Specification
Title of invention: Stator core, rotary electric machine, stator core design method
Technical field
[0001]
The present invention relates to a stator core, a rotating electrical machine, and a stator core design method. In particular, it is suitable for use in a stator core having a plurality of laminated electromagnetic steel sheets.
This application claims priority based on Japanese Patent Application No. 2019-206649 filed in Japan on November 15, 2019, the content of which is incorporated herein.
Background technology
[0002]
Magnetic steel sheets are mainly used as the stator core (iron core) of rotating electric machines. Electrical steel sheets are roughly classified into grain-oriented electrical steel sheets and non-oriented electrical steel sheets. The magnetic properties of an electrical steel sheet generally have anisotropy within the plane of the sheet. In particular, the grain-oriented electrical steel sheet has a large anisotropy of magnetic properties, and the magnetic properties in the rolling direction are extremely better than those in other directions. On the other hand, even non-oriented electrical steel sheets have anisotropy in magnetic properties, although the magnetic properties are smaller than those of grain-oriented electrical steel sheets. If a stator core is formed by laminating such magnetic steel sheets having anisotropic magnetic properties, there will be portions with good magnetic properties and portions with poor magnetic properties, resulting in variations in the distribution of the magnetic properties of the stator core. Specifically, the magnetic flux density in the stator core varies, resulting in an increase in iron loss.
[0003]
In Patent Document 1, the passage dimension of the magnetic flux between the groove bottom and the outer periphery of the stator core (that is, the length in the radial direction of the yoke of the stator core) is reduced in the region with good magnetic characteristics, and in the region with poor magnetic characteristics. A technology for a rotating electrical machine that is enlarged by . In the rotating electric machine technology disclosed in Patent Document 1, the cross-sectional area of ​​the yoke of the stator core is varied according to the magnetic properties, so that the magnetic flux density becomes lower for the same magnetic flux in areas with poorer magnetic properties. make it
Patent Document 2 discloses a technique of a three-pole core in which the surface area of ​​the magnetic pole teeth in the rolling direction or the direction perpendicular to the rolling direction is made narrower than the surface areas of the other magnetic pole teeth. In the three-pole core disclosed in Patent Document 2, by making the surface area of ​​the magnetic pole teeth in the rolling direction or in the direction perpendicular to the rolling direction smaller than the surface areas of the other magnetic pole teeth, the magnetic flux imbalance is eliminated at a low cost. be able to.
prior art documents
patent literature
[0004]
Patent Document 1: Japanese Patent Laid-Open No. 59-10142
Patent Document 2: Japanese Patent Laid-Open No. 8-214476
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0005]
However, in the technique disclosed in Patent Document 1, since the magnetic flux flows from the teeth to the yoke while bending, it is difficult to specify which portion of the yoke in the circumferential direction to increase or decrease the passage dimension. It's not easy. That is, with the technique of Patent Document 1, it is difficult to determine the shape of the stator core, and there is a possibility that the variation in the magnetic flux density cannot be reduced.
In addition, in the technique disclosed in Patent Document 2, it is assumed that the magnetic flux in the direction along the rolling direction or the direction perpendicular to the rolling direction is easier to pass than the magnetic flux in the other directions. It may be difficult for the magnetic flux in the parallel direction to pass through. That is, even if the shape of the tripolar core is determined based on the rolling direction as in the technique of Patent Document 2, there is a possibility that the variation in the magnetic flux density cannot be reduced.
[0006]
The present invention has been made in view of the problems described above, and aims to reduce variations in magnetic flux density and suppress iron loss.
Means to solve problems
[0007]
In order to solve the above problems, the present invention adopts the following configuration.
(1) A stator core according to an aspect of the present invention is a stator core having a plurality of laminated electromagnetic steel sheets, wherein, among the plurality of teeth of the stator core, the width of the teeth along the direction in which the magnetic properties are excellent is Narrower than the tooth width along the direction of poor magnetic properties.
(2) In the stator core described in (1) above, in the teeth of the stator core, the product of the width of the teeth of the stator core and the magnetic flux density of the teeth when excited with a predetermined magnetic field strength is approximately may be constant.
(3) The stator core according to (1) or (2) above is configured by laminating rolled electromagnetic steel sheets, and the electromagnetic steel sheets contain, in mass%, C: 0.0100% or less, Si : 1.50% to 4.00%, sol. Al: 0.0001% to 1.0%, S: 0.0100% or less, N: 0.0100% or less, one or more selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au : 2.50% to 5.00% in total, Sn: 0.000% to 0.400%, Sb: 0.000% to 0.400%, P: 0.000% to 0.400%, and One or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total, Mn content (mass %) is [Mn], Ni content (mass%) is [Ni], Co content (mass%) is [Co], Pt content (mass%) is [Pt], Pb content (mass%) [Pb], Cu content (% by mass) [Cu], Au content (% by mass) [Au], Si content (% by mass) [Si], sol. The Al content (% by mass) is measured as [sol. Al], the following formula (1) is satisfied, the balance is Fe and impurities, and the B50 value in the rolling direction is B50L, and the B50 value in the direction tilted 45° from the rolling direction is B50D1, the value of B50 in the direction inclined by 90° from the rolling direction is B50C, and the value of B50 in the direction inclined by 135° from the rolling direction is B50D2, the following expressions (2) and (3) are satisfied. , the {100} <011> X-ray random intensity ratio is 5 or more and less than 30, the plate thickness is 0.50 mm or less, and the direction in which the magnetic properties are excellent is the direction at an angle of 45° from the rolling direction. wherein the directions with inferior magnetic properties are directions with angles of 0° and 90° from the rolling direction, and the tooth width along the direction with an angle of 45° from the rolling direction is may be narrower than either of the width of the teeth along the direction in which the angle is 0° and the width of the teeth along the direction in which the angle is 90° from the rolling direction.
([Mn] + [Ni] + [Co] + [Pt] + [Pb] + [Cu] + [Au]) - ([Si] + [sol. Al]) > 0% (1)
(B50D1+B50D2)/2>1.7T (2)
(B50D1+B50D2)/2>(B50L+B50C)/2 (3)
Here, the magnetic flux density B50 is the magnetic flux density when excited with a magnetic field strength of 5000 A/m.
(4) The stator core described in (3) above may satisfy the following expression (4).
(B50D1+B50D2)/2>1.1×(B50L+B50C)/2 (4)
(5) The stator core described in (3) above may satisfy the following expression (5).
(B50D1+B50D2)/2>1.2×(B50L+B50C)/2 (5)
(6) The stator core described in (3) above may satisfy the following expression (6).
(B50D1+B50D2)/2>1.8T (6)
(7) A rotating electrical machine according to an aspect of the present invention includes the stator core according to any one of (1) to (6) above.
(8) A stator core designing method according to an aspect of the present invention is a designing method for a stator core having laminated electromagnetic steel sheets, and obtains information on the magnetic flux density of teeth when excited with a predetermined magnetic field strength. and the width of the teeth of the stator core so that the product of the width of the teeth of the stator core and the magnetic flux density of the teeth obtained by the step of obtaining the magnetic flux density of the stator core is substantially constant for each tooth. and a determining step of determining
(9) The stator core design method according to (8) above includes an operation data acquisition step of acquiring operation data of the rotating electrical machine when the rotating electrical machine including the stator core is operated, and an operation data acquiring step of acquiring the operation data. Based on the obtained operating data, a specifying step of specifying an operating condition with the highest operating time ratio among a plurality of operating conditions, and an average magnetic flux of the teeth corresponding to the operating condition with the highest ratio specified by the specifying step an average magnetic flux density acquiring step of acquiring density information; and an average magnetic field intensity calculating step of calculating the average magnetic field intensity of the teeth from the information of the average magnetic flux density of the teeth acquired by the average magnetic flux density acquiring step. , wherein the tooth magnetic flux density acquisition step may acquire information on the magnetic flux density of the teeth when excited with the average magnetic field strength calculated in the average magnetic field strength calculation step.
(10) The stator core design method according to (8) above includes an operation data acquisition step of acquiring operation data of the rotating electric machine when the rotating electric machine including the stator core is operated, and an operation data acquiring step of acquiring the operation data. an identifying step of identifying the operating time ratio for each of a plurality of operating conditions based on the obtained operating data; and an average magnetic flux density obtaining step of obtaining information on the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions. and calculating the average magnetic field strength of the teeth for each of the plurality of operating conditions from the information of the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions acquired by the average magnetic flux density acquiring step. and a strength calculation step, wherein the tooth magnetic flux density obtaining step is performed when the teeth are excited with the average magnetic field strength for each of the plurality of operating conditions calculated by the average magnetic field strength calculation step, Information on the magnetic flux density of the teeth for each of the plurality of operating conditions is acquired, and in the determination step, the product of the width of the teeth of the stator core and the magnetic flux density of the teeth acquired in the tooth magnetic flux density acquisition step is calculated for each tooth. Calculate the width of the teeth for each of the plurality of operating conditions so that it is substantially constant at , and calculate the width of the teeth for each of the plurality of operating conditions, based on the ratio of the operating time specified by the specifying step Weighting may be applied to determine the width of the tooth after weighting.
(11) The stator core design method described in (8) above includes an operation data obtaining step of obtaining operation data of the rotating electric machine when the rotating electric machine including the stator core is operated, and an operation data obtaining step of obtaining the operation data. an identifying step of identifying the operating time ratio for each of a plurality of operating conditions based on the obtained operating data; and an average magnetic flux density obtaining step of obtaining information on the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions. , from the information of the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions acquired by the average magnetic flux density acquiring step, the evaluated magnetic flux of the teeth weighted based on the ratio of the operating time specified by the specifying step and an average magnetic field strength calculation step of calculating the average magnetic field strength of the teeth from the evaluated magnetic flux density of the teeth calculated by the evaluation magnetic flux density calculation step. In the tooth magnetic flux density acquisition step, information on the magnetic flux density of the teeth when excited with the average magnetic field intensity of the teeth calculated in the average magnetic field intensity calculation step may be acquired.
(12) In the stator core design method according to any one of (9) to (11) above, in the operation data acquisition step, at least one of planned data and actual data of a rotating electric machine including the stator core is acquired. Driving data may be obtained.
Effect of the invention
[0008]
According to the above aspect of the present invention, it is possible to reduce variations in magnetic flux density and suppress iron loss.
Brief description of the drawing
[0009]
1 is a diagram showing an example of the configuration of a rotating electrical machine; [0012]FIG.
2] A graph showing the relationship between the angle from the rolling direction and the magnetic properties. [FIG.
3 is a diagram for explaining the width of teeth; FIG.
4 is a diagram showing an example of the configuration of a motor; FIG.
5 is a diagram showing angles of 0° to 90° from the rolling direction of the stator core. FIG.
6 is a table showing the relationship between the torque ratio and the average magnetic flux density of teeth; FIG.
7 is a table showing the relationship between the torque ratio and the magnetic flux density of teeth for each angle from the rolling direction (Material A). FIG.
[Fig. 8] Torque ratio and optimal tooth width for each angle from the rolling directionIt is a table showing the relationship (Material A).
9 is a table showing iron loss ratios of comparative examples and invention examples (material A). FIG.
10 is a table showing an example of operating data; FIG.
11 is a table showing tooth width weighted based on the ratio of operating time for each angle from the rolling direction (Material A). FIG.
12 is a table showing the relationship between the torque ratio and the magnetic flux density of teeth for each angle from the rolling direction (Material B). FIG.
13 is a table showing the relationship between the torque ratio and the optimum tooth width for each angle from the rolling direction (Material B). FIG.
14 is a table showing iron loss ratios of comparative examples and invention examples (material B). FIG.
15 is a table showing tooth width weighted based on the ratio of operating time for each angle from the rolling direction (Material B). FIG.
16 is a diagram showing an example of the configuration of a motor; FIG.
17 is a view showing angles of 0° to 90° from the rolling direction in the stator core. FIG.
18 is a table showing the relationship between the torque ratio and the average magnetic flux density of teeth; FIG.
19 is a table showing the relationship between the torque ratio and the magnetic flux density of teeth for each angle from the rolling direction (Material A). FIG.
20 is a table showing the relationship between the torque ratio and the optimum tooth width for each angle from the rolling direction (Material A). FIG.
21 is a table showing iron loss ratios of comparative examples and invention examples (material A). FIG.
22 is a table showing tooth width weighted based on the ratio of operating time for each angle from the rolling direction (Material A). FIG.
23 is a table showing the relationship between the torque ratio and the magnetic flux density of teeth for each angle from the rolling direction (Material B). FIG.
24 is a table showing the relationship between the torque ratio and the optimum tooth width for each angle from the rolling direction (Material B). FIG.
25 is a table showing iron loss ratios of comparative examples and invention examples (material B). FIG.
26 is a table showing tooth width weighted based on the ratio of operating time for each angle from the rolling direction (Material B). FIG.
27 is a diagram showing an example of a functional configuration of a stator core design device; FIG.
28 is a flow chart showing an example of processing of a stator core design device; FIG.
29 is a flowchart showing an example of processing of a stator core design device; FIG.
30 is a flowchart showing an example of processing of a stator core design device; FIG.
MODE FOR CARRYING OUT THE INVENTION
[0010]
An embodiment of the present invention will be described below with reference to the drawings. The XYZ coordinates shown in each figure indicate the orientation relationship in each figure, and the origin of the XYZ coordinates is not limited to the position shown in each figure. Also, in the following description, the same length, shape, direction, size, interval, and other physical quantities are not limited to being exactly the same, and the functions of the target portion are not impaired. Including when the range is different.
[0011]

FIG. 1 is a diagram showing an example of the configuration of a rotating electric machine 100. As shown in FIG. Specifically, FIG. 1 is a diagram showing a cross section of the rotary electric machine 100 taken perpendicularly to its axis O. As shown in FIG. In the following description, the circumferential direction of the rotating electrical machine 100 (the direction around the axis O of the rotating electrical machine 100), the radial direction (the direction radially extending from the axis O of the rotating electrical machine 100), the height direction (the direction parallel to the axis O ( The Z-axis direction)) is abbreviated as the circumferential direction, the radial direction, and the height direction, respectively, as necessary. Further, the axis O of the rotary electric machine 100 is abbreviated as the axis O as necessary.
[0012]
In FIG. 1, a rotating electric machine 100 has a rotor 110 and a stator 120 .
The rotor 110 is attached to the rotating shaft 130 directly or via a member so as to be coaxial with the rotating shaft 130 (axis O). The rotor 110 has, for example, a rotor core (iron core), permanent magnets, and a rotating shaft (shaft). Since the rotor 110 can be realized by a known technology, its detailed description is omitted here.
[0013]
The stator 120 is arranged outside the rotor 110 so as to be coaxial with the rotating shaft 130 (axis O). Stator 120 has a stator core and a coil. For convenience of notation, illustration of the coil is omitted in FIG. The stator core has a plurality of teeth 121 a - 121 p and a yoke 122 . Yoke 122 has a generally hollow cylindrical shape. Teeth 121 a - 121 p radially extend from the inner peripheral surface of yoke 122 toward axis O. As shown in FIG. The teeth 121a-121p are arranged at regular intervals in the circumferential direction. The teeth 121a-121p and the yoke 122 are integrated. That is, the teeth and yokes have no boundaries. Also, there are no border lines that exist within the yoke in the case of so-called split cores.
[0014]
The positions of the rotor 110 and the stator 120 are determined so that the tip surfaces of the plurality of teeth 121a to 121p face the outer peripheral surface of the rotor core of the rotor 110 with an interval (air gap) therebetween. Coils (windings) are arranged for each of the plurality of teeth 121a to 121p while being electrically insulated from the teeth 121a to 121p. The winding method of the coil may be distributed winding or concentrated winding. A rotating magnetic field is generated by applying an exciting current to the coils of the stator 120, and the rotor 110 rotates due to the rotating magnetic field.
[0015]
Here, a case where the rotary electric machine 100 is an inner rotor type motor (electric motor) will be described as an example. Applications of the motor include, for example, electric vehicles, hybrid electric vehicles, and compressors, but the application of the motor is not particularly limited.
[0016]
In this embodiment, the stator core is configured using a non-oriented electromagnetic steel sheet as an example of an electromagnetic steel sheet. As the non-oriented electrical steel sheet, for example, one conforming to the "non-oriented electrical steel strip" defined in JIS C 2552 (2014) is used.
The stator core is formed by laminating and fixing a plurality of non-oriented electrical steel sheets having the same shape and size as non-oriented electrical steel sheets cut to match the overall planar shape of the stator core (the shape shown in FIG. 1). Configured. Fixing of the stator core is achieved by using, for example, crimping. A method for cutting out the non-oriented electrical steel sheet is not particularly limited. For example, the non-oriented electrical steel sheet can be cut out using die punching, wire electric discharge machining, or the like.
[0017]
In FIG. 1, two types of angles are shown for the convenience of the explanation that will be described later. The angles (0°, 22.5°, 45°, 67.5°, 90°) shown without parentheses in FIG. 90° or less out of the angles formed by the rolling direction of the magnetic steel sheet and the radial direction of the teeth 121a to 121p. Angles shown in parentheses in FIG. , 225°, 247.5°, 270°, 292.5°, 315°, 337.5°, 360°) is the rolling direction of the non-oriented electrical steel sheet that faces the positive direction of the X axis. The angle is shown when the reference (0 [°]) is used and the counterclockwise direction toward the paper surface of FIG. 1 is expressed as the positive direction. Thus, in FIG. 1, angles shown without parentheses and angles shown with parentheses after them are notated differently, but have the same meaning.
[0018]
Here, the radial direction of the teeth 121a to 121p is a plane (X-Y 1) extends parallel to the plane). FIG. 1 shows an example in which the rolling direction of the non-oriented electrical steel sheet is the X-axis direction.
In the following description, when the rolling direction of the non-oriented electrical steel sheet is used as a reference, the angle formed by the rolling direction of the non-oriented electrical steel sheet and the radial direction of the teeth 121a to 121p is is called the angle from In the following description, for convenience of explanation, the angle from the rolling direction will be described as an angle defined as the angle shown without parentheses in FIG. There are cases where it is described as an angle defined like the angle shown, but as described above, the angle shown without parentheses and the angle shown with parentheses after that are different in notation. and have the same meaning.
[0019]
In the present embodiment, the plurality of non-oriented electrical steel sheets cut out as described above are laminated with the angles from the rolling direction aligned. That is, among the plurality of regions of the non-oriented electrical steel sheet cut out as described above, the region belonging to the same tooth (angle defined as the angle shown without parentheses in FIG. 1) The angle from the rolling direction will be the same.
[0020]
In this embodiment, a first non-oriented electrical steel sheet (referred to as material A) and a second non-oriented electrical steel sheet (referred to as material B) having different magnetic properties with respect to the angle from the rolling direction A case will be described in which two types of non-oriented electrical steel sheets are used to form the respective stator cores.
　Material A is a steel sheet with relatively small anisotropy, with the angle of 0° from the rolling direction being the direction with the best magnetic properties. Material B is a steel sheet having a relatively large anisotropy in which the angle of 45° from the rolling direction is the direction in which the magnetic properties are most excellent.
[0021]
FIG. 2 is a graph showing the relationship between the angle from the rolling direction and the magnetic properties of each of material A and material B. The magnetic property is, for example, the magnitude of the magnetic flux density, here the magnitude of the magnetic flux density (B50) when excited with a magnetic field strength of 5000 [A/m].
Graph 201 shows the normalized magnetic flux density B50 of material A, and graph 502 shows the normalized magnetic flux density B50 of material B. The normalized magnetic flux densities B50 in the graphs 201 and 202 are indicated by the ratio when the average of B50 for each angle from the rolling direction in the material A is normalized to 1.000. Also, in FIG. 2, for convenience of notation, the notation of the angle from the rolling direction is the same notation as the angle shown in parentheses in FIG.
[0022]
Material A has the highest magnetic flux density at an angle of 0° from the rolling direction, and the magnetic flux density increases at intervals of 90° from 0°. Further, the magnetic flux density is small near the angle of 45° from the rolling direction, and the magnetic flux density is small at intervals of 90° from the angle of 45°. That is, in material A, the directions with excellent magnetic properties are at angles of 0°, 90°, 180°, and 270° from the rolling direction, and the directions with poor magnetic properties are at angles of 45°, 135°, It is near 225° and 315°. Below, as representative values ​​of the direction in which the magnetic properties of material A are inferior, angles of 45°, 135°, 225°, and 315° from the rolling direction are described. Further, in the material A, the magnetic flux density in the angle range of 0° to 90° and the magnetic flux density in the angle range of 90° to 180° are substantially symmetric with respect to the angle of 90°. Further, in material A, the magnetic flux density in the range of angles 0° to 180° and the magnetic flux density in the range of angles 180° to 360° are substantially symmetrical with the angle of 180° as a boundary.
On the other hand, material B has the highest magnetic flux density at an angle of 45° from the rolling direction, and the magnetic flux density increases at intervals of 90° from 45°. In addition, the magnetic flux density is small near the angle of 0° from the rolling direction, and the magnetic flux density is small at intervals of 90° from 0°. That is, in material B, the directions with excellent magnetic properties are at angles of 45°, 135°, 225°, and 315° from the rolling direction, and the directions with poor magnetic properties are at angles of 0°, 90°, and 90° from the rolling direction. It is near 180° and 270°. Below, as representative values ​​of the direction in which the magnetic properties of material B are inferior, angles of 0°, 90°, 180°, and 270° from the rolling direction are described. Further, in material B, the magnetic flux density in the angle range of 0° to 90° and the magnetic flux density in the angle range of 90° to 180° are substantially symmetric with respect to the angle of 90°. Furthermore, in the material B, the magnetic flux density in the angle range of 0° to 180° and the magnetic flux density in the angle range of 180° to 360°It is substantially symmetrical with respect to 180°.
[0023]
As shown in FIG. 2, when the stator core is made of a material A or a material B having different magnetic flux densities depending on the angle from the rolling direction, the radial direction of each tooth of the stator core has a different angle from the rolling direction. The magnetic flux density of each tooth will be different when excited with a predetermined magnetic field strength. Therefore, the magnetic flux density in the stator core varies, resulting in increased iron loss. When a rotating electrical machine is configured using such a stator core, the efficiency of the rotating electrical machine is reduced.
[0024]
The inventors came up with the idea that the width of each tooth should be adjusted to reduce variations in the magnetic flux density in the stator core. Specifically, the inventors found that the width of the teeth along the direction with excellent magnetic properties should be narrower than the width of the teeth along the directions with poor magnetic properties, or the width along the directions with poor magnetic properties. The inventors have arrived at the idea that the width of the teeth should be wider than the width of the teeth along the direction in which the magnetic properties are excellent. Furthermore, the inventors believe that in order to further reduce variations in magnetic flux density, the width of the teeth should be determined so that "the width of the teeth" x "the magnetic flux density of the teeth" is substantially constant for each tooth. reached.
[0025]
If the stator core is configured based on the idea as described above, among the teeth 121a to 121p shown in FIG. The stator core is configured to be narrower than
Specifically, first, when the stator core shown in FIG. 1 is constructed using material A, the direction in which magnetic properties are excellent in material A is the direction at an angle of 0° from the rolling direction. Here, in material A, the direction in which the magnetic properties are excellent is the direction at an angle of 0° from the rolling direction, in addition to the angle of 0°, the directions at angles of 90°, 180°, and 270° from the rolling direction. Say. Further, in material A, the direction in which the magnetic properties were inferior was the direction at an angle of 45° from the rolling direction. Here, in material A, the direction in which the magnetic properties are inferior is the direction at an angle of 45° from the rolling direction, in addition to the angle of 45°, the directions at angles of 135°, 225°, and 315° from the rolling direction. Say. That is, in material A, the magnetic properties are excellent at angles of 0°, 90°, 180°, and 270° from the rolling direction, and the magnetic properties are poor at angles of 45°, 135°, 225°, and 315° from the rolling direction. is the direction. Therefore, by making the width of each of the teeth 121a, 121e, 121i, and 121m narrower than the width of each of the teeth 121c, 121g, 121k, and 121o, it is possible to reduce variations in magnetic flux density within the stator core.
On the other hand, when the stator core shown in FIG. 1 is constructed using material B, the direction in which magnetic properties are excellent in material B is the direction at an angle of 45° from the rolling direction. Here, in material B, the direction in which the magnetic properties are excellent is the direction at an angle of 45° from the rolling direction, in addition to the angle of 45°, the directions at angles of 135°, 225°, and 315° from the rolling direction. Say. In material B, the directions with inferior magnetic properties are the directions at angles of 0° and 90° from the rolling direction. Here, in material B, the directions in which the magnetic properties are inferior are the directions at angles of 0° and 90° from the rolling direction, in addition to angles of 0° and 90°, angles of 180° and 270° from the rolling direction. refers to the direction of That is, in material B, the magnetic properties are excellent at angles of 45°, 135°, 225°, and 315° from the rolling direction, and the magnetic properties are poor at angles of 0°, 90°, 180°, and 270°. is the direction. Therefore, by making the width of each of the teeth 121c, 121g, 121k, and 121o narrower than the width of each of the teeth 121a, 121e, 121i, and 121m, variations in magnetic flux density within the stator core can be reduced.
[0026]
Here, the width of the teeth will be explained with reference to FIG. FIG. 3 is a diagram for explaining the width of teeth. (a) of FIG. 3 is an example of teeth parallel to each other along the radial direction. In this example, the teeth themselves are parallel along the radial direction. (b) of FIG. 3 is an example of teeth having parallel slots along the radial direction. In this example, slots located between circumferentially adjacent teeth are parallel in the radial direction.
The width of the teeth in this embodiment is the length in the circumferential direction of the stator core at the center position of the tooth linear region. The tooth linear region is defined as the region of the longest straight line among the straight lines that constitute the ends of the teeth in the circumferential direction of the stator core in the cross section of the stator core when cut in the direction perpendicular to the axis of the stator core. It is obtained for each of the two ends of the tooth.
In the example shown in FIG. 3(a), the straight line connecting the positions 311 and 312 and the straight line connecting the positions 313 and 314 are the tooth straight line regions. In addition, in the example shown in FIG. 3A, the central positions of the teeth linear regions are positions 321 and 322 . Therefore, the width of the teeth shown in FIG. 3(a) is the distance TW between the positions 321 and 322. As shown in FIG.
In the example shown in (b) of FIG. 3, the straight line connecting the positions 315 and 316 and the straight line connecting the positions 317 and 318 are tooth straight line regions. Also, in the example shown in FIG. 3B, the central positions of the tooth linear regions are positions 323 and 324 . Therefore, the width of the teeth shown in FIG. 3(b) is the distance TW between the positions 323 and 324. FIG.
[0027]
In FIG. 3(a), since it is an example of teeth that are parallel along the radial direction, the width of the teeth is constant regardless of where in the radial direction in the tooth linear region.
On the other hand, in FIG. 3(b), since the slot is an example of teeth parallel to each other along the radial direction, the actual width of the teeth differs depending on where in the tooth linear region in the radial direction, The width of the teeth is the distance TW between the positions 323 and 324 described above as a representative value.
[0028]

Next, when the magnetic steel sheet is the material A and the stator core of the embedded permanent magnet type synchronous motor is designed, the above-mentioned "tooth width" x "teeth magnetic flux density" is substantially constant for each tooth. An example of determining the width of teeth will be described. In the example of the embedded permanent magnet type synchronous motor shown here, the teeth of the stator core have parallel slots along the radial direction as shown in FIG. 3(b).
FIG. 4 is a diagram showing an example of the configuration of the motor 400 before determining the width of the teeth, ie, the width of each tooth is constant over the entire circumference. FIG. 4 shows a cross section of the motor 400 taken perpendicular to its axis O. FIG.
In FIG. 4, the motor 400 is an interior permanent magnet synchronous motor (IPMSM) and has a rotor 410 and a stator 420 .
The rotor 410 is attached to the rotating shaft 430 so as to be coaxial with the rotating shaft 430 (axis O). Rotor 410 has a plurality of permanent magnets 411 . Permanent magnets 411 are embedded in rotor core 415 . As shown in FIG. 4, the motor 400 has eight poles. The outer diameter of rotor 410 is 133 [mm].
The stator 420 has a stator core 421 and coils 422 . The outer diameter of stator 420 is 207 [mm], and the inner diameter of stator 420 is 135 [mm]. Moreover, the number of slots of the stator core 421 is 48. Also, the coil 422 is a distributed winding.
[0029]
FIG. 5 is an enlarged view of a portion of the stator core 421 shown in FIG. 4 at an angle of 0° to 90° from the rolling direction. Here, among the teeth 501a to 501m of the stator core 421, the tooth 501a is positioned at an angle of 0° from the rolling direction, and the 1/2 width of the tooth is omitted in the drawing. Further, the tooth 501m among the teeth 501a to 501m is positioned at an angle of 90° from the rolling direction, and the 1/2 width of the tooth is omitted in the drawing.
Also, each tooth has a shape in which the slots are parallel along the radial direction, as shown in FIG. 3(b). As shown in FIG. 5, the teeth have a root width TW1 of 6.56 mm and a tip width TW2 of 5.16 mm. Therefore, the tooth width (TW shown in FIG. 3B) is 5.86 mm by calculating (6.56 mm+5.16 mm)/2.
[0030]
Here, the result of analyzing the relationship between the operating conditions (torque ratio) and the average magnetic flux density of the teeth when the rotation speed of the motor 400 is 3,000 [rpm] and the width of the teeth is constant over the entire circumference of the stator core 421. is shown in FIG.
FIG. 6 is a table showing the relationship between the torque ratio [%], which is the operating condition of the motor 400, and the average magnetic flux density B [T peak] of the teeth. Here, the torque ratio represents the torque ratio under each operating condition, with the maximum torque being 100[%]. For example, a torque ratio of 20 [%] means operating with a torque value [Nm] of maximum torque [Nm]×0.2. Further, the average magnetic flux density of the teeth is a value obtained by averaging the maximum values ​​of the magnetic flux densities at each location in the 48 teeth. In other words, the peak in [Tpeak] indicates the peak magnetic flux density when the magnetic flux density changes with the passage of time. In FIG. 6, the average magnetic flux density of the teeth increases as the torque ratio increases. The relationship between the torque ratio and the average magnetic flux density of the teeth shown in FIG. can be derived by integrating When obtaining from electromagnetic field analysis (numerical analysis), the maximum magnetic flux density is calculated for each element (all meshes) included in the tooth part (all 48 teeth in this example) in the finite element method, and the area of ​​each element The average magnetic flux density can be obtained by averaging in consideration of In the case of actual measurement using search coils, the time waveform of the magnetic flux density is obtained by integrating the induced voltage measured for each search coil, and then the maximum magnetic flux density is calculated. By averaging considering the area, the average magnetic flux density is obtained.
[0031]
From the average magnetic flux density of the teeth shown in FIG. 6, the average magnetic field intensity H [A/m] of the teeth is calculated. The average magnetic field strength of the teeth can be calculated based on the relative magnetic permeability of the material A. Here, the strength of the average magnetic field of the teeth is calculated for each torque ratio (that is, for each average magnetic flux density of the teeth shown in FIG. 6). Next, based on the material properties of the material A, the magnetic flux density B[T] of the teeth for each angle from the rolling direction when the teeth are excited with the average magnetic field strength is calculated. Therefore, the magnetic flux density of the teeth is calculated for each angle from the rolling direction for each torque ratio (that is, for each average magnetic flux density of the teeth shown in FIG. 6).
[0032]
FIG. 7 is a table showing the relationship between the torque ratio [%] and the magnetic flux density B [T] of the teeth for each angle from the rolling direction. Here, angles of 0°, 22.5°, 45°, 67.5°, and 90° from the rolling direction are taken as representative values, and three teeth around the angles of the representative values ​​have the same magnetic flux density.
Teeth with an angle of 0° from the rolling direction are teeth 501a and 501b included in the 0° range (A1) shown in FIG. Teeth having an angle of 22.5° from the rolling direction are teeth 501c to 501e included in the range of 22.5° shown in FIG. Further, the teeth having an angle of 45° from the rolling direction are teeth 501f to 501h included in the 45° range (A3) shown in FIG. Teeth with an angle of 67.5° from the rolling direction are teeth 501i to 501k included in the 67.5° range (A4) shown in FIG. Moreover, the teeth with an angle of 90° from the rolling direction are included in the 90° range (A5) shown in FIG.501 l and 501 m.
[0033]
As shown in FIG. 7, at torque ratios of 20[%], 40[%], 60[%], and 80[%], variations occur in the magnetic flux density of the teeth for each angle from the rolling direction. Further, when the torque ratio is 40 [%], 60 [%], and 80 [%], the magnetic flux density of the teeth at angles of 0° and 90° from the rolling direction is large, and the magnetic flux of the teeth at an angle of 45° from the rolling direction is large. low density; Such a tendency is consistent with the tendency that the B50 ratio is large at an angle of 0° and 90° from the rolling direction, and the B50 ratio is small at an angle of 45° from the rolling direction, as shown in the graph 201 for material A shown in FIG. I am doing it. On the other hand, as shown in FIG. 7, when the torque ratio is 100[%], the magnetic flux density of the teeth is constant regardless of the angle from the rolling direction due to magnetic saturation.
The relationship between the torque ratio shown in FIG. 7 and the magnetic flux density of the tooth at each angle from the rolling direction can be derived from the BH characteristics of material A at the angle from the rolling direction.
[0034]
Next, in order to reduce the variation occurring in the magnetic flux density of the teeth, the optimum width of the teeth is determined for each angle from the rolling direction. Specifically, based on the magnetic flux density of the teeth for each angle from the rolling direction shown in FIG. to decide. Here, the tooth width is determined for each torque ratio.
For example, in FIG. 7, taking the torque ratio of 60% as an example, the magnetic flux density of the teeth is 1.65 [T] at an angle of 0° from the rolling direction, and the magnetic flux density of the teeth is 1.65 [T] at an angle of 22.5° from the rolling direction. 61 [T], tooth magnetic flux density 1.55 [T] at angle 45°, tooth magnetic flux density 1.56 [T] at angle 67.5°, tooth magnetic flux density 1.59 [T] at angle 90° ]. Therefore, even if the angle is 0°, 22.5°, 45°, 67.5°, or 90°, the tooth width to decide. The tooth width determined in this way is called an optimum width.
[0035]
FIG. 8 is a table showing the relationship between the torque ratio [%] and the optimum tooth width [mm] determined for each angle from the rolling direction.
For example, in FIG. 8, taking the case of a torque ratio of 60 [%] as an example, the optimum width of the teeth is 5.64 [mm] at an angle of 0° from the rolling direction, and the optimum width of the teeth is 5.64 [mm] at an angle of 22.5° from the rolling direction. 76 [mm], optimum tooth width 5.99 [mm] at angle 45°, optimum tooth width 5.96 [mm] at angle 67.5°, optimum tooth width 5.85 [mm] at angle 90° ]. Here, the "magnetic flux density of the teeth" in the case of the torque ratio of 60 [%] in FIG. 7 and the "optimum width of the teeth" in the case of the torque ratio of 60 [%] in FIG. 8 are calculated for each angle from the rolling direction. The multiplied products are all 9.3, which is substantially constant.
[0036]
The stator core is designed by applying the optimal tooth width determined in this way to the tooth width corresponding to the angle from the rolling direction.
For example, in FIG. 8, taking the torque ratio of 60 [%] as an example, the widths of the teeth 501a and 501b included in the 0° range (A1) shown in FIG. The width of the teeth 501c to 501e included in the range (A2) is 5.76 [mm], the width of the teeth 501f to 501h included in the 45° range (A3) is 5.99 [mm], and the 67.5° range ( The width of the teeth 501i to 501k included in A4) is set to 5.96 [mm], and the width of the teeth 501l and 501m included in the 90° range (A5) is designed to be 5.85 [mm].
[0037]
In addition, in FIG. 2 described above, as described with the graph 201 showing the relationship between the angle from the rolling direction and the magnetic properties of the material A, the material A has a magnetic flux density and a , and the magnetic flux density in the angle range of 90° to 180° are substantially symmetrical with the angle of 90° as the boundary. Further, in material A, the magnetic flux density in the range of angles 0° to 180° and the magnetic flux density in the range of angles 180° to 360° are substantially symmetrical with the angle of 180° as a boundary.
Therefore, the magnetic flux density B [T] of the tooth for each angle from the rolling direction shown in FIG. Since the angles 168.75° to 191.25° shown in FIG. Designed to have approximately the same width.
Similarly, the teeth included in the angles 146.25° to 168.75°, 191.25° to 213.75°, and 326.25° to 348.75° shown in FIG. 25° to 33.75°: The width is designed to be substantially the same as the width of the teeth included in A2).
Similarly, the teeth included in the angles 123.75° to 146.25°, 213.75° to 236.25°, and 303.75° to 326.25° shown in FIG. ° to 56.25°: The width is designed to be substantially the same as the width of the teeth included in A3).
Similarly, the teeth included in the angles 101.25° to 123.75°, 236.25° to 258.75°, and 281.25° to 303.75° shown in FIG. .25° to 78.75°: Designed to have approximately the same width as the width of the teeth included in A4).
Similarly, the teeth included in the angles 258.75° to 281.25° shown in FIG. design.
[0038]
In this way, in the stator core designed, the width of the teeth along the direction with excellent magnetic properties is narrower than the width of the teeth along the directions with poor magnetic properties. In the material A, the teeth along the direction with excellent magnetic properties are not limited to the teeth along the angle of 0 ° from the rolling direction and the teeth along the angle of 90 ° from the rolling direction, but these teeth Teeth located in the vicinity of are also included. Specifically, in the material A, the teeth along the direction with excellent magnetic properties are included in the angle 348.75 ° to 11.25 °, the teeth included in the angle 168.75 ° to 191.25 °, the angle The teeth included in the angles of 78.75° to 101.25° and the teeth included in the angles of 258.75° to 281.25°.
Further, in the material A, the teeth along the direction of inferior magnetic properties are the teeth along the angle of 45° from the rolling direction, and the teeth along the angles of 135°, 225°, and 315° from the rolling direction. It is not limited to teeth, and includes teeth located in the vicinity of these teeth. Specifically, in material A, the teeth along the direction in which the magnetic properties are inferior are the teeth included in the angles 33.75° to 56.25°, the teeth included in the angles 123.75° to 146.25°, and the teeth included in the angles The teeth included in the angles 213.75° to 236.25° and the teeth included in the angles 303.75° to 326.25°.
[0039]
FIG. 9 is a table showing the relationship between the iron loss ratio [-] between a stator core designed with an optimum tooth width and a stator core with a constant tooth width over the entire circumference for each torque ratio [%]. be. As for the iron loss ratio, a motor with a stator core designed with an optimum tooth width is taken as an example of the invention, and a motor with a stator core with a constant tooth width over the entire circumference is taken as a comparative example. It is a value obtained by dividing the iron loss by the iron loss of the motor of the comparative example. Here, the iron loss ratio is calculated for each torque ratio. The iron loss was measured by electromagnetic field analysis (numerical analysis) under the condition that the motor of the invention example and the motor of the comparative example were each operated at a rotation speed of 3,000 [rpm] so that each torque ratio "%" described above was obtained. can be derived by doing Moreover, it is also possible to derive by actually measuring the manufactured motor.
[0040]
From the results of the iron loss ratio shown in FIG. 9, the iron loss of 0.1 [%] to 1.3 [%] is suppressed at torque ratios of 20 [%], 40 [%], 60 [%], and 80 [%]. I was able to confirm that it is possible. On the other hand, at a torque ratio of 100 [%], as described above, the teeth are magnetically saturated and the magnetic flux density of the teeth is constant regardless of the angle from the rolling direction, so the effect of suppressing iron loss could not be confirmed.
In this way, depending on operating conditions such as the torque ratio, it is possible to reduce variations in the magnetic flux density by determining the tooth width so that the "tooth width" x "magnetic flux density of the teeth" is approximately constant for each tooth. , it was confirmed that iron loss can be suppressed in the region where magnetic saturation does not occur.
[0041]
It should be noted that it is impossible to change the tooth width of a stator core that is actually manufactured after the tooth width has been determined once, every time the operating conditions such as the torque ratio change. Therefore, to design a stator core, for example, a stator core design device selects one operating condition (torque ratio) from among a plurality of operating conditions (a plurality of torque ratios). The stator core is designed by determining the width of the teeth so that the "tooth width"×"the magnetic flux density of the teeth" is constant for each tooth under the selected operating conditions. As a result, variations in the magnetic flux density of the stator core can be reduced under the selected operating conditions.
On the other hand, when operating a motor equipped with a designed stator core, if there is little or no time to operate under the selected operating conditions, the variation in magnetic flux density is actually reduced to suppress iron loss. I can't let you. Therefore, in designing the stator core, it is necessary to determine the width of the teeth in advance so that the iron loss can be minimized in consideration of the operation of the rotary electric machine.
Two design methods for the stator core are described below. Note that the two design methods may be performed by a stator core design device, which will be described later, or by a stator core designer.
[0042]
[First Design Method of Stator Core]
A first design method is to identify an operating condition with the highest ratio of operating time to the total operating time among a plurality of operating conditions, assuming that a rotating electric machine having a stator core to be designed operates, and It is a method of determining the optimum tooth width under specified operating conditions.
FIG. 10 shows an example of operating data assuming that a rotating electric machine equipped with a stator core to be designed operates. Specifically, FIG. 10 shows an example of the operating time ratio according to the torque ratio in the motor 600 having the designed stator core. Here, the running time means the time during which the motor 600 is rotating. The operating data shown in FIG. 10 are obtained in advance before designing the stator core.
[0043]
In FIG. 10, among the plurality of operating conditions, the torque ratio of 30[%] to 50[%] corresponds to the operating condition with the highest operating time ratio because the operating time ratio is 45[%]. Therefore, in this case, from the average magnetic flux density 1.44 [T peak] of the teeth corresponding to the torque ratio of 40 [%] among the torque ratios shown in FIG. Calculate In the above description of , the tooth width for each angle from the rolling direction as shown in FIG. 7 for each torque ratio The magnetic flux density B[T] was calculated, and the optimum tooth width was determined for each angle from the rolling direction as shown in FIG. On the other hand, here, the magnetic flux density B[T] of the teeth for each angle from the rolling direction shown in FIG. 7 is calculated only at the torque ratio of 40[%], which is the highest ratio of the operation time. The optimum tooth width is determined for each angle from the rolling direction shown in FIG.
Therefore, one optimum width for each tooth is determined. By designing the stator core by applying the optimum width determined in this way to the width of the teeth, it is possible to reduce variations in magnetic flux density and suppress iron loss under operating conditions with the highest operating time ratio. .
[0044]
[Second Design Method of Stator Core]
The second design method is to designAssuming that a rotating electric machine having a stator core that is capable of operating is operated, the operating time ratio for each of the plurality of operating conditions is specified, and the tooth width is determined based on the specified operating time ratio for each of the plurality of operating conditions. is a method of weighting
The second design method will also be described with reference to an example of the operating data shown in FIG. Also in the second design method, the operating data shown in FIG. 10 are obtained in advance before designing the stator core.
[0045]
In the second design method, similar to the , the torque ratio shown in FIG. 6 and the average magnetic flux density of the tooth and the relationship between the torque ratio shown in FIG. 7 and the magnetic flux density of the tooth for each angle from the rolling direction. Thereby, the optimum tooth width for each angle from the rolling direction shown in FIG. 8 is calculated for each torque ratio.
Next, the optimum tooth width for each angle from the rolling direction is weighted based on the operating time ratio corresponding to the torque ratio shown in FIG. Specifically, for each angle from the rolling direction shown in FIG. 8, the optimum tooth width for each torque ratio is multiplied by the operating time ratio corresponding to the torque ratio shown in FIG. Here, since there are five types of torque ratios, five values ​​are calculated by multiplying the optimum tooth width for each torque ratio by the operating time ratio corresponding to the torque ratio. Next, by adding the calculated five values ​​and dividing by 100, it is possible to calculate the tooth width weighted based on the ratio of the operating time at an angle from the predetermined rolling direction. Similarly, at angles from other rolling directions, the tooth width weighted based on the operating time ratio is similarly calculated.
For example, when the angle from the rolling direction is 0°, in FIG. are 5.40 [mm], 5.57 [mm], 5.64 [mm], 5.79 [mm] and 5.86 [mm]. By multiplying the optimum width of the teeth by the operating time ratios 20 [%], 45 [%], 20 [%], 10 [%], and 5 [%] corresponding to the torque ratios shown in FIG. Five values ​​of 108 [mm.%], 250.65 [mm.%], 112.8 [mm.%], 57.9 [mm.%], and 29.3 [mm.%] are calculated. . By adding the five values ​​and dividing by 100[%], the tooth width of 5.58[mm] weighted based on the operating time ratio is calculated at an angle of 0° from the rolling direction. Similarly, for angles of 22.5°, 45°, 67.5°, and 90° from the rolling direction, the tooth width weighted based on the operating time ratio is calculated.
[0046]
FIG. 11 is a table showing the tooth width weighted based on the ratio of the operating time shown in FIG. 10 for each angle from the rolling direction. In FIG. 10, the operating time ratio of the torque ratio of 30[%] to 50[%] is 45[%], which is the highest operating time ratio. Therefore, the width of the teeth weighted as shown in FIG. 11 is calculated to be close to the optimum width of the teeth when the torque ratio is 40[%] shown in FIG.
In this way, by designing the stator core by applying the tooth width weighted based on the operating time ratio, it is possible to reduce variations in the magnetic flux density throughout the operating time.
[0047]
Here, as shown in FIG. 11, a motor equipped with a stator core designed with a weighted tooth width is taken as an invention example, and a motor equipped with a stator core with a constant tooth width over the entire circumference is taken as a comparative example. The iron loss ratio is 0.993 when operated at a rotation speed of 3,000 [rpm] and at the operating time ratio shown in FIG. 10, and it was confirmed that the iron loss of 0.7 [%] can be suppressed. . In this way, iron loss can be suppressed by designing the stator core by applying the tooth width weighted based on the operating time ratio to configure the rotating electric machine.
[0048]
[Method of acquiring operation data]
In the above-described [first stator core design method], before designing the stator core, the operating condition having the highest operating time ratio among a plurality of operating conditions is specified in the rotating electrical machine having the stator core to be designed. There is a need. In addition, in the above-described [second stator core design method], before designing the stator core, it is necessary to specify the operating time ratio according to the operating conditions in the rotating electrical machine having the stator core to be designed.
That is, in both the first design method and the second design method, in order to design the stator core, it is necessary to acquire in advance operating data assuming that the rotating electric machine having the stator core to be designed operates. be.
[0049]
Here, the operational data is roughly divided into plan data and performance data.
Planned data is data in which the operation of the rotating electric machine is predetermined and the operating time is planned according to the operating conditions. For example, a rotating electrical machine used in a given production facility often continues a constant operation or repeats a constant operation. In such a rotary electric machine, plan data can be obtained in advance. By acquiring the plan data, it is possible to identify the information of the operating condition with the highest operating time ratio, or to specify the operating time ratio corresponding to the operating condition.
[0050]
On the other hand, actual data is data in which the same type of rotating electric machine is already operating and the operating time according to the operating conditions is accumulated as actual results. For example, rotating electric machines used in HEVs (Hybrid Electric Vehicles) and EVs (Electric Vehicles) cannot acquire plan data because the operating time differs depending on the user (driver) depending on the operating conditions. In such a case, performance data can be obtained in advance by collecting a huge amount of data on actual driving of the vehicle and analyzing the collected big data. For example, the data may be obtained by analyzing the driving time according to the driving conditions of the rotating electric machine when the vehicle is driven in the JC08 mode, which is the Japanese fuel consumption measurement standard. By acquiring the performance data, it is possible to specify the information of the operating condition with the highest operating time ratio, or to specify the operating time ratio corresponding to the operating condition.
[0051]
In this way, by acquiring the operating data from the planned data or the actual data, it is possible to identify the operating condition with the highest operating time ratio among a plurality of operating conditions before designing the stator core. It is possible to specify the ratio of driving time.
[0052]

Next, when the magnetic steel sheet is the material B and the stator core of the embedded permanent magnet type synchronous motor is designed, the above-mentioned "tooth width" x "tooth magnetic flux density" is substantially constant for each tooth. , an example of determining the width of the teeth. Note that the description of the same contents as the above-described will be omitted as appropriate.
Here, the relationship between the operating conditions (torque ratio) and the average magnetic flux density of the teeth when the rotation speed of the motor 400 shown in FIG. The results of the analysis for are the same as those in FIG.
From the average magnetic flux density of the teeth shown in FIG. 6, the average magnetic field intensity H [A/m] of the teeth is calculated. Next, based on the material properties of the material B, the magnetic flux density B[T] of the teeth for each angle from the rolling direction when the teeth are excited with the average magnetic field strength is calculated.
[0053]
FIG. 12 is a table showing the relationship between the torque ratio [%] and the tooth magnetic flux density B [T] for each angle from the rolling direction.
As shown in FIG. 12, at torque ratios of 20[%], 40[%], 60[%], and 80[%], variations occur in the magnetic flux density of the teeth for each angle from the rolling direction. Further, when the torque ratio is 20[%], 40[%], 60[%], and 80[%], the magnetic flux density of the teeth at an angle of 45° from the rolling direction is large, and the teeth at angles of 0° and 90° from the rolling direction ° Teeth magnetic flux density is small. Such a tendency is combined with the tendency that the B50 ratio is large at an angle of 45° from the rolling direction and the B50 ratio is small at angles of 0° and 90° from the rolling direction, as shown in the graph 202 of material B shown in FIG. I am doing it. On the other hand, as shown in FIG. 12, when the torque ratio is 100[%], magnetic saturation occurs, so the magnetic flux density of the teeth is constant regardless of the angle from the rolling direction.
Next, based on the magnetic flux density of the teeth for each angle from the rolling direction shown in FIG. 12, the width of the teeth is determined so that "the width of the teeth" x "the magnetic flux density of the teeth" is substantially constant for each tooth. do.
[0054]
FIG. 13 is a table showing the relationship between the torque ratio [%] and the optimum tooth width [mm] determined for each angle from the rolling direction. A stator core is designed by applying the determined optimal tooth width to the tooth width corresponding to the angle from the rolling direction.
In this way, in the stator core designed, the width of the teeth along the direction with excellent magnetic properties is narrower than the width of the teeth along the directions with poor magnetic properties. In Material B, the teeth along the direction with excellent magnetic properties are the teeth along the angle of 45° from the rolling direction, and the teeth along the angles of 135°, 225°, and 315° from the rolling direction. It is not limited, and also includes teeth located in the vicinity of these teeth. Specifically, in material B, the teeth along the direction in which the magnetic properties are inferior are the teeth included in the angles 33.75° to 56.25°, the teeth included in the angles 123.75° to 146.25°, and the teeth included in the angles The teeth included in the angles 213.75° to 236.25° and the teeth included in the angles 303.75° to 326.25°.
In addition, in the material B, the teeth along the direction of inferior magnetic properties are not limited to the teeth along the angles of 0° and 90° from the rolling direction, but also include teeth located in the vicinity of these teeth. . Specifically, in material B, the teeth along the direction with excellent magnetic properties are the teeth included in the angles 348.75° to 11.25°, the teeth included in the angles 168.75° to 191.25°, and the teeth included in the angles The teeth included in the angles of 78.75° to 101.25° and the teeth included in the angles of 258.75° to 281.25°.
[0055]
FIG. 14 is a table showing the relationship between the iron loss ratio [-] between a stator core designed with an optimum tooth width and a stator core with a constant tooth width over the entire circumference for each torque ratio [%]. be.
From the results of the iron loss ratio shown in FIG. 14, the iron loss of 0.6 [%] to 6.4 [%] is suppressed at torque ratios of 20 [%], 40 [%], 60 [%], and 80 [%]. I was able to confirm that it is possible. On the other hand, at a torque ratio of 100[%], the magnetic saturation occurred and the magnetic flux density of the teeth was constant regardless of the angle from the rolling direction, so the effect of suppressing iron loss could not be confirmed.
In this way, depending on operating conditions such as the torque ratio, it is possible to reduce variations in the magnetic flux density by determining the tooth width so that the "tooth width" x "magnetic flux density of the teeth" is approximately constant for each tooth. , it was confirmed that iron loss can be suppressed in the region where magnetic saturation does not occur.
[0056]
Next, similar to the [second stator core design method] described above, the optimum tooth width for each angle from the rolling direction is weighted based on the operating time ratio corresponding to the torque ratio shown in FIG.
FIG. 15 is a table showing the tooth width weighted based on the ratio of the operating time shown in FIG. 10 for each angle from the rolling direction.
Here, a motor with a stator core designed with weighted tooth widths as shown in FIG. 15 is taken as an invention example, and a motor with a stator core with a constant tooth width over the entire circumference is taken as a comparative example. The iron loss ratio is 0.958 when operated at a rotation speed of 3,000 [rpm] and at the operating time ratio shown in FIG.It could be confirmed.
[0057]

Next, when an electromagnetic steel sheet is material A and a stator core for an induction motor is designed, the width of the teeth is determined so that the above-mentioned "width of the teeth" x "magnetic flux density of the teeth" is substantially constant for each tooth. An example of doing so will be described. Note that the description of the same contents as the above-described will be omitted as appropriate. In the induction motor, the teeth of the stator core are parallel along the radial direction as shown in FIG. 3(a).
FIG. 16 is a diagram showing an example of the configuration of the motor 1600 before determining the width of the teeth, ie, the width of each tooth is constant over the entire circumference. 16 shows a cross section of the motor 1600 taken perpendicular to its axis O. FIG.
In FIG. 16, motor 1600 is an induction motor and has rotor 1610 and stator 1620 .
The rotor 1610 is attached to the rotating shaft 1630 so as to be coaxial with the rotating shaft 1630 (axis O). Rotor 1610 has a plurality of coils. As shown in FIG. 16, motor 1600 has four poles. Also, the outer diameter of the rotor 1610 is 134 [mm].
The stator 1620 has a stator core 1621 and coils 1622 . The outer diameter of stator 1620 is 220 [mm], and the inner diameter of stator 1620 is 136 [mm]. The stator core 1621 has 60 slots. Also, the coil 1622 is a distributed winding.
[0058]
FIG. 17 is an enlarged view of a portion of the stator core 1621 of FIG. 16 at an angle of 0° to 90° from the rolling direction. Here, among the teeth 1701a to 1701p of the stator core 1621, the tooth 1701a is positioned at an angle of 0° from the rolling direction, and the 1/2 width of the tooth is omitted. Among the teeth 1701a to 1701p, the tooth 1701p is positioned at an angle of 90° from the rolling direction, and the 1/2 width of the tooth is omitted in the drawing. Moreover, each tooth has a parallel shape along the radial direction as shown in FIG. 3(a). The width of each tooth is 4 mm.
[0059]
Here, the result of analyzing the relationship between the operating conditions (torque ratio) and the average magnetic flux density of the teeth when the rotation speed of the motor 1600 is 3,000 [rpm] and the width of the teeth is constant over the entire circumference of the stator core 1621. is shown in FIG.
FIG. 18 is a diagram showing the relationship between the torque ratio [%], which is the operating condition of the motor 1600, and the average magnetic flux density B [Tpeak] of the teeth.
From the average magnetic flux density of the teeth shown in FIG. 18, the average magnetic field intensity H [A/m] of the teeth is calculated. Next, based on the material properties of the material A, the magnetic flux density B[T] of the teeth for each angle from the rolling direction when the teeth are excited with the average magnetic field strength is calculated.
[0060]
FIG. 19 is a table showing the relationship between the torque ratio [%] and the magnetic flux density B [T] of the teeth for each angle from the rolling direction.
As shown in FIG. 19, at torque ratios of 20[%], 40[%], 60[%], and 80[%], variations occur in the magnetic flux density of the teeth for each angle from the rolling direction. Further, when the torque ratio is 40 [%], 60 [%], and 80 [%], the magnetic flux density of the teeth at angles of 0° and 90° from the rolling direction is large, and the magnetic flux of the teeth at an angle of 45° from the rolling direction is large. low density; Such a tendency is consistent with the tendency that the B50 ratio is large at an angle of 0° and 90° from the rolling direction, and the B50 ratio is small at an angle of 45° from the rolling direction, as shown in the graph 201 for material A shown in FIG. I am doing it. On the other hand, as shown in FIG. 19, when the torque ratio is 100[%], the teeth are magnetically saturated, so the magnetic flux density of the teeth is substantially constant regardless of the angle from the rolling direction.
Next, based on the magnetic flux density of the teeth for each angle from the rolling direction shown in FIG. 19, the width of the teeth is determined so that "the width of the teeth" x "the magnetic flux density of the teeth" is substantially constant for each tooth. do.
[0061]
FIG. 20 is a table showing the relationship between the torque ratio [%] and the optimum tooth width [mm] determined for each angle from the rolling direction.
For example, in FIG. 20, taking the case of a torque ratio of 60 [%] as an example, when the angle from the rolling direction is 0°, the optimum width of the teeth is 3.85 [mm], and when the angle is 22.5°, the optimum width of the teeth is 3.85 [mm]. 96 [mm], optimum tooth width 4.08 [mm] at angle 45°, optimum tooth width 4.06 [mm] at angle 67.5°, optimum tooth width 3.96 [mm] at angle 90° ]. Here, the "magnetic flux density of the teeth" in the case of the torque ratio of 60 [%] in FIG. 19 and the "optimum width of the teeth" in the case of the torque ratio of 60 [%] in FIG. The multiplied products are all 6.7, which is substantially constant.
[0062]
The stator core is designed by applying the optimal tooth width determined in this way to the tooth width according to the angle from the rolling direction.
For example, in FIG. 20, taking the torque ratio of 60 [%] as an example, the width of teeth 1701a to 1701b included in the 0° range (A1) shown in FIG. The width of the teeth 1701c to 1701f included in the range (A2) is 3.96 [mm], the width of the teeth 1701g to 1701j included in the 45° range (A3) is 4.08 [mm], and the 67.5° range ( The width of the teeth 1701k to 1701n included in A4) is designed to be 4.06 [mm], and the width of the teeth 1701o to 1701p included in the 90° range (A5) is designed to be 3.96 [mm].
[0063]
Further, the magnetic flux density B [T] of the tooth for each angle from the rolling direction shown in FIG. Since the angles 168.75° to 191.25° shown in 16 are also substantially the same, the teeth included in the angles 168.75° to 191.25° are also approximately the width of the teeth included in the 0° range (A1). Design to the same width.
Similarly, the teeth included in the angles 146.25° to 168.75°, 191.25° to 213.75°, and 326.25° to 348.75° shown in FIG. 16 are also in the 22.5° range (A2). The width is designed to be substantially the same as the width of the teeth included in the .
Similarly, the teeth included in the angles 123.75° to 146.25°, 213.75° to 236.25°, and 303.75° to 326.25° shown in FIG. ° to 56.25°: The width is designed to be substantially the same as the width of the teeth included in A3).
Similarly, the teeth included in the angles 101.25° to 123.75°, 236.25° to 258.75°, and 281.25° to 303.75° shown in FIG. .25° to 78.75°: The width is designed to be substantially the same as the width of the teeth included in A4).
Similarly, the teeth included in the angles 258.75° to 281.25° shown in FIG. design.
Although the tooth 1701c positioned between the 0° range (A1) and the 22.5° range (A2) is set to the 22.5° range, it may be set to the 0° range. Also, the tooth 1701n positioned at the boundary between the 67.5° range (A4) and the 90° range (A5) is set to the 67.5° range, but may be set to the 90° range.
[0064]
FIG. 21 is a table showing the relationship between the iron loss ratio [-] between a stator core designed with an optimum tooth width and a stator core with a constant tooth width over the entire circumference for each torque ratio [%]. be.
From the results of the iron loss ratio shown in FIG. 21, the iron loss of 0.1 [%] to 1.4 [%] is suppressed at torque ratios of 20 [%], 40 [%], 60 [%], and 80 [%]. I was able to confirm that it is possible. On the other hand, at a torque ratio of 100[%], magnetic saturation occurred, and the magnetic flux density of the teeth was substantially constant regardless of the angle from the rolling direction, so the effect of suppressing iron loss could not be confirmed.
[0065]
Next, similar to the [second stator core design method] described above, the optimum tooth width for each angle from the rolling direction is weighted based on the operating time ratio corresponding to the torque ratio shown in FIG.
FIG. 22 is a table showing the tooth width weighted based on the ratio of the operating time shown in FIG. 10 for each angle from the rolling direction.
Here, as shown in FIG. 22, a motor equipped with a stator core designed with a weighted tooth width was taken as an invention example, and a motor equipped with a stator core with a constant tooth width over the entire circumference was taken as a comparative example. The iron loss ratio is 0.995 when operated at a rotation speed of 3,000 [rpm] and at the operating time ratio shown in FIG. 10, and it was confirmed that the iron loss of 0.5 [%] can be suppressed. .
[0066]

Next, when the magnetic steel sheet is the material B and the stator core of the induction motor is designed, the width of the teeth is adjusted so that the above-mentioned "width of the teeth" x "magnetic flux density of the teeth" is substantially constant for each tooth. An example of determination will be described. Note that the description of the same content as the above-described will be omitted as appropriate.
Here, the relationship between the operating conditions (torque ratio) and the average magnetic flux density of the teeth when the rotation speed of the motor 1600 shown in FIG. The results of the analysis for are the same as in FIG. 18 .
From the average magnetic flux density of the teeth shown in FIG. 18, the average magnetic field intensity H [A/m] of the teeth is calculated. Next, based on the material properties of the material B, the magnetic flux density B[T] of the teeth for each angle from the rolling direction when the teeth are excited with the average magnetic field strength is calculated.
[0067]
FIG. 23 is a table showing the relationship between the torque ratio [%] and the tooth magnetic flux density B [T] for each angle from the rolling direction.
As shown in FIG. 23, the magnetic flux density of the teeth varies for each angle from the rolling direction regardless of the torque ratio. Moreover, in any torque ratio, the magnetic flux density of the teeth at an angle of 45° from the rolling direction is large, and the magnetic flux density of the teeth at angles of 0° and 90° from the rolling direction is small. Such a tendency is combined with the tendency that the B50 ratio is large at an angle of 45° from the rolling direction and the B50 ratio is small at angles of 0° and 90° from the rolling direction, as shown in the graph 202 of material B shown in FIG. I am doing it.
Next, based on the magnetic flux density of the teeth for each angle from the rolling direction shown in FIG. 23, the width of the teeth is determined so that "width of teeth" x "magnetic flux density of teeth" is substantially constant for each tooth. do.
[0068]
FIG. 24 is a table showing the relationship between the torque ratio [%] and the optimum tooth width [mm] determined for each angle from the rolling direction.
FIG. 25 is a table showing the relationship between the iron loss ratio [-] between a stator core designed with an optimum tooth width and a stator core with a constant tooth width over the entire circumference for each torque ratio [%]. be.
From the results of the iron loss ratio shown in FIG. 25, the iron loss of 1.1 [%] to 5.6 [%] is suppressed at torque ratios of 20 [%], 40 [%], 60 [%], and 80 [%]. I was able to confirm that it is possible. On the other hand, at a torque ratio of 100[%], magnetic saturation occurred, and the magnetic flux density of the teeth was substantially constant regardless of the angle from the rolling direction, so the effect of suppressing iron loss could not be confirmed.
In this way, depending on operating conditions such as torque ratio, the width of each tooth is determined so that the "tooth width" x "magnetic flux density of teeth" is approximately constant for each tooth, thereby reducing variations in magnetic flux density. It was confirmed that iron loss can be suppressed in the region where magnetic saturation does not occur.
[0069]
Next, similar to the [second stator core design method] described above, the optimum tooth width for each angle from the rolling direction is weighted based on the operating time ratio corresponding to the torque ratio shown in FIG.
Fig. 26 shows the rolling methodFIG. 11 is a table showing tooth width weighted based on the ratio of operating time shown in FIG. 10 for each angle from the direction;
Here, as shown in FIG. 26, a motor equipped with a stator core designed with a weighted tooth width was taken as an invention example, and a motor equipped with a stator core with a constant tooth width over the entire circumference was taken as a comparative example. The iron loss ratio is 0.972 when operated at a rotation speed of 3,000 [rpm] and the operating time ratio shown in FIG. 10, and it was confirmed that the iron loss of 2.8 [%] can be suppressed. .
[0070]

Next, a case will be described in which the above-described [first stator core design method] and [second stator core design method] are performed using the stator core design apparatus 2700 . The hardware of the stator core design device 2700 is realized by using, for example, an information processing device having a CPU, ROM, RAM, HDD and various hardware, or by using dedicated hardware.
[0071]
FIG. 27 is a diagram showing an example of a mechanical configuration of a stator core design device 2700. FIG.
The stator core design device 2700 includes an operation data acquisition unit 2701, an operation condition/operation ratio identification unit 2702, an average magnetic flux density acquisition unit 2703, an evaluation magnetic flux density calculation unit 2704, an average magnetic field strength calculation unit 2705, It has a tooth magnetic flux density acquisition section 2706 , a tooth width determination section 2707 and a stator core design section 2708 .
[0072]
FIG. 28 is a flow chart showing an example of processing of the stator core design device 2700 . The flowchart of FIG. 28 shows an example of realizing the above-described [first stator core design method] by a stator core design device 2700 . Descriptions similar to those described above are omitted as appropriate.
In S101, the operating data acquisition unit 2701 acquires operating data of the rotating electrical machine when operating the rotating electrical machine having the stator core to be designed. That is, the operating data acquisition unit 2701 acquires operating data assuming that the rotating electric machine having the stator core to be designed operates.
As mentioned above, operational data includes planned data and actual data. The operation data acquisition unit 2701 acquires plan data in the case of a rotating electric machine whose operation is predetermined, and acquires performance data in the case where the rotating electric machine of the same type is already operating and has been accumulated as a result. . The operation data acquisition unit 2710 may acquire at least one of the plan data and the performance data, without being limited to the operation data of the plan data or the performance data. For example, the operation data shown in FIG. 10 is acquired by the process of S101.
[0073]
In S102, the operating condition/operating ratio identification unit 2702 identifies the operating condition with the highest operating time ratio among the plurality of operating conditions based on the operating data acquired in S101. By the processing of S102, for example, based on the operating data shown in FIG. 10, a torque ratio of 30[%] to 50[%], that is, a torque ratio of 40[%] is specified as the operating condition with the highest operating time ratio. .
[0074]
At S103, the average magnetic flux density acquisition unit 2703 acquires information on the average magnetic flux density of the teeth corresponding to the operating conditions specified at S102. Specifically, the average magnetic flux density acquisition unit 2703 performs an electromagnetic field analysis (numerical analysis) based on Maxwell's equations under the operating conditions specified in S102 and when the tooth width is constant over the entire circumference of the stator core. Alternatively, the average magnetic flux density of the teeth is obtained by measuring the induced voltage using a search coil and integrating the induced voltage.
By the processing of S103, for example, like the relationship between the torque ratio and the average magnetic flux density of the teeth shown in FIG. A density of 1.44 [T peak] is obtained.
[0075]
In S104, the average magnetic field intensity calculation unit 2705 calculates the average magnetic field intensity of the teeth from the information of the average magnetic flux density of the teeth acquired in S103. The average magnetic field intensity of the teeth can be calculated based on the relative magnetic permeability of the magnetic steel sheet.
[0076]
In S105, the tooth magnetic flux density acquisition unit 2706 acquires information on the magnetic flux density of the teeth when excited with the average magnetic field intensity of the teeth calculated in S104. Specifically, the teeth magnetic flux density acquisition unit 2706 obtains the magnetic flux density B[T] of the teeth for each angle from the rolling direction when the teeth are excited at the average magnetic field strength, and obtained based on the BH characteristics for each angle from the rolling direction.
By the processing of S105, for example, at the torque ratio of 40 [%], which is the operating condition with the highest operating time ratio shown in FIG. , 90°, magnetic flux densities of the teeth of 1.51 [T], 1.47 [T], 1.42 [T], 1.42 [T] and 1.44 [T] are obtained.
[0077]
In S106, the tooth width determination unit 2707 determines the width of the teeth so that the product of the "width of the teeth" and the "magnetic flux density of the teeth" obtained in S105 is substantially constant for each tooth. The width of the teeth thus determined is the optimum width of the teeth.
By the process of S106, for example, as shown in FIG. 8, at a torque ratio of 40 [%], which is the operating condition with the highest operating time ratio, the angles 0°, 22.5°, 45°, 67° from the rolling direction Optimum tooth widths of 5.57 [mm], 5.72 [mm], 5.95 [mm], 5.93 [mm], and 5.85 [mm] are determined at 5° and 90°, respectively. .
[0078]
In S107, the stator core design unit 2708 applies the determined optimal tooth width to the tooth width corresponding to the angle from the rolling direction to design the stator core.
By the processing of S107, for example, the optimum widths of the teeth at angles of 0°, 22.5°, 45°, 67.5°, and 90° from the rolling direction are set to the 0° range (two A1) shown in FIG. , 22.5° range (4 A2), 45° range (4 A3), 67.5° range (4 A4), 90° range (2 A5), respectively. A starter core is designed.
[0079]
By designing the stator core using the stator core design device 2700 in this way, it is possible to reduce variations in the magnetic flux density and suppress iron loss under the operating condition with the highest operating time ratio.
In the above description, in S102, the operating condition with the highest operating time ratio is specified among the plurality of operating conditions, in S103, information on the average magnetic flux density of the teeth corresponding to the specified operating condition is acquired, and in S104 Although the case where the strength of the average magnetic field of the teeth is calculated from the information of the average magnetic flux density of the teeth has been described above, the present invention is not limited to this case. For example, by omitting the processing from S101 to S104 and the operator of the stator core designing device 2700 inputs a predetermined magnetic field strength, the teeth magnetic flux density acquisition unit 2706 of the stator core designing device 2700 obtains the average magnetic field of the teeth. information on the strength of In this case, in S105, the tooth magnetic flux density acquisition unit 2706 acquires the input information about the average magnetic field strength of the teeth, and calculates the magnetic flux density of the teeth from the obtained information about the average magnetic field strength of the teeth. can be obtained.
[0080]
FIG. 29 is a flow chart showing an example of processing of the stator core design device 2700 . The flowchart of FIG. 29 shows an example of realizing the above-described [second stator core design method] by a stator core design device 2700 . It should be noted that descriptions of processes similar to those in the flowchart of FIG. 28 will be omitted as appropriate.
[0081]
In S201, the operating data acquisition unit 2701 acquires the operating data of the rotating electrical machine when operating the rotating electrical machine having the stator core to be designed. This process is the same as the process of S101. For example, the operation data shown in FIG. 10 is acquired by the process of S201.
In S202, the operating condition/operating ratio identification unit 2702 identifies the operating time ratio for each of a plurality of operating conditions based on the operating data acquired in S101. By the process of S202, for example, the operating time ratio corresponding to the torque ratio is specified based on the operating data shown in FIG.
[0082]
In S203, the average magnetic flux density acquisition unit 2703 acquires information on the average magnetic flux density of the teeth corresponding to each of a plurality of operating conditions. Specifically, the average magnetic flux density acquisition unit 2703 performs electromagnetic field analysis (numerical analysis) based on Maxwell's equations when the tooth width is constant over the entire circumference of the stator core for each of a plurality of operating conditions, By measuring the induced voltage using and integrating the induced voltage, the average magnetic flux density of the teeth is obtained for each of a plurality of operating conditions.
By the processing of S203, the average magnetic flux density of the teeth is acquired for each torque ratio, for example, like the relationship between the torque ratio and the average magnetic flux density of the teeth shown in FIG.
[0083]
In S204, the average magnetic field intensity calculation unit 2705 calculates the average magnetic field intensity of the teeth for each of the plurality of operating conditions from the information on the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions acquired in S203. calculate. The average magnetic field intensity of the teeth can be calculated based on the relative magnetic permeability of the magnetic steel sheet.
[0084]
In S205, the tooth magnetic flux density acquisition unit 2706 acquires information on the magnetic flux density of the teeth for each of the plurality of operating conditions when the teeth are excited with the average magnetic field intensity for each of the plurality of operating conditions calculated in S204. . Specifically, the teeth magnetic flux density acquisition unit 2706 obtains the magnetic flux density B [T] of the teeth for each angle from the rolling direction when the teeth are excited at the average magnetic field strength for each of a plurality of operating conditions. It is acquired based on the characteristics, more specifically, the BH characteristics for each angle from the rolling direction of the electrical steel sheet.
By the processing of S205, for example, as shown in FIG. 7, the magnetic flux density of the teeth is obtained at angles of 0°, 22.5°, 45°, 67.5°, and 90° from the rolling direction for each torque ratio. be done.
[0085]
In S206, the tooth width determination unit 2707 determines the width of the teeth for each of the plurality of operating conditions so that the product of the "width of the teeth" and the "magnetic flux density of the teeth" obtained in S205 is substantially constant for each tooth. Calculate width. The width of the teeth calculated in this manner is the optimum width of the teeth.
By the process of S206, for example, as shown in FIG. 8, the optimum tooth width is calculated at angles of 0°, 22.5°, 45°, 67.5°, and 90° from the rolling direction for each torque ratio. be done.
[0086]
In S207, the tooth width determination unit 2707 weights the optimum tooth width for each of the plurality of operating conditions calculated in S206 based on the operating time ratio for each of the plurality of operating conditions specified in S202. Determines the width of the trailing teeth.
By the processing of S207, for example, as shown in FIG. 11, the tooth width weighted based on the operating time ratio is determined.
[0087]
In S208, the stator core design unit 2708 designs the stator core by applying the weighted tooth width to the tooth width corresponding to the angle from the rolling direction.
By the processing of S208, for example, the widths of the teeth weighted at angles of 0°, 22.5°, 45°, 67.5°, and 90° from the rolling direction are adjusted to the 0° range (two A1 ), 22.5° range (4 A2), 45° range (4 A3), 67.5° range (4 A4), 90° range (2 A5). Let the starter core be designed.
By designing the stator core using the stator core designing device 2700 in this way, it is possible to reduce variations in the magnetic flux density throughout the operating time and suppress iron loss.
[0088]
note thatIn the flowchart of FIG. 29, in S207, the optimum tooth width for each of the plurality of operating conditions is weighted based on the operating time ratio for each of the plurality of operating conditions. However, the present invention is not limited to this case.
FIG. 30 is a flow chart showing an example of processing of the stator core design device 2700 . The flowchart of FIG. 30 shows an example of implementing a method different from the [second stator core design method] described above by a stator core design device 2700 . 28 and 29 will be omitted as appropriate.
[0089]
In S301, the operating data acquisition unit 2701 acquires the operating data of the rotating electrical machine when operating the rotating electrical machine having the stator core to be designed. This process is similar to the processes of S101 and S201. For example, the operation data shown in FIG. 10 is acquired by the process of S301.
In S302, the operating condition/operating ratio identification unit 2702 identifies the operating time ratio for each of a plurality of operating conditions based on the operating data acquired in S301. This process is the same as the process of S202.
[0090]
In S303, the average magnetic flux density acquisition unit 2703 acquires information on the average magnetic flux density of the teeth corresponding to each of a plurality of operating conditions. This process is the same process as S203. By the processing of S303, for example, the average magnetic flux density of the teeth is obtained for each torque ratio, like the relationship between the torque ratio and the average magnetic flux density of the teeth shown in FIG.
[0091]
In S304, the evaluation magnetic flux density calculation unit 2704 calculates the weighted evaluation of the teeth based on the operating time ratio specified in S302 from the information on the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions acquired in S303. Calculate the magnetic flux density. The evaluation magnetic flux density is the magnetic flux density of the teeth obtained by weighting the average magnetic flux density of the teeth based on the operating time ratio. Specifically, the evaluation magnetic flux density calculation unit 2704 calculates the evaluation magnetic flux density by multiplying the average magnetic flux density of the teeth by the operating time ratio for each torque ratio, adding the multiplied values, and dividing by 100. be able to.
For example, in the case of the relationship between the torque ratio and the average magnetic flux density of the teeth as shown in FIG. 6, and the operating data as shown in FIG. ] is (1.22 [T peak] x 20 [%] + 1.44 [T peak] x 45 [%] + 1.59 [T peak] x 20 [%] + 1.82 [T peak] x 10 [ %]+2.04[T peak]×5[%]) divided by 100.
[0092]
In S305, the average magnetic field strength calculator 2705 calculates the average magnetic field strength of the teeth from the evaluated magnetic flux density of the teeth calculated in S304. The average magnetic field intensity of the teeth can be calculated based on the relative magnetic permeability of the magnetic steel sheet.
In S306, the tooth magnetic flux density acquisition unit 2706 acquires information on the magnetic flux density of the teeth when excited with the average magnetic field intensity of the teeth calculated in S305. This process is the same process as S105.
[0093]
In S307, the tooth width determination unit 2707 determines the width of the teeth so that the product of the "width of the teeth" and the "magnetic flux density of the teeth" acquired in S306 is substantially constant for each tooth. This process is similar to S106.
By the processing of S307, for example, as shown in FIG. 11, the tooth width weighted based on the operating time ratio is determined.
[0094]
In S308, the stator core design unit 2708 designs the stator core by applying the determined tooth width to the tooth width according to the angle from the rolling direction. This process is the same process as S107.
By designing the stator core using the stator core designing device 2700 in this way, it is possible to reduce variations in the magnetic flux density throughout the operating time and suppress iron loss. In addition, the evaluation magnetic flux density of the teeth is calculated by weighting the average magnetic flux density of the teeth based on the ratio of the operating time, and the subsequent processing is performed based on the calculated evaluation magnetic flux density of the teeth, thereby reducing the processing. be able to.
[0095]
As described above, according to the present embodiment, the width of the teeth is determined so that the "tooth width" x "the magnetic flux density of the teeth" is substantially constant for each tooth, thereby reducing variations in the magnetic flux density. Therefore, iron loss can be suppressed.
In addition, as described above, each tooth may be teeth at predetermined intervals such as angles of 0°, 22.5°, 45°, 67.5°, and 90° from the rolling direction. , may be all teeth. Further, "substantially constant" is not limited to the case of being completely constant, but includes the range in which the iron loss can be suppressed more than in the comparative example. Specifically, the term “substantially constant” means that the difference between the maximum value and the minimum value of “tooth width”דtooth magnetic flux density” is within ±1%, preferably within ±0.5%. As described above, the "magnetic flux density of the teeth" in the case of the torque ratio of 60 [%] in FIG. 7 and the "optimum width of the teeth" in the case of the torque ratio of 60 [%] in FIG. It has been described that the product of each multiplication is 9.3 and is substantially constant. Specifically, when the angle from the rolling direction is 0°, the magnetic flux density of the teeth is 1.65 [T]×the optimal width of the teeth is 5.64 [mm]=9.306≈9.3, and the angle from the rolling direction is 22.5 mm. At 5°, the magnetic flux density of the teeth is 1.61 [T] × the optimum width of the teeth is 5.76 [mm] = 9.2736 ≈ 9.3. At an angle of 45° from the rolling direction, the magnetic flux density of the teeth is 1.55 [T]. ] × optimal width of teeth 5.99 [mm] = 9.2845 ≈ 9.3, magnetic flux density of teeth 1.56 [T] × optimal width of teeth 5.96 [ mm] = 9.2976 ≈ 9.3, and at an angle of 90° from the rolling direction, the magnetic flux density of the tooth 1.59 [T] x the optimum tooth width 5.85 [mm] = 9.3015 ≈ 9.3 . Since the difference between the maximum value and the minimum value in this case is 9.306÷9.2736≈1.0035, the approximately constant is within 0.5%. Also, if 9.25 to 9.34 are allowed as the range of rounding off of 9.3, 9.34÷9.25≈1.0097, so the approximate constant is within 1%.
[0096]
Next, among the above-described electromagnetic steel sheets, material B can suppress iron loss more than material A.
Here, the electromagnetic steel sheet related to material B will be described.
In the following description, a direction with an angle of 45° from the rolling direction is called a direction inclined by 45° from the rolling direction, and a direction with an angle of 135° from the rolling direction is called a direction inclined by 135° from the rolling direction. called. In addition, a direction with an angle of θ° from the rolling direction is referred to as a direction inclined by θ° from the rolling direction. Thus, the direction of the angle θ° from the rolling direction and the direction inclined by θ° from the rolling direction have the same meaning.
[0097]
First, the chemical composition of the non-oriented electrical steel sheet (hereinafter referred to as the non-oriented electrical steel sheet of the present embodiment), which is an example of the electrical steel sheet related to material B, and the steel material used in the manufacturing method thereof will be described. In the following description, "%", which is the unit of content of each element contained in the non-oriented electrical steel sheet or steel material of the present embodiment, means "% by mass" unless otherwise specified. In addition, the numerical limits described between "-" include the lower limit and the upper limit. Any numerical value indicated as "less than" or "greater than" excludes that value from the numerical range. Non-oriented electrical steel sheets and steel materials have a chemical composition that can cause ferrite-austenite transformation (hereinafter, α-γ transformation), and are C: 0.0100% or less, Si: 1.50% to 4.00%, sol. Al: 0.0001% to 1.0%, S: 0.0100% or less, N: 0.0100% or less, one or more selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au : 2.50% to 5.00% in total, Sn: 0.000% to 0.400%, Sb: 0.000% to 0.400%, P: 0.000% to 0.400%, and One or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total, the balance being Fe and impurities It has a chemical composition consisting of Furthermore, Mn, Ni, Co, Pt, Pb, Cu, Au, Si and sol. The content of Al satisfies the predetermined condition described later. Examples of impurities include those contained in raw materials such as ores and scraps, and those contained in manufacturing processes.
[0098]
<>
C increases iron loss and causes magnetic aging. Therefore, the lower the C content, the better. Such a phenomenon is remarkable when the C content exceeds 0.0100%. Therefore, the C content should be 0.0100% or less. A reduction in the C content also contributes to the uniform improvement of the magnetic properties in all directions within the plate surface. Although the lower limit of the C content is not particularly limited, it is preferably 0.0005% or more in consideration of the cost of decarburization treatment during refining.
[0099]
<>
Si increases electrical resistance, reduces eddy current loss, reduces iron loss, and increases yield ratio to improve punching workability for iron cores. If the Si content is less than 1.50%, these effects cannot be sufficiently obtained. Therefore, the Si content should be 1.50% or more. On the other hand, if the Si content exceeds 4.00%, the magnetic flux density is lowered, the punching workability is lowered due to an excessive increase in hardness, and cold rolling becomes difficult. Therefore, the Si content should be 4.00% or less.
[0100]
<>
sol. Al increases electrical resistance, reduces eddy current loss, and reduces iron loss. sol. Al also contributes to improving the relative magnitude of the magnetic flux density B50 with respect to the saturation magnetic flux density. Here, the magnetic flux density B50 is the magnetic flux density when excited with a magnetic field strength of 5000 A/m. sol. If the Al content is less than 0.0001%, these effects cannot be sufficiently obtained. Al also has the effect of promoting desulfurization in steelmaking. Therefore, sol. Al content shall be 0.0001% or more. On the other hand, sol. If the Al content exceeds 1.0%, the magnetic flux density is lowered, the yield ratio is lowered, and the punching workability is lowered. Therefore, sol. Al content is 1.0% or less.
[0101]
<>
S is not an essential element, but is contained as an impurity in steel, for example. S inhibits recrystallization and grain growth during annealing due to the precipitation of fine MnS. Therefore, the lower the S content, the better. The increase in iron loss and the decrease in magnetic flux density due to the inhibition of recrystallization and grain growth are remarkable when the S content exceeds 0.0100%. Therefore, the S content is set to 0.0100% or less. Although the lower limit of the S content is not particularly limited, it is preferably 0.0003% or more in consideration of the cost of desulfurization treatment during refining.
[0102]
<>
As with C, N degrades the magnetic properties, so the lower the N content, the better. Therefore, the N content should be 0.0100% or less. Although the lower limit of the N content is not particularly limited, it is preferably 0.0010% or more in consideration of the cost of denitrification treatment during refining.
[0103]
<>
Since these elements are elements necessary for causing α-γ transformation, it is necessary to contain 2.50% or more of these elements in total. On the other hand, if the total content exceeds 5.00%, the cost increases and the magnetic flux density may decrease. Therefore, the total content of these elements is set to 5.00% or less.
[0104]
In addition, it is assumed that the following conditions are satisfied as conditions under which α-γ transformation can occur. That is, the Mn content (% by mass) is [Mn], Ni content (mass%) [Ni], Co content (mass%) [Co], Pt content (mass%) [Pt], Pb content (mass%) [Pb], Cu The content (% by mass) is [Cu], the Au content (% by mass) is [Au], the Si content (% by mass) is [Si], sol. The Al content (% by mass) is measured as [sol. Al], it is preferable that the following formula (1) is satisfied in terms of % by mass.
([Mn] + [Ni] + [Co] + [Pt] + [Pb] + [Cu] + [Au]) - ([Si] + [sol. Al]) > 0% (1)
[0105]
If the above formula (1) is not satisfied, the α-γ transformation does not occur, resulting in a low magnetic flux density.
[0106]
<>
Sn and Sb improve the texture after cold rolling and recrystallization, and improve the magnetic flux density. Therefore, these elements may be contained as necessary, but if contained excessively, they embrittle the steel. Therefore, both Sn content and Sb content are set to 0.400% or less. Also, P may be contained in order to ensure the hardness of the steel sheet after recrystallization, but if contained excessively, it causes the embrittlement of the steel. Therefore, the P content should be 0.400% or less. In the case of imparting further effects such as magnetic properties as described above, 0.020% to 0.400% Sn, 0.020% to 0.400% Sb, and 0.020% to 0.400% % of one or more selected from the group consisting of P.
[0107]
<>
　Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn and Cd react with S in molten steel during casting to form sulfide or oxysulfide or both precipitates. Hereinafter, Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn and Cd may be collectively referred to as "coarse precipitate forming elements". The grain size of coarse precipitate-forming elements is about 1 μm to 2 μm, which is much larger than the grain size (about 100 nm) of fine precipitates such as MnS, TiN and AlN. For this reason, these fine precipitates adhere to the precipitates of the coarse precipitate-forming element and are less likely to hinder recrystallization and grain growth during intermediate annealing. In order to sufficiently obtain these effects, the total content of these elements is preferably 0.0005% or more. However, if the total amount of these elements exceeds 0.0100%, the total amount of sulfides or oxysulfides or both becomes excessive, which inhibits recrystallization and grain growth during intermediate annealing. Therefore, the total content of coarse precipitate-forming elements is set to 0.0100% or less.
[0108]
<>
Next, the texture of the non-oriented electrical steel sheet of this embodiment will be described. Although the details of the manufacturing method will be described later, the non-oriented electrical steel sheet of the present embodiment has a chemical composition that can cause α-γ transformation, and the structure is refined by rapid cooling immediately after the finish rolling in hot rolling. It becomes a structure in which {100} crystal grains grow. As a result, the non-oriented electrical steel sheet of this embodiment has an integrated strength of 5 to 30 in the {100}<011> orientation, and the magnetic flux density B50 in the direction of 45° to the rolling direction is particularly high. Thus, although the magnetic flux density is high in a specific direction, a high magnetic flux density is obtained on average in all directions as a whole. If the {100}<011> direction integration intensity is less than 5, the {111}<112> direction integration intensity, which lowers the magnetic flux density, increases, and the overall magnetic flux density decreases. In addition, the production method in which the integrated strength in the {100}<011> orientation exceeds 30 requires a thick hot-rolled sheet, which poses a problem of difficulty in production.
[0109]
The integrated intensity of the {100}<011> orientation can be measured by an X-ray diffraction method or an electron backscatter diffraction (EBSD) method. Since the angle of reflection of X-rays and electron beams from a sample differs for each crystal orientation, the crystal orientation intensity can be obtained from the reflection intensity and the like with reference to a randomly oriented sample. The integrated intensity of the {100}<011> orientation of the preferred non-oriented electrical steel sheet of the present embodiment is 5 to 30 in terms of the X-ray random intensity ratio. At this time, a value obtained by measuring the crystal orientation by EBSD and converting it into an X-ray random intensity ratio may be used.
[0110]
<>
Next, the thickness of the non-oriented electrical steel sheet of this embodiment will be described. The thickness of the non-oriented electrical steel sheet of this embodiment is 0.50 mm or less. If the thickness exceeds 0.50 mm, excellent high-frequency iron loss cannot be obtained. Therefore, the thickness should be 0.50 mm or less.
[0111]
<>
Next, the magnetic properties of the non-oriented electrical steel sheet of this embodiment will be described. When examining the magnetic properties, the value of B50, which is the magnetic flux density of the non-oriented electrical steel sheet of this embodiment, is measured. In the manufactured non-oriented electrical steel sheet, it is impossible to distinguish between one rolling direction and the other. Therefore, in this embodiment, the rolling direction refers to both one and the other. The value of B50 in the rolling direction is B50L, the value of B50 in the direction inclined by 45° from the rolling direction is B50D1, the value of B50 in the direction inclined by 90° from the rolling direction is B50C, and the value of B50 in the direction inclined by 135° from the rolling direction Assuming that the value is B50D2, the anisotropy of magnetic flux density is observed such that B50D1 and B50D2 are the highest and B50L and B50C are the lowest.
[0112]
Here, for example, when considering the omnidirectional (0 ° to 360 °) distribution of the magnetic flux density with the clockwise (or counterclockwise) direction as the positive direction, the rolling direction is 0 ° (one direction) and 180 ° ° (other direction), B50D1 has B50 values ​​of 45° and 225°, and B50D2 has B50 values ​​of 135° and 315°. Similarly, B50L results in B50 values ​​of 0° and 180°, and B50C results in B50 values ​​of 90° and 270°. The 45° and 225° B50 values ​​are in close agreement, and the 135° and 315° B50 values ​​are in close agreement. However, B50D1 and B50D2 may not be exactly the same, since it may not be easy to make the magnetic properties the same in actual manufacturing. Similarly, the 0° and 180° B50 values ​​are closely matched, the 90° and 270° B50 values ​​are closely matched, while the B50L and B50C are closely matched. may not. The non-oriented electrical steel sheet of the present embodiment satisfies the following expressions (2) and (3) using the average values ​​of B50D1 and B50D2 and the average values ​​of B50L and B50C.
(B50D1+B50D2)/2>1.7T (2)
(B50D1+B50D2)/2>(B50L+B50C)/2 (3)
[0113]
In this way, when the magnetic flux density is measured, the average value of B50D1 and B50D2 is 1.7 T or more as in equation (2), and high anisotropy in magnetic flux density is confirmed as in equation (3). .
[0114]
Furthermore, in addition to satisfying the formula (1), it is preferable that the anisotropy of the magnetic flux density is higher than that of the formula (3), as in the following formula (4).
(B50D1+B50D2)/2>1.1×(B50L+B50C)/2 (4)
Furthermore, it is preferable that the anisotropy of the magnetic flux density is higher, as in the following equation (5).
(B50D1+B50D2)/2>1.2×(B50L+B50C)/2 (5)
Furthermore, it is preferable that the average value of B50D1 and B50D2 is 1.8T or more, as in the following formula (6).
(B50D1+B50D2)/2>1.8T (6)
[0115]
In addition, the above 45° is a theoretical value, and since it may not be easy to match it to 45° in actual manufacturing, it includes those that do not strictly match 45°. This is the same for 0°, 90°, 135°, 180°, 225°, 270° and 315°.
[0116]
The magnetic flux density can be measured by cutting out a 55 mm square sample from the direction of 45°, 0°, etc. with respect to the rolling direction and using a single plate magnetic measurement device.
[0117]
<>
Next, an example of a method for manufacturing the non-oriented electrical steel sheet of this embodiment will be described. When manufacturing the non-oriented electrical steel sheet of the present embodiment, for example, hot rolling, cold rolling (first cold rolling), intermediate annealing (first annealing), skin pass rolling (second cold rolling), rolling), finish annealing (third annealing), stress relief annealing (second annealing), and the like are performed.
[0118]
First, the steel materials mentioned above are heated and hot rolled. The steel material is, for example, a slab produced by normal continuous casting. Rough rolling and finish rolling of hot rolling are performed at a temperature in the γ region (Ar1 temperature or higher). That is, hot rolling is performed so that the finish rolling temperature is Ar1 temperature or higher and the coiling temperature is higher than 250° C. and lower than or equal to 600° C. As a result, the subsequent cooling transforms austenite into ferrite, thereby refining the structure. When cold rolling is applied after the fine grains are formed, bulging recrystallization (hereinafter referred to as bulging) is likely to occur, so that {100} crystal grains, which are normally difficult to grow, can be easily grown.
[0119]
Further, when manufacturing the non-oriented electrical steel sheet of the present embodiment, the temperature (finishing temperature) when passing through the final pass of finish rolling is Ar1 temperature or more, and the coiling temperature is more than 250 ° C. and 600 ° C. or less. and The crystal structure is refined by transforming from austenite to ferrite. By refining the crystal structure in this manner, bulging can be easily generated through subsequent cold rolling and intermediate annealing.
[0120]
After that, the hot-rolled steel sheet is coiled without being annealed, pickled, and cold-rolled to the hot-rolled steel sheet. In cold rolling, it is preferable to set the rolling reduction to 80% to 95%. If the rolling reduction is less than 85%, bulging is less likely to occur. If the rolling reduction exceeds 95%, {100} crystal grains tend to grow due to the subsequent bulging, but the hot-rolled steel sheet must be thickened, making it difficult to wind the hot-rolled steel sheet and making the operation difficult. easier. The draft of cold rolling is more preferably 86% or more. Bulging is more likely to occur when the rolling reduction of cold rolling is 86% or more.
[0121]
After cold rolling is completed, intermediate annealing is performed. When manufacturing the non-oriented electrical steel sheet of the present embodiment, intermediate annealing is performed at a temperature that does not transform into austenite. That is, it is preferable to set the temperature of the intermediate annealing to less than the Ac1 temperature. Such intermediate annealing causes bulging and facilitates the growth of {100} crystal grains. Also, the time for the intermediate annealing is preferably 5 seconds to 60 seconds.
[0122]
After intermediate annealing is completed, skin pass rolling is performed next. As described above, when skin-pass rolling and annealing are performed in a state where bulging occurs, {100} crystal grains grow further starting from the portion where bulging occurs. This is because the {100}<011> crystal grains are less likely to be strained by skin pass rolling, and the {111}<112> crystal grains are more likely to be strained. This is because the 011> crystal grains eat the {111}<112> crystal grains with the difference in strain as a driving force. This erosion phenomenon caused by the strain difference as a driving force is called strain-induced grain boundary migration (SIBM). The rolling reduction of skin pass rolling is preferably 5% to 25%. If the rolling reduction is less than 5%, the amount of strain is too small, so SIBM does not occur in subsequent annealing, and the {100}<011> crystal grains do not grow. On the other hand, if the rolling reduction exceeds 25%, the amount of strain becomes too large, and recrystallization nucleation (hereinafter referred to as nucleation) occurs in which new crystal grains are generated from {111}<112> crystal grains. In this Nucleation, most of the grains produced are {111}<112> crystal grains, so the magnetic properties arebecome worse.
[0123]
After skin-pass rolling, finish annealing is performed to release strain and improve workability. The finish annealing is also performed at a temperature that does not transform into austenite, and the finish annealing temperature is lower than the Ac1 temperature. By performing the finish annealing in this manner, the {100}<011> crystal grains eat away the {111}<112> crystal grains, and the magnetic properties can be improved. Also, the time from 600° C. to Ac1 temperature during finish annealing is set within 1200 seconds. If the annealing time is too short, most of the strain introduced by the skin pass remains, and warping occurs when punching a complicated shape. On the other hand, if the annealing time is too long, the crystal grains become too coarse, resulting in large sag during punching and poor punching accuracy.
[0124]
After the finish annealing is completed, the non-oriented electrical steel sheet is processed to form the desired steel member. Then, the steel member made of the non-oriented electrical steel sheet is subjected to strain relief annealing in order to remove strain and the like caused by forming (for example, punching) of the steel member. In the present embodiment, in order to generate SIBM below the Ac1 temperature and make the crystal grain size coarse, the temperature of the stress relief annealing is set to, for example, about 800° C., and the stress relief annealing time is about 2 hours. and Magnetic properties can be improved by stress relief annealing.
[0125]
In the non-oriented electrical steel sheet (steel member) of the present embodiment, among the above-described manufacturing methods, mainly by performing finish rolling at a temperature of Ar1 or higher in the hot rolling process, the high B50 of the formula (1) and the above (2) excellent anisotropy is obtained. Furthermore, by setting the rolling reduction to about 10% in the skin-pass rolling process, more excellent anisotropy of the formula (4) can be obtained.
In addition, in this embodiment, the Ar1 temperature is obtained from the change in thermal expansion of the steel material (steel plate) during cooling at an average cooling rate of 1°C/sec. Further, in this embodiment, the Ac1 temperature is obtained from the change in thermal expansion of the steel material (steel plate) being heated at an average heating rate of 1° C./sec.
[0126]
As described above, a steel member made of the non-oriented electrical steel sheet of this embodiment can be manufactured.
[0127]
Next, the non-oriented electrical steel sheet of this embodiment will be specifically described with reference to examples. The examples shown below are merely examples of non-oriented electrical steel sheets, and the non-oriented electrical steel sheets are not limited to the following examples.
[0128]
<>
By casting molten steel, ingots with the components shown in Tables 1 and 2 below were produced. Here, the left side of the equation represents the value of the left side of the above equation (1). After that, the produced ingot was heated to 1150° C. and hot rolled so as to have a plate thickness of 2.5 mm. After finish rolling, the hot-rolled steel sheet was water-cooled and wound up. The temperature (finishing temperature) at the stage of the final pass of finish rolling at this time was 830° C., and all of them were higher than the Ar1 temperature. In addition, No. 1 where γ-α transformation does not occur. For No. 108, the finishing temperature was 850°C. Further, the winding temperature was set under the conditions shown in Table 1.
[0129]
Next, the hot-rolled steel sheet was pickled to remove scales, and rolled at the rolling reduction after cold rolling shown in Table 1. Then, intermediate annealing was performed at 700° C. for 30 seconds in a non-oxidizing atmosphere. Then, it was rolled at the second cold rolling (skin pass rolling) reduction shown in Table 1.
[0130]
Next, in order to examine the magnetic properties, after the second cold rolling (skin pass rolling), final annealing was performed at 800°C for 30 seconds, and a 55 mm square sample was prepared by shearing, followed by annealing at 800°C for 2 hours. Stress relief annealing was performed and the magnetic flux density B50 was measured. A sample of 55 mm square was taken in two directions of 0° and 45° in the rolling direction. These two types of samples were measured, and the magnetic flux densities B50 at 0°, 45°, 90° and 135° with respect to the rolling direction were defined as B50L, B50D1, B50C and B50D2, respectively.
[0131]
[table 1]

[0132]
[Table 2]

[0133]
The underlines in Tables 1 and 2 indicate conditions outside the scope of the present invention. No. 1, which is an example of the invention. 101 to No. 107, No. 109-No. 111, No. 114 to No. 130 had good magnetic flux density B50 values ​​both in the 45° direction and on the average of the entire circumference. However, no. 116 and No. 127 was out of the appropriate winding temperature, so the magnetic flux density B50 was slightly low. No. 129 and No. No. 130, which has the same composition and coiling temperature, has a low rolling reduction in cold rolling. The magnetic flux density B50 was slightly lower than that of 118. On the other hand, no. In No. 108, the Si concentration was high, the value on the left side of the formula was 0 or less, and the composition did not undergo α-γ transformation, so the magnetic flux density B50 was low in all cases. Comparative example No. 112 had a {100}<011> strength of less than 5 and a low magnetic flux density B50 because the skin pass rolling rate was low. Comparative example No. 113 has a {100}<011> strength of 30 or more, which is out of the scope of the present invention. No. In No. 113, the thickness of the hot-rolled plate was as high as 7 mm, so there was a problem that it was difficult to operate.
[0134]
<>
By casting molten steel, an ingot with the components shown in Table 3 below was produced. After that, the produced ingot was heated to 1150° C. and hot rolled so as to have a plate thickness of 2.5 mm. After finish rolling, the hot-rolled steel sheet was water-cooled and wound up. The finishing temperature at the stage of the final pass of finish rolling at this time was 830° C., which was higher than the Ar1 temperature in all cases.
[0135]
Next, the hot-rolled steel sheet was pickled to remove scales, and cold-rolled until the sheet thickness reached 0.385 mm. Then, intermediate annealing was performed in a non-oxidizing atmosphere, and the temperature of the intermediate annealing was controlled so that the recrystallization rate was 85%. Then, the second cold rolling (skin pass rolling) was performed until the sheet thickness reached 0.35 mm.
[0136]
Next, in order to examine the magnetic properties, after the second cold rolling (skin pass rolling), final annealing was performed at 800°C for 30 seconds, and a 55 mm square sample was prepared by shearing, followed by annealing at 800°C for 2 hours. After strain relief annealing, magnetic flux density B50 and core loss W10/400 were measured. The magnetic flux density B50 was measured in the same procedure as in the first example. On the other hand, the iron loss W10/400 was measured as the energy loss (W/kg) generated in the sample when an alternating magnetic field of 400 Hz was applied so that the maximum magnetic flux density was 1.0T. Iron loss was the average value of the results of measurements at 0°, 45°, 90° and 135° with respect to the rolling direction.
[0137]
[Table 3]

[0138]
[Table 4]

[0139]
　No. 201 to No. All No. 214 are invention examples, and all of them had good magnetic properties. In particular, No. 202-No. 204 is No. 201, No. 205-No. The magnetic flux density B50 is higher than that of No. 214. 205-No. 214 is No. 201 to No. Iron loss W10/400 was lower than that of 204.
[0140]
Although the present invention has been described along with various embodiments, the present invention is not limited to these embodiments, and modifications and the like are possible within the scope of the present invention.
In the above description, the case where the operating condition is the torque ratio has been explained, but the operating condition is not limited to this case, and may be the rotation speed ratio or the torque ratio for each rotation speed ratio.
Industrial applicability
[0141]
According to the present invention, it is possible to reduce variations in magnetic flux density and suppress iron loss. Therefore, industrial applicability is high.
Code explanation
[0142]
100: Rotating electric machine
　110: rotor
　120: Stator
　121a-121p: Teeth
122: York
　130: Rotation axis
400: Motor
410: rotor
411: Permanent magnet
421: Stator core
422: Coil
　501a to 501m: Stator
　1600: Motor
　1610: rotor
　1621: Stator core
　1622: Coil
　1701a-1701p: Stator
　2700: Stator core design device
2701: Operation data acquisition unit
　2702: Operating condition/operating ratio identification unit
2703: Average magnetic flux density acquisition unit
2704: Evaluation magnetic flux density calculation unit
2705: Average magnetic field strength calculation unit
2706: Teeth magnetic flux density acquisition unit
　2707: Teeth width determination part
　2708: Stator core design department

The scope of the claims

[Claim 1]
A stator core having a plurality of laminated electromagnetic steel sheets,
A stator core characterized in that, among the plurality of teeth of the stator core, the width of the teeth along the direction with excellent magnetic properties is narrower than the width of the teeth along the directions with poor magnetic properties.
[Claim 2]
In the teeth of the stator core,
The stator core according to claim 1, wherein the product of the width of the teeth of the stator core and the magnetic flux density of the teeth when excited with a predetermined magnetic field intensity is substantially constant for each tooth.
[Claim 3]
The stator core is constructed by laminating rolled electromagnetic steel sheets,
The electromagnetic steel sheet is
in % by mass,
C: 0.0100% or less,
Si: 1.50% to 4.00%,
sol. Al: 0.0001% to 1.0%,
S: 0.0100% or less,
N: 0.0100% or less,
One or more selected from the group consisting of Mn, Ni, Co, Pt, Pb, Cu, and Au: 2.50% to 5.00% in total,
Sn: 0.000% to 0.400%,
Sb: 0.000% to 0.400%,
P: 0.000% to 0.400%, and
One or more selected from the group consisting of Mg, Ca, Sr, Ba, Ce, La, Nd, Pr, Zn, and Cd: 0.0000% to 0.0100% in total,
Mn content (mass%) [Mn], Ni content (mass%) [Ni], Co content (mass%) [Co], Pt content (mass%) [Pt], Pb content [Pb] for Cu content (% by mass), [Cu] for Cu content (% by mass), [Au] for Au content (% by mass), [Si] for Si content (% by mass), sol. The Al content (% by mass) is measured as [sol. Al], the following formula (1) is satisfied,
　The balance has a chemical composition consisting of Fe and impurities,
The value of B50 in the rolling direction is B50L, the value of B50 in the direction inclined by 45° from the rolling direction is B50D1, the value of B50 in the direction inclined by 90° from the rolling direction is B50C, and the value of B50 in the direction inclined by 135° from the rolling direction When the value is B50D2, the following formulas (2) and (3) are satisfied, the X-ray random intensity ratio of {100} <011> is 5 or more and less than 30, and the plate thickness is 0.50 mm or less can be,
The direction with excellent magnetic properties is the direction at an angle of 45° from the rolling direction, and the direction with poor magnetic properties is the direction at angles of 0° and 90° from the rolling direction,
The width of the teeth along the direction at an angle of 45° from the rolling direction, the width of the teeth along the direction at an angle of 0° from the rolling direction, and the direction at an angle of 90° from the rolling direction 3. A stator core according to claim 1 or 2, wherein the width is narrower than any of the widths of the teeth along.
([Mn] + [Ni] + [Co] + [Pt] + [Pb] + [Cu] + [Au]) - ([Si] + [sol. Al]) > 0% (1)
(B50D1+B50D2)/2>1.7T (2)
(B50D1+B50D2)/2>(B50L+B50C)/2 (3)
[Claim 4]
The stator core according to claim 3, which satisfies the following formula (4).
(B50D1+B50D2)/2>1.1×(B50L+B50C)/2 (4)
[Claim 5]
The stator core according to claim 3, which satisfies the following formula (5).
(B50D1+B50D2)/2>1.2×(B50L+B50C)/2 (5)
[Claim 6]
The stator core according to claim 3, which satisfies the following formula (6).
(B50D1+B50D2)/2>1.8T (6)
[Claim 7]
Any one of claims 1 to 6A rotating electric machine comprising the stator core according to 1.
[Claim 8]
A design method for a stator core having laminated electromagnetic steel sheets,
A tooth magnetic flux density acquisition step for acquiring information on the magnetic flux density of the teeth when excited with a predetermined magnetic field strength,
a determination step of determining the width of the teeth of the stator core so that the product of the width of the teeth of the stator core and the magnetic flux density of the teeth obtained by the step of obtaining the magnetic flux density of the teeth is substantially constant for each tooth; A method for designing a stator core, comprising:
[Claim 9]
an operation data acquisition step of acquiring operation data of the rotating electric machine when operating the rotating electric machine including the stator core;
a specifying step of specifying an operating condition with the highest operating time ratio among a plurality of operating conditions based on the operating data acquired by the operating data acquiring step;
an average magnetic flux density acquisition step of acquiring information on the average magnetic flux density of the teeth corresponding to the operating condition with the highest ratio specified in the specifying step;
and an average magnetic field intensity calculation step of calculating the average magnetic field intensity of the teeth from the information of the average magnetic flux density of the teeth acquired by the average magnetic flux density acquisition step,
　In the tooth magnetic flux density acquisition process,
The stator core design method according to claim 8, wherein information on the magnetic flux density of the teeth when excited with the average magnetic field strength calculated in the average magnetic field strength calculation step is obtained.
[Claim 10]
an operation data acquisition step of acquiring operation data of the rotating electric machine when operating the rotating electric machine including the stator core;
a specifying step of specifying the operating time ratio for each of a plurality of operating conditions based on the operating data acquired by the operating data acquiring step;
an average magnetic flux density acquisition step of acquiring information on the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions;
Average magnetic field strength for calculating the average magnetic field strength of the teeth for each of the plurality of operating conditions from the information of the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions acquired by the average magnetic flux density acquiring step a calculating step;
　In the tooth magnetic flux density acquisition process,
Acquire information on the magnetic flux density of the teeth for each of the plurality of operating conditions when the teeth are excited with the average magnetic field strength for each of the plurality of operating conditions calculated by the average magnetic field strength calculation step,
　In the decision process,
calculating the width of the teeth for each of the plurality of operating conditions so that the product of the width of the teeth of the stator core and the magnetic flux density of the teeth obtained in the tooth magnetic flux density obtaining step is substantially constant for each tooth; 9. The tooth width after weighting is determined by weighting the calculated tooth width for each of the plurality of operating conditions based on the ratio of the operating time specified in the specifying step. How to design the described stator core.
[Claim 11]
an operation data acquisition step of acquiring operation data of the rotating electric machine when operating the rotating electric machine including the stator core;
a specifying step of specifying the operating time ratio for each of a plurality of operating conditions based on the operating data acquired by the operating data acquiring step;
an average magnetic flux density acquisition step of acquiring information on the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions;
Evaluation magnetic flux density of the teeth weighted based on the ratio of the operating time specified by the specifying step from the information of the average magnetic flux density of the teeth corresponding to each of the plurality of operating conditions acquired by the average magnetic flux density acquiring step. an evaluation magnetic flux density calculation step of calculating
and an average magnetic field strength calculation step of calculating the average magnetic field strength of the teeth from the evaluation magnetic flux density of the teeth calculated by the evaluation magnetic flux density calculation step,
　In the tooth magnetic flux density acquisition process,
The method for designing a stator core according to claim 8, wherein information on the magnetic flux density of the teeth when excited with the average magnetic field strength of the teeth calculated in the average magnetic field strength calculation step is obtained.
[Claim 12]
　In the operation data acquisition process,
The stator core design method according to any one of claims 9 to 11, wherein at least one of plan data and performance data of the rotary electric machine including the stator core is acquired.