Apparatus for manufacturing laminated iron core

Abstract

To apply appropriate back pressure when forming an iron core member by punching out a metal plate, and to suppress thrusting of the iron core member mounted on a mounting table.SOLUTION: A manufacturing apparatus 10 comprises: a lower die 20; an upper die 40 having a contour punching punch 45 for forming an iron core member 5 by punching a strip-shaped metal plate W; a mounting table 30 that is provided so that it can be raised and lowered and on which the formed core members 5 are sequentially placed; a support member 32 that supports the mounting table 30 so that it can be raised and lowered; a lifting motor 36 that lifts and lowers the mounting table 30 through the support member 32; and a control device 90 that controls the upper die 40 and the lifting motor 36. The control device 90 includes a torque control unit 94 that changes the output torque of the lifting motor 36 from a first output torque to a second output torque higher than the first output torque after a lower surface 45B of the contour punching punch 45 passes through a midpoint between a top dead center and a bottom dead center and before the lower surface reaches the bottom dead center.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an apparatus for manufacturing a laminated core. [Background technology]

[0002] Laminated cores used in motors and the like are formed by punching a strip-shaped metal plate (e.g., strip-shaped steel plate) into a predetermined shape to form core members (cores), and stacking and integrating the formed core members. For example, laminated cores are formed by stacking and integrating core members by caulking, welding, adhesives, or the like. For example, Patent Document 1 discloses a manufacturing device that manufactures a laminated core by stacking a plurality of core members using an adhesive and bonding them together.

[0003] The manufacturing device of Patent Document 1 includes a receiving table on which the core members are sequentially placed, a lifting motor for raising and lowering the receiving table, and a control device for controlling the rotational operation of the lifting motor. In order to more effectively stack the laminated core, the torque limit value of the lifting motor is set to "high" when punching the core members, and an upward pressure (back pressure) is applied by the receiving table on which the laminated core members are sequentially stacked, and when the core members are not being punched, the torque limit value of the lifting motor is set to "low" to prevent the receiving table from pushing up the core members. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 5859715 Summary of the Invention [Problem to be solved by the invention]

[0005] However, if the timing of setting the output torque of the lifting motor is inappropriate, the following problems may occur. For example, if the torque limit value is set to "high" too early, the core material may be pushed up by the support base. If the torque limit value is set to "high" too late, sufficient back pressure may not be applied, and punching and lamination of the core material may not be performed properly.

[0006] The present invention has been made in consideration of these points, and its object is to provide a laminated core manufacturing apparatus that can apply an appropriate back pressure when punching a metal plate to form an iron core member, and can suppress the iron core member placed on a mounting table from being pushed up. [Means for solving the problem]

[0007] The laminated core manufacturing apparatus according to the present invention is an apparatus for manufacturing a laminated core in which a plurality of core members are stacked and bonded to one another, and includes a lower mold having a die with a die hole formed therein, an upper mold having a punch corresponding to the die hole and punching out a strip-shaped metal plate to form the core member, a mounting table that is provided so as to be able to rise and fall and on which the formed core members are successively placed, a support member that supports the mounting table so as to be able to rise and fall, a lifting motor that lifts and lowers the mounting table via the support member, and a scraper that is provided below the die and applies a lateral pressure to the core member placed on the mounting table. and a control device for controlling the upper die and the lifting motor, the control device having a torque control section that changes the output torque of the lifting motor from a first output torque to a second output torque higher than the first output torque, during the period from when the lower surface of the punch passes through a midpoint between top dead center and bottom dead center to when the lower surface of the punch reaches the bottom dead center, and the torque control section changes the output torque of the lifting motor from the first output torque to the second output torque, during the period from when the lower surface of the punch passes through the midpoint to before it comes into contact with the upper surface of the metal sheet.

[0008] According to the laminated core manufacturing device of the present invention, the torque control unit changes the output torque of the lifting motor from the first output torque to the second output torque after the bottom surface of the punch passes the midpoint and before it comes into contact with the top surface of the metal plate. According to the above aspect, the timing of the descent of the punch and the timing of the application of the second output torque can be synchronized, so that the core member placed on the mounting table can be prevented from jumping out of the squeeze ring and the product precision of the core member can be ensured. Furthermore, when punching the metal plate, the metal plate is sandwiched by the downward load from the punch and the upward back pressure from the mounting table, so that the flapping of the metal plate can be suppressed and the product precision of the core member can be further improved.

[0009] Another laminated core manufacturing apparatus according to the present invention is an apparatus for manufacturing a laminated core in which a plurality of core members are stacked and bonded to one another, comprising a lower mold having a die with a die hole formed therein, an upper mold having a punch that corresponds to the die hole and punches out a strip-shaped metal plate to form the core member, a mounting table that is arranged to be able to rise and fall and on which the formed core members are successively placed, a support member that supports the mounting table so that it can be raised and lowered, a lifting motor that raises and lowers the mounting table via the support member, a squeeze ring that is arranged below the die and applies lateral pressure to the core members placed on the mounting table, and and a control device that controls the upper die and the lifting motor, the control device having a torque control unit that changes the output torque of the lifting motor from a first output torque to a second output torque higher than the first output torque, during the period from when the lower surface of the punch passes the midpoint between the top dead center and the bottom dead center to when it reaches the bottom dead center, and the torque control unit changes the output torque of the lifting motor from the first output torque to the second output torque during the period from when the iron core member formed by punching out the metal plate begins to fall downward to when the lower surface of the punch reaches the bottom dead center.

[0010] According to another laminated core manufacturing device of the present invention, the torque control unit changes the output torque of the lifting motor from the first output torque to the second output torque during the period from when the core member formed by punching the metal plate starts to fall downward to when the lower surface of the punch reaches the bottom dead center. According to the above aspect, the timing of the punch's descent and the timing of applying the second output torque can be synchronized, so that the core member placed on the mounting table can be prevented from jumping out of the squeeze ring and the product precision of the core member can be ensured. Furthermore, since the output torque is changed to the second output torque after the metal plate is punched, back pressure can be applied from the mounting table to the core member formed by punching while it is in the squeeze ring, improving the lamination precision.

[0011] Another laminated core manufacturing apparatus according to the present invention is an apparatus for manufacturing a laminated core in which a number of core members are stacked and bonded to each other, and comprises a lower mold having a die with a die hole formed therein, an upper mold having a punch corresponding to the die hole and punching a strip-shaped metal plate to form the core member, a mounting table that is arranged to be able to be raised and lowered and on which the formed core members are successively placed, a support member that supports the mounting table so that it can be raised and lowered, a lifting motor that raises and lowers the mounting table via the support member, and a control device that controls the upper mold and the lifting motor, and the control device has a torque control unit that changes the output torque of the lifting motor from a second output torque higher than the first output torque to the first output torque while the lower surface of the punch moves from the bottom dead center to the midpoint between the bottom dead center and the top dead center.

[0012] According to another laminated core manufacturing device of the present invention, the torque control unit changes the output torque of the lifting motor from the second output torque to the first output torque during the time it takes for the lower surface of the punch to reach the midpoint from the bottom dead point. According to the above aspect, the torque control unit changes the output torque to the first output torque during the short time it takes for the lower surface of the punch to reach the midpoint from the bottom dead point, so that it is possible to apply an appropriate back pressure when punching the metal plate to form the core member, while suppressing the occurrence of thrust-up of the core member placed on the mounting table. Effect of the Invention

[0013] According to the present invention, it is possible to provide a laminated core manufacturing apparatus that can apply an appropriate back pressure when punching a metal plate to form an iron core member and can suppress the upward thrust of the iron core member placed on a mounting table. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a cross-sectional view showing a part of a manufacturing apparatus for a laminated core according to one embodiment. [Diagram 2] FIG. 2 is an example of a graph showing the relationship between the vertical position of the upper mold, the position of the mounting table, and the output torque of the lifting motor according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of a laminated core manufacturing apparatus according to the present invention will be described with reference to the drawings. Note that the embodiment described here is not intended to limit the present invention in any particular way. Also, the same reference numerals are used for members and parts that perform the same function, and duplicated descriptions are omitted or simplified as appropriate.

[0016] As shown in FIG. 1, a laminated core manufacturing apparatus 10 (hereinafter referred to as manufacturing apparatus 10) of this embodiment manufactures a laminated core 8 in which a plurality of core members 5 are stacked and bonded to each other. The manufacturing apparatus 10 is a progressive press die. In the manufacturing apparatus 10, a strip-shaped metal sheet W is intermittently conveyed in a progressive direction D. The strip-shaped metal sheet W is, for example, a coil material (strip-shaped thin steel sheet). The manufacturing apparatus 10 includes a lower die 20, an upper die 40, a pilot pin 50, a stripper plate 60, and a control device 90.

[0017] The lower die 20 is fixed to a floor surface. As shown in Fig. 1, the lower die 20 is provided with an outline punching stage 25. The outline punching stage 25 includes a die plate 22, a die 23, an outline punching die hole 26, a squeeze ring 27, and an outline punching punch 45, which will be described later. The outline punching die hole 26 is an example of a die hole. The outline punching punch 45 is an example of a punch.

[0018] The lower mold 20 has a lower mold body 21, a die plate 22, and a die 23. The die plate 22 and the die 23 are placed on the lower mold body 21. The die plate 22 holds the die 23. The die 23 includes an outer shape punching stage 25. A die hole 26 for punching the outer shape is formed in the die 23. An upper surface 22T of the die plate 22 and an upper surface 23T of the die 23 are located at the same height.

[0019] As shown in Fig. 1, squeeze ring 27 is disposed below die 23. Squeeze ring 27 holds formed core member 5 from the side. Squeeze ring 27 applies lateral pressure (i.e., clamping force) to stacked core members 5. Squeeze ring 27 holds core member 5 punched into outline punching die hole 26 by outline punching punch 45 (described later) with a predetermined lateral pressure.

[0020] The strip-shaped metal sheet W is intermittently transported to the lower die 20 by a transport device (not shown) provided near the manufacturing device 10. The strip-shaped metal sheet W is intermittently transported to the outline punching stage 25. The transport device holds the strip-shaped metal sheet W in a wound state. The strip-shaped metal sheet W is transported to the lower die 20 by an unwinding device (not shown) of the transport device, and the end material of the pressed strip-shaped metal sheet W is transported from the lower die 20 by a winding device (not shown) of the transport device and wound up on the winding device. Note that instead of the unwinding device and winding device of the transport device, the strip-shaped metal sheet W may be sandwiched between a pair of upper and lower rotating rolls arranged on the upstream and downstream sides of the manufacturing device 10, respectively, and transported.

[0021] As shown in Fig. 1, the manufacturing apparatus 10 includes a mounting table 30, a support member 32, and a lifting motor 36. The mounting table 30 is provided so as to be capable of rising and lowering. The formed core members 5 are sequentially placed on the mounting table 30. The mounting table 30 has a mounting surface 30F on which the core members 5 are placed. The mounting surface 30F may be located inwardly of the die 23 and the squeeze ring 27. The laminated core 8 is manufactured on the mounting surface 30F.

[0022] As shown in FIG. 1, the support member 32 supports the mounting table 30 so that it can be raised and lowered. The support member 32 includes a support shaft 33 and a ball screw 35. The support shaft 33 extends in the vertical direction Z. The upper end of the support shaft 33 is connected to the lower end of the mounting table 30. The support shaft 33 supports the mounting table 30. The lower end of the support shaft 33 is connected to a nut 35A of the ball screw 35, which will be described later. The ball screw 35 includes a nut 35A and a screw shaft 35B. The nut 35A is screwed into the screw shaft 35B. The screw shaft 35B is connected to a rotating shaft of the lifting motor 36. The lifting motor 36 rotates to rotate the screw shaft 35B, thereby lifting and lowering the nut 35A. This also lifts and lowers the mounting table 30.

[0023] As shown in FIG. 1, the lifting motor 36 lifts and lowers the mounting table 30 via the support member 32. Examples of the lifting motor 36 include a servo motor and a stepping motor. The lifting motor 36 is controlled by a control device 90. The lifting motor 36 is configured to be able to press upward the core member 5 placed on the mounting surface 30F via the support member 32 and the mounting table 30. This applies a back pressure to the core member 5. As described later, the core member 5 placed on the mounting table 30 can be applied with a back pressure caused by setting the output torque of the lifting motor 36 to a first output torque and a back pressure caused by setting the output torque of the lifting motor 36 to a second output torque. Note that the back pressure applied to the core member 5 by setting the output torque to the first output torque is smaller than the lateral pressure applied to the core member 5 by the squeeze ring 27. This makes it possible to suppress the thrust of the core member 5.

[0024] As shown in Fig. 1, the manufacturing apparatus 10 includes a sensor 38 that detects a load applied from the outer shape punching punch 45 to the mounting table 30 when the metal plate W is punched to form the iron core member 5. The sensor 38 is provided on the mounting table 30. The sensor 38 is connected to a control device 90. The sensor 38 is, for example, a pressure sensor. Note that the sensor 38 directly detects the load applied from the outer shape punching punch 45 to the mounting table 30, but the sensor may indirectly detect the load by another method.

[0025] As shown in FIG. 1, the upper die 40 is disposed above the lower die 20. The upper die 40 is configured to be able to rise and fall (to be able to move in the vertical direction Z). The upper die 40 is configured to be able to approach and move away from the lower die 20. The upper die 40 has an outline punch 45 corresponding to the outline punching die hole 26. The upper die 40 and the outline punching punch 45 rise and fall together. The outline punching punch 45 is located above the outline punching die hole 26. The outline punching punch 45 is configured to be able to pass through the outline punching die hole 26. In the outline punching stage 25, after the upper die 40 descends and approaches the lower die 20, the strip-shaped metal plate W is punched out by the outline punching punch 45 and the outline punching die hole 26. As a result, the outer shape of the core member 5 is formed on the band-shaped metal plate W to complete the core member 5, and the core members 5 are stacked one after another on the mounting table 30. When the band-shaped metal plate W is punched out, the output torque of the lifting motor 36 is changed to a second output torque as described below, and back pressure is applied to the core member 5. Here, the stacked core members 5 are joined to each other by crimping. For example, the laminated core 8 is formed by repeatedly joining the crimped portions (joint portions) formed on each of the two core members 5 stacked in the vertical direction Z to each other by crimping.

[0026] As shown in FIG. 1, the pilot pin 50 is provided on the upper die 40. The pilot pin 50 is configured to be movable in the up-down direction Z together with the upper die 40. The pilot pin 50 is configured to be insertable into a pilot hole PH formed in the metal plate W. The upper die 40 is lowered, whereby the pilot pin 50 is inserted into the pilot hole PH. The pilot pin 50 is inserted into the pilot hole PH, whereby the belt-shaped metal plate W is positioned relative to the manufacturing apparatus 10 (e.g., the mounting table 30).

[0027] As shown in FIG. 1, the stripper plate 60 is provided on the upper die 40. The stripper plate 60 is disposed at a position facing the die plate 22 of the lower die 20. The stripper plate 60 is configured to be movable in the vertical direction Z together with the upper die 40. The stripper plate 60 is configured to be movable downward to a lowest position (not shown) which is the lowest position. When the stripper plate 60 is punched out of the strip-shaped metal plate W by the outline punching punch 45, the stripper plate 60 restricts the metal plate W from moving in the vertical direction Z at the lowest position. When the stripper plate 60 moves to the lowest position, the stripper plate 60 is configured to press the intermittently conveyed strip-shaped metal plate W against the lower die 20 (here, the die plate 22 and the die 23) and to sandwich the strip-shaped metal plate W together with the lower die 20 (here, the die plate 22 and the die 23). The stripper plate 60 presses the strip-shaped metal plate W against the upper surface 22T of the die plate 22 and the upper surface 23T of the die 23. A punch insertion hole 60A through which the outer shape punching punch 45 is inserted is formed in the stripper plate 60. When the upper die 40 is further lowered in a state in which the stripper plate 60 presses the band-shaped metal sheet W against the die plate 22, the outer shape punching punch 45 protrudes from the punch insertion hole 60A and is inserted into the outer shape punching die hole 26.

[0028] 2 is an example of a graph showing the relationship between the vertical Z position of the upper die 40, the vertical Z position of the mounting table 30, and the output torque of the lifting motor 36 in one cycle from when the upper die 40, which is located at the top dead center, passes through the bottom dead center and returns to the top dead center again. The relationship between the vertical Z position of the upper die 40, the vertical Z position of the mounting table 30, and the output torque of the lifting motor 36 is not limited to that shown in FIG. 2. The vertical axis of FIG. 2 shows the vertical Z position of the upper die 40 and the vertical Z position of the mounting table 30, and the horizontal axis of FIG. 2 shows the angle (crank angle) of the upper die 40. In FIG. 1, the vertical Z position of the upper die 40 is shown by a solid line, the output torque of the lifting motor 36 is shown by a dashed line, and the vertical Z position of the mounting table 30 is shown by a dashed line.

[0029] As shown in FIG. 2, at timing T0 when the upper die 40 is located at the top dead center, the strip-shaped metal sheet W is being transported in the forward feed direction D (see FIG. 1). At this time, the output torque of the lifting motor 36 is set to a first output torque by a torque control unit 94 described later. When the upper die 40 moves downward and passes the midpoint between the top dead center and the bottom dead center at timing T1 and reaches timing T2, the transport of the strip-shaped metal sheet W is completed. That is, the transport of the strip-shaped metal sheet W is stopped from timing T2 to timing T12 described later. When the upper die 40 moves further downward and reaches timing T3, the pilot pin 50 starts to be inserted into the pilot hole PH formed in the metal sheet W. That is, the pilot pin 50 is not inserted into the pilot hole PH before timing T3. When the upper die 40 moves further downward and reaches timing T4, the stripper plate 60 comes into contact with the metal sheet W. When the upper die 40 moves further downward and reaches timing T5, the punch 45 for punching the outer shape starts punching the metal sheet W. That is, the lower surface 45B of the punch 45 for punching the outer shape comes into contact with the upper surface WT (see FIG. 1) of the metal sheet W. In the example shown in FIG. 2, the output torque of the lifting motor 36 is changed from the first output torque to the second output torque by the torque control unit 94 at a timing before timing T5. When the upper die 40 moves further downward and reaches timing T6, the iron core member 5 formed by punching the metal sheet W starts to fall downward. Then, at timing T7, the punched and fallen iron core member 5 comes into contact with the upper surface 5T of the iron core member 5 placed on the placement table 30. When the upper die 40 moves further downward and reaches timing T8, the punch 45 for punching the outer shape crimps the formed iron core member 5 and the stacked iron core members 5 to be joined to each other. Also, at timing T8, the upper die 40 is located at the bottom dead center. In the example shown in Fig. 2, at timing T8, the output torque of the lifting motor 36 is changed by the torque control unit 94 from the second output torque to the first output torque.Here, the torque control unit 94 holds the output torque of the lifting motor 36 at the second output torque from timing T5 to timing T8, and holds the output torque of the lifting motor 36 at the first output torque from timing T8 through timing T0 to timing T5. Then, the upper die 40 starts moving upward. When the upper die 40 moves upward from the bottom dead center and reaches timing T9, the punch 45 for punching the outer shape comes out of the punching hole WH (see FIG. 1) formed by punching the metal sheet W. That is, the punch 45 for punching the outer shape keeps a penetrating state with respect to the punching hole WH from timing T5 to timing T9 in FIG. 2. When the upper die 40 moves further upward and reaches timing T10, the pressing of the metal sheet W by the stripper plate 60 is completed. When the upper die 40 moves further upward and reaches timing T11, the pilot pin 50 inserted in the pilot hole PH comes out completely from the pilot hole PH. Between timing T3 and timing T11, at least a part of the pilot pin 50 is inserted into the pilot hole PH. When the upper die 40 moves further upward and reaches timing T12, the conveyance of the strip-shaped metal sheet W starts. That is, between timing T12 and timing T0, the strip-shaped metal sheet W is conveyed in the forward feed direction D. Then, the upper die 40 moves upward, passes the midpoint at timing T13, and reaches the top dead center at timing T0. In this way, the upper die 40 repeatedly descends and ascends (i.e., the punch 45 for punching the outer shape repeatedly descends and ascends), thereby manufacturing a laminated laminated core 8 having a preset thickness. When the laminated core 8 is manufactured, the lifting motor 36 is driven to lower the mounting table 30, and then the laminated core 8 is discharged from the manufacturing device 10 to the outside by a pusher (not shown). When the upper die 40 is positioned at the top dead point, the lower surface 45B of the punch 45 for punching out the contour is positioned at the top dead point, when the upper die 40 is positioned at the midpoint, the lower surface 45B of the punch 45 for punching out the contour is positioned at the midpoint, and when the upper die 40 is positioned at the bottom dead point, the lower surface 45B of the punch 45 for punching out the contour is positioned at the bottom dead point.

[0030] As shown in FIG. 1, the control device 90 controls the upper mold 40 and the lifting motor 36. The control device 90 includes, for example, a central processing unit (CPU) that executes instructions of a control program, a ROM that stores the program executed by the CPU, a RAM used as a working area for expanding the program, and a storage device such as a memory that stores the program and various data. The control device 90 includes an upper mold control unit 92 and a torque control unit 94. The functions of each unit of the control device 90 are realized by a program. This program is downloaded, for example, via the Internet. The program may be read from a recording medium such as a CD or DVD. The functions of each unit of the control device 90 may be realized by a processor and / or a circuit.

[0031] The upper die control unit 92 controls the upward and downward movement (movement in the vertical direction Z) of the upper die 40. In this embodiment, the upper die control unit 92 controls the upward and downward movement (rising and descending) of the punch 45 for punching an outline and the stripper plate 60 by moving the upper die 40 in the vertical direction Z. The upper die control unit 92 controls the approach of the upper die 40 to the lower die 20 and the separation of the upper die 40 from the lower die 20. The upper die control unit 92 controls the downward and upward movement of the punch 45 for punching an outline so that the punch 45 for punching an outline maintains a penetrating state with respect to the punching hole WH formed by punching the metal plate W with the punch 45 for a period from when the punch 45 for punching an outline punches the metal plate W to when the output torque of the motor for lifting and lowering is changed from the second output torque to the first output torque (for example, timing T6 to timing T8 or timing T6 to timing T9 in FIG. 2). The upper die control unit 92 controls the vertical movement of the stripper plate 60 so as to restrict the movement of the metal plate W in the vertical direction Z during at least a portion of the period (e.g., timing T6 to timing T9 in Figure 2) during which the contour punching punch 45 maintains a penetrating state through the punching hole WH formed by punching the metal plate W with the contour punching punch 45.

[0032] The torque control unit 94 controls the lifting motor 36. The torque control unit 94 controls the lifting motor 36 to move up and down (movement in the vertical direction Z) of the mounting table 30. The torque control unit 94 controls the output torque of the lifting motor 36. The torque control unit 94 is provided to be able to change the output torque of the lifting motor 36. The back pressure applied to the iron core member 5 is changed by changing the output torque. The torque control unit 94 sets the output torque of the lifting motor 36 to a first output torque so as to suppress the pushing up of the iron core member 5 by the mounting table 30 when the metal plate W is not punched out by the outer shape punching punch 45. The torque control unit 94 sets the output torque of the lifting motor 36 to a second output torque higher than the first output torque so as to apply a back pressure to the iron core member 5 by the mounting table 30 when the metal plate W is punched out by the outer shape punching punch 45 to form the iron core member 5. The first output torque and the second output torque are output torques of the lifting motor 36 during the punching process (when the metal plate W is punched to form the iron core member 5, for example, when the upper die 40 is moving up and down). In other words, the output torque of the lifting motor 36 when the laminated iron core 8 formed on the mounting table 30 is carried out to the outside of the manufacturing apparatus 10 or when the mounting table 30 is moved to the initial position is not included in the first output torque and the second output torque.

[0033] The torque control unit 94 may be configured to be able to change the first output torque. The torque control unit 94 may be configured to be able to hold the first output torque constant. That is, the torque control unit 94 may be configured to be unable to change the first output torque. The torque control unit 94 may be configured to be able to change the second output torque. For example, the amount of change in the second output torque is greater than the amount of change in the first output torque. The torque control unit 94 may be configured to be able to change the difference between the first output torque and the second output torque.

[0034] The torque control unit 94 may be configured to be able to change the first output torque in accordance with the load applied to the mounting table 30 from the outline punching punch 45 when punching the metal plate W to form the iron core member 5. The torque control unit 94 may be configured to lower the first output torque as the load applied to the mounting table 30 from the outline punching punch 45 when punching the metal plate W to form the iron core member 5 becomes smaller.

[0035] Torque control unit 94 may be configured to be able to change the first output torque depending on the thickness of iron core member 5. Torque control unit 94 may be configured to reduce the first output torque as the thickness of iron core member 5 becomes thinner.

[0036] Torque control unit 94 may be configured to be able to change the first output torque depending on the outer diameter of iron core member 5. Torque control unit 94 may be configured to reduce the first output torque as the outer diameter of iron core member 5 becomes smaller.

[0037] The torque control unit 94 may be configured to be able to change the first output torque according to the number of crimped portions when crimping one core member 5. Crimping one core member 5 means stacking and crimping a core member 5 formed by punching a metal plate W on top of an iron core member 5 already placed on the mounting table 30. The torque control unit 94 may be configured to lower the first output torque as the number of crimped portions decreases.

[0038] Torque control unit 94 may be configured to be able to change the first output torque in accordance with the lateral pressure applied to core member 5 by squeeze ring 27. Torque control unit 94 may be configured to reduce the first output torque as the lateral pressure becomes smaller.

[0039] Torque control unit 94 may be configured to be able to change the first output torque according to warping of iron core member 5 caused by lateral pressure applied to iron core member 5 by squeeze ring 27. Torque control unit 94 may be configured to reduce the first output torque as the warping of iron core member 5 becomes smaller.

[0040] The torque control unit 94 may be configured to be able to change the first output torque according to the shear resistance of the metal sheet W when the metal sheet W is punched by the outline punching punch 45. The torque control unit 94 may be configured to lower the first output torque as the shear resistance of the metal sheet W becomes smaller.

[0041] Torque control unit 94 may be configured to be able to change the first output torque in accordance with the weight per sheet of iron core member 5. Torque control unit 94 may be configured to reduce the first output torque as the weight per sheet of iron core member 5 becomes lighter.

[0042] The torque control unit 94 may be configured to be able to change the second output torque in accordance with the load applied to the mounting table 30 from the outline punching punch 45 when punching the metal plate W to form the iron core member 5. The torque control unit 94 may be configured to increase the second output torque as the load applied to the mounting table 30 from the outline punching punch 45 when punching the metal plate W to form the iron core member 5 increases.

[0043] The torque control unit 94 may be configured to change the second output torque based on the load detected by the sensor 38. The torque control unit 94 may be configured to change the second output torque based on the load detected by the punch 45 before the lower surface 45B of the punch 45 comes into contact with the upper surface WT of the metal plate W (for example, before timing T5 in FIG. 2). That is, the torque control unit 94 may be configured to change the second output torque of the iron core member 5 to be formed later based on the load when the iron core member 5 was previously formed before the metal plate W is punched out to form the iron core member 5. The torque control unit 94 may be configured to change the second output torque based on the load detected by the sensor 38 while the metal plate W is being punched out by the punch 45 (for example, timing T5 to timing T6 in FIG. 2). That is, the torque control unit 94 may be configured to change the second output torque of the iron core member 5 to be formed later based on the load when the iron core member 5 was previously formed while the metal plate W is being punched out.

[0044] Torque control unit 94 may be configured to be able to change the second output torque depending on the thickness of iron core member 5. Torque control unit 94 may be configured to increase the second output torque as the thickness of iron core member 5 increases.

[0045] Torque control unit 94 may be configured to be able to change the second output torque depending on the outer diameter of iron core member 5. Torque control unit 94 may be configured to increase the second output torque as the outer diameter of iron core member 5 increases.

[0046] Torque control unit 94 may be configured to be able to change the second output torque according to the number of crimped portions when crimping one iron core member 5. Torque control unit 94 may be configured to increase the second output torque as the number of crimped portions increases.

[0047] Torque control unit 94 may be configured to be able to change the second output torque in accordance with the lateral pressure applied to iron core member 5 by squeeze ring 27. Torque control unit 94 may be configured to increase the second output torque as the lateral pressure increases.

[0048] Torque control unit 94 may be configured to be able to change the second output torque according to warping of iron core member 5 caused by lateral pressure applied to iron core member 5 by squeeze ring 27. Torque control unit 94 may be configured to increase the second output torque as the warping of iron core member 5 increases.

[0049] The torque control unit 94 may be configured to be able to change the second output torque according to the shear resistance of the metal sheet W when the metal sheet W is punched by the outline punching punch 45. The torque control unit 94 may be configured to increase the second output torque as the shear resistance of the metal sheet W increases.

[0050] The torque control unit 94 changes the output torque of the lift motor 36 from the first output torque to the second output torque. The torque control unit 94 holds the output torque of the lift motor 36 at the second output torque for a predetermined time. In the example shown in Fig. 2, the torque control unit 94 holds the output torque of the lift motor 36 at the second output torque from timing T5 to timing T8.

[0051] The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the lower surface 45B (see FIG. 1) of the punch for punching an outline of the outer shape passes through the midpoint between the top dead point and the bottom dead point to when the lower surface 45B reaches the bottom dead point (for example, from timing T1 to timing T8 in FIG. 2). The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the lower surface 45B of the punch for punching an outline of the outer shape passes through the midpoint to when the lower surface 45B of the punch for punching an outline of the outer shape comes into contact with the upper surface WB of the metal sheet W (for example, from timing T1 to timing T5 in FIG. 2). The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque when the lower surface 45B of the punch for punching an outline of the outer shape comes into contact with the upper surface WB of the metal sheet W (for example, at timing T5 in FIG. 2). The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during a period from when the lower surface 45B of the punch 45 for punching an outline passes the midpoint until when the lower surface 45B of the punch 45 for punching an outline comes into contact with the upper surface WB of the metal sheet W (for example, after timing T1 and before timing T5 in FIG. 2, or after timing T4 and before timing T5). The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque before when the lower surface 45B of the punch 45 for punching an outline comes into contact with the upper surface WB of the metal sheet W (for example, before timing T5 in FIG. 2). The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during a period from when the stripper plate 60 comes into contact with the upper surface WT of the metal sheet W until when the lower surface 45B of the punch 45 reaches the bottom dead center (for example, from timing T4 to timing T8 in FIG. 2). The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the lower surface 45B of the punch 45 comes into contact with the upper surface WT of the metal plate W until when the core member 5 formed by punching out the metal plate W abuts against the upper surface 5T of the core member 5 placed on the mounting table 30 (for example, from timing T4 to timing T7 in Figure 2).The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the iron core member 5 formed by punching out the metal plate W starts to fall downward until the lower surface 45B of the punch 45 reaches the bottom dead center (for example, from timing T6 to timing T8 in FIG. 2). The torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the iron core member 5 formed by punching out the metal plate W starts to fall downward until the formed iron core member 5 comes into contact with the upper surface 5T of the iron core member 5 placed on the placement table 30 (for example, from timing T6 to timing T7 in FIG. 2). The torque control unit 94 may change the output torque of the lift motor 36 from the first output torque to the second output torque during the period from when the core member 5 formed by punching the metal plate W comes into contact with the upper surface 5T of the core member 5 placed on the placement table 30 until the lower surface 45B of the punch 45 reaches the bottom dead center (for example, from timing T7 to timing T8 in FIG. 2). When changing the output torque of the lift motor 36, a signal for changing the output torque is transmitted from the control device 90 to the lift motor 36. Here, "changing the output torque of the lift motor 36" includes a case where a signal for changing the output torque is transmitted from the control device 90 to the lift motor 36 before the timing for changing the output torque of the lift motor 36, and the change in the output torque is completed at the timing for changing the output torque of the lift motor 36, and a case where a signal for changing the output torque is transmitted from the control device 90 to the lift motor 36 before the timing for changing the output torque of the lift motor 36, and the change in the output torque continues at the timing for changing the output torque of the lift motor 36.

[0052] The timing at which the torque control unit 94 changes the output torque of the lifting motor 36 from the first output torque to the second output torque may be the same in an n-th punching process in which the metal plate W is punched by the outline punch 45 to form the n-th (n is a natural number) iron core member 5, and in an (n+1)-th punching process in which the metal plate W is punched by the outline punch 45 to form the (n+1)th iron core member 5. For example, the timing at which the output torque is changed may be the same in the first punching process and the second punching process.

[0053] The torque control unit 94 may be configured to be able to change the timing at which the output torque of the lift motor 36 is changed from the first output torque to the second output torque. The torque control unit 94 may be configured to make the timing at which the output torque of the lift motor 36 is changed from the first output torque to the second output torque earlier as the second output torque is higher. The torque control unit 94 may be configured to make the timing at which the output torque of the lift motor 36 is changed from the first output torque to the second output torque earlier as the difference between the first output torque and the second output torque is larger. The torque control unit 94 may be configured to make the timing at which the output torque of the lift motor 36 is changed from the first output torque to the second output torque earlier as the thickness of the metal plate W is greater.

[0054] The torque control unit 94 changes the output torque of the lift motor 36 from the first output torque to the second output torque in a rectangular wave shape (see FIG. 2). The torque control unit 94 may gradually change the output torque of the lift motor 36 from the first output torque to the second output torque. The torque control unit 94 may change the output torque of the lift motor 36 from the first output torque to the second output torque in a trapezoidal wave shape, a sine wave shape, a triangular wave shape, or a sawtooth wave shape.

[0055] The torque control unit 94 changes the output torque of the lift motor 36 from the second output torque to the first output torque. The torque control unit 94 holds the output torque of the lift motor 36 at the first output torque for a predetermined time. In the example shown in Fig. 2, the torque control unit 94 holds the output torque of the lift motor 36 at the first output torque from time T8 through time T0 to time T5.

[0056] The torque control unit 94 may change the output torque of the lifting motor 36 from the second output torque to the first output torque during the period from the bottom dead point until the bottom surface 45B (see FIG. 1) of the outer shape punching punch 45 reaches the midpoint (for example, timing T8 to timing T13 in FIG. 2). The torque control unit 94 may change the output torque of the lifting motor 36 from the second output torque to the first output torque when the bottom surface 45B (see FIG. 1) of the outer shape punching punch 45 starts to rise from the bottom dead point (for example, timing T8 in FIG. 2).

[0057] The timing at which the torque control unit 94 changes the output torque of the lifting motor 36 from the second output torque to the first output torque may be the same in an n-th punching process in which the metal plate W is punched by the outline punch 45 to form the n-th (n is a natural number) iron core member 5, and in an (n+1)-th punching process in which the metal plate W is punched by the outline punch 45 to form the (n+1)th iron core member 5. For example, the timing at which the output torque is changed may be the same in the first punching process and the second punching process.

[0058] The torque control unit 94 may be configured to be able to change the timing at which the output torque of the lift motor 36 is changed from the second output torque to the first output torque. The torque control unit 94 may be configured to delay the timing at which the change of the output torque of the lift motor 36 from the second output torque to the first output torque is completed as the first output torque is lower. The torque control unit 94 may be configured to delay the timing at which the change of the output torque of the lift motor 36 from the second output torque to the first output torque is completed as the difference between the first output torque and the second output torque is larger.

[0059] The torque control unit 94 changes the output torque of the lift motor 36 from the second output torque to the first output torque in a rectangular wave shape (see FIG. 2). The torque control unit 94 may gradually change the output torque of the lift motor 36 from the second output torque to the first output torque. The torque control unit 94 may change the output torque of the lift motor 36 from the second output torque to the first output torque in a trapezoidal wave shape, a sine wave shape, a triangular wave shape, or a sawtooth wave shape.

[0060] As described above, according to the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the lower surface 45B of the punch 45 for punching out the outline passes the midpoint to when it reaches the bottom dead point. According to the above aspect, the torque control unit 94 changes the output torque to the second output torque during the short period from when the lower surface 45B of the punch 45 for punching out the outline passes the midpoint to when it reaches the bottom dead point, so that it is possible to apply an appropriate back pressure when punching out the metal plate W to form the core member 5 while suppressing the occurrence of thrust-up of the core member 5 placed on the mounting table 30.

[0061] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the lower surface 45B of the outline punching punch 45 passes the midpoint until it comes into contact with the upper surface WT of the metal plate W. According to the above aspect, it is possible to apply back pressure at a more appropriate timing when punching the metal plate W to form the iron core member 5.

[0062] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque when the lower surface 45B of the outline punching punch 45 comes into contact with the upper surface WT of the metal plate W. According to the above aspect, it is possible to apply back pressure at a more appropriate timing when punching the metal plate W to form the iron core member 5.

[0063] In the laminated core manufacturing apparatus 10 of this embodiment, the output torque of the lifting motor 36 may be changed from the first output torque to the second output torque during the period from when the lower surface 45B of the punch 45 for punching the outer shape passes the midpoint until when the lower surface 45B comes into contact with the upper surface WB of the metal plate W. The timing of the descent of the punch 45 for punching the outer shape and the timing of the application of the second output torque can be synchronized, so that the core member 5 placed on the mounting table 30 can be prevented from jumping out of the squeeze ring 27 and the product precision of the core member 5 can be ensured. Furthermore, when the metal plate W is punched, the metal plate W is sandwiched by the downward load from the punch 45 for punching the outer shape and the upward back pressure from the mounting table 30, so that the fluttering of the metal plate W can be suppressed and the product precision of the core member 5 can be further improved.

[0064] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the stripper plate 60 comes into contact with the upper surface WT of the metal sheet W to when the lower surface 45B of the punch 45 reaches the bottom dead center. According to the above-described embodiment, it is possible to apply back pressure at a more appropriate timing when punching the metal sheet W to form the iron core member 5.

[0065] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the lower surface 45B of the punch 45 comes into contact with the upper surface WT of the metal plate W until the core member 5 formed by punching out the metal plate W comes into contact with the upper surface 5T of the core member 5 placed on the mounting table 30. According to the above aspect, it is possible to apply back pressure at a more appropriate timing when punching out the metal plate W and stacking the core members 5.

[0066] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the core member 5 formed by punching the metal sheet W starts to fall downward to when the lower surface 45B of the punch 45 reaches the bottom dead center. According to the above-mentioned aspect, it is possible to apply back pressure at a more appropriate timing when the core member 5 is formed by punching the metal sheet W.

[0067] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the core member 5 formed by punching out the metal plate W starts to fall downward until the formed core member 5 comes into contact with the upper surface 5T of the core member 5 placed on the mounting table 30. According to the above aspect, it is possible to apply back pressure at a more appropriate timing when punching out the metal plate W and stacking the core members 5.

[0068] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque during the period from when the core member 5 formed by punching out the metal plate W comes into contact with the upper surface 5T of the core member 5 placed on the mounting table 30 until the lower surface 45B of the punch 45 reaches the bottom dead center. According to the above aspect, it is possible to apply back pressure at a more appropriate timing when punching out the metal plate W to laminate the core members 5.

[0069] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the first output torque to the second output torque in a rectangular wave shape. According to the above aspect, the change to the second output torque is instantaneous, so that an appropriate back pressure can be applied while suppressing the thrust of the core member 5.

[0070] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may gradually change the output torque of the lifting motor 36 from the first output torque to the second output torque. According to the above aspect, even if the timing of applying back pressure to the core material 5 is slightly off, it is possible to suppress the thrust-up of the core material 5.

[0071] In the laminated core manufacturing apparatus 10 of the present embodiment, the timing at which the torque control unit 94 changes the output torque of the lifting motor 36 from the first output torque to the second output torque may be the same in the first punching process in which the metal plate W is punched by the outline punch 45 to form the first core member 5, and the second punching process in which the metal plate W is punched by the outline punch 45 to form the second core member 5. According to the above aspect, the lifting motor 36 can be easily controlled.

[0072] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may be configured to be able to change the second output torque. According to the above aspect, the second output torque can be appropriately set depending on the metal plate W and the core member 5 to be formed, so that an appropriate back pressure can be applied when the metal plate W is punched out to form the core member 5.

[0073] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may be configured to increase the second output torque as the load applied to the mounting table 30 from the outline punching punch 45 when punching the metal plate W to form the core member 5 increases. According to the above aspect, an appropriate back pressure can be applied when punching the metal plate W to form the core member 5.

[0074] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may be configured to be able to change the timing at which the output torque of the lifting motor 36 is changed from the first output torque to the second output torque. According to the above aspect, the timing at which the output torque is changed can be appropriately set depending on the metal sheet W and the core member 5 to be formed, so that an appropriate back pressure can be applied when punching out the metal sheet W to form the core member 5 while suppressing the occurrence of push-up of the core member 5 placed on the mounting table 30.

[0075] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may be configured to be able to change the second output torque, and to advance the timing at which the output torque of the lifting motor 36 is changed from the first output torque to the second output torque as the second output torque becomes higher. According to the above aspect, an appropriate back pressure can be applied more quickly when the metal plate W is punched to form the core member 5.

[0076] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may be configured to be able to change at least one of the first output torque and the second output torque, and may be configured to advance the timing at which the output torque of the lifting motor 36 is changed from the first output torque to the second output torque as the difference between the first output torque and the second output torque increases. According to the above aspect, an appropriate back pressure can be applied more quickly when the metal plate W is punched to form the iron core member 5.

[0077] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may be configured to advance the timing at which the output torque of the lifting motor 36 is changed from the first output torque to the second output torque as the thickness of the metal plate W increases. According to the above aspect, since the time for applying back pressure needs to be longer as the thickness of the metal plate W increases, an appropriate back pressure can be applied when the metal plate W is punched to form the iron core member 5 by accelerating the timing at which the output torque is changed to the second output torque.

[0078] Furthermore, according to the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 changes the output torque of the lifting motor 36 from the second output torque to the first output torque during the time it takes for the lower surface 45B of the outline punching punch 45 to reach the midpoint from the bottom dead point. According to the above aspect, the torque control unit 94 changes the output torque to the first output torque during the short time it takes for the lower surface 45B of the outline punching punch 45 to reach the midpoint from the bottom dead point, so that it is possible to suppress the occurrence of thrusting of the core member 5 placed on the placement table 30 while applying an appropriate back pressure when punching the metal sheet W to form the core member 5.

[0079] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the second output torque to the first output torque when the lower surface 45B of the outline punching punch 45 starts to rise from the bottom dead center. According to the above embodiment, the occurrence of push-up of the core member 5 placed on the mounting table 30 can be more reliably suppressed.

[0080] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may change the output torque of the lifting motor 36 from the second output torque to the first output torque in a rectangular wave shape. According to the above aspect, the change to the first output torque is instantaneous, so that it is possible to suppress the thrust-up of the core material 5 while applying an appropriate back pressure.

[0081] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may gradually change the output torque of the lift motor 36 from the second output torque to the first output torque. According to the above aspect, the operating load of the lift motor 36 can be reduced.

[0082] In the laminated core manufacturing apparatus 10 of the present embodiment, the timing at which the torque control unit 94 changes the output torque of the lifting motor 36 from the second output torque to the first output torque is the same in the first punching process in which the metal plate W is punched by the outline punch 45 to form the first core member 5, and the second punching process in which the metal plate W is punched by the outline punch 45 to form the second core member 5. According to the above aspect, the lifting motor 36 can be easily controlled.

[0083] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may be configured to be able to change the first output torque. According to the above aspect, the first output torque can be appropriately set, so that the thrust-up of the core member 5 can be more reliably suppressed.

[0084] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may be configured to lower the first output torque as the lateral pressure applied from the squeeze ring 27 to the core member 5 becomes smaller. According to the above aspect, the first output torque can be appropriately set, so that the thrust-up of the core member 5 can be more reliably suppressed.

[0085] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may be configured to be able to change the timing at which the output torque of the lifting motor 36 is changed from the second output torque to the first output torque. According to the above aspect, the timing at which the output torque is changed can be appropriately set depending on the metal sheet W and the core member 5 to be formed, so that it is possible to apply an appropriate back pressure when punching out the metal sheet W to form the core member 5, while suppressing the occurrence of push-up of the core member 5 placed on the mounting table 30.

[0086] In the laminated core manufacturing apparatus 10 of the present embodiment, the torque control unit 94 may be configured to be able to change the first output torque, and to delay the timing at which the output torque of the lifting motor 36 is changed from the second output torque to the first output torque as the first output torque becomes lower. According to the above aspect, an appropriate back pressure can be applied for an appropriate period of time when the metal plate W is punched to form the iron core member 5.

[0087] In the laminated core manufacturing apparatus 10 of this embodiment, the torque control unit 94 may be configured to be able to change at least one of the first output torque and the second output torque, and may be configured to delay the timing at which the output torque of the lifting motor 36 is changed from the second output torque to the first output torque as the difference between the first output torque and the second output torque increases. According to the above aspect, an appropriate back pressure can be applied for an appropriate period of time when the metal plate W is punched to form the iron core member 5.

[0088] In the laminated core manufacturing apparatus 10 of this embodiment, the upper die control unit 92 of the control device 90 may control the lowering and raising of the punch 45 so that the punch 45 maintains a penetrating state with respect to the punching hole WH formed by punching the metal plate W with the punch 45 from the time the punch 45 punches the metal plate W until the output torque of the lifting motor 36 is changed from the second output torque to the first output torque. According to the above embodiment, the punch 45 moves in the axial direction of the punching hole WH (i.e., the vertical direction) based on the punching hole WH formed in the metal plate W that has been positioned relative to the mounting table 30 by inserting the pilot pin 50 into the pilot hole PH. Therefore, the concentricity of the punch 45 with respect to the axial center of the punching hole WH can be maintained during the change of the output torque from the second output torque to the first output torque.

[0089] In the laminated core manufacturing apparatus 10 of this embodiment, the upper die control unit 92 of the control device 90 may control the vertical movement of the stripper plate 60 so as to restrict the movement of the metal plate W in the vertical direction Z during at least a part of the period during which the outer shape punching punch 45 maintains a penetrating state through the punching hole WH formed by punching the metal plate W with the outer shape punching punch 45. According to the above aspect, the outer shape punching punch 45 moves in the axial direction of the punching hole WH (i.e., in the vertical direction) based on the punching hole WH formed in the metal plate W whose movement in the vertical direction Z is restricted by the stripper plate 60, so that the concentricity of the outer shape punching punch 45 with respect to the axial center of the punching hole WH can be maintained while the output torque is changed from the second output torque to the first output torque.

[0090] Although the preferred embodiments of the present invention have been described above, the above-described embodiments are merely examples, and the present invention can be embodied in various other forms.

[0091] In the above-described embodiment, the stacked core members 5 are joined to each other by crimping, but the method of joining them is not limited to crimping. The stacked core members 5 may be joined to each other by, for example, welding, adhesion, or the like. When the stacked core members 5 are joined to each other by adhesion, the torque control unit 94 may be configured to change the first output torque according to the number of bonding points when bonding one core member 5. Bonding one core member 5 means stacking and bonding an iron core member 5 formed by punching a metal plate W on an iron core member 5 already placed on the mounting table 30. The torque control unit 94 may be configured to lower the first output torque as the number of bonding points decreases. In addition, the torque control unit 94 may be configured to change the second output torque according to the number of bonding points when bonding one core member 5. The torque control unit 94 may be configured to increase the second output torque as the number of bonding points increases.

[0092] When the stacked core members 5 are bonded to each other by adhesion, the manufacturing apparatus 10 may include an adhesive applicator that applies adhesive to the underside WL (see FIG. 1) of the metal plate W. In this case, the control device 90 includes an application control unit that controls the adhesive applicator. The application control unit may control the adhesive applicator to apply adhesive to the underside WL of the metal plate W during at least a portion of the period during which the torque control unit 94 sets the output torque of the lifting motor 36 to the second output torque.

[0093] In the above-described embodiment, the lower die body 21, the die plate 22, and the die 23 of the lower die 20 are configured as separate bodies, but they may be configured as an integral body as appropriate. For example, the die plate 22 and the die 23 may be configured as an integral body, or the die plate 22, the die 23, and the lower die body 21 may be configured as an integral body.

[0094] In the above-described embodiment, the upper surface 23T of the die 23 and the upper surface 22T of the die plate 22 are located at the same height, but are not limited to this. For example, the upper surface 23T of the die 23 may be located lower than the upper surface 22T of the die plate 22. In this case, the stripper plate 60 presses the belt-shaped metal sheet W against the upper surface 22T of the die plate 22.

[0095] In the above-described embodiment, the manufacturing apparatus 10 was equipped with a punch 45 for punching the outer shape and a die hole 26 for punching the outer shape, but it may further be equipped with a punch for punching the inner shape and a die hole for punching the inner shape, a punch for forming a pilot hole and a die hole for forming a pilot hole, etc.

[0096] In a series of manufacturing steps from the start of punching the first core member 5 to the discharge of the laminated core 8 to the outside of the manufacturing apparatus 10, the first output torque or the second output torque may be changed as described in the claims. Also, in different manufacturing steps, the first output torque or the second output torque may be changed as described in the claims. [Explanation of symbols]

[0097] 5 Core material 8 Laminated core 10 Manufacturing equipment (laminated iron core manufacturing equipment) 20 Lower mold 23 Die 26 Die hole for punching the outer shape (Die hole) 30 Placement table 32 Support member 36 Lift motor 40 Upper mold 45 Outline punching punch (punch) 90 Control device 94 Torque control section

Claims

1. A manufacturing apparatus for a laminated core in which a plurality of core members are stacked and bonded to each other, comprising: A lower mold having a die with a die hole formed therein; an upper die having a punch corresponding to the die hole and punching out a strip-shaped metal plate to form the core member; a mounting table that is provided so as to be movable up and down and on which the formed core members are successively placed; A support member that supports the mounting table so that the mounting table can be raised and lowered; a lifting motor for lifting and lowering the stage via the support member; a squeeze ring disposed below the die and configured to apply lateral pressure to the core member placed on the mounting table; a control device for controlling the upper mold and the lifting motor, The control device includes: a torque control unit that changes an output torque of the lifting motor from a first output torque to a second output torque higher than the first output torque during a period from when a lower surface of the punch passes an intermediate point between a top dead point and a bottom dead point to when the lower surface of the punch reaches the bottom dead point, The torque control unit changes the output torque of the lifting motor from the first output torque to the second output torque between the time when the lower surface of the punch passes the midpoint and before the lower surface of the punch contacts the upper surface of the metal plate.

2. A manufacturing apparatus for a laminated core in which a plurality of core members are stacked and bonded to each other, comprising: A lower mold having a die with a die hole formed therein; an upper die having a punch corresponding to the die hole and punching out a strip-shaped metal plate to form the core member; a mounting table that is provided so as to be movable up and down and on which the formed core members are successively placed; A support member that supports the mounting table so that the mounting table can be raised and lowered; a lifting motor for lifting and lowering the stage via the support member; a squeeze ring disposed below the die and configured to apply lateral pressure to the core member placed on the mounting table; a control device for controlling the upper mold and the lifting motor, The control device includes: a torque control unit that changes an output torque of the lifting motor from a first output torque to a second output torque higher than the first output torque during a period from when a lower surface of the punch passes an intermediate point between a top dead point and a bottom dead point to when the lower surface of the punch reaches the bottom dead point, The torque control unit changes the output torque of the lifting motor from the first output torque to the second output torque between the time when the iron core member formed by punching the metal plate starts to fall downward and the time when the lower surface of the punch reaches the bottom dead center.

3. 3. The manufacturing apparatus of claim 2, wherein the torque control unit changes the output torque of the lifting motor from the first output torque to the second output torque during the period from when the iron core member formed by punching out the metal plate starts to fall downward to when the formed iron core member abuts against an upper surface of the iron core member placed on the mounting table.

4. 3. The manufacturing apparatus according to claim 2, wherein the torque control unit changes the output torque of the lifting motor from the first output torque to the second output torque during a period from when the core member formed by punching the metal plate abuts against an upper surface of the core member placed on the mounting table until the lower surface of the punch reaches the bottom dead center.

5. A manufacturing apparatus for a laminated core in which a plurality of core members are stacked and bonded to each other, comprising: A lower mold having a die with a die hole formed therein; an upper die having a punch corresponding to the die hole and punching out a strip-shaped metal plate to form the core member; a mounting table that is provided so as to be movable up and down and on which the formed core members are successively placed; A support member that supports the mounting table so that the mounting table can be raised and lowered; a lifting motor for lifting and lowering the stage via the support member; a control device for controlling the upper mold and the lifting motor, The control device includes: a torque control unit that changes the output torque of the lifting motor from a second output torque higher than the first output torque to the first output torque during the time period until the lower surface of the punch moves from the bottom dead point to the midpoint between the bottom dead point and the top dead point.

6. 6. The manufacturing apparatus of claim 5, wherein the torque control unit changes the output torque of the lifting motor from the second output torque to the first output torque when the lower surface of the punch starts to rise from the bottom dead center.

7. The manufacturing apparatus according to claim 5 , wherein the torque control unit changes the output torque of the lift motor from the second output torque to the first output torque in a rectangular wave shape.

8. The manufacturing apparatus according to claim 5 , wherein the torque control unit gradually changes the output torque of the lifting motor from the second output torque to the first output torque.

9. 6. The manufacturing apparatus of claim 5, wherein the timing at which the torque control unit changes the output torque of the lifting motor from the second output torque to the first output torque is the same in a first punching process in which the metal plate is punched with the punch to form a first core member, and a second punching process in which the metal plate is punched with the punch to form a second core member.

10. The manufacturing apparatus according to claim 5 , wherein the torque control unit is configured to be able to change the first output torque.

11. a squeeze ring disposed below the die and configured to apply a lateral pressure to the core member placed on the mounting table; The manufacturing apparatus according to claim 10 , wherein the torque control unit is configured to reduce the first output torque as a lateral pressure applied from the squeeze ring to the core member becomes smaller.

12. The manufacturing apparatus according to claim 5 , wherein the torque control unit is configured to be able to change a timing at which the output torque of the lifting motor is changed from the second output torque to the first output torque.

13. 13. The manufacturing apparatus of claim 12, wherein the torque control unit is configured to be able to change the first output torque, and is configured to delay the timing at which the change of the output torque of the lift motor from the second output torque to the first output torque is completed as the first output torque becomes lower.

14. 13. The manufacturing apparatus of claim 12, wherein the torque control unit is configured to be able to change at least one of the first output torque and the second output torque, and is configured to delay the timing at which the change of the output torque of the lifting motor from the second output torque to the first output torque is completed as the difference between the first output torque and the second output torque becomes larger.

15. a pilot pin provided on the upper die and inserted into a pilot hole formed in the metal plate to position the metal plate relative to the mounting table; 6. The manufacturing apparatus according to claim 5, wherein the control device controls the descent and ascent of the punch so that the punch maintains a penetrating state with respect to a punched hole formed by punching the metal plate with the punch, from the time when the punch punches the metal plate until the output torque of the lifting motor is changed from the second output torque to the first output torque.

16. a stripper plate that is provided in the upper die and that restricts the metal plate from moving in a vertical direction when the metal plate is punched out by the punch; The manufacturing apparatus of claim 15, wherein the control device controls the vertical movement of the stripper plate so as to restrict the vertical movement of the metal plate during at least a portion of a period during which the punch maintains a penetrating state relative to a punched hole formed by punching the metal plate with the punch.

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