Method for producing laminated core, production device of laminated core, laminated core, and rotating electric machine

Abstract

The present invention comprises bringing heating units (212a to 212l, 222a to 222l) into contact with regions to be heated (11a to 11l) of outermost electromagnetic steel sheets (10a, 10b) of an electromagnetic steel sheet group (100) to pressurize and heat the regions to be heated (11a to 11l) at once.

Description

Laminated core manufacturing method, laminated core manufacturing device, laminated core, and rotating electric machine

[0001] The present invention relates to a laminated core manufacturing method, a laminated core manufacturing apparatus, a laminated core, and a rotating electric machine. This application claims priority to Japanese Patent Application No. 2022-132477, filed on August 23, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] Laminated cores are used as cores (iron cores) in motors, transformers, inductors, etc. Laminated cores are made by laminating soft magnetic plates such as electromagnetic steel plates. In a laminated core, the multiple laminated soft magnetic plates must be fixed together. One method for fixing the soft magnetic plates is to glue them together.

[0003] Patent Documents 1 and 2 describe techniques for bonding soft magnetic plates together. Patent Document 1 describes the following: First, multiple electromagnetic steel sheets are stacked. A coating that exhibits adhesive properties when heated is formed on the surfaces of the multiple electromagnetic steel sheets. Immediately before stacking the multiple electromagnetic steel sheets, the surfaces of the two electromagnetic steel sheets to be bonded are heated separately using local heating means. One of the two electromagnetic steel sheets heated in this way is placed on the other of the two electromagnetic steel sheets, and then pressure is applied using a press. Heating the electromagnetic steel sheets causes the adhesive properties of the coating to be exhibited, so the surfaces of the two electromagnetic steel sheets are bonded to each other.

[0004] Patent Document 2 also describes bonding multiple electromagnetic steel sheets, each having a coating on its surface that exhibits adhesive properties when heated. In the technology described in Patent Document 2, pressure and heat are applied to the electromagnetic steel sheets when they are stacked. This partially bonds the sheet surfaces of two electromagnetic steel sheets that are adjacent in the stacking direction.

[0005] Japanese Patent No. 3745490 Japanese Patent Laid-Open No. 2002-151335

[0006] However, in the technique described in Patent Document 1, the means for heating the electromagnetic steel sheets and the means for applying pressure to the electromagnetic steel sheets are configured as separate means, which makes it difficult to bond the electromagnetic steel sheets efficiently.

[0007] Furthermore, in the technology described in Patent Document 2, the electromagnetic steel sheets are bonded when they are stacked. Therefore, the number of electromagnetic steel sheets bonded at one time is limited to the number of electromagnetic steel sheets stacked at one time. Generally, electromagnetic steel sheets are stacked one by one. For this reason, it is necessary to repeatedly bond a new electromagnetic steel sheet to the topmost electromagnetic steel sheet of the multiple electromagnetic steel sheets (laminated core in the middle of being manufactured) that have already been stacked (bonded). Therefore, bonding of the electromagnetic steel sheets cannot be performed efficiently.

[0008] The present invention has been made in view of the above problems, and has as its object to enable efficient bonding of soft magnetic plates together when manufacturing a laminated core.

[0009] The method for manufacturing a laminated core of the present invention is a method for manufacturing a laminated core using a plurality of soft magnetic plates having an insulating coating formed on the entire surface of the plate that exhibits adhesive properties when heated, and includes a lamination process for stacking the soft magnetic plates, and a bonding process for bonding the plurality of soft magnetic plates stacked in the lamination process by allowing the insulating coating to exhibit the adhesive properties.In the bonding process, a heating section is brought into contact with a partial area of ​​the plate surface of the outermost soft magnetic plate, thereby simultaneously pressurizing and heating the area, and the outermost soft magnetic plate is a soft magnetic plate located at one or both ends in the stacking direction among the plurality of soft magnetic plates stacked in the lamination process.

[0010] The laminated core manufacturing apparatus of the present invention is an apparatus for manufacturing laminated cores using a plurality of soft magnetic plates having an insulating coating formed on the entire surface thereof, the insulating coating exhibiting adhesive properties when heated, and includes a heating unit that heats the soft magnetic plates to exhibit the adhesive properties, a pressure treatment means that brings the heating unit into contact with the outermost soft magnetic plate and performs a process to pressurize the soft magnetic plate, and a heat treatment means that performs a process to heat the soft magnetic plate using the heating unit, wherein the outermost soft magnetic plate is a soft magnetic plate located at one or both ends in the stacking direction of the plurality of stacked soft magnetic plates, and the pressure treatment means brings the heating unit into contact with a partial region of the plate surface of the outermost soft magnetic plate, and the heat treatment means heats the soft magnetic plate using the heating unit, thereby simultaneously pressurizing and heating the region.

[0011] A first example of a laminated core of the present invention is a laminated core constructed by stacking multiple soft magnetic plates, each having an insulating coating formed over the entire surface of the plate that exhibits adhesive properties when heated, wherein adjacent soft magnetic plates in the stacking direction are bonded to each other in a partial area of ​​the plate surface of the soft magnetic plate, and the number of areas on one plate surface of the soft magnetic plate that are bonded to the plate surface of an adjacent soft magnetic plate in the stacking direction is 0.3 × Nt or more and 6.0 × Nt or less, and the laminated core is a stator core or a rotor core, and when the laminated core is a stator core, Nt is the number of teeth of the stator core, and when the laminated core is a rotor core, Nt is the number of teeth of the stator core that is paired with the rotor core. A second example of the laminated core of the present invention is a laminated core having multiple soft magnetic plates each having an insulating coating formed on the entire surface thereof that exhibits adhesive properties when heated, the laminated core being manufactured by a process including: a lamination process for stacking the multiple soft magnetic plates; and a bonding process for bonding the multiple soft magnetic plates stacked in the lamination process by causing the insulating coating to exhibit adhesive properties, wherein in the bonding process, a heating unit is brought into contact with a partial area of ​​the surface of the outermost soft magnetic plate, thereby simultaneously pressurizing and heating the area, and the outermost soft magnetic plate is a soft magnetic plate located at one or both ends in the stacking direction among the multiple soft magnetic plates stacked in the lamination process. A rotating electric machine of the present invention includes the laminated core.

[0012] FIG. 1 is a diagram showing an example of the planar shape of an electromagnetic steel sheet. FIG. 2A is a diagram showing an example of the overall configuration of a laminated core manufacturing device. FIG. 2B is a cross-sectional view taken along line I-I of FIG. 2A. FIG. 2C is a cross-sectional view taken along line II-II of FIG. 2A. FIG. 3 is a diagram showing an example of the overall configuration of a laminated core manufacturing device in a state where a heating unit is in contact with the plate surfaces of the electromagnetic steel sheets. FIG. 4A is a diagram showing a first example of a misalignment prevention unit. FIG. 4B is a diagram showing a second example of a misalignment prevention unit. FIG. 5 is a diagram showing an example of a rotating electric machine.

[0013] An embodiment of the present invention will be described below with reference to the drawings. The term "same length, position, size, spacing, etc." refers not only to objects being exactly the same, but also to objects that differ within the scope of the invention (e.g., differences within the tolerances established at the time of design). In each figure, the x-y-z coordinates indicate the orientation relationship in each figure. A symbol with a black circle (●) inside a white circle (○) represents an arrow pointing from the back of the page to the front. A symbol with a cross mark (×) inside a white circle (○) represents an arrow pointing from the front of the page to the back.

[0014] In this embodiment, a laminated core is manufactured by stacking multiple soft magnetic plates, each having an insulating coating formed on the entire surface thereof that exhibits adhesive properties when heated. In the following description, the insulating coating that exhibits adhesive properties when heated is referred to as an adhesive insulating coating as necessary. Note that the plate surface refers to either or both of the front and back surfaces of the soft magnetic plate. The soft magnetic plate includes the base material and the insulating coating. Note that in the following description, the plate surface of a soft magnetic plate in the middle of manufacture refers to either or both of the front and back surfaces of the soft magnetic plate at the time of manufacture. When the insulating coating exhibits adhesive properties, the state of the insulating coating changes from one that cannot adhere to an adherend to one that can adhere to an adherend. Note that the insulating coating is preferably formed so as to cover the entire surface of the soft magnetic plate. The insulating coating may be formed on at least 50% of the total surface area of ​​the soft magnetic plate, preferably at least 70%, and more preferably at least 90%. As described above, the entire plate surface refers to at least 50%, preferably at least 70%, and more preferably at least 90% of the total area of ​​the plate surface. Forming an insulating coating over the entire surface of the soft magnetic plate eliminates the need for fine adjustment of the area where the insulating coating is formed, making laminated core manufacturing more efficient. Furthermore, the larger the area on the surface of the soft magnetic plate where the insulating coating is formed, the more reliably the adherend can be adhered, which is preferable. As will be described later, in this embodiment, the adhesive properties can be exerted in only a portion of the insulating coating, so the area where the insulating coating is formed does not need to coincide with the area where the adhesive properties of the insulating coating are exerted in the bonding process.

[0015] The laminated core is used in, for example, various electrical devices and electronic components. Specific examples of the laminated core include a laminated core included in a transformer, a laminated core (a rotor core and a stator core) included in a rotating electrical machine (a motor and a generator), and a laminated core included in an inductor.

[0016] The soft magnetic plate is a plate made of a soft magnetic material. The soft magnetic plate is, for example, an electromagnetic steel plate. The electromagnetic steel plate may be a grain-oriented electromagnetic steel plate or a non-oriented electromagnetic steel plate. In this embodiment, an example is shown in which a laminated core is manufactured using an electromagnetic steel plate having a bondable insulating coating formed on the entire plate surface. The bondable insulating coating is preferably formed on two plate surfaces (front and back) of the electromagnetic steel plate. This is because the bondable insulating coating is present on two plate surfaces that face each other when multiple electromagnetic steel plates are stacked, allowing for more reliable bonding of the electromagnetic steel plates. However, it is sufficient that the bondable insulating coating is present on the entire surface of at least one of the two plate surfaces that face each other when multiple electromagnetic steel plates are stacked. Therefore, the bondable insulating coating may be formed on only one of the two plate surfaces of the electromagnetic steel plate.

[0017] When a bondable insulating coating exerts its adhesive ability, it changes from a state in which it is unable to adhere an adherend (in this embodiment, an electromagnetic steel sheet) to a state in which it is able to adhere the adherend. Therefore, the state of the bondable insulating coating changes, upon heating, from a state in which it is unable to adhere to an adherend to a state in which it is able to adhere to the adherend. Whether a bondable insulating coating exerts its adhesive ability may be confirmed, for example, by the following method.

[0018] First, two rectangular electromagnetic steel sheets are cut from an electromagnetic steel sheet having the same configuration as the electromagnetic steel sheet used for the laminated core. At this time, the bondable insulating coating formed on the entire surface of the two electromagnetic steel sheets is in an inactive state (i.e., unheated). The two electromagnetic steel sheets measure 30 mm wide x 60 mm long. The leading edge portions of the two electromagnetic steel sheets are then overlapped. The overlapping area (the leading edge portions of the sheet surfaces) measures 30 mm wide x 10 mm long. The two electromagnetic steel sheets with their leading edge portions overlapped are bonded under the following conditions: steel sheet temperature: 180°C, pressure: 10 MPa, and pressure time: 1 hour. The steel sheet temperature (= 180°C) varies depending on the composition of the bondable insulating coating. The steel sheet temperature is set to a temperature above the predetermined temperature at which the bondable insulating coating exhibits its adhesive properties. The two electromagnetic steel sheets bonded in this manner are used as test specimens. The shear tensile strength of the test piece is measured under the conditions of an ambient temperature of 25°C and a tensile speed of 3 mm / min. The shear tensile strength is calculated based on the adhesive area (= 300 mm ２ ) is divided by the adhesive strength (MPa) to calculate the adhesive strength. If the adhesive strength is 2.5 MPa or more, it can be determined that the adhesive insulating coating is exhibiting adhesive ability.

[0019] Alternatively, an electromagnetic steel sheet may be taken from the laminated core, and a test piece having the same configuration as the above-described test piece may be prepared using the taken electromagnetic steel sheet. In this case, if the adhesive strength of the test piece is 2.5 MPa or more, it can be determined that the bondable insulating coating in the laminated core exhibits adhesive properties. Note that an adhesive strength of 2.5 MPa or more of the test piece corresponds to an adhesive strength of 2.5 MPa or more between the electromagnetic steel sheets in the laminated core. Note that if the adhesive strength of the electromagnetic steel sheets in the laminated core is 2.5 MPa or more, it can be determined that the electromagnetic steel sheets are bonded to each other.

[0020] For the purposes of improving insulation performance and suppressing rust, etc., an insulating coating is generally formed on the sheet surface of an electrical steel sheet in a finish annealing line, etc. For example, a bondable insulating coating may be realized by including a thermosetting resin in the insulating coating.

[0021] In this way, when changing an insulating coating typically formed on an electrical steel sheet to a bondable insulating coating, it is necessary to modify the existing manufacturing line. For example, it is necessary to change the operation content and manufacturing equipment depending on whether the insulating coating typically formed on an electrical steel sheet is a bondable insulating coating or not. Furthermore, depending on the composition of the insulating coating typically formed on an electrical steel sheet, it may not be easy to realize a bondable insulating coating that reliably exhibits adhesive properties.

[0022] For this reason, the insulating coating formed on the surface of the electrical steel sheet in a finish annealing line or the like does not have to be a bondable insulating coating (an insulating coating that becomes bondable when heated). In this case, the insulating coating formed on the entire surface of the electrical steel sheet in a finish annealing line or the like is an insulating coating that does not become bondable when heated. In the following description, an insulating coating that does not become bondable when heated will be referred to as an unbondable insulating coating as necessary.

[0023] As described above, the use of a non-bondable insulating coating not only improves the insulating performance of the electrical steel sheet but also suppresses the occurrence of rust on the electrical steel sheet. From this perspective, it is preferable to apply an adhesive that becomes bondable upon heating onto the non-bondable insulating coating, so that a bondable insulating coating is formed over the entire surface of the electrical steel sheet. It is also more preferable that the adhesive that becomes bondable upon heating is an insulating adhesive. In this case, the bondable insulating coating includes an insulating adhesive that becomes bondable upon heating. In the following description, the insulating adhesive that becomes bondable upon heating will be referred to as a sheet-face bonding adhesive as necessary.

[0024] As mentioned above, the entire plate surface means 50% or more of the total area of ​​the plate surface, preferably 70% or more, and more preferably 90% or more. The plate-to-plate bonding adhesive may be formed on 50% or more of the total area of ​​the plate surface of the soft magnetic material plate, preferably 70% or more, and more preferably 90% or more.

[0025] For example, a sheet-face bonding adhesive may be continuously formed on the sheet surface (non-bondable insulating coating) of an electromagnetic steel sheet moving through a production line. The sheet-face bonding adhesive is formed, for example, by baking the sheet-face bonding adhesive onto the non-bondable insulating coating. The movement of the electromagnetic steel sheet through the production line is, for example, performed as follows. First, a coiled electromagnetic steel sheet (electromagnetic steel strip) is set on an uncoiler installed upstream of the production line. Then, the electromagnetic steel sheet is pulled out from the uncoiler and moved from the upstream side to the downstream side of the production line. While the electromagnetic steel sheet is moving, a sheet-face bonding adhesive is continuously formed on the sheet surface of the electromagnetic steel sheet. Then, the electromagnetic steel sheet with the sheet-face bonding adhesive formed thereon is wound into a coil on a coiler installed downstream of the production line.

[0026] The adhesive for plate-to-plate bonding does not have to be formed on a coil-shaped magnetic steel sheet. For example, the adhesive for plate-to-plate bonding may be formed on the surface (non-adhesive insulating coating) of a magnetic steel sheet cut to fit the shape of a laminated core. However, in this case, it takes more time to form the adhesive for plate-to-plate bonding than when the adhesive for plate-to-plate bonding is continuously formed as described above.

[0027] Furthermore, by using an insulating adhesive that exhibits adhesive properties upon heating, it is possible to separate the stacked electromagnetic steel sheets into individual electromagnetic steel sheets, even if the electromagnetic steel sheets are shipped in a stacked state (coiled or cut electromagnetic steel sheets). For example, when an insulating adhesive that exhibits adhesive properties at room temperature is used, if the electromagnetic steel sheets are shipped in a stacked state (coiled or cut electromagnetic steel sheets), the adhesive will exhibit its adhesive properties, making subsequent processing difficult. Furthermore, when an insulating adhesive that exhibits adhesive properties at room temperature is used, it is necessary to process the electromagnetic steel sheets into the desired shape and then apply an adhesive to each sheet surface when stacking the processed electromagnetic steel sheets, resulting in reduced productivity.

[0028] The thickness of the bondable insulating coating is preferably as thin as possible within the range where adhesive properties are exhibited. This is because it is possible to increase the space factor of the laminated core. The space factor of the laminated core is expressed, for example, as the ratio of the total cross-sectional area of ​​the electromagnetic steel sheets that make up the laminated core to the apparent cross-sectional area of ​​the laminated core. Thus, the space factor of the laminated core increases as the volume of the base material (soft magnetic material) included in the laminated core increases.

[0029] The board-to-board bonding adhesive is not limited to a specific adhesive as long as it exhibits adhesive properties upon heating. For example, various adhesives, such as acrylic resin adhesives, cyanoacrylate adhesives, epoxy resin adhesives, polyester adhesives, polyurethane adhesives, melamine resin adhesives, and phenolic resin adhesives, may be used as the board-to-board bonding adhesive. More suitable examples of board-to-board bonding adhesives include thermosetting organic resin adhesives, which undergo a chemical reaction upon heating. Specifically, adhesives whose main components are one or more of resins, such as epoxy resins, phenolic resins, urethane resins, and melamine resins, may be used as the board-to-board bonding adhesive. Furthermore, polyester resins and / or acrylic resins, etc., may be thermoset by adding a crosslinking agent to the resin to be used as the board-to-board bonding adhesive. Furthermore, inorganic adhesives that harden by a dehydration condensation reaction upon heating may also be used as the board-to-board bonding adhesive.

[0030] The plate-face bonding adhesive may also be an anaerobic adhesive. In this case, the plate-face bonding adhesive exerts its adhesive properties by heating and blocking air. Therefore, when bonding the non-bondable insulating coating to the adherend, no space is created between the non-bondable insulating coating and the adherend. For example, the plate-face bonding adhesive may be formed on the non-bondable insulating coating by simultaneously applying the plate-face bonding adhesive on the non-bondable insulating coating, heating the plate-face bonding adhesive, and pressing the non-bondable insulating coating and the plate-face bonding adhesive.

[0031] When a plate-face-to-plate bonding adhesive is formed on the non-bondable insulating coating in this manner, the non-bondable insulating coating and the plate-face-to-plate bonding adhesive can be collectively considered to be a bondable insulating coating.

[0032] The sheet-surface bonding adhesive is preferably an insulating adhesive, as this can improve the insulating performance of the electrical steel sheet. However, for example, if an unbondable insulating coating is formed on the surface of the electrical steel sheet, the sheet-surface bonding adhesive does not need to be an insulating adhesive.

[0033] Furthermore, when no non-bondable insulating coating is formed on the surface of the electromagnetic steel sheet, a bondable insulating coating may be formed on the entire surface of the electromagnetic steel sheet, for example, by applying a sheet-face bonding adhesive to the base material of the electromagnetic steel sheet. When no non-bondable insulating coating is formed on the surface of the electromagnetic steel sheet, an insulating adhesive is used as the sheet-face bonding adhesive. Furthermore, the bondable insulating coating is formed by the sheet-face bonding adhesive.

[0034] As mentioned above, "the entire plate surface" refers to 50% or more of the total area of ​​the plate surface, preferably 70% or more, and more preferably 90% or more. The plate-to-plate adhesion adhesive may be formed on 50% or more of the total area of ​​the plate surface of the soft magnetic plate, preferably 70% or more, and more preferably 90% or more. The method of forming the plate-to-plate adhesion adhesive on the base material of the electromagnetic steel plate may be, for example, the same method as that of forming the plate-to-plate adhesion adhesive on an unbondable insulating coating.

[0035] As described above, the insulating coating itself may be given adhesive properties by adjusting the components and composition of the insulating coating, and the insulating coating may be made into an adhesive insulating coating.

[0036] Alternatively, an adhesive layer may be formed by applying an insulating adhesive that exhibits adhesive properties when heated to the surface of the electrical steel sheet, and the adhesive layer may serve as the adhesive insulating coating. In this case, the adhesive layer has insulating properties and adhesive properties.

[0037] Alternatively, adhesive properties may be imparted to the insulating coating by forming a coating such as an adhesive layer on the insulating coating that exhibits adhesive properties when heated. In this case, the insulating coating and adhesive layer can be collectively considered to be an adhesive insulating coating. An adhesive layer may be partially formed by applying an adhesive to a portion of the surface (above) of an insulating coating formed over the entire surface of the electromagnetic steel sheet. In this case, the adhesive layer may be formed over 50% or more of the total surface area of ​​the soft magnetic material plate, preferably over 70% or more, and more preferably over 90%.

[0038] The soft magnetic plate is not limited to an electromagnetic steel plate. For example, the soft magnetic plate may be an amorphous alloy plate, a nanocrystalline alloy plate, a permendur plate, or a permalloy plate. Furthermore, in a soft magnetic plate without an unbondable insulating coating, a bondable insulating coating may be formed on the base material.

[0039] Insulating coatings that exhibit adhesive properties upon heating exhibit their adhesive properties by shrinking upon heating. Therefore, when an electromagnetic steel sheet having a bondable insulating coating formed on its surface is heated to exert the adhesive properties of the bondable insulating coating, compressive stress may be applied to the electromagnetic steel sheet. Applying compressive stress to an electromagnetic steel sheet may increase iron loss of the electromagnetic steel sheet. Therefore, by partially bonding the sheet surfaces of two adjacent electromagnetic steel sheets in the stacking direction using the adhesive properties of the bondable insulating coating, the compressive stress applied to the electromagnetic steel sheet can be reduced. However, as in the technology described in Patent Document 1, when the means for heating the electromagnetic steel sheets and the means for pressurizing the electromagnetic steel sheets are configured as separate means, bonding the electromagnetic steel sheets is time-consuming. Furthermore, when the electromagnetic steel sheets are bonded during lamination, as in the technology described in Patent Document 2, bonding the electromagnetic steel sheets requires repeated bonding. Therefore, even with the technology described in Patent Document 2, bonding the electromagnetic steel sheets is time-consuming. Therefore, in this embodiment, in order to efficiently bond the magnetic steel sheets together, a laminated core is manufactured by a process including a laminating process and a bonding process, which will be exemplified below.

[0040] (Laminating Process) In the laminating process of this embodiment, multiple magnetic steel sheets are laminated. In the laminating process, the adhesive properties of the bondable insulating coating are not exerted. That is, in the laminating process, the magnetic steel sheets are not heated to a temperature equal to or higher than the temperature at which the adhesive properties of the bondable insulating coating are exerted. The temperature at which the adhesive properties of the bondable insulating coating are exerted is determined, for example, by the specifications of the bondable insulating coating provided by the manufacturer of the bondable insulating coating. When the bondable insulating coating is formed using a plate-to-plate bonding adhesive, the temperature at which the adhesive properties of the bondable insulating coating are exerted is determined, for example, by the specifications of the plate-to-plate bonding adhesive.

[0041] Furthermore, in the lamination process of this embodiment, all of the electromagnetic steel sheets that constitute the laminated core are laminated at once. This reduces the manufacturing man-hours for the lamination process and the bonding process. However, in the lamination process, a number of electromagnetic steel sheets that is fewer than the number of electromagnetic steel sheets that constitute the laminated core may be laminated at once. For example, if there is a risk that all of the electromagnetic steel sheets that constitute the laminated core cannot be reliably bonded at once in the bonding process, a number of electromagnetic steel sheets that is fewer than the number of electromagnetic steel sheets that constitute the laminated core may be laminated at once. For example, in at least one of the cases where the number of laminated electromagnetic steel sheets is large and / or the thickness of the laminated electromagnetic steel sheets is thick, a number of electromagnetic steel sheets that is fewer than the number of electromagnetic steel sheets that constitute the laminated core may be laminated at once.

[0042] Prior to lamination, it is preferable to cut the multiple electromagnetic steel sheets so that their planar shape (the shape of the sheet surfaces) matches the planar shape of the laminated core. The cutting may be performed by a known method, such as punching using a die or cutting using laser light. However, such cutting of the electromagnetic steel sheets does not necessarily have to be performed before the lamination step. For example, the cutting of the electromagnetic steel sheets may be performed after the bonding step. Furthermore, the cutting of the electromagnetic steel sheets may be performed between the lamination step and the bonding step. In this case, the cutting of the electromagnetic steel sheets may be performed, for example, immediately after the multiple electromagnetic steel sheets have been laminated.

[0043] Fig. 1 is a diagram showing an example of the planar shape of an electromagnetic steel sheet. Fig. 1 illustrates a case where an electromagnetic steel sheet 10 is an electromagnetic steel sheet that constitutes a stator core of a radial gap type rotating electrical machine. As mentioned above, the laminated core is not limited to the stator core of a rotating electrical machine.

[0044] (Bonding Process) In the bonding process of this embodiment, the multiple electromagnetic steel sheets stacked in the lamination process are bonded by utilizing the adhesive properties of the bondable insulating coating. Note that, as long as the bonding process is performed after the multiple electromagnetic steel sheets are stacked in the lamination process, the location where the lamination process is performed and the location where the bonding process is performed may be the same or different. Furthermore, in the bonding process of this embodiment, a heating unit is brought into contact with a partial region of the sheet surface of the outermost electromagnetic steel sheet, thereby simultaneously pressurizing and heating the partial region. Note that the partial region of the sheet surface of the electromagnetic steel sheet refers to an area on the sheet surface of the electromagnetic steel sheet that is smaller than the entire area of ​​the sheet surface of the electromagnetic steel sheet. The outermost electromagnetic steel sheet is an electromagnetic steel sheet located at one or both ends in the stacking direction among the multiple electromagnetic steel sheets stacked at the same time in the lamination process. By simultaneously pressurizing and heating the partial region of the sheet surface of the outermost electromagnetic steel sheet, the adhesive properties of the bondable insulating coating are utilized in the partial region. Furthermore, when three or more electromagnetic steel sheets are stacked, a partial region of the outermost electromagnetic steel sheet is pressurized and heated, and at the same time, partial regions of the electromagnetic steel sheets other than the outermost electromagnetic steel sheet are also pressurized and heated. In this case, the bondable insulating coating formed on the sheet surfaces of the electromagnetic steel sheets other than the outermost electromagnetic steel sheet also exhibits adhesive properties in the partial regions. Therefore, in addition to the outermost electromagnetic steel sheet and the electromagnetic steel sheet adjacent to the outermost electromagnetic steel sheet in the stacking direction, the electromagnetic steel sheets other than the outermost layer are also bonded to each other. In other words, all of the multiple electromagnetic steel sheets stacked by the stacking process are simultaneously bonded to adjacent electromagnetic steel sheets in the stacking direction. At this time, the adhesive properties of the bondable insulating coating are exhibited only in partial regions on the sheet surfaces of the electromagnetic steel sheets, so the electromagnetic steel sheets are partially bonded to each other in the partial regions. Note that, because only partial regions of the bondable insulating coating exhibit adhesive properties, even if the bondable insulating coating is formed over the entire sheet surfaces of the electromagnetic steel sheets, the electromagnetic steel sheets can be bonded to each other only in partial regions. Therefore, in the bonding process of this embodiment, multiple electromagnetic steel sheets can be bonded together by applying pressure and heat at once, so that bonding of the electromagnetic steel sheets can be carried out efficiently when manufacturing a laminated core.Furthermore, by bringing the heating portion into contact with a partial region of the sheet surface of the outermost layer of electromagnetic steel sheet, the compressive stress applied to the electromagnetic steel sheet can be reduced (preferably made 0 (zero)) compared to when the heating portion is brought into contact with the entire sheet surface of the outermost layer of electromagnetic steel sheet (applying pressure to the entire sheet surface of the outermost layer of electromagnetic steel sheet).

[0045] Furthermore, in the bonding process, the heating unit may contact only one area on one sheet surface of the outermost electromagnetic steel sheet. However, in this case, depending on the size and shape of the sheet surface of the electromagnetic steel sheet, unless the area on one sheet surface of the outermost electromagnetic steel sheet where the heating unit contacts is wide, there is a risk that the bonding (fixing) of the electromagnetic steel sheet will not be reliable. Widening the area on one sheet surface of the outermost electromagnetic steel sheet where the heating unit contacts may increase the compressive stress applied to the electromagnetic steel sheet. Therefore, in the bonding process of this embodiment, the heating unit contacts multiple areas on one sheet surface of the outermost soft magnetic material plate. In this case, two or more of these multiple areas are positioned apart from each other. Therefore, it is possible to reduce the compressive stress applied to the electromagnetic steel sheet by partially bonding the sheet surfaces of the electromagnetic steel sheets and reduce the risk of insufficient bonding (fixing) of the electromagnetic steel sheets by partially bonding the sheet surfaces of the electromagnetic steel sheets.

[0046] In this embodiment, all of the regions in contact with the heating part on one sheet surface of the outermost magnetic steel sheet are spaced apart from one another. However, the regions in contact with the heating part on one sheet surface of the outermost magnetic steel sheet may include two or more regions that are not spaced apart from one another.

[0047] Furthermore, in the bonding process, the heating portion may be brought into contact with each of the multiple regions on one sheet surface of the outermost electromagnetic steel sheet in sequence. However, doing so does not sufficiently reduce the manufacturing man-hours of the bonding process. Therefore, in the bonding process of this embodiment, multiple heating portions are brought into contact with multiple regions on one sheet surface of the outermost electromagnetic steel sheet simultaneously. This allows the multiple regions to be simultaneously pressurized and heated. Therefore, the manufacturing man-hours of the bonding process can be further reduced. Note that this embodiment illustrates a case in which the heating portions are brought into contact with all of the regions on one sheet surface of the outermost electromagnetic steel sheet that come into contact with the heating portion simultaneously. In this way, the manufacturing man-hours of the bonding process can be further reduced.

[0048] Furthermore, when bringing the heating unit into contact with a partial region of the sheet surface of the outermost layer of electromagnetic steel sheets, the electromagnetic steel sheets may be moved in the direction of the heating unit. However, moving the heating unit is easier than moving the electromagnetic steel sheets. This is because it is necessary to move the electromagnetic steel sheets while they are still stacked in the lamination process. Therefore, in the bonding process of this embodiment, the heating unit is moved in the direction of the electromagnetic steel sheets to bring the heating unit into contact with a partial region of the sheet surface of the outermost layer of electromagnetic steel sheets. In this case, the electromagnetic steel sheets of the multiple electromagnetic steel sheets may also be moved in the direction of the heating unit. In this way, the movement amount of the multiple electromagnetic steel sheets can be made smaller than when the multiple electromagnetic steel sheets are moved in the direction of the heating unit without moving the heating unit, thereby reducing the possibility that the state of the multiple electromagnetic steel sheets will change from the state stacked in the lamination process. However, in order to further reduce the possibility that the state of the multiple electromagnetic steel sheets will change from the stacked state in the lamination process, it is preferable not to move the multiple electromagnetic steel sheets in the direction of the heating part when bringing the heating part into contact with a partial region of the sheet surface of the outermost electromagnetic steel sheet. In this way, not only is the possibility that the state of the multiple electromagnetic steel sheets will change from the stacked state in the lamination process further reduced, but also a means for moving the multiple electromagnetic steel sheets is not required.

[0049] Furthermore, the number of electromagnetic steel sheets bonded by one application of pressure and heat in the bonding step may be at least 2. However, from the viewpoint of reducing the manufacturing man-hours in the laminating step and bonding step, the number of electromagnetic steel sheets bonded by one application of pressure and heat in the bonding step (the number of electromagnetic steel sheets bonded at one time) is preferably at least 3, more preferably at least 0.1 times the total number of electromagnetic steel sheets that make up the laminated core, even more preferably at least 0.5 times the total number of electromagnetic steel sheets that make up the laminated core, and most preferably the total number of electromagnetic steel sheets that make up the laminated core.

[0050] This embodiment illustrates a case where the number of electromagnetic steel sheets bonded by one pressurizing and heating process is the same as the number of electromagnetic steel sheets stacked at one time in the lamination process. Furthermore, in the lamination process of this embodiment, all of the electromagnetic steel sheets constituting the laminated core are stacked at one time. Therefore, in the bonding process of this embodiment, all of the electromagnetic steel sheets constituting the laminated core are bonded at one time by one pressurizing and heating process. However, as described in the section (Lamination Process), for example, if there is a risk that bonding of multiple electromagnetic steel sheets cannot be reliably performed, a number of electromagnetic steel sheets fewer than the number of electromagnetic steel sheets constituting the laminated core may be stacked at one time. In this case, a number of electromagnetic steel sheets fewer than the number of electromagnetic steel sheets constituting the laminated core are bonded at one time by one pressurizing and heating process. Note that each of the electromagnetic steel sheets pressurized and heated at one time is preferably bonded at the same position on the sheet surface.

[0051] Furthermore, another treatment may be performed on the electromagnetic steel sheets simultaneously with the application of pressure and heat in the bonding process. However, for example, cutting the electromagnetic steel sheets simultaneously with the application of pressure and heat in the bonding process increases the likelihood that multiple electromagnetic steel sheets will not be reliably bonded. Therefore, in the bonding process of this embodiment, no other treatment is performed on the electromagnetic steel sheets simultaneously with the application of pressure and heat to a partial region of the sheet surface of the outermost electromagnetic steel sheet. The other treatment includes, for example, cutting the electromagnetic steel sheets. In this way, this embodiment illustrates a case where the bonding process is a dedicated process for bonding multiple electromagnetic steel sheets.

[0052] Note that, for example, depending on the size and shape of the laminated core, there may be a low possibility that cutting the electromagnetic steel sheets simultaneously with applying pressure and heat in the bonding process will not result in reliable bonding of multiple electromagnetic steel sheets. In this case, for example, cutting the electromagnetic steel sheets simultaneously with applying pressure and heat in the bonding process may be performed. In this case, the mold may also function as a heating unit (for example, the mold may have a heating unit). When the heating unit is moved toward the multiple electromagnetic steel sheets as in this embodiment, the heating unit functions as a punch and does not function as a die. Note that when cutting the electromagnetic steel sheets simultaneously with applying pressure and heat in the bonding process, the heating unit does not function as a mold.

[0053] (Laminated Core Manufacturing Apparatus) Figures 2A to 2C are diagrams showing an example of a laminated core manufacturing apparatus used in the bonding step of this embodiment. Note that the modified examples described in the (Laminating Step) and (Bonding Step) sections may be adopted in the laminated core manufacturing apparatus. Figure 2A shows an example of the overall configuration of a laminated core manufacturing apparatus. Figure 2B shows a cross-sectional view taken along line II of Figure 2A. Figure 2C shows a cross-sectional view taken along line II-II of Figure 2A. Note that this embodiment illustrates a case where the electromagnetic steel sheets constituting the laminated core are the electromagnetic steel sheets 10 shown in Figure 1. Furthermore, this embodiment illustrates a case where a plurality of electromagnetic steel sheets 10 are bonded to one another.

[0054] In Fig. 2A , the electromagnetic steel sheet group 100 is formed by stacking a plurality of electromagnetic steel sheets 10. Note that in Fig. 2A , the stacking direction is the z-axis direction. The plurality of electromagnetic steel sheets 10 are stacked so that their respective contours match. In the state shown in Fig. 2A , the plurality of electromagnetic steel sheets 10 have not been heated to a temperature equal to or higher than the temperature at which the adhesive properties of the bondable insulating coatings formed on the sheet surfaces of the plurality of electromagnetic steel sheets 10 are exerted. In other words, in the state shown in Fig. 2A , the adhesive properties of the bondable insulating coatings are not exerted.

[0055] 2A , in this embodiment, the laminated core manufacturing apparatus includes a heating and pressurizing device 200, a control device 230, and a power supply device 240. In addition, in this embodiment, the heating and pressurizing device 200 includes holding units 211 and 221, heating units 212a to 212l and 222a to 222l, and driving units 213 and 223.

[0056] The holders 211 and 221 hold the heating units 212a to 212l and 222a to 222l, respectively, so that they do not shift position. FIGS. 2A to 2C illustrate an example in which the holders 211 and 221 have the same configuration. Specifically, FIGS. 2A to 2C illustrate an example in which the holders 211 and 221 are cylindrical. The holders 211 and 221 may or may not be electrically insulated from the heating units 212a to 212l and 222a to 222l, respectively. Furthermore, the holders 211 and 221 may or may not be magnetically coupled to the heating units 212a to 212l and 222a to 222l, respectively.

[0057] The heating portions 212a to 212l and 222a to 222l come into contact with a partial region of one of the sheet surfaces of the electromagnetic steel sheet 10. When the heating portions 212a to 212l and 222a to 222l in a heated state come into contact with a partial region of one of the sheet surfaces of the electromagnetic steel sheet 10, the region is simultaneously pressurized and heated. Figures 2A to 2C illustrate an example in which the heating portions 212a to 212l and 222a to 222l have the same configuration. Specifically, Figures 2A to 2C illustrate an example in which the heating portions 212a to 212l and 222a to 222l have a cylindrical shape with no opening on the surface facing the outermost electromagnetic steel sheets 10a and 10b.

[0058] Furthermore, in this embodiment, the heating units 212a to 212l and 222a to 222l each include a heating element. The heating elements generate heat, raising the temperature of the surfaces of the heating units 212a to 212l and 222a to 222l. The heating elements may be made of a metallic material or a non-metallic material. This embodiment illustrates a case in which the heating elements generate heat by resistance heating. However, the heating elements do not necessarily have to generate heat by resistance heating. For example, the heating elements may be induction heated by a magnetic field generated by a coil disposed around the heating elements. Note that, for example, the main bodies of the heating units 212a to 212l and 222a to 222l may be the heating elements. Furthermore, for example, the heating elements may be installed in regions of the surfaces of the main bodies of the heating units 212a to 212l and 222a to 222l that are different from the regions that contact a portion of one of the plate surfaces of the electromagnetic steel sheet 10. Furthermore, the heating units 212a to 212l and 222a to 222l do not necessarily have to have a heating element, as will be described later.

[0059] As described above, the heating parts 212a to 212l and 222a to 222l come into contact with a partial region of the sheet surface of one of the electromagnetic steel sheets 10. In this embodiment, the heating parts 212a to 212l come into contact with a partial region of the sheet surface (sheet surface on the negative side of the z-axis) of the electromagnetic steel sheet 10a located at one end in the stacking direction (end on the negative side of the z-axis) of the electromagnetic steel sheets 10 constituting the electromagnetic steel sheet group 100. In addition, in this embodiment, the heating parts 222a to 222l each come into contact with a partial region of the sheet surface (sheet surface on the positive side of the z-axis) of the electromagnetic steel sheet 10b located at the other end in the stacking direction (end on the positive side of the z-axis) of the electromagnetic steel sheets 10 constituting the electromagnetic steel sheet group 100. Of the electromagnetic steel sheets 10 constituting the electromagnetic steel sheet group 100, the electromagnetic steel sheet 10a located at one end in the stacking direction (the end on the negative side of the z-axis) is an example of an outermost layer electromagnetic steel sheet. Therefore, in the following description, the electromagnetic steel sheet 10a located at one end in the stacking direction (the end on the negative side of the z-axis) will be referred to as the outermost layer electromagnetic steel sheet 10a, as necessary. Furthermore, of the electromagnetic steel sheets 10 constituting the electromagnetic steel sheet group 100, the electromagnetic steel sheet 10b located at the other end in the stacking direction (the end on the positive side of the z-axis) is also an example of an outermost layer electromagnetic steel sheet. Therefore, in the following description, the electromagnetic steel sheet 10b located at the other end in the stacking direction (the end on the positive side of the z-axis) will also be referred to as the outermost layer electromagnetic steel sheet 10b, as necessary.

[0060] In the following description, the regions of the heated portions 212a to 212l and 222a to 222l that come into contact with a partial region of one sheet surface of the electromagnetic steel sheet 10 will be referred to as a contact region as necessary. In this embodiment, a case where the contact regions of the heated portions 212a to 212l and 222a to 222l are surfaces will be exemplified. That is, in this embodiment, a case where the heated portions 212a to 212l and 222a to 222l come into surface contact with a partial region of one sheet surface of the electromagnetic steel sheet 10 will be exemplified. In this way, the risk of insufficient adhesion (fixing) of the electromagnetic steel sheet 10 can be reduced without increasing the number of contact regions. However, the heated portions 212a to 212l and 222a to 222l may come into point contact with a partial region of one sheet surface of the electromagnetic steel sheet 10. Furthermore, in this embodiment, the distances (in the z-axis direction) from the holding portions 211 and 221 to the contact regions of the heating portions 212a to 212l and 222a to 222l are the same. Therefore, in this embodiment, the contact regions of the heating portions 212a to 212l and the contact regions of the heating portions 222a to 222l simultaneously contact a partial region of the sheet surface of the outermost layer electromagnetic steel sheet 10a and a partial region of the sheet surface of the outermost layer electromagnetic steel sheet 10b, respectively.

[0061] In this embodiment, the heating elements 212a-212l and 222a-222l (the aforementioned heating elements) generate heat so that the temperature of the contact areas of the heating elements 212a-212l and 222a-222l reaches or exceeds the temperature at which the bondable insulating coating exhibits its adhesive properties. Of the regions of the heating elements 212a-212l and 222a-222l, at least the contact areas of the heating elements 212a-212l and 222a-222l are preferably made of a material that does not contain metal ions. The bondable insulating coating does not exhibit adhesive properties to materials that do not contain metal ions (such as ceramics). Therefore, the magnetic steel sheet 10 is not bonded to the heating elements 212a-212l and 222a-222l. Note that all regions of the heating elements 212a-212l and 222a-222l may be made of a material that does not contain metal ions. Furthermore, the holding portions 211, 221 and the heating portions 212a to 212l, 222a to 222l are configured so that their mechanical strength is not reduced (deformed) by heat generation from the heating portions 212a to 212l, 222a to 222l and contact with the electromagnetic steel sheet 10.

[0062] 2A to 2C illustrate a case in which the contact areas of the heating units 212a to 212l and 222a to 222l come into contact with the planned heating regions 11a to 11l, which are surrounded by the two-dot chain lines drawn on the sheet surface of the electromagnetic steel sheet 10 in FIG. 1 . Note that the two-dot chain lines shown in FIG. 1 are imaginary lines. If the total area of ​​the planned heating regions 11a to 11l (the sum of the areas of the individual planned heating regions 11a to 11l) is too large, there is a risk that the compressive stress applied to the electromagnetic steel sheet 10 will be large. On the other hand, if the total area of ​​the planned heating regions 11a to 11l is too small, there is a risk that the bonding (fixing) of the electromagnetic steel sheet 10 will be insufficient. Furthermore, if the planned heating regions 11a to 11l are unevenly positioned, there is a risk that the bonding (fixing) of the electromagnetic steel sheet 10 will be insufficient. The number, positions, and sizes of the planned heating regions 11a to 11l are determined in advance based on the above considerations.

[0063] For example, prior to mass production of laminated cores, multiple prototypes of the heating and pressing device 200 are fabricated, each differing in at least one of the number, position, shape, and size of the contact areas of the heating unit. The number, position, shape, and size of the contact areas of the heating unit correspond to the number, position, shape, and size of the areas to be heated on the electromagnetic steel sheet 10. Multiple prototypes of the heating and pressing device 200 are manufactured. The iron loss of the multiple prototype laminated cores manufactured in this manner is measured. Furthermore, the presence or absence of delamination of the electromagnetic steel sheets in the multiple prototype laminated cores is confirmed. A prototype laminated core is identified that has an iron loss equal to or less than the iron loss required for the laminated core and that does not have delamination of the electromagnetic steel sheets. The number, position, shape, and size of the contact areas of the heating unit used in manufacturing the identified prototype laminated cores are adopted as the number, position, shape, and size of the contact areas of the heating units 212a to 212l and 222a to 222l of the heating and pressing device 200. As described above, the number, positions, and sizes of the contact areas of the heating units 212a to 212l and 222a to 222l may be determined by trial and error. Therefore, the number, positions, shapes, and sizes of the contact areas of the heating units 212a to 212l and 222a to 222l of the heating and pressure application device 200 are not limited to those shown in Figures 2A to 2C.

[0064] From the viewpoint of simultaneously reducing the compressive stress applied to the electromagnetic steel sheet and reducing the risk of insufficient bonding (fixing) of the electromagnetic steel sheet, it is preferable that the contact area of ​​the heating part that contacts one sheet surface of the electromagnetic steel sheet 10 be as follows. First, a preferred example of the number of contact areas of the heating part that contacts one sheet surface of the electromagnetic steel sheet 10 when the laminated core is a stator core and a rotor core will be described. When the laminated core is a stator core, the number of teeth of the stator core is defined as Nt. When the laminated core is a rotor core, the number of teeth of the stator core that is paired with the rotor core is defined as Nt. The number of contact areas of the heating part that contacts one sheet surface of the electromagnetic steel sheet 10 may be, for example, 0.3×Nt or more and 6.0×Nt or less, preferably 0.4×Nt or more and 4.0×Nt or less, and more preferably 0.5×Nt or more and 2.0×Nt or less. FIG. 1 illustrates an example where the number of teeth Nt of the stator core is 6. 2A to 2C illustrate an example in which the number of heating portions 212a to 212l and 222a to 222l is 12. Therefore, in this embodiment, an example is illustrated in which the number of contact areas of heating portions 212a to 212l and 222a to 222l that come into contact with one plate surface of electromagnetic steel sheets 10a and 10b is 2.0×Nt.

[0065] The number of contact areas of the heating part may be, for example, three or more, or four or more, or even six or more, or twelve or more. The ratio of the total area of ​​the contact areas of the heating part on one sheet surface to the area of ​​the sheet surface of the electromagnetic steel sheet 10 is, for example, preferably 5% or more and 70% or less, and more preferably 10% or more and 50% or less. For example, the area of ​​one sheet surface of the electromagnetic steel sheet 10 may be divided into two or more and 20 or less, or three or more and 20 or less, so that each area is the same, and at least one contact area of ​​the heating part may be present in each of the obtained multiple divided regions.

[0066] As described above, the number, position, shape, and size of the planned heating regions of the electromagnetic steel sheet 10 are determined in accordance with the number, position, shape, and size of the contact regions of the heating units. FIG. 1 illustrates planned heating regions 11a to 11l determined in accordance with the heating units 212a to 212l and 222a to 222l shown in FIGS. 2A to 2C. That is, the example illustrates a case in which the contact regions of the heating units 212a to 212l contact the planned heating regions 11a to 11l. Note that, assuming that the sheet surface of the electromagnetic steel sheet 10 shown in FIG. 1 is a view from the positive side of the z-axis (assuming that the orientation of the z-axis in the x-y-z coordinate system is opposite to that shown in FIG. 1), the contact regions of the heating units 222a to 222l also contact the planned heating regions 11a to 11l.

[0067] The adhesive ability of the bondable insulating coating is exerted in a portion of one surface region of the electromagnetic steel sheet 10, but not in other regions of the surface region. In the example shown in FIG. 1 , the adhesive ability of the bondable insulating coating is exerted, for example, in the intended heating regions 11a-11l of one surface region of the electromagnetic steel sheet 10, but not in other regions of the surface region. Two or more of the regions in which the adhesive ability of the bondable insulating coating is exerted are located apart from each other. Note that the intended heating regions 11a-11l may or may not coincide with the regions in which the adhesive ability of the bondable insulating coating is exerted. For example, the adhesive ability of the bondable insulating coating may be exerted in an area wider than the intended heating regions 11a-11l. Conversely, the adhesive ability of the bondable insulating coating may be exerted in an area narrower than the intended heating regions 11a-11l. However, it is preferable that the number of regions where the bondable insulating coating exhibits its adhesive properties be the same as the number of intended heating regions 11a-11l on one surface of the magnetic steel sheet 10. Among the regions where the bondable insulating coating exhibits its adhesive properties, the number of regions that are located apart from one another are counted as the number of regions where the bondable insulating coating exhibits its adhesive properties. In other words, each of the regions where the bondable insulating coating exhibits its adhesive properties is a continuous region.

[0068] Drive units 213 and 223 are attached to the holding units 211 and 221, respectively. The drive unit 213 moves the holding unit 211 and the heating units 212a to 212l in the stacking direction (z-axis direction) to bring the contact areas of the heating units 212a to 212l into contact with partial areas (to-be-heated areas 11a to 11l) of the sheet surface of the outermost layer of electromagnetic steel sheet 10a. The drive unit 223 moves the holding unit 221 and the heating units 222a to 222l in the stacking direction to bring the contact areas of the heating units 222a to 222l into contact with partial areas of the sheet surface of the outermost layer of electromagnetic steel sheet 10b. Figure 3 is a diagram showing an example of the overall configuration of a laminated core manufacturing apparatus in a state in which the heating units 212a to 212l and 222a to 222l are in contact with partial areas of the sheet surfaces of the outermost layer of electromagnetic steel sheets 10a and 10b, respectively, in this manner. In this embodiment, the state of the heating and pressurizing device 200 includes the state shown in FIG. 2A and the state shown in FIG.

[0069] The driving units 213, 223 include, for example, hydraulic cylinders. If the pressure applied to the electromagnetic steel sheet group 100 by the heating units 212a-212l, 222a-222l contacting partial regions of the sheet surfaces of the outermost electromagnetic steel sheets 10a, 10b is too small, there is a risk that the bonding (fixing) of the electromagnetic steel sheets 10 will be insufficient. Conversely, if the pressure is too large, there is a risk that the positions of the electromagnetic steel sheets 10 constituting the electromagnetic steel sheet group 100 will be significantly shifted in the sheet surface direction (the x-y plane direction in Figures 1 to 3 ) of the electromagnetic steel sheet group 100. In the following description, this pressure will be referred to as the pressure applied to the electromagnetic steel sheet group 100 as necessary. Furthermore, if the surface temperature of the bondable insulating coating is too low, there is a risk that the adhesive ability of the bondable insulating coating will not be exerted or that the bonding (fixing) of the electromagnetic steel sheets 10 will be insufficient. There is also a risk that the number of steps in the contacting process will increase. Conversely, if the surface temperature of the bondable insulating coating is too high, the temperature of the magnetic steel sheet 10 may exceed the heat resistance temperature of the bondable insulating coating, or the magnetic steel sheet 10 may not be sufficiently bonded (fixed). The surface temperature of the bondable insulating coating may be obtained, for example, by actually measuring the temperature of a predetermined region on the surface of the bondable insulating coating. The predetermined region may be, for example, a region on the surface of the bondable insulating coating that is as close as possible to the intended heating regions 11a to 11l. The surface temperature of the bondable insulating coating may also be a calculated value.

[0070] The pressure applied to the electromagnetic steel sheet group 100 and the surface temperature of the bondable insulating coating are predetermined based on the above considerations. For example, prior to mass production of laminated cores, multiple prototypes of laminated cores are manufactured under different conditions for at least one of the pressure applied to the electromagnetic steel sheet group 100 and the surface temperature of the bondable insulating coating. The positions of the electromagnetic steel sheets in the sheet surface direction of the multiple prototype laminated cores are confirmed. Also, the presence or absence of peeling of the electromagnetic steel sheets in the multiple prototype laminated cores is confirmed. A prototype laminated core is identified in which the positional deviation of the electromagnetic steel sheets in the sheet surface direction is less than the deviation amount required for a laminated core and in which there is no peeling of the electromagnetic steel sheets. The manufacturing conditions (pressure applied to the electromagnetic steel sheet group 100 and surface temperature of the bondable insulating coating) used when the identified prototype laminated core was manufactured are adopted as the actual manufacturing conditions. When determining the actual manufacturing conditions in this manner, the time during which the heating units 212a to 212l and 222a to 222l are in contact with a portion of the sheet surface of the outermost magnetic steel sheets 10a and 10b may be a constant time (fixed value). The time may be varied in addition to or instead of the pressure applied to the magnetic steel sheet group 100 and the surface temperature of the bondable insulating coating.

[0071] From the viewpoint of simultaneously reducing the risk that the bonding (fixing) of the electromagnetic steel sheets will be insufficient and reducing the risk that the positions of the electromagnetic steel sheets 10 constituting the electromagnetic steel sheet group 100 will be significantly shifted in the sheet surface direction, the pressure applied to the electromagnetic steel sheet group 100 is, for example, preferably 0.5 MPa or more and 70 MPa or less, and more preferably 3 MPa or more and 30 MPa or less. From the viewpoint of simultaneously reducing the risk that the bonding (fixing) of the electromagnetic steel sheets will be insufficient and reducing the number of steps in the bonding process, the surface temperature of the bondable insulating coating is, for example, preferably 100°C or more and 300°C or less, and more preferably 150°C or more and 250°C or less.

[0072] The power supply device 240 supplies power to the heating units 212a-212l and 222a-222l. The magnitude of the power is predetermined, for example, so that the surface temperature of the bondable insulating coating is equal to or higher than the temperature at which the bondable insulating coating exhibits its adhesive properties. The preferred range of the surface temperature of the bondable insulating coating is as described above. For convenience of illustration, only the lines connecting the power supply device 240 and the heating units 212a and 222g are shown in FIGS. 2A and 3. However, the power supply device 240 is electrically connected to the heating units 212a-212l and 222a-222l so that power can be supplied to each of the heating units 212a-212l and 222a-222l collectively or individually. As described above, this embodiment illustrates a case where the heating elements of the heating units 212a-212l and 222a-222l generate heat by resistance heating. In this case, the power supply device 240 is electrically connected to the heating element and supplies AC or DC current to the heating element.

[0073] The control device 230 controls the operation of the drive units 213, 223 and the power supply device 240. The hardware of the control device 230 includes one or more hardware processors, such as a CPU (Central Processing Unit). The hardware of the control device 230 also includes one or more memories, such as a RAM (Random Access Memory) and a ROM (Read Only Memory). The control device 230 performs various calculations by executing one or more programs stored in the memory using one or more hardware processors. The hardware of the control device 230 also includes an input device and an output device. The control device 230 may also be implemented by dedicated hardware, such as an ASIC (Application Specific Integrated Circuit), or a PLC (Programmable Logic Controller).

[0074] Here, an example of the processing by the control device 230 will be described, taking as an example a case where the initial positions of the holding units 211, 221 and the heating units 212a to 212l, 222a to 222l are the positions shown in FIG. 2A.

[0075] For example, an operator issues a work start instruction to the control device 230 by operating an input device of the control device 230. Based on the work start instruction, the control device 230 outputs a contact instruction signal to the driving units 213 and 223. Based on the contact instruction signal, the driving units 213 and 223 move the holding units 211 and 221 and the heating units 212a to 212l and 222a to 222l, which are in their initial positions, toward the electromagnetic steel sheet group 100. The movement of the holding units 211 and 221 and the heating units 212a to 212l and 222a to 222l continues until a predetermined pressure is applied to the electromagnetic steel sheet group 100 by the heating units 212a to 212l and 222a to 222l. The predetermined pressure is the pressure applied to the electromagnetic steel sheet group 100 described above. In this way, the state shown in FIG. 2A changes to the state shown in FIG. 3. Whether or not a predetermined pressure is applied to the electromagnetic steel sheet group 100 is determined, for example, based on the measured or calculated value of the pressure applied to the electromagnetic steel sheet group 100, or the measured or calculated value of a physical quantity that can be converted to that pressure (for example, the measured or calculated value of the oil pressure in a hydraulic cylinder).

[0076] When a predetermined pressure is applied to the electromagnetic steel sheet group 100, the control device 230 outputs a power supply command signal to the power supply device 240. The power supply device 240 supplies power to the heating units 212a to 212l and 222a to 222l based on the power supply command signal. When a predetermined time has elapsed since the supply of power to the heating units 212a to 212l and 222a to 222l began, the control device 230 outputs a power stop command signal to the power supply device 240. The predetermined time is, for example, the fixed time (fixed value) described above.

[0077] Based on the power supply stop signal, the power supply device 240 stops the supply of power to the heating units 212a-212l and 222a-222l. Furthermore, the control device 230 outputs a standby command signal to the driving units 213 and 223. Based on the standby command signal, the driving units 213 and 223 move the holding units 211 and 221 and the heating units 212a-212l and 222a-222l and return them to their initial positions. In this manner, the holding units 211 and 221 and the heating units 212a-212l and 222a-222l change from the state shown in FIG. 3 to the state shown in FIG. 2A. As described above, in this embodiment, a heating treatment unit is realized by using, for example, the control device 230 and the power supply device 240. Furthermore, in this embodiment, a pressure treatment unit is realized by using, for example, the holding units 211 and 221, the driving units 213 and 223, and the control device 230.

[0078] Here, an example has been given in which the operation of the holding units 211, 221 and the heating units 212a-212l, 222a-222l in the bonding process is automatically performed by the control unit 230. However, this is not necessarily the case. For example, the operation of the holding units 211, 221 and the heating units 212a-212l, 222a-222l may be performed manually by an operator. Furthermore, the power supply device 240 may be turned on and off by an operator. Furthermore, the power supply device 240 may be turned on before the heating units 212a-212l, 222a-222l come into contact with the intended heating regions 11a-11l of the electromagnetic steel sheets 10a, 10b. For example, a power stop command signal may be output to the power supply device 240 before a predetermined pressure is applied to the electromagnetic steel sheet group 100. As described above, in the present embodiment, as long as the intended heating regions 11a to 11l of the electromagnetic steel sheets 10a and 10b are simultaneously pressurized and heated in the bonding step, the timing at which heating of the intended heating regions 11a to 11l of the electromagnetic steel sheets 10a and 10b begins may be before or after the multiple heating units 212a to 212l and 222a to 222l come into contact with the intended heating regions 11a to 11l of the electromagnetic steel sheets 10a and 10b. Furthermore, heating of the intended heating regions 11a to 11l of the electromagnetic steel sheets 10a and 10b may begin at the same time as the multiple heating units 212a to 212l and 222a to 222l come into contact with the intended heating regions 11a to 11l of the electromagnetic steel sheets 10a and 10b.

[0079] As described above, the lamination process of this embodiment illustrates a case in which all of the electromagnetic steel sheets 10 constituting the laminated core are laminated at once. In this case, in the bonding process, the electromagnetic steel sheets 10 are heated in a state in which all of the electromagnetic steel sheets 10 constituting the laminated core are laminated. However, as described above, for example, if there is a risk that all of the electromagnetic steel sheets constituting the laminated core cannot be reliably bonded at once in the bonding process, a number of electromagnetic steel sheets fewer than the number of electromagnetic steel sheets constituting the laminated core may be laminated at once in the lamination process. In this case, the lamination process and the bonding process are each performed multiple times. Even in this case, from the viewpoint of reducing the manufacturing man-hours in the lamination process and the bonding process, it is preferable to bond a large number of electromagnetic steel sheets in one bonding process. Note that when N (N≧2) electromagnetic steel sheet groups, each of which has a plurality of electromagnetic steel sheets 10 laminated therein, are bonded in a single bonding process, (N−1)×2 electromagnetic steel sheets 10 are bonded at once.

[0080] FIG. 5 is a diagram showing an example of the configuration of a device having a laminated core manufactured using the laminated core manufacturing method (and manufacturing apparatus) of this embodiment. The device (laminated core) may be manufactured by adopting the modified examples described in the sections (Laminating Process), (Bonding Process), and (Laminated Core Manufacturing Apparatus). FIG. 5 illustrates a case where the device is a rotating electric machine. FIG. 5 also shows a cross section of the rotating electric machine cut perpendicularly to the center line 0 of the rotating electric machine. A side view of the rotating electric machine may resemble, for example, the area of ​​the electromagnetic steel sheet group 100 shown in FIG. 3.

[0081] 5, the rotating electric machine has a stator 510 and a rotor 520. The stator 510 has a stator core 511 and a stator coil 512. The rotor 520 has a rotor core 521 and permanent magnets 522a to 522l.

[0082] As described above, the number of contact areas of the heating portion that come into contact with one plate surface of the electromagnetic steel sheet 10 may be, for example, 0.3×Nt or more and 6.0×Nt or less, preferably 0.4×Nt or more and 4.0×Nt or less, and more preferably 0.5×Nt or more and 2.0×Nt or less. When the laminated core manufactured using the laminated core manufacturing method of this embodiment is a stator core 511, Nt is the number of teeth of the stator core 511. When the laminated core manufactured using the laminated core manufacturing method of this embodiment is a rotor core 521, Nt is the number of teeth of the stator core 511 that is paired with the rotor core 521.

[0083] As described above, the adhesiveness of the bondable insulating coating is exerted in a partial region of one sheet surface of the electromagnetic steel sheet 10. The number of regions where adhesiveness is exerted on one sheet surface of the electromagnetic steel sheet constituting the laminated core manufactured using the manufacturing method for a laminated core of this embodiment is preferably the same as the number of contact areas of the heating unit that contacts one sheet surface of the electromagnetic steel sheet 10. As described above, among the regions where adhesiveness of the bondable insulating coating is exerted, the number of regions that are located apart from each other is counted as the number of regions where adhesiveness of the bondable insulating coating is exerted. In the laminated core of this embodiment, adjacent electromagnetic steel sheets in the stacking direction are bonded to each other in the regions where adhesiveness of the bondable insulating coating is exerted on the sheet surface of the electromagnetic steel sheet. Therefore, the number of regions where adhesiveness is exerted on one sheet surface of the electromagnetic steel sheet constituting the laminated core is the same as the number of regions where the electromagnetic steel sheet is bonded to the adjacent electromagnetic steel sheet in the stacking direction. The number of regions on one surface of an electromagnetic steel sheet constituting a laminated core manufactured using the manufacturing method for a laminated core of this embodiment that are bonded to the surface of an adjacent soft magnetic sheet in the lamination direction may be, for example, 0.3×Nt or more and 6.0×Nt or less, preferably 0.4×Nt or more and 4.0×Nt or less, and more preferably 0.5×Nt or more and 2.0×Nt or less. Note that, for example, in the process of extracting the electromagnetic steel sheets from the laminated core and disassembling them into individual electromagnetic steel sheets, the number of regions to which the electromagnetic steel sheets are bonded can be confirmed by photographing the plate surfaces of the disassembled electromagnetic steel sheets and analyzing the images or by visually determining the regions to which the electromagnetic steel sheets are bonded.

[0084] Both the stator core 511 and the rotor core 521 may be laminated cores manufactured using the laminated core manufacturing method of this embodiment. Of the stator core 511 and the rotor core 521, only the stator core 511 may be a laminated core manufactured using the laminated core manufacturing method of this embodiment. Of the stator core 511 and the rotor core 521, only the rotor core 521 may be a laminated core manufactured using the laminated core manufacturing method of this embodiment. When the laminated core manufactured using the laminated core manufacturing method of this embodiment is the stator core 511, for example, the matters described in the sections (Laminating Process), (Bonding Process), and (Laminated Core Manufacturing Apparatus) apply to a plurality of electromagnetic steel sheets whose planar shape follows the outline of the stator core 511 shown in FIG. 5 . Note that FIG. 5 illustrates an example in which the stator core 511 is manufactured by stacking a plurality of electromagnetic steel sheets 10 having the planar shape shown in FIG. 1 . Furthermore, when the laminated core manufactured using the laminated core manufacturing method of this embodiment is rotor core 521, for example, the matters described in the sections (Laminating process), (Bonding process), and (Laminated core manufacturing apparatus) apply to a plurality of electromagnetic steel sheets whose planar shape is a shape that follows the outline of rotor core 521 shown in Figure 5.

[0085] 5 illustrates an example in which the stator core 511 has six teeth 511a to 511f. Therefore, FIG. 5 illustrates an example in which Nt is 6. Note that the configuration of the IPM motor is not limited to the configuration illustrated in FIG. 5, as long as at least one of the stator core and the rotor core is manufactured using the laminated core manufacturing method of this embodiment. For example, a flux barrier may be formed on the rotor core.

[0086] 5 illustrates an example in which the rotating electric machine is an interior permanent magnet (IPM) motor. However, the rotating electric machine is not limited to an IPM motor. For example, the rotating electric machine may be a motor other than an IPM motor. Furthermore, the rotating electric machine may be a generator.

[0087] (Summary) As described above, in this embodiment, the electromagnetic steel sheet group 100 is produced by stacking multiple electromagnetic steel sheets 10. An insulating coating (bondable insulating coating) that exhibits adhesive properties when heated is formed on the sheet surfaces of the electromagnetic steel sheets 10. By contacting the heating sections 212a-212l and 222a-222l with the intended heating regions 11a-11l of the outermost electromagnetic steel sheets 10a and 10b of the electromagnetic steel sheet group 100, the intended heating regions 11a-11l are simultaneously pressurized and heated. Therefore, when manufacturing a laminated core, the electromagnetic steel sheets 10 can be efficiently bonded together. Furthermore, compared to when pressure is applied to the stacked multiple electromagnetic steel sheets 10 at different times and when the stacked multiple electromagnetic steel sheets 10 are heated, the possibility of misalignment of the electromagnetic steel sheets 10 in the sheet surface direction (the x-y plane direction in FIGS. 1 to 3 ) can be reduced. Furthermore, since the heating sections 212a to 212l and 222a to 222l perform the roles of heating and pressurizing, the device can be made compact.

[0088] Furthermore, in the present embodiment, in the bonding step, heating units 212a-212l, 222a-222l are brought into contact with a plurality of planned heating regions 11a-11l of outermost electromagnetic steel sheets 10a, 10b. Therefore, by partially bonding the sheet surfaces of electromagnetic steel sheets 10 together, it is possible to both reduce the compressive stress applied to electromagnetic steel sheets 10 and reduce the risk that bonding (fixing) of electromagnetic steel sheets 10 will be insufficient by partially bonding the sheet surfaces of electromagnetic steel sheets 10 together.

[0089] In this embodiment, in the bonding process, the heating portions 212a-212l and 222a-222l are simultaneously brought into contact with the heating regions 11a-11l of the outermost electromagnetic steel sheets 10a and 10b. This allows the heating regions 11a-11l to be pressurized and heated simultaneously. This allows the bonding of the electromagnetic steel sheets 10 together to be more efficient when manufacturing a laminated core.

[0090] Furthermore, in this embodiment, by moving the heating units 212a to 212l and 222a to 222l toward the electromagnetic steel sheets 10 in the bonding step, the heating units 212a to 212l and 222a to 222l are brought into contact with the intended heating regions 11a to 11l of the outermost electromagnetic steel sheets 10a and 10b. This reduces the amount of movement of the electromagnetic steel sheets 10 in the bonding step, thereby reducing the possibility of misalignment of multiple electromagnetic steel sheets.

[0091] In this embodiment, the number of electromagnetic steel sheets 10 bonded by one application of pressure and heat in the bonding step is set to 3 or more. Therefore, when manufacturing a laminated core, bonding of the electromagnetic steel sheets 10 to each other can be performed more efficiently.

[0092] Furthermore, in this embodiment, the intended heating regions 11a to 11l of the outermost electromagnetic steel sheets 10a, 10b are pressurized and heated without cutting the electromagnetic steel sheets at the same time, which makes it possible to further prevent, for example, the inability to reliably bond multiple electromagnetic steel sheets.

[0093] (Modification) In the present embodiment, the heating units 212a to 212l and 222a to 222l each have a heating element. However, this is not necessarily the case as long as partial pressure and heating are applied to and partial heat applied to the sheet surfaces of the outermost magnetic steel sheets 10a and 10b simultaneously. For example, the following may be adopted.

[0094] The heating units 212a to 212l and 222a to 222l may each include a laser oscillator. The laser oscillator heats a partial region of the sheet surface of the outermost electromagnetic steel sheets 10a and 10b by irradiating the partial region of the sheet surface of the outermost electromagnetic steel sheets 10a and 10b with laser light. For example, the heating units 212a to 212l and 222a to 222l irradiate a partial region of the sheet surface of the outermost electromagnetic steel sheets 10a and 10b with laser light when in contact with the sheet surface of the outermost electromagnetic steel sheets 10a and 10b.

[0095] To achieve this, for example, a hollow portion that opens onto the surface of the heating portions 212a to 212l, 222a to 222l that faces the outermost electromagnetic steel sheets 10a, 10b may be formed in the heating portions 212a to 212l, 222a to 222l. A laser oscillator may be installed in the hollow portion of the heating portions 212a to 212l, 222a to 222l. Furthermore, instead of laser light, electromagnetic waves other than laser light (for example, infrared rays) may be irradiated onto a partial region of the sheet surface of the outermost electromagnetic steel sheets 10a, 10b, thereby heating the partial region of the sheet surface of the outermost electromagnetic steel sheets 10a, 10b.

[0096] Furthermore, the heating parts 212a to 212l and 222a to 222l may be used as electrodes. In this case, a potential may be applied to the heating parts 212a to 212l and 222a to 222l while the heating parts 212a to 212l and 222a to 222l are in contact with partial regions of the sheet surfaces of the outermost layer electromagnetic steel sheets 10a and 10b. In this case, partial regions of the sheet surfaces of the outermost layer electromagnetic steel sheets 10a and 10b may be heated by current flowing through the heating parts 212a to 212l, the electromagnetic steel sheet group 100, and the heating parts 222a to 222l.

[0097] As described in this embodiment, when the heating parts 212a to 212l and 222a to 222l generate heat, contact heating is performed by the heating parts 212a to 212l and 222a to 222l. Even when the heating parts 212a to 212l and 222a to 222l are used as electrodes, contact heating is also performed by the heating parts 212a to 212l and 222a to 222l. In these cases, on the sheet surfaces of the outermost magnetic steel sheets 10a and 10b, the areas in contact with the heating parts 212a to 212l and 222a to 222l and the areas that receive heat from the heating parts 212a to 212l and 222a to 222l are the same. On the other hand, when a laser oscillator is installed in a hollow portion that opens on the side of the outermost electromagnetic steel sheet 10a, 10b as described above, non-contact heating is performed by the heating units 212a-212l, 222a-222l. In this case, on the sheet surfaces of the outermost electromagnetic steel sheets 10a, 10b, the regions in contact with the heating units 212a-212l, 222a-222l and the regions that receive heat from the heating units 212a-212l, 222a-222l are different regions. For example, when the contact regions of the heating units 212a-212l, 222a-222l are hollow circular, the regions in contact with the heating units 212a-212l, 222a-222l are, for example, regions obtained by excluding a region having a diameter equal to the outer diameter of the hollow circle from a region having a diameter equal to the inner diameter of the hollow circle. On the other hand, the area receiving heat from the heating portions 212a to 212l and 222a to 222l (area irradiated with laser light) is, for example, all or part of the hollow portion of the hollow circle (the circular area whose diameter is the inner diameter of the hollow circle).

[0098] As described above, if the heating portions 212a to 212l, 222a to 222l come into contact with a partial region of the sheet surface of the outermost electromagnetic steel sheets 10a, 10b, and the region is heated when pressurized, the region on the sheet surface of the outermost electromagnetic steel sheets 10a, 10b that comes into contact with the heating portions 212a to 212l, 222a to 222l and the region that receives heat from the heating portions 212a to 212l, 222a to 222l may be the same as or different from each other.

[0099] Furthermore, in the present embodiment, the case where the heating parts 212a to 212l and 222a to 222l are in contact with both of the sheet surfaces of the outermost electromagnetic steel sheets 10a and 10b has been exemplified. However, this is not necessarily the case. The heating parts 212a to 212l or 222a to 222l may be in contact with only one of a partial region of the sheet surface of the outermost electromagnetic steel sheet 10a and a partial region of the sheet surface of the outermost electromagnetic steel sheet 10b. In this case, for example, the bonding process may be performed by placing the electromagnetic steel sheet group 100 on a stand so that the sheet surfaces of the outermost electromagnetic steel sheet 10a and the outermost electromagnetic steel sheet 10b that are not in contact with the heating parts 212a to 212l or 222a to 222l face downward.

[0100] Furthermore, in order to further reduce the possibility of misalignment of the electromagnetic steel sheets 10 in the sheet surface direction, the bonding process may be performed with one or more misalignment prevention parts arranged so as to face the side surfaces of the plurality of electromagnetic steel sheets 10 (electromagnetic steel sheet group 100) stacked in the stacking process. Fig. 4A is a diagram showing a first example of a misalignment prevention part. Fig. 4B is a diagram showing a second example of a misalignment prevention part. Figs. 4A and 4B are diagrams showing the electromagnetic steel sheet group 100 as viewed from the stacking direction (z-axis direction).

[0101] FIG. 4A illustrates a hollow misalignment prevention part 410. FIG. 4A illustrates a case where the hollow misalignment prevention part 410 has a hollow cylindrical shape. The electromagnetic steel sheet group 100 is disposed in the hollow part of the hollow misalignment prevention part 410. Therefore, the inner diameter of the misalignment prevention part 410 is equal to or greater than the outer diameter of the electromagnetic steel sheets 10. In this case, the shorter the distance between the hollow misalignment prevention part 410 and the electromagnetic steel sheet group 100, the better. For example, the distance between the hollow misalignment prevention part 410 and the electromagnetic steel sheet group 100 is preferably 5 mm or less, more preferably 3 mm or less, and even more preferably 1 mm or less. Furthermore, it is preferable that the inner wall surface of the hollow misalignment prevention part 410 faces the entire side surface of the electromagnetic steel sheet group 100 (the edges of the sheet surfaces of all the electromagnetic steel sheets 10 stacked in the stacking process). In this case, the length in the stacking direction of the electromagnetic steel sheets may be the same for the hollow misalignment prevention part 410 and the multiple electromagnetic steel sheets 10 (electromagnetic steel sheet group 100) stacked in the stacking process. Also, in this case, the length in the stacking direction of the electromagnetic steel sheets may be longer for the hollow misalignment prevention part 410 than for the multiple electromagnetic steel sheets 10 (electromagnetic steel sheet group 100) stacked in the stacking process. Note that the shape of the hollow part of the hollow misalignment prevention part 410 is determined according to the shape of the multiple soft magnetic material sheets (electromagnetic steel sheets in this embodiment) to be stacked. Also, the misalignment prevention part 410 is configured so that its mechanical strength is not reduced by contact with the electromagnetic steel sheet group 100.

[0102] FIG. 4B illustrates rod-shaped misalignment prevention portions 420a to 420c. FIG. 4B illustrates a case where the shape of the misalignment prevention portions 420a to 420c is a solid cylinder. The rod-shaped misalignment prevention portions 420a to 420c are arranged so that their side surfaces contact the side surfaces of the electromagnetic steel sheet group 100 (the multiple electromagnetic steel sheets 10 stacked in the stacking process). It is preferable that each of the side surfaces of the rod-shaped misalignment prevention portions 420a to 420c contacts a portion of the edge of the sheet surface of all of the electromagnetic steel sheets 10 stacked in the stacking process. In this case, the length in the stacking direction of the electromagnetic steel sheets may be the same for the rod-shaped misalignment prevention portions 420a to 420c and the multiple electromagnetic steel sheets 10 (the electromagnetic steel sheet group 100) stacked in the stacking process. In this case, the length of the rod-shaped anti-misalignment portions 420a to 420c in the stacking direction of the electromagnetic steel sheets may be longer than the multiple electromagnetic steel sheets 10 (electromagnetic steel sheet group 100) stacked in the stacking process.

[0103] 4B illustrates an example in which the number of rod-shaped misalignment prevention portions 420a to 420c is three, from the viewpoint of achieving both a further reduction in the possibility of misalignment of the electromagnetic steel sheet 10 in the sheet surface direction (the x-y plane direction in FIGS. 1 to 3 ) and a reduction in the number of misalignment prevention portions. However, the number of rod-shaped misalignment prevention portions may be four or more. Furthermore, for example, one or two rod-shaped misalignment prevention portions may be disposed in positions where misalignment in the sheet surface direction is expected to be likely. The shape of the rod-shaped misalignment prevention portions 420a to 420c is not limited to a solid cylinder, and may be, for example, a rectangular pillar shape. Furthermore, the misalignment prevention portions 420a to 420c are configured so that their mechanical strength is not reduced by contact with the electromagnetic steel sheet group 100.

[0104] 4A and 4B may be heated to a temperature equal to or higher than the temperature at which the adhesive ability of the bondable insulating coating is exerted, thereby allowing partial bonding of the areas of the sheet surface of the magnetic steel sheet 10 near the areas facing the displacement prevention parts 410, 420a to 420c.

[0105] (Other Embodiments) The above-described embodiments of the present invention are merely examples of specific embodiments for carrying out the present invention, and the technical scope of the present invention should not be construed as being limited by these. In other words, the present invention can be embodied in various forms without departing from its technical concept or main features.

[0106] The present invention can be used, for example, to manufacture laminated cores.

Claims

1. A method for manufacturing a laminated core using a plurality of soft magnetic plates, the soft magnetic plates having an insulating coating formed on the entire surface thereof, the insulating coating being capable of exerting adhesive properties when heated, comprising the steps of: a lamination step of laminating a plurality of the soft magnetic plates; a bonding step of bonding the soft magnetic plates laminated in the lamination step by exerting the adhesive ability; having In the bonding step, a heating unit is brought into contact with a portion of the plate surface of the outermost soft magnetic plate, thereby simultaneously applying pressure and heat to the portion, A method for manufacturing a laminated core, wherein the outermost soft magnetic plate is a soft magnetic plate located at one or both ends in the stacking direction among the multiple soft magnetic plates stacked in the stacking process.

2. In the bonding step, the heating unit is brought into contact with a plurality of regions of one plate surface of the outermost soft magnetic plate, The method for manufacturing a laminated core according to claim 1 , wherein two or more of the plurality of regions are located at positions spaced apart from each other.

3. The method for manufacturing a laminated core according to claim 2 , wherein in the bonding step, a plurality of the heating parts are simultaneously brought into contact with the plurality of regions, thereby simultaneously pressurizing and heating the regions in the plurality of regions.

4. 4. The method for manufacturing a laminated core according to claim 1, wherein in the bonding step, the heating portion is brought into contact with the region by moving the heating portion toward the soft magnetic plate.

5. The method for manufacturing a laminated core according to any one of claims 1 to 3, wherein the number of said soft magnetic plates bonded by one application of pressure and heat is three or more.

6. The method for manufacturing a laminated core according to any one of claims 1 to 3, wherein cutting of the soft magnetic plate is not performed simultaneously with the application of pressure and heat.

7. A laminated core manufacturing apparatus for manufacturing a laminated core using a plurality of soft magnetic plates, the plate surfaces of which are entirely covered with an insulating coating that exhibits adhesive properties when heated, comprising: a heating unit that heats the soft magnetic plate to exert the adhesive ability; a pressure treatment means for performing a treatment for applying pressure to the soft magnetic plate by bringing the heating unit into contact with the soft magnetic plate of the outermost layer; a heat treatment means for performing a process for heating the soft magnetic plate using the heating unit, the soft magnetic material plate of the outermost layer is a soft magnetic material plate located at one or both ends in a stacking direction among the plurality of stacked soft magnetic material plates, A laminated core manufacturing device which simultaneously pressurizes and heats a portion of a surface area of ​​the outermost soft magnetic plate by bringing the heating part into contact with the surface area of ​​the outermost soft magnetic plate using the pressure treatment means and heating the soft magnetic plate using the heating part using the heat treatment means.

8. The pressure treatment means brings the heating unit into contact with a plurality of regions of one plate surface of the outermost soft magnetic plate, The laminated core manufacturing apparatus according to claim 7 , wherein two or more of the plurality of regions are located at positions spaced apart from each other.

9. The heating unit is provided in a plurality of units. The laminated core manufacturing apparatus according to claim 8 , wherein the pressurizing means brings a plurality of the heating parts into contact with the plurality of regions simultaneously.

10. 10. The laminated core manufacturing device according to claim 7, wherein the pressure treatment means brings the heating part into contact with the region by moving the heating part toward the soft magnetic plate.

11. 10. The laminated core manufacturing apparatus according to claim 7, wherein the number of said soft magnetic plates bonded by one application of pressure and heat is three or more.

12. 10. The laminated core manufacturing apparatus according to claim 7, wherein cutting of the soft magnetic plate is not performed simultaneously with the application of pressure and heat.

13. A laminated core is formed by laminating a plurality of soft magnetic plates, the soft magnetic plates having an insulating coating that exhibits adhesive properties when heated and formed on the entire surface of the plate, The soft magnetic plates adjacent to each other in the lamination direction are bonded to each other in a partial region of the plate surface of the soft magnetic plate, the number of regions in one plate surface of the soft magnetic material plate bonded to a plate surface of an adjacent soft magnetic material plate in the stacking direction is 0.3×Nt or more and 6.0×Nt or less; The laminated core is a stator core or a rotor core, When the laminated core is a stator core, Nt is the number of teeth of the stator core, When the laminated core is a rotor core, Nt is the number of teeth of a stator core that pairs with the rotor core.

14. A laminated core having a plurality of soft magnetic plates, the soft magnetic plates having an insulating coating formed on the entire surface thereof, the insulating coating being capable of exerting adhesive properties when heated, The laminated core is a lamination step of laminating a plurality of the soft magnetic plates; a bonding step of bonding the soft magnetic plates laminated in the lamination step by exerting the adhesive ability; The method is produced by a process comprising: In the bonding step, a heating unit is brought into contact with a portion of the plate surface of the outermost soft magnetic plate, thereby simultaneously applying pressure and heat to the portion, A laminated core, wherein the soft magnetic plate of the outermost layer is a soft magnetic plate located at one or both ends in the stacking direction among the multiple soft magnetic plates stacked in the stacking step.

15. A rotating electric machine comprising the laminated core according to claim 13 or 14.