Pressing method

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 Art

[0002] Conventionally, an iron core such as a rotor core or a stator core of a rotating electrical machine includes a cylindrical laminated body formed by laminating a plurality of core pieces punched from electrical steel sheets. An electrical steel sheet is formed into a strip shape by being rolled through a gap between two rolling rolls. The gap between the two rolling rolls may not be constant in the axial direction of the rolling rolls due to factors such as the parallelism of the two rolling rolls and the load acting on each rolling roll. In this case, the electrical steel sheet passing through the gap has portions with large plate thickness and portions with small plate thickness. In a laminated body in which core pieces punched from such an electrical steel sheet are laminated, the portions with large plate thickness and the portions with small plate thickness of the core pieces overlap each other. Therefore, the thickness of the laminated body varies depending on the circumferential position thereof. In this case, the laminated body becomes eccentric, which may impair the performance of the rotating electrical machine.

[0003] Patent Document 1 discloses an apparatus that performs rotational lamination of a laminated body to suppress thickness variation of the laminated body. In rotational lamination, after a laminated body formed by laminating a predetermined number of core pieces is rotated in the circumferential direction, the next core piece is laminated onto the laminated body.

[0004] The apparatus 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 as to be capable of moving up and down relative to the lower die set. Core pieces are punched from the electrical steel sheet as the punch moves up and down relative to the die.

[0005] The lower die set includes a squeeze ring that communicates with the die and holds the core pieces, and a rotational lamination drive mechanism that integrally rotates the die and the squeeze ring. Inside the squeeze ring, a laminated body is formed by sequentially laminating a plurality of core pieces.

[0006] The upper die set includes a stripper plate that presses the electromagnetic steel sheet against the die, and a cam plate that switches between punching out iron core pieces with a punch and dry punching. The cam plate is mounted to contact the base end surface of the punch and to slide in a direction perpendicular to the punch's vertical movement. As the cam plate slides, the punch switches between a protruding state and a retracted state relative to the lower die set. This allows the punch to switch between punching out iron core pieces and dry punching.

[0007] Furthermore, the apparatus described in Patent Document 1 includes two sets of stacking stations arranged in the direction of transport of the electrical steel sheet. Each stacking station has the die described above, a squeeze ring, and a shifting drive mechanism.

[0008] In each stacking station, once a stack is formed inside the squeeze ring, the punch enters a non-firing state, and the stack is rotated circumferentially by the shifting drive mechanism. Subsequently, the punch enters a punching state, and iron core pieces are stacked onto the stack. In this way, rotational stacking of the stack is performed in each stacking station.

[0009] Furthermore, in this device, while punching out iron core pieces is being performed in one stacking station, the punching operation is stopped in the other stacking station and the stacked material is rotated. By having the punching and rotation operations performed alternately in each of the two stacking stations, the production efficiency of the stacked material is increased. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] Japanese Patent Publication No. 2011-205836 [Overview of the project] [Problems that the invention aims to solve]

[0011] Incidentally, when the upper die set approaches the lower die set, the lower die set is pressed down by the stripper plate via the electrical steel sheet. As a result, a load from the stripper acts on the die and squeeze ring via the electrical steel sheet.

[0012] In each stacking station, the upper die set moves up and down multiple times relative to the lower die set before the stacking operation is complete. Therefore, the rotational operation in each stacking station is performed regardless of whether or not a load from the stripper is acting on the dies and squeeze rings. If the rotational operation is performed while a load is acting on the dies and squeeze rings, there is a risk that the rotation of the dies and squeeze rings will be hindered or that a load will be placed on the shift drive mechanism. For this reason, it is desirable to reduce the load placed on the dies and squeeze rings during the rotation of the stack. [Means for solving the problem]

[0013] A pressing method for solving the above problems is a pressing method for punching out iron core pieces from a workpiece using two sets of stacking units arranged in the transport direction of an intermittently transported workpiece, wherein each of the stacking units is configured to switch between a stacking mode in which the iron core pieces are punched out from the workpiece by a die and a punch and the iron core pieces are stacked inside a squeeze ring communicating with the die to form a laminate, and a rotation mode in which, with the punch retracted from the workpiece, a rotation operation is performed multiple times while the stripper that presses the workpiece against the die when punching out the iron core pieces is away from the workpiece, and the rotation operation is performed multiple times while the stripper moves up and down multiple times, wherein when the upstream stacking unit in the transport direction of the two sets of stacking units 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 mode, a laminate is formed inside the squeeze ring of the lamination unit. Subsequently, when this lamination unit enters rotation mode, the laminate rotates circumferentially together with the die and squeeze ring. As a result, the formation and rotation of the laminate are repeatedly performed within the same lamination unit, and laminates with different rotation phases are stacked together.

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

[0016] Furthermore, in rotation mode, the die and squeeze ring rotate while the stripper is away from the workpiece, and this rotation occurs multiple times during the multiple times the stripper moves up and down. In other words, in rotation mode, the die and squeeze ring rotate intermittently. Therefore, the rotation angle per rotation can be smaller than the desired rotation angle in order to rotate the die and squeeze ring to the desired rotation angle. This allows the laminate to be rotated without increasing the punch lifting interval or stopping the punch. Consequently, a decrease in the production efficiency of the laminate can be suppressed. [Brief explanation of the drawing]

[0017] [Figure 1] Figure 1 is a cross-sectional view showing a press apparatus according to one embodiment. [Figure 2] Figure 2 is a schematic diagram showing a pressing process using a press device according to one embodiment. [Figure 3] Figure 3 is a cross-sectional view of the lower mold along line 3-3 in Figure 2. [Figure 4] Figure 4 is a cross-sectional view of the lower mold along line 4-4 in Figure 2. [Figure 5] Figure 5 is a cross-sectional view illustrating an upper die according to an embodiment. [Figure 6] Figure 6 is a cross-sectional view illustrating a state where a work is pressed by a stripper in a lamination unit in a lamination mode according to an embodiment. [Figure 7] Figure 7 is a cross-sectional view illustrating a state where a core piece is punched from a work in a lamination unit in a lamination mode according to an embodiment. [Figure 8] Figure 8 is a cross-sectional view illustrating a state where a rotating body rotates in a lamination unit in a rotation mode according to an embodiment. [Figure 9] Figure 9 is a cross-sectional view illustrating a state where a work is pressed by a stripper in a lamination unit in a rotation mode according to an embodiment. [Figure 10] Figure 10 is a timing chart illustrating an operation of a press apparatus. DESCRIPTION OF EMBODIMENTS

[0018] Hereinafter, an embodiment of a press apparatus will be described with reference to Figures 1 to 10. (Configuration of Press Apparatus 10) As shown in Figures 1 and 2, the press apparatus 10 is a progressive press apparatus configured to perform a plurality of processes including a punching process and a blanking process on a belt-shaped work 200 intermittently conveyed by a feeder (not shown) within a single apparatus.

[0019] As shown in Figure 2, after a plurality of types of punching processes are performed on the work 200, a blanking process S1 or a blanking process S2 is performed. The blanking process S1 is performed on an upstream side of the work 200 in the conveying direction relative to the blanking process S2. Further, an idle process A, in which the work 200 is conveyed without being processed, exists between the blanking process S1 and the blanking process S2. In the present embodiment, a series of die sets that are arranged in the conveying direction of the work 200 and perform a plurality of processes are arranged in two rows in the width direction of the work 200 while being shifted by a predetermined pitch in the conveying direction.

[0020] As shown in Figure 1, the press device 10 punches out multiple core pieces 201 from a workpiece 200 such as an electrical steel sheet and sequentially stacks the core pieces 201 to form a laminate 204. The laminate 204 is used, for example, as the core of a rotor core or stator core of a rotating electric machine.

[0021] In the following, as an example of a press device 10, we will describe a press device 10 that punches out core pieces 201 used for the core of a stator core from a workpiece 200. First, we will describe the core pieces 201 that are punched out from the workpiece 200 by the press device 10.

[0022] As shown in Figure 2, the core piece 201 has an annular shape with a central hole 202. The core piece 201 has a plurality of protrusions 203 that project outward in the circumferential direction. For example, the core piece 201 has three protrusions 203 arranged at 120° intervals in the circumferential direction. The core piece 201 has a shape that is 3-fold symmetric with respect to its central axis. That is, when the core piece 201 is rotated 120° in the circumferential direction around its central axis, it retains the shape of its original core piece.

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

[0024] As shown in Figure 1, the press device 10 comprises a lower die 20 and an upper die 80 that is mounted to be vertically movable relative to the lower die 20. The upper die 80 is mounted to be vertically movable relative to the lower die 20 by being connected to a slide (not shown) that reciprocates in the vertical direction.

[0025] Hereafter, the transport direction of the workpiece 200 will be referred to as the transport direction X, the width direction of the workpiece 200 as the width direction Y, and the vertical direction of the upper die 80 as the vertical direction Z. The transport direction X, the width direction Y, and the vertical direction Z are orthogonal to each other. The vertical direction Z coincides with the up and down direction.

[0026] (Composition of lower mold 20) The lower die 20 includes a rotating body 30 containing 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 in shape as a whole. The die holder 40 rotatably houses the rotating body 30. The rotation mechanism 60 has the function of rotating the rotating body 30 in the circumferential direction. The positioning mechanism 70 has the function of positioning the rotating body 30 in the circumferential direction.

[0027] (Configuration of the rotating body 30) As shown in Figure 3, the rotating body 30 includes a die 31, a squeeze ring 33, and a first gear 35.

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

[0029] As shown in Figure 1, the squeeze ring 33 has the function of holding the core piece 201 by pressing its outer surface against it. Inside the squeeze ring 33, a laminate 204 is formed by sequentially stacking multiple core pieces 201.

[0030] As shown in Figure 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 in shape with 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] Multiple bushings 37 are provided on the lower surface of the rotating body 30, or more specifically, on the lower surface of the first gear 35. For example, three bushings 37 are provided on the lower surface of the first gear 35 at 120° intervals in the circumferential direction. Each bushing 37 has a positioning recess 38 into which a positioning pin 71, described later, is inserted. The positioning recess 38 opens downward. Each positioning recess 38 has a circular cross-section.

[0032] (Configuration of die holder 40) As shown in Figures 1 and 3, the die holder 40 has a receiving recess 41 for accommodating the rotating body 30 and an outlet 42 that communicates with the receiving recess 41 and through which the laminated body 204 is discharged.

[0033] As shown in Figure 3, the receiving recess 41 opens onto the upper surface of the die holder 40. The cross-sectional shape of the receiving recess 41 is circular, with a diameter larger than the outer diameter of the rotating body 30. A bearing (not shown) is provided between the inner surface of the receiving recess 41 and the outer surface of the rotating body 30. This allows the rotating body 30 to rotate relative to the die holder 40.

[0034] The discharge port 42 communicates with the bottom of the housing 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 the through holes 32, 34, and 36 of the rotating body 30.

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

[0036] (Configuration of the rotating mechanism 60) As shown in Figure 4, the rotating mechanism 60 includes a motor 61, a control unit 62, a second gear 63, and a third gear 64. The control unit 62 controls the drive of the motor 61. The second gear 63 is connected to the output shaft of the motor 61. The third gear 64 meshes with the second gear 63.

[0037] The motor 61 is positioned inside the lower mold 20 with its output shaft facing upwards. The control unit 62 controls the rotation and stopping of the motor 61 based on signals related to the number of times the upper mold 80 has been raised and lowered.

[0038] The third gear 64 is positioned between the first gear 35 and the second gear 63. By meshing with the first gear 35 and the second gear 63, the third gear 64 transmits 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 squeeze ring 33 to rotate circumferentially inside the die holder 40. This causes the laminate 204 held inside the rotating body 30 to rotate circumferentially.

[0040] (Configuration of positioning mechanism 70) As shown in Figure 3, the positioning mechanism 70 includes a positioning pin 71 inserted into a positioning recess 38 of the bush 37, an actuator 72 that moves the positioning pin 71 forward and backward, 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 is cylindrical in shape and extends in the vertical direction Z. The actuator 72 is positioned radially outward from the positioning pin 71 of the rotating body 30, more specifically, upstream of the positioning pin 71 in the transport direction X. The actuator 72 is, for example, an air cylinder configured so that a piston rod can move back and forth relative to the case. The piston rod of the actuator 72 is oriented upward. The direction of movement of the piston rod coincides with the axial direction of the rotating body 30, i.e., the vertical direction Z.

[0042] The connecting member 73 has an elongated shape in the transport 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 transport direction X.

[0043] As the piston rod of the actuator 72 moves back and forth in the vertical direction Z, the positioning pin 71 moves back and forth in the vertical direction Z via the connecting member 73. This causes the positioning pin 71 to move in and out of the positioning recess 38. When the positioning pin 71 is inserted into the positioning recess 38, the rotation of the first gear 35 is restricted. This positions the rotating body 30 in the circumferential direction. The positioning pin 71 is configured to be insertable into each of the multiple positioning recesses 38 depending on the circumferential position of the rotating body 30.

[0044] (Configuration of the upper 80 model) As shown in Figure 5, the upper die 80 includes 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 lower surface of the punch holder 90. The stripper 120 is located below the punch plate 100 and is biased downward. The punch 110 penetrates both 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 on the upper surface in the central part of the punch holder 90. The retraction mechanism 130 is housed in the recess 91. Each first through-hole 92 penetrates the punch holder 90 in the vertical direction Z on the outer circumference side of the recess 91. The upper end of the fastener 123 is housed in the first through-hole 92. The fastener 123 is fixed to the punch holder 90 at the lower part of the first through-hole 92.

[0047] Each second through-hole 93 penetrates the punch holder 90 in the vertical direction Z, on the outer circumference side of the recess 91, compared to the first through-hole 92. The upper end of the stripper bolt 125, which will be described later, is housed in the second through-hole 93.

[0048] The third through-hole 94 extends in the vertical direction Z and opens to the bottom surface of the recess 91 and the lower surface of the punch holder 90. (Composition 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 vertical direction Z at the center of the punch plate 100. The punch 110 is positioned in the holding hole 101. Each first insertion hole 102 penetrates the punch plate 100 in the vertical direction Z on the outer circumference 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 holes 102.

[0050] Each second insertion hole 103 penetrates the punch plate 100 in the vertical direction Z, on the outer circumference side of the holding hole 101, compared to the first insertion hole 102. A portion of the stripper bolt 125 is inserted into the second insertion hole 103.

[0051] (Composition of Punch 110) As shown in Figure 1, the punch 110 is provided to move up and down relative to the die 31 as the upper die 80 moves up and down. As the upper die 80 descends, the punch 110 enters the inside of the die 31. As a result, the punch 110 punches out the iron core piece 201 from the workpiece 200 together with the die 31.

[0052] As shown in Figure 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 is provided inside the third through hole 94 to bias the support pin 111 upward. The punch 110 is biased upward by the spring 112 via the support pin 111.

[0053] (Stripper 120 configuration) The stripper 120 moves up and down in the vertical direction Z in conjunction with the vertical movement of the punch 110. The stripper 120 has the function of pressing the workpiece 200 against the die 31 when the iron core piece 201 is punched out by the punch 110.

[0054] The stripper 120 is, for example, plate-shaped. 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 vertical direction Z at the center of the stripper 120.

[0055] Multiple support pins 122 and multiple 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-shaped 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 slidably mounted against the inner surface of the second insertion hole 103. (Configuration of the evacuation mechanism 130) The retraction mechanism 130 includes a switching unit 140 that switches between punching out the iron core piece 201 with the punch 110 and dry punching, and a drive unit 150 that rotates the switching unit 140.

[0058] (Configuration of the 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 section 140 includes a cylindrical switching member 143 into which the support member 142 is inserted, and a plurality of pins 145 facing 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 rotatably supported by the support member 142.

[0060] Multiple pins 145 are provided at intervals from each other in the circumferential direction of the switching member 143. Each pin 145 penetrates the punch holder 90 on the outer circumference side of the third through hole 94. The upper end of each pin 145 is frustoconical in shape. The lower end of each pin 145 is in contact with the upper surface of the punch 110.

[0061] As shown by the dashed line in Figure 5, the lower surface of the switching member 143 is provided with multiple relief recesses 144 that accommodate the upper ends of each of the multiple pins 145. Each relief recess 144 is slightly larger than the shape of the upper end of the pin 145.

[0062] As described above, the punch 110 is biased upward, so the upper end of each pin 145 is pressed against the lower surface of the switching member 143. Therefore, when the switching member 143 rotates and the upper end of the pin 145 faces the relief recess 144, 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 is provided at the lower end of the switching member 143, protruding outward. The pinion gear 147 is provided, for example, on a portion of the switching member 143 in the circumferential direction.

[0064] (Configuration of the drive unit 150) The drive unit 150 includes 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 spaced apart from each other in the width direction Y. The guide blocks 153 have a receiving groove that extends in the width direction Y.

[0066] The actuator 152 has a guide rail 154 that is movable relative to the guide block 153. The guide rail 154 is housed in a housing groove of each guide block 153. The guide rail 154 is elongated and extends in the width direction Y.

[0067] A slider 155 is fixed to the underside of the guide rail 154. The slider 155 is elongated and extends in the width direction Y. A rack gear 151 is fixed to the underside of the slider 155.

[0068] An air cylinder (not shown) is connected to the end of the slider 155 in the width direction Y, causing the slider 155 to reciprocate in the width direction Y. The reciprocating motion of the slider 155 by the air cylinder is configured to cause 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 a contact position and a retracted position. When the switching member 143 is in the contact position, the upper ends of each pin 145 contact 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 contact position, the punch 110 becomes ready to punch out the workpiece 200.

[0070] When the switching member 143 is in the retracted position, the upper ends of each pin 145 retract 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 enters a state of no punching, where it is unable to punch the workpiece 200 even when the upper die 80 descends toward the lower die 20.

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

[0072] Hereafter, the stacking unit 11 located upstream in the transport direction X will be referred to as stacking unit 11A, and the stacking unit 11 located downstream in the transport direction X will be referred to as stacking unit 11B to distinguish between them.

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

[0074] In the lamination mode, the lamination unit 11 punches out iron core pieces 201 from the workpiece 200 using the die 31 and punch 110, and forms a laminated body 204 by laminating the iron core pieces 201 inside the squeeze ring 33.

[0075] As shown in Figure 6, in the stacking mode, the position of the switching member 143 is the contact position, so the punch 110 is in the 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 is lowered, the stripper 120 contacts the workpiece 200 before the punch 110.

[0076] As shown in Figure 7, as the upper die 80 descends further, the punch 110 enters the die 31, punching out the iron core piece 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. As a result, the stripper 120 does not descend with the upper die 80, but remains in place, holding down the workpiece 200.

[0077] As shown in Figure 8, in rotation mode, the stacking unit 11 rotates the rotating body 30 using the rotating mechanism 60 while the stripper 120 is away from the workpiece 200, and this rotation is performed multiple times while the stripper 120 moves up and down multiple times. More specifically, in rotation mode, the stacking unit 11 rotates the rotating body 30 by a predetermined rotation angle θ using the rotating mechanism 60 each time the stripper 120 moves away from the workpiece 200.

[0078] As shown in Figure 9, in rotation mode, the switching member 143 is in the retracted position, so the punch 110 is in a non-firing state. In 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 stacking unit 11A is in stacking mode, the stacking unit 11B is set to rotation mode. Also, when the stacking unit 11A is in rotation mode, the stacking unit 11B is set to stacking mode.

[0080] As described above, since the shape of the core piece 201 is three-fold symmetric, in one rotation mode, the rotation of the rotating body 30 causes the laminate 204 to rotate 120° in the circumferential direction. Also, the number of core pieces 201 constituting the laminate 204 formed in one lamination mode is, for example, 30. Since the stripper 120 moves away from the workpiece 200 30 times in one rotation mode, the rotation angle θ per rotation 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 Figure 10. First, we will describe the operation of the press device 10 when the stacking unit 11A is in stacking mode and the stacking unit 11B is in rotation mode.

[0082] When the lamination unit 11A is in lamination mode, the retraction mechanism 130 is OFF, meaning the switching member 143 of the retraction mechanism 130 is in the contact position. Therefore, the punch 110 is in the punching state. At this time, the positioning mechanism 70 is ON, meaning the rotation of the rotating body 30 is restricted by the positioning mechanism 70. At this time, the rotation mechanism 60 is OFF, meaning that the rotation of the rotating body 30 by the rotation mechanism 60 is not performed.

[0083] On the other hand, when the stacking unit 11B is in rotation mode, the retraction mechanism 130 is ON, meaning the switching member 143 of the retraction mechanism 130 is in the retracted position. Therefore, the punch 110 is in a non-firing state. Also at this time, the positioning mechanism 70 is OFF, meaning 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, meaning the rotation of the rotating body 30 is performed by the rotation mechanism 60. However, the rotation of the rotating body 30 is performed 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 rotation of the rotating body 30 stops. In other words, in rotation mode, the rotating body 30 rotates intermittently.

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

[0085] For example, when the lamination unit 11A switches from lamination mode to rotation mode, the lamination unit 11B has two rotational movements remaining before the end of its rotation mode. That is, the first two rotational movements of the lamination unit 11A in rotation mode and the last two rotational movements of the lamination unit 11B in rotation mode are performed simultaneously. During the period in which these two rotational movements are performed, both the lamination unit 11A and the lamination unit 11B are in rotation mode. The lamination mode of the lamination unit 11B starts three strokes after the lamination mode of the lamination unit 11A has ended.

[0086] Subsequently, when the lamination unit 11A switches from rotation mode to lamination mode, the lamination unit 11B has two punching operations remaining before the end of the lamination mode. That is, the first two punching operations in the lamination mode of the lamination unit 11A and the last two punching operations in the lamination 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 lamination mode. The rotation mode of the lamination unit 11B starts on the third stroke after the rotation mode of the lamination unit 11A ends.

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

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

[0089] In this configuration, in the stacking mode, the stacked body 204 is formed inside the squeeze ring 33 of the stacking unit 11. Subsequently, when the stacking unit 11 enters rotation mode, the stacked body 204 rotates circumferentially together with the rotating body 30. As a result, the formation and rotation of the stacked body 204 are repeatedly performed in the same stacking unit 11, and stacked bodies 204 with different rotation phases are stacked together.

[0090] In the rotation mode, the retraction mechanism 130 retracts the punch 110 away from the workpiece 200, so that the iron core piece 201 is not punched out of the workpiece 200 by the punch 110. Furthermore, the rotation of the rotating body 30 occurs while the stripper 120 is away from the workpiece 200, that is, while no load is acting on the die 31 and squeeze ring 33 via the workpiece 200 from the stripper 120. Therefore, it is possible to suppress the application of load to the die 31 and squeeze ring 33 when the laminate 204 is rotated.

[0091] Furthermore, in rotation mode, the rotation of the rotating body 30 occurs multiple times while the stripper 120 is away from the workpiece 200, during which the stripper 120 moves up and down multiple times. In other words, in rotation mode, the rotation of the rotating body 30 is performed intermittently. Therefore, in order to rotate the rotating body 30 to the desired rotation angle, the rotation angle θ per rotation can be made smaller than the desired rotation angle. This makes it possible to rotate the laminate 204 without increasing the lifting interval of the punch 110 or stopping the punch 110. Consequently, a decrease in the production efficiency of the laminate 204 can be suppressed.

[0092] (2) In rotation mode, each time the stripper 120 separates from the workpiece 200, the rotation mechanism 60 rotates the rotating body 30 by a predetermined rotation angle θ. With this configuration, the rotation angle θ of the rotating body 30 per rotation in rotation mode remains constant. Therefore, the rotation mechanism 60, and more specifically the motor 61 controlled by the control unit 62, can be easily controlled.

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

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

[0095] In this regard, with the above configuration, when the rotation of the rotating body 30 in rotation mode is completed, the circumferential positioning of the rotating body 30 is performed. Therefore, when punching out the iron core pieces 201 in the next lamination mode, the punch 110 enters the inside of the die 31 without interfering with the die 31. As a result, the punching out of the iron core pieces 201 when switching from rotation mode to lamination mode is performed smoothly.

[0096] (4) The actuator 72 is positioned radially outward relative to the positioning pin 71 of the rotating body 30. The positioning mechanism 70 has a connecting member 73 that connects the positioning pin 71 and the actuator 72.

[0097] With this configuration, the actuator 72 is located radially outward from the rotating body 30 compared to the positioning pin 71. Therefore, interference between the laminated material 204 ejected from the rotating body 30 and the actuator 72 can be suppressed.

[0098] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. The positioning pin 71 may be connected to the actuator 72 without going through the connecting member 73. In this case, since the actuator 72 is located directly below the positioning pin 71, it is desirable to select an actuator 72 that has a shape and size that does not interfere with the laminated body 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 rotating body 30 in rotation mode does not have to be constant. The rotation angle θ of the rotating body 30 for the first time in a single rotation mode may be different from the rotation angle θ of the rotating body 30 in subsequent rotations.

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

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

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

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

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

[0105] The rotating 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 when punching out iron core pieces 201 that have a shape that is n times symmetric (where n is a natural number of 2 or more). In this case, if the number of iron core pieces 201 stacked during one stacking mode is N (where N is a natural number of 2 or more), then the rotation angle θ per rotation in the rotation mode is preferably θ = 360 / nN.

[0106] The press device 10 may be applied to punching out core pieces used for the core of a rotor core.

[0107] <Note> The above embodiment includes the configuration described in the following appendix. [Note 1] A press apparatus comprising: a cylindrical die on which intermittently conveyed workpieces are arranged; a punch mounted to be vertically movable relative to the die and punching out an iron core piece from the workpiece together with the die; a squeeze ring provided in communication with the die and holding the iron core piece; and a stripper that moves up and down in accordance with the movement of the punch and presses the workpiece against the die when punching out the iron core piece, wherein two sets of stacking units are provided side by side in the direction of conveying the workpiece, each having a punch, a rotating body including the die and the squeeze ring, the stripper, a rotating mechanism for rotating the rotating body in the circumferential direction of the die, and a retraction mechanism for retracting the punch away from the workpiece in the vertical direction of the punch, and each of the stacking units is the same as the die A press device configured to switch between a lamination mode, in which the iron core pieces are punched out from the workpiece by the punch and the iron core pieces are stacked inside the squeeze ring to form a laminate, and a rotation mode, in which the punch is retracted from the workpiece by the retraction mechanism and the rotation operation in which the rotating body is rotated by the rotation mechanism while the stripper is away from the workpiece, and the rotation operation is performed multiple times while the stripper moves up and down multiple times, wherein when the upstream lamination unit in the transport direction of the two sets of lamination units is in lamination mode, the downstream lamination unit in the transport direction is set to rotation mode, and when the upstream lamination unit is in rotation mode, the downstream lamination unit is set to lamination mode.

[0108] [Note 2] In the rotation mode, the rotating mechanism rotates the rotating body by a predetermined rotation angle each time the stripper separates from the workpiece, as described in [Note 1].

[0109] [Note 3] Each of the two sets of stacking units is located below the rotating body and has a positioning mechanism that 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 lower surface of the rotating body, and the positioning mechanism has a positioning pin inserted into the positioning recess and an actuator that moves the positioning pin forward and backward in the axial direction of the rotating body, as described in [Note 1] or [Note 2].

[0110] [Note 4] The actuator is provided at a position offset radially outward from the positioning pin of the rotating body, and the positioning mechanism has a connecting member that connects the positioning pin and the actuator, as described in [Note 3]. [Explanation of symbols]

[0111] 10… Pressing device 11, 11A, 11B… Stackable Units 30…Rotational body 31... Die 33... Squeeze ring 38…Positioning recess 60... Rotation mechanism 70…Positioning mechanism 71…Positioning 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 pressing method for punching out an iron core piece from a workpiece using two stacking units aligned in the direction of transport of a workpiece that is transported intermittently, Each of the aforementioned stacked units is A lamination mode is formed by punching out the iron core pieces from the workpiece using a die and a punch, and stacking the iron core pieces inside a squeeze ring that communicates with the die, The system is configured to be switchable between a rotation mode in which, with the punch retracted from the workpiece, the stripper that presses the workpiece against the die during punching the iron core piece is separated from the workpiece, and the rotation operation that rotates the die and the squeeze ring is performed multiple times while the stripper moves up and down multiple times. When the upstream stacking unit in the transport direction of the two stacking units 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. Pressing method.

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