value B) are different.
The present investigators, (A) Tran cocoa, (B) Yunikoa, (C) using different materials B ₈ value on the same iron loss value in each type of the three types of wound cores of Deyuokoa, building factor (BF ) Was evaluated.
Use a result, when manufacturing wound cores (Deyuokoa etc.) having at least two or more joints in one round, if the iron loss identical, relatively B ₈ value is high oriented electrical steel sheet who There are, than using relatively B ₈ value less oriented electrical steel sheets was also found that the large effect of suppressing the iron loss deterioration due to the gap length (see reference experiment).
On the other hand, when manufacturing a wound core having less than two joints in one turn (for example, unicore, trancocore, etc.) by the researches of the present researchers, a wound core having two or more joints as described above. It was found that the effect of iron loss deterioration due to fluctuations in the B ₈ value was small compared to.
Although the details of this cause are unknown, it was thought that the in-plane eddy current loss would increase because the magnetic flux moved to the steel plates above and below the gap from the behavior of the magnetic flux at the joint (crossing the magnetic flux). but researchers have found that the increase in iron loss due to crossover of the magnetic flux affecting the B ₈ value of the grain-oriented electrical steel sheet. Since the B ₈ value is high, the magnetic permeability is high and the magnetic resistance is small. Therefore, it is presumed that the transition of the magnetic flux becomes smooth and the increase in the in-plane eddy current loss becomes gentle. Furthermore, the number of the junctions increases, so that the region where the magnetic flux passes increases. It is presumed that the above effect has increased as this area increases.
Therefore, according to the present disclosure, when manufacturing a wound core having at least two joints in one turn in which the influence of iron loss deterioration due to fluctuations in the B ₈ value is large, the iron loss is the same, and B oriented electrical steel sheet obtained by selecting a high-oriented electrical steel sheet relatively B ₈ value from among _eight values are different family oriented electrical steel sheet, the material of the wound core to which the joint is more than two As a result, it is possible to manufacture a wound core group with low iron loss.
Further, according to the present disclosure, in addition to the above, the iron loss is the same, and, ₈ value B by selecting a low-oriented electrical steel sheet relatively B ₈ values from the different family oriented electrical steel sheets obtained and the directional electromagnetic steel plates, at least two or more windings is less affected the junction is less than two degradation iron loss due to changes in ₈ values B compared to wound core having a joint in one round By using it as a material for the iron core, a wound iron core group having a low iron loss can be manufactured from the group of grain-oriented electrical steel sheets.

The grain-oriented electrical steel sheet sorting method of the present disclosure includes at least (1) a preparation process, (2) a measurement process, and (3) a sorting process.
Hereinafter, each process is demonstrated in order.

(1) Preparation step preparation process, the iron loss identical, and a step of intensity H of the magnetic field to prepare the set of oriented electrical _steel sheet ₈ value magnetic flux density B is different when the 800A / m.
The ₈ values B herein, the strength H of the magnetic field obtained by Epstein test is the magnetic flux density in the 800A / m, is a value indicative of the orientation integration degree.

In general, a grain-oriented electrical steel sheet is a steel sheet in which the orientation of crystal grains in the steel sheet is highly accumulated in the {110} <001> orientation and the easy axis of magnetization is aligned in the longitudinal direction. Since the easy magnetization axis is aligned in the longitudinal direction, it refers to an electrical steel sheet having the characteristics of low iron loss and excellent magnetism.
In the present disclosure, the grain-oriented electrical steel sheet has at least a base steel plate, and may have a coating on the surface of the base steel plate as necessary. Examples of the coating include a glass coating. Hereinafter, each structure of the grain-oriented electrical steel sheet will be described.

The base steel plate is a steel plate in which the orientation of crystal grains in the base steel plate is highly accumulated in the {110} <001> orientation, and has excellent magnetic properties in the rolling direction.
In the present disclosure, the mother steel plate is not particularly limited, and can be appropriately selected from those known as grain-oriented electrical steel plates. Hereinafter, although an example of a preferable mother steel plate will be described, in the present disclosure, the mother steel plate is not limited to the following.

The chemical composition of the mother steel plate is not particularly limited. For example, in mass%, Si: 0.8% to 7%, C: higher than 0% and 0.085% or less, acid-soluble Al: 0 % To 0.065%, N: 0% to 0.012%, Mn: 0% to 1%, Cr: 0% to 0.3%, Cu: 0% to 0.4%, P: 0% to 0.5%, Sn: 0% to 0.3%, Sb: 0% to 0.3%, Ni: 0% to 1%, S: 0% to 0.015%, Se: 0% to 0. It is preferable that 015% is contained and the balance consists of Fe and impurities. The chemical composition of the mother steel plate is a preferable chemical component for controlling the Goss texture in which the crystal orientation is accumulated in the {110} <001> orientation. Of the elements in the mother steel plate, Si and C are basic elements, and acid-soluble Al, N, Mn, Cr, Cu, P, Sn, Sb, Ni, S, and Se are selective elements. Since these selective elements may be contained according to the purpose, there is no need to limit the lower limit value, and it may not be contained substantially. Moreover, even if these selective elements are contained as inevitable impurities, the effect of the present disclosure is not impaired. In the mother steel plate, the balance of the basic element and the selective element is composed of Fe and inevitable impurities.
In the present disclosure, “inevitable impurities” refers to elements that are inevitably mixed from ores, scraps, or production environments as raw materials when the mother steel plate is industrially produced.
In general, grain oriented electrical steel sheets undergo purification annealing during secondary recrystallization. In the purification annealing, the inhibitor forming elements are discharged out of the system. In particular, for N and S, the decrease in the concentration is remarkable, and it becomes 50 ppm or less. Under normal purification annealing conditions, 9 ppm or less, further 6 ppm or less. If the purification annealing is sufficiently performed, it reaches a level that cannot be detected by general analysis (1 ppm or less).
The chemical composition of the mother steel plate may be measured by a general steel analysis method. For example, the chemical composition of the mother steel plate may be measured using ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry). Specifically, for example, a 35 mm square test piece is obtained from the center position of the mother steel plate after removal of the coating, and is based on a calibration curve prepared in advance by Shimadzu ICPS-8100 or the like (measurement device). It can be specified by measuring. C and S may be measured using a combustion-infrared absorption method, and N may be measured using an inert gas melting-thermal conductivity method.
In addition, the chemical component of the base steel plate is a component obtained by analyzing a component of a steel plate obtained by removing a glass coating and a coating containing phosphorus described below from a grain-oriented electrical steel plate by a method described below.

The manufacturing method of a base steel plate is not specifically limited, The manufacturing method of a conventionally well-known grain-oriented electrical steel plate can be selected suitably. As a preferable specific example of the production method, for example, after C is 0.04 to 0.1% by mass, and the others are hot-rolled by heating a slab having the chemical composition of the base steel plate to 1000 ° C. or higher. Then, if necessary, hot-rolled sheet annealing is performed, and then cold-rolled steel sheet is formed by cold rolling at least once with intermediate or intermediate annealing, and the cold-rolled steel sheet is 700 in a wet hydrogen-inert gas atmosphere, for example. Examples include a method of heating to ˜900 ° C., decarburizing annealing, further nitriding annealing as necessary, and finish annealing at about 1000 ° C.
In the present disclosure, the thickness of the base steel plate is not particularly limited, but is preferably 0.1 mm or more and 0.5 mm or less, and more preferably 0.15 mm or more and 0.40 mm or less.

In the present disclosure, the grain-oriented electrical steel sheet may have a coating on the surface as long as the effects of the present disclosure are not impaired. Examples of such a coating include a glass coating formed on a mother steel plate. The glass coating includes, for example, one or more oxides selected from forsterite (Mg ₂ SiO ₄ ), spinel (MgAl ₂ O ₄ ), and cordierite (Mg ₂ Al ₄ Si ₅ O ₁₆ ). A film is mentioned.

The method for forming the glass coating is not particularly limited, and can be appropriately selected from known methods. For example, in a specific example of the manufacturing method of the base steel sheet, after the cold separator steel sheet is coated with an annealing separator containing one or more selected from magnesia (MgO) and alumina (Al ₂ O ₃ ), the finishing is performed. A method of annealing is mentioned. In addition, the said annealing separator has the effect which suppresses the sticking of the steel plates at the time of finish annealing. For example, when finish annealing is performed by applying the annealing separator containing magnesia, a glass coating containing forsterite (Mg ₂ SiO ₄ ) is formed on the surface of the base steel plate by reacting with silica contained in the base steel plate. The
In the present disclosure, the thickness of the glass coating is not particularly limited, but is preferably 0.5 μm or more and 3 μm or less.

  The plate thickness of the grain-oriented electrical steel sheet used in the present disclosure is not particularly limited, and may be appropriately selected according to the use etc., but is usually within a range of 0.15 mm to 0.35 mm, preferably The range is from 0.18 mm to 0.23 mm.

(2) measuring step measuring step, for the set of oriented electrical steel sheet, a step of measuring the B ₈ value by Epstein test.
The B ₈ value of the grain-oriented electrical steel sheet can be determined by a conventionally known method, for example, by the exciting current method in the method for measuring the magnetic properties of the electromagnetic steel strip by the Epstein tester described in JIS C 2550-1. Can do.
In addition, about the collection of a sample, the sample of arbitrary places may be taken from the full width (for example, 1000 mm) of a grain-oriented electrical steel sheet, and the sample of several places may be taken by a fixed width interval.
The timing of the measurement is not particularly limited, and can be set as appropriate according to the production amount of the wound core and the like. Further, even oriented electrical steel sheet having the same iron loss, ₈ value B are different (e.g., has a width of about 1.89～1.93T) on the assumption that, may be measured.

(3) sorting step sorting process, said one of a group of grain-oriented electrical steel sheet, the above predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by B _This is a step of selecting a grain-oriented electrical steel sheet having _eight values as a material for a wound core having at least two joints in one turn.
Further, the one of a group of directional electromagnetic steel plates, oriented electrical having a B ₈ value less than the predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by A steel plate may be selected as a material for a wound core having less than two joints.
In the present disclosure, the predetermined value may be set as appropriate based on the B ₈ value measured.
Further, in the present disclosure, a wound iron core having at least two or more joints during one turn may normally have at least one or more bent parts during one turn.
On the other hand, in the present disclosure, a wound iron core having less than two joint portions in one turn may have a bent portion or may not have a joint portion and may have one. It may be.
The selection of materials, may if we use a high material having B ₈ values in descending wound cores of bonded parts in sequence, the "predetermined value set from the range of ₈ values B", the one orbiting Are determined based on the amount of the wound core material having at least two joints, the amount of the wound core material having less than two joints, and the like. Therefore, not the fixed value in relation to a numerical value of B _8. If the joints have the same number of wound cores, it is not necessary to select the material.

A wound core manufactured from the selected material has a substantially rectangular wound core body in a side view, and the wound core body is made of the directional electromagnetic steel sheet, and flat portions and corner portions are alternately arranged in the longitudinal direction. The directional electrical steel sheets having an angle of 90 ° formed by two adjacent flat portions at each corner portion are stacked in the thickness direction, and have a substantially rectangular laminated structure in a side view. May be.
Further, in the wound iron core having two or more joint portions manufactured from the selected material, each corner portion has one or more bent portions having a curved shape in a side view of the grain-oriented electrical steel sheet. In addition, the sum of the bending angles of the bent portions existing in one corner portion may be 90 °.
Since the shape of the wound core and the manufacturing method will be described later, description thereof is omitted here.

FIG. 8 is a diagram schematically showing an example of a grain-oriented electrical steel sheet used as a material for a wound core having one joint and a bent portion during one turn.
FIG. 9 is a diagram schematically showing an example of a grain-oriented electrical steel sheet used as a material for a wound iron core having two joint portions and a bent portion during one turn.
As shown in the examples of FIGS. 8 and 9, the grain-oriented electrical steel sheet that can be used for a wound iron core having one or more joints and a bent part during one turn, is bent, It has a corner portion 3 composed of one or two or more bent portions 5 corresponding to the corner portion of the wound iron core, and a plane portion 4, and is substantially interposed through one or more joint portions 6 during one turn. A rectangular ring may be formed.
As shown in the example of FIG. 8, one grain-oriented electrical steel sheet may constitute one layer of the wound core body via one joint 6, and is shown in the example of FIG. 9. Thus, one directional electromagnetic steel sheet constitutes about half the circumference of the wound iron core, and two directional electromagnetic steel sheets constitute one layer of the wound iron core body through two joints 6. Also good.
Further, as another example of the grain-oriented electrical steel sheet used as the material for the wound core, when two grain-oriented electrical steel sheets constitute one layer of the wound core body, a bent body corresponding to three sides of a substantially rectangular core And a substantially rectangular ring may be formed by combining straight steel plates corresponding to the remaining one side (side view is straight). Thus, when two or more grain-oriented electrical steel sheets constitute one layer of the wound core body, a bent steel sheet and a straight steel plate (in a side view in a straight line) may be combined.
Furthermore, as an example of a grain-oriented electrical steel sheet used as a material for a wound core without a joint, a directional electrical steel sheet having a length equal to or longer than two layers of the wound core body is bent to form a substantially rectangular ring. A bent body that is continuous for two or more turns may be formed and stacked in the thickness direction.
In any case, in order to prevent a gap from being generated between two adjacent layers at the time of manufacturing the wound core, in the adjacent two-layer directional electromagnetic steel sheet, the outer peripheral length of the flat portion 4 of the directional electromagnetic steel sheet disposed inside The length of the steel plate and the position of the bent portion are adjusted so that the inner peripheral length of the flat portion 4 of the grain-oriented electrical steel plate disposed on the outside is equal.

2. The manufacturing method of a wound iron core of this indication
Iron loss identical, and the steps of the strength H of the magnetic field to prepare a group of grain-oriented electrical _steel sheet ₈ value magnetic flux density B is different when the 800A / m,
For the set of oriented electrical steel sheet, and measuring the B ₈ value by Epstein test,
Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value greater than a predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by Selecting as a wound core material having at least two joints in one turn;
Creating the wound iron core using the selected grain-oriented electrical steel sheet;
It is characterized by having.

The method for manufacturing a wound core of the present disclosure includes at least (1) a preparation step, (2) a measurement step, (3) a selection step, and (4) a winding core creation step.
Since the steps (1) to (3) are the same as the above-described “1. Method for selecting grain-oriented electrical steel sheets”, description thereof is omitted here.

(4) Winding core creation step The winding core creation step is a step of creating the wound core using the selected grain-oriented electrical steel sheet.

First, the shape of the wound core of the present disclosure will be described. FIG. 1 is a perspective view schematically showing one embodiment of a wound iron core. FIG. 2 is a side view of the wound iron core shown in the embodiment of FIG. 3 and 4 are side views schematically showing another embodiment of the wound core.
In the present disclosure, the side view refers to viewing in the width direction (Y-axis direction in FIG. 1) of the long directional electromagnetic steel sheet constituting the wound iron core, and the side view is visually recognized from the side view. FIG. 2 is a diagram (a diagram in the Y-axis direction in FIG. 1) showing the shape of

  The wound iron core of the present disclosure includes a substantially rectangular wound core body in a side view. In the wound core body, directional electromagnetic steel sheets are stacked in the thickness direction, and have a substantially rectangular laminated structure in a side view. The wound core body may be used as a wound core as it is, or may be provided with a known fastening tool such as a binding band in order to fix the wound core as necessary.

  In the present disclosure, the core length of the wound core body is not particularly limited, but is preferably 1.5 m or more and more preferably 1.7 m or more because it exhibits excellent low iron loss characteristics. In the present disclosure, the core length of the wound core body refers to the circumference at the center point in the stacking direction of the wound core body as viewed from the side.

  Since the core loss obtained by the manufacturing method of the present disclosure has reduced iron loss, it can be suitably used for any conventionally known applications such as a magnetic core such as a transformer, a reactor, and a noise filter.

As shown in FIGS. 1 and 2, in the wound core body 10, the plane portions 4 and the corner portions 3 are alternately continued in the longitudinal direction, and the angle formed between the two plane portions 4 adjacent to each other at each corner portion 3 is 90 °. The grain-oriented electrical steel sheet 1 that is ° includes a portion stacked in the thickness direction, and has a substantially rectangular laminated structure 2 in a side view.
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 bent portion existing in one corner portion is the same. The total is 90 °.
The embodiment shown in 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 there are three bent portions 5 in one corner portion 3.
Further, the embodiment of FIG. 4 is a case where one corner portion 3 is formed by one bent portion 5.

5 to 7 are enlarged side views of the vicinity of the corner portion in the embodiment of FIGS.
As shown in the examples of FIGS. 5 and 6, when two or more bent portions are provided at one corner portion, the first portion is formed on the linear portion representing the first flat portion of the grain-oriented electrical steel sheet. The bent portion (curved portion) is continuous, and beyond that, the bent portion (curved portion) and the straight portion are alternately continued, such as a straight portion, a second bent portion (curved portion), and another straight portion. A shape in which the second flat portion of the grain-oriented electrical steel sheet is connected to the last bent portion (curved portion) in the corner portion, and adjacent to the first flat portion via the corner portion. Have

  In the example of FIG. 5, a region from the line segment A-A ′ to the line segment B-B ′ is a corner portion 3. Point A is an end point on the flat portion 4a side in the bent portion 5a of the directional electromagnetic steel sheet 1a arranged on the innermost side of the wound iron core 10, and the point A ′ passes through the point A and is a plate surface of the directional electromagnetic steel sheet 1a. The intersection of the straight line perpendicular to the outermost surface of the wound core body 10. Similarly, the point B is an end point on the flat portion 4b side in the bent portion 5b of the directional electromagnetic steel sheet 1a disposed on the innermost side of the wound iron core 10, and the point B ′ passes through the point B and the directional electromagnetic steel sheet 1a. This is the intersection of a straight line perpendicular to the plate surface and the outermost surface of the wound core body 10. In FIG. 5, an angle formed by two plane portions 4 a and 4 b adjacent to each other via the corner portion 3 is θ, and in the present disclosure, the angle is 90 °. The bending angle φ of the bent portion will be described later. In FIG. 5, φ1 + φ2 is 90 °.

  Next, an example having three or more bent portions 5 in the corner portion 3 will be described. FIG. 6 is an enlarged view of the vicinity of a corner portion in the embodiment of FIG. Also in FIG. 6, the area from the line segment A-A ′ to the line segment B-B ′ is defined as the corner portion 3 as in FIG. 5. In FIG. 6, point A is an end point on the flat portion 4a side of the bent portion 5a closest to the flat portion 4a, and point B is an end point on the flat portion 4b side of the bent portion 5b closest to the flat portion 4b. When there are three or more bent portions, a straight portion exists between the bent portions. Which flat portion constitutes the plane portion 4 may be determined in consideration of the angle θ formed by two plane portions adjacent to each other via the corner portion being 90 °. The bend 5 adjacent to the is determined. In the example of FIG. 6, φ1 + φ2 + φ3 is 90 °, and in general, when there are n bent portions in the corner portion, φ1 + φ2 +... + Φn is 90 °.

  Next, the case where there is one bent portion 5 in the corner portion 3 will be described. FIG. 7 is an enlarged view of the vicinity of a corner portion in the embodiment of FIG. In FIG. 7 as well, similarly to FIGS. 5 and 6, the region from the line segment A-A ′ to the line segment B-B ′ is defined as the corner portion 3. In FIG. 7, a point A is an end point on the flat portion 4 a side of the bent portion 5, and a point B is an end point on the flat portion 4 b side of the bent portion 5. In the example of FIG. 7, φ1 is 90 °.

In the present disclosure, when the angle θ of the corner portion described above is 90 °, φ may be 90 ° or less. From the viewpoint of suppressing the generation of distortion due to deformation during processing and suppressing iron loss, φ may be 60 ° or less, or 45 ° or less. Therefore, the wound iron core obtained in the present disclosure may have two or more bent portions at one corner portion.
In the embodiment of FIG. 5 having two bent portions at one corner, for example, φ1 = 60 ° and φ2 = 30 °, or φ1 = 45 ° and φ2 = 45 ° from the viewpoint of reducing iron loss. Etc. In the embodiment of FIG. 6 having three bent portions at one corner portion, for example, φ1 = 30 °, φ2 = 30 °, and φ3 = 30 ° can be set from the viewpoint of reducing iron loss. Furthermore, since it is preferable that the bending angles are equal from the viewpoint of production efficiency, when there are two bent portions at one corner portion, φ1 = 45 ° and φ2 = 45 ° may be set. Further, in the embodiment of FIG. 6 having three bent portions at one corner, for example, φ1 = 30 °, φ2 = 30 °, and φ3 = 30 ° may be set from the viewpoint of reducing iron loss.

The bending portion 5 will be described in more detail with reference to FIG. FIG. 10 is a diagram schematically illustrating an example of a bent portion of a grain-oriented electrical steel sheet. The bending angle of the bent portion means a difference in angle generated between the straight portion on the rear side and the straight portion on the front side in the bending direction in the directional electromagnetic steel plate bent portion. The complementary angle of the angle formed by the two virtual lines Lb-longation 1 and Lb-longation 2 obtained by extending the straight line portions adjacent to both sides (point F and point G) of the curved line portion included in the line Lb representing the outer surface Expressed as φ.
The bending angle of each bending portion is 90 ° or less, and the total bending angle of all the bending portions existing in one corner portion is 90 °.

  In the present disclosure, the bent portion refers to a point D and a point E on the line La representing the inner surface of the directional electromagnetic steel sheet and a point on the line Lb representing the outer surface of the directional electromagnetic steel sheet in a side view of the directional electromagnetic steel sheet. When F and point G are defined as follows, a line delimited by point D and point E on line La representing the inner surface of the grain-oriented electrical steel sheet, a point on line Lb representing the outer surface of the grain-oriented electrical steel sheet An area surrounded by a line divided by F and point G, a straight line connecting point D and point E, and a straight line connecting point F and point G is shown.

Here, the point D, the point E, the point F, and the point G are defined as follows.
In a side view, a straight line adjacent to the center point A of the radius of curvature in the curved portion included in the line La representing the inner surface of the directional electromagnetic steel sheet and the both sides of the curved portion included in the line Lb representing the outer surface of the directional electromagnetic steel sheet The point where the straight line AB connecting the intersection B of the two virtual lines Lb-elongation 1 and Lb-elongation 2 obtained by extending the portion intersects with a line representing the inner surface of the grain-oriented electrical steel sheet is defined as an origin C.
A point separated from the origin C by a distance m represented by the following formula (1) along one line La along the line La representing the inner surface of the grain-oriented electrical steel sheet,
A point separated from the origin C along the line La representing the inner surface of the grain-oriented electrical steel sheet by the distance m in another direction is a point E,
Of the straight line portions included in the line Lb representing the outer surface of the grain-oriented electrical steel sheet, the straight line portion facing the point D and the straight line portion facing the point D are drawn perpendicularly and pass through the point D. Let the point of intersection with the virtual line be point G,
Of the straight line portions included in the line Lb representing the outer surface of the grain-oriented electrical steel sheet, the straight line portion facing the point E and the straight line portion facing the point E are drawn perpendicularly and pass through the point E. Let the intersection with the virtual line be a point F.
Formula (1): m = r × (π / 4)
(In formula (1), m represents the distance from the point C, and r represents the distance (curvature radius) from the center point A to the point C).

  That is, r indicates the radius of curvature when the curve near the point C is regarded as an arc, and in the present disclosure, represents the inner radius of curvature in a side view of the bent portion. The curvature of the curved portion of the bent portion is steeper as the radius of curvature r is smaller, and the curvature of the curved portion of the bent portion is more gradual as the radius of curvature r is larger.

The wound core can be produced by a conventionally known method. Hereinafter, an example of a method for producing a wound core will be described in the case of a wound core having one or more joints and one or more bent portions.
First, the grain-oriented electrical steel sheet sorted in the sorting step is prepared.
Next, after cutting the directional electromagnetic steel sheet to a desired length as necessary, by bending at least one place in each corner portion formation region pre-assigned on the directional electromagnetic steel sheet, A directional electromagnetic steel sheet is formed into a bent body in which flat portions and corner portions are alternately continued, and an angle formed by two flat portions adjacent to each other at each corner portion is 90 °.
A bending method will be described with reference to the drawings. FIG. 11 is a schematic diagram illustrating an example of a bending method in the method of manufacturing a wound core.
Although the configuration of the processing machine is not particularly limited, for example, as shown in FIG. 11, a guide or the like that normally has a die and a punch for pressing, and further fixes a grain-oriented electrical steel sheet. Have. The grain-oriented electrical steel sheet is transported in the transport direction and fixed at a preset position. Next, by adjusting the preset clearance (c) and stroke (s) with a punch, a bent body having a bent portion with a bending angle φ is obtained.
The radius of curvature r of the bent portion can usually be adjusted by changing the distance between the die and the punch and the shape of the die and the punch.

Usually, in the production process of the wound core, the distortion of the bent portion is removed by annealing after the bending process.
Next, the directional electrical steel sheet, which is the bending processed body, is formed by aligning the corners and stacking them in the thickness direction to form a substantially rectangular laminate in a side view. Can be obtained. The obtained wound core body may be used as a wound core as it is, but may be further fixed by using a known fastening tool such as a binding band or the like as necessary.

  The present disclosure is not limited to the above embodiment. The above-described embodiments are exemplifications, and the present disclosure has any configuration that has substantially the same configuration as the technical idea described in the claims of the present disclosure and that exhibits the same operational effects. Are included in the technical scope.

(Reference Experimental Examples 1 to 48)
Same iron loss (W17 / 50 = 0.83W / kg ) group of oriented electrical steel sheet having (Material: 23ZH) was prepared to measure the ₈ values _B by Epstein test for each oriented electrical steel sheet.
The results are shown in Table 1.
Incidentally, the grain-oriented electrical steel sheet was prepared having a glass film containing forsterite (Mg 2 _{SiO 4)} on the base steel sheet. W17 / 50 is an iron loss value at 1.7 T / 50 Hz.
Then (In Table 1, numerals: A, B, C, D) oriented electrical _steel sheet ₈ value B differs from the set of oriented electrical steel sheet were selected, the wound core with the oriented electrical steel sheet Manufactured and installed electrical windings.
A wound iron core has one joint and a wound core (Trancocore) that does not have a bent part, a wound iron core (Unicore) that has one joint and has a bent part, and two joined parts. Three types of wound cores (duo cores) possessed and having bent portions were manufactured.
The tranco core was manufactured by laminating the directional electromagnetic steel sheet after bending the directional electromagnetic steel sheet at 150 ° C. Unicore and Duocore are bent while adjusting the directional electrical steel sheet to 150 ° C. to obtain a directional electrical steel sheet having a bent portion with a bending angle φ of 45 °, and then laminating the directional electrical steel sheets. It was manufactured by doing.
In addition, three types of wound cores were manufactured by changing the gap length of the joint to 0.5, 1, 2, 3 mm, respectively.

[Evaluation]
With respect to the wound cores of Reference Experimental Examples 1 to 48 (average core length: 0.704 m, core mass: about 37 kg, capacity: 25 KVA, dimensions shown in FIG. 12), respectively, using Epstein tester described in JIS C 2550-1 an excitation current method in the measurement method of the magnetic properties of electrical steel strip, frequency 50 Hz, was measured under the conditions of the magnetic flux density 1.7 T, was determined iron loss value W _a of the wound core.
Then, the iron loss value _{W A} of the wound core was determined building factor (BF) divided by the iron loss value of a grain-oriented electrical steel sheet used as material (W17 / 50 = 0.75W / kg ).
In this indication, it can be evaluated that it is a wound iron core by which iron loss was reduced, so that BF was small.
Then, the relationship between the joint gap length and the iron loss deterioration when the gap length of the joint portion of the three types of wound cores was changed to 0.5, 1, 2, 3 mm without inserting the winding was evaluated.
The results are shown in Table 2. In addition, the joint part void length measured all the joint parts of one wound iron core, and described all the averages as a numerical value.

As shown in Table 2, Yunikoa, the Tran cocoa, variation in the iron loss value of the wound core according to the magnitude of the B ₈ value of the material is hardly observed even little variation in iron loss value due to a difference in the joint gap length I can't.
On the other hand, in the Deyuokoa, variation in the iron loss value of the wound iron core due to the difference in the junction gap length is rarely seen, the direction of the wound core of using a ₈ value material B is high, low iron loss I understand that

Tables 3 and 4, as well, as shown in Table 5 and Table 6, in the material to D, using high material C~D relatively B ₈ value shown in Tables 4 and 6 in the material of Deyuokoa , preferable to use a low material A~B relatively B ₈ value on the material of the Yunikoa is, using material A~B shown in tables 3 and 5 the material of Deyuokoa, material C~D the material Yunikoa It turns out that the average value of BF becomes lower than the case of using, and a wound iron core with a lower iron loss can be obtained. It can be seen from Table 2 that this is the same in Tables 3 to 6 even when unicore is changed to trancocore.
Therefore, according to the present disclosure, the same iron loss, and, directional electromagnetic _eight value B obtained by selecting a high-oriented electrical steel sheet relatively B ₈ values from the different family oriented electrical steel sheet It turns out that the said iron core with a low iron loss can be manufactured efficiently by using a steel plate as a material of the iron core which has two or more junction parts.
Further, according to the present disclosure, in addition to the above, the iron loss is the same, and, ₈ value B by selecting a low-oriented electrical steel sheet relatively B ₈ values from the different family oriented electrical steel sheets obtained By using the grain-oriented electrical steel sheet as a material for a wound core with less than two joints, the group of grain-oriented electrical steel sheets can be used for the production of a wound core with a low iron loss without leaving the group efficiently. I understand that I can do it.

DESCRIPTION OF SYMBOLS 1, 1a Directional electrical steel sheet 2 Laminated body 3 Corner part 4, 4a, 4b Plane part 5, 5a, 5b, 5c Bending part 6 Joining part 10 Winding core body (winding core)

Claims (8)

A method for selecting a group of grain-oriented electrical steel sheets used as a material for a wound core,
Identical iron loss and a step of intensity H of the magnetic field to prepare the set of oriented electrical _steel sheet ₈ value magnetic flux density B is different when the 800A / m,
For the set of oriented electrical steel sheet, and measuring the B ₈ value by Epstein test,
Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value greater than a predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by Selecting as a wound core material having at least two joints in one turn;
A method for sorting grain-oriented electrical steel sheets, comprising: Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value less than the predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by The method for sorting grain-oriented electrical steel sheets according to claim 1, wherein the joint portion is sorted as a material of a wound core having less than two locations. The wound core includes a substantially rectangular wound core body in a side view,
The wound core body is composed of the grain-oriented electrical steel sheet, and planar portions and corner portions are alternately continued in the longitudinal direction, and an angle formed between two planar portions adjacent to each corner portion is 90 °. The method for sorting grain-oriented electrical steel sheets according to claim 1 or 2, wherein the grain-oriented electrical steel sheets are stacked in the thickness direction and have a substantially rectangular laminated structure in a side view.   In the wound iron core having two or more joint portions, each corner portion has one or more bent portions having a curved shape in a side view of the grain-oriented electrical steel sheet, and one corner The method for selecting grain-oriented electrical steel sheets according to claim 3, wherein the total bending angle of each bent portion existing in the portion is 90 °. Iron loss identical, and the steps of the strength H of the magnetic field to prepare a group of grain-oriented electrical _steel sheet ₈ value magnetic flux density B is different when the 800A / m,
For the set of oriented electrical steel sheet, and measuring the B ₈ value by Epstein test,
Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value greater than a predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by Selecting as a wound core material having at least two joints in one turn;
Creating the wound iron core using the selected grain-oriented electrical steel sheet;
A method for manufacturing a wound iron core, comprising: Among the group of oriented electrical steel sheet, a grain-oriented electrical steel sheet having a B ₈ value less than the predetermined value set from the range of the B ₈ value of the measured the set of oriented electrical steel sheet obtained by The method for manufacturing a wound core according to claim 5, wherein the joint is selected as a material for a wound core having less than two locations. The wound core includes a substantially rectangular wound core body in a side view,
The wound core body is composed of the grain-oriented electrical steel sheet, and planar portions and corner portions are alternately continued in the longitudinal direction, and an angle formed between two planar portions adjacent to each corner portion is 90 °. The manufacturing method of the wound iron core of Claim 5 or 6 which has a lamination | stacking structure of a substantially rectangular shape in the side view by which the directionality electromagnetic steel plate was piled up in the plate | board thickness direction.   In the wound iron core having two or more joint portions, each corner portion has one or more bent portions having a curved shape in a side view of the grain-oriented electrical steel sheet, and one corner The manufacturing method of the wound iron core of Claim 7 whose sum total of the bending angle of each bending part which exists in a part is 90 degrees.