Laminated iron core and method for manufacturing same

Abstract

Provided are: a laminated iron core in which an Fe-N-based alloy plate is used as a soft magnetic material plate, and an electrically insulating layer / interlayer insulation layer are formed and laminated while maintaining the magnetic properties of the Fe-N-based alloy plate; and a method for manufacturing the same. A laminated iron core according to the present invention is a laminated iron core in which a plurality of soft magnetic material plates are laminated with an electrically insulation layer therebetween, the laminated iron core being characterized in that: the soft magnetic material plates are Fe–N-based alloy plates containing Fe as a main component and containing a N component; the electrically insulation layer is a layer having a predetermined resin material as a matrix; and the predetermined resin material is at least one selected from an epoxy adhesive, a dimethacrylate adhesive, an acrylic adhesive, an ene–thiol adhesive, and a methacrylate ester adhesive.

Description

Laminated Core and Method for Manufacturing the Same

[0001] The present invention relates to a technology of cores using soft magnetic materials, and particularly to a laminated core formed by laminating a plurality of soft magnetic material plates, and a method for manufacturing the laminated core.

[0002] In electromechanical devices (for example, rotating electrical machines and transformers), laminated cores formed by laminating a plurality of soft magnetic material plates (for example, electromagnetic pure iron plates and electromagnetic steel plates, with a thickness of 0.01 to 3 mm) are widely used. From the perspective of global environmental protection, the application fields of electromechanical devices using soft magnetic materials have been expanding in recent years, and along with this, the requirements for higher output and higher efficiency of these electromechanical devices have been increasing.

[0003] Assuming a rotating electrical machine as an electromechanical device, its output is proportional to the product of the torque and the rotational speed during operation. Therefore, higher output can be achieved by increasing either the torque or the rotational speed. The torque is proportional to the product of the magnetic flux density and the current value. To increase the torque, it is desirable to use a soft magnetic material that achieves a high saturation magnetic flux density Bs and / or a high saturation magnetization Ms. And in order to increase Bs / Ms, various composition controls and microstructure controls of soft magnetic materials have been carried out.

[0004] When increasing the rotational speed during operation, the conversion efficiency between electrical energy and magnetic energy is important, and reducing the loss (iron loss Pi) in the soft magnetic material plate becomes an issue. The reduction of Pi also leads to suppressing heat generation during operation. Pi is the sum of the hysteresis loss and the eddy current loss. To reduce the hysteresis loss, it is desirable that the coercive force Hc is small, and to reduce the eddy current loss, increasing the electrical resistance or thinning the plate is effective.

[0005] Currently, electromagnetic steel plates of Fe-Si (iron - silicon) alloy systems are widely used as materials with a relatively good balance between a relatively high Bs / Ms and a relatively low Pi. As a material showing a higher Bs than the Fe-Si alloy system electromagnetic steel plate, Fe-N (nitrogen) alloy plates are known.

[0006] For example, Patent Document 1 (JP 2003-277893) describes an electrical steel sheet with excellent magnetic properties, characterized by containing 0.05 to 8.0% N by mass and having a sheet thickness of 0.010 mm or more and 1.0 mm or less. Furthermore, it is stated that the electrical steel sheet in Patent Document 1 preferably contains 0.1% or more Mn, 3.5% or less Si, 2.0% or less Al, 0.2% or less Ti, 0.02% or less B, 10% or less Cr, 0.5 to 5.0% Ni, and 0.050% or less by mass.

[0007] On the other hand, in order to effectively utilize the thinning of soft magnetic materials to reduce eddy current losses in laminated iron cores, it is important to properly ensure electrical insulation and interlayer insulation between the soft magnetic material plates that make up the laminated iron core. One method for ensuring electrical insulation and interlayer insulation is to prepare soft magnetic material plates with an oxide-based insulating material formed on their surface in advance and then laminate them.

[0008] For example, Patent Document 2 (WO 2018 / 079845 A1) teaches a grain-oriented electrical steel sheet having a steel sheet and an insulating coating formed on the surface of the steel sheet, wherein the insulating coating contains a metal phosphate salt and colloidal silica, with the colloidal silica in an amount of 20 to 150 parts by mass per 100 parts by mass of the metal phosphate salt, and further contains 0.5 to 7 parts by mass of one or more fine particles selected from silicon carbide, silicon nitride, aluminum nitride, boron nitride, sialon, and cordierite per 100 parts by mass of the metal phosphate salt, with an average particle size of 0.3 to 7.0 μm, a crystallinity of the metal phosphate salt of 2 to 40%, and no chromium.

[0009] Japanese Patent Publication No. 2003-277893, International Publication No. 2018 / 079845

[0010] According to Patent Document 1, by nitriding conventionally known electrical steel sheets to achieve an unprecedentedly high N content, it is possible to achieve both high magnetic flux density and low iron loss. Furthermore, as an example of conditions for gas nitriding, it is stated that it is preferable to hold the sheet in an atmosphere containing 2% or more ammonia at a temperature range of 580 to 800°C.

[0011] According to Patent Document 2, it is possible to provide a grain-oriented electrical steel sheet with good magnetic properties, having an insulating coating that has good adhesion and corrosion resistance, and can impart significantly higher tension to the steel sheet than conventional materials. Furthermore, it is stated that the soaking temperature during the baking process is preferably in the range of 800 to 1000°C.

[0012] According to the inventors' research, it has been found that Fe-N alloy materials may begin to lose their nitrogen component (denitrification) when exposed to environments above 400°C. From this perspective, when Patent Documents 1 and 2 are combined, there is a concern that the nitrogen component nitrided using the technology of Patent Document 1 may detach during the formation of the insulating film using the technology of Patent Document 2, making it impossible to maintain the desired magnetic properties.

[0013] The present invention was made to address the above-mentioned problems. Therefore, the primary object of the present invention is to provide a laminated iron core in which an electrical insulating layer / interlayer insulating layer is formed and laminated while maintaining the magnetic properties of the Fe-N alloy plate, using an Fe-N alloy plate as the soft magnetic material plate, and a method for manufacturing the laminated iron core.

[0014] (I) One aspect of the present invention provides a laminated iron core in which a plurality of soft magnetic material plates are laminated with an electrical insulating layer in between, wherein the soft magnetic material plates are Fe-N alloy plates mainly composed of Fe and containing an N component, the electrical insulating layer is a layer having a predetermined resin material as a matrix and containing 50 volume% or less of spherical or fibrous spacer particles, and the resin material is one or more selected from epoxy adhesives, dimethacrylate adhesives, acrylic adhesives, ene-thiol adhesives, and methacrylic acid ester adhesives.

[0015] The present invention allows for the following improvements and modifications to be freely combined in the laminated iron core (I) according to the present invention described above: (i) The resin material has a glass transition temperature of 80°C or higher. (ii) The spacer particles are one or more selected from SiO2 (silicon oxide), ZrO2 (zirconium oxide), Al2O3 (aluminum oxide), Nb2O5 (niobium oxide), ZrSiO4 (zirconium silicate), Zr2(WO4)(PO4)2 (zirconium tungstate phosphate), 2MgO・2Al2O3・5SiO2 (cordierite), 3Al2O3・2SiO2 (mullite), LiAlSiO4 (eucryptite), SiO2-Na2O-CaO glass (soda glass), and SiO2-B2O3-Na2O-Al2O3 glass (borosilicate glass). (iii) When the spacer particles are spherical, D90 is 20 μm or less, and when the spacer particles are fibrous, the average diameter is 20 μm or less and the aspect ratio is 100 or less. (iv) The soft magnetic material plate has alignment grooves formed on it.

[0016] (II) Another aspect of the present invention is a method for manufacturing a laminated iron core, wherein the laminated iron core is any of the above-described laminated iron cores, and the manufacturing method comprises: a soft magnetic material plate preparation step of preparing the soft magnetic material plates; a resin paste preparation step of preparing a resin paste that will be the basis of the electrical insulating layer; a resin paste application step of applying the resin paste to at least one main surface of the soft magnetic material plates; a soft magnetic material plate laminate formation step of laminating the soft magnetic material plates to which the resin paste has been applied to form a soft magnetic material plate laminate; and a laminated iron core formation step of curing the resin paste of the soft magnetic material plate laminate to form the electrical insulating layer and form the laminated iron core.

[0017] The present invention allows for the following improvements and modifications to be freely combined in the above-described method for manufacturing a laminated iron core (II) according to the present invention: (v) The resin paste preparation step includes a spacer particle mixing step of mixing the spacer particles so that they are uniformly dispersed in the resin paste. (vi) The resin paste application step is a full-surface resin paste application step of applying the resin paste to the entire surface of at least one main surface of the soft magnetic material plate. (vii) The resin paste application step is a partial resin paste application step of partially applying the resin paste to at least one main surface of the soft magnetic material plate so that the resin paste is scattered. (viii) The resin paste application step includes a full-surface resin paste application step of applying the resin paste to the entire surface of at least one main surface of the soft magnetic material plate, and a spacer particle embedding and placement step of embedding and arranging the spacer particles so that they are uniformly distributed on the resin paste application surface. (ix) The resin paste coating step includes a partial resin paste coating step of partially coating the resin paste on at least one main surface of the soft magnetic material plate so that the resin paste is scattered, and a spacer particle embedding and placement step of embedding and arranging the spacer particles so that they are uniformly distributed on the coated surface of the resin paste. (x) The soft magnetic material plate preparation step includes an alignment unevenness forming step of forming the alignment unevenness on the soft magnetic material plate.

[0018] According to the present invention, it is possible to provide a laminated iron core in which an electrical insulating layer / interlayer insulating layer is formed and laminated while maintaining the magnetic properties of the Fe-N alloy plate, using an Fe-N alloy plate as the soft magnetic material plate, and a method for manufacturing the laminated iron core. Problems, configurations, and effects other than those mentioned above will be clarified by the description of the embodiments below.

[0019] This is a schematic cross-sectional diagram showing an example of the structure of a laminated core according to the present invention. This is a schematic cross-sectional diagram showing another example of the structure of a laminated core according to the present invention. This is a schematic cross-sectional diagram showing another example of the structure of a laminated core according to the present invention. This is a schematic flowchart showing an example of a method for manufacturing a laminated core according to the present invention. This is a schematic flowchart showing another example of a method for manufacturing a laminated core according to the present invention. This is a schematic flowchart showing another example of a method for manufacturing a laminated core according to the present invention. This is a schematic flowchart showing another example of a method for manufacturing a laminated core according to the present invention.

[0020] Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the present invention is not limited to the specific embodiments described, and it is possible to combine it with or improve upon prior art without departing from the technical spirit of the invention.

[0021] [Laminated Iron Core of the Present Invention] Figure 1A is a schematic cross-sectional view showing an example of the structure of a laminated iron core according to the present invention, Figure 1B is a schematic cross-sectional view showing another example of the structure of a laminated iron core according to the present invention, and Figure 1C is a schematic cross-sectional view showing another example of the structure of a laminated iron core according to the present invention. The laminated iron cores 10a to 10c according to the present invention are made by laminating a plurality of soft magnetic material plates 1 made of Fe-N alloy with an electrical insulating layer 2 having a predetermined resin material as the matrix.

[0022] As shown in Figures 1A to 1C, in order to simplify the control of the thickness of the electrical insulating layer 2 (control of the spacing between the layers of the soft magnetic material plates 1), it is preferable that spherical or short fiber-shaped spacer particles 3 are mixed into the electrical insulating layer 2 in the laminated iron cores 10a to 10c according to the present invention.

[0023] As shown in Figure 1B, the laminated iron core 10b contains void regions 4 within the electrical insulating layer 2. In other words, the electrical insulating layer 2 between the laminated soft magnetic material plates 1 does not need to be filled with resin material. When void regions 4 are present, it is preferable that the void regions 4 are finely dispersed within the electrical insulating layer 2. By finely dispersing the void regions 4 within the electrical insulating layer 2, it is possible to ensure electrical insulation between the laminated soft magnetic material plates 1 while mitigating the concentration of thermal stress, which has the advantage of improving resistance to thermal cycling.

[0024] The size of the void region 4 is preferably 20 μm or less in terms of the average diameter of the equivalent area circle observed in cross-section, and its presence is preferably 20 area % or less in terms of the area ratio within the electrical insulating layer 2 observed in cross-section. The size of the void region 4 is more preferably 15 μm or less in terms of the average diameter of the equivalent area circle, and even more preferably 10 μm or less. The presence of the void region 4 is more preferably 15 area % or less in terms of the area ratio within the electrical insulating layer 2, and even more preferably 10 area % or less.

[0025] As shown in Figure 1C, the laminated core 10c has alignment grooves 5 formed on the soft magnetic material plates 1c to facilitate alignment when laminating the soft magnetic material plates. When manufacturing a laminated core by laminating many thin soft magnetic material plates, aligning each soft magnetic material plate requires considerable effort. From this perspective, the laminated core 10c using soft magnetic material plates 1c having alignment grooves 5 can significantly reduce the effort required for lamination, and has the advantage of contributing to a reduction in assembly costs.

[0026] There are no particular limitations on the shape of the alignment grooves 5 of the soft magnetic material plate 1c; for example, a spherical shape or a frustoconical shape can be suitably used. Spherical and frustoconical shapes have the advantage that they converge to the appropriate positional relationship through a self-alignment action when overlapped and pressed.

[0027] Next, each component of the laminated iron core according to the present invention will be described in detail.

[0028] (Soft Magnetic Material Plate) The soft magnetic material plate 1 is an Fe-N alloy material plate whose magnetic properties are improved by nitriding treatment, with Fe as the main component (50 atomic percent or more). There are no particular limitations as long as it can be used as a laminated iron core for electromechanical devices, and conventional materials can be used as appropriate. For example, alloy material plates obtained by nitriding treatment of electromagnetic pure iron plates or Fe-Si electromagnetic steel plates, or alloy material plates obtained by nitriding treatment of Fe-Co (cobalt) alloy plates can be used.

[0029] There are no particular limitations on the N content of the soft magnetic material plate 1; any N content that yields the desired magnetic properties is acceptable. For example, it is preferable to control the N content within a range of 0.1 atomic% to 10 atomic%.

[0030] (Resin material for the electrical insulating layer) The electrical insulating layer 2 is a layer with a predetermined resin material as its matrix. The predetermined resin material used in the present invention is preferably one or more selected from epoxy adhesives, dimethacrylate adhesives, acrylic adhesives, ene-thiol adhesives, and methacrylate ester adhesives, and is more preferably an adhesive having a glass transition temperature of 80°C or higher. For example, methacrylate ester adhesives have a glass transition temperature of 145°C.

[0031] These resin materials can form an electrical insulating layer 2 without heating to 400°C, thus preventing denitrification from the soft magnetic material plate 1 and preventing a decrease in magnetic properties due to denitrification. Furthermore, since the soft magnetic material plates 1 can be laminated and bonded together while forming the electrical insulating layer 2 on the soft magnetic material plate 1, electrical insulation / interlayer insulation and integration (integral bonding) of the entire laminated core can be achieved simultaneously. The resulting laminated core has the advantages of being easy to miniaturize and resistant to mechanical vibration.

[0032] (Spacer particles) As mentioned above, in order to simplify the control of the thickness of the electrical insulating layer 2 (control of the stacking interval of the soft magnetic material plate 1), it is preferable that spherical or fibrous spacer particles 3 are mixed into the electrical insulating layer 2. The mixing ratio of spacer particles 3 is preferably 50 volume% or less of the electrical insulating layer 2, more preferably 20 volume% or less, and even more preferably 10 volume% or less.

[0033] The material for the spacer particles 3 is preferably one or more selected from SiO2, ZrO2, Al2O3, Nb2O5, ZrSiO4, Zr2(WO4)(PO4)2, 2MgO・2Al2O3・5SiO2, 3Al2O3・2SiO2, LiAlSiO4, SiO2-Na2O-CaO glass, and SiO2-B2O3-Na2O-Al2O3 glass.

[0034] The size of the spacer particles 3 is preferably such that, when the spacer particles 3 are spherical (ratio of short diameter to long diameter is 0.8 or more), the D90 (90% diameter, the particle size that accounts for 90% of the volume in the cumulative distribution when the particle size distribution is measured) is 20 μm or less, more preferably 10 μm or less, and even more preferably 5 μm or less. Furthermore, when the spacer particles 3 are fibrous, the average diameter is preferably 20 μm or less and the aspect ratio (aspect ratio = average length / average diameter) is preferably 100 μm or less and the aspect ratio is preferably 200 or less, and even more preferably 5 μm or less and the aspect ratio is preferably 400 or less.

[0035] [Method for Manufacturing a Laminated Iron Core According to the Present Invention] Figure 2 is a schematic flowchart showing an example of a method for manufacturing a laminated iron core according to the present invention. As shown in Figure 2, first, a soft magnetic material plate preparation step S1 is performed to prepare a soft magnetic material plate 1, and a resin paste preparation step S2 is performed to prepare a resin paste that will be the basis for the electrical insulating layer 2. The order of steps S1 and S2 does not matter.

[0036] The soft magnetic material plate preparation step S1 is not particularly limited as long as an Fe-N alloy material plate exhibiting the desired magnetic properties can be prepared. This can be done by purchasing the Fe-N alloy material plate, or by performing a nitriding treatment step S1a on an Fe-based material plate that does not contain an N component.

[0037] Furthermore, as part of this process S1, a soft magnetic material plate shaping process S1b may be performed to process the soft magnetic material plate 1 into a desired shape. There are no particular limitations on the method of shaping the soft magnetic material plate 1, and conventional metalworking methods (for example, punching to form teeth, pressing to form alignment grooves 5) can be used as appropriate. The order of the soft magnetic material plate shaping process S1b and the nitriding process S1a is not restricted.

[0038] The resin paste preparation step S2 is not particularly limited as long as it prepares a resin paste that can be applied onto the soft magnetic material plate 1. Furthermore, as part of this step S2, a spacer particle mixing step S2a may be performed, in which spacer particles 3 are mixed into the resin paste. In the spacer particle mixing step S2a, it is preferable to mix in spacer particles 3 at a rate of 1% to 50% by volume.

[0039] Next, a resin paste coating step S3 is performed, in which a resin paste is applied to at least one main surface of the soft magnetic material plate 1. In the manufacturing method shown in Figure 2, a full-surface resin paste coating step S3a is assumed, in which the resin paste is applied to the entire surface of the main surface. As long as the thickness of the resin paste film applied on the surface of the soft magnetic material plate 1 (e.g., on the order of μm) can be controlled, there are no particular limitations on the coating method, and methods such as the doctor blade method can be suitably used.

[0040] Furthermore, if the resin material used in the resin paste is a two-component adhesive, one of the two-component liquids may be applied to one main surface of one soft magnetic material plate 1, and the other of the two-component liquids may be applied to the opposing surface of the adjacent soft magnetic material plate 1 during lamination.

[0041] Next, a soft magnetic material plate laminate formation step S4 is performed, in which soft magnetic material plates 1 coated with resin paste are laminated to form a soft magnetic material plate laminate. At this time, it is preferable to apply pressure in the lamination direction from the viewpoint of ensuring adhesion between the laminated soft magnetic material plates 1 and controlling the thickness of the electrical insulation layer 2 (controlling the lamination spacing of the soft magnetic material plates 1). However, in order to suppress unwanted deformation of the laminated soft magnetic material plates 1, it is desirable to control the surface pressure within an appropriate range (for example, 5 kPa or more and 100 kPa or less).

[0042] Next, a laminated core forming step S5 is performed, in which the resin paste of the soft magnetic material plate laminate is cured to form an electrical insulating layer 2 and to form a laminated core. There are no particular limitations on the curing method of the resin paste, and a curing method suitable for the resin material used in the resin paste may be used as appropriate. In addition, if necessary, a core shape finishing step S5a, which finishes the shape of the laminated core, may be performed as part of this step S5.

[0043] Figure 3 is a schematic flowchart showing another example of a method for manufacturing a laminated iron core according to the present invention. The manufacturing method shown in Figure 3 differs from the manufacturing method in Figure 2 in that, in the resin paste coating step S3, instead of the full-surface resin paste coating step S3a, a partial resin paste coating step S3b is performed in which the resin paste is partially applied to at least one main surface of the soft magnetic material plate 1 so that it is dotted, but all other steps are the same.

[0044] In the partial resin paste coating step S3b, by controlling the coating amount and coating position of the resin paste, a laminated core 10b including a void region 4 can be manufactured within the electrical insulation layer 2. There is no particular limitation on the partial coating method (control of the coating amount and coating position of the resin paste) in this step S3b. For example, a computer-controlled dispenser or the like can be preferably used.

[0045] FIG. 4 is a schematic flowchart showing another example of the method for manufacturing a laminated core according to the present invention. The manufacturing method shown in FIG. 4 is different from the manufacturing method shown in FIG. 2 in that, instead of performing the spacer particle mixing step S2a in the resin paste preparation step S2, a spacer particle embedding and arranging step S3c of embedding and arranging spacer particles 3 in the applied resin paste is performed as part of the resin paste coating step S3, and the rest is the same.

[0046] In the spacer particle embedding and arranging step S3c, it is preferable to embed and arrange the spacer particles 3 in a range of less than 1% by volume with respect to the electrical insulation layer 2. There is no particular limitation on the position where the spacer particles 3 are embedded and arranged. However, from the viewpoint of facilitating the control of the interval between the soft magnetic material plates 1 / the thickness of the electrical insulation layer 2 in the laminated core and preventing unevenness when pressurized in the lamination direction, it is preferable to arrange them so as to be uniformly distributed within the plane of the soft magnetic material plate 1.

[0047] FIG. 5 is a schematic flowchart showing another example of the method for manufacturing a laminated core according to the present invention. The manufacturing method shown in FIG. 5 combines the manufacturing methods shown in FIGS. 3 and 4. It is different in that, instead of the spacer particle mixing step S2a and the resin paste full-surface coating step S3a, the resin paste partial coating step S3b and the spacer particle embedding and arranging step S3c are performed, and the rest is the same as the manufacturing method shown in FIG. 2.

[0048] Hereinafter, the present invention will be described more specifically through various experiments. However, the present invention is not limited to the configurations and structures described in these experiments.

[0049] [Experiment 1] (Fabrication of a simulated laminated iron core of Example 1) As the soft magnetic material plate preparation step S1, Fe-Co-N alloy material plates were prepared. Specifically, commercially available Fe-20 atomic%Co alloy plates were punched to prepare multiple starting material plates of the size "20 mm × 20 mm × 0.1 mm" (soft magnetic material plate shaping step S1b). Next, the shaped starting material plates were subjected to nitriding treatment (heating at 900°C in an ammonia gas atmosphere → water quenching → ultra-subzero treatment → tempering at 120°C for 48 hours in an N2 gas atmosphere) to prepare Fe-Co-N alloy material plates (nitriding treatment step S1a).

[0050] In the resin paste preparation step S2, a resin paste was prepared using a methacrylic acid ester resin. Specifically, a methacrylic acid ester adhesive was used as the resin material, and spherical SiO2 powder particles (D90 ≈ 2 μm) were used as spacer particles. The materials were weighed and uniformly mixed so that the ratio of "resin material:spacer particles = 95 volume%:5 volume%" (spacer particle mixing step S2a).

[0051] Next, the resin paste prepared in step S2 was applied to the entire surface of one of the main surfaces of the soft magnetic material plates prepared in step S1 to a thickness of approximately 2 μm (resin paste full surface application step S3a). Five of these coated soft magnetic material plates were then stacked and subjected to a load of 30 kPa (soft magnetic material plate laminate formation step S4). The load was maintained at room temperature for 3 hours to cure the resin paste, thereby producing the simulated laminated core of Example 1 (laminated core formation step S5).

[0052] [Experiment 2] (Investigation of the magnetic properties of the simulated laminated iron core of Example 1) The magnetic properties of the sample were investigated using a vibrating sample magnetometer (BHV-525H, manufactured by RIKEN Electron Co., Ltd.). The magnetization (unit: emu) of the sample was measured under conditions of a magnetic field of 1.6 MA / m and a temperature of 20°C, and the saturation magnetization Ms (unit: emu / g) was determined from the sample mass. The accuracy of this measurement is approximately "±1 emu / g". In other words, a difference of "3 emu / g or more" can be considered statistically significant.

[0053] First, the magnetic properties of the Fe-Co-N alloy material plate and the original starting material plate prepared in Experiment 1 were investigated. As a result, the starting material plate had a magnetic density of "Ms = 234 emu / g", while the Fe-Co-N alloy material plate had a magnetic density of "Ms = 237 emu / g". The difference of "3 emu / g" confirmed that the magnetic properties were improved by the nitriding treatment.

[0054] Next, the magnetic properties of the simulated laminated core of Example 1 were investigated. As a result, it was confirmed that the simulated laminated core of Example 1 had a magnetic field of "Ms = 236.8 emu / g", exhibiting magnetic properties equivalent to those of the Fe-Co-N alloy material plate mentioned earlier. In other words, it was confirmed that a laminated core can be obtained by forming an electrical insulating layer and laminating it while maintaining the magnetic properties of the Fe-Co-N alloy plate.

[0055] [Experiment 3] (Fabrication of a simulated laminated iron core of Example 2) As the soft magnetic material plate preparation step S1, Fe-Co-N alloy material plates were prepared. Specifically, commercially available Fe-10 atomic%Co alloy plates were punched to prepare multiple starting material plates of the size "20 mm × 20 mm × 0.26 mm" (soft magnetic material plate shaping step S1b). Next, the shaped starting material plates were subjected to the same nitriding treatment as in Experiment 1 to prepare Fe-Co-N alloy material plates (nitriding treatment step S1a).

[0056] In the resin paste preparation step S2, a resin paste was prepared using a methacrylic acid ester resin. Specifically, a methacrylic acid ester adhesive was used as the resin material, and spherical SiO2 powder particles (D90 ≈ 5 μm) were used as spacer particles. The materials were weighed and uniformly mixed so that the ratio of "resin material:spacer particles = 95 volume%:5 volume%" (spacer particle mixing step S2a).

[0057] Next, the resin paste prepared in step S2 was partially applied to one main surface of the soft magnetic material plate prepared in step S1 to a thickness of approximately 5 μm so that it was scattered (partial resin paste application step S3b). Five of these coated soft magnetic material plates were then stacked and a load of 30 kPa was applied (soft magnetic material plate stacking step S4). The load was then maintained at room temperature for 3 hours to cure the resin paste, thereby producing the simulated stacked core of Example 2 (stacked core formation step S5).

[0058] [Experiment 4] (Investigation of magnetic properties of the simulated laminated iron core of Example 2) The magnetic properties of the samples were investigated in the same manner as in Experiment 2. First, the magnetic properties of the Fe-Co-N alloy material plate and the original starting material plate prepared in Experiment 3 were investigated. As a result, the starting material plate had "Ms = 225 emu / g", while the Fe-Co-N alloy material plate had "Ms = 228 emu / g". The difference was "3 emu / g", confirming that the magnetic properties were improved by the nitriding treatment.

[0059] Next, the magnetic properties of the simulated laminated core of Example 2 were investigated. As a result, it was confirmed that the simulated laminated core of Example 2 had a magnetic field of "Ms = 227.8 emu / g", exhibiting magnetic properties equivalent to those of the Fe-Co-N alloy material plate mentioned earlier. In other words, it was confirmed that a laminated core can be obtained by forming an electrical insulating layer and laminating it while maintaining the magnetic properties of the Fe-Co-N alloy plate.

[0060] The embodiments and experiments described above are explained to aid in understanding the present invention, and the present invention is not limited to the specific configurations described. For example, it is possible to replace some of the configurations of the embodiments with configurations that are common knowledge to those skilled in the art, and it is also possible to add configurations that are common knowledge to those skilled in the art to the configurations of the embodiments. In other words, the present invention allows for the deletion, substitution, and addition of some of the configurations of the embodiments and experiments specified herein, as long as it does not depart from the technical spirit of the invention.

[0061] 10a to 10c...Laminated iron core, 1, 1c...Soft magnetic plate, 2...Electrical insulating layer, 3...Spacer particles, 4...Void region, 5...Rubber and groove portion for alignment.

Claims

1. A laminated iron core comprising a plurality of soft magnetic material plates laminated with an electrical insulating layer in between, wherein the soft magnetic material plates are Fe-N alloy plates mainly composed of Fe and containing an N component, the electrical insulating layer is a layer having a predetermined resin material as a matrix and containing 50 volume% or less of spherical or fibrous spacer particles, and the resin material is one or more selected from epoxy adhesives, dimethacrylate adhesives, acrylic adhesives, ene-thiol adhesives, and methacrylate ester adhesives.

2. A laminated iron core according to claim 1, characterized in that the resin material has a glass dislocation temperature of 80°C or higher.

3. A laminated iron core according to claim 1, characterized in that the spacer particles are one or more selected from SiO2, ZrO2, Al2O3, Nb2O5, ZrSiO4, Zr2(WO4)(PO4)2, 2MgO・2Al2O3・5SiO2, 3Al2O3・2SiO2, LiAlSiO4, SiO2-Na2O-CaO glass, and SiO2-B2O3-Na2O-Al2O3 glass.

4. A laminated iron core according to claim 2, characterized in that the spacer particles are one or more selected from SiO2, ZrO2, Al2O3, Nb2O5, ZrSiO4, Zr2(WO4)(PO4)2, 2MgO・2Al2O3・5SiO2, 3Al2O3・2SiO2, LiAlSiO4, SiO2-Na2O-CaO glass, and SiO2-B2O3-Na2O-Al2O3 glass.

5. A laminated iron core according to claim 3, characterized in that, when the spacer particles are spherical, D90 is 20 μm or less, and when the spacer particles are fibrous, the average diameter is 20 μm or less and the aspect ratio is 100 or less.

6. A laminated iron core according to claim 4, characterized in that, when the spacer particles are spherical, D90 is 20 μm or less, and when the spacer particles are fibrous, the average diameter is 20 μm or less and the aspect ratio is 100 or less.

7. A laminated iron core according to any one of claims 1 to 6, characterized in that the soft magnetic material plate has alignment-oriented protrusions formed thereon.

8. A method for manufacturing a laminated iron core, wherein the laminated iron core is the laminated iron core according to any one of claims 1 to 6, and the manufacturing method comprises: a soft magnetic material plate preparation step of preparing the soft magnetic material plates; a resin paste preparation step of preparing a resin paste that will be the basis of the electrical insulating layer; a resin paste application step of applying the resin paste to at least one main surface of the soft magnetic material plates; a soft magnetic material plate laminate formation step of forming a soft magnetic material plate laminate by laminating the soft magnetic material plates to which the resin paste has been applied; and a laminated iron core formation step of forming the laminated iron core by curing the resin paste of the soft magnetic material plate laminate to form the electrical insulating layer.

9. A method for manufacturing a laminated iron core according to claim 8, characterized in that the resin paste preparation step includes a spacer particle mixing step of mixing the spacer particles so as to be uniformly dispersed in the resin paste.

10. A method for manufacturing a laminated iron core according to claim 9, characterized in that the resin paste coating step is a full-surface resin paste coating step in which the resin paste is applied to the entire surface of at least one main surface of the soft magnetic material plate.

11. A method for manufacturing a laminated iron core according to claim 9, characterized in that the resin paste coating step is a partial resin paste coating step in which the resin paste is partially coated on at least one main surface of the soft magnetic material plate so as to be scattered.

12. A method for manufacturing a laminated iron core according to claim 8, wherein the resin paste coating step includes a full-surface resin paste coating step of coating the resin paste over the entire surface of at least one main surface of the soft magnetic material plate, and a spacer particle embedding and placement step of embedding and arranging the spacer particles so as to be uniformly distributed on the coated surface of the resin paste.

13. A method for manufacturing a laminated iron core according to claim 8, wherein the resin paste coating step includes a partial resin paste coating step of partially coating the resin paste on at least one main surface of the soft magnetic material plate so that the resin paste is scattered, and a spacer particle embedding and placement step of embedding and arranging the spacer particles so that they are uniformly distributed on the coated surface of the resin paste.

14. A method for manufacturing a laminated iron core, wherein the laminated iron core is the laminated iron core described in claim 7, and the manufacturing method comprises: a soft magnetic material plate preparation step of preparing the soft magnetic material plate; a resin paste preparation step of preparing a resin paste that will be the basis for the electrical insulating layer; a resin paste application step of applying the resin paste to at least one main surface of the soft magnetic material plate; a soft magnetic material plate laminate formation step of forming a soft magnetic material plate laminate by laminating the soft magnetic material plate coated with the resin paste; and a laminated iron core formation step of curing the resin paste of the soft magnetic material plate laminate to form the electrical insulating layer and form the laminated iron core, wherein the soft magnetic material plate preparation step includes an alignment unevenness forming step of forming the alignment unevenness on the soft magnetic material plate.

15. A method for manufacturing a laminated iron core according to claim 14, characterized in that the resin paste preparation step includes a spacer particle mixing step of mixing the spacer particles so as to be uniformly dispersed in the resin paste.

16. A method for manufacturing a laminated iron core according to claim 15, characterized in that the resin paste coating step is a full-surface resin paste coating step in which the resin paste is applied to the entire surface of at least one main surface of the soft magnetic material plate.

17. A method for manufacturing a laminated iron core according to claim 15, characterized in that the resin paste coating step is a partial resin paste coating step in which the resin paste is partially coated on at least one main surface of the soft magnetic material plate so as to be scattered.

18. A method for manufacturing a laminated iron core according to claim 14, wherein the resin paste coating step includes a full-surface resin paste coating step of coating the resin paste over the entire surface of at least one main surface of the soft magnetic material plate, and a spacer particle embedding and placement step of embedding and arranging the spacer particles so as to be uniformly distributed on the coated surface of the resin paste.

19. A method for manufacturing a laminated iron core according to claim 14, wherein the resin paste coating step includes a partial resin paste coating step of partially coating the resin paste on at least one main surface of the soft magnetic material plate so that the resin paste is scattered, and a spacer particle embedding and placement step of embedding and arranging the spacer particles so that they are uniformly distributed on the coated surface of the resin paste.

Images