Laminated core and rotating electric machine using same

Abstract

To provide a laminated iron core capable of restraining excessive increase of iron loss while exhibiting saturated magnetic flux density higher than a mere electromagnetic iron plate, and enabling lower cost than permendur, and a rotary electric machine using the laminated iron core.SOLUTION: A laminated iron core according to the present invention is formed by laminating a plural types of soft magnetic iron plates. The plural types of soft magnetic iron plates include a first soft magnetic iron plate and a second magnetic iron plate. The first soft magnetic iron plate and the second magnetic iron plate are alternately laminated. The first soft magnetic iron plate has a higher nitrogen content and a higher saturated magnetic flux density than the second magnetic iron plate. The second magnetic iron plate has a coercive force lower than the first soft magnetic iron plate.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to iron core technology, and more particularly to a laminated iron core having a saturation magnetic flux density higher than that of electromagnetic pure iron, and a rotating electric machine using the same. [Background technology]

[0002] Laminated cores made by laminating multiple electromagnetic pure iron sheets or electromagnetic steel sheets (e.g., 0.01 to 1 mm thick) are widely used as cores for rotating electrical machines and transformers. For iron cores, it is important that the conversion efficiency between electrical energy and magnetic energy is high, so high magnetic flux density and low iron loss are important.

[0003] On the other hand, in mechanical devices that use iron cores, reducing the cost of iron cores is naturally one of the important issues, and technological development has been actively carried out for a long time to manufacture iron cores cheaply and stably while satisfying the required characteristics.

[0004] For example, Patent Document 1 (JP 2018-174650 A) describes a motor core formed by laminating a plurality of magnetic materials, in which a first magnetic material among the plurality of magnetic materials has a magnetic flux density B 50 The second magnetic material has a magnetic permeability at 1.0 T and 400 Hz that is 50% or more higher than that of the first magnetic material, and an iron loss W 10 / 400 The document discloses an iron core having a volume fraction of the second magnetic material of 10 to 90%, lower than that of the first magnetic material. The document also discloses that the second magnetic material is preferably an electromagnetic steel sheet containing 6.0 to 7.0% Si.

[0005] According to Patent Document 1, by using a material in which the Si concentration in the surface layer is controlled to be high, it is possible to effectively reduce losses at high frequencies. In addition, by using an electromagnetic steel sheet in which the Si concentration is high only in the surface layer, it is possible to suppress the decrease in saturation magnetic flux density, and ensure operating characteristics under high torque drive conditions. In other words, it is said that by combining a first magnetic material, which is a high magnetic flux density material, with a second magnetic material, which is a high magnetic permeability and low iron loss material, it is possible to obtain an iron core that enables high efficiency and high torque drive.

[0006] Patent Document 2 (JP 2020-132894 A) discloses a plate- or foil-shaped soft magnetic material having a high saturation magnetic flux density, which contains iron, carbon, and nitrogen, and includes martensite containing carbon and nitrogen and γ-Fe, in which a phase containing nitrogen is formed in the γ-Fe.

[0007] According to Patent Document 2, a soft magnetic material that has a saturation magnetic flux density exceeding that of pure iron and has thermal stability can be manufactured at low cost and used to improve the characteristics of magnetic circuits of electric motors, etc., thereby enabling miniaturization of electric motors, etc., and increasing torque, etc. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2018-174650 A [Patent Document 2] JP 2020-132894 A Summary of the Invention [Problem to be solved by the invention]

[0009] In rotating electrical machines, it is important to increase the saturation magnetic flux density Bs of the iron core to achieve high output and high torque, and it is also important to suppress the loss in the iron core (iron loss Pi) to achieve high efficiency. Iron loss Pi is the sum of hysteresis loss and eddy current loss, and a small coercive force Hc is desirable to reduce hysteresis loss, while high electrical resistance and thin plates are effective in reducing eddy current loss.

[0010] The magnetic properties of commercially available electromagnetic pure iron plates are said to be Bs ≒ 2.1 T. An iron core using an electromagnetic pure iron plate has the advantages of high Bs and low material cost, but has the disadvantage that Pi is easily increased due to a relatively high Hc. The iron core of Patent Document 1 has the advantage of having a smaller Pi than an electromagnetic pure iron plate core, but has the disadvantage that the Bs of the entire iron core does not exceed that of an electromagnetic pure iron core because the Bs of the electromagnetic steel plate used is smaller than that of the electromagnetic pure iron plate. In addition, the soft magnetic material of Patent Document 2 has the advantage of having a higher Bs than an electromagnetic pure iron plate, but is thought to have the disadvantage of having a higher Hc than an electromagnetic pure iron plate.

[0011] Known iron-based materials that have a higher Bs than electromagnetic pure iron sheets include Fe-Co-based materials and Fe-N-based martensitic materials.

[0012] Among the Fe-Co based materials, permendur (49Fe-49Co-2V mass% = 50Fe-48Co-2V atomic%) is the material that shows the highest Bs among the currently commercially available soft magnetic materials. However, the material cost of Co, although it varies depending on the market conditions, is 100 to 200 times higher than the material cost of Fe, so permendur has the disadvantage of being high material cost. Permendur also has some difficulty in processability, and it also has the disadvantage that the processing cost tends to be high. If the Co content is reduced, the material cost can be reduced accordingly and processability can be improved, but unfortunately, the Bs, which is the greatest feature, also decreases.

[0013] On the other hand, Fe-N martensitic materials (e.g., Fe 8 N phase (α' phase), Fe 16 N 2The α″ phase (α′′ phase) is an attractive material with a material cost far lower than permendur and a high Bs comparable to that of permendur. However, it has a weakness in that Hc and Pi are easily increased due to an increase in crystal lattice distortion caused by the intrusion of N atoms and a difference in distortion between crystal lattices due to local concentration differences of N atoms.

[0014] In recent years, there has been a strong demand for high torque / high output designs in rotating electrical machines and transformers, and there is a strong demand for improved Bs of the core. In other words, improving the Bs of the core is given priority, and if the degree of improvement in Bs is large, a certain degree of increase in Pi tends to be tolerated.

[0015] Therefore, an object of the present invention is to provide a laminated core that exhibits a higher Bs than electromagnetic pure iron plate while suppressing an excessive increase in Pi, and that can be made less expensive than permendur, and a rotating electric machine that uses said laminated core. [Means for solving the problem]

[0016] (I) One aspect of the present invention is a laminated core in which multiple types of soft magnetic iron plates are laminated, The plurality of types of soft magnetic iron plates include a first soft magnetic iron plate and a second soft magnetic iron plate, The first soft magnetic iron plates and the second soft magnetic iron plates are alternately laminated, the first soft magnetic iron plate has a higher nitrogen content and a higher saturation magnetic flux density than the second soft magnetic iron plate; The second soft magnetic iron plate has a lower coercive force than the first soft magnetic iron plate.

[0017] In the present invention, the soft magnetic iron plate is defined to include not only a pure iron plate but also a soft magnetic iron alloy plate.

[0018] The present invention allows the following improvements and modifications to be made to the laminated core (I) according to the present invention. (i) The first soft magnetic iron plate is an Fe-Co-N based iron plate having a chemical composition containing 1 atomic % or more and 25 atomic % or less of cobalt (Co), 2 atomic % or more and 10 atomic % or less of nitrogen (N), 0 atomic % or more and 1 atomic % or less of vanadium (V), with the remainder being iron (Fe) and impurities. (ii) the ratio of the saturation magnetic flux density of the second soft magnetic iron plate to the saturation magnetic flux density of the first soft magnetic iron plate is 0.8 or more and less than 1. (iii) The second soft magnetic iron plate has a saturation magnetic flux density of 2.0 T or more. (iv) The thickness of the first soft magnetic iron plate and the second soft magnetic iron plate is 0.01 mm or more and 1 mm or less, and the thickness of the first soft magnetic iron plate is 1 time or more and 5 times or less the thickness of the second soft magnetic iron plate. (v) The soft magnetic iron plate of the outermost layer has a magnetostriction constant equal to or less than the magnetostriction constants of the other soft magnetic iron plates. (vi) The soft magnetic iron plate of the outermost layer is a third soft magnetic iron plate different from the first soft magnetic iron plate and the second soft magnetic iron plate. (vii) Between adjacent soft magnetic iron plates, 1×10 6 An electrical insulating layer with an electrical resistivity of Ω·cm or more is interposed.

[0019] (II) Another aspect of the present invention is a rotating electric machine having a laminated core, The present invention also provides a rotating electric machine, wherein the laminated core is the laminated core according to the present invention. Effect of the Invention

[0020] According to the present invention, it is possible to provide a laminated core that exhibits a higher Bs than electromagnetic pure iron plate while suppressing an excessive increase in Pi, and that can be made at a lower cost than permendur, and a rotating electric machine that uses the laminated core. [Brief description of the drawings]

[0021] [Figure 1] 1 is a schematic cross-sectional view showing an example of a laminated core according to the present invention. [Diagram 2]FIG. 4 is a schematic cross-sectional view showing another example of a laminated core according to the present invention. [Figure 3A] FIG. 2 is a schematic perspective view showing an example of a stator of a rotating electric machine. [Figure 3B] FIG. 2 is an enlarged schematic cross-sectional view of a slot region of the stator. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, the embodiments of the present invention will be described in more detail with reference to the drawings. However, the present invention is not limited to the embodiments described herein, and can be appropriately combined with known techniques or improved based on known techniques without departing from the technical concept of the invention.

[0023] [Laminated core of the present invention] Fig. 1 is a schematic cross-sectional view showing an example of a laminated core according to the present invention. As shown in Fig. 1, a laminated core 10 according to the present invention is formed by alternately laminating first soft magnetic iron plates 1 and second soft magnetic iron plates 2. From the viewpoint of reducing eddy current loss, it is preferable that adjacent soft magnetic iron plates are electrically insulated via an electrical insulating layer 4 (for example, an electrical insulating adhesive layer).

[0024] Since one of the purposes of the laminated core 10 of the present invention is to exhibit a Bs superior to that of an electromagnetic pure iron plate, at least one of the first soft magnetic iron plate 1 and the second soft magnetic iron plate 2 must have a Bs higher than that of an electromagnetic pure iron plate. Numerous experiments by the inventors have revealed that if the Bs is improved by 0.03 T or more compared to the soft magnetic material, it can be said to be a clear characteristic improvement / significant difference. For this reason, it is preferable that at least one of the first soft magnetic iron plate 1 and the second soft magnetic iron plate 2 has a magnetic characteristic of "Bs≧2.17 T".

[0025] Another object of the laminated core 10 of the present invention is to reduce the cost compared to Permendur. Therefore, at least one of the first soft magnetic iron plate 1 and the second soft magnetic iron plate 2 contains N components to compensate for the decrease in Bs while reducing the Co content compared to Permendur to reduce the material cost.

[0026] However, since N-containing iron plates tend to have an increased Hc as mentioned above, in order to prevent an excessive increase in Pi of the entire laminated iron core 10 (so that the increase in Pi is within the allowable range for designing a rotating electric machine), the N content of at least one of the first soft magnetic iron plate 1 and the second soft magnetic iron plate 2 is kept low to suppress the increase in Hc.

[0027] When multiple types of soft magnetic iron plates are laminated, magnetostatic coupling occurs between adjacent soft magnetic iron plates as a magnetic effect. This magnetostatic coupling acts between the soft magnetic iron plates to minimize magnetic energy, so when the magnetization direction of one soft magnetic iron plate changes, the magnetization direction of the other soft magnetic iron plate also changes accordingly. By keeping the Hc of at least one of the first soft magnetic iron plate 1 and the second soft magnetic iron plate 2 low, the Hc of the laminated core 10 as a whole can be suppressed.

[0028] More specifically, the first soft magnetic iron plate 1 is preferably an Fe-Co-N-based iron plate having a chemical composition including 1 atomic % to 25 atomic % Co, 2 atomic % to 10 atomic % N, 0 atomic % to 1 atomic % V, and the remainder being Fe and impurities. From the viewpoint of the balance between Bs and material cost, the Co content is more preferably 3 atomic % to 23 atomic % and even more preferably 5 atomic % to 20 atomic %. From the viewpoint of the balance between Bs and Hc, the N content is more preferably 3 atomic % to 8 atomic % and even more preferably 4 atomic % to 7 atomic %. V is a component that contributes to improving the workability of the iron plate, but is not an essential component (it may or may not be contained).

[0029] From the viewpoint of Hc, the second soft magnetic iron plate 2 preferably has a lower N content than the first soft magnetic iron plate 1. Furthermore, from the viewpoint of the Bs of the entire laminated iron core 10, the Bs of the second soft magnetic iron plate 2 is preferably 0.8 or more and less than 1 of the Bs of the first soft magnetic iron plate 1, more preferably 2.0 T or more, and even more preferably 2.1 T or more. More specifically, the second soft magnetic iron plate 2 is preferably an electromagnetic pure iron plate, or an iron plate having a higher Co content than the first soft magnetic iron plate 1 and containing no N components.

[0030] There is no particular limitation on the thickness of the first soft magnetic iron plate 1 and the second soft magnetic iron plate 2, and it can be appropriately selected within the range of 0.01 mm or more and 1 mm or less. From the viewpoint of controllability of the N content, the thickness of the first soft magnetic iron plate 1 is preferably 0.03 mm or more and 0.5 mm or less, and more preferably 0.05 mm or more and 0.3 mm or less. In addition, from the viewpoint of Bs and Hc of the entire laminated iron core 10, the ratio of the thickness of the first soft magnetic iron plate 1 to the second soft magnetic iron plate 2 is preferably 1 time or more and 5 times or less, and more preferably 1 time or more and 4 times or less, of the thickness of the second soft magnetic iron plate 2.

[0031] Regarding the electrical insulation layer 4, from the viewpoint of ensuring electrical insulation, 6 It is preferable that the electrical insulating layer 4 has an electrical resistivity of Ω·cm or more. There is no particular limitation on the thickness of the electrical insulating layer 4, but the thickness of the electrical insulating layer 4 is preferably 1 μm or more and 10 μm or less, and more preferably 2 μm or more and 5 μm or less, so that the space factor of the soft magnetic iron plates in the laminated iron core is 90 volume % or more. The space factor of the soft magnetic iron plates in the laminated iron core is more preferably 95 volume % or more, and even more preferably 97 volume % or more.

[0032] Fig. 2 is a schematic cross-sectional view showing another example of a laminated core according to the present invention. As shown in Fig. 2, a laminated core 20 has a third soft magnetic iron plate 3 disposed on the outermost layer of a first soft magnetic iron plate 1 and a second soft magnetic iron plate 2 that are alternately laminated. It is preferable to use, as the third soft magnetic iron plate 3, one having the smallest magnetostriction constant among the soft magnetic iron plates to be laminated.

[0033] More specifically, when there are only two types of soft magnetic iron plates to be laminated (the first soft magnetic iron plate 1 and the second soft magnetic iron plate 2), the one of the first soft magnetic iron plate 1 and the second soft magnetic iron plate 2 with the smaller magnetostriction constant is arranged in the outermost layer. In other words, the one with the smaller magnetostriction constant also serves as the third soft magnetic iron plate 3. When there are three or more types of soft magnetic iron plates to be laminated, the soft magnetic iron plate with the smallest magnetostriction constant is arranged in the outermost layer as the third soft magnetic iron plate 3. However, from the viewpoint of the Bs of the entire laminated iron core 20, the Bs of the third soft magnetic iron plate 3 is also preferably 0.8 or more and less than 1 of the Bs of the first soft magnetic iron plate 1, more preferably 2.0 T or more, and even more preferably 2.1 T or more.

[0034] By placing soft magnetic iron plates, which have the smallest magnetostriction constant, in the outermost layers of the laminated core, it is possible to minimize the increase in Pi of the laminated core even in environments where external stress is applied to the laminated core (for example, the assembly process of the laminated core or the process of incorporating it into rotating electrical machine components).

[0035] [Rotary electric machine using the laminated core of the present invention] Fig. 3A is a schematic perspective view showing an example of a stator of a rotating electric machine, and Fig. 3B is an enlarged schematic cross-sectional view of a slot region of the stator. Note that the cross-sectional view means a cross section perpendicular to the rotation axis direction (a cross section whose normal line is parallel to the axial direction). In the rotating electric machine, a rotor (not shown) is disposed radially inside the stator of Figs. 3A and 3B.

[0036] 3A and 3B, the stator 30 has stator coils 31 wound in a plurality of stator slots 21 formed on the inner periphery of the laminated core 20. The stator slots 21 are spaces that are arranged and formed at a predetermined circumferential pitch around the circumferential direction of the laminated core 20 and penetrate the laminated core 20 in the axial direction, and slits 22 are formed in the innermost periphery and extend in the axial direction. The areas partitioning adjacent stator slots 21 are referred to as teeth 23 of the laminated core 20, and the parts of the inner periphery tip areas of the teeth 23 that define the slits 22 are referred to as tooth claw portions 24.

[0037] The stator coil 31 is usually composed of a plurality of segment conductors 32. For example, in Fig. 3A and Fig. 3B, the stator coil 31 is composed of three segment conductors 32 corresponding to the U-phase, V-phase, and W-phase of a three-phase AC. In order to prevent partial discharge between the segment conductors 32 and the laminated core 20 and partial discharge between the phases (U-phase, V-phase, W-phase), the outer periphery of each segment conductor 32 is usually covered with an electrical insulating material 33 (e.g., insulating paper, enamel coating).

[0038] The rotating electric machine according to the present invention is a rotating electric machine that uses the laminated core 21 according to the present invention. As described above, the laminated core 21 according to the present invention has a higher Bs than conventional laminated cores made of pure electromagnetic iron sheets or electromagnetic steel sheets, which leads to higher torque and smaller size of the rotating electric machine. In addition, the laminated core 21 according to the present invention can be manufactured at a lower cost than a laminated core made of permendur sheets, which makes it possible to suppress excessive cost increases of the rotating electric machine. EXAMPLES

[0039] The present invention will be explained in more detail below with reference to various experiments, however, the present invention is not limited to the configurations and structures described in these experiments.

[0040] [Experiment 1] (Prepare soft magnetic iron plate) Commercially available pure metal raw materials (Fe, Co, each with a purity of 99.9%) were mixed and an alloy ingot was prepared by arc melting on a water-cooled copper hearth (Dai-A Vacuum Co., Ltd., automatic arc melting furnace, reduced pressure Ar atmosphere). The alloy ingot was remelted six times while being inverted to homogenize it. The obtained alloy ingot was pressed and rolled to prepare Fe-5 at% Co plates (thickness = 0.1 mm, hereafter referred to as Fe-5Co plates), Fe-10 at% Co plates (thickness = 0.1 mm, hereafter referred to as Fe-10Co plates), Fe-20 at% Co plates (thickness = 0.1 mm, hereafter referred to as Fe-20Co plates), and Fe-50 at% Co plates (thickness = 0.1 mm, 0.05 mm, 0.025 mm, hereafter referred to as Fe-50Co plates).

[0041] In addition, commercially available electromagnetic pure iron plate (thickness = 0.1 mm, hereafter referred to as Fe plate), electromagnetic steel plate (thickness = 0.1 mm, hereafter referred to as Fe-3Si plate), amorphous iron plate 1 (thickness = 0.025 mm, hereafter referred to as Fe-12Si-10B plate), and amorphous iron plate 2 (thickness = 0.02 mm, hereafter referred to as Fe-1Cu-3Nb-13Si-9B plate) were separately prepared.

[0042] The Fe, Fe-5Co, Fe-10Co, and Fe-20Co sheets prepared above were subjected to nitrogen immersion heat treatment to introduce N components. In the nitrogen immersion heat treatment, NH 3 Gas (1 x 10 5 The temperature was raised to 800°C, which is the stable temperature of the austenite phase (γ phase), and then NH 3 Gas and N 2 Gas (1 x 10 5 The introduction and diffusion of N components were controlled by alternating between 0.25 and 1.0 Pa to achieve a N concentration of 5 atomic %. The specimens were then oil quenched (60°C) to cause martensitic transformation, and then ultra-subzero treatment in liquid nitrogen was performed to cause the residual γ phase to also transform into martensitic. In this way, Fe-5 atomic % N plates (hereafter referred to as Fe-5N plates), Fe-5 atomic % Co-5 atomic % N plates (hereafter referred to as Fe-5Co-5N plates), Fe-10 atomic % Co-5 atomic % N plates (hereafter referred to as Fe-10Co-5N plates), and Fe-20 atomic % Co-5 atomic % N plates (hereafter referred to as Fe-20Co-5N plates) were fabricated.

[0043] [Experiment 2] (Investigation of magnetic properties of soft magnetic iron plate) We investigated the magnetic properties (Bs, Hc, Pi, magnetostriction constant) of the various soft magnetic iron plates prepared in Experiment 1. The size of the measurement sample was 20 mm wide × 60 mm long.

[0044] The magnetization (unit: emu) of the sample was measured using a vibrating sample magnetometer (Riken Denshi Co., Ltd., BHV-525H) under conditions of a magnetic field of 1.6 MA / m and a temperature of 20°C, and Bs (unit: T) and coercive force Hc (unit: A / m) were calculated from the sample volume and mass. The Pi of the sample was measured using a BH loop analyzer (IFG Co., Ltd., IF-BH550) and the H coil method (compliant with JIS C 2556:2015) using a vertical yoke single sheet tester under conditions of a magnetic flux density of 1.0 T, 400 Hz, and a temperature of 20°C. -1.0 / 400 The magnetostriction constant (unit: W / kg) was measured. In addition, the displacement of the sample when an AC magnetic field of 10 kA / m was applied in the longitudinal direction of the sample was measured using an optical heterodyne laser displacement meter (TLVM type, manufactured by Toei Industry Co., Ltd.), and the magnetostriction constant was calculated from the relationship between the applied magnetic field and the displacement. The results are shown in Table 1.

[0045] [Table 1]

[0046] As shown in Table 1, it is confirmed that the Fe-Co based plate has a higher Bs and a lower Hc and Pi than the Fe plate. The Fe-N based plate and the Fe-Co-N based plate have a higher Bs than the Fe plate, but also have a higher Hc and Pi. The Fe-3Si plate, the Fe-12Si-10B plate, and the Fe-1Cu-3Nb-13Si-9B plate have a lower Hc and Pi than the Fe plate, but also have a lower Bs.

[0047] [Experiment 3] (Making laminated cores) A laminated core was made using the various soft magnetic iron plates prepared in Experiment 1. In making the laminated core, the soft magnetic iron plates with the smaller magnetostriction constant were laminated so that they were the outermost layers, and epoxy resin (electrical resistivity = 1 × 10) was used as an electrically insulating adhesive layer between the soft magnetic iron plates. 7A compressive stress of 5 to 10 MPa was applied in the lamination direction until the adhesive layer hardened using a tensile test piece (stress density = 1.0 Ω·cm, average thickness = 5 μm). After laminating and bonding the soft magnetic iron plates, they were held at 150°C for 24 hours to remove distortion caused by pressure bonding. The space factor of the soft magnetic iron plates in the laminated core was approximately 95 volume %. The specifications of the laminated core produced are shown in Table 2 below.

[0048] [Experiment 4] (Investigation of magnetic properties of laminated cores) Magnetic properties of various laminated cores produced in experiment 3 (Bs, Hc, Pi -1.0 / 400 ) was investigated in a similar manner to Experiment 2.

[0049] As mentioned above, one of the purposes of the laminated core of the present invention is to show a superior Bs to electromagnetic pure iron sheets, and an increase of 0.03 T or more is required to say that Bs is a clear improvement in characteristics / a significant difference. Therefore, regarding Bs, a value of 2.17 T or more is judged as "good," and a value of less than 2.17 T is judged as "poor." In addition, Pi -1.0 / 400 For Pi, the design tolerance is set at less than 40 W / kg when the Bs is 2.17 T or more. -1.0 / 400 A value of less than 40 W / kg was judged to be "good," and a value of 40 W / kg or more was judged to be "poor." The results of the investigation into the magnetic properties of the laminated core are shown in Table 2.

[0050] [Table 2]

[0051] As shown in Table 2, samples 1 to 7 have Bs of 2.17 T or more and Pi -1.0 / 400is less than 40 W / kg, and both are judged to be "good". With regard to material cost, the second soft magnetic iron sheets of Samples 2 to 6 are equivalent to Permendur, but the first soft magnetic iron sheets of Samples 1 to 7, the second soft magnetic iron sheet of Sample 1, and the second soft magnetic iron sheet of Sample 7 are cheaper than Permendur because of their low Co content. As a result, it can be said that the laminated core as a whole is less expensive than Permendur. In other words, it can be said that Samples 1 to 7 achieve all of the objects of the present invention.

[0052] In contrast, samples 8 and 9 showed Bs and Pi -1.0 / 400 and did not meet the required level, and sample 10 was -1.0 / 400 does not satisfy the required level. In other words, Samples 8 to 10 are judged to be “defective”.

[0053] Considering the results of Table 2. For example, a comparison between Sample 7 and Sample 8 shows that the Bs of the second soft magnetic iron plate is preferably 0.8 or more times the Bs of the first soft magnetic iron plate, and more preferably 2.0 T or more. A comparison between Samples 4 to 6 shows that the thickness of the first soft magnetic iron plate is preferably 1 to 5 times the thickness of the second soft magnetic iron plate.

[0054] [Experiment 5] (Production of modified laminated cores and investigation of their magnetic properties) The Fe-20Co-5N plate (thickness = 0.1 mm), Fe-50Co plate (thickness = 0.1 mm), and Fe plate (thickness = 0.1 mm) prepared in Experiment 1 were used as the first soft magnetic iron plate, the second soft magnetic iron plate, and the third soft magnetic iron plate, respectively, and the laminated core shown in Figure 2 was fabricated in the same manner as in Experiment 3.

[0055] The magnetic properties of the obtained laminated core were investigated in the same manner as in Experiment 2. The results were Bs = 2.30 T, Hc = 55 A / m, and Pi -1.0 / 400 It was confirmed that magnetic properties of 0.05 W / kg were obtained, and that, together with the reduction in material costs, all of the objects of the present invention were achieved.

[0056] The above-mentioned embodiments and experiments are described to aid in understanding of the present invention, and the present invention is not limited to the specific configurations described. For example, it is possible to replace a part of the configuration of the embodiments with a configuration according to the technical common sense of a person skilled in the art, and it is also possible to add a configuration according to the technical common sense of a person skilled in the art to the configuration of the embodiments. In other words, it is possible to delete, replace, or add a part of the configuration of the embodiments or experiments in this specification without departing from the technical idea of ​​the invention. [Explanation of symbols]

[0057] 10,20…Laminated core, 1...first soft magnetic iron plate, 2...second soft magnetic iron plate, 3...third soft magnetic iron plate, 4...electrical insulation layer 21... stator slot, 22... slit, 23... teeth, 24... teeth claw portion, 30... stator, 31... stator coil, 32... segment conductor, 33... electrical insulation material.

Claims

1. A laminated core in which multiple types of soft magnetic iron plates are laminated, The plurality of types of soft magnetic iron plates include a first soft magnetic iron plate and a second soft magnetic iron plate, The first soft magnetic iron plates and the second soft magnetic iron plates are alternately laminated, the first soft magnetic iron plate has a higher nitrogen content and a higher saturation magnetic flux density than the second soft magnetic iron plate; A laminated core, wherein the second soft magnetic iron plate has a lower coercive force than the first soft magnetic iron plate.

2. 2. The laminated core according to claim 1, The first soft magnetic iron plate is an iron-cobalt-nitrogen based iron plate having a chemical composition containing 1 atomic % or more and 25 atomic % or less of cobalt, 2 atomic % or more and 10 atomic % or less of nitrogen, 0 atomic % or more and 1 atomic % or less of vanadium, with the remainder being iron and impurities.

3. The laminated core according to claim 1 or 2, A laminated core, characterized in that the ratio of the saturation magnetic flux density of the second soft magnetic iron plate to the saturation magnetic flux density of the first soft magnetic iron plate is 0.8 or more and less than 1.

4. The laminated core according to any one of claims 1 to 3, A laminated core, characterized in that the second soft magnetic iron plate has a saturation magnetic flux density of 2.0 T or more.

5. The laminated core according to any one of claims 1 to 4, The thickness of the first soft magnetic iron plate and the second soft magnetic iron plate is 0.01 mm or more and 1 mm or less, A laminated core, characterized in that the thickness of the first soft magnetic iron plate is between 1 and 5 times the thickness of the second soft magnetic iron plate.

6. The laminated core according to any one of claims 1 to 5, A laminated core, characterized in that the soft magnetic iron plate of the outermost layer has a magnetostriction constant equal to or less than the magnetostriction constants of the other soft magnetic iron plates.

7. 7. The laminated core according to claim 6, A laminated core, characterized in that the soft magnetic iron plate of the outermost layer is a third soft magnetic iron plate different from the first soft magnetic iron plate and the second soft magnetic iron plate.

8. The laminated core according to any one of claims 1 to 7, Between the adjacent soft magnetic iron plates, 1×10 6 A laminated core characterized by the presence of an electrical insulating layer having an electrical resistivity of Ω·cm or more.

9. A rotating electric machine having a laminated core, A rotating electric machine, comprising the laminated core according to any one of claims 1 to 8.

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