Method for manufacturing a laminated iron core, a laminated iron core, and a rotating electric machine using a laminated iron core

Abstract

To provide a laminated core manufacturing method, a laminated core, and a rotating electric machine that increase productivity, significantly reduce wear and tear on a mold in a punching amorphous metal sheet, and achieve longer life.SOLUTION: A laminated core is manufactured by punching out an amorphous metal sheet and process it into the specified shape by using a die, and assembling the shaped amorphous metal thin plate by a predetermined amount. In the shape processing according to the present invention, a laminated amorphous metal thin plate is formed by laminating a plurality of amorphous metal thin plates, the laminated amorphous metal thin plate is punched using the die with the surface having less surface disposed on the processing side to form a unit laminate. Then, a required number of unit laminates are laminated to assemble the laminated core.SELECTED DRAWING: Figure 9

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a laminated core using an amorphous metal thin plate, a laminated core, and a rotating electric machine using the laminated core.

Background Art

[0002] In order to suppress global warming, the development of technologies for reducing carbon dioxide (CO2) emissions is required. For this reason, great expectations are placed on improving the efficiency of motors. Approximately 70% of the electric power used in industrial fields and approximately 40% of the electric power used in households are consumed by motors. It is said that by simply improving the efficiency of each motor by a few percent, an energy-saving effect equivalent to a power plant of several hundred thousand kW can be expected, contributing to the reduction of several million tons of CO2 per year. On the other hand, in recent years, for the purpose of reducing CO2 emissions as well, the spread of electric vehicles has been remarkable, and in order to extend the driving range per charge, the demand for improving the efficiency of drive motors has been increasing.

[0003] Conventional stator cores using electromagnetic steel sheets are generally formed by punching an electromagnetic steel sheet with a thickness of, for example, 0.15 mm to 0.5 mm into a ring-shaped cross-sectional shape with grooves (slots) using a mold, and laminating and fixing the punched members using caulking, welding, adhesion, etc. to form a cylindrical stator core.

[0004] Here, amorphous metal has attracted attention as a material that meets the strong social demand for improving the efficiency of motors in recent years. Compared with conventional electromagnetic steel sheets, the iron loss of amorphous metal is about 1 / 10, which is significantly smaller. Therefore, if amorphous metal can be used as a material for the cores of stators and rotors for motors, the efficiency can be significantly improved (for example, +5 to 6%) compared to motors using conventional electromagnetic steel sheets for cores.

[0005] Currently, the dominant method for manufacturing amorphous metal sheets is the "roll method," in which molten iron-based or cobalt-based metal is continuously supplied onto a rotating cooling roll and rapidly cooled and solidified on the roll. By adjusting the rotation speed of the cooling roll, the molten alloy is cooled at a predetermined speed to produce a thin, strip-shaped amorphous metal sheet. This roll method can only produce foil-like amorphous metal sheets with a thickness of about 25 μm. On the other hand, amorphous metal sheets (amorphous metal foils) have very high hardness (Hv = 900-1100), which is extremely high compared to ordinary electrical steel sheets (Hv = 200-300). For this reason, when processing amorphous metal sheets into stator shapes, molds made of cemented carbide are used. However, if an amorphous metal sheet with a thickness of about 25 μm is to be used as the material for a stator core, the number of shots required to punch out the material for one stator core becomes extremely large. For example, motor cores can be several meters tall, and using 0.35-0.5mm thick electrical steel sheets requires thousands to tens of thousands of punching shots per motor. In contrast, using amorphous metal sheets as the material for motor cores increases the number of shots required to punch out the thickness of one core to 14 to 20 times that of electrical steel sheets. Furthermore, the extreme hardness of amorphous metal sheets increases the load on the die (punch), resulting in an extremely short die life. Note that amorphous metal sheets are sometimes referred to as amorphous metal sheets below due to their extremely thin thickness.

[0006] One technology for solving such technical problems is the one described in Japanese Patent Publication No. 56-36336 (Patent Document 1). Patent Document 1 discloses a manufacturing method for producing a laminated core made of amorphous metal sheets by first laminating amorphous metal sheets with an electrical insulating layer in between, and then mechanically punching out a predetermined core shape. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 56-36336 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] According to the technology described in Patent Document 1 above, it is stated that punching out amorphous metal sheets in a stacked state significantly reduces the wear and tear on the molds used compared to punching out each sheet individually.

[0009] However, the technology described in Patent Document 1 does not include any description of further significantly reducing the wear of the die used for punching by taking into account the properties of the amorphous metal sheet to be punched.

[0010] Incidentally, when amorphous metal sheets are manufactured using the roll method as described above, there is a significant difference in the properties of the two surfaces of the metal foil, specifically in surface roughness. The inventor focused on this difference in surface roughness of amorphous metal sheets and conducted numerous experiments and studies to investigate how this difference affects actual die-cutting. As a result, the inventor discovered that die-cutting from the side with less surface roughness places far less strain on the die than die-cutting from the side with more surface roughness. Therefore, the inventor decided to utilize this new finding to tackle the challenge of increasing productivity and significantly reducing die wear compared to conventional methods, and to solve this technical problem.

[0011] The present invention aims to provide a method for manufacturing laminated iron cores that increases productivity and significantly reduces die wear in the punching process of amorphous metal sheets, thereby extending the lifespan of the die; a laminated iron core manufactured by this method; and a rotating electric machine using the same. [Means for solving the problem]

[0012] The present invention provides, as an example, a method for manufacturing a laminated iron core, which involves punching an amorphous metal sheet with a die to process it into a predetermined shape, and then using a predetermined amount of the amorphous metal sheet after the processing to manufacture a laminated iron core. The method for manufacturing a laminated iron core includes, in the processing step, a step of stacking multiple amorphous metal sheets to form a laminated amorphous metal sheet, and a step of placing the side of the laminated amorphous metal sheet with less surface roughness on the processing side before punching it with the die.

[0013] Another example of the present invention is a laminated iron core for use in electrical equipment, wherein the laminated iron core is formed by using a predetermined amount of unit laminates, which are obtained by laminating multiple amorphous metal thin sheets and punching them out so that sagging occurs on the surface with low surface roughness.

[0014] Furthermore, to give another example of the present invention, a rotating electric machine using a laminated core, wherein the laminated core is formed by using the required number of unit laminates, which are made of multiple amorphous metal sheets punched out so that sagging occurs on the surface with low surface roughness. [Effects of the Invention]

[0015] According to the present invention, productivity can be increased and the lifespan of the dies used for punching amorphous metal sheets can be extended. [Brief explanation of the drawing]

[0016] [Figure 1] This figure shows the cross-sectional shape of a strip-shaped amorphous metal sheet. [Figure 2] This diagram illustrates the measurement locations for the edge shape of the cylindrical punch during the demonstration experiment. [Figure 3A] This figure shows the data obtained when an amorphous metal sheet is punched out from the side with the greater surface roughness. [Figure 3B] This figure shows the data obtained when an amorphous metal sheet is punched out from the side with the lower surface roughness. [Figure 4]It is a diagram showing a finite element method model of the punching process of an amorphous metal thin plate. [Figure 5] It is a diagram showing the relationship between the number of laminated sheets constituting a unit laminate and the frictional work per punching. [Figure 6] It is a diagram showing the relationship between the number of laminated sheets and the maximum principal stress of tension on the punch surface. [Figure 7A] It is an explanatory diagram of the reason why the maximum principal stress of tension decreases with an increase in the number of laminated sheets, and is a diagram showing the case of one laminated sheet. [Figure 7B] It is an explanatory diagram of the reason why the maximum principal stress of tension decreases with an increase in the number of laminated sheets, and is a diagram showing the case of four laminated sheets. [Figure 8] It is a diagram showing the relationship between the number of laminated sheets of a unit laminate and the equivalent stress of compression on the punch surface. [Figure 9] It is a diagram showing the laminated core manufacturing system in Example 1 of the present invention. [Figure 10] It is a diagram for explaining the formation of the laminated amorphous metal thin plate in Example 1. [Figure 11] It is a diagram showing the stator in Example 2 of the present invention. [Figure 12] It is a diagram showing the rotating electric machine in Example 3 of the present invention. [Figure 13] It is a diagram showing the stator of the rotating electric machine in Example 3.

Embodiments for Carrying Out the Invention

[0017] The present invention will be described in detail below with reference to specific embodiments. It should be noted that the present invention is not limited to the embodiments (examples) described below, and it will be easily understood by those skilled in the art that its configuration can be modified without departing from the technical idea or spirit of the invention. Furthermore, in the following description, the same reference numerals (numbers) are generally used for identical devices and parts with similar operation or function, and redundant explanations may be omitted. Also, the positions, sizes, shapes, and ranges of each component shown in the drawings are simplified for the sake of easier understanding of the present invention and do not represent the actual positions, sizes, shapes, and ranges of each component.

[0018] [Technical considerations regarding negative test results] First, before describing specific embodiments of the present invention, we will explain the technical considerations or principles of the invention that form the basis of the embodiments.

[0019] Amorphous metal sheets (amorphous metal foils) manufactured by the roll process are typically used for the cores of rotating electric machines and transformers. In the roll process, molten metal is supplied to the surface of a cooling roll that rotates at a constant speed, and the molten metal is rapidly cooled and solidified on the cooling roll to produce long, strip-shaped amorphous metal sheets (strip amorphous metal sheets) with a thickness of approximately 25 μm. Figure 1 shows a cross-section of a strip amorphous metal sheet manufactured in this way. Because the strip amorphous metal sheet 1 is manufactured by rapidly cooling and solidifying the molten metal on the surface of the cooling roll, the surface roughness of the non-roll contact surface is large, at 2.5 μm or more (for a material thickness of 25 μm), while the roll contact surface is a smooth surface with less surface roughness. That is, as shown in Figure 1, the strip amorphous metal sheet 1 has a non-roll contact side S1 and a roll contact side S2. Note that Figure 1 shows a schematic representation of the cross-sectional shape for illustrative purposes and does not depict the precise cross-sectional shape based on actual measurement data. As can be seen from Figure 1, the surface S2 that is in direct contact with the cooling roll is a smooth surface with low surface roughness, while the surface S1 that is not in contact with the cooling roll has a rougher surface roughness.

[0020] Through repeated experiments and studies to investigate how the difference in surface roughness on these two sides affects the punching process, it was found that the load on the die (punch) differs significantly depending on whether the side with the higher surface roughness, S1, is placed on the punch side (processing side) or, conversely, the side with the lower surface roughness, S2, is placed on the punch side (processing side).

[0021] To demonstrate this, an amorphous metal sheet with a thickness of 25 μm was used, made of SKD11 material (yield strength: 1570 N / mm²). 2 Tensile strength: 1810 N / mm 2 Compression strength 2700 N / mm 2 The material was punched using a circular cross-section punch, and the shape of the punch tip edge in its initial state and the shape of the punch tip edge after punching 1800 pieces were measured using a 3D measuring machine, and the results were compared. Figure 2 is a diagram illustrating the measurement position of the punch edge shape in this experiment. In Figure 2, the shape viewed from the bottom of the punch 12 is shown as 12A, and the shape viewed from the side of the punch is shown as 12B. The measurement position of the punch 12 edge shape is the part indicated by the circle 12C in the figure.

[0022] The results of this demonstration experiment are shown in Figures 3A and 3B. Figure 3A shows an example of data when an amorphous metal sheet is punched out with a cylindrical punch, with surface S1 (the side with high surface roughness) as the processing side (punch side). Figure 3B shows an example of data when an amorphous metal sheet is punched out with a punch, with surface S2 (the side with low surface roughness) as the processing side. In Figures 3A and 3B, the dashed line A0 shows the initial state, and the solid line A1 shows the state after 1800 punches.

[0023] As can be seen by comparing Figure 3A and Figure 3B, when punching is performed with the side with the lower surface roughness S2 on the punch side (processing side) (Figure 3B), the punch undergoes greater plastic deformation toward the outer circumference than when punching is performed with the side with the higher surface roughness S1 on the punch side (Figure 3A). This is likely because the higher surface roughness of the amorphous metal foil results in greater friction at the contact surface with the punch, causing the punch to plastically deform as it is dragged by the amorphous metal foil. On the other hand, in the case of Figure 3B, where punching is performed from the side with the lower surface roughness, wear is observed at the edge of the punch tip, but no plastic deformation toward the outer circumference is observed. This is likely because the lower surface roughness of the amorphous metal foil results in less friction at the contact surface with the punch, preventing the punch from deforming as it is dragged by the amorphous metal foil.

[0024] Thus, it can be seen that when punching the same material the same number of times, the load on the punch is reduced when the side with the smaller surface roughness, S2, is positioned on the punch side.

[0025] To efficiently increase the productivity of punching amorphous metal sheets, it is recommended to stack (laminated) multiple amorphous metal sheets before punching. In this case, by laminating a certain number of amorphous metal foils (amorphous metal sheets), the friction work (W / mm²) performed by the punch during punching of each amorphous metal foil is reduced. 2 The number of pieces per sheet decreases, and the wear on the outer circumference of the punch is reduced. In the embodiments of the present invention, the punching process is performed based on this idea.

[0026] For this study, we first created a finite element method model of punching amorphous metal sheets, as shown in Figure 4 (a model in which a punch 12 and die 13 punch out a laminate 11 of three amorphous metal sheets 9), and performed an analysis. In the model, the thickness of the strip-shaped amorphous metal sheet 1 is assumed to be 25 μm.

[0027] Figure 5 shows the results of calculating the friction work per amorphous metal foil sheet using a model when punching is performed with varying numbers of laminated amorphous metal sheets. It can be seen that when the number of laminated sheets exceeds three, the friction work per amorphous metal foil sheet decreases as the number of laminated sheets increases. However, while increasing the number of laminated sheets can reduce the number of punches, the load on the die during each punch increases. Therefore, it is important to appropriately select the number of laminated sheets in the unit laminate. Accordingly, in the improved embodiment of the present invention, this number of laminated sheets is optimized to reduce die wear and minimize the risk of die breakage.

[0028] To this end, the maximum principal tensile stress generated on the punch surface was calculated using the finite element method model described above, when the number of unit laminates was varied. The results are shown in Figure 6. The maximum principal tensile stress occurs on the bottom surface of the punch (the surface facing the amorphous metal foil). When the number of unit laminates is two or more, the tensile strength of the ultrafine particle alloy, which is the strongest material for the punch, falls below 1900 MPa. When the number of laminates is three or more, it saturates and becomes minimum at around 1000 MPa. Therefore, by increasing the number of unit laminates to three or more, the maximum principal tensile stress, i.e., the risk of chipping occurring on the bottom surface of the punch, can be minimized.

[0029] The reason why the maximum principal tensile stress decreases when the number of unit laminates is increased to three or more is thought to be as follows: Increasing the number of unit laminates from one to, for example, four reduces the amount of deflection δ of the amorphous metal sheet 9 during punching. Figure 7A shows the case when there is one amorphous metal foil, and Figure 7B shows the case when four amorphous metal foils are laminated. Comparing the amount of deflection δ in Figure 7A with the amount of deflection δ in Figure 7B, the amount of deflection δ in Figure 7B is smaller. As a result, the amorphous metal sheet 9 and the bottom surface of the punch 12 become closer to horizontal, and the component force in the same direction becomes smaller. After that, the amount of deflection of the amorphous metal foil becomes almost constant, and the maximum principal tensile stress converges to the minimum.

[0030] On the other hand, Figure 8 shows the analysis results of the equivalent stress generated on the punch surface when the number of unit laminates is changed. The equivalent stress is generated as compressive stress on the bottom surface of the punch (the surface facing the amorphous metal foil) and increases with increasing number of laminates. Here, when using the highest strength ultrafine particle alloy as the punch material, in order to prevent fracture due to compression, the equivalent stress must be less than or equal to the compressive strength of the ultrafine particle alloy, which is 6500 MPa. As shown in Figure 8, in order to satisfy this condition, the number of unit laminates must be 5 or less.

[0031] These findings indicate that the number of layers in a unit laminate that minimizes the risk of punch breakage (chipping) and prevents compression-induced failure should be between 3 and 5.

[0032] The following describes specific embodiments of the present invention based on the "Technical Considerations Regarding the Invention" described above.

[0033] [Example 1] First, let's describe Embodiment 1 of the present invention. Embodiment 1 is a laminated core manufacturing system for producing laminated cores. Figure 9 shows the main components of Embodiment 1. Specifically, the manufacturing of laminated cores involves two steps: punching out amorphous metal sheets using a die to process them into a predetermined shape, and manufacturing the laminated core using a predetermined amount (the number of sheets required for the core) of the processed laminated amorphous metal sheets. Figure 9 shows the system for the step of punching out amorphous metal sheets to process them into a predetermined shape.

[0034] In Figure 9, 1A to 1C are amorphous metal sheet coils (hereinafter simply referred to as coils) made by winding amorphous metal sheets. The amorphous metal sheets (coil material) wound on coils 1A to 1C are fed out as long strips by conveyor rolls 3A to 3C. These fed-out amorphous metal sheets 2A to 2C are supplied to the lamination bonding section 20. The arrows in the figure indicate the direction of movement (conveying direction) of the material (amorphous metal thin film).

[0035] The laminated adhesive section 20 is formed by applying adhesive to multiple amorphous metal sheets and then laminating and bonding them together. A heat-resistant insulating material is used as the adhesive. These laminated amorphous metal sheets will be referred to below as "laminated amorphous metal sheets." As mentioned above, it is preferable to laminate the amorphous metal sheets 21 to a number between 3 and 5 sheets, as this reduces the number of punching shots, thereby increasing productivity, as well as reducing die wear and lowering the risk of die damage. In this figure, an example of laminating three amorphous metal sheets is shown. The long, strip-shaped laminated amorphous metal sheets 21 are transported to the press machine 30.

[0036] Figure 10 shows the state of amorphous metal sheets. Figure 10(a) shows the cross-sectional shape of amorphous metal sheets 2A to 2C that have been fed out (wound) by the conveyor rolls 3A to 3C. Figure 10(b) shows the cross-sectional shape of the laminated amorphous metal sheet 21 laminated by the lamination bonding section 20. As is clear from Figure 10, when laminating three amorphous metal sheets, they are stacked so that the surface roughness is the same on the top and bottom. That is, if the side S2 with the smaller surface roughness of the first amorphous metal sheet is placed on top, the other amorphous metal sheets to be laminated are also stacked with the side S2 with the smaller surface roughness on top. When punching, the laminated amorphous metal sheet 21 stacked in this manner is punched out with a die (punch) of the press machine 30.

[0037] In the embodiment shown in Figure 9, when the long strip-shaped amorphous metal sheets are fed from the coils 1A to 1C, they are arranged so that the surface roughness of the amorphous metal sheets 2A to 2C is the same and supplied to the lamination bonding section 20. This eliminates the need to align the surfaces when bonding and laminating in the lamination bonding section 20. In other words, the surface side (top surface) of the amorphous metal sheets wound as coils 1A to 1C is made to have the same small surface roughness S2. Therefore, in the lamination bonding section 20, adhesive can be applied to the three amorphous metal sheets 2A to 2C and then laminated and bonded as is. The top surface of the laminated amorphous metal sheet 21 has a small surface roughness S2, and the long strip-shaped laminated amorphous metal sheet 21 is then transported directly to the press machine 30. The press machine 30 can then punch out the transported laminated amorphous metal sheet 21.

[0038] The press machine 30 punches out a laminated amorphous metal sheet 21, which is made up of multiple layers (three layers in this example), into a predetermined shape. The press machine 30 has an upper die (punch) mounted on a slide that can move up and down. The slide with the upper die mounted on it moves up and down along the slide guide by a slide drive mechanism (crank mechanism, motor that drives the crank mechanism, etc.). This causes the punch to move up and down, allowing it to punch out the laminated amorphous metal foil 21 that has been transported into the press machine. Note that the press structure and explanation of the slide, slide drive mechanism, slide guide, etc. are omitted in this figure. Also, the detailed structure and operation of the upper die (punch) and lower die (die) that constitute the die are omitted. Here, the punching process generally involves multiple punching operations. Therefore, it is preferable to use a press machine that is suitable for efficiently performing multiple punching operations. As the press machine 30 used in this embodiment, a press machine suitable for progressive die processing, such as a transfer press machine, is used. Alternatively, a tandem press machine can be used, in which multiple press machines are arranged in the processing and transport direction.

[0039] The molds 31 and 32 of the press machine 30 consist of an upper mold (punch) and a lower mold (die), with the upper mold being mounted on a slide. As the slide descends, the punch of the upper mold punches out the material into a predetermined shape. Although this press machine 30 is shown with two molds 31 and 32, three or more molds may be provided as needed depending on the processing requirements.

[0040] The laminated amorphous metal sheet, punched out by the press machine 30 and processed into a predetermined shape, is then transported outside the press machine 30 by a transport device (not shown). This punched laminated amorphous metal sheet is used as a unit laminate in the assembly process of the laminated core. Therefore, the punched laminated amorphous metal sheet is referred to here as a "unit laminate".

[0041] In this manner, the punched unit laminate 40 develops burrs at the edges of the surface S2 with less surface roughness, and burrs on the opposite side (the side with greater surface roughness). Specifically, when punching from the surface S2 with less surface roughness, the tip of the punch presses against the upper surface S2 of the material, causing the material to be pushed in and initially resulting in burrs with a rounded edge. Further lowering the punch makes it unable to withstand the bending, causing the punch to penetrate the material and cut it. When the punch is pushed all the way through, the material undergoes plastic deformation, generating protruding burrs. These burrs are generally removed before the assembly process for reasons such as the risk of injury due to their sharpness and the risk of reduced dimensional accuracy during assembly, which can negatively impact product performance.

[0042] Next, the unit laminates 40 formed as unit laminates after shaping are used in the assembly process of the laminated core to manufacture the laminated core. In this assembly process, a predetermined amount (the number of units required for the core) of unit laminates 40 are stacked and fixed together to manufacture the laminated core. A detailed explanation of the assembly process is omitted.

[0043] By using such a manufacturing system, laminated cores used in electrical equipment, such as transformer cores and stator cores for rotating electric machines, can be produced efficiently.

[0044] As described above, the laminated iron core manufacturing system shown in Example 1 of the present invention reduces the wear and tear on the die used for punching with a press machine, thereby extending its lifespan and improving productivity. Furthermore, since the number of laminated amorphous metal sheets formed before punching is set to a number that does not pose a risk of die damage, it is possible to realize an optimal method for manufacturing laminated iron cores with low die wear, low risk of die damage, and high productivity.

[0045] [Example 2] Next, Example 2 of the present invention will be described with reference to Figure 11. Example 2 shows a stator of a rotating electric machine manufactured using a unit laminate 40 punched out by the method described in Example 1. In this example, an example is shown in which a unit laminate 40 is made by stacking four sheets of laminated amorphous metal thin sheet 21 and then punching them out. As mentioned above, it is preferable that the number of stacked sheets be any number from three to five.

[0046] In Figure 11, the stator 50 is completed by winding coils (not shown) around slots 52 in the laminated core 51. The laminated core 51 is assembled by stacking the required number of unit laminates 40, which are punched out into the shape of a stator, and bonding them together, as shown in a magnified view on the right side of Figure 11. Since the outer edges of these unit laminates 40 are punched out from the side with the lower surface roughness, a sag 41 is formed on the side with the lower surface roughness (the upper side in the figure).

[0047] According to Embodiment 2 of the present invention described above, since the stator is manufactured using a unit laminate 40 obtained by punching out a laminated amorphous metal sheet from the side with the smallest surface roughness into a shape for a stator, it is possible to manufacture an optimal stator with low mold wear, low risk of mold damage, and high productivity.

[0048] In Example 2, the stator of a rotating electric machine was described, but it is also possible to manufacture a rotor. Furthermore, the same method as in Example 2 can be used to manufacture an iron core for a transformer. In this case, naturally, the shape of the unit laminate 40 punched out by the press machine will be the shape for the laminated iron core of a transformer. The laminated iron core of a transformer can be manufactured by stacking and bonding the required amount of unit laminate 40.

[0049] [Example 3] Next, Embodiment 3 of the present invention will be described with reference to Figures 12 and 13. Embodiment 3 is a rotating electric machine (motor) manufactured using the laminated iron core 51 described in Embodiment 2. Figure 12 shows the schematic configuration of the entire rotating electric machine, and Figure 13 shows the stator portion.

[0050] In Figures 12 and 13, the motor 100 has a rotor 60 mounted around a rotating shaft 70 and a stator 50 mounted on the outer circumference of the rotor. Power is supplied from the electric wire 80, causing the rotor 60 to rotate due to the electromagnetic action between the stator and the rotor. The stator 50 is the same stator 50 manufactured in the above-described embodiment 2. As shown in Figure 13, the stator 50 is completed by winding coils 53 around slots 52 of a laminated iron core 51 formed by stacking unit laminates 40.

[0051] According to Embodiment 3 of the present invention described above, since the stator is manufactured using a unit laminate 40 punched out from a laminated amorphous metal sheet punched from the side with the smallest surface roughness, the mold wear is reduced, the risk of mold damage is reduced, and a rotating electric machine can be manufactured using a highly productive stator. [Explanation of Symbols]

[0052] 1…Strip-shaped amorphous metal sheet, 9…Amorphous metal sheet, 12…Punch, 13…Die, 1A~1C…Coil, 2A~2C…Amorphous metal sheet, 3A~3C…Conveyor roll, 20…Laminated bonding section, 21…Laminated amorphous metal sheet, 30…Press machine, 31,32…Mold, 40…Unit laminate, 41…Sagging, 50…Stator, 51…Laminated iron core, 52…Slot, 53…Coil, 60…Rotor, 70…Rotating shaft, 80…Electric wire, 100…Motor

Claims

1. A method for manufacturing a laminated iron core, comprising punching an amorphous metal sheet into a predetermined shape using a die, and then using a predetermined amount of the amorphous metal sheet after shaping to manufacture the laminated iron core, A method for manufacturing a laminated iron core, comprising the steps of: stacking multiple amorphous metal sheets to form a laminated amorphous metal sheet in the shaping process; and arranging the side of the laminated amorphous metal sheet with less surface roughness towards the processing side, and then punching it out with the die.

2. In the method for manufacturing a laminated iron core described in claim 1, A method for manufacturing a laminated iron core, characterized in that the number of laminated amorphous metal sheets is any number from 3 to 5.

3. In the method for manufacturing a laminated iron core described in claim 1, The method for manufacturing a laminated iron core, characterized in that the amorphous metal sheet is a long strip-shaped material.

4. A method for manufacturing a laminated iron core according to claim 1, characterized in that the laminated iron core is an iron core for the stator of a rotating electric machine.

5. A laminated iron core used in electrical equipment, The laminated core is formed by using a predetermined amount of unit laminates, which are created by laminating multiple amorphous metal thin sheets and punching them out so that sagging occurs on the side with the smallest surface roughness.

6. In the laminated iron core described in claim 5, The laminated iron core is characterized in that the number of layers of the aforementioned unit laminate is any number from 3 to 5.

7. In the laminated iron core described in claim 5, The laminated core is characterized in that it is a core used in rotating electric machines.

8. In the laminated iron core described in claim 5, The laminated core is characterized in that it is a core used in transformers.

9. A rotating electric machine using a laminated iron core, The aforementioned laminated core is a rotating electric machine formed by using the required number of unit laminates, which are made of multiple amorphous metal sheets punched out so that sagging occurs on the surface with low surface roughness.

10. In the rotating electric machine described in claim 9, A rotating electric machine characterized in that the number of stacked units of the aforementioned laminate is any number between 3 and 5.

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