Punching sheet material, punching sheet material manufacturing device, punching device, and punching method

Abstract

Provided is a punching device capable of improving the production efficiency of punching.　A punching device 1A, which intermittently feeds a strip-shaped sheet 10 in the longitudinal direction thereof and sequentially feeds the strip-shaped sheet 10 into a die 73 to perform punching, includes an overlapping means (folding device 4, holding device 5) for folding a part of the strip-shaped sheet 10 to overlap another part of the strip-shaped sheet 10 before being fed into the die 73. Furthermore, it is preferable to provide an overlapping state stabilizing means (pinch roll device 6) for stabilizing the state in which part of the strip-shaped sheet 10 overlaps another part.

Description

Die-cut sheet material, die-cut sheet material manufacturing apparatus, die-cutting apparatus, and die-cutting method

[0001] The present invention relates to a die-cut sheet material subjected to die-cutting, a die-cut sheet material manufacturing apparatus for manufacturing the die-cut sheet material, a die-cutting apparatus for performing die-cutting on the die-cut sheet material, and a die-cutting method.

[0002] A laminated core is a component of an electric motor, and is constructed by stacking multiple core pieces punched into a predetermined shape from an electromagnetic steel sheet, and fastening adjacent core pieces together in the stacking direction.

[0003] The core pieces that make up the laminated core are usually manufactured by unwinding strip-shaped electromagnetic steel sheets (hereinafter referred to as "strip-shaped sheets") from a coil material, intermittently feeding the unwinding strip-shaped sheets in their longitudinal direction, and sequentially feeding the strip-shaped sheets into a die for punching (see, for example, Patent Document 1).

[0004] Japanese Patent Publication No. 2005-86929

[0005] In recent years, in order to improve the efficiency of electric motors, there has been a trend towards using thinner electrical steel sheets in laminated cores. Consequently, the number of core pieces constituting the laminated core tends to increase. An increase in the number of core pieces leads to an increase in the number of punching operations, which reduces production efficiency.

[0006] The present invention has been made in view of the above problems, and aims to provide a die-cut sheet material, a die-cut sheet material manufacturing apparatus, a die-cutting apparatus, and a die-cutting method that can improve the production efficiency of die-cutting.

[0007] The characteristic structure of the die-cutting plate material according to the present invention, which solves the above problems, is that it has a superimposed structure in which a part of the strip-shaped plate to be die-cut is superimposed on other parts.

[0008] This die-cutting sheet material has a superimposed structure in which a portion of the strip-shaped sheet to be die-cut is overlapped with other portions. Therefore, when die-cutting is performed on this die-cutting sheet material, multiple die-cut products can be obtained simultaneously in a single die-cutting operation. Consequently, the production efficiency of die-cutting can be improved.

[0009] In the die-cutting plate material according to the present invention, it is preferable that the strip-shaped plate is wound in a coil shape in the longitudinal direction.

[0010] According to this configuration of die-cutting sheet material, since it is in the form of a coil wound in the longitudinal direction of a strip-shaped sheet, it is easy to store and transport, and once the coiled die-cutting sheet material is set on the die-cutting line, it can be produced for a long time, making it suitable for mass production.

[0011] Next, a key feature of the die-cutting plate manufacturing apparatus according to the present invention, which solves the above problems, is that it includes a superposition means for overlapping a portion of a strip-shaped plate to be die-cut with other portions.

[0012] According to the die-cutting sheet metal manufacturing apparatus of this configuration, a portion of the strip-shaped sheet metal to be die-cut is folded by the overlapping means so that it overlaps with other parts, thereby enabling the production of die-cutting sheet metal having an overlapping structure in which a portion of the strip-shaped sheet metal overlaps with other parts.

[0013] In the die-cutting plate manufacturing apparatus according to the present invention, the overlapping means preferably includes a holding device for holding the strip-shaped plate and a bending device for bending the strip-shaped plate so that the portion of the strip-shaped plate overlaps the other portion along the longitudinal direction of the strip-shaped plate.

[0014] With this die-cutting sheet metal manufacturing apparatus, the cooperation between the holding device and the bending device ensures that a portion of the strip-shaped sheet metal is reliably bent so that it overlaps with other portions along the longitudinal direction of the strip-shaped sheet metal.

[0015] In the die-cutting plate manufacturing apparatus according to the present invention, the overlapping means preferably includes: a holding device for holding the strip-shaped plate; a notch forming device for forming notches extending in the short direction of the strip-shaped plate at predetermined intervals in the longitudinal direction on the short-side portion of the strip-shaped plate; and a bending device for folding the portion between adjacent notches in the longitudinal direction of the strip-shaped plate, treating this portion as a single part, so as to overlap the other portion along the short direction of the strip-shaped plate.

[0016] According to the die-cutting plate manufacturing apparatus of this configuration, notches extending in the short direction of the strip are formed on the short side of the strip at predetermined intervals in the longitudinal direction of the strip, and the portion between adjacent notches in the longitudinal direction of the strip is treated as one part, and the holding device and the bending device work together to reliably bend the strip so that one part overlaps the other part along the short direction of the strip.

[0017] In the die-cutting plate manufacturing apparatus according to the present invention, the overlapping means preferably includes a roll forming apparatus that overlaps a portion of the strip-shaped plate with another portion by forming rolls that hold the strip-shaped plate and feed it in the longitudinal direction.

[0018] With this die-cut sheet metal manufacturing apparatus, the roll forming apparatus can reliably bend a strip of sheet metal so that one part overlaps another part.

[0019] In the die-cutting plate manufacturing apparatus according to the present invention, it is preferable to further provide a superposition state stabilization means for stabilizing the state in which the one part is superimposed on the other part.

[0020] According to the die-cutting sheet metal manufacturing apparatus with this configuration, since the die-cutting process is performed on a strip-shaped sheet metal in which one part is superimposed on another part and stabilized by the superimposed state stabilization means, it is possible to perform die-cutting more accurately on the superimposed state strip-shaped sheet metal (die-cutting sheet metal), and the quality of the die-cut products obtained by the die-cutting process can be improved.

[0021] In the die-cutting plate manufacturing apparatus according to the present invention, it is preferable to further provide a crimping forming means for forming a crimp for fastening the one part and the other part together.

[0022] According to the die-cutting sheet metal manufacturing apparatus with this configuration, die-cutting is performed on a strip-shaped sheet metal that is fastened together by a crimping mechanism, which fastens one part to another. This allows for more accurate die-cutting of overlapping strip-shaped sheets (die-cutting sheet metal), thereby improving the quality of the die-cut products obtained.

[0023] Next, the characteristic configuration of the punching apparatus according to the present invention for solving the above problems is a punching apparatus that intermittently feeds a strip-shaped plate in its longitudinal direction and sequentially feeds the strip-shaped plate into a die to perform punching, and is equipped with an overlapping means that, before the strip-shaped plate is fed into the die, overlaps a part of the strip-shaped plate with another part of the strip-shaped plate.

[0024] In this punching apparatus, a portion of the strip is folded by a superposition mechanism before being fed into the die, causing it to overlap with other parts. The strip (punching material), now in this superposition state, is then sequentially fed into the die for punching. When punching is performed on the superposition strip, multiple punched products can be obtained simultaneously in a single punching operation. Therefore, the production efficiency of punching can be improved.

[0025] Furthermore, the characteristic configuration of the punching apparatus according to the present invention for solving the above problems is that it comprises a feeding means for feeding a punching sheet material having a superimposed structure in which a part of a strip-shaped plate to be punched is superimposed on another part, and a punching means for performing punching on the punching sheet material fed by the feeding means.

[0026] According to this punching apparatus configuration, a sheet material for punching, having a superimposed structure in which a portion of the strip to be punched is overlapped with other portions, is fed into the punching mechanism by a feeding mechanism and punching is performed. When punching is performed on a sheet material with a superimposed structure, multiple punched products can be obtained simultaneously in a single punching operation. Therefore, the production efficiency of punching can be improved.

[0027] Next, the characteristic configuration of the punching method according to the present invention for solving the above problems is a punching method in which a strip-shaped plate is intermittently fed in the longitudinal direction thereof, and the strip-shaped plate is sequentially fed into a die to perform punching, and the method includes a superposition step in which a part of the strip-shaped plate is superimposed on another part of the strip-shaped plate before it is fed into the die.

[0028] According to this punching method, in the overlapping process, a portion of the strip-shaped plate is superimposed on other portions of the strip-shaped plate (punching material), and punching is performed on the resulting overlapping strip-shaped plate. When punching is performed on the overlapping strip-shaped plate, multiple punched products can be obtained simultaneously in a single punching operation. Therefore, the production efficiency of punching can be improved.

[0029] Furthermore, the characteristic configuration of the punching method according to the present invention for solving the above problems is that it includes a feeding step of feeding a punching sheet material having a superimposed structure in which a part of a strip-shaped sheet to be punched is superimposed on other parts, and a punching step of performing punching on the punching sheet material fed by the feeding step.

[0030] According to this punching method, a sheet material for punching, having an overlapping structure in which a portion of the strip-shaped sheet to be punched is superimposed on other portions, is fed through a feeding process, and then punching is performed on the sheet material in the punching process. When punching is performed on a sheet material with an overlapping structure, multiple punched products can be obtained simultaneously in a single punching operation. Therefore, the production efficiency of punching can be improved.

[0031] Figure 1 is an explanatory diagram showing the overall configuration of the punching device of the first embodiment. Figure 2 is an explanatory diagram of the bending process of a strip plate by a bending device. Figure 3 is an explanatory diagram showing the overall configuration of the punching device of the second embodiment. Figure 4 is a view taken along the line A-A in Figure 3. Figure 5 is a view taken along the line B in Figure 3. Figure 6 is an explanatory diagram showing the overall configuration of the punching device of the third embodiment. Figure 7 is an explanatory diagram of the first roll forming section and the second roll forming section. Figure 8 is an explanatory diagram of the third roll forming section and the fourth roll forming section. Figure 9 is an explanatory diagram of the twisting device. Figure 10 is an explanatory diagram of another embodiment 1. Figure 11 is an explanatory diagram of another embodiment 2. Figure 12 is an explanatory diagram of another embodiment 3.

[0032] The present invention will be described below with reference to the drawings. In the following embodiments, a punching plate material, a punching plate material manufacturing apparatus, a punching apparatus, and a punching method applied to the manufacture of core pieces constituting the laminated core of an electric motor will be described as examples. However, the present invention is not intended to be limited to the embodiments and configurations described below or shown in the drawings. In Figures 1 to 12, the various devices constituting the punching apparatus of the present invention have been exaggerated or simplified as appropriate for the sake of ease of explanation, and do not strictly reflect the relative sizes and arrangements of the various devices in an actual punching apparatus. Also, in Figures 1 to 4, 6 to 9, 11, and 12, the thickness relationships of the strip plates have been exaggerated as appropriate for the sake of ease of understanding, and do not strictly reflect the relative sizes (scale) of the actual strip plates.

[0033] [First Embodiment] <Overall Configuration> Figure 1 is an explanatory diagram showing the overall configuration of a punching device 1A according to the first embodiment of the present invention. As shown in Figure 1, the punching device 1A includes an uncoiler 2, a leveler 3, a bending device 4, a holding device 5, a pinch roll device 6, and a press device 7. A crimping device 110 is disposed between the pinch roll device 6 and the press device 7. In this example, the punching sheet material manufacturing device 301 is mainly composed of the uncoiler 2, leveler 3, bending device 4, holding device 5, pinch roll device 6, and crimping device 110. The configuration including the bending device 4 and the holding device 5 corresponds to the "superposition means" of the present invention. Furthermore, the pinch roll device 6 corresponds to the "superposition state stabilization means" of the present invention, and the crimping device 110 corresponds to the "crimping means" of the present invention.

[0034] The uncoiler 2 consists of a drum 20 having a horizontal axis, which is supported on a support column 21 so as to be able to transmit rotational power from a motor (not shown). In this example, a coil material KA, which is made by winding a strip-shaped electromagnetic steel sheet 10 (hereinafter referred to as "strip-shaped plate 10") having a thickness of approximately 0.1 to 0.5 mm and a width of approximately 200 to 500 mm, is mounted on the drum 20 so as to align its horizontal axis with the horizontal axis of the drum 20. The strip-shaped plate 10 unwound from the coil material KA by the operation of the uncoiler 2 is fed to the leveler 3 with its plate surface facing up and down, with the feeding direction being from left to right in Figure 1.

[0035] The leveler 3 has a plurality of straightening rolls 30 arranged in a staggered pattern along the feeding direction of the strip plate 10, and straightens the strip plate 10 to improve its flatness by passing it between these straightening rolls 30.

[0036] Between the uncoiler 2 and the leveler 3, a loop portion LP is formed by bending the strip plate 10 on the side where the strip plate 10 is fed out from the coil material KA. The loop portion LP is provided to absorb the difference between the speed at which the strip plate 10 is unwound by the uncoiler 2 and the speed at which the strip plate 10 passes through the leveler 3. The rotation speed of the uncoiler 2 is controlled so that the lowest point of the strip plate 10 in the loop portion LP is always within a certain range, by detecting the position of the lowest point of the strip plate 10 with a sensor (not shown).

[0037] <Bending device> The bending device 4 includes a suction part 40 that can suction / not suction the strip-shaped plate 10, a lifting mechanism 41 that moves the suction part 40 in the vertical direction (Z-axis direction), and a Y-axis feed mechanism 42 that moves the lifting mechanism 41 together with the suction part 40 in the longitudinal direction (Y-axis direction) of the strip-shaped plate 10.

[0038] The suction part 40 of the bending device 4 is arranged to face the upper plate surface of the strip plate 10 sent out from the leveler 3, has a plurality of air intake ports (not shown) opened toward the upper plate surface of the strip plate 10, and has a suction port (not shown) communicating with these air intake ports. The suction port of the suction part 40 is connected to a vacuum tank maintained at a vacuum level of a certain level or more by a vacuum pump (not shown) via a pipe or the like (not shown). And the suction part 40 of the bending device 4 can be switched between a suction state for sucking the strip plate 10 and a non-suction state for not sucking the strip plate 10 according to an opening / closing signal from a control device (not shown) for an opening / closing valve (not shown) provided in the pipe between the suction port of the suction part 40 and the vacuum tank.

[0039] As the lifting mechanism 41 and the Y-axis feeding mechanism 42, for example, those mainly composed of a ball screw linear motion guide mechanism or a rack and pinion mechanism that uses an electric motor as a rotational drive source and converts the rotational power from the electric motor into linear power can be cited.

[0040] <Holding device> The holding device 5 includes a suction part 50 capable of sucking / non-sucking the strip plate 10 and a support base 51 that supports the suction part 50. The suction part 50 of the holding device 5 is arranged to face the lower plate surface of the strip plate 10 sent out from the leveler 3. As the suction part 50 of the holding device 5, one having basically the same configuration as the suction part 40 of the bending device 4 is used, and it can be switched between a suction state for sucking the strip plate 10 and a non-suction state for not sucking the strip plate 10 according to an opening / closing signal from a control device for an opening / closing valve provided in the pipe between the suction port of the suction part 50 and the vacuum tank.

[0041] <Pinch roll device> The pinch roll device 6 is arranged between the holding device 5 and the caulking forming device 110 and is installed on the gantry 60. This pinch roll device 6 includes a pinch roll 61 on one side (the upper side in FIG. 1) and a pinch roll 62 on the other side (the lower side in FIG. 1), and a pinch roll support 63 that supports this pair of pinch rolls 61, 62.

[0042] The pair of pinch rollers 61 and 62 both have a horizontal axis parallel to the horizontal axis of the drum 20, and are arranged so as to face each other in the plate thickness direction of the strip plate 10. While the pinch roller 61 can be brought into contact with the upper plate surface of the strip plate 10, the other pinch roller 62 can be brought into contact with the lower plate surface of the strip plate 10.

[0043] The pinch roller support 63 mainly comprises a casing 64 and a slider 65. The casing 64 has an accommodation space capable of accommodating the pair of pinch rollers 61 and 62 and the slider 65. The pinch roller 62 is rotatably supported by the casing 64. The slider 65 is attached to the casing 64 so as to be relatively movable with respect to the pinch roller 62 so as to approach or separate from the pinch roller 62.

[0044] The pinch roller 61 is rotatably supported by the slider 65. Further, the piston rod of an air cylinder 66 attached to the casing 64 is connected to the slider 65. When the air cylinder 66 is extended, the slider 65 is moved so that the pinch roller 61 approaches the pinch roller 62, and the upper and lower plate surfaces of the strip plate 10 can be sandwiched between the pair of pinch rollers 61 and 62. On the contrary, when the air cylinder 66 is contracted, the slider 65 is moved so that the pinch roller 61 moves away from the pinch roller 62, and the distance between the pinch roller 61 and the pinch roller 62 can be widened.

[0045] An electric motor (not shown) for outputting rotational power for rotating the pinch roller 62 so as to send out the strip plate 10 toward the caulking forming device 110 is attached to the casing 64, and power transmission means such as a winding transmission mechanism (not shown) is provided between the electric motor and the pinch roller 62, and the pinch roller 62 can be rotated in a predetermined rotational direction (the direction of the symbol R arrow in FIG. 1) by the operation of the electric motor.

[0046] <Crimping Forming Apparatus> The crimping forming apparatus 110 is positioned between the pinch roll apparatus 6 and the press apparatus 7 and is installed on a frame 111. The crimping forming apparatus 110 includes a casing 112 that is placed on the frame 111. Inside the casing 112, a die 113 is arranged so that a strip-shaped plate 10 (a punching material 100, described later) fed from the pinch roll apparatus 6 can be placed on it, and a punch holder 115 is provided to hold a punch 114 positioned above the die 113, facing the die 113. An air cylinder 116 is attached to the upper surface of the casing 112 to move the punch 114 up and down via the punch holder 115. The crimping forming apparatus 110 is configured to perform crimping on the strip-shaped plate 10 (a punching material 100, described later) by the cooperation of the punch 114 and the die 113 by operating the air cylinder 116 at a predetermined timing.

[0047] <Pressing device> The pressing device 7 includes a slide 71 that is supported on the main frame 70 so as to be able to move up and down and is driven up and down by a slide drive mechanism (not shown), and a bolster 72 that is positioned opposite the slide 71. The upper die 73a of the die (progressive die) 73 is attached to the lower surface of the slide 71, and the lower die 73b of the die 73 is attached to the upper surface of the bolster 72. In this way, the up and down movement of the slide 71 performs press processing (punching) on ​​the strip-shaped plate 10 (a plate material for punching, described later) that is placed between the upper die 73a and the lower die 73b of the die 73.

[0048] Although a detailed explanation with illustrations is omitted, the mold 73 is equipped with a plurality of processing units arranged along the feeding direction of the strip-shaped plate 10. In the mold 73, as the strip-shaped plate 10 is intermittently fed sequentially between the plurality of processing units in the feeding direction, predetermined locations are punched out at each processing unit, thereby forming it into a core piece for a laminated iron core.

[0049] In the mold 73, the processing unit on the upstream side in the feed direction is a processing unit for drilling pilot holes. This pilot hole drilling processing unit is configured to drill a pair of pilot holes on both side edges of the strip-shaped plate 10 in the short direction (a direction that intersects (perpendicular to) the longitudinal direction (feed direction) of the strip-shaped plate 10 and is parallel to the surface of the strip-shaped plate 10) each time the strip-shaped plate 10 is intermittently fed sequentially, so that a plurality of pilot holes can be drilled at predetermined intervals (corresponding to the amount the strip-shaped plate 10 is fed sequentially) in the longitudinal direction of the strip-shaped plate 10.

[0050] Each processing unit in the mold 73, other than the processing unit for drilling pilot holes, is equipped with an upper die (movable die) and a lower die (fixed die) that are suitable for punching predetermined locations on the strip-shaped plate 10, and are arranged to move relative to each other in the vertical direction. A punch and a die are fixed to the upper die and the lower die. When the strip-shaped plate 10, which is intermittently fed between the punch and the die, stops with the pilot holes drilled on both side edges in the width direction engaging with the pilot pins of each processing unit, the punching of predetermined locations, which is the responsibility of that processing unit, is performed by the relative movement of the punch and the die.

[0051] A punching method for manufacturing laminated iron cores using the punching apparatus 1A of the first embodiment, configured as described above, will now be explained.

[0052] (Coil Material Mounting Process) First, a coil material KA, which is a wound body of electromagnetic steel sheet (strip plate 10), is prepared and mounted on the drum 20 of the uncoiler 2. The strip plate 10, which is unfurled from the coil material KA by the operation of the uncoiler 2, is fed intermittently with its surface facing up and down, with the feeding direction being from left to right in Figure 1. It proceeds sequentially through the leveler 3, bending device 4, holding device 5, pinch roll device 6, crimping forming device 110 and press device 7, and finally, bone-like scrap material called skeleton, which remains after punching out the iron core pieces, is led out from the downstream side of the press device 7 in the feeding direction.

[0053] (Strip plate straightening process) The strip plate 10 fed into the leveler 3 passes between multiple straightening rolls 30 and is straightened to a flat state suitable for punching.

[0054] (Strip Plate Holding Process) With the feeding operation of the strip plate 10 stopped, the suction part 50 of the holding device 5 is set to a suction state to suction and hold the strip plate 10.

[0055] (Strip Plate Overlay Process) Figure 2 is an explanatory diagram of the bending process of the strip plate 10 by the bending device 4. First, as shown in Figure 2(a), the suction part 40 of the bending device 4 is set to a standby position. That is, the bending device 4, through the cooperation of the lifting mechanism 41 and the Y-axis feeding mechanism 42, positions the suction part 40 of the bending device 4 at a predetermined height above the upstream portion of the strip plate 10, with an intermediate portion having an area of ​​approximately the same size as the portion where the suction part 50 has been applied, using the portion where the suction part 50 of the holding device 5 has been applied as a reference.

[0056] Next, as shown in Figure 2(b), the bending device 4 lowers the suction part 40 to a position where it can adsorb the strip-shaped plate 10 by operating the lifting mechanism 41, and adsorbs the strip-shaped plate 10 with the suction part 40 in an adsorbed state. In the following description, the part of the strip-shaped plate 10 that is adsorbed by the suction part 40 of the bending device 4 will be referred to as "a part 11 on the rear side of the strip-shaped plate 10", the part of the strip-shaped plate 10 that is adsorbed by the suction part 50 of the holding device 5 will be referred to as "another part 12 on the strip-shaped plate 10", and the intermediate part between the part 11 on the rear side of the strip-shaped plate 10 and the other part 12 on the strip-shaped plate 10 will be referred to as "a part 13 on the front side of the strip-shaped plate 10".

[0057] Next, as shown in Figures 2(b) to 2(c), the bending device 4 moves the suction part 40 upward while advancing the strip-shaped plate 10 in the feeding direction, through the cooperation of the lifting mechanism 41 and the Y-axis feeding mechanism 42.

[0058] Next, as shown in Figures 2(c) to 2(d), the bending device 4, through the cooperation of the lifting mechanism 41 and the Y-axis feeding mechanism 42, moves the suction part 40 up and down as appropriate while advancing in the feeding direction of the strip plate 10, so that a portion 13 of the front part of the strip plate 10 is interposed between a portion 11 of the rear part of the strip plate 10 and the other part 12 of the strip plate 10, and positions the suction part 40 of the bending device 4 above the suction part 50 of the holding device 5 so that the portion 11 of the rear part of the strip plate 10 overlaps the other part 12 of the strip plate 10 in a plan view. As a result, the portion 13 of the front part of the strip plate 10 is sandwiched between the suction part 40 of the bending device 4 and the suction part 50 of the holding device 5, and the portion 11 of the rear part of the strip plate 10 and the other part 12 of the strip plate 10 face each other in the vertical direction.

[0059] Then, as shown in Figure 2(e), the bending device 4 lowers the suction part 40 by operating the lifting mechanism 41, thereby overlapping the rear part 11 of the strip-shaped plate 10 with the other part 12 of the strip-shaped plate 10, with the front part 13 of the strip-shaped plate 10 interposed between them. In this way, the rear part 11 of the strip-shaped plate 10 can be reliably bent so that it overlaps the other part 12 along the longitudinal direction of the strip-shaped plate 10, with the front part 13 of the strip-shaped plate 10 interposed between them, through the cooperation of the bending device 4 and the holding device 5. After this, the suction part 40 of the bending device 4 and the suction part 50 of the holding device 5 are both set to a non-suction state, and the lifting mechanism 41 and the Y-axis feeding mechanism 42 work together to set the suction part 40 of the bending device 4 to the standby position shown in Figure 2(a), making it possible to perform the next strip plate bending process. At the same time, the strip plate 10 is fed in the feeding direction by a predetermined feed amount, and the next strip plate bending process (see Figures 2(a) to (e)) is performed. In this way, by repeatedly performing the intermittent feeding operation of the strip plate 10 and the bending operation of the strip plate 10 when the strip plate 10 is stopped, a three-layered section is formed in which a part 11 on the rear side of the strip plate 10, a part 13 on the front side of the strip plate 10, and the other part 12 of the strip plate 10 are overlapped, so that it is continuous in the longitudinal direction of the strip plate 10. In this way, a die-cutting plate material 100 is formed having a superimposed structure in which a portion 13 on the front side of the strip-shaped plate 10 and a portion 11 on the rear side of the strip-shaped plate 10 are superimposed on the other portion 12 of the strip-shaped plate 10 in order.

[0060] (Superimposed state stabilization process) As shown in Figure 1, when the three-layered portion of the strip-shaped plate 10 in the punching plate material 100 is fed into the pinch roll device 6, the three-layered portion is firmly gripped by a pair of pinch rolls 61 and 62, and at the same time, it is fed to the crimping forming device 110 by the pair of pinch rolls 61 and 62. At this time, the three-layered portion of the strip-shaped plate 10 is firmly gripped by the pair of pinch rolls 61 and 62, so that a part 11 on the rear side of the strip-shaped plate 10, a part 13 on the front side of the strip-shaped plate 10, and the other part 12 of the strip-shaped plate 10 are superimposed in close contact, thereby stabilizing the superimposed state of the strip-shaped plate 10. In this way, the strip-shaped plate 10 (punching plate material 100) whose superimposed state has been stabilized by the pinch roll device 6 is subjected to the punching process described later, so that punching can be performed more accurately on the punching plate material 100, and the quality of the punched products obtained by punching can be improved.

[0061] (Crimping Forming Process) When the die-cutting sheet metal 100 is fed into the crimping forming device 110, the air cylinder 116 is activated at a predetermined timing, causing the punch 114 and die 113 to work together to crimp the die-cutting sheet metal 100. As a result, a portion 11 on the rear side, a portion 13 on the front side, and other portions 12 of the strip-shaped plate 10 are fastened together by crimping. In this way, the die-cutting process described later is performed on the die-cutting sheet metal 100 fastened together by the crimping formed by the crimping forming device 110, so that the die-cutting process can be performed more accurately on the die-cutting sheet metal 100, and the quality of the die-cut products obtained by the die-cutting process can be improved. The position where the crimp is formed on the die-cutting sheet metal 100 is not particularly limited as long as it is a part other than the part that will be punched out in the die-cutting process described later, but it is preferable that it be on either the left edge or the right edge or both edges in the direction of feeding the strip-shaped plate 10.

[0062] (Punching Process) In the press device 7, the punching sheet material 100, which has undergone the crimping process, is intermittently fed sequentially in a state where it is slightly floating above the die of each processing unit in the mold 73. During punching, it is lowered from the previously floating state and engages with the pilot holes of pilot pins (not shown) provided in the lower die of each processing unit. As a result, the punching sheet material 100 is positioned and stopped when the pilot holes engage with the pilot pins, and the required punching process is performed in that stopped state.

[0063] In the mold 73, punching is performed sequentially by multiple processing units. Specifically, when forming the rotor core piece, one shaft hole, multiple peripheral holes, and multiple magnet insertion holes are punched out. Once this punching is complete, the punching sheet material 100 rises again, and the pilot hole becomes disengaged from the pilot pin, allowing it to move in the forward direction (downstream in the feeding direction). The punching sheet material 100 moves so that the areas where the shaft hole and other holes have been punched out are located within the next processing unit. Next, in the processing unit, circular holes defining the outer diameter of the rotor core piece are punched out on the outside of each magnet insertion hole. In this way, the rotor core piece is punched out and collected in a stacked state.

[0064] When forming the stator core piece, an inner circumferential arc hole defining the inner diameter of the stator core piece, multiple slots along the inner circumferential arc hole, multiple arc holes along the outer diameter of the stator core piece, and multiple bolt holes located between predetermined arc holes are punched out. Once this punching is complete, the punching plate material 100 is raised again and moved so that the punched-out arc holes and other parts are positioned within the next processing unit. Next, in the processing unit, ear portions and the like are punched out to connect the inner circumferential edges of each arc hole (i.e., the outer circumferential arc holes defining the outer diameter of the stator core piece). Specifically, ear portions are punched out at the locations where bolt holes are formed (for example, three locations). In this way, these ear portions and the inner circumferential edges of each arc hole form an outer edge portion that defines the shape of the punched-out stator core piece. In this way, the stator core pieces are punched out and then recovered in a stacked state.

[0065] In the punching method using the punching device 1A of the first embodiment, the bending device 4 and the holding device 5 work together to bend the strip-shaped plate 10 before it is fed into the die 73, so that a portion 11 on the rear side of the strip-shaped plate 10 is superimposed on the other portion 12 of the strip-shaped plate 10, sandwiching a portion 13 on the front side of the strip-shaped plate 10. Thus, the strip-shaped plate 10, i.e., the punching material 100, formed so that the three superimposed portions (superimposed portions) are continuous in the longitudinal direction, is sequentially fed into the die 73 of the press device 7 for punching. When punching is performed on the three superimposed portions of the strip-shaped plate 10 in the punching material 100, three iron core pieces (punched products) can be obtained simultaneously in a single punching operation. Therefore, the production efficiency of punching can be improved.

[0066] Generally, the clearance (positional accuracy) between the upper die 73a and the lower die 73b of the die 73 requires higher precision as the thickness of the strip plate 10 decreases, which contributes to an increase in the manufacturing cost of the die 73. However, in the case of the die-cutting sheet material 100, the three overlapping sections of the strip plate 10 are continuous in the longitudinal direction, so the precision required is not as high as when there is only one strip plate 10. As a result, the manufacturing cost of the die 73 can be reduced.

[0067] In the case of the strip-shaped plate 10, since the three overlapping portions of the strip-shaped plate 10 are continuous in the longitudinal direction, the section modulus is increased and rigidity is improved compared to the case of a single strip-shaped plate 10. This not only makes it easier to feed, but also makes it possible to feed a strip-shaped plate 10 with a larger width (length in the shorter direction).

[0068] [Second Embodiment] Figure 3 is an explanatory diagram showing the overall configuration of the punching apparatus 1B according to the second embodiment of the present invention. In the second embodiment, components that are the same as or similar to those in the first embodiment are denoted by the same reference numerals in the figure, and their detailed explanation is omitted (the same applies to the third embodiment described later).

[0069] In the second embodiment of the punching apparatus 1B, a notch forming device 8 is positioned between the leveler 3 and the holding device 5, and a bending device 9 is attached to the holding device 5. In this example, the punching sheet material manufacturing apparatus 302 is mainly composed of an uncoiler 2, a leveler 3, a notch forming device 8, a holding device 5, a bending device 9, a pinch roll device 6, and a crimping device 110. The uncoiler 2, leveler 3, holding device 5, pinch roll device 6, crimping device 110, and press device 7 have basically the same configuration as in the first embodiment. The following description will focus on the configuration of the notch forming device 8 and the bending device 9. The configuration including the holding device 5, the notch forming device 8, and the bending device 9 corresponds to the "superimposition means" of the present invention.

[0070] <Cutting Forming Device> The cutting forming device 8, positioned between the leveler 3 and the holding device 5 in Figure 3, is a device known as a shearing cutter, which, for example, cuts the strip-shaped plate 10 by sandwiching it between an upper blade and a lower blade. It forms cuts 15 (see Figure 5(a)) on both sides of the strip-shaped plate 10 in the short direction, extending for a predetermined length in the short direction of the strip-shaped plate 10, at predetermined intervals in the longitudinal direction.

[0071] <Bending device> Figure 4 is a view taken along the line A-A in Figure 3. Figure 4(a) is a diagram of the state before bending, Figure 4(b) is a diagram of the state after one side of the strip-shaped plate 10 in the short direction has been bent, and Figure 4(c) is a diagram of the state after the other side of the strip-shaped plate 10 in the short direction has been further bent. As shown in Figure 4(a), the bending device 9 comprises a pair of bending arms 91 and 92, and an actuator (not shown) that rotates the pair of bending arms 91 and 92. Of the pair of bending arms 91 and 92, the bending arm 91 positioned on the left side in the feeding direction of the strip-shaped plate 10 (the direction perpendicular to the paper surface in Figure 4 from the reader side) has a contact portion that can contact a part 16 on the left side between adjacent longitudinal cuts 15 (see Figure 5(a)) formed on the left side of the strip-shaped plate 10 in the short direction (X-axis direction). Of the pair of folding arms 91 and 92, the folding arm 92 positioned on the right side in the feeding direction of the strip-shaped plate 10 has a contact portion that can contact a portion 17 on the right side between adjacent longitudinal cuts 15 (see Figure 5(a)) formed on the right side of the strip-shaped plate 10 in the short direction (X-axis direction). The pair of folding arms 91 and 92 are pivotally attached to the suction unit 50 so as to be rotatable between a standby position (see Figure 4(a)) in which each contact portion is positioned in an unfolded position along the X-axis direction and a folded position (see Figures 4(b) and (c)) in which each contact portion is positioned facing the suction surface of the suction unit 50. Examples of actuators that drive the rotation of the pair of folding arms 91 and 92 include geared motors, air cylinders, electric cylinders, hydraulic cylinders, etc.

[0072] Next, we will describe a punching method for manufacturing laminated iron cores using the punching apparatus 1B of the second embodiment, which is configured as described above. The coil material mounting process, strip plate straightening process, superimposed state stabilization process, crimping process, and punching process are basically the same as those described in the punching method for manufacturing laminated iron cores using the punching apparatus 1A of the first embodiment, so their explanations will be omitted. Below, we will describe the strip plate notch formation process, the strip plate holding process, and the strip plate superimposed process.

[0073] (Strip Plate Cutting Formation Process) As shown in Figure 3, the strip plate 10 is fed in the feeding direction at a predetermined feed amount (a feed amount resulting from multiple feeding operations, corresponding to the length of the left and right portions 16 and 17) and placed on the suction part 50 of the holding device 5. Then, with the feeding operation of the strip plate 10 stopped, the cutting forming device 8 sandwiches the strip plate 10 at the planned cutting position with the upper and lower blades and cuts it, forming a cut 15. In this way, by repeatedly performing the intermittent feeding operation of the strip plate 10 until the feed amount corresponding to the length of the left and right portions 16 and 17 is reached, and the operation of sandwiching the strip plate 10 with the upper and lower blades and cutting it to form a cut 15 when stopped, as shown in Figure 5(a), cuts 15 of a predetermined length (see Figure 5(a)) extending in the short direction of the strip plate 10 are formed on both sides of the strip plate 10 in the short direction, with a predetermined interval in the longitudinal direction of the strip plate 10.

[0074] Figure 5 is a view from arrow B in Figure 3. Figure 5(a) is a diagram of the state before bending, Figure 5(b) is a diagram of the state after one side of the strip-shaped plate 10 in the short direction has been bent, and Figure 5(c) is a diagram of the state after the other side of the strip-shaped plate 10 in the short direction has been further bent. Note that in Figures 5(b) and (c), in order to make it easier to see the bent state of one side and the other side of the strip-shaped plate 10 in the short direction, the left bending arm 91 is omitted in Figure 5(b), and the left and right bending arms 91 and 92 are omitted in Figure 5(c).

[0075] (Strip Plate Holding Process) As shown in Figures 4(a) and 5(a), with the feeding operation of the strip plate 10 stopped, the suction part 50 of the holding device 5 is set to a suction state to hold the intermediate portion 18 (hereinafter referred to as "other portion 18") between the left portion 16 and the right portion 17 of the strip plate 10.

[0076] (Strip Plate Overlay Process) Next, as shown in Figures 4(b) and 5(b), the bending device 9 rotates the bending arm 91, which is located on the left side in the direction of feeding the strip plate 10, by operating an actuator, and folds the left portion 16 of the strip plate 10 so that it overlaps with the other portion 18 of the strip plate 10. Next, after setting the left bending arm 91 to a standby position, as shown in Figures 4(c) and 5(c), the bending device 9 rotates the bending arm 92, which is located on the right side in the direction of feeding the strip plate 10, by operating an actuator, and folds the right portion 17 of the strip plate 10 so that it overlaps with the other portion 18 of the strip plate 10 with the left portion 16 of the strip plate 10 interposed between them. In this way, the left portion 16 and the right portion 17 of the strip plate 10 can be reliably folded so that they overlap with the other portion 18 along the shorter direction of the strip plate 10. Then, after setting the right bending arm 92 to a standby position, the suction part 50 of the holding device 5 is set to a non-suction state, making it possible to perform the next strip plate bending process, and the strip plate 10 is fed in the feeding direction at a predetermined feed amount to perform the next strip plate bending process (see Figures 4(a) to (c) and 5(a) to (c)). In this way, by repeatedly performing the intermittent feeding operation of the strip plate 10 until a feed amount corresponding to the length of the left and right portions 16 and 17 of the strip plate 10 is reached, and the bending operation of the strip plate 10 when the strip plate 10 is stopped (see Figures 4(a) to (c) and 5(a) to (c)), a triple-layered portion is formed in which the left portion 16 and the right portion 17 are superimposed on the other portion 18 of the strip plate 10 so as to be continuous in the longitudinal direction of the strip plate 10.

[0077] In the punching method using the punching device 1B of the second embodiment, the holding device 5, the notch forming device 8, and the bending device 9 work together to bend the strip-shaped plate 10 before it is fed into the die 73, so that a portion 17 on the right side of the strip-shaped plate 10 is superimposed on the other portion 18, sandwiching a portion 16 on the left side of the strip-shaped plate 10. Thus, the strip-shaped plate 10, i.e., the punching plate material 100, is formed so that the three superimposed portions (superimposed portions) of the strip-shaped plate 10, portions 16, 17, and the other portion 18 are continuous in the longitudinal direction, and is sequentially fed into the die 73 of the press device 7 for punching. When punching is performed on the three superimposed portions of the strip-shaped plate 10 in the punching plate material 100, three iron core pieces (punched products) can be obtained simultaneously in a single punching operation. Therefore, the production efficiency of punching can be improved.

[0078] Furthermore, in the punching device 1B of the second embodiment, similar to the punching method using the punching device 1A of the first embodiment, the three-layer overlapping portion of the strip plate 10 is continuous in the longitudinal direction, which makes it possible to reduce the manufacturing cost of the mold 73 and facilitate the feeding of the strip plate 10.

[0079] [Third Embodiment] Figure 6 is an explanatory diagram showing the overall configuration of the punching apparatus 1C according to the third embodiment of the present invention. As shown in Figure 6, the punching apparatus 1C includes an uncoiler 2, a leveler 3, a roll forming device 130, a twisting device 200, a pinch roll device 6, a crimping device 110, and a press device 7. In this example, the punching sheet material manufacturing apparatus 303 is mainly composed of the uncoiler 2, the leveler 3, the roll forming device 130, the twisting device 200, the pinch roll device 6, and the crimping device 110. The roll forming device 130 corresponds to the "superposition means" of the present invention.

[0080] <Roll Forming Apparatus> The roll forming apparatus 130 functions as a superposition means for folding a portion of the strip-shaped plate 10 (parts 102 and 103, described later) into a state where it overlaps with another portion (another portion 101, described later). The roll forming apparatus 130 comprises a first roll forming section 131, a second roll forming section 132, a third roll forming section 133, and a fourth roll forming section 134, which are arranged in order from the upstream side to the downstream side in the feeding direction of the strip-shaped plate 10. Rotational power from an electric motor (not shown) is distributed and transmitted evenly to these roll forming sections 131 to 134 via a power distribution transmission mechanism (not shown) consisting of a required connecting shaft and a reduction gear.

[0081] Figure 7 is an explanatory diagram of the first roll forming section 131 and the second roll forming section 132. Figure 7(a) shows the first roll forming section 131 as shown in Figure 6 C １ -C １ This is a view from the direction of the arrow. Figure 7(b) shows the second roll forming section 132 as shown in Figure 6 C ２ -C ２ This is a view from the direction of the arrow.

[0082] As shown in Figure 7(a), the first roll forming section 131 includes a support frame 141 having a pair of shaft support parts 141a arranged at a predetermined distance from each other on both the left and right sides in the feeding direction of the strip-shaped plate 10, and a first roll mold 142 rotatably supported by the pair of shaft support parts 141a. The first roll mold 142 includes a first upper forming roll 143 and a first lower forming roll 144, which are arranged vertically so as to be able to grip the strip-shaped plate 10 and feed it in its longitudinal direction. In this example, rotational power evenly distributed by the power distribution transmission mechanism is introduced to the first lower forming roll 144, so that the first lower forming roll 144 functions as a driving roll and the first upper forming roll 143 functions as a driven roll (the same applies to the second roll forming section 132, the third roll forming section 133, and the fourth roll forming section 134).

[0083] The first upper forming roll 143 has a truncated conical upper intermediate contact portion 143a that can contact the intermediate portion 101 in the short direction of the strip-shaped plate 10 (hereinafter referred to as "other portion 101"), a truncated conical upper left contact portion 143b that can contact a part 102 on the left side of the strip-shaped plate 10 in the short direction in the direction of its feed, and a truncated conical upper right contact portion 143c that can contact a part 103 on the right side of the strip-shaped plate 10 in the short direction in the direction of its feed.

[0084] The first lower forming roll 144 has a truncated cone-shaped lower intermediate contact portion 144a that can contact other parts 101 of the strip-shaped plate 10, a truncated cone-shaped lower left contact portion 144b that can contact a part 102 on the left side of the strip-shaped plate 10, and a truncated cone-shaped lower right contact portion 144c that can contact a part 103 on the right side of the strip-shaped plate 10.

[0085] In the first upper forming roll 143 and the first lower forming roll 144, the other portion 101 of the strip-shaped plate 10 is held between the upper intermediate contact portion 143a and the lower intermediate contact portion 144a, a portion 102 on the left side of the strip-shaped plate 10 is held between the upper left contact portion 143b and the lower left contact portion 144b, and a portion 103 on the right side of the strip-shaped plate 10 is held between the upper right contact portion 143c and the lower right contact portion 144c. Then, by driving the first lower forming roll 144 to rotate, the strip-shaped plate 10 is fed in its feeding direction, causing the left portion 102 of the strip-shaped plate 10 to bend upward at an obtuse angle relative to the other portion 101 of the strip-shaped plate 10, and the right portion 103 of the strip-shaped plate 10 to bend downward at an obtuse angle, thereby forming a wavy shape when viewed in its feeding direction.

[0086] As shown in Figure 7(b), the second roll forming section 132 includes a support frame 151 having a pair of axial support parts 151a arranged at a predetermined distance from each other on both the left and right sides in the feeding direction of the strip-shaped plate 10, and a second roll mold 152 rotatably supported by the pair of axial support parts 151a. The second roll mold 152 includes a second upper forming roll 153 and a second lower forming roll 154, which are arranged vertically so as to be able to grip the strip-shaped plate 10 and feed it in its longitudinal direction.

[0087] The second upper forming roll 153 has a shape similar to that of the first upper forming roll 143 (see Figure 7(a)) compressed in the direction of its roll axis, and, like the first upper forming roll 143, has an upper intermediate contact portion 153a, an upper left contact portion 153b, and an upper right contact portion 153c. The second lower forming roll 154 has a shape similar to that of the first lower forming roll 144 (see Figure 7(a)) compressed in the direction of its roll axis, and, like the first lower forming roll 144, has a lower intermediate contact portion 154a, a lower left contact portion 154b, and a lower right contact portion 154c.

[0088] In the second upper forming roll 153 and the second lower forming roll 154, the other portion 101 of the strip-shaped plate 10 is held between the upper intermediate contact portion 153a and the lower intermediate contact portion 154a, a portion 102 on the left side of the strip-shaped plate 10 is held between the upper left contact portion 153b and the lower left contact portion 154b, and a portion 103 on the right side of the strip-shaped plate 10 is held between the upper right contact portion 153c and the lower right contact portion 154c. The strip-shaped plate 10 is then fed in its feeding direction by the rotational drive of the second lower forming roll 154, causing a portion 102 on the left side of the strip-shaped plate 10 to bend upward at an acute angle relative to the other portion 101 of the strip-shaped plate 10, and a portion 103 on the right side of the strip-shaped plate 10 to bend downward at an acute angle, thereby forming a bellows-like shape when viewed in its feeding direction.

[0089] Figure 8 is an explanatory diagram of the third roll forming section 133 and the fourth roll forming section 134. Figure 8(a) shows the third roll forming section 133 as shown in Figure 6 C ３ -C ３ This is a view from the direction of the arrow. Figure 8(b) shows the fourth roll forming section 134 as shown in Figure 6 C ４ -C ４ This is a view from the direction of the arrow.

[0090] As shown in Figure 8(a), the third roll forming section 133 includes a support frame 161 having a pair of shaft support portions 161a arranged at a predetermined distance from each other on both the left and right sides in the feeding direction of the strip-shaped plate 10, and a third roll mold 162 rotatably supported by the pair of shaft support portions 161a. The third roll mold 162 includes a third upper forming roll 163 and a third lower forming roll 164, which are arranged vertically so as to be able to grip the strip-shaped plate 10 and feed it in its longitudinal direction.

[0091] The third upper forming roll 163 has a truncated conical upper intermediate contact portion 163a that can contact other parts 101 of the strip-shaped plate 10 and is formed by slightly compressing the upper intermediate contact portion 153a (see Figure 7(b)) of the second upper forming roll 153 in the direction of its roll axis, and a disc-shaped upper right contact portion 163c that can contact a part 103 on the right side of the strip-shaped plate 10.

[0092] The third lower forming roll 164 has a truncated conical lower intermediate contact portion 164a that can contact other parts 101 of the strip-shaped plate 10 and is formed by slightly compressing the lower intermediate contact portion 154a (see Figure 7(b)) of the second lower forming roll 154 in the direction of its roll axis, and a disc-shaped lower left contact portion 164b that can contact a part 102 on the left side of the strip-shaped plate 10.

[0093] In the third upper forming roll 163 and the third lower forming roll 164, the other portion 101 of the strip-shaped plate 10 is held between the upper intermediate contact portion 163a and the lower intermediate contact portion 164a, a portion 102 on the left side of the strip-shaped plate 10 is held between the upper intermediate contact portion 163a and the lower left contact portion 164b, and a portion 103 on the right side of the strip-shaped plate 10 is held between the lower intermediate contact portion 164a and the upper right contact portion 163c. Then, by driving the third lower forming roll 164 to rotate and feed the strip-shaped plate 10 in its feeding direction, the left portion 102 of the strip-shaped plate 10 is further bent so that it stands upright in the vertical direction relative to the other portion 101 of the strip-shaped plate 10, and the right portion 103 of the strip-shaped plate 10 is further bent so that it hangs down in the vertical direction, so that the left portion 102 and the right portion 103 are facing each other horizontally with the other portion 101 in between, forming an inverted N shape when viewed in the feeding direction of the strip-shaped plate 10.

[0094] As shown in FIG. 8(b), the fourth roll forming section 134 includes a support frame 171 having a pair of shaft support portions 171a disposed at a predetermined interval on both the left and right sides in the feeding direction of the strip plate 10, and a fourth roll die 172 rotatably supported by the pair of shaft support portions 171a. The fourth roll die 172 includes a fourth upper forming roll 173 and a fourth lower forming roll 174 that are vertically arranged so as to be able to send the strip plate 10 in its longitudinal direction while sandwiching it.

[0095] The fourth upper forming roll 173 has a truncated conical upper upper contact portion 173a that can contact the upper portion of the strip plate 10 bent in an inverted N shape, and a disk-shaped upper right contact portion 173b that can contact a part 103 on the right side of the strip plate 10.

[0096] The fourth lower forming roll 174 has a truncated conical lower lower contact portion 174a that can contact the lower portion of the strip plate 10 bent in an inverted N shape, and a disk-shaped lower left contact portion 174b that can contact a part 102 on the left side of the strip plate 10.

[0097] In the fourth upper forming roll 173 and the fourth lower forming roll 174, the upper and lower portions of the strip plate 10 bent in an inverted N shape are sandwiched by the upper upper contact portion 173a and the lower lower contact portion 174a, and a part 102 on the left side and a part 103 on the right side of the strip plate 10 are sandwiched by the lower left contact portion 174b and the upper right contact portion 173b. Then, by rotating and driving the fourth lower forming roll 174 to send the strip plate 10 in its feeding direction, a part 102 on the left side and a part 103 on the right side of the strip plate 10 are folded in a superimposed state with respect to another part 101 of the strip plate 10, and a punching plate material 100 having a superimposed structure in which the parts 102 and 103 on both the left and right sides are superimposed is formed with respect to another part 101 of the strip plate 10 facing the plate surface in the left and right directions in the feeding direction of the strip plate 10.

[0098] <Twisting device> FIG. 9 is an explanatory view of the twisting device 200. FIG. 9(a) is a view of the first twisting portion 210 constituting the twisting device 200 as viewed from the direction of the C ５ -C ５ arrow in FIG. 6. FIG. 9(b) is a view of the second twisting portion 220 constituting the twisting device 200 as viewed from the C in FIG. 6６ -C ６ This is a view from the direction of the arrow.

[0099] As shown in Figures 9(a) and (b), the twisting device 200 includes a first twisting section 210 that twists the die-cut sheet material 100 fed out from the fourth roll forming section 134 (see Figure 6) 45° clockwise when viewed in the feeding direction of the strip-shaped sheet 10, and a second twisting section 220 that further twists the die-cut sheet material 100 twisted in the first twisting section 210 45° clockwise.

[0100] As shown in Figure 9(a), the first twisting section 210 includes a support frame 211 having a pair of shaft support sections 211a arranged on both the left and right sides in the feeding direction of the strip plate 10, and a first guide section 213 rotatably supported by the pair of shaft support sections 211a via a pair of brackets 212. The first guide section 213 includes an upper inclined roller 214 and a lower inclined roller 215 arranged in an inclined state in the upper and lower stages, which are arranged to allow the die-cutting sheet material 100 fed from the fourth roll forming section 134 (see Figure 6) to be fed in the longitudinal direction of the strip plate 10 while gripping its surface at an angle of 45° clockwise when viewed in the feeding direction of the strip plate 10.

[0101] As shown in Figure 9(b), the second twisting section 220 includes a support frame 221 having a pair of axial support sections 221a arranged on both the left and right sides in the feeding direction of the strip plate 10, and a second guide section 223 rotatably supported by the pair of axial support sections 221a. The second guide section 223 includes an upper horizontal roller 224 and a lower horizontal roller 225 arranged horizontally parallel to each other vertically, so that the punching plate material 100 fed from the first guide section 213 (see Figure 9(a)) can be fed in the longitudinal direction of the strip plate 10 while gripping its upper and lower plate surfaces in a state where it is tilted 45° clockwise when viewed in the feeding direction of the strip plate 10, i.e., horizontally.

[0102] In the twisting device 200, the die-cut sheet material 100 fed from the fourth roll forming section 134 (see Figure 6) is twisted 45° clockwise in the direction of feeding the strip sheet 10 by the first twisting section 210, and then twisted another 45° by the second twisting section 220, for a total of 90° of twisting. This allows the die-cut sheet material 100 fed from the fourth roll forming section 134, with the left portion 102, the other portion 101, and the right portion 103 of the strip sheet 10 overlapping with their respective surface faces from left to right, to be fed to the pinch roll device 6 as die-cut sheet material 100 with the left portion 102, the other portion 101, and the right portion 103 overlapping with their respective surface faces from top to bottom.

[0103] Next, we will describe a punching method for manufacturing laminated iron cores using the punching device 1C of the third embodiment, which is configured as described above. The coil material mounting process, strip plate straightening process, superimposed state stabilization process, crimping process, and punching process are basically the same as those described in the punching method for manufacturing laminated iron cores using the punching device 1A of the first embodiment, so their explanations will be omitted. Below, we will describe the strip plate superimposing process and the punching plate material twisting process.

[0104] (Strip-shaped plate superposition process) As shown in Figure 7(a), the strip-shaped plate 10 fed from the leveler 3 (see Figure 6) to the first roll forming section 131 is bent in a wave-like shape when viewed in the feeding direction of the strip-shaped plate 10 by the cooperation of the first upper forming roll 143 and the first lower forming roll 144. A portion 102 on the left side is bent upward at an obtuse angle relative to the other portion 101, and a portion 103 on the right side is bent downward at an obtuse angle.

[0105] Next, as shown in Figure 7(b), the strip-shaped plate 10 fed from the first roll forming section 131 (see Figure 7(a)) to the second roll forming section 132 is further bent upwards by the cooperation of the second upper forming roll 153 and the second lower forming roll 154, so that a portion 102 on the left side forms an acute angle relative to the other portion 101, and a portion 103 on the right side forms an acute angle, so that it is formed into a bellows shape when viewed in the feeding direction of the strip-shaped plate 10.

[0106] Next, as shown in Figure 8(a), the strip-shaped plate 10 fed from the second roll forming section 132 (see Figure 7(b)) to the third roll forming section 133 is further bent so that a portion 102 on the left side stands vertically upright relative to the other portion 101, and a portion 103 on the right side hangs vertically downwards. These portions 102 and 103 are then positioned horizontally opposite each other with the other portion 101 in between, forming an inverted N shape in the feeding direction of the strip-shaped plate 10.

[0107] Next, as shown in Figure 8(b), the strip-shaped plate 10 fed from the third roll forming section 133 (see Figure 8(a)) to the fourth roll forming section 134 is folded so that a portion 102 on the left side and a portion 103 on the right side overlap with the other portion 101. In this way, a die-cutting plate material 100 is formed having an overlapping structure in which portions 102 and 103 on both the left and right sides of the strip-shaped plate 10 overlap with the other portion 101 of the strip-shaped plate 10, with the plate surface facing left and right in the feeding direction of the strip-shaped plate 10.

[0108] (Twisting process for die-cut sheet material) As shown in Figures 9(a) and (b), the die-cut sheet material 100, which has been fed from the fourth roll forming section 134 (see Figure 8(b)) to the twisting device 200, is twisted 45° clockwise in the direction of feeding the strip sheet 10 by the first twisting section 210, and then twisted another 45° clockwise by the second twisting section 220, resulting in a total twist of 90°. As a result, the die-cutting sheet material 100, which is fed out from the fourth roll forming section 134 with the left portion 102, the other portion 101, and the right portion 103 of the strip-shaped sheet 10 overlapping with their respective surface orientations facing left to right from left to right, is fed to the pinch roll device 6 as die-cutting sheet material 100 with the left portion 102, the other portion 101, and the right portion 103 of the strip-shaped sheet 10 overlapping with their respective surface orientations facing up to down from top to bottom.

[0109] In the punching method using the punching device 1C of the third embodiment, the strip plate 10 is folded by the roll forming device 130 before being fed into the die 73, so that a portion 102 on the left side, another portion 101, and a portion 103 on the right side of the strip plate 10 are superimposed. Thus, the strip plate 10, i.e., the punching material 100, is formed so that the three superimposed portions (superimposed portions) of the strip plate 10, portions 102, 103, and other portion 101 are continuous in the longitudinal direction. The strip plate 10 is then twisted by the twisting device 200 so that the left portion 102, the other portion 101, and the right portion 103 of the strip plate 10 are superimposed with their respective surface faces in the vertical direction from top to bottom, and is sequentially fed into the die 73 of the press device 7 via the pinch roll device 6 and the crimping device 110 to perform punching. When punching is performed on the triple-layered portion of the strip-shaped plate 10 in the punching sheet material 100, three iron core pieces (punched products) can be obtained simultaneously in a single punching operation. Therefore, the production efficiency of the punching process can be improved.

[0110] Furthermore, in the punching device 1C of the third embodiment, similar to the punching method using the punching device 1A of the first embodiment, the strip-shaped plate 10 has a configuration in which the three overlapping portions are continuous in the longitudinal direction, which makes it possible to reduce the manufacturing cost of the mold 73 and to facilitate the feeding of the strip-shaped plate 10.

[0111] Although the die-cutting sheet material, die-cutting sheet material manufacturing apparatus, die-cutting apparatus, and die-cutting method of the present invention have been described above based on several embodiments, the present invention is not limited to the configurations described in the above embodiments, and its configuration can be modified as appropriate without departing from the spirit of the invention. Specific alternative embodiments are as follows.

[0112] (Another Embodiment 1) Figure 10 is an explanatory diagram of another embodiment 1. In the punching device 1B of the second embodiment, the bending device 9 is provided with a pair of bending arms 91 and 92, and the bending operation of these bending arms 91 and 92 is shown to overlap a portion 17 on the right side of the strip-shaped plate 10 with another portion 18, sandwiching a portion 16 on the left side of the strip-shaped plate (see Figures 4 and 5), but it is not limited to this. For example, as shown in Figure 10(a), the bending device 9A may be provided with only a bending arm 92 located on the right side in the feeding direction of the strip-shaped plate 10 (or a pair of bending arms 91 and 92 may be provided, but the left bending arm 91 may not be operated), and the bending operation of the bending arm 92 may cause a portion 17 on the right side of the strip-shaped plate 10 to overlap with another portion 18. Furthermore, as shown in Figure 10(b), the bending device 9B may consist only of a bending arm 91 positioned on the left side in the feeding direction of the strip plate 10 (or it may consist of a pair of bending arms 91 and 92, but the right bending arm 92 may not be operated), and the bending operation of the bending arm 91 may cause a portion 16 on the left side of the strip plate 10 to overlap with the other portion 18. Then, a double-layered portion formed by overlapping the left portion 16 or the right portion 17 on the other portion 18 of the strip plate 10 is created so as to be continuous in the longitudinal direction of the strip plate 10, and the double-layered portion of the strip plate 10 is punched out by the press device 7.

[0113] In the first and second embodiments described above, the adsorption parts 40 and 50 used are exemplified as being configured to adsorb the strip-shaped plate 10 using negative pressure. However, the invention is not limited to these configurations. For example, the adsorption parts 40 and 50 may be composed of electromagnets, and by switching between energized and de-energized states, the adsorption state in which the strip-shaped plate 10 is adsorbed using the magnetic force of the electromagnets and the non-adsorption state in which the strip-shaped plate 10 is not adsorbed may be used. Furthermore, an appropriate combination of an adsorption part utilizing negative pressure and an adsorption part utilizing magnetic force may be used.

[0114] (Another Embodiment 2) Figure 11 is an explanatory diagram of another embodiment 2. In the above embodiments, examples were shown in which the die-cut sheet material manufacturing devices 301, 302, and 303 are arranged on a processing line set up for the press device 7, but the invention is not limited to this. As shown in Figures 11(a) and (b), there is also an embodiment in which the die-cut sheet material manufacturing devices 301, 302, and 303 are arranged independently of the processing line set up for the press device 7. In this case, as shown in Figure 11(a), the die-cut sheet material 100 fed out from the crimping forming device 110 in the die-cut sheet material manufacturing devices 301, 302, and 303 is wound into a coil shape by the recoiler 251 while a predetermined tension is applied to it by the tension roller 250, and is temporarily stored as a coil material KB which is the wound weight of the die-cut sheet material 100. As shown in Figure 11(b), the coil material KB is mounted on the drum 20 of the uncoiler 2 installed on the processing line set up for the press device 7 as needed, and the die-cut sheet material 100 fed out from the coil material KB by the operation of the uncoiler 2 is sequentially fed to the leveler 3 and the press device 7 to perform the strip sheet straightening process and the die-cutting process. Even in this embodiment 2, the same effects and advantages as in the above embodiments can be obtained. Note that the configuration including the uncoiler 2 and the leveler 3 corresponds to the "feeding means" of the present invention.

[0115] (Another Embodiment 3) Figure 12 is an explanatory diagram of another embodiment 3. In the above-described other embodiment 2, a predetermined tension is applied to the punched sheet material 100 sent out from the crimping forming device 110 in the punched sheet material manufacturing apparatus 301, 302, 303 by a tension roller 250, and the sheet material is wound into a coil shape by a recoiler 251 and temporarily stored as a coil material KB which is the wound weight of the punched sheet material 100. However, the invention is not limited to this. As shown in Figure 12(a), the punched sheet material 100 sent out from the crimping forming device 110 in the punched sheet material manufacturing apparatus 301, 302, 303 is cut into predetermined lengths by a cutting device 252, and the punched sheet material 100a cut to predetermined lengths is sequentially transported to a work pallet 254 by a transport means 253 including, for example, a robot arm or a conveyor, and stacked for temporary storage. As shown in Figure 12(b), a work pallet 254 loaded with die-cut sheet metal 100a cut to a predetermined length may be placed on a processing line set up for the press device 7 as needed, and the die-cut sheet metal 100a cut to a predetermined length may be sequentially fed to the press device 7 by a feeding means 255 including a work feeding device and a conveyor to perform the strip sheet straightening process and the die-cutting process.

[0116] In the above embodiments and other embodiments, examples were shown in which a strip made of electromagnetic steel sheet was used as the strip plate 10, but the invention is not limited to this, and a strip made of stainless steel, aluminum, or other metal materials can also be used.

[0117] The die-cut sheet material, die-cut sheet material manufacturing apparatus, die-cutting apparatus, and die-cutting method of the present invention can be used for die-cutting a large number of die-cut products from thin sheets, and are suitable for forming iron core pieces that constitute laminates such as rotor cores and stator cores of electric motors, for example.

[0118] 1A, 1B, 1C Punching device 2 Uncoiler (feeding means) 3 Leveler (feeding means) 4 Bending device (overlaying means) 5 Holding device (overlaying means) 6 Pinch roll device (overlaying state stabilization means) 7 Press device (punching means) 8 Cutting forming device (overlaying means) 9 Bending device (overlaying means) 10 Strip plate 73 Die 100 Punching plate material 110 Crimping forming device (crimping forming means) 130 Roll forming device 143, 144 Forming roll 153, 154 Forming roll 163, 164 Forming roll 173, 174 Forming roll 255 Feeding means 301-303 Punching plate material manufacturing device

Claims

1. A die-cutting sheet material having a superimposed structure in which a portion of the strip-shaped sheet to be die-cut is overlapped with other portions.

2. The die-cutting plate material according to claim 1, wherein the strip-shaped plate is wound in the longitudinal direction to form a coil.

3. A die-cutting plate manufacturing apparatus equipped with a superposition means for overlapping a portion of a strip plate to be die-cut with other portions.

4. The die-cutting plate manufacturing apparatus according to claim 3, wherein the overlapping means includes a holding device for holding the strip-shaped plate, and a bending device for bending the part of the strip-shaped plate so as to overlap the other part along the longitudinal direction of the strip-shaped plate.

5. The die-cutting plate manufacturing apparatus according to claim 3, wherein the overlapping means includes: a holding device for holding the strip-shaped plate; a notch forming device for forming notches extending in the short direction of the strip-shaped plate on the short-side portion of the strip-shaped plate at predetermined intervals in the longitudinal direction; and a bending device for folding the portion between adjacent notches in the longitudinal direction of the strip-shaped plate, taking the portion said to be the one part, so as to overlap the other portion along the short direction of the strip-shaped plate.

6. The die-cutting plate manufacturing apparatus according to claim 3, which includes a roll forming apparatus that overlaps a portion of the strip-shaped plate with another portion of the strip-shaped plate by forming rolls that hold the strip-shaped plate and feed it in the longitudinal direction thereof.

7. The die-cut sheet metal manufacturing apparatus according to any one of claims 3 to 6, further comprising superimposed state stabilization means for stabilizing the state in which the part is superimposed on the other part.

8. The die-cut sheet metal manufacturing apparatus according to any one of claims 3 to 6, further comprising a crimping forming means for forming a crimp for fastening the aforementioned portion and the aforementioned other portion.

9. A punching apparatus that intermittently feeds a strip-shaped plate in its longitudinal direction and sequentially feeds the strip-shaped plate into a die to perform punching, the punching apparatus comprising a superposition means that, before the strip-shaped plate is fed into the die, superimposes a portion of the strip-shaped plate onto another portion.

10. A punching apparatus comprising: a feeding means for feeding a punching sheet material having a superimposed structure in which a portion of a strip-shaped sheet to be punched is overlapped with other portions; and a punching means for performing punching on the punching sheet material fed by the feeding means.

11. A punching method in which a strip of material is intermittently fed in the longitudinal direction thereof, and the strip of material is sequentially fed into a die to perform punching, the punching method comprising a superposition step in which a portion of the strip of material is superimposed on another portion of the strip of material before it is fed into the die.

12. A punching method comprising: a feeding step of feeding a punching sheet material having a superimposed structure in which a portion of a strip-shaped sheet to be punched is overlapped with other portions; and a punching step of performing punching on the punching sheet material fed by the feeding step.

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