Fe-based soft magnetic amorphous alloy sheet, method for manufacturing the same, laminated core, and rotary electric machine

Abstract

This invention provides a Fe-based soft magnetic amorphous alloy sheet capable of easily reducing losses in laminated iron cores, a laminated iron core and a rotary motor using the sheet, and a method for manufacturing the Fe-based soft magnetic amorphous alloy sheet. The Fe-based soft magnetic amorphous alloy sheet for laminated iron cores of this invention is characterized in that the sheet has: opposing front and back sides; and side sides, the sheet thickness is 10–50 μm, the side sides have fracture surfaces inclined relative to the thickness direction of the sheet from the front and back sides respectively, and the side sides are V-shaped in cross-section in the thickness direction of the sheet, gradually tapering towards the ends.

Description

Technical Field

[0001] This invention relates to Fe-based soft magnetic amorphous alloy thin plates, laminated iron cores and rotary motors using the thin plates, and a method for manufacturing Fe-based soft magnetic amorphous alloy thin plates. Background Technology

[0002] Rotary motors used in electric vehicles and hybrid electric vehicles require reduced losses due to the high-frequency alternating magnetic flux caused by high-speed rotation to ensure efficient operation. To date, the efficiency of rotary motors has been continuously improved through the use of inverters, the application of rare-earth magnets, and optimization of structural design. However, further improvements in efficiency require reducing the iron losses of the laminated cores used in the magnetic poles. Therefore, the demand for low-loss magnetic materials, such as Fe-based soft magnetic amorphous alloys, Fe-based nanocrystalline soft magnetic alloys containing fine bcc structures of Fe crystalline or FeSi crystalline and amorphous phases, is increasing, replacing the electromagnetic steel sheets previously used in laminated cores.

[0003] Fe-based soft magnetic amorphous alloys, such as the known Fe-Si-B series soft magnetic alloys, can be manufactured by supercooling molten metal with a specified composition using methods such as single-roll liquid quenching to amorphize it. METGLAS (registered trademark) 2605HB1M, 2605SA1 and the Fe-Si-B-Cr series 2605SA3 from METGLAS, Inc. are commercially available.

[0004] In addition, Fe-based nanocrystalline soft magnetic alloys are obtained by heat-treating amorphous ribbons, similar to those obtained for Fe-based soft magnetic amorphous alloys, to precipitate Fe or FeSi crystalline phases (nanocrystallineization). Examples include Hitachi Metals Corporation's FINEMET (registered trademark) FT-3M and VITROPERM (registered trademark) 800 (Fe-Si-B-Cu-Nb system) and MAGNETEC Gesellschaft fur Magnettechnologie mbH's NANOPERM (registered trademark) (Fe-B-Zr-Cu system).

[0005] All of the above materials are supplied in the form of strips, ribbons, films, or foils, typically in long strips with a thickness of ten to tens of μm. These Fe-based soft magnetic amorphous alloy or Fe-based nanocrystalline soft magnetic alloy strips are thinner than electromagnetic steel sheets, which reduces eddy current losses. Furthermore, compared to electromagnetic steel sheets, Fe-based soft magnetic amorphous alloys or Fe-based nanocrystalline soft magnetic alloys have lower hysteresis losses, and laminated cores using these strips exhibit excellent soft magnetic properties.

[0006] On the other hand, Fe-based soft magnetic amorphous alloys, which contain precursors of Fe-based nanocrystalline soft magnetic alloys, are known to be ideal elastoplastic materials that generally do not exhibit strain hardening. They possess large plastic deformation capacity and high toughness, but under uniaxial stress conditions such as tensile tests, they appear difficult to elongate. Such Fe-based soft magnetic amorphous alloy strips are very hard and, compared to crystalline electromagnetic steel sheets, have poor machinability, which is a major reason why applications requiring the strip to be machined into specified shapes for laminated iron cores have not progressed. Therefore, in addition to blanking (hereinafter referred to as blanking only, to distinguish it from other processing techniques) using a die consisting of a punch and a stamping device, various processing techniques for obtaining thin sheets of specified shapes from strips, such as chemical etching, laser processing, and wire electrode electrical discharge machining, have been studied.

[0007] Patent Document 1 discloses a punching process for amorphous metal foil. By using a servo press to punch the amorphous metal foil at a specified punching speed, the generation of burrs associated with plastic deformation is suppressed. Patent Document 2 discloses an etching process for amorphous alloy strips. By pre-forming crystallized regions in a specified shape on the strip and then etching these crystallized regions, the etching speed is accelerated. This improves the productivity of the etching process.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Application Publication No. 62-9898

[0011] Patent Document 2: Japanese Patent Application Publication No. 55-145174 Summary of the Invention

[0012] The technical problem that the invention aims to solve

[0013] Figure 5This is a perspective view showing an example of a sheet metal used in a laminated iron core. In the illustrated example, sheet metal 1 is rectangular, having opposing front and back faces 20 and four sides 25 connecting the front and back faces 20. Sheet metal 1, obtained from a thin strip, is easily flexed, but when placed on a platform, the front and back faces 20 of sheet metal 1 are substantially flat, and if no plastic deformation such as bending occurs, it will take the shape shown in the illustration. The front and back faces 20 of sheet metal 1 retain the planar state of the sheet metal during its fabrication, while the sides 25 are cross-sections created by processing. Figure 6 This is a perspective view illustrating an example of a stacked iron core constructed by overlapping multiple thin plates. In the stacked iron core 5, several to several thousand thin plates 1 are stacked together, and these plates are fixed together as a whole by means of spot welding, riveting, bonding, etc.

[0014] Figure 15 This is a simplified representation of a part of the stamping apparatus used to explain the blanking process. Additionally, Figure 16 This is an enlarged perspective view showing the side surface of a sheet metal produced by a punching process. Typically, on the side surface 25 of the sheet metal 1, shear stress generated by punching creates a shear surface 135 and a fracture surface 138, and in the thickness direction of the sheet metal 1, a collapsed edge 131 and burrs 120 associated with plastic deformation are formed. In the punching process, a thin strip (not shown) is placed on a die 19 with a punching hole and pressed down, while a punch 18 is lowered from above the punching hole. Although it also depends on the thickness of the thin strip, the punch 18 passes through the punching hole of the die 19 at intervals of about a few μm to 100 μm, and the thin strip is sheared using a cutting tip located on the edge of the front end of the punch 18 and a cutting tip located on the edge of the punching hole of the die 19. On the sheet metal 1 obtained by punching from the thin strip through the shearing process, burrs 120 are formed along the outer periphery of the punch 18 in the thickness direction.

[0015] While the method disclosed in Patent Document 1 can suppress the degree of burrs generated in the thickness direction of the thin sheet, it cannot prevent the burr height from increasing over time due to changes in the wear of the die and punch. From the perspective of the stamping process mechanism, the generation of burrs in the thickness direction of the thin sheet is inherently difficult to eliminate.

[0016] Furthermore, while etching methods avoid producing the thickness-direction burrs that occur in thin sheets during stamping, they require multiple steps such as resist coating and etching, resulting in lower productivity compared to stamping and making them unsuitable for mass production of thin sheets. Laser processing and electrical discharge machining also suffer from slower processing speeds and lower productivity compared to stamping.

[0017] Figure 17This is an enlarged view of a cross-section of a laminated iron core constructed by stacking thin plates with burrs. The thin plates 1 are stacked offset in the planar direction via resin layers 200 that bond the interlayers. Burrs 120 generated on the side surfaces of the thin plates 1 protrude from the front and back surfaces 20, thus potentially causing short circuits when the plates 1 come into contact with each other during stacking. These short circuits between the plates 1 are a major cause of increased eddy current losses, hindering the reduction of losses in the laminated iron core 5. Furthermore, since the burrs 120 are generated at the edges of the thin plates 1, as the number of layers of thin plates 1 increases, the side surfaces of the laminated iron core 5 become thicker and larger than the central portion, affecting the dimensional accuracy of the laminated iron core 5. Additionally, there are cases where it is impossible to improve the duty cycle (the ratio of the volume of the thin plates to the volume of the laminated iron core 5).

[0018] Therefore, the object of the present invention is to provide a Fe-based soft magnetic amorphous alloy sheet that can easily reduce the loss of a laminated iron core, a laminated iron core and a rotary motor using the sheet, and a method for manufacturing the Fe-based soft magnetic amorphous alloy sheet.

[0019] Means for solving technical problems

[0020] According to one aspect of the present invention, a Fe-based soft magnetic amorphous alloy sheet for laminated iron cores is provided, characterized in that: the sheet has: opposing front and back sides; and side sides, the thickness of the sheet is 10 to 50 μm, the side sides have fracture surfaces that are inclined relative to the thickness direction of the sheet from the front and back sides respectively, and the side sides are V-shaped that gradually tapers towards the ends in the cross section of the sheet in the thickness direction.

[0021] According to one aspect of the invention, the fracture surface is preferably a fracture surface generated by ductile fracture.

[0022] According to one aspect of the invention, it is preferred that all sides of the thin plate are V-shaped.

[0023] According to one aspect of the invention, the fracture surface is preferably defined as the region extending at a distance L of 5 μm or more from the V-shaped end that forms the outer edge of the thin plate.

[0024] In addition, according to one aspect of the present invention, it is possible to provide a laminated iron core obtained by overlapping Fe-based soft magnetic amorphous alloy thin plates.

[0025] In addition, according to one aspect of the present invention, it is possible to provide a rotary electric motor in which a laminated core obtained by overlapping and fixing Fe-based soft magnetic amorphous alloy sheets is used in the stator or rotor.

[0026] In addition, the Fe-based soft magnetic amorphous alloy sheet of the present invention can be provided by a method for manufacturing the Fe-based soft magnetic amorphous alloy sheet, the method comprising: overlapping a thin strip of Fe-based soft magnetic amorphous alloy and a thin strip of non-metallic material with a thickness of 10 to 150 μm, and cutting the thin strip of Fe-based soft magnetic amorphous alloy and the thin strip of non-metallic material together using a rotary die cutter or a Thomson blade.

[0027] Invention Effects

[0028] The present invention provides a Fe-based soft magnetic amorphous alloy sheet that can easily reduce the loss of a laminated iron core, a laminated iron core and a rotary motor using the sheet, and a method for manufacturing the Fe-based soft magnetic amorphous alloy sheet. Attached Figure Description

[0029] Figure 1 This is a magnified perspective view of the side of a Fe-based soft magnetic amorphous alloy thin plate according to one embodiment of the present invention.

[0030] Figure 2 This is a cross-sectional view obtained by cutting a Fe-based soft magnetic amorphous alloy thin plate along the thickness direction according to one embodiment of the present invention.

[0031] Figure 3 This is a structural diagram illustrating one embodiment of a processing apparatus for Fe-based soft magnetic amorphous alloy strips.

[0032] Figure 4 It means Figure 3 A perspective view of one embodiment of the die-cutting roller used in the processing apparatus.

[0033] Figure 5 This is a perspective view showing one embodiment of the thin plate used in a laminated iron core.

[0034] Figure 6 This is a perspective view showing one embodiment of a laminated iron core constructed by overlapping multiple thin plates.

[0035] Figure 7 This is a cross-sectional view of one embodiment of a laminated iron core formed by overlapping multiple thin plates.

[0036] Figure 8 This is a perspective view showing another embodiment of a Fe-based soft magnetic amorphous alloy thin plate.

[0037] Figure 9 yes Figure 8 The image shows a partially enlarged 3D view of a Fe-based soft magnetic amorphous alloy thin plate.

[0038] Figure 10 This is a perspective view showing another embodiment of a laminated iron core constructed by overlapping multiple thin plates.

[0039] Figure 11 This is a schematic diagram illustrating one embodiment of a rotary electric motor using the laminated iron core of the present invention.

[0040] Figure 12 These are laser microscope images obtained by observing the front, back, and side views of the thin plate of Example 1.

[0041] Figure 13 These are laser microscope images obtained by observing the side view of the cross-section of the thin plate in Example 1.

[0042] Figure 14 These are laser microscope images obtained by observing the surface profile of the thin plate in Example 1.

[0043] Figure 15 It is a simplified cross-sectional view obtained from a part of the stamping device used for punching thin strips.

[0044] Figure 16 It is a magnified three-dimensional view of the side of a thin sheet produced by stamping.

[0045] Figure 17 It is a cross-sectional view of a laminated iron core made by stacking thin plates with burrs.

[0046] Explanation of reference numerals in the attached figures

[0047] 1. Fe-based soft magnetic amorphous alloy sheet, 5, 10. Stacked iron core, 6. Protrusion, 7. Circular part, 18. Punch, 19. Die, 20. Front and back of sheet, 25. Side of sheet, 30. Inclined surface of sheet, 85. Fracture surface caused by ductile fracture, 120. Burr, 131. Collapsed edge, 135. Shear surface, 138. Fracture surface, 200. Resin layer, 260. Stator winding, 280. Rotary motor, 290. Permanent magnet, 300. Reel wound with Fe-based soft magnetic amorphous alloy strip, 301. Fe-based soft magnetic amorphous alloy strip, 305. Reel wound with non-metallic strip, 306. Non-metallic strip, 350. Die-cutting roller, 351. Cutting knife, 355. Anvil roller, 360. Reel wound with processed Fe-based soft magnetic amorphous alloy strip, 370. Container for recycling processed sheet. Detailed Implementation

[0048] The embodiments of the present invention will now be described in detail, but the present invention is not limited thereto. In some or all of the figures, parts unnecessary for the description have been omitted, and some parts have been shown in an enlarged or reduced manner for ease of explanation. In this specification, the numerical range indicated by “~” refers to the range of values ​​described before and after the “~” as a lower and upper limit. In this specification, the term “process” includes not only independent processes, but also processes that can be clearly distinguished from other processes, as long as the desired purpose of the process can be achieved.

[0049] Figure 1 This is an enlarged perspective view showing the side surface of a Fe-based soft magnetic amorphous alloy thin plate according to one embodiment of the present invention. Figure 5 The same shape. The side 25 of the thin plate 1 is a machined section of the inclined surface 30 that is inclined from the front and back sides 20 respectively with respect to the thickness direction (z direction in the drawing) of the thin plate 1. Figure 2 This is a cross-sectional view obtained by cutting the thin plate 1 along its thickness direction. In the cross-section (xz plane) along the thickness direction of the thin plate 1, the side surface 25 of the thin plate 1 is a V-shape that gradually tapers towards the ends. In the inclined surface 30, the distance L from the end of the V-shape towards the front and back faces 20 is the fracture surface 85 resulting from ductile fracture. Here, ductile fracture refers to fracture associated with plastic deformation. When the fracture surface is observed using an electron microscope, traces of fine deformation can be observed, exhibiting a fracture pattern different from brittle fracture and fatigue fracture. Since the inclined surfaces are continuous from the opposing front and back faces 20, it is not necessary to differentiate and overlap the front and back faces 20 of the thin plate 1 to fabricate a laminated core, making the process easier.

[0050] Most of the inclined surface 30 is the fracture surface 85. Microscopically, the fracture surface 85 is a discontinuous surface composed of surfaces with different inclinations, but macroscopically it only needs to be a surface that moves away from the flat front and back surfaces 20 towards the edge of the sheet. The side surface 25 includes not only linearly inclined surfaces as shown in the figure when viewing the cross-section in the thickness direction of the sheet 1, but also curved inclined surfaces and undulating (wavy) morphologies. Furthermore, the shape of the inclined surface and / or the region of the fracture surface 85 extending from the end of the V-shape at a distance L may differ between inclined surfaces continuous with one of the front and back surfaces and those continuous with the other. Additionally, there are cases where the fracture surface has a vein-like structure. Vein-like structures are known to be characteristic of amorphous alloys and can also be observed in fracture surfaces produced by tension. Vein-like structures result from deformation due to localized temperature increases caused by thermal insulation and viscous fluidity.

[0051] In the sheet 1 formed by punching as described above, due to the burrs 120, the angle formed between the front and back surfaces 20 and the side surface 25 (fracture surface 138) is an acute angle and protrudes towards the front and back surfaces 20. However, in the sheet 1 of the present invention, there are no burrs protruding towards the front and back surfaces 20, and the angle formed between the front and back surfaces 20 and the side surface 25 (inclined surface 30) is an obtuse angle. Figure 7 This shows the cross-section of the laminated iron core 5, which is constructed by stacking such thin plates 1. As shown, no interference such as contact between the thin plates 1 caused by burrs occurs in the laminated iron core 5, and it is possible to produce a laminated iron core 5 in which the increase of eddy current loss caused by short circuits is suppressed. Furthermore, the V-shaped portion in the side surface 25 of the thin plate 1 may be only a portion, but it is preferable that the V-shaped portion is 50% or more, more preferably 80% or more, relative to the perimeter of the side surface.

[0052] In blanking processes, it is difficult to eliminate the generation of burrs protruding in the thickness direction at the edges of thin sheets. Therefore, the inventors of this invention have conducted various studies on processing techniques for obtaining thin sheets of a specified shape from thin strips. Among these studies, the following insight was obtained: by using a Thomson cutter or a rotary die-cutting machine to cut the thin strip, the generation of burrs protruding in the thickness direction of the thin sheet can be prevented. By utilizing a combination of a Thomson cutter and a base (support table) described later, or a combination of a die-cutting roller and an anvil roller, the thin strip is crushed by the cutter tip, causing it to plastically deform and break. This prevents the generation of burrs protruding in the thickness direction that would occur during shearing processes on the resulting thin sheet. Furthermore, the side surface 25 is composed of an inclined surface 30 having a fracture surface 85, as shown... Figure 1 The V-shape shown tapers at the front.

[0053] In laminated iron cores, a thinner plate is preferred to reduce eddy current losses. However, the thinner the plate, the more the duty cycle decreases due to surface roughness and unevenness. Therefore, the thickness of the Fe-based soft magnetic amorphous alloy sheet (strip) is preferably 10 μm or more and 50 μm or less. More preferably, it is 12 μm or more, and even more preferably 15 μm or more. Furthermore, it is more preferably 45 μm or less, and even more preferably 40 μm or less. The Fe-based soft magnetic amorphous alloy strip can appropriately use commercially available materials such as METGLAS (registered trademark) 2605SA1.

[0054] The manufacturing method of the Fe-based soft magnetic amorphous alloy thin plate of the present invention will now be described in detail with reference to the accompanying drawings. Figure 3This is a structural diagram of a strip processing device including a rotary die-cutting machine. The rotary die-cutting machine consists of a cylindrical die-cutting roll 350 and an anvil roll 355. While the die-cutting roll 350 and the anvil roll 355 are rotating, a sheet-like workpiece is inserted between them. The workpiece is obtained by overlapping a strip of Fe-based soft magnetic amorphous alloy and a non-metallic strip. The front and back sides of the Fe-based soft magnetic amorphous alloy strip 301 wound from the spool 300 are respectively overlapped with the non-metallic strip 306 wound from the spool 305. The Fe-based soft magnetic amorphous alloy strip 301 is fed to the rotary die-cutting machine while being sandwiched between the non-metallic strip 306. Figure 4 This is a perspective view of the die-cutting roller. Multiple cutting blades 351 are present on the surface of the die-cutting roller 350. The tips of the cutting blades 351 are several μm to tens of μm wide and are flat. Using the cutting blades 351, the workpiece fed to the rotary die-cutting machine is pressed against the surface of the anvil roller 355, thereby crushing and breaking the Fe-based soft magnetic amorphous alloy strip 301. The sheet 1 cut from the workpiece, along with the non-metallic end pieces cut from the workpiece, are collected in the container 370. The workpiece from the rotary die-cutting machine is wound onto the reel 360.

[0055] The non-metallic thin strip 306 functions as a cushioning material, and can be, for example, a film-like resin, Japanese paper, or Western paper with a thickness of 10–150 μm. Preferred resins include polyethylene, polyvinyl chloride, acrylic resin, polyethylene terephthalate, and polycarbonate.

[0056] Even if the die-cutting roller's cutting blade wears down, no burrs protruding in the thickness direction of the sheet will be produced, thus enabling the stable production of sheet metal with V-shaped sides. Furthermore, as the cutting blade wears down, sheet metal cutting becomes impossible, and a portion of the end easily becomes connected to the Fe-based soft magnetic amorphous alloy strip. Observing this separation state serves as an indicator of the cutting blade's wear level, allowing for blade correction, thereby simplifying the maintenance and management of the strip processing equipment. This invention is not limited to this; a cutting method using a Thomson stencil can also be used.

[0057] Thin sheets obtained by shaping Fe-based soft magnetic amorphous alloy strips can be stacked and laminated together using adhesives or the like. In the lamination process, the following method is preferred: preparing an alignment jig and pressure plates corresponding to the shape of the thin sheets; overlapping the desired number of thin sheets within the alignment jig; and laminating them together using pressure plates stacked on top of each other. In bonding Fe-based amorphous alloy thin sheets, it is preferable to form a resin layer uniformly; however, if the required bond strength can be obtained, a resin layer can also be formed locally. The resin can be applied to the Fe-based amorphous alloy thin sheets by dripping or spraying liquid resin onto the sheet, or by immersing the sheet in liquid resin. Alternatively, the resin can be applied using a coating applicator (coating device) before processing the Fe-based soft magnetic amorphous alloy thin sheets, or by immersing the strip in liquid resin, followed by a shaping process for lamination.

[0058] The resins used for bonding thin sheets are preferably epoxy resins or acrylic resins. Among these resins, resins with high heat resistance are preferred.

[0059] A thinner resin layer between the thin plates results in a higher fill factor for the laminated core, which is therefore preferable. To achieve both the desired adhesive strength and a high fill factor (80%–98%), the thickness of the resin layer between the thin plates is preferably around 1 μm to 5 μm, more preferably in the range of 1 μm to 3 μm. This prevents the formation of burrs protruding in the thickness direction at the edges of the thin plates, allowing for a thinner resin layer. Furthermore, even with a thinner resin layer, the volume increase at the edges of the laminated core can be suppressed.

[0060] Figure 8 This is a perspective view showing another embodiment of a Fe-based soft magnetic amorphous alloy sheet. The sheet 1 shown is used for a laminated core of a rotary motor and has an annular portion 7 with a plurality of protrusions 6 arranged rotationally symmetrically along its inner circumference. Figure 9 This is a partially enlarged perspective view of a thin plate. The thin plate 1 shown in the figure has a shape with multiple side surfaces 25 on the inner diameter side. Such a thin plate 1 also utilizes... Figure 5 The thin plate shown is manufactured using the same method, thus preventing burrs protruding in the thickness direction from forming at the edge of the thin plate 1, and enabling the side surface 25 of the thin plate 1 to be as shown. Figure 1 The inclined surfaces shown are inclined relative to the thickness direction of the sheet 1 from the front and back sides 20, and are V-shaped that gradually tapers towards the ends. The shape of the sheet in this invention is not particularly limited and can be of various forms.

[0061] Figure 10This is a perspective view of a laminated iron core constructed by stacking thin sheets of Fe-based soft magnetic amorphous alloy. The laminated iron core 10 shown is used as the stator of a rotating electric machine, with hundreds to thousands of thin sheets 1 stacked on top of each other. The annular portion 7 serves as the rear yoke of the stator, and the protrusions 6 become pole teeth. The resulting laminated iron core 10 can also suppress the increase in eddy current losses caused by short circuits between the thin sheets 1.

[0062] Figure 11 This is a schematic diagram illustrating an example of a rotary electric motor using the laminated iron core 10 of the present invention. (See diagram below.) Figure 11 As shown, the rotary motor 280 of the present invention has a rotor disposed with a gap on the inner diameter side of the stator (laminated core) 10. A plurality of permanent magnets 290 are arranged on the outer periphery of the rotor. The permanent magnets 290 are magnetized such that the side opposite to the stator 10 is either the N pole or the S pole, and are arranged at equal angles with adjacent permanent magnets 290 having alternating opposite polarities. Figure 11 In the configuration shown, the rotor has 8 poles, but the number of magnetic poles is not limited to this.

[0063] Stator windings 260 are provided on the pole teeth 6 of the stator 10. A three-phase alternating current based on the position of the rotor's magnetic poles is supplied to the stator windings 260, generating a rotating magnetic field in the stator. The rotary motor operates as a rotary motor by utilizing the rotor's permanent magnets 260 and the rotating magnetic field. In this invention, by using a stacked iron core made of Fe-based soft magnetic amorphous alloy thin plates with a thickness of 10-50 μm and no burrs in the thickness direction as the stator, a rotary motor capable of operating with high efficiency can be realized.

[0064] [Example]

[0065] As a thin strip of Fe-based soft magnetic amorphous alloy, Metglas (registered trademark) 2605SA1 manufactured by Hitachi Metals Corporation was prepared. The strip was elongated, with a thickness of 25 μm and 32 μm and a width of 30 mm. The Fe-based soft magnetic amorphous alloy strip was broken using a Thomson scalpel or die-cutting roller to produce... Figure 8 The sheet has the shape shown. The sheet has an outer diameter of 22 mm and an inner diameter of 10 mm.

[0066] (Example 1)

[0067] Using the aforementioned rotary die-cutting machine, a thin sheet of Fe-based soft magnetic amorphous alloy strip is formed. A 25 μm thick Fe-based soft magnetic amorphous alloy strip is sandwiched between a 13 μm thick polyethylene film as a buffer material, and the anvil roller and die-cutting roller are brought close together to allow the workpiece to pass through, thus producing a thin sheet. The cutting blade of the die-cutting roller has a blade tip with a width of 15–30 μm and is flat, with a blade tip angle of 30°.

[0068] (Example 2)

[0069] A thin plate was fabricated in the same manner as in Example 1, except that a thin strip of Fe-based soft magnetic amorphous alloy with a thickness of 32 μm was used.

[0070] (Example 3)

[0071] Thin sheets are produced by cutting a 25μm thick Fe-based soft magnetic amorphous alloy strip using a Thomson scalpel. The cutting device for mounting the Thomson scalpel includes a drive mechanism that reciprocates the Thomson scalpel up and down; and a base with a flat cutting surface for positioning the strip, enabling the sheet to break by moving the Thomson scalpel towards the cutting surface. The Fe-based soft magnetic amorphous alloy strip is sandwiched between a 100μm thick polyethylene film as a buffer material, and a pressure of 150N is applied using the Thomson scalpel to break the strip, thus producing a thin sheet. The Thomson scalpel also has a 20μm wide, flat tip with a 45° tip angle.

[0072] The thin plates obtained in Examples 1 to 3 were observed from the front and back sides using a VK-X1000 laser microscope manufactured by Keyence. Figure 12 The images show laser microscope photographs obtained by observing the front and back sides of the thin plate of Example 1. Additionally, each thin plate was cut, and the cut surfaces embedded in the resin were exposed and observed by grinding. Figure 13 The images shown are laser microscope photographs obtained from the side views of the cross-section of the thin plate of Example 1. From the photographs, it can be seen that the side views all have continuous inclined surfaces from the front and back sides. The entire inclined surface is composed of fracture surfaces resulting from ductile fracture, and the cross-sectional shape is a gradually tapering V-shape. Furthermore, no burrs protruding in the thickness direction that would occur during shearing were observed. By observing the front and back sides of the thin plate, the distance L measured from the end of the V-shape on the side of the fracture surface, and the minimum and maximum distances are shown as the fracture surface distance L in Table 1.

[0073] [Table 1]

[0074]

[0075] The Fe-based soft magnetic amorphous alloy sheet of the present invention has a fracture surface on its side in a region of approximately 10 to 100 μm, and its cross-section tapers towards the ends. For the sheet of Example 1, a 270 μm × 202 μm region including the front, back, and inclined surfaces was used as the evaluation area and observed at 50x magnification using a Keyence VK-X1000 laser microscope. Figure 14The surface profile of the thin plate is shown. No burrs protruding in the thickness direction were found at the corner formed by the front and back surfaces 20 and the inclined surface 30. Therefore, it can be seen that in the laminated iron core obtained by stacking the thin plates of the present invention, it is difficult for interlayer electrical short circuits to occur, and the loss of the laminated iron core can be easily reduced.

Claims

1. An Fe-based soft magnetic amorphous alloy sheet for a laminated core, characterized by: the sheet having opposite front and back surfaces; and side surfaces, the sheet having a thickness of 10 to 50 μm, the side surfaces having fracture surfaces resulting from ductile fracture that are inclined with respect to a thickness direction of the sheet from the front and back surface sides, respectively, the side surfaces being V-shaped in cross section in the thickness direction of the sheet, tapering gradually toward the end portions, the fracture surfaces being fracture surfaces formed by pressing the ribbon to plastically deform and break.

2. The Fe-based soft magnetic amorphous alloy sheet according to claim 1, characterized by: all of the side surfaces of the sheet being V-shaped.

3. The Fe-based soft magnetic amorphous alloy sheet according to claim 1 or 2, characterized by: a region of a range of 5 μm or more inward from an end portion of the V-shaped side surface that is an outer edge of the sheet being the fracture surface.

4. A laminated core, characterized by: being formed by overlapping the Fe-based soft magnetic amorphous alloy sheet according to any one of claims 1 to 3.

5. A rotary electric machine, characterized by: using the laminated core according to claim 4 in a stator or a rotor. including: a step of overlapping a front and back surface of a ribbon of an Fe-based soft magnetic amorphous alloy having a thickness of 10 to 50 μm with a ribbon of a non-metallic material having a thickness of 10 to 150 μm; and a step of cutting the ribbon of the Fe-based soft magnetic amorphous alloy together with the ribbon of the non-metallic material using a rotary die cutter or a thomson cutter, thereby obtaining a sheet having opposite front and back surfaces, and side surfaces having fracture surfaces that are inclined with respect to a thickness direction of the sheet from the front and back surface sides, respectively, the fracture surfaces being V-shaped in cross section in the thickness direction of the sheet, tapering gradually toward the end portions. ​ ​ ​ ​ 6. A method for manufacturing a Fe-based soft magnetic amorphous alloy thin plate, characterized in that, ​ ​ ​ ​

Images