Method of pressing

Abstract

To provide a method of pressing that can reduce load that is generated in a die and a squeeze ring at the time of rotation of a laminate.SOLUTION: A method of pressing includes a step of punching an iron core piece 201 from a workpiece 200 using two pairs of lamination units 11A, 11B arrayed in a transportation direction X of the workpiece 200 that is intermittently transported. Each of the lamination units 11A, 11B is configured to be switchable between a lamination mode of forming a laminate 204 and a rotation mode of performing several times a rotation motion of rotating a die 31 and a squeeze ring 33 while a stripper 120 is separated from the workpiece 200, while the stripper 120 goes up and down several times. When the lamination unit 11A is set to the lamination mode, the lamination unit 11B is set to the rotation mode. Whereas, when the lamination unit 11A is set to the rotation mode, the lamination unit 11B is set to the lamination mode.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pressing method. [Background technology]

[0002] 2. Description of the Related Art Conventionally, iron cores such as rotor cores and stator cores for rotating electrical machines include a cylindrical laminate body in which a plurality of iron core pieces punched out from electromagnetic steel sheets are laminated. An electromagnetic steel sheet is formed into a strip shape by passing through a gap between two rolls and being rolled. The gap between the two rolls may not be constant in the axial direction of the rolls due to factors such as the parallelism of the two rolls and the load acting on each roll. In this case, the electromagnetic steel sheet passing through the gap will have thick and thin portions. In a laminate formed by stacking core pieces punched out from such electromagnetic steel sheets, the thick and thin portions of the core pieces overlap with each other. This causes the thickness of the laminate to vary depending on its circumferential position. In this case, the laminate will become eccentric, which may impair the performance of the rotating electric machine.

[0003] Patent Document 1 discloses an apparatus for rotary lamination of a laminate to suppress variations in thickness of the laminate. In rotary lamination, a laminate on which a predetermined number of iron core pieces are stacked is rotated in the circumferential direction, and then the next iron core piece is stacked on the laminate.

[0004] The device described in Patent Document 1 includes a lower die set having a die and an upper die set having a punch. The upper die set is provided so that it can be raised and lowered relative to the lower die set. The punch is raised and lowered relative to the die, thereby punching out core pieces from an electromagnetic steel sheet.

[0005] The lower die set is provided in communication with the die and includes a squeeze ring that holds the core pieces, and a rotation drive mechanism that rotates the die and squeeze ring together. A plurality of core pieces are sequentially stacked inside the squeeze ring to form a laminate.

[0006] The upper die set has a stripper plate that presses the electromagnetic steel sheet against the die, and a cam plate that switches between punching and blank striking of the iron core pieces by the punch. The cam plate is in contact with the base end face of the punch and is slidable in a direction perpendicular to the ascending and descending direction of the punch. As the cam plate slides, the punch is switched between a protruding state and a retracted state relative to the lower die set. This allows the punch to switch between punching the iron core piece and blank striking.

[0007] The device described in Patent Document 1 also includes two stacking stations aligned in the conveying direction of the electromagnetic steel sheets. Each stacking station includes the above-mentioned die, squeeze ring, and transfer drive mechanism.

[0008] At each lamination station, once a laminate is formed inside the squeeze ring, the punch is put into a blank punching state and the laminate is rotated in the circumferential direction by the rotating drive mechanism. Then, the punch is put into a punching state, and iron core pieces are stacked on the laminate. In this way, the rotational stacking of the laminate is carried out at each lamination station.

[0009] Furthermore, in this device, while one lamination station is performing a punching operation for the core pieces, the other lamination station stops the punching operation and rotates the laminate. By alternately performing the punching operation and the rotation operation at each of the two lamination stations, the production efficiency of the laminate is improved. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-205836 Summary of the Invention [Problem to be solved by the invention]

[0011] When the upper die set approaches the lower die set, the lower die set is pressed down by the stripper plate via the electromagnetic steel sheet, so that a load from the stripper acts on the die and squeeze ring via the electromagnetic steel sheet.

[0012] At each lamination station, the upper die set is raised and lowered multiple times relative to the lower die set until the rotation of the laminate is completed. Therefore, the rotation at each lamination station is performed regardless of whether a load from the stripper is acting on the die and squeeze ring. If the rotation is performed while a load is acting on the die and squeeze ring, the rotation of the die and squeeze ring may be hindered or a load may be placed on the transfer drive mechanism. For this reason, it is desirable to reduce the load acting on the die and squeeze ring when the laminate is rotated. [Means for solving the problem]

[0013] A press method for solving the above problem is a press method that uses two sets of stacking units lined up in the transport direction of a workpiece that is intermittently transported to punch out core pieces from the workpiece, wherein each of the stacking units is configured to be switchable between a stacking mode in which the core pieces are punched out of the workpiece using a die and a punch, and the core pieces are stacked inside a squeeze ring connected to the die to form a laminate, and a rotation mode in which, with the punch retracted from the workpiece, a stripper that presses the workpiece against the die when punching out the core pieces is separated from the workpiece, and a rotating body including the die and the squeeze ring is rotated multiple times while the stripper moves up and down multiple times; when the upstream stacking unit of the two sets of stacking units in the transport direction is set to the stacking mode, the downstream stacking unit in the transport direction is set to the rotation mode, and when the upstream stacking unit is set to the rotation mode, the downstream stacking unit is set to the stacking mode.

[0014] According to this method, in the lamination unit in lamination mode, a laminate is formed inside the squeeze ring. Then, when this lamination unit is switched to rotation mode, the laminate rotates in the circumferential direction together with the die and squeeze ring. Therefore, by repeatedly forming and rotating the laminate in the same lamination unit, laminates with different rotation phases are stacked.

[0015] In the rotation mode, the punch retreats away from the workpiece, preventing the punch from punching out the core pieces from the workpiece. The die and squeeze ring rotate while the stripper is away from the workpiece, i.e., while no load is acting on the die and squeeze ring from the stripper via the workpiece. Therefore, it is possible to prevent loads from acting on the die and squeeze ring when the laminate rotates.

[0016] Furthermore, in the rotation mode, the die and squeeze ring rotate multiple times while the stripper is away from the workpiece while the stripper is raised and lowered multiple times. That is, in the rotation mode, the die and squeeze ring rotate intermittently. Therefore, when rotating the die and squeeze ring to a desired rotation angle, the rotation angle per rotation can be set to an angle smaller than the desired rotation angle. This allows the laminate to rotate without increasing the interval between raising and lowering the punch or stopping the punch. Therefore, a decrease in the production efficiency of the laminate can be suppressed. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a cross-sectional view showing a press device according to one embodiment. [Figure 2] FIG. 2 is a schematic diagram showing a pressing process using the pressing device of one embodiment. [Figure 3] FIG. 3 is a cross-sectional view of the lower mold taken along line 3-3 in FIG. [Figure 4] FIG. 4 is a cross-sectional view of the lower mold taken along line 4-4 in FIG. [Figure 5] FIG. 5 is a cross-sectional view showing an upper mold according to an embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which a workpiece is pressed down by a stripper in a stacking unit in a stacking mode according to an embodiment. [Figure 7] FIG. 7 is a cross-sectional view showing a state in which core pieces are punched out from a workpiece in a stacked unit in a stacked mode according to one embodiment. [Figure 8] FIG. 8 is a cross-sectional view showing a state in which a rotating body is rotating in a stacked unit in a rotation mode according to one embodiment. [Figure 9] FIG. 9 is a cross-sectional view showing a state in which a workpiece is pressed down by a stripper in a stacking unit in a rotational mode according to an embodiment. [Figure 10] FIG. 10 is a timing chart showing the operation of the press device. DETAILED DESCRIPTION OF THE INVENTION

[0018] An embodiment of a press device will be described below with reference to FIGS. (Configuration of press device 10) As shown in Figures 1 and 2, the press device 10 is a progressive press device configured to perform multiple processes, such as a hole punching process and a punching process, within a single device on a strip-shaped workpiece 200 that is intermittently transported by a feeder (not shown).

[0019] 2, the workpiece 200 is subjected to a plurality of types of hole punching processes, and then to a punching process S1 or a punching process S2. The punching process S1 is performed upstream of the punching process S2 in the conveyance direction of the workpiece 200. In addition, between the punching processes S1 and S2, there is an idle process A in which the workpiece 200 is conveyed without being processed. In this embodiment, a series of die sets that are aligned in the conveyance direction of the workpiece 200 and perform a plurality of processes are arranged in two rows in the width direction of the workpiece 200, shifted by a predetermined pitch in the conveyance direction.

[0020] 1, a press device 10 punches out a plurality of core pieces 201 from a workpiece 200 such as an electromagnetic steel plate, and sequentially stacks the core pieces 201 to form a laminate 204. The laminate 204 is used, for example, as an iron core for a rotor core or a stator core of a rotating electrical machine.

[0021] Hereinafter, a description will be given of a press device 10 that punches out core pieces 201 to be used for the core of a stator core from a workpiece 200, as an example of the press device 10. First, the core pieces 201 punched out from the workpiece 200 by the press device 10 will be described.

[0022] As shown in Fig. 2, the core piece 201 is annular and has a central hole 202. The core piece 201 has a plurality of protrusions 203 that protrude outward in the circumferential direction. For example, three protrusions 203 are provided on the core piece 201 at 120° intervals in the circumferential direction. The core piece 201 has a shape that is three-fold symmetrical with the central axis as the axis of symmetry. In other words, the core piece 201 has a shape that matches its original shape when rotated 120° in the circumferential direction around the central axis.

[0023] The core pieces 201 are provided with a joint portion (not shown) that protrudes to one side in the stacking direction. The joint portion is formed by so-called dowel processing in a process prior to the punching processes S1 and S2. Two core pieces 201 adjacent to each other in the stacking direction are joined to each other by crimping their joint portions due to the concave-convex relationship.

[0024] 1, the press device 10 includes a lower die 20 and an upper die 80 that is movable up and down relative to the lower die 20. The upper die 80 is connected to a slide (not shown) that reciprocates in the up and down direction, so that it can be moved up and down relative to the lower die 20.

[0025] Hereinafter, the conveying direction of the workpiece 200 will be referred to as the conveying direction X, the width direction of the workpiece 200 will be referred to as the width direction Y, and the lifting direction of the upper mold 80 will be referred to as the lifting direction Z. The conveying direction X, the width direction Y, and the lifting direction Z are perpendicular to each other. The lifting direction Z coincides with the up-down direction.

[0026] (Configuration of lower die 20) The lower mold 20 has a rotating body 30 including a die 31 and a squeeze ring 33, a die holder 40, a rotation mechanism 60, and a positioning mechanism 70. The rotating body 30 is cylindrical overall. The die holder 40 accommodates the rotating body 30 so that the rotating body 30 can rotate. The rotation mechanism 60 has a function of rotating the rotating body 30 in the circumferential direction. The positioning mechanism 70 has a function of positioning the rotating body 30 in the circumferential direction.

[0027] (Configuration of Rotating Body 30) As shown in FIG. 3, the rotating body 30 has a die 31, a squeeze ring 33, and a first gear .

[0028] The die 31 is cylindrical and has a through hole 32. The through hole 32 has a shape corresponding to the outer edge of the core piece 201. The squeeze ring 33 is cylindrical and has a through hole 34. The squeeze ring 33 is provided directly below the die 31 and communicates with the die 31. The through hole 34 has a shape similar to but slightly smaller than the shape of the through hole 32.

[0029] 1, the squeeze ring 33 has a function of holding the core pieces 201 by pressing the outer peripheral surface of the core pieces 201. Inside the squeeze ring 33, a plurality of core pieces 201 are sequentially stacked to form a laminate 204.

[0030] 3, the first gear 35 is fixed to the end face of the squeeze ring 33 opposite to the die 31. The first gear 35 is annular and has a through hole 36. The through hole 36 is larger than each of the through holes 32 and 34. The outer circumferential surface of the first gear 35 is provided with a plurality of teeth (not shown).

[0031] A plurality of bushings 37 are provided on the underside of the rotor 30, more specifically, on the underside of the first gear 35. For example, three bushings 37 are provided on the underside of the first gear 35 at 120° intervals in the circumferential direction. The bushings 37 have positioning recesses 38 into which positioning pins 71, which will be described later, are inserted. The positioning recesses 38 are open downward. Each positioning recess 38 has a circular cross section.

[0032] (Configuration of die holder 40) As shown in FIGS. 1 and 3, the die holder 40 has an accommodating recess 41 that accommodates the rotating body 30, and a discharge port 42 that communicates with the accommodating recess 41 and through which the laminate 204 is discharged.

[0033] 3, the accommodating recess 41 opens to the upper surface of the die holder 40. The cross-sectional shape of the accommodating recess 41 is a circle having a diameter larger than the outer diameter of the rotor 30. A bearing (not shown) is provided between the inner peripheral surface of the accommodation recess 41 and the outer peripheral surface of the rotor 30. This allows the rotor 30 to rotate relative to the die holder 40.

[0034] The discharge port 42 communicates with the bottom of the accommodation recess 41 and opens to the lower surface of the die holder 40. The diameter of the opening of the discharge port 42 is larger than each of the through holes 32, 34, 36 of the rotor 30.

[0035] A belt conveyor 50 is provided below the discharge port 42 to transport the laminate 204 discharged from the discharge port 42 to the outside. The belt conveyor 50 extends in the width direction Y, for example.

[0036] (Configuration of rotation mechanism 60) 4, the rotation mechanism 60 has a motor 61, a control unit 62, a second gear 63, and a third gear 64. The control unit 62 controls the driving of the motor 61. The second gear 63 is connected to an output shaft of the motor 61. The third gear 64 meshes with the second gear 63.

[0037] The motor 61 is disposed inside the lower mold 20 with its output shaft facing upward. The control unit 62 controls the rotation and stopping of the motor 61 based on a signal relating to the number of times the upper mold 80 is raised and lowered.

[0038] The third gear 64 is disposed between the first gear 35 and the second gear 63. The third gear 64 meshes with the first gear 35 and the second gear 63, thereby transmitting the rotational motion of the second gear 63 to the first gear 35.

[0039] As the motor 61 rotates, the gears 63, 64, and 35 rotate, causing the die 31 and the squeeze ring 33 to rotate in the circumferential direction inside the die holder 40. As a result, the laminate 204 held inside the rotating body 30 rotates in the circumferential direction.

[0040] (Configuration of positioning mechanism 70) 3, the positioning mechanism 70 has a positioning pin 71 inserted into the positioning recess 38 of the bushing 37, an actuator 72 that moves the positioning pin 71 back and forth, and a connecting member 73 that connects the positioning pin 71 and the actuator 72. The positioning mechanism 70 is located below the rotating body 30 inside the lower mold 20.

[0041] The positioning pin 71 has a cylindrical shape extending in the lifting direction Z. The actuator 72 is provided at a position offset radially outward from the rotor 30 relative to the positioning pin 71, more specifically, at a position offset upstream of the positioning pin 71 in the conveying direction X. The actuator 72 is, for example, an air cylinder configured so that a piston rod can advance and retreat relative to a case. The piston rod of the actuator 72 faces upward. The advance and retreat direction of the piston rod coincides with the axial direction of the rotor 30, i.e., the lifting direction Z.

[0042] The connecting member 73 has an elongated shape that is long in the conveying direction X. The connecting member 73 has a first end 73a to which the positioning pin 71 is connected and a second end 73b to which the piston rod of the actuator 72 is connected. The first end 73a and the second end 73b are located on opposite sides of each other in the conveying direction X.

[0043] As the piston rod of the actuator 72 advances and retreats in the elevation direction Z, the positioning pin 71 advances and retreats in the elevation direction Z via the connecting member 73. As a result, the positioning pin 71 appears and retracts relative to the positioning recess 38. The positioning pin 71 is inserted into the positioning recess 38, thereby restricting the rotation of the first gear 35. As a result, the rotating body 30 is positioned in the circumferential direction. The positioning pin 71 is configured to be insertable into each of the multiple positioning recesses 38 depending on the position of the rotating body 30 in the circumferential direction.

[0044] (Upper die 80 configuration) As shown in Fig. 5, the upper die 80 has a punch holder 90, a punch plate 100, a punch 110, a stripper 120, and a retraction mechanism 130. The punch holder 90 is connected to a slide (not shown) of the press device 10. The punch plate 100 is connected to the underside of the punch holder 90. The stripper 120 is located below the punch plate 100 and is biased downward. The punch 110 passes through the punch plate 100 and the stripper 120. The retraction mechanism 130 is housed inside the punch holder 90.

[0045] (Configuration of punch holder 90) The punch holder 90 has a recess 91 , a plurality of first through holes 92 , a plurality of second through holes 93 , and a third through hole 94 .

[0046] The recess 91 opens to the upper surface at the center of the punch holder 90. The recess 91 houses a retraction mechanism 130. Each first through hole 92 penetrates the punch holder 90 in the lifting direction Z on the outer periphery side of the recess 91. The first through hole 92 receives an upper end of a fastener 123. The fastener 123 is fixed to the punch holder 90 at a lower part of the first through hole 92.

[0047] Each second through hole 93 penetrates the punch holder 90 in the lifting direction Z on a side closer to the outer periphery of the recess 91 than the first through hole 92. The second through hole 93 receives an upper end of a stripper bolt 125, which will be described later.

[0048] The third through-hole 94 extends in the lifting direction Z and opens to the bottom surface of the recess 91 and the lower surface of the punch holder 90. (Configuration of punch plate 100) The punch plate 100 has a holding hole 101 , a plurality of first insertion holes 102 , and a plurality of second insertion holes 103 .

[0049] The holding hole 101 penetrates the punch plate 100 in the lifting direction Z at the center of the punch plate 100. A punch 110 is disposed in the holding hole 101. Each first insertion hole 102 penetrates the punch plate 100 in the lifting direction Z on the outer circumferential side of the holding hole 101. A support pin 122, a fastener 123, and a spring 124, which will be described later, are inserted into the first insertion hole 102.

[0050] Each second insertion hole 103 penetrates the punch plate 100 in the lifting direction Z on the outer circumferential side of the retaining hole 101 relative to the first insertion hole 102. A part of a stripper bolt 125 is inserted into each second insertion hole 103.

[0051] (Punch 110 configuration) 1, the punch 110 is provided so as to be able to move up and down relative to the die 31 as the upper die 80 moves up and down. The punch 110 enters the inside of the die 31 as the upper die 80 moves down. As a result, the punch 110 punches out the core piece 201 from the workpiece 200 together with the die 31.

[0052] 5, a support pin 111 is connected to the upper end of the punch 110. The support pin 111 is housed inside the third through hole 94. A spring 112 that urges the support pin 111 upward is provided inside the third through hole 94. The punch 110 is urged upward by the spring 112 via the support pin 111.

[0053] (Configuration of stripper 120) The stripper 120 moves up and down in the lifting direction Z in accordance with the lifting and lowering of the punch 110. The stripper 120 has a function of pressing the workpiece 200 against the die 31 when the punch 110 punches out the core pieces 201.

[0054] The stripper 120 has, for example, a plate shape. The stripper 120 has an insertion hole 121 into which the punch 110 is inserted. The insertion hole 121 penetrates the stripper 120 in the lifting direction Z at the center of the stripper 120.

[0055] A plurality of support pins 122 and a plurality of stripper bolts 125 are connected to the upper surface of the stripper 120 . The upper end of each support pin 122 is inserted into the first insertion hole 102. The upper end of each support pin 122 faces the lower end of the fastener 123 inside the first insertion hole 102.

[0056] A coil spring 124 is provided inside the first insertion hole 102. The fastener 123 and the support pin 122 are inserted into the spring 124. The stripper 120 is biased downward by the spring 124.

[0057] The stripper bolt 125 is provided so as to be slidable against the inner surface of the second insertion hole 103 . (Configuration of the retraction mechanism 130) The retraction mechanism 130 has a switching unit 140 that switches between punching and blank punching of the core piece 201 by the punch 110 , and a drive unit 150 that rotates the switching unit 140 .

[0058] (Configuration of Switching Unit 140) The switching section 140 has a plate-shaped base plate 141 and a cylindrical support member 142 connected to the lower surface of the base plate 141. The base plate 141 closes the recess 91 of the punch holder 90.

[0059] The switching portion 140 has a cylindrical switching member 143 into which the support member 142 is inserted, and a plurality of pins 145 that face the lower surface of the switching member 143 . A bearing 146 is provided between the outer circumferential surface of the support member 142 and the inner circumferential surface of the switching member 143. Therefore, the switching member 143 is supported by the support member 142 so as to be rotatable.

[0060] The multiple pins 145 are provided at intervals from one another in the circumferential direction of the switching member 143. Each pin 145 penetrates the punch holder 90 on the outer circumferential side of the third through-hole 94. The upper end of each pin 145 is frustum-shaped. The lower end of each pin 145 is in contact with the upper surface of the punch 110.

[0061] 5, the lower surface of the switching member 143 is provided with a plurality of relief recesses 144 for accommodating the respective upper ends of the plurality of pins 145. Each relief recess 144 has a shape slightly larger than the shape of the upper end of the pin 145.

[0062] As described above, the punch 110 is biased upward, so that the upper end of each pin 145 is pressed against the lower surface of the switching member 143. Therefore, when the upper end of the pin 145 faces the relief recess 144 as a result of the rotation of the switching member 143, the upper end of the pin 145 retracts into the relief recess 144. This causes the punch 110 to retract upward.

[0063] A pinion gear 147 that protrudes toward the outer periphery is provided at the lower end of the switching member 143. The pinion gear 147 is provided, for example, at a portion of the switching member 143 in the circumferential direction.

[0064] (Configuration of driving unit 150) The drive unit 150 has a rack gear 151 that meshes with the pinion gear 147, and a linear actuator 152 that reciprocates the rack gear 151 in the width direction Y.

[0065] The actuator 152 has a plurality of guide blocks 153 fixed to the lower surface of the base plate 141. The plurality of guide blocks 153 are provided at intervals from one another in the width direction Y. The guide blocks 153 have accommodation grooves extending in the width direction Y.

[0066] The actuator 152 has guide rails 154 that are provided so as to be movable relative to the guide blocks 153. The guide rails 154 are housed in housing grooves of the guide blocks 153. The guide rails 154 are elongated and extend in the width direction Y.

[0067] A slider 155 is fixed to the lower surface of the guide rail 154. The slider 155 has an elongated shape extending in the width direction Y. A rack gear 151 is fixed to the lower surface of the slider 155.

[0068] An air cylinder (not shown) that reciprocates the slider 155 in the width direction Y is connected to an end of the slider 155 in the width direction Y. The reciprocation of the slider 155 by the air cylinder causes the switching member 143 to rotate via the rack gear 151 and the pinion gear 147.

[0069] The switching unit 140 rotates the switching member 143 using the drive unit 150, thereby switching the position of the switching member 143 between the contact position and the retracted position. When the switching member 143 is in the abutment position, the upper end of each pin 145 abuts against the lower surface of the switching member 143. At this time, a gap is provided between the upper surface of the punch 110 and the lower surface of the punch holder 90. When the switching member 143 is in the abutment position, the punch 110 is in a punching state where it can punch the workpiece 200.

[0070] When the switching member 143 is in the retracted position, the upper end of each pin 145 is retracted into the relief recess 144. At this time, the upper surface of the punch 110 and the lower surface of the punch holder 90 are in contact. When the switching member 143 is in the retracted position, the punch 110 is in an empty punching state in which it cannot punch the workpiece 200 even if the upper die 80 descends toward the lower die 20.

[0071] (Configuration of stacked unit 11) 1, the press device 10 is provided with two sets of stacking units 11 arranged side by side in the conveying direction X. Each stacking unit 11 has the same configuration.

[0072] Hereinafter, the two stacked units 11 located upstream in the conveying direction X may be referred to as stacked unit 11A, and the one located downstream in the conveying direction X may be referred to as stacked unit 11B, to distinguish between them.

[0073] The lamination unit 11 has a punch 110, a rotating body 30, a stripper 120, a rotation mechanism 60, a retraction mechanism 130, and a positioning mechanism 70. The lamination unit 11 is configured to be switchable between a lamination mode in which a laminate 204 is formed and a rotation mode in which the rotating body 30 is rotated.

[0074] In the lamination mode, the lamination unit 11 punches out the core pieces 201 from the workpiece 200 using the die 31 and the punch 110, and also stacks the core pieces 201 inside the squeeze ring 33 to form a laminate 204.

[0075] 6, in the stacking mode, the switching member 143 is in the contact position, so that the punch 110 is in a punching state. In the stacking mode, the rotating body 30 is positioned by the positioning mechanism 70. In the stacking mode, when the upper die 80 descends, the stripper 120 comes into contact with the workpiece 200 before the punch 110 does.

[0076] 7, when the upper die 80 further descends, the punch 110 enters the inside of the die 31, thereby punching out the core pieces 201 from the workpiece 200. At this time, the stripper bolt 125 and the punch plate 100 slide against each other, and the spring 124 is compressed. Therefore, the stripper 120 does not descend together with the upper die 80, and continues to press down on the workpiece 200.

[0077] 8, the stacking unit 11 in the rotation mode performs a rotation operation of rotating the rotating body 30 by the rotation mechanism 60 while the stripper 120 is away from the workpiece 200, multiple times while the stripper 120 moves up and down multiple times. More specifically, the stacking unit 11 in the rotation mode rotates the rotating body 30 by a predetermined rotation angle θ by the rotation mechanism 60 every time the stripper 120 moves away from the workpiece 200.

[0078] 9, in the rotation mode, the switching member 143 is in the retracted position, so that the punch 110 is in an idle state. In the rotation mode, the rotation of the rotating body 30 is not restricted by the positioning mechanism 70, that is, the rotation of the rotating body 30 is permitted.

[0079] In the press device 10 described above, when the lamination unit 11A is in the lamination mode, the lamination unit 11B is set to the rotation mode. Also, when the lamination unit 11A is in the rotation mode, the lamination unit 11B is set to the lamination mode.

[0080] Here, as described above, since the shape of the core pieces 201 has three-fold symmetry, in the one-time rotation mode, the laminated body 204 is set to rotate 120° in the circumferential direction by the rotation of the rotor 30. The number of core pieces 201 constituting the laminated body 204 formed in the one-time lamination mode is, for example, 30. Since the stripper 120 separates from the workpiece 200 30 times in the one-time rotation mode, the rotation angle θ per time in the rotation mode is set to, for example, 4° (=120° / 30).

[0081] Next, the operation of the press device 10 will be described with reference to FIG. First, the operation of the press device 10 when the lamination unit 11A is in the lamination mode and the lamination unit 11B is in the rotation mode will be described.

[0082] When the stacking unit 11A is in the stacking mode, the retraction mechanism 130 is OFF, i.e., the switching member 143 of the retraction mechanism 130 is in the abutting position. Therefore, the punch 110 is in a punching state. Also, at this time, the positioning mechanism 70 is ON, i.e., the positioning mechanism 70 restricts the rotation of the rotating body 30. Also, at this time, the rotation mechanism 60 is OFF, i.e., the rotation mechanism 60 does not rotate the rotating body 30.

[0083] On the other hand, when the stacking unit 11B is in the rotation mode, the retraction mechanism 130 is ON, i.e., the switching member 143 of the retraction mechanism 130 is in the retracted position. Therefore, the punch 110 is in an idle state. Also at this time, the positioning mechanism 70 is OFF, i.e., the rotation of the rotating body 30 is not restricted by the positioning mechanism 70. Also at this time, the rotation mechanism 60 is ON, i.e., the rotating body 30 is rotated by the rotation mechanism 60. However, the rotating body 30 is rotated while the stripper 120 is away from the workpiece 200. Therefore, while the stripper 120 is in contact with the workpiece 200, the rotation mechanism 60 is OFF, and the rotating body 30 stops rotating. In other words, in the rotation mode, the rotating body 30 rotates intermittently.

[0084] Although not shown in the drawings, in this embodiment, when one stacking unit 11 switches from the stacking mode to the rotational mode, there is a period during which both stacking units 11 are in the rotational mode. Also, when one stacking unit 11 switches from the rotational mode to the stacking mode, there is a period during which both stacking units 11 are in the stacking mode.

[0085] For example, when the stacking unit 11A switches from the stacking mode to the rotation mode, the stacking unit 11B has two rotation operations remaining before the end of the rotation mode. That is, the first two rotation operations of the stacking unit 11A in the rotation mode and the last two rotation operations of the stacking unit 11B in the rotation mode are performed simultaneously. During the period when these two rotation operations are performed, both the stacking unit 11A and the stacking unit 11B are in the rotation mode. Note that the stacking mode of the stacking unit 11B starts in the third stroke after the stacking mode of the stacking unit 11A ends.

[0086] Thereafter, when the lamination unit 11A switches from the rotation mode to the stacking mode, the lamination unit 11B has two punching operations remaining before the end of the stacking mode. That is, the first two punching operations in the stacking mode of the lamination unit 11A and the last two punching operations in the stacking mode of the lamination unit 11B are performed simultaneously. During the period in which these two punching operations are performed, both lamination units 11 are in the stacking mode. Note that the rotation mode of the lamination unit 11B starts in the third stroke after the end of the rotation mode of the lamination unit 11A.

[0087] This operation is repeated multiple times to form a laminate 204 in each lamination unit 11. The laminate 204 formed in each lamination unit 11 is discharged through the discharge port 42 and then transported to the outside by the belt conveyor 50.

[0088] The operation and effects of this embodiment will be described. (1) The press device 10 has two stacking units 11 arranged side by side in the conveying direction X, each of which includes a punch 110, a rotating body 30, a stripper 120, a rotation mechanism 60, and a retraction mechanism 130. Each of the stacking units 11 is configured to be switchable between a stacking mode and a rotation mode. In the stacking mode, the stacking unit 11 punches out core pieces 201 from a workpiece 200 using the die 31 and the punch 110, and stacks the core pieces 201 inside a squeeze ring 33 to form a laminate 204. In the rotation mode, the stacking unit 11 rotates the rotating body 30 using the rotation mechanism 60 while the stripper 120 is away from the workpiece 200, with the punch 110 retracted from the workpiece 200 by the retraction mechanism 130. The rotation operation in the rotation mode is performed multiple times while the stripper 120 moves up and down multiple times. When the stacking unit 11A is in the stacking mode, the stacking unit 11B is set to the rotation mode. When the stacking unit 11A is in the rotation mode, the stacking unit 11B is set to the stacking mode.

[0089] According to this configuration, in the lamination unit 11 in the lamination mode, the laminate 204 is formed inside the squeeze ring 33. Thereafter, the lamination unit 11 is switched to the rotation mode, and the laminate 204 rotates in the circumferential direction together with the rotating body 30. Therefore, the formation and rotation of the laminate 204 are repeatedly performed in the same lamination unit 11, and laminates 204 having mutually different rotation phases are stacked.

[0090] Here, in the rotation mode, the retraction mechanism 130 retracts the punch 110 in a direction away from the workpiece 200, so that the punch 110 does not punch out the iron core pieces 201 from the workpiece 200. Furthermore, the rotation of the rotating body 30 is performed while the stripper 120 is away from the workpiece 200, that is, while no load is acting on the die 31 and the squeeze ring 33 from the stripper 120 via the workpiece 200. Therefore, it is possible to suppress the application of a load to the die 31 and the squeeze ring 33 when the laminate 204 rotates.

[0091] Furthermore, in the rotation mode, the rotation of the rotor 30 while the stripper 120 is away from the workpiece 200 is performed multiple times while the stripper 120 moves up and down multiple times. That is, in the rotation mode, the rotation of the rotor 30 is performed intermittently. Therefore, when rotating the rotor 30 to a desired rotation angle, the rotation angle θ per rotation can be set to an angle smaller than the desired rotation angle. This allows the laminate 204 to be rotated without increasing the interval between the elevation of the punch 110 or stopping the punch 110. Therefore, a decrease in the production efficiency of the laminate 204 can be suppressed.

[0092] (2) In the rotation mode, the rotation mechanism 60 rotates the rotor 30 by a predetermined rotation angle θ each time the stripper 120 separates from the workpiece 200 . With this configuration, the rotation angle θ of the rotating body 30 per rotation in the rotation mode is constant, which makes it easy to control the rotation mechanism 60, more specifically, the motor 61 by the control unit 62.

[0093] (3) Each stacking unit 11 has a positioning mechanism 70 that is located below the rotating body 30 and that positions the rotating body 30 in the circumferential direction when switching from the rotation mode to the stacking mode. The positioning mechanism 70 has a positioning pin 71 that is inserted into a positioning recess 38 provided on the underside of the first gear 35, and an actuator 72 that moves the positioning pin 71 back and forth.

[0094] For example, if the circumferential position of the rotating body 30 is slightly deviated from the normal position when the rotation of the rotating body 30 is completed, the punch 110 and the die 31 will interfere with each other, making it difficult to punch out the core piece 201.

[0095] In this regard, according to the above configuration, when the rotation of the rotating body 30 in the rotation mode is completed, the rotating body 30 is positioned in the circumferential direction. Therefore, when punching out the core pieces 201 in the next stacking mode, the punch 110 enters the inside of the die 31 without interfering with the die 31. This allows the core pieces 201 to be punched out smoothly when switching from the rotation mode to the stacking mode.

[0096] (4) The actuator 72 is provided at a position offset radially outward from the rotor 30 relative to the positioning pin 71. The positioning mechanism 70 has a connecting member 73 that connects the positioning pin 71 and the actuator 72 together.

[0097] According to this configuration, the actuator 72 is located radially outward of the rotor 30 relative to the positioning pin 71. This makes it possible to prevent the laminate 204 ejected from the rotor 30 from interfering with the actuator 72.

[0098] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. The positioning pin 71 may be connected to the actuator 72 without the connecting member 73. In this case, since the actuator 72 is located directly below the positioning pin 71, it is desirable to select the actuator 72 having a shape and size that does not interfere with the stack 204 discharged from the rotating body 30.

[0099] The positioning mechanism 70 may be omitted from the press device 10. The rotation angle θ of the rotor 30 in the rotation mode does not have to be constant. The rotation angle θ of the rotor 30 in the first rotation mode and the rotation angles θ of the rotor 30 thereafter may be different from each other.

[0100] In the rotation mode, the rotating body 30 does not have to be rotated every time the stripper 120 separates from the workpiece 200. For example, in the rotation mode, the rotating body 30 may be rotated every time the stripper 120 separates from the workpiece 200 twice. In this case, the rotation angle θ of the rotating body 30 per rotation may be set to be larger than the rotation angle θ of this embodiment.

[0101] In the rotation mode, the rotation of the rotor 30 may be completed before the stripper 120 is raised and lowered 30 times. For example, by setting the rotation angle θ to θ=5°, the rotation of 120° may be completed when the stripper 120 is separated from the workpiece 200 24 times (=120 / 5).

[0102] The stripper 120 is provided in each of the stacking units 11A and 11B, but may be provided in common to both the stacking units 11A and 11B. In this case, in each of the stacking units 11A and 11B, the workpiece 200 is pressed against the die 31 by the common stripper 120 provided in the upper die 80.

[0103] In this embodiment, when switching between the stacking mode and the rotational mode, there is a period during which both stacking units 11 are in the stacking mode or the rotational mode, but such a period does not have to exist. That is, when one stacking unit 11 is in the stacking mode, the other stacking unit 11 may always be in the rotational mode, and when one stacking unit 11 is in the rotational mode, the other stacking unit 11 may always be in the stacking mode.

[0104] The first gear 35 may be omitted from the rotor 30, and a gear portion that meshes with the second gear 63 may be provided on the outer periphery of the squeeze ring 33. In this case, the bushing 37 is preferably provided on the lower surface of the squeeze ring 33.

[0105] The rotation mechanism 60 may transmit the rotational motion of the motor 61 to the rotating body 30 via a belt. The press device 10 can also be applied to punching out core pieces 201 having a shape with n-fold symmetry (n is a natural number of 2 or more). In this case, if the number of core pieces 201 stacked during one stacking mode is N (N is a natural number of 2 or more), the rotation angle θ per rotation in the rotation mode is preferably θ = 360 / nN.

[0106] The press device 10 may be used to punch out iron core pieces used in the iron core of a rotor core.

[0107] <Additional Notes> The above embodiment includes the configurations described in the following supplementary notes. [Appendix 1] A press device comprising: a cylindrical die on which workpieces to be intermittently transported are placed; a punch that is provided so as to be able to rise and fall relative to the die and that punches out iron core pieces from the workpiece together with the die; a squeeze ring that is provided in communication with the die and that holds the iron core pieces; and a stripper that rises and falls with the rise and fall of the punch and presses the workpiece against the die when punching out the iron core pieces, wherein two stacking units each having the punch, a rotating body including the die and the squeeze ring, the stripper, a rotation mechanism that rotates the rotating body in the circumferential direction of the die, and a retraction mechanism that retracts the punch in a direction away from the workpiece in the rise and fall direction of the punch are provided side by side in the transport direction of the workpiece, and each of the stacking units is provided with a stacking unit that is connected to the die. and a rotation mode in which, with the punch retracted from the work by the retraction mechanism, the rotation mechanism rotates the rotating body while the stripper is away from the work, and the rotation operation is performed multiple times while the stripper moves up and down multiple times. When the upstream stacking unit in the conveying direction of the two sets of stacking units is in the stacking mode, the downstream stacking unit in the conveying direction is set to the rotation mode, and when the upstream stacking unit is in the rotation mode, the downstream stacking unit is set to the stacking mode.

[0108] [Appendix 2] The press device according to [Appendix 1], wherein in the rotation mode, the rotation mechanism rotates the rotating body by a predetermined rotation angle each time the stripper separates from the workpiece.

[0109] [Appendix 3] A press apparatus as described in [Appendix 1] or [Appendix 2], wherein each of the two stacking units has a positioning mechanism located below the rotating body and which positions the rotating body in the circumferential direction when switching from the rotation mode to the stacking mode, and a positioning recess is provided on the underside of the rotating body, and the positioning mechanism has a positioning pin inserted into the positioning recess and an actuator which moves the positioning pin back and forth in the axial direction of the rotating body.

[0110] [Appendix 4] The actuator is provided at a position biased radially outward from the rotating body relative to the positioning pin, and the positioning mechanism has a connecting member that connects the positioning pin and the actuator. [Appendix 3] A press device as described in [Explanation of symbols]

[0111] 10...Pressing device 11, 11A, 11B...Stacked unit 30...rotating body 31...Die 33...Squeeze ring 38... Positioning recess 60...Rotation mechanism 70... Positioning mechanism 71...Locating pin 72...Actuator 73...Connecting member 110...Punch 120...Stripper 130...Evacuation mechanism 200...Work 201...Iron core piece 204...Laminate

Claims

[Claim 1] A press method for punching iron core pieces from a workpiece that is intermittently transported using two sets of stacked units arranged in a transport direction of the workpiece, comprising: Each of the laminated units is a stacking mode in which the core pieces are punched out of the workpiece by a die and a punch, and the core pieces are stacked inside a squeeze ring communicating with the die to form a laminate; a rotation mode in which, with the punch retracted from the workpiece, a rotation operation in which the die and the squeeze ring are rotated while a stripper that presses the workpiece against the die when punching out the iron core pieces is separated from the workpiece, is performed multiple times while the stripper moves up and down multiple times; When the stacking unit on the upstream side in the conveying direction of the two sets of stacking units is set to the stacking mode, the stacking unit on the downstream side in the conveying direction is set to the rotation mode, and when the stacking unit on the upstream side is set to the rotation mode, the stacking unit on the downstream side is set to the stacking mode. Pressing method.

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