Core manufacturing method and device

Abstract

Provided is a core manufacturing method capable of preventing the lamination thickness of a motor core from being outside an allowable range. The lamination thicknesses of blocks B each of which is formed by laminating a plurality of sheet materials are measured and, after measuring the respective thicknesses, the plurality of blocks B are stored in a state in which each individual block B among the plurality of blocks B is identified. A combination having a predetermined lamination thickness is selected from among the stored plurality of blocks B, and the blocks B are laminated according to the selected combination.

Description

Core manufacturing method and apparatus

[0001] The present invention relates to a method and apparatus for manufacturing cores used in rotating electrical machines such as electric motors and generators.

[0002] Conventional core manufacturing methods include, for example, those disclosed in Patent Document 1, in which a plurality of plate-shaped core pieces punched out from a steel plate are laminated to form a laminated core as a core.

[0003] In this core manufacturing method, the thickness of the steel plate is measured at multiple measurement reference points, and core pieces punched out from the steel plate are then rotated and stacked (rolled) based on the measured thickness of the steel plate to minimize thickness deviation.

[0004] On the other hand, a core may be manufactured by stacking multiple core pieces to form a block, and then stacking multiple blocks together. In this case, by manufacturing each block using the core manufacturing method described in Patent Document 1, it is possible to minimize the deviation in thickness of each block. This allows the block thickness to be within the allowable range, such as tolerance.

[0005] However, even if the thickness of each block is within the allowable range, stacking multiple blocks adds up errors within the allowable range of tolerances, etc. As a result, there is a risk that the stack thickness, which is the thickness of multiple stacked blocks, will fall outside the allowable range of tolerances, etc.

[0006] Patent No. 6653619

[0007] The problem to be solved is that the thickness of the stacked blocks may be outside the allowable range.

[0008] The present invention provides a core manufacturing method that includes measuring the thickness of a block formed by stacking a plurality of plate materials, storing the plurality of blocks after measuring each thickness while identifying each individual block within the plurality of blocks, selecting a combination from the stored plurality of blocks that will result in a predetermined stack thickness, and stacking the blocks according to the selected combination.

[0009] The present invention also provides a core manufacturing device comprising a measuring unit that measures the thickness of a block formed by stacking a plurality of plate materials, a memory unit that stores identification information that identifies each block after the thickness has been measured, a storage unit that stores a plurality of blocks each having been identified, a selection unit that selects a combination from the stored plurality of blocks that results in a predetermined stack thickness, and a stacking unit that stacks the blocks according to the selected combination.

[0010] The present invention can prevent the stack thickness of the stacked blocks from falling outside the allowable range.

[0011] FIG. 1 is a conceptual diagram showing the process from forming to storing blocks in a core manufacturing apparatus according to a first embodiment of the present invention. FIG. 2 is a conceptual diagram showing the process from storing to stacking blocks in the core manufacturing apparatus according to the first embodiment. FIG. 3 is a flowchart showing the process from forming to storing blocks in a core manufacturing method according to the first embodiment. FIG. 4 is a flowchart showing the process from storing to stacking blocks in a core manufacturing method according to the first embodiment. FIG. 5 is a conceptual diagram showing the process from storing to stacking blocks in a core manufacturing apparatus according to a second embodiment of the present invention. FIG. 6 is a flowchart showing the process from storing to stacking blocks in a core manufacturing method according to the second embodiment. FIG. 7 is a conceptual diagram showing the process from storing to stacking blocks in a core manufacturing apparatus according to a third embodiment of the present invention. FIG. 8 is a conceptual diagram showing the forming and storing of blocks by multi-row punching in a core manufacturing method according to the third embodiment.

[0012] The core manufacturing method involves measuring the stack thickness of a block B made by stacking multiple plate materials P, storing the multiple blocks B after measuring their thickness while identifying each individual block B within the multiple blocks B, selecting a combination from the stored multiple blocks B that will result in a predetermined stack thickness, and stacking the blocks B according to the selected combination.

[0013] The blocks B can be identified by any suitable method. In one embodiment, an identifier 23 may be added to each block B to enable identification of each block B. In another embodiment, each block B may be identified by its storage location.

[0014] In one embodiment, the method for selecting a combination of blocks B can select all blocks B that result in a predetermined stack thickness.

[0015] In another embodiment, a first combination of blocks B that results in a stack thickness smaller than a predetermined stack thickness may be selected from the plurality of blocks B, and an intermediate IM may be formed by stacking the blocks B according to the selected first combination. In this case, the stack thickness of the intermediate IM may be measured, and a second combination of blocks B that, together with the intermediate IM, results in the predetermined stack thickness may be selected from the remaining blocks B of the plurality of blocks B, and one or more blocks B may be stacked on the intermediate IM according to the selected second combination.

[0016] The intermediate body IM may be formed of blocks B excluding the final block B for a predetermined stack thickness.

[0017] The stored blocks B may include blocks Ba and Bb of different shapes. In this case, a combination of blocks B that achieves a predetermined stack thickness includes two or more blocks Ba and Bb of different shapes.

[0018] In the case of different types of blocks Ba and Bb, blocks Ba (Bb) formed in the same row by punching a steel plate in multiple rows are of the same type, and the storage of blocks Ba and Bb may be performed for each block Ba (Bb) of the same type.

[0019] The plurality of blocks B stored may include both plus blocks B having a thickness greater than the reference thickness of blocks B and minus blocks B having a thickness less than the reference thickness.

[0020] The plus block B and the minus block B may be formed according to the trend of the measured thickness of the block B relative to the reference thickness.

[0021] The core manufacturing device 1 includes a measurement unit 3 , a memory unit 5 , a storage unit 7 , a selection unit 21 , and a stacking unit 9 .

[0022] The measuring unit 3 measures the thickness of the blocks B of the plurality of plate materials. The memory unit 5 stores identification information for identifying each block B after the thickness has been measured. The storage unit 7 stores the plurality of blocks B after each block B has been identified. The selection unit 21 selects a combination of blocks B from the plurality of stored blocks B that will result in a predetermined stack thickness. The stacking unit 9 stacks the blocks B according to the selected combination.

[0023] The core manufacturing device 1 may include an identifier adding unit 13 that adds an identifier 23 to each block B, which enables the individual block B to be identified. The identifier 23 constitutes readable identification information. The identification information may be the storage location of each block B.

[0024] The core manufacturing apparatus 1 may include a measuring unit 25 that measures the stack thickness of an intermediate IM having a stack thickness smaller than a predetermined stack thickness due to stacking of blocks B. In this case, the selecting unit 21 selects a combination of blocks B that results in the predetermined stack thickness for the intermediate IM, and the stacking unit 9 stacks one or more blocks B onto the intermediate IM according to the selected combination.

[0025] When the intermediate IM is formed of blocks B other than the final block B, the selection unit 21 selects the final block B for the intermediate IM.

[0026] [Core Manufacturing Apparatus] Fig. 1 is a conceptual diagram showing the process from block molding to storage of a core manufacturing apparatus according to Example 1 of the present invention. Fig. 2 is a conceptual diagram showing the process from storage of blocks to stacking of the core manufacturing apparatus according to Example 1. In the drawings, the X direction is the direction of the manufacturing flow, the Y direction is the direction perpendicular to the direction of the manufacturing flow, and the Z direction is the direction of gravity.

[0027] 1 and 2 manufactures cores C for rotating electrical machines by stacking a plurality of blocks B, each of which is made up of a plurality of stacked plate materials P. The rotating electrical machine is an electric motor, a generator, or the like, and the cores C are rotor cores or stator cores.

[0028] The core manufacturing apparatus 1 includes a measuring device 3 serving as a measuring unit, a server 5 serving as a storage unit, a storage unit 7, and a laminating machine 9 serving as a laminating unit. In addition, the core manufacturing apparatus 1 of this embodiment includes a block molding machine 11, an identifier adding machine 13, a laminating jig 15, readers 17 and 19, and a controller 21.

[0029] The controller 21 is a computer having a processor and memory, and controls each part of the core manufacturing apparatus 1. The controller 21 can be configured with a single computer or multiple computers. When the controller 21 is configured with multiple computers, for example, a computer can be provided for each part of the core manufacturing apparatus 1.

[0030] Hereinafter, each part of the core manufacturing device 1 will be described along the flow of manufacturing the core C.

[0031] As shown in FIG. 1 , the block forming machine 11 is a device that forms a block B. The block forming machine 11 has, for example, a punch and a die, and sequentially punches out a plurality of plate materials P (core pieces) while feeding a strip-shaped electromagnetic steel sheet. The plurality of plate materials P are stacked and integrated to form the block B. The plate materials P can be integrated by welding, caulking, adhesive bonding, etc. The block B is transferred from the block forming machine 11 to the identifier adding machine 13. This transfer can be performed by a transfer device such as a conveyor.

[0032] The identifier adder 13 is a device that adds an identifier 23 to each block B. Identification information such as an ID that enables identification of each block B is encoded in the identifier 23. In this embodiment, the identifier 23 is formed of a two-dimensional barcode.

[0033] The identifier adding machine 13 adds the identifier 23 to the top surface of each block B by, for example, engraving. Therefore, the identifier adding machine 13 can be configured as a well-known engraving machine, and can engrave the identifier 23 by, for example, laser irradiation, stamping, cutting, etc. Note that the identifier 23 may also be added to the block B by other appropriate methods, such as printing.

[0034] The identification information of the identifier 23 added to the block B is stored in the server 5 from the controller 21, for example, when the identifier 23 is added to the block B. The block B to which the identifier 23 has been added is transported from the identifier adding device 13 to the measuring device 3 by a transport device.

[0035] The measuring device 3 is a device for measuring the thickness of a block B formed by stacking a plurality of plate materials P. The thickness of the block B refers to the thickness of the block B in the stacking direction of the plate materials P. The measuring device 3 can be configured using a well-known thickness measuring device, and may be either a non-contact type or a contact type. The measured value of the thickness of the block B may be appropriately selected as needed, such as the maximum thickness value of the block B, the average value of multiple points, or the thickness at each of multiple points.

[0036] When the thickness is measured by the measuring device 3, the identifier 23 is read by the reader 17. By reading this identifier 23, the identification information of the block B and the measured thickness can be associated and stored in the server 5. Note that a well-known barcode reader may be used as the reader 17 in this embodiment, but an appropriate one can be adopted depending on the type of identifier 23. The block B whose thickness has been measured is transferred from the measuring device 3 to the storage unit 7 by a transfer device.

[0037] The identifier adding device 13 may be omitted. Alternatively, the identifier adding device 13 may be disposed downstream of the measuring device 3. In this case, the thickness of the block B measured by the measuring device 3 may be incorporated into the identifier 23 and added to the block B.

[0038] The server 5 is a computer having a processor and memory, and stores information on the thickness of the block B and the storage position described below in association with the identification information of the block B.

[0039] The storage unit 7 stores a plurality of identified blocks B. In this embodiment, the storage unit 7 is configured, for example, as a pallet. The storage positions of the plurality of blocks B on the storage unit 7 are specified.

[0040] In this embodiment, the storage position is specified by coordinates (address) on the storage unit 7. For example, a plurality of blocks B are arranged in three rows and five columns in the storage unit 7, and the storage position of the block B is specified by the row and column.

[0041] When a block B is stored in the storage unit 7, the reader 19 reads the identifier 23. By reading the identifier 23, it becomes possible to store in the server 5 the location information of the storage location of the block B in association with the identification information of the block B. Therefore, each of the multiple blocks B stored in the storage unit 7 is identified by the identification information and location information.

[0042] For example, when block B is transported by the transporter and reaches the storage unit 7, the identifier 23 of block B is positioned within the reading range of the reader 19 and is read. The block B whose identifier 23 has been read is placed in a storage position in the storage unit 7 in accordance with the operation of the transporter. In response to this, the controller 21 can identify the storage position of block B and transmits this storage position together with the identification information of the identifier 23 read by the reader 19 to the server 5.

[0043] The transfer of the block B to the storage unit 7 may be performed manually by an operator. In this case, the operator reads the identifier 23 of the block B at the storage position in the storage unit 7 that has been manually arranged, and inputs the storage position information to transmit it to the server 5.

[0044] The reader 19 in this embodiment may be a well-known barcode reader, similar to the reader 17, but an appropriate one may be adopted depending on the type of identifier 23. If the identifier adder 23 is omitted, the measured thickness of the block B and its storage position in the storage unit 7 may be stored in association with each other in the server 5. In this case, the storage position may be used as identification information for the block B. Therefore, each block B can be identified at least by its individual storage position.

[0045] The controller 21 as a selection unit selects a combination of blocks B that will result in a predetermined stack thickness from the multiple blocks B stored in the storage unit 7. That is, the controller 21 obtains the storage positions and thicknesses of the blocks B in the storage unit 7 from the server 5, and selects a combination of blocks B whose total thickness falls within the predetermined allowable range of stack thickness (tolerance as core C).

[0046] The stacker 9 stacks the blocks B in accordance with the combination selected by the controller 21. The stacker 9 is configured, for example, as a P&P machine (PICK-AND-PLACE machine).

[0047] When stacking the blocks B, the stacker 9 takes out the blocks B in accordance with the combination selected by the controller 21 based on the thickness of the blocks B and their storage positions in the storage section 7, and releases them onto the stacking jig 15.

[0048] As a result, the blocks B are stacked one after another in the stacking jig 15. Any appropriate stacking jig can be used as the stacking jig 15 as long as it can stack the blocks B. For example, the stacking jig 15 can be configured such that a columnar body is attached to a base, and the holes of the blocks B are fitted into the columnar body. The stacked multiple blocks B are integrated by welding, crimping, adhesive, etc. to form a core C. Note that the multiple blocks B may also be simply stacked to form the core C without being integrated.

[0049] If the storage unit 7 is taken offline (outside the production line), when a core C is subsequently formed using the blocks B on the storage unit 7, it is only necessary to read the identifiers 23 of two or more blocks B on the storage unit 7. This makes it possible to identify the storage positions of all blocks B on the storage unit 7. Furthermore, if the identifiers 23 are omitted, it is also possible to add identification information such as an identifier to the storage unit 7 and obtain the position information of the associated blocks B on the storage unit 7 by reading this information.

[0050] In the above configuration, the storage section 7 is configured by a pallet, but the storage section 7 can also be configured by using a conveyor or the like.

[0051] For example, the storage unit 7 may be configured by a pallet and part of a conveyor. In this case, some of the blocks B to be stacked may be removed from the conveyor by the stacker 9, and the remaining blocks B to be stacked may be removed from the pallet.

[0052] Alternatively, the storage unit 7 may be configured as a part of a conveyor without the pallet. In this case, the end of the conveyor may be looped to return the blocks B. When the blocks B are returned, the identifiers 23 may be read by a reader 19 or the like, and the order of the blocks B when returned may be determined as the storage position.

[0053] [Core Manufacturing Method] The core manufacturing method will be described below together with the operation of the core manufacturing device 1. Fig. 3 is a flowchart showing the steps from molding to storing of blocks in the core manufacturing method according to the first embodiment.

[0054] 3 , in the core manufacturing method of this embodiment, a block B is first formed (step S1). That is, a plurality of plate materials P are sequentially punched out while a strip-shaped electromagnetic steel sheet is fed by a block forming machine 11. The punched plurality of plate materials P are stacked and integrated into a block B.

[0055] The blocks B are transferred by a transfer device (not shown) to the identifier adder 13. The identifier adder 13 adds an identifier 23 to the blocks B (step S2). By adding the identifier 23 to each block B, each block B can be identified.

[0056] The block B with the identifier 23 attached thereto is transferred by a transfer device (not shown) to the measuring device 3. At this time, the reader 17 reads the identifier 23 of the block B (step S3). The measuring device 3 measures the thickness of the block B whose identifier 23 has been read (step S4).

[0057] When the thickness of block B is measured, the thickness is transmitted to the server 5 together with the identification information of the identifier 23 of block B. The server 5 stores the thickness in association with the identification information of block B (step S5).

[0058] The block B whose thickness has been measured is transferred to the storage unit 7 by a transfer device (not shown). At this time, the reader 19 reads the identifier 23 of the block B (step S6). In the storage unit 7, the block B whose identifier 23 has been read is stored (step S7).

[0059] At this time, the storage positions of the blocks B on the storage unit 7 are acquired through the operation of the transfer machine or the like. As a result, the storage unit 7 can store the multiple blocks B after measuring their thicknesses in a state in which each individual block B within the multiple blocks B is identified.

[0060] The storing operation of the block B on the storage unit 7 can also be performed by a robot arm or the like. For example, the robot arm picks up the block B from the transfer device and places the picked-up block B at a storage position on the storage unit 7. In this case, the storage position of the block B can be obtained through the operation of the robot arm or the like.

[0061] The storage position of the block B on the storage unit 7 is transmitted together with the identification information to the server 5. As a result, the server 5 stores the storage position together with the thickness in association with the identification information (step S8).

[0062] The blocks B are stored in the storage unit 7 (steps S6 to S8) until the number of stored blocks B reaches a predetermined number (step S9). When the predetermined number of blocks B have been stored in the storage unit 7, the blocks B are stacked.

[0063] FIG. 4 is a flowchart showing the steps from storing blocks to laminating blocks in the core manufacturing method according to the first embodiment.

[0064] The controller 21 as a selection unit selects a combination of blocks B that will result in a predetermined stack thickness from the plurality of stored blocks B based on information stored in the server 5. Specifically, the controller 21 acquires the storage positions and thicknesses of the blocks B on the storage unit 7 from the server 5 (step S10).

[0065] Then, the controller 21 selects a combination of blocks B that will result in a predetermined stack thickness based on the storage positions and thicknesses of the blocks B on the storage unit 7 (step S11).

[0066] The controller 21 outputs the storage positions of the blocks B of the selected combination to the stacker 9 (step S12). The stacker 9 removes the blocks B of the storage positions input from the controller 21 from the storage section 7 and releases them onto the stacking jig 15. In this way, the blocks B are stacked according to the selected combination (step S13).

[0067] For example, four blocks B are selected from the 15 blocks B on the storage section 7. The selected four blocks B are stacked as shown in FIG.

[0068] The stacked block B can have a stack thickness, which is the thickness of the stacked body, within a predetermined stack thickness or an allowable range thereof, and can be prevented from exceeding the allowable range.

[0069] These blocks B are integrated by welding or the like to form the core C. Therefore, the stack thickness of the core C, in which a plurality of blocks B are stacked, can be prevented from falling outside the allowable range.

[0070] When stacking the blocks B, the blocks B may be rotated to make the phases of adjacent blocks B different in the stacking direction.

[0071] In the case of rotating the blocks B, it is also possible to change the angle at which the blocks B are rotated (the rotating angle) depending on the circumferential thickness variation (deviation) within the blocks B. This reduces the circumferential thickness variation (deviation) of the core C. Note that the thickness of the blocks B may be measured and recorded at multiple points, and the rotation angle may be determined appropriately depending on the thickness information at the multiple points.

[0072] [Variant] The multiple blocks B arranged on the storage section 7 may include both one or more plus blocks B having a thickness greater than the standard thickness of each block B and one or more minus blocks B having a thickness less than the standard thickness.

[0073] The plus block B and the minus block B may be molded depending on the tendency of the measured thickness of the block B relative to the reference thickness. For example, if the measured thickness of the block B tends to exceed the reference thickness, the block molding machine 11 is caused to mold a minus block having a thickness below the reference thickness.

[0074] The thickness of the plus block B and the minus block B is set within the tolerance range for the reference thickness, but may be set within a range greater than the tolerance.

[0075] This configuration can avoid problems such as not finding a suitable combination to keep the stacking thickness of the core C within the allowable range. Also, there is no need to increase the size of the storage section 7 and the number of blocks B stored therein in order to increase the probability of finding a suitable combination.

[0076] Fig. 5 is a conceptual diagram showing the process from storing to stacking blocks of a core manufacturing apparatus according to Example 2 of the present invention. Fig. 6 is a flowchart showing the process from storing to stacking blocks of a core manufacturing method according to Example 2. Note that, since the basic configuration of Example 2 is the same as that of Example 1, the same reference numerals are used to denote components corresponding to those of Example 1, and redundant explanations will be omitted.

[0077] The core manufacturing apparatus 1 of Example 2 further includes a measuring device 25. The other configurations of Example 2 are the same as those of Example 1. The measuring device 25 measures the stack thickness of an intermediate body IM having a stack thickness smaller than a predetermined stack thickness. In this example, the intermediate body IM is formed of blocks B excluding the final block B for the predetermined stack thickness.

[0078] The controller 21, which serves as a selection unit, selects a first combination of blocks B from the plurality of blocks B, which results in a stack thickness smaller than a predetermined stack thickness, and the lamination machine 9 laminates the blocks B according to the selected first combination to form an intermediate body IM. The number of blocks B constituting the intermediate body IM is smaller than the number of blocks B constituting the core C.

[0079] The blocks B of the first combination can be selected arbitrarily. For example, when a core C is formed by stacking four layers of blocks B, three blocks B are randomly selected from the storage section 7 as the first combination. Alternatively, three of the four blocks B selected to achieve a predetermined stack thickness can be selected as the first combination. Note that the intermediate IM only needs to have a stack thickness smaller than the predetermined stack thickness, and the number of blocks B constituting the intermediate IM can be any number as long as it is smaller than the number of blocks B constituting the core C.

[0080] The core manufacturing method of Example 2 is basically the same as that of Example 1, except that after measuring the stack thickness of the intermediate body IM in which blocks B are stacked, a block B to be combined with the intermediate body IM is selected, and the selected block B is stacked on the intermediate body IM.

[0081] In the flowchart of FIG. 6, steps S22 to S28 are executed instead of steps S11 to S13 in the flowchart of FIG.

[0082] That is, the controller 21 as a selection unit acquires the storage position and thickness of the block B on the storage unit 7 from the server 5 (step S10), and selects the block B of the first combination (step S22).

[0083] Then, the controller 21 outputs the storage position of the selected first combination of blocks B to the stacker 9 (step S23). The stacker 9 removes the blocks B at the storage positions input from the controller 21 from the storage section 7 and releases them onto the stacking jig 15. In this way, the blocks B are stacked to form an intermediate IM (step S24).

[0084] The formed intermediate IM is transferred by a transfer machine (not shown) to the measuring machine 25. In the measuring machine 25, the laminate thickness of the intermediate IM is measured (step S25).

[0085] After measuring the stack thickness of the intermediate body IM, a second combination of blocks B that, together with the intermediate body IM, forms the predetermined stack thickness is selected from the remaining blocks B (step S26). That is, the controller 21 identifies the final block B in the storage unit 7, which has a thickness that is the difference between the stack thickness of the intermediate body IM and the predetermined stack thickness. The thickness of the block B identified at this time may be the same as the difference between the stack thickness of the intermediate body IM and the predetermined stack thickness, or may be within the tolerance of the core C.

[0086] The storage positions of the blocks B of the selected second combination are output to the stacker 9 (step S27). The stacker 9 removes the blocks B of the input storage positions from the storage section 7 and releases them onto the intermediate body IM of the stacking jig 15. As a result, one or more blocks B, in this embodiment, the selected one block B (in this embodiment, the block B in the final layer), are stacked on the intermediate body IM according to the selected second combination (step S28).

[0087] In Example 2, for an intermediate IM having a lamination thickness smaller than a predetermined lamination thickness, a block B to be combined with the intermediate IM is selected based on the lamination thickness of the intermediate IM. The selected block B is then laminated and integrated with the intermediate IM to obtain a core C. This allows the lamination thickness of the core C to be more accurately within the allowable range.

[0088] In addition, the second embodiment can also achieve the same effects as the first embodiment.

[0089] Fig. 7 is a conceptual diagram showing the process from storing to stacking blocks in a core manufacturing apparatus according to Example 3 of the present invention. Fig. 8 is a conceptual diagram showing the process from forming blocks by multi-row punching to storing in a core manufacturing method according to Example 3. Note that Example 3 has a basic configuration in common with Example 2, and components that are the same as or correspond to those in Example 2 are designated by the same reference numerals, and redundant explanations will be omitted.

[0090] In this embodiment, the stored blocks B include blocks Ba and Bb of different shapes. The stored blocks B include two types of blocks Ba and Bb, but may include three or more types of blocks.

[0091] The storage sections 7A and 7B store different types of blocks Ba and Bb, respectively. Therefore, a single storage section 7A (7B) stores the same type of blocks Ba (Bb). The different types of blocks Ba and Bb may have holes that are connected but misaligned.

[0092] When stacking the blocks B, different types of blocks Ba and Bb are mixed together. In other words, a combination of blocks that achieves a predetermined stack thickness includes two or more different types of blocks, in this embodiment, two types of blocks Ba and Bb. For example, the controller 21, which serves as a selection unit, selects blocks Ba and Bb from the storage units 7A and 7B, respectively. By stacking these selected blocks Ba and Bb, an intermediate IM is formed as shown in FIG. 7.

[0093] To stack the blocks Ba and Bb, stackers 9A and 9B are used for the storage sections 7A and 7B, respectively. The stackers 9A and 9B have the same configuration as the stacker 9 in the above embodiment.

[0094] Once the intermediate IM is formed, the thickness of the intermediate IM is measured in the same manner as in Example 3. After this measurement, a block Ba or Bb in the fourth, final layer is selected from the storage section 7A or 7B so as to achieve a predetermined stack thickness. In FIG. 7, block Ba is selected as the final layer. However, the ratio of blocks Ba and Bb to be selected is appropriately selected depending on the stacking pattern.

[0095] 8, it is also possible to punch multiple rows of blocks Ba (Bb) of the same type in a single strip-shaped electromagnetic steel sheet W. In this case, blocks Ba (Bb) of the same type are stored in storage section 7A (7B).

[0096] In the third embodiment, when a core C is manufactured by laminating different types of blocks Ba and Bb having different shapes, the lamination thickness of the core C can be more accurately set within the allowable range.

[0097] In addition, the third embodiment can also achieve the same effects as those of the second embodiment. Note that in this embodiment, it is also possible not to mold the intermediate body IM, as in the first embodiment.

[0098] REFERENCE SIGNS LIST 1 Core manufacturing device 3 Measuring machine 5 Memory unit (server) 7, 7A, 7B Storage unit 9, 9A, 9B Stacking unit 11 Block molding machine 13 Identifier adding machine (identifier adding unit) 15 Stacking jig 21 Controller (selection unit) 23 Identifier B Block

Claims

1. A core manufacturing method comprising: measuring the thickness of a block formed by stacking a plurality of plate materials; storing the plurality of blocks after measuring the thickness while identifying each individual block within the plurality of blocks; selecting a combination from the stored plurality of blocks that will result in a predetermined stack thickness; and stacking the blocks according to the selected combination.

2. A core manufacturing method according to claim 1, wherein an identifier is added to each of the blocks to enable identification of each of the blocks.

3. A core manufacturing method according to claim 1, wherein the individual blocks are identifiable by their individual storage positions.

4. A core manufacturing method according to claim 1, comprising the steps of: selecting a first combination of blocks from the plurality of blocks that will result in a stack thickness smaller than the predetermined stack thickness; forming an intermediate body by stacking the blocks in accordance with the selected first combination; measuring the stack thickness of the intermediate body; selecting a second combination of blocks from the remaining blocks of the plurality of blocks that, together with the intermediate body, will result in the predetermined stack thickness; and stacking one or more blocks on the intermediate body in accordance with the selected second combination.

5. A core manufacturing method according to claim 4, wherein the intermediate body is formed of blocks excluding the final block for the predetermined stack thickness.

6. A core manufacturing method according to claim 1, wherein the stored plurality of blocks include blocks of different types having different shapes, and the combination of blocks that achieves the specified stack thickness includes two or more of the different types of blocks.

7. A core manufacturing method according to claim 6, wherein, among the heterogeneous blocks, blocks formed in the same row by punching a steel plate in multiple rows are of the same type, and the storage is carried out for each of the same type of blocks.

8. A core manufacturing method according to any one of claims 1 to 7, wherein the plurality of blocks stored include both plus blocks having a thickness greater than the reference thickness of the blocks and minus blocks having a thickness less than the reference thickness.

9. A core manufacturing method according to claim 8, wherein the plus block and the minus block are formed according to the tendency of the measured thickness of the block relative to the reference thickness.

10. A core manufacturing device comprising: a measuring unit that measures the thickness of a block formed by stacking a plurality of plate materials; a memory unit that stores identification information that identifies each block after the thickness has been measured; a storage unit that stores a plurality of blocks each having been identified; a selection unit that selects a combination from the stored plurality of blocks that will result in a predetermined stack thickness; and a stacking unit that stacks the blocks according to the selected combination.

11. A core manufacturing apparatus according to claim 10, comprising an identifier adding section that adds an identifier to each of the blocks to enable each of the blocks to be identified.

12. A core manufacturing device according to claim 10, wherein the storage unit includes, as the identification information, the storage locations of the individual blocks.

13. A core manufacturing device according to claim 10, wherein the measuring unit measures the thickness of an intermediate body having a thickness smaller than the predetermined thickness by stacking the blocks, the selecting unit selects a combination of blocks that will result in the predetermined thickness for the intermediate body, and the stacking unit stacks one or more blocks on the intermediate body in accordance with the selected combination.

14. A core manufacturing apparatus according to claim 12, wherein the intermediate body is formed of blocks excluding a final block for the predetermined stack thickness, and the selection unit selects the final block for the intermediate body.

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