Lamination thickness control device and method, and laminate manufacturing apparatus and method
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NHK SPRING CO LTD
- Filing Date
- 2025-11-06
- Publication Date
- 2026-05-21
Smart Images
Figure JP2025038898_21052026_PF_FP_ABST
Abstract
Description
Laminated thickness control device and method, and laminate manufacturing device and method
[0001] The present invention relates to a laminated thickness control device and method, and a laminate manufacturing device and method used when manufacturing a laminate such as a core or a block for a rotating electrical machine such as an electric motor or a generator.
[0002] As a method for manufacturing a laminate of a rotating electrical machine, a method of manufacturing a laminate such as a core by laminating a plurality of plate-shaped core pieces is known. When manufacturing a laminate, generally, the laminated thickness of the laminate, which is the thickness in the lamination direction of the core pieces, is controlled so as to be within the tolerance of a predetermined value.
[0003] For example, the thickness of one core piece is measured, and the number of core pieces to be laminated is determined so that the laminated thickness of the laminate converted from the measured thickness of the core piece and the number is within the tolerance of a predetermined value. However, there was a problem that the converted laminated thickness of the laminate deviated from the actual laminated thickness of the laminate including gaps between the core pieces.
[0004] On the other hand, in the method of Patent Document 1, the laminated thickness of the laminate is measured, and a correction value for the thickness of each core piece is calculated from the deviation between the converted laminated thickness of the laminate and the measured actual laminated thickness of the laminate. By considering this correction value, the deviation between the converted laminated thickness of the laminate and the measured laminated thickness is corrected.
[0005] However, since the measured value of the thickness of the core piece, which is the basis for conversion, may vary depending on the temperature of the measurement environment, the method of Patent Document 1 has a limit in the accuracy of controlling the laminated thickness of the laminate.
[0006] Japanese Patent Application Laid-Open No. 2019-041474
[0007] The problem to be solved is that there is a limit in the accuracy of controlling the laminated thickness of the laminate.
[0008] The present invention provides a stacking thickness control device comprising: a first sensor for measuring the thickness of each core piece; a second sensor for measuring the temperature of the first sensor; a first calculation unit for determining a first correction value for the thickness measured by the first sensor based on the temperature measured by the second sensor; and a second calculation unit for adjusting the number of core pieces stacked to form a laminate having a predetermined stacking thickness based on the thickness of each core piece and the first correction value.
[0009] Furthermore, the present invention provides a laminate manufacturing apparatus having the above-mentioned stacking thickness control device, comprising a press machine that performs a progressive press on a sheet material to punch out the core pieces from the sheet material and laminate them, wherein the first sensor measures the thickness of the sheet material when the deflection and vibration of the sheet material due to the progressive press does not exceed a threshold.
[0010] Furthermore, the present invention provides a stacking thickness control method which involves measuring the thickness of each core piece with a sensor, measuring the temperature of the sensor, determining a first correction value for the thickness measured by the sensor based on the temperature of the sensor, and adjusting the number of core pieces stacked to form a laminate having a predetermined stacking thickness based on the thickness of each core piece and the first correction value.
[0011] Furthermore, the present invention provides a method for manufacturing a laminate having a stacking thickness control method, wherein a progressive press is performed on a sheet material using a press machine to punch out the core pieces from the sheet material and stack them, and the thickness of the sheet material is measured by a sensor when the deflection and vibration of the sheet material due to the progressive press do not exceed a threshold.
[0012] This invention can improve the accuracy of controlling the stacking thickness of laminates.
[0013] Figure 1 is a schematic side view showing a core manufacturing apparatus according to Embodiment 1 of the present invention. Figures 2(A) and 2(B) are schematic front views showing a part of the press machine of the core manufacturing apparatus of Figure 1. Figure 3 is a schematic front view showing the thickness sensor and temperature sensor of the core manufacturing apparatus of Figure 1. Figure 4 is a flowchart of the core manufacturing method according to Embodiment 1. Figure 5 is a schematic front view showing a core manufacturing apparatus according to Embodiment 2 of the present invention. Figure 6 is a flowchart of the core manufacturing method according to Embodiment 2.
[0014] One embodiment of the stacking thickness control device 13 includes a first sensor 29, a second sensor 31, a first calculation unit 33, and a second calculation unit 35.
[0015] The first sensor 29 measures the thickness of each core piece P. The second sensor 31 measures the temperature of the first sensor 29. The first calculation unit 33 determines a first correction value for the thickness measured by the first sensor 29 based on the temperature measured by the second sensor 31. The second calculation unit 35 adjusts the number of core pieces P to be stacked in order to form a laminate C having a predetermined stacking thickness, based on the thickness of each core piece P and the first correction value.
[0016] The stacking thickness control device 13 may also include a third sensor 27 and a third calculation unit 37.
[0017] The third sensor 27 measures the stacking thickness of the laminate C. The third calculation unit 37 determines a second correction value for the plate thickness of each core piece P based on the difference between the stacking thickness measured by the third sensor 27 and a predetermined stacking thickness. In this case, the second calculation unit 35 adjusts the number of stacked core pieces P based on the plate thickness of each core piece P, the first correction value, and the second correction value.
[0018] The stacking thickness control device 13 may also include a pressurizing unit 25 that applies pressure to the stacked body C in the thickness direction when measuring the stacking thickness, with a higher pressure than when stacking the core pieces P.
[0019] The stacking thickness control device 13 may also include a fourth sensor 39 and a fourth calculation unit 41. The fourth sensor 39 measures the temperature of the laminate C. The fourth calculation unit 41 determines a third correction value for the thickness of each core piece P based on the temperature measured by the fourth sensor 39. In this case, the second calculation unit 35 adjusts the number of core pieces P to be stacked based on the thickness of each core piece P and the first, second, and third correction values.
[0020] The first sensor 29 may comprise sensor bodies 29a and 29b facing each other in the thickness direction of the core piece P to be measured, and a holder 29c that holds the sensor bodies 29a and 29b. In this case, the second sensor 31 measures the temperature of the holder 29c.
[0021] The laminate manufacturing apparatus 1, which has a stacking thickness control device 13, includes a press machine 9. The press machine 9 performs progressive pressing on a sheet material W, punching out core pieces P from the sheet material W and stacking them. In this laminate manufacturing apparatus 1, the first sensor 29 of the stacking thickness control device 13 measures the thickness of the sheet material W when the deflection and vibration of the sheet material W due to progressive pressing do not exceed a threshold.
[0022] In one embodiment, the laminate manufacturing apparatus 1 may measure the thickness of the sheet material W in response to the operation of the stripper 19. The stripper 19 holds down the sheet material W when punching out each core piece P and releases from the sheet material W after punching out each core piece P. In this case, the first sensor 29 measures the thickness of the sheet material W at least while the sheet material W is held down by the stripper 19.
[0023] In this case, the laminate manufacturing apparatus 1 may measure the thickness of the sheet material W in accordance with the operation of the crank 21a that raises and lowers the upper die 17 of the press machine 9. In this case, it is preferable that the first sensor 29 measures the thickness of the sheet material W when the crank angle of the crank 21a is less than 180 degrees.
[0024] More preferably, if the punching time is defined as from at least before the punching of each core piece P until the punching of each core piece P, the first sensor 29 performs the measurement while the stripper 19 is holding down the sheet material W and before the punching of each core piece P is performed.
[0025] The stacking thickness control method involves measuring the thickness of each core piece P using a sensor 29, measuring the temperature of the sensor 29, and determining a first correction value for the thickness measured by the sensor 29 based on the temperature of the sensor 29. Then, the number of core pieces P stacked to form a laminate C having a predetermined stacking thickness is adjusted based on the thickness of each core piece P and the first correction value.
[0026] As with the stacking thickness control device 13, the stacking thickness control method may measure the stacking thickness of the laminate C and determine a second correction value for the plate thickness based on the difference between the measured stacking thickness and a predetermined stacking thickness. Alternatively, the stacking thickness control method may measure the temperature of the laminate C and determine a third correction value for the plate thickness based on the measured temperature of the laminate C. Furthermore, the laminate C may be pressed in the stacking direction with a higher pressure than when stacking the core pieces P during the stacking thickness measurement.
[0027] If the sensor 29 comprises sensor bodies 29a and 29b facing each other in the thickness direction of each core piece P, and a holder 29c that holds the sensor bodies 29a and 29b, the temperature of the holder 29c may be measured as the temperature of the sensor 29.
[0028] In a laminate manufacturing method to which the above-described thickness control method is applied, such as in the laminate manufacturing apparatus 1, the thickness of the sheet material W may be measured by the sensor 29 when the deflection and vibration of the sheet material W due to the progressive press do not exceed a threshold. Alternatively, the thickness of the sheet material W may be measured by the sensor 29 at least while the sheet material W is being held down by the stripper 19, for example, the thickness of the sheet material W may be measured before the crank angle of the crank 21a reaches 180 degrees. Furthermore, it is preferable to perform the measurement before punching out the core piece P.
[0029] [Core Manufacturing Apparatus] Figure 1 is a schematic diagram showing a core manufacturing apparatus according to Embodiment 1 of the present invention.
[0030] The core manufacturing apparatus 1 shown in Figure 1 is a laminate manufacturing apparatus of this embodiment that manufactures a laminated core C by sequentially punching out multiple plate-shaped core pieces P from a plate material W and stacking them. In this core manufacturing apparatus 1, the stacking thickness of the core C is controlled to be within a predetermined tolerance. In the following, the predetermined value of the stacking thickness of the core C and its tolerance will be referred to as the predetermined stacking thickness.
[0031] Core C is a columnar body that constitutes the rotor core or stator core of a rotating electric machine. Rotating electric machines include electric motors and generators. The laminate can also be made up of blocks. In this case, the core is made up of multiple blocks stacked on top of each other.
[0032] This core manufacturing apparatus 1 comprises a controller 3, an uncoiler 5, a feed device 7, a guide 8, a press machine 9, a stacking thickness measuring machine 11, and a stacking thickness control device 13.
[0033] Controller 3 is a control unit that controls each part of the core manufacturing apparatus 1. In this embodiment, Controller 3 consists of a computer having a processor and memory (RAM, ROM, HDD, SSD), etc. Although Controller 3 is composed of a single computer, it can also be composed of multiple computers.
[0034] The uncoiler 5 is a well-known uncoiler on which a coil material CW is rotatably mounted. The coil material CW is a sheet material W, which is a strip of electromagnetic steel sheet, wound into a roll. The uncoiler 5 allows the sheet material W to be fed by the rotation of the coil material CW around its axis. The feeding of the sheet material W is performed by a feeding device 7.
[0035] The feeding device 7 intermittently feeds the sheet metal W toward the press machine 9. While the feeding device 7 can be configured as appropriate, in this embodiment it is equipped with rollers 7a and 7b.
[0036] Rollers 7a and 7b grip the sheet metal W from both sides in the thickness direction, from above and below, and repeatedly rotate and stop. The thickness direction of the sheet metal W and core piece P will be described below as the vertical direction. The sheet metal W is fed out when rollers 7a and 7b rotate. Rollers 7a and 7b can be driven by a servo motor or the like (not shown). Between this feeding device 7 and the uncoiler 5, a guide 8 and a thickness sensor 29 of the stacking thickness control device 13 (described later) are arranged.
[0037] The guide 8 guides the sheet metal W between the uncoiler 5 and the feed device 7 to suppress flapping of the sheet metal W. The sheet metal W can be guided by any appropriate method, but in this embodiment, the sheet metal W is folded multiple times.
[0038] Figures 2(A) and (B) are schematic front views showing a part of the press machine 9.
[0039] As shown in FIGS. 1 to 2(B), the press machine 9 performs progressive pressing on the plate material W, punches out plate-shaped core pieces P from the plate material W, and stacks them. The press machine 9 of this embodiment includes a lower die 15, an upper die 17, and a stripper 19.
[0040] The lower die 15 and the upper die 17 have the plate material W sent between them, and the upper die 17 descends to punch out the core piece P from the plate material W. Then, when the upper die 17 ascends, the plate material W is sent to prepare for the next punching. The ascending and descending of the upper die 17 are performed by a drive mechanism 21.
[0041] The punched core piece P is held in the lower die 15 under side pressure. By repeating the punching and holding of the core piece P a plurality of times according to the progressive pressing, a core C in which a plurality of core pieces P are stacked is formed.
[0042] When the core pieces P are stacked, the core pieces P are pressurized by the pressure of the press. Through this pressurization, in the core C, the core pieces P are joined together by an adhesive or caulking. When the formed core C is discharged from the press machine 9, it is sent to the thickness measuring machine 11 by the conveyor 23. Note that the core C can also be sent to the thickness measuring machine 11 manually or by a robot.
[0043] The stripper 19 is supported by the upper die 17 by a spring or the like. This stripper 19 abuts on the plate material W prior to the descent of the upper die 17. Thereby, the stripper 19 holds down the plate material W when punching out each core piece P. The punching of each core piece P is at least from before the execution of punching each core piece P to during the execution of punching each core piece P.
[0044] In this embodiment, the plate material W is held down by the stripper 19 from before the execution of punching each core piece P. Also, after the execution of punching each core piece P, the stripper 19 abuts on the plate material W by the stroke amount according to the ascent of the upper die 17 and then ascends together with the upper die 17 to separate from the plate material W. For this reason, the stripper 19 holds down the plate material W before and after the execution of punching, which is the punching time of each core piece P corresponding to its stroke, and ascends together with the upper die 17 to separate from the plate material W after punching.
[0045] The drive mechanism 21 includes a crank 21a, a rod 21b, and a slide 21c that connect the crank 21a to the upper die 17. The crank 21a moves the rod 21b and the slide 21c up and down according to rotation around the axis, and raises and lowers the upper die 17 through the rod 21b and the slide 21c. In the raising and lowering of the upper die 17, the crank angle becomes 0 degrees at the top dead center of the crank 21a as shown in Fig. 2(A), and the crank angle becomes 180 degrees at the bottom dead center of the crank 21a as shown in Fig. 2(B).
[0046] The rotation of the crank 21a can be performed by a servo motor or the like (not shown). The crank angle of the crank 21a is detected by an encoder of the servo motor or the like, but it is also possible to provide a dedicated sensor.
[0047] The core thickness measuring device 11 in Fig. 1 measures the core thickness (the height of the core C in the stacking direction of the core pieces P). The core thickness measuring device 11 may adopt an appropriate one, but in this embodiment, it includes a pressing unit 25 and a distance sensor 27.
[0048] The pressing unit 25 presses the core C in the vertical direction with a higher pressing force when measuring the core thickness of the core C than when laminating the core pieces P. The pressing unit 25 in this embodiment includes clamping members 25a and 25b and a drive unit 25c.
[0049] The clamping members 25a and 25b are flat plates and face each other in the vertical direction. One clamping member 25a (upper in this embodiment) is supported so as to be movable in the vertical direction with respect to the other clamping member 25b (lower in this embodiment). This one clamping member 25a is driven by the drive unit 25c to move.
[0050] The drive unit 25c is constituted by a linear actuator such as a cylinder mechanism connected to one clamping member 25a. The drive unit 25c operates the clamping member 25a in the vertical direction to move the clamping members 25a and 25b closer to and away from each other. When the clamping members 25a and 25b approach each other, the core C located between them is pressed.
[0051] The distance sensor 27 measures the thickness of the core C being compressed between the clamping members 25a and 25b by measuring the distance between them. The measured thickness is input to the controller 3. The distance sensor 27 can be, for example, provided on one of the clamping members 25a and can utilize light such as a laser. Alternatively, the thickness of the core C can be measured by an encoder or the like provided on the drive unit 25c instead of the distance sensor 27.
[0052] The stacking thickness control device 13 controls the stacking thickness of the core C so that it falls within a predetermined tolerance (predetermined stacking thickness). This stacking thickness control device 13 comprises a thickness sensor 29, a temperature sensor 31, the distance sensor 27, a first calculation unit 33, a second calculation unit 35, and a third calculation unit 37.
[0053] Figure 3 is a schematic diagram showing the thickness sensor 29 and temperature sensor 31 of the core manufacturing apparatus 1 shown in Figure 1.
[0054] The thickness sensor 29 is the first sensor in this embodiment, which measures the thickness of each core piece P, as shown in Figures 1 and 3. This thickness sensor 29 is positioned between the guide 8 and the feeding device 7 in the feeding direction of the sheet material W, and measures the thickness of the sheet material W. The measured thickness of the sheet material W is transmitted to the controller 3.
[0055] In the controller 3, the thickness of each core piece P is measured directly or indirectly based on the measured thickness of the plate material W, as described later. Therefore, the thickness sensor 29 measures the thickness of each core piece P by measuring the thickness of the plate material W.
[0056] The thickness sensor 29 in this embodiment is a non-contact laser displacement sensor and comprises a sensor body 29a and 29b and a holder 29c.
[0057] The sensor bodies 29a and 29b face each other in the vertical direction, which is the thickness direction of the core piece P to be measured. The sensor bodies 29a and 29b are positioned with the plate material W between them in the vertical direction, and emit a laser towards the plate material W to measure the thickness of the plate material W. These sensor bodies 29a and 29b are held by the holder 29c. The thickness sensor 29 can also consist of a single sensor body.
[0058] The holder 29c holds the sensor bodies 29a and 29b to the plate material W. In this embodiment, the holder 29c is a frame, but it may be other members that fix the frame. Also, the holder 29c may be an arm or the like instead of a frame.
[0059] The holder 29c is configured as a rectangular ring when viewed from the feeding direction of the plate material W, and has an opening 29d on its inside through which the plate material W is inserted. Above and below the opening 29d of the holder 29c, the sensor bodies 29a and 29b are fixed and held, facing each other vertically. A temperature sensor 31 is attached to this holder 29c.
[0060] The temperature sensor 31 is the second sensor in this embodiment, which measures the temperature of the thickness sensor 29. The temperature sensor 31 measures the temperature of the holder 29c. However, the temperature sensor 31 only needs to measure the temperature of an appropriate location on the thickness sensor 29.
[0061] The measured temperature of the holder 29c is transmitted to the controller 3. In this embodiment, the temperature sensor 31 is a contact type such as a thermistor and is attached to the holder 29c. However, the temperature sensor 31 may also be a non-contact type.
[0062] The distance sensor 27 is the third sensor in this embodiment, which measures the stacking thickness of the core C as described above. The measured stacking thickness of the core C is transmitted to the controller 3 as described above.
[0063] The controller 3 functions as the first, second, and third arithmetic units 33, 35, and 37 by executing programs in memory using the processor.
[0064] The first calculation unit 33 is a software unit that determines a first correction value for the plate thickness of each core piece P measured by the thickness sensor 29, based on the temperature of the thickness sensor 29 measured by the temperature sensor 31. The first calculation unit 33 can also be configured as a unit consisting of a computer independent of the controller 3. The same applies to the second and third calculation units 35 and 37.
[0065] The first correction value is set, for example, when the difference between the temperature measured by the thickness sensor 29 and the temperature at the time the previous first correction value was set exceeds a threshold. The first correction value may also be set at regular time intervals.
[0066] When setting the first correction value, the first calculation unit 33 receives and acquires the temperature of the holder 29c, which is measured as the temperature of the thickness sensor 29, from the temperature sensor 31. Then, the first calculation unit 33 determines the first correction value for the plate thickness of the core piece P based on the correlation between the temperature change of the thickness sensor 29 and the fluctuation of the measured value. This correlation can be obtained in advance through experiments or other means.
[0067] This correlation is based on the fact that, for example, the holder 29c of the thickness sensor 29 expands and contracts in the up, down, left, and right directions in Figure 3 in response to temperature, causing the distance between the sensor body 29a and 29b and the plate material W to fluctuate. As a result, the thickness sensor 29 causes fluctuations in the measured thickness of the core piece P. Therefore, as described above, there is a correlation between the temperature of the thickness sensor 29 and the fluctuation in the measured thickness of the core piece P, and this correlation is obtained through experiments or other means.
[0068] Based on this correlation, the first calculation unit 33 sets the change in the measured thickness of the core piece P between the temperature at the time the first correction value was set immediately before the thickness sensor 29 was set and the temperature measured by the thickness sensor 29 as the first correction value. If the first correction value has not been set immediately before, the change in the measured value between the reference temperature and the temperature measured by the thickness sensor 29 may be used as the first correction value. The reference temperature can be set as appropriate, but for example, it may be 25 degrees (room temperature).
[0069] The thickness of the core piece P is obtained directly or indirectly by the first calculation unit 33 based on the thickness of the sheet metal W received from the thickness sensor 29, as described above. The thickness received by the first calculation unit 33 from the thickness sensor 29 is the thickness measured while the sheet metal W is held down by the stripper 19, preferably before the crank angle reaches 180 degrees. More preferably, the measurement of the thickness before the crank angle reaches 180 degrees is the measurement of the thickness before punching out each core piece P and / or when the crank angle is between 160 and 175 degrees. The crank angle of 160 to 175 degrees is after, during, or before punching out each core piece P, depending on the specifications of each core piece P. The acquisition of the thickness of each core piece P can be performed by an appropriate method.
[0070] For example, in directly obtaining the thickness of the core piece P, the thickness sensor 29 measures the thickness of the portion of the sheet material W that will be punched out as the core piece P. The first calculation unit 33 obtains this measurement as the thickness of the core piece P. The thickness sensor 29 may also measure the thickness of one or more locations within the portion that will be punched out as the core piece P. If the thickness of multiple locations is measured, the average value, maximum value, or minimum value of these measurements can be used as the thickness of the core piece P. Alternatively, the thickness of the core piece P may be measured directly after the core piece P has been punched out.
[0071] In indirectly obtaining the thickness of the core pieces P, for example, the thickness of multiple locations on the sheet metal W other than the parts punched out as each core piece P is measured by the thickness sensor 29. The first calculation unit 33 then acquires these measured values and predicts the thickness of the parts of the sheet metal W that will be punched out as each core piece P based on the trend of the sheet metal W thickness based on the acquired measured values. Alternatively, the thickness of any location on the sheet metal W other than the parts punched out as each core piece P may be measured by the thickness sensor 29, and the first calculation unit 33 may acquire these measured values and consider them to be the thickness of each core piece P.
[0072] Furthermore, as an indirect method for obtaining the thickness of the core pieces P, the thickness of the portion of the plate material W that is punched out as a core piece P may be measured randomly or at predetermined intervals using the thickness sensor 29, and the measured thickness may be used as the thickness of the other portion of the core piece P that has not been measured.
[0073] The second calculation unit 35 is a software unit that adjusts the number of core pieces P stacked to form a core C having a predetermined stacking thickness based on the thickness of each core piece P and a first correction value. In this embodiment, the second calculation unit 35 adjusts the number of core pieces P based on the thickness of each core piece P, a first correction value, and a second correction value obtained by the third calculation unit 37.
[0074] In adjusting the number of core pieces P, for example, the measured thickness of the core piece P is used as the converted thickness by adding a first correction value and a second correction value. The number of core pieces P to be stacked is set so that the stacked thickness of the core C (converted stacked thickness), calculated from this converted thickness and the number of core pieces P, becomes a predetermined stacked thickness. Based on this setting of the number of core pieces P, the number of core pieces P to be punched out by the press machine 9 is set.
[0075] Furthermore, multiple core pieces P may be stacked until the cumulative converted thickness of multiple core pieces P, which includes the measured thickness of each core piece P and the first and second correction values added to the measured thickness, reaches a predetermined stacking thickness.
[0076] The third calculation unit 37 is a software unit that determines a second correction value for the plate thickness of each core piece P based on the difference between the stacked thickness of the core C measured by the distance sensor 27 and a predetermined stacked thickness. The third calculation unit 37 receives and acquires the stacked thickness of the core C measured by the distance sensor 27 from the distance sensor 27, and also reads and acquires the predetermined stacked thickness from memory.
[0077] The second correction value is set when the difference between the measured core C thickness and a predetermined thickness exceeds a threshold. The second correction value may also be set at regular time intervals.
[0078] The predetermined stacking thickness here can be set appropriately within the tolerance range of the target stacking thickness (predetermined value) for core C. For example, the predetermined stacking thickness can be the predetermined value, the upper limit or lower limit of the tolerance, or the average of the upper and lower limits.
[0079] The third calculation unit 37 then uses the value obtained by dividing the difference between the acquired core C stack thickness and the predetermined stack thickness by the number of core pieces P constituting the core C as the second correction value per core piece. Alternatively, the difference between the acquired measured stack thickness of the core C and the predetermined stack thickness may be used as the second correction value for the core C.
[0080] [Core Manufacturing Method] The following describes a core manufacturing method to which the stacking thickness control method is applied, along with the operation of the core manufacturing apparatus 1. Figure 4 is a flowchart of the core manufacturing method according to Example 1.
[0081] As shown in Figure 4, in the core manufacturing method of this embodiment, a core C is manufactured by sequentially punching out multiple core pieces P from a sheet material W and stacking them, and the stacking thickness of the manufactured core C is controlled to be within a predetermined stacking thickness, that is, within a predetermined tolerance value.
[0082] In this core manufacturing method, first, it is determined whether or not it is necessary to set a first correction value for the plate thickness of the core piece P (step S1).
[0083] The thickness of the core piece P is measured directly or indirectly based on the thickness of the sheet metal W measured by the thickness sensor 29 as described above. The thickness of the sheet metal W is measured by the thickness sensor 29 when the deflection and vibration of the sheet metal W due to the progressive press do not exceed a threshold. Therefore, the measurement accuracy of the thickness of the sheet metal W, and consequently the measurement accuracy of the thickness of the core piece P, can be improved.
[0084] In this embodiment, the thickness of the sheet metal W is measured while the sheet metal W is held down by the stripper 19. Therefore, the sheet metal W can be reliably measured before its deflection and vibration exceed a threshold, thereby improving the accuracy of the measurement of the thickness of the sheet metal W and core piece P. In particular, when the thickness of the sheet metal W is measured before the crank angle of the crank 21a is 180 degrees, the effects of vibrations that occur when the upper die 17 passes near the bottom dead center can be reduced. Furthermore, when the thickness of the sheet metal W is measured before punching out the core piece P, the sheet metal W can be measured while its deflection and vibration are suppressed more reliably. Furthermore, when the thickness of the sheet metal W is measured between 160 and 175 degrees, the effects of vibrations due to deceleration during the feeding of the sheet metal W can be reduced. Therefore, the timing at which the deflection and vibration of the sheet metal W do not exceed a threshold can be accurately captured.
[0085] The first calculation unit determines whether a first correction value is necessary for the thickness of the core piece P measured in this way. This determination is made based on whether the difference between the temperature of the thickness sensor 29 measured by the temperature sensor 31 and the temperature of the thickness sensor 29 when the previous first correction value was set exceeds a threshold.
[0086] The temperature of the thickness sensor 29 when the previous first correction value was set can be read from the memory of the controller 3. If the previous first correction value has not been set, it is determined whether the difference between the reference temperature, for example 25 degrees, and the measured temperature of the thickness sensor 29 exceeds a threshold.
[0087] If the first correction value is to be reset at predetermined intervals, the need to set the first correction value can be determined by whether or not a predetermined amount of time has elapsed since the previous setting of the first correction value. This can be achieved by having the first calculation unit 33 activate a timer each time it sets the first correction value.
[0088] If it is necessary to set a first correction value, that is, if the difference between the temperature measured by the thickness sensor 29 and the temperature when the first correction value was set most recently exceeds a threshold (YES), the first calculation unit 33 sets a first correction value for the core piece P (step S2). Otherwise (NO), it determines whether it is necessary to set a second correction value, as will be described later (step S3).
[0089] The first correction value is set based on the correlation between the temperature change of the thickness sensor 29 and the fluctuation of the measured value, as described above. The first correction value is the amount of change in the measured thickness of the core piece P between the temperature measured by the thickness sensor 29 and the temperature at which the previous first correction value was set.
[0090] Next, regardless of whether the first correction value is set or not, it is determined whether the second correction value needs to be set (step S3). In this embodiment, the third calculation unit 37 determines whether the difference between the stacked thickness of the core C measured by the distance sensor 27 and a predetermined stacked thickness exceeds a threshold. The core C measured by the distance sensor 27 is the one that was completed earlier. When manufacturing the first core C, since there is no previously completed core C, it is sufficient to prototype the core C for calibration.
[0091] If it is necessary to set a second correction value for the plate thickness, that is, if the difference between the stacked thickness of the core C measured by the distance sensor 27 and a predetermined stacked thickness exceeds a threshold (YES), the second calculation unit 35 sets a second correction value for the plate thickness (step S4). Otherwise (NO), the number of core pieces P stacked to constitute the core C is adjusted (step S5).
[0092] The second correction value is the difference between the measured stacking thickness of the core C and a predetermined stacking thickness. As described above, in this embodiment, the second correction value per core piece is obtained by dividing this difference by the number of core pieces P that make up the core C whose stacking thickness was measured.
[0093] The number of stacked core pieces P is adjusted based on the thickness of each core piece P, a first correction value, and a second correction value. In this embodiment, the converted thickness of the core C calculated from the number of core pieces P and the sum of the thickness of each core piece P, the first correction value, and the second correction value is set to a predetermined stack thickness. If no first correction value is set (when the first correction value is zero), the converted thickness is set based on the thickness of each core piece P and the second correction value. If no second correction value is set (when the second correction value is zero), the converted thickness is set based on the thickness of each core piece P and the first correction value. If neither the first nor the second correction value is set (when both the first and second correction values are zero), the thickness of each core piece P becomes the converted thickness.
[0094] The number of core pieces P to be stacked, adjusted in this way, is transmitted from the third calculation unit 37 to the press machine 9. The press machine 9 punches out the received number of core pieces P and stacks them to form a core C (step S6).
[0095] The formed core C is sent to the stacking thickness measuring machine 11 to measure its stacking thickness (step S7). During this stacking thickness measurement, the core C is pressed in the stacking direction by the pressing unit 25 with a higher pressure than when stacking the core pieces P. If the measured stacking thickness of the core C is within a predetermined stacking thickness (within a predetermined tolerance), the core C is considered a normal product. This measured stacking thickness of the core C is transmitted to the third calculation unit 37 and used to set the second correction value thereafter.
[0096] As described above, the stacking thickness control device 13 and method of this embodiment measure the thickness of each core piece P using a thickness sensor 29 and measure the temperature of the thickness sensor 29 using a temperature sensor 31. Based on the measured temperature of the thickness sensor 29, the first calculation unit 33 determines a first correction value for the thickness measured by the thickness sensor 29. Then, the second calculation unit 35 adjusts the number of core pieces P to be stacked in order to form a core C having a predetermined stacking thickness, based on the thickness of each core piece P and the first correction value.
[0097] Therefore, in this embodiment, even if the measured thickness of the plate material W varies due to the ambient temperature, the thickness of the core piece P can be corrected using a first correction value that takes the ambient temperature into account. As a result, the number of core pieces P stacked to form a core C with a predetermined stacking thickness can be accurately adjusted using the converted plate thickness, which is the corrected plate thickness. Therefore, in this embodiment, deviations of the stacking thickness of the core C from the predetermined stacking thickness can be suppressed, and the accuracy of stacking thickness control can be improved.
[0098] Furthermore, the stacking thickness control device 13 and method of this embodiment measure the stacking thickness of the core C using a distance sensor 27, and the third calculation unit 37 determines a second correction value for the plate thickness of each core piece P based on the difference between the measured stacking thickness and a predetermined stacking thickness.
[0099] Therefore, in this embodiment, the plate thickness of each core piece P can be adjusted by a second correction value that takes into account factors other than ambient temperature, thereby more reliably improving the accuracy of core C stacking thickness control. Moreover, by separating the first correction value for ambient temperature from the second correction value for other factors, the accuracy of each is improved. Thus, more reliably improving the accuracy of core C stacking thickness control is possible.
[0100] Furthermore, the stacking thickness control device 13 and method of this embodiment apply pressure to the core C in the stacking direction when measuring the stacking thickness with a higher pressure than when stacking the core pieces P using the pressurizing unit 25.Therefore, the stacking thickness of the core C can be accurately measured, improving the accuracy of the second correction value and more reliably improving the accuracy of core C stacking thickness control.
[0101] Furthermore, in this embodiment, the stacking thickness control device 13 and method measure the temperature of the holder 29c that holds the sensor bodies 29a and 29b using a temperature sensor 31 as the temperature of the thickness sensor 29. Therefore, the accuracy of the first correction value due to ambient temperature can be improved.
[0102] The stacking thickness control device 13 and method of this embodiment measure the thickness of the plate material W when the deflection and vibration of the plate material W due to the progressive press do not exceed a threshold. Therefore, the measurement accuracy of the plate material W that serves as the base for measuring the thickness of the core piece P can be improved.
[0103] Furthermore, in this embodiment, the thickness of the plate material W is measured at least while the plate material W is held down by the stripper 19, and more preferably before punching out the core piece P. This ensures that the plate material W is measured before its deflection and vibration exceed a threshold, thereby improving the accuracy of the plate material W thickness measurement. In particular, the thickness of the plate material W is measured when the crank angle of the crank 21a is between 160 and 175 degrees. This allows for accurate capture of the timing when the deflection and vibration of the plate material W do not exceed a threshold.
[0104] Figure 5 is a schematic diagram showing a core manufacturing apparatus according to Embodiment 2 of the present invention. Since Embodiment 2 has the same basic configuration as Embodiment 1, the corresponding components are indicated by the same reference numerals, and redundant explanations are omitted.
[0105] The core manufacturing apparatus 1 of Example 2 further includes a core temperature sensor 39 and a fourth calculation unit 41 compared to Example 1. The other configurations of Example 2 are the same as those of Example 1.
[0106] The core temperature sensor 39 is a fourth sensor in this embodiment that measures the temperature of the core C. The core temperature sensor 39 is non-contact and can be made of a well-known radiation temperature sensor or the like. In this embodiment, the core temperature sensor 39 is located near the stack thickness measuring machine 11. However, the core temperature sensor 39 only needs to be positioned so as to be able to measure the temperature of the formed core C, and it may be a contact type, and its position is not limited.
[0107] The fourth calculation unit 41 is a software unit that determines a third correction value for the plate thickness of each core piece P based on the temperature measured by the core temperature sensor 39.
[0108] The third correction value is the value per core piece, obtained by dividing the change in thickness due to temperature of core C by the number of core pieces P that make up core C. This third correction value can be determined from the correlation between the temperature change of core C and the change in thickness. This correlation can be determined in advance through experiments or other means.
[0109] Figure 6 is a flowchart of the core manufacturing method in this embodiment.
[0110] In the core manufacturing method of this embodiment, as shown in Figure 6, after determining whether a first correction value is necessary (step S1) and setting a second correction value (step S4), similar to the process in Embodiment 1, a determination is made as to whether a third correction value is necessary (step S11). That is, throughout steps S1 to S4, both the first and second correction values may be set, or one or both may not be set, but in either case, a determination is made as to whether a third correction value is necessary (step S11).
[0111] In determining whether or not to set a third correction value, the fourth calculation unit 41 determines whether the difference between the temperature of core C measured by the core temperature sensor 39 and the temperature of core C when the previous third correction value was set exceeds a threshold.
[0112] The temperature of core C when the previous third correction value was set can be read from the memory of controller 3. If the third correction value is not set, it is determined whether the difference between the reference temperature, for example 25 degrees (room temperature), and the measured temperature of core C exceeds a threshold.
[0113] If the third correction value is to be reset at predetermined intervals, the need to set the third correction value can be determined by whether or not a predetermined amount of time has elapsed since the previous setting of the third correction value. This can be achieved by having the fourth calculation unit 41 activate a timer each time it sets the third correction value.
[0114] If a third correction value needs to be set, that is, if the difference between the measured temperature of core C and the temperature of core C when the previous third correction value was set exceeds a threshold (YES), the fourth arithmetic unit 41 sets the third correction value for core piece P (step S12). Otherwise (NO), the number of core pieces P stacked to constitute core C is adjusted (step S5).
[0115] In setting the third correction value, the change in the thickness of the core C between the measured temperature of the core C and the temperature of the core C at the time of setting the previous third correction value is used as the third correction value, based on the correlation between the temperature change and the thickness change of the core C. The core C whose temperature is measured is the one that was completed earlier. When manufacturing the first core C, a prototype core C should be made for calibration purposes.
[0116] After setting the third correction value, the number of core pieces P stacked to form the core C is adjusted (step S5). Here, to adjust the number of core pieces P, the plate thickness of each core piece P and the converted plate thickness calculated based on the first correction value, the second correction value, and the third correction value are used.
[0117] In other words, when a third correction value is set, the converted plate thickness is set based on the plate thickness of each core piece P, the second correction value, and the third correction value if there is no first correction value set (when the first correction value is zero); based on the plate thickness of each core piece P, the first correction value, and the third correction value if there is no second correction value set (when the second correction value is zero); and based on the plate thickness of each core piece P and the third correction value if there are no first or second correction values (when both the first and second correction values are zero). If there is no third correction value set (when the third correction value is zero), the number of core pieces P is adjusted in the same manner as in Example 1.
[0118] Then, the press machine 9 punches out a set number of core pieces P and stacks them to form a core C (step S6).
[0119] As described above, the stacking thickness control device 13 and method of this embodiment measure the temperature of the core C using the core temperature sensor 39 and determine a third correction value for the plate thickness of each core piece P based on the measured temperature of the core C. Therefore, the accuracy of the converted plate thickness of each core piece P can be improved, and the accuracy of core C stacking thickness control can be improved more reliably.
[0120] In addition, the same effects and advantages as in Example 1 can be achieved in Example 2.
[0121] 1 Core manufacturing equipment (laminated manufacturing equipment) 9 Press machine 13 Lamination thickness control device 17 Upper die 19 Stripper 21a Crank 25 Pressure unit 27 Distance sensor (third sensor) 29 Thickness sensor (first sensor) 29a, 29b Sensor body 29c Holder 31 Temperature sensor (second sensor) 33 First calculation unit 35 Second calculation unit 37 Third calculation unit 39 Core temperature sensor (fourth sensor) 41 Fourth calculation unit W Plate material P Core piece C Core
Claims
1. A stacking thickness control device comprising: a first sensor for measuring the thickness of each core piece; a second sensor for measuring the temperature of the first sensor; a first calculation unit for determining a first correction value for the thickness measured by the first sensor based on the temperature measured by the second sensor; and a second calculation unit for adjusting the number of core pieces stacked to form a laminate having a predetermined stacking thickness based on the thickness of each core piece and the first correction value.
2. A stacking thickness control device according to claim 1, comprising: a third sensor for measuring the stacking thickness of the laminate; and a third calculation unit for determining a second correction value for the plate thickness based on the difference between the stacking thickness measured by the third sensor and a predetermined stacking thickness, wherein the second calculation unit adjusts the number of core pieces to be stacked based on the plate thickness of each core piece, the first correction value, and the second correction value.
3. A stacking thickness control device according to claim 2, comprising a pressing unit that pressurizes the stacked body in the stacking direction when measuring the stacking thickness with a pressing force higher than that used when stacking the core pieces.
4. A stacking thickness control device according to claim 2 or 3, comprising: a fourth sensor for measuring the temperature of the stacked body; and a fourth calculation unit for determining a third correction value for the plate thickness based on the temperature measured by the fourth sensor, wherein the second calculation unit adjusts the number of core pieces to be stacked based on the plate thickness of each core piece, the first correction value, the second correction value, and the third correction value.
5. A stacking thickness control device according to any one of claims 1 to 3, wherein the first sensor comprises a sensor body facing the thickness direction of the core piece to be measured and a holder for holding the sensor body, and the second sensor measures the temperature of the holder.
6. A laminate manufacturing apparatus having a stacking thickness control device according to any one of claims 1 to 3, comprising a press machine that performs progressive pressing on a sheet material and punches out the core pieces from the sheet material for stacking, wherein the first sensor measures the thickness of the sheet material when the deflection and vibration of the sheet material due to the progressive pressing does not exceed a threshold.
7. A laminate manufacturing apparatus according to claim 6, comprising a stripper that holds the plate material when punching out each core piece and separates from the plate material after punching out each core piece, wherein the first sensor measures the thickness of the plate material at least while the plate material is held in place by the stripper.
8. A laminate manufacturing apparatus according to claim 7, wherein the press machine has an upper die and a crank for raising and lowering the upper die, and the first sensor measures the thickness of the plate material when the crank angle of the crank is less than 180 degrees.
9. A laminate manufacturing apparatus according to claim 8, wherein the punching occurs at least from before the punching of each core piece until the punching of each core piece, and the first sensor performs the measurement before the punching of each core piece.
10. A stacking thickness control method comprising: measuring the thickness of each core piece with a sensor; measuring the temperature of the sensor; determining a first correction value for the thickness measured by the sensor based on the temperature of the sensor; and adjusting the number of core pieces stacked to form a laminate having a predetermined stacking thickness based on the thickness of each core piece and the first correction value.
11. A stacking thickness control method according to claim 10, comprising: measuring the stacking thickness of the laminate; determining a second correction value for the plate thickness based on the difference between the measured stacking thickness and the predetermined stacking thickness; and adjusting the number of core pieces to be stacked based on the plate thickness of each core piece, the first correction value, and the second correction value.
12. A method for controlling the stacking thickness according to claim 11, wherein the stacked body is pressurized in the stacking direction at a higher pressure than when stacking the core pieces when measuring the stacking thickness.
13. A stacking thickness control method according to claim 11 or 12, comprising: measuring the temperature of the laminate; determining a third correction value for the plate thickness based on the measured temperature of the laminate; and adjusting the number of core pieces to be stacked based on the plate thickness of each core piece, the first correction value, the second correction value, and the third correction value.
14. A stacking thickness control method according to any one of claims 10 to 12, wherein the sensor comprises a sensor body facing the core piece to be measured in the thickness direction and a holder for holding the sensor body, and the temperature of the holder is measured as the temperature of the sensor.
15. A method for manufacturing a laminate having a stacking thickness control method according to any one of claims 10 to 12, comprising: performing a progressive press on a sheet material with a press machine to punch out the core pieces from the sheet material and stack them; and measuring the thickness of the sheet material with a sensor when the deflection and vibration of the sheet material due to the progressive press do not exceed a threshold.
16. A method for manufacturing a laminate according to claim 15, wherein the stripper holds the sheet material when punching out each core piece, separates from the sheet material after punching out each core piece, and measures the thickness of the sheet material by the sensor while at least the stripper is holding the sheet material.
17. A method for manufacturing a laminate according to claim 16, wherein the press machine has an upper die and a crank for raising and lowering the upper die, and the sensor measures the thickness of the plate material when the crank angle of the crank is less than 180 degrees.
18. A method for manufacturing a laminate according to claim 17, wherein the punching time is from before the execution of punching each core piece until the execution of punching each core piece, and the sensor performs the measurement before the execution of punching each core piece.