JP6294297B2 - Back pressure device for progressive metal mold apparatus, laminated core manufacturing apparatus having the same, and back pressure control method in progressive metal mold apparatus - Google Patents

Description

The present invention relates to a back pressure device for a progressive metal mold apparatus for manufacturing a laminated core formed by laminating a plurality of iron core thin plates, a laminated iron core manufacturing apparatus including the back pressure apparatus, and a back pressure control method in the progressive metal mold apparatus.

  Regarding a laminated iron core for a rotating electrical machine, a method of manufacturing by a progressive die apparatus using a hoop material (strip-shaped thin steel plate) of an electromagnetic steel plate as a raw material is widespread. In the progressive die apparatus, pilot holes, slots, inner diameter teeth, etc. are sequentially punched into the hoop material to continuously form the iron core thin plate, and finally the iron core thin plate whose outer shape is punched A laminated core is manufactured by laminating and fixing a number of sheets.

  When laminating iron core thin plates, each iron core thin plate punched out by punches is sequentially pushed into a squeeze ring provided below the die, and a lateral pressure is applied within the squeeze ring having the same or slightly smaller outer diameter. As a result, the layers are stacked in close contact with each other. As a method of adhering the laminated iron core thin plate, a method of forming caulking unevenness on each iron thin plate and then crimping and bonding at the time of lamination (lamination caulking method), a hoop material in a progressive die apparatus Adhesive is applied to the surface of the steel sheet, and a method of laminating and bonding the core thin plates at the same time as the outer punching (lamination bonding method), a method of laser irradiation to the laminated iron core thin plate (laser welding method), etc. are adopted. ing.

  In order to more effectively stack the core thin plates in the squeeze ring, a cradle is provided on the lower side of the squeeze ring (stacked core discharge side), and this cradle is attached to the lower surface of the lowermost core thin plate. Back pressure devices that apply upward pressure (back pressure) have been developed. In this type of back pressure device, for example, in order to improve the caulking strength by the laminating caulking method, it is conceivable to increase the back pressure against the iron core thin plate, but the increased back pressure is based on the side pressure of the squeeze ring. Exceeding the holding force, the iron core thin plate in the squeeze ring (or die) is pushed up by the cradle (hereinafter referred to as “pushing up the iron core thin plate”), which may cause a trouble.

  Therefore, a back pressure device for avoiding such a trouble of pushing up the iron core thin plate has been developed. For example, the punch includes a mounting table that can be raised and lowered, an elastic member (such as a gas spring) disposed on the mounting table, and a support plate that is provided at the upper end of the elastic member and on which a plurality of iron core thin plates are stacked. At the time of pressing, the height position of the mounting table is fixed, and the elastic member that is compressed by the lowering of the support plate due to the pressing of the punch applies a force in the direction opposite to the pressing direction of the punch to the supporting plate. Thus, a back pressure device is known in which back pressure is more effectively applied (see Patent Document 1).

Japanese Patent No. 4578272

  However, in the conventional technique described in Patent Document 1, it is necessary to provide a mechanism for supporting the support plate with a gas spring or the like on the cradle, so that the structure of the back pressure device becomes complicated and the cost of the device also increases. There is a problem that it is bulky. Furthermore, in the above prior art, it is necessary to provide a guide member or the like (auxiliary mechanism) for guiding the vertical movement of the support plate in order to keep the support plate provided at the upper end of the elastic member substantially horizontal.

The present invention has been devised in view of such problems of the prior art, and with a simple configuration, a progressive feed that generates an appropriate back pressure when punching the core sheet while preventing the core sheet from being pushed up. It is a main object of the present invention to provide a back pressure device for a mold apparatus, a laminated core manufacturing apparatus including the back pressure apparatus, and a back pressure control method in a progressive mold apparatus .

  In the first aspect of the present invention, for a progressive die apparatus for manufacturing a laminated core (3) in which a core sheet (2) is punched from a strip-shaped sheet steel sheet (W) that is intermittently transferred and a plurality of the core sheets are laminated. In the progressive die device (1), the back pressure device (6) is provided in an iron core holding member (22) for holding the iron core thin plate punched out from the strip-shaped thin steel plate, and is movable up and down. A cradle (31) on which thin plates are sequentially placed, a support unit (32) that supports the cradle, a lifting motor (33) that moves the cradle up and down via the support unit, A control device (34) for controlling the rotation operation of the lifting motor, wherein the control device limits a plurality of torque limit values for limiting the output torque of the lifting motor in accordance with the operation of the progressive die device. Set the iron core thin plate During punching, and limits the output torque based on the maximum torque limit value in said plurality of torque limit.

  In the back pressure device for the progressive die apparatus according to the first aspect, the simple structure prevents the core thin plate from being pushed up due to excessive application of back pressure from the cradle, while punching the core thin plate. Appropriate back pressure can be generated. More specifically, at the time of non-punching, each of the core thin plates is increased by increasing the torque limiting value at the time of punching while preventing the iron thin plate from being pushed up by a relatively low torque limiting value (that is, the back pressure that can be applied). The degree of adhesion between the iron cores (that is, the adhering force between the iron core thin plates) can be further increased, and as a result, the space factor of the laminated iron core can be improved.

  According to a second aspect of the present invention, with respect to the first aspect, the control device always limits an output torque of the lifting motor, and the plurality of torque limit values are high torques when the core thin plate is punched. It consists of a limit value and a low torque limit value other than when the iron core thin plate is punched.

  In the back pressure device for the progressive die device according to the second aspect, the simple control of the lifting motor using two torque limit values, ie, the high torque limit value and the low torque limit value, makes it possible to perform non- Appropriate back pressure can be applied at the time of punching.

  According to a third aspect of the present invention, with respect to the first or second aspect, the control device performs positioning control of the elevating motor at least when the iron core thin plate is punched.

  In the back pressure device for the progressive die device according to the third aspect, when punching the core thin plate, the positioning control is performed while limiting the output torque of the lifting motor based on the torque limit value. Appropriate back pressure can be accurately generated at the time of punching, and by appropriately positioning the cradle, the iron core thin plate can be prevented from being pushed up regardless of the torque limit value.

  According to a fourth aspect of the present invention, with respect to any one of the first to third aspects, the support unit includes a ball screw (42) for moving the cradle up and down by being rotationally driven by a lifting motor. The ball screw is reversely operated by a downward pressing force acting on the cradle when the iron core thin plate is punched.

  In the back pressure device for a progressive die apparatus according to the fourth aspect, a ball screw is provided on the support unit that supports the cradle so that the ball screw can be reversely operated (that is, linear (axial direction) motion is converted into rotational motion). The load on the support unit or the like can be reduced (the punching load can be buffered) by reverse operation of the ball screw caused by the lowering of the cradle at the time of punching while applying an appropriate back pressure when punching the iron core.

  In a fifth aspect of the present invention, according to any one of the first to fourth aspects, the control device controls the lifting motor to raise or lower the cradle when the iron core thin plate is punched. It is characterized by controlling.

  In the back pressure device for a progressive die apparatus according to the fifth aspect, the core sheet is punched by raising or lowering the cradle according to the punching condition of the core sheet (the magnitude of the side pressure of the core holding member, etc.). It becomes possible to generate an appropriate back pressure as occasion demands.

  In a sixth aspect of the present invention, according to any one of the fifth aspects, the control device performs positioning control of the elevating motor so as to move the cradle to a target position when the iron core thin plate is punched. It is characterized by doing.

  In the back pressure device for the progressive die apparatus according to the sixth aspect, the cradle is raised or lowered within an appropriate range according to the punching condition of the iron core thin plate, thereby providing a more appropriate back pressure when punching the iron core thin plate. Can be generated.

  A seventh aspect of the present invention is a laminated core manufacturing apparatus including a back pressure device for a progressive mold apparatus according to any one of the first to sixth aspects.

  As described above, according to the present invention, it is possible to generate an appropriate back pressure at the time of punching the iron core thin plate while preventing the iron core thin plate from being pushed up with a simple configuration.

The block diagram which shows the principal part of the progressive die apparatus provided with the back pressure apparatus which concerns on this invention Explanatory drawing which shows the relationship between the position of the punch in a progressive die apparatus, and the rotation angle of a crankshaft Explanatory drawing which shows a series of operation | movement of the back pressure apparatus regarding punching of an iron core thin plate (1st sheet). Explanatory drawing which shows a series of operation | movement of the back pressure apparatus regarding punching of an iron core thin plate (2nd sheet). Explanatory drawing which shows operation | movement of the back pressure apparatus at the time of carrying out a laminated iron core Flow diagram showing the operation flow of the back pressure device FIG. 6 is a flowchart showing the process of step ST105 in FIG. FIG. 6 is a flowchart showing a modification of the process of step ST105 in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a main part of a progressive mold apparatus provided with a back pressure device according to the present invention. The progressive metal mold apparatus 1 is an apparatus that manufactures a laminated iron core 3 formed by laminating a plurality of iron core thin plates 2 by performing metal press processing on a hoop material (strip-shaped thin steel plate) W made of an electromagnetic steel plate. The progressive die apparatus 1 has an upper mold 4 provided so as to be capable of reciprocating in the vertical direction, a lower mold 5 fixed to a holder (not shown), and an upper surface with respect to the lower surface of the iron core thin plate 2 laminated on the lower mold 5. And a back pressure device 6 that applies the pressure (back pressure).

  The upper die 4 includes a plurality of punches for punching the hoop material W (FIG. 1 shows only the punch 10 for outer shape punching), a punch holder 11 for holding these punches, and a punch holder 11. In order to guide the lifting operation, a plurality of guide posts extending up and down (here, only the guide post 12 is shown) and a stripper guide (not shown) are slidably supported, and punch the hoop material W after punching. And a stripper plate 13 to be separated from each other.

  Moreover, the upper part of the upper mold | type 4 is being fixed to the slide part (not shown) which reciprocates (for example, moves up and down with a stroke of about 25 mm-35 mm) to an up-down direction. In the slide portion, the rotational movement of the crankshaft 16 driven by the upper mold drive motor 15 is converted into the vertical movement of the upper mold 4 via a connecting rod (not shown). Further, the slide portion detects the rotation phase of the crankshaft 16 (rotation angle from the reference rotation position of the crankshaft 16), and generates an encoder signal (hereinafter referred to as “synchronization signal”) indicating the detection result. An encoder 17 is provided.

  The lower die 5 is connected to the die 20 provided with a substantially circular outer punching hole into which the substantially cylindrical punch 10 is inserted, the die plate 21 that holds the periphery of the die 20, and the lower end of the die 20, and is laminated. A squeeze ring (iron core holding member) 22 that applies a side pressure (tightening force) to the iron core thin plate 2, a die holder 23 that holds the squeeze ring 22 and supports the lower surface of the die plate 21, and a lower surface of the die holder 23. And a supporting sub-plate 25.

  In the present embodiment, the squeeze ring 22 is used as an iron core holding member for holding the punched iron core thin plate 2. However, at least a plurality of iron core thin plates 2 are accommodated and used for stacking them. Any member having a substantially cylindrical shape can be used as long as the squeeze ring 22 is used. Moreover, as an iron core holding member, not only the thing for the purpose of giving a side pressure with respect to the laminated iron core thin plate 2, but the object for aligning iron core pieces by a cylindrical hole (guide hole) As the hole shape, various shapes such as a square shape, a fan shape, a trapezoidal shape, and a T shape can be adopted in addition to a circular shape, in accordance with the shape of the iron core thin plate 2.

  The inner diameter of the squeeze ring 22 is set to the same size as the inner diameter of the die 20 (set to be the same as the inner diameter or set slightly smaller or slightly larger than the inner diameter). The iron core thin plate 2 punched out in 20 is sequentially moved downward while being held with a predetermined side pressure.

  The back pressure device 6 includes a cradle 31 on which the iron core thin plates 2 punched into the die 20 are sequentially placed, a support unit 32 that supports the cradle 31 from below, and the cradle 31 via the support unit 32. An elevating motor 33 that generates power for elevating, a controller (control device) 34 that controls the rotation operation of the elevating motor 33, and a driver 35 that drives the elevating motor 33 based on a command from the controller 34 Prepare mainly. As the elevating motor 33, a known motor such as a servo motor or a stepping motor can be used.

  The cradle 31 has a flat upper surface 31a that comes into contact with the lower surface of the iron core thin plate 2 in the die 20, the squeeze ring 22, and the like, and presses the iron core thin plate 2 placed on the upper surface 31a upward. A back pressure (pressing force) is applied to the thin plate 2. The cradle 31 can move up and down between an upper limit position set near the upper end of the die 20 and a lower limit position (unloading position) below the squeeze ring 22. The laminated iron core 3 is pushed out to the transfer line by the pusher 36 (see FIG. 5D described later) from the cradle 31 that has moved to the unloading position below the lower mold 5, and is assembled by the conveyor device of the transfer line. It is conveyed to.

  In the present embodiment, a laminated caulking method is used as a method for fixing the iron core thin plates 2, and the laminated iron core 3 is formed by caulking and joining caulking unevenness formed in the iron core thin plates 2 adjacent to each other in the vertical direction. . However, the progressive die apparatus 1 of the present invention is not limited to the laminating caulking method, and other known methods such as a laminating adhesion method using an adhesive as a method for fixing each iron core thin plate 2 and a laser welding method using a laser. The method can also be applied.

  The support unit 32 is provided with a support shaft 41 extending in the vertical direction, and a pair of nuts 43 and a screw shaft 44 constituting a ball screw 42. The support shaft 41 is made of a highly rigid shaft, and movement in the horizontal direction is restricted by a guide (not shown). The upper end portion of the support shaft 41 is connected to the lower portion of the cradle 31, while the lower end portion is fixed to the nut 43. Although not shown here, the nut 43 has a nut-side thread groove that accommodates a ball (rigid ball) in a rollable manner together with a thread shaft-side thread groove provided on the screw shaft 44, as in the known nut, A circulation path and a deflector for circulating the ball are provided. The screw shaft 44 is directly connected to the rotating shaft of the elevating motor 33 so that the shaft center is the motor rotating shaft.

  With such a configuration, in the support unit 32, when the screw shaft 44 rotates in the forward direction due to the forward rotation of the lifting motor 33, the nut 43 rises, thereby the support shaft 41 (and the receiving shaft fixed to the nut 43). The stand 31) also rises. On the other hand, when the screw shaft 44 rotates in the reverse direction due to the reverse rotation of the elevating motor 33, the nut 43 is lowered, and thereby the support shaft 41 fixed to the nut 43 is also lowered.

  In the present embodiment, the screw shaft 44 is rotated by the elevating motor 33. However, the present invention is not limited to this, and the nut may be rotated by the rotation of the elevating motor 33. In this case, the cradle is attached to the screw shaft, and the screw shaft is moved back and forth in the vertical direction by rotation of the nut (that is, the cradle is raised or lowered).

  The elevating motor 33 is provided with an encoder 51 as a speed / position detecting device for detecting the speed and rotation angle (position). The encoder 51 sends the detection result of the speed and the rotation angle to the driver 35 as an encoder signal (hereinafter referred to as “speed / position detection signal”). The speed / position detection device of the lifting motor 33 is not limited to an encoder, and other detection devices such as a resolver may be used. It is also possible to detect the position of the nut 43 using a speed / position detection device such as a linear scale and send the detection result to the driver 35 as a speed / position detection signal.

  The controller 34 acquires a synchronization signal including information on the rotational phase of the crankshaft 16 (that is, the timing of the lifting / lowering operation of the punch 10) from the encoder 17 on the upper mold 4 side, and moves up and down with respect to the driver 35 based on this synchronization signal. By sending the speed command and the position command of the motor 33 for the motor, the rotation operation of the motor (that is, the elevation operation of the cradle 31) is controlled. Based on at least one of the speed command and the position command from the controller 34 and the speed / position detection signal (that is, the speed and position feedback) from the encoder 51, the driver 35 is driven by a lifting motor 33 from a power source (not shown). The rotational speed and stop position of the lifting / lowering motor 33 (that is, the lifting / lowering speed and stop position of the cradle 31) are controlled by controlling the current applied to.

  Further, the controller 34 sends a torque limit command (that is, torque limit value) to the driver 35 based on one or more preset torque limit values. The torque limit value is set based on the pressure (side pressure) applied from the squeeze ring 22 to the peripheral surface of the iron core thin plate 2, the plate thickness of the iron core thin plate 2, and the like from the viewpoint of preventing at least the iron core thin plate 2 from being pushed up. be able to. Based on the torque limit command from the controller 34, the driver 35 sets a current limit value applied to the lifting motor 33 and limits the output torque of the lifting motor 33 (that is, the back pressure of the back pressure device 6). . The torque limit value of the elevating motor 33 is preferably set so that the force for raising the cradle 31 by the elevating motor 33 is smaller than the pressing force by the punch 10.

  In the progressive die apparatus 1 having the above configuration, the first core thin plate 2 punched by the punch 10 is placed on the cradle 31. The second and subsequent iron core sheets 2 are sequentially stacked on the core sheet group punched out and stacked in the die 20 and sequentially pushed into the squeeze ring 22 below the die 20. They are fixed to each other in a prescribed number of core thin plate groups (that is, laminated core 3). At the time of punching with the punch 10, a downward pressing force is generated by the punch 10 on the cradle 31 on which the iron core thin plate 2 is placed. However, since the ball screw 42 is provided in such a manner that it can be operated in reverse, the torque limit value is set. When an excessive load is applied, the motor 33 rotates in the reverse direction. The reverse operation of the ball screw 42 (that is, the lowering of the cradle 31) increases the back pressure and provides a shock absorbing effect by the punch as in the case of the gas spring in the prior art, thereby reducing the load on the support unit 32 and the like. It can be reduced (the punching load is buffered). The configuration of the back pressure device 6 is not limited to the configuration shown here as long as at least the ball screw is provided in a manner that allows reverse operation, and other configurations may be used.

  Although description is omitted in the present specification, in the progressive die apparatus 1, as in the conventional apparatus, the pilot hole or the like is used as a pre-process of the outer punching and laminating (adhering) processes of the iron core thin plate 2 related to the above-described configuration. Each process such as punching of the slot portion and the inner diameter teeth is sequentially performed, and the iron core thin plate 2 is continuously formed. As for the strip layout (the shape of the iron core thin plate 2 and the like) related to the progressive die apparatus 1, any form is applied as long as the back pressure can be applied by the back pressure device 6 when the outer shape of the iron core thin plate 2 is punched out. be able to.

  FIG. 2 is an explanatory view showing the relationship between the position of the punch and the rotation angle of the crankshaft in the progressive die apparatus, and FIGS. 3A to 3C are the first iron core thin plate in the progressive mold apparatus. It is explanatory drawing which shows a series of operation | movement of the back pressure apparatus regarding punching out.

  In FIG. 2, the vertical axis is the position of the tip 10 a of the punch 10 that moves up and down according to the height position of the crankpin 16 a of the crankshaft 16, and the horizontal axis is the rotation angle of the crankshaft 16. Moreover, T1-T5 shown in FIG. 2 has shown the time (namely, elapsed time) in each point. As shown in the figure, the punch 10 is moved up and down again at a time T0 (crankshaft rotation angle 0 °) and again through a bottom dead center at time T3 (crankshaft rotation angle 180 °). Return to top dead center at time T5. The time T2 corresponds to the time when the tip 10a of the punch 10 is lowered to the position of the surface of the hoop material W, and the time T4 is the time when the tip 10a of the punch 10 is again from the bottom dead center to the position of the surface of the hoop material W. Corresponds to the rise time.

  The punching operation of the hoop material W by the punch 10 is performed at times T2 to T4 from when the punch 10 comes into contact with the hoop material W to return to the original position. However, the punching of the iron core thin plate 2 into the die 20 is generally completed at times T2 to T3 from when the punch 10 contacts the hoop material W until the bottom dead center is exceeded.

  In the present embodiment, as the synchronization signal from the encoder 17, the synchronization signal 1 sequentially transmitted from the encoder 17 at the timing immediately after the start of punching of the iron core thin plate 2 (time T0 or T5 in FIG. 2), and at least A synchronization signal 2 that is sequentially sent from the encoder 17 at a timing before a predetermined time Tz from a scheduled time (see time T3 in FIG. 2) when the punch 10 reaches bottom dead center is used.

  3A shows a state before the start of the lifting / lowering operation of the punch 10, and the tip 10a of the punch 10 is at the upper limit position (corresponding to the top dead center at time T0 in FIG. 2). The cradle 31 is in an initial position (here, the upper limit position of the cradle 31) lowered by a predetermined length with respect to the upper end surface 20a of the die 20. After the cradle 31 is temporarily stopped at this initial position, the cradle 31 is lowered to a punching position for corresponding to the punching operation of the first core thin plate 2.

  3B shows a state in which the punch 10 starts to descend from the upper limit position of FIG. 3A toward the hoop material W, and the tip 10a of the punch 10 has an upper limit position and a lower limit position (FIG. 2). (Corresponding to the middle point at time T1 in FIG. 2). Further, the upper surface 31a of the cradle 31 is at the same position as that in FIG.

  FIG. 3C shows a state in the middle of the punching operation of the first thin iron core plate 2 by the punch 10, and the tip 10a of the punch 10 corresponds to the lower limit position (the bottom dead center at time T3 in FIG. 2). )It is in. Further, the cradle 31 is lowered from the position of FIG. 3B when the ball screw 42 is reversely operated by the pressing of the punch 10. At this time, the upper surface 31a of the cradle 31 is based on the upper end surface 20a of the die 20 and the insertion depth (engagement length) L (see FIG. 3C) of the punch 10 with respect to the die 20 at the lower limit position and the iron core thin plate. It moves to a lower position (punching position) by a length (L + t) obtained by adding the thickness t of 2.

  FIG. 4 is an explanatory view showing the operation of the back pressure device related to the punching of the second core thin plate in the progressive die apparatus.

  FIG. 4A shows a state in which the punch 10 has returned to the upper limit position (corresponding to the top dead center at time T5 in FIG. 2) after the punching operation of the first sheet of iron core 2. On the other hand, the upper surface 31a of the cradle 31 is at a position below the upper end surface 20a of the die 20 by L + t, as in FIG.

  4B shows a state in which the punch 10 starts to descend again from the upper limit position of FIG. 4A toward the hoop material W, and the tip 10a of the punch 10 is the same as in FIG. 3B. And between the upper limit position and the lower limit position. Further, the upper surface 31a of the cradle 31 is at the same position as that in FIG.

  FIG. 4C shows a state in the middle of the punching operation of the second core thin plate 2 by the punch 10, and the tip 10a of the punch 10 is at the lower limit position as in the case of FIG. 3C. Further, the upper surface 31a of the cradle 31 is lowered from the position shown in FIG. 4B when the ball screw 42 is reversely operated by the pressing of the punch 10. At this time, the upper surface 31a of the cradle 31 is obtained by adding the insertion depth L of the punch 10 (see FIG. 4C) and the thickness 2t of the two core thin plates 2 with respect to the upper end surface 20a of the die 20. It moves to the lower punching position by the length (L + 2t). The same operation as described above is repeated for punching the third and subsequent core thin plates 2.

  FIGS. 5A to 5E are explanatory views showing the operation of the back pressure device when the laminated iron core is carried out. Here, FIG. 5A shows a state similar to FIG. Thereafter, as described above, in the progressive die apparatus 1, the core thin plate 2 is sequentially punched into the die 20 by repeatedly performing the operations (external punching and laminating process) shown in FIGS. 3 and 4. Laminated. Further, each punched iron core thin plate 2 is sequentially pushed into the squeeze ring 22 from the die 20 as shown in FIG. 5B while being given a lateral pressure by the squeeze ring 22 and a back pressure by the back pressure device 6. In the squeeze ring 22, it is firmly fixed (here, caulked and joined).

  FIG. 5C shows a state in which a core thin plate group in which a predetermined number of core thin plates 2 are fixed to each other is discharged as one laminated iron core 3 from the lower end of the squeeze ring 22. At this time, the cradle 31 on which the laminated iron core 3 is placed is in a state of being lowered to a conveyance position (here, a lower limit position) below the lower mold 5.

  FIG. 5D shows a state in which the laminated core 3 on the cradle 31 at the transfer position is being pushed out to the transfer line (not shown) by the pusher 36. When the laminated iron core 3 is pushed out to the transfer line (that is, removed from the upper surface 31a), the cradle 31 rises again and returns to the initial position. At this time, as shown in FIG. 5E, the upper surface 31a of the cradle 31 comes into contact with the lower surface of the lowermost core thin plate 2 in the lowermost laminated core 3 held in the squeeze ring 22. As a result, the back pressure is again applied to the iron core thin plate group in the squeeze ring 22.

  FIG. 6 is a flowchart showing the operation flow of the back pressure device. When the back pressure device 6 is activated, the controller 34 performs the following steps ST101 to ST104 as an initial operation before starting punching in the progressive die apparatus 1.

  With respect to the initial operation, first, the controller 34 sends a torque limit command for setting the torque limit value to “low” to the driver 35, and the driver 35 sends to the lifting motor 33 based on the torque limit command. An applied current limit value is set (ST101).

  In the present embodiment, the torque limit value is set in two stages of “high” and “low”, and the torque limit of “high” or “low” is always set. The torque limit value “low” is set to a value that does not cause the core thin plate 2 to be pushed up. More preferably, the core thin plate 2 is not pushed up, and the warp of the iron core thin plate 2 caused by the side pressure of the squeeze ring 22 is more preferable. It is set to a value that can suppress the occurrence. The torque limit value “low” only needs to be set to a size that allows at least the cradle 31 to be moved up and down. On the other hand, the torque limit value “high” is a value that is at least higher than the torque limit value “low”. With the torque limit value “high” in the present embodiment, the iron core thin plate 2 may be pushed up when the punch 10 is not subjected to a downward pressure in the punching operation (that is, when not punched). However, the present invention is not limited to this, and the torque limit value “high” may be set to a size that does not push up the iron core thin plate 2 when not punched.

  Thereafter, the controller 34 starts speed control by sending a speed command of the lifting motor 33 to the driver 35 (ST102), whereby the cradle 31 is raised to the initial position at a predetermined speed (ST102). ST103). At this time, when the iron core thin plate 2 does not exist in the die 20 or the squeeze ring 22, the preset upper limit position (see FIG. 3A) is the initial position of the cradle 31. On the other hand, when the punched iron core sheet 2 is present in the die 20 or the squeeze ring 22, the controller 34 detects the contact (collision) of the cradle 31 against the lower surface of the core sheet 2, and The position where contact is detected (see FIG. 5E) is the initial position of the cradle 31. The contact of the cradle 31 with the lower surface of the iron core thin plate 2 can be detected by the load current of the lifting motor 33. On the other hand, for example, a force sensor 55 (see FIG. 1) may be provided on the upper portion of the cradle 31, and the contact of the cradle 31 may be detected by the force sensor 55. In addition, by using another known sensor such as a proximity sensor instead of the force sensor 55, the contact of the cradle 31 with the lower surface of the iron core thin plate 2 may be detected. In addition, as a preferable example, the control in step ST102 is speed control and the control in step ST104 is positioning control. However, each control can be performed by any of speed control, positioning control, and torque control.

  Thereafter, the controller 34 switches from speed control to positioning control (ST104), and subsequently performs a back pressure applying operation at the time of punching the outer shape (ST105). The operation relating to step ST105 will be described in detail later. In step ST105, the torque limit value is set to “high”. When the back pressure application operation in step ST105 is completed (that is, the laminated core 3 is discharged from the squeeze ring 22 and needs to be carried out), the controller 34 then stacks the laminated core in the progressive die apparatus 1. As the unloading operation 3, the following steps ST106 to ST110 are performed.

  Regarding the carry-out operation, first, the controller 34 sends the positioning command to the driver 35 to lower the cradle 31 to the carry-out position (ST106). Thereafter, the controller 34 sends a torque limit command for setting the torque limit value to “low” to the driver 35 (ST107), and further sends the speed command to the driver 35, thereby again controlling the speed. Is started (ST108). Thereby, the cradle 31 is raised to the initial position at a predetermined speed (ST109). At this time, the controller 34 detects the contact (collision) of the cradle 31 with the lower surface of the iron core thin plate 2 that has already been punched, and sets the contact position as the initial position.

  Thereafter, the controller 34 switches from speed control to positioning control (ST110). Here, when the punching of all the iron core thin plates 2 has not been completed (ST111: No), the process returns to step ST105 and the above steps are repeated. Finally, when the punching of all the iron core thin plates 2 is finished (ST111: Yes), a series of operations of the back pressure device 6 is also finished. As a preferred example, the control of ST108 is speed control and the control of ST110 is positioning control. However, each control can be performed by any of speed control, positioning control, and torque control.

  FIG. 7 is a flowchart showing the process of step ST105 in FIG. When punching of the iron core thin plate 2 is started in the progressive die apparatus 1, the controller 34 waits to receive the synchronization signal 2 from the encoder 17 on the upper mold 4 side (ST201).

  Thereafter, when the controller 34 receives the synchronization signal 2 (ST201: Yes), the controller 34 sends a torque limit command for setting the torque limit value to “high” to the driver 35, and the driver 35 Based on the torque limit command, a current limit value applied to the lifting motor 33 is set (ST202). Subsequently, when the controller 34 determines that a preset time (time until the punch 10 reaches the bottom dead center) Ty has elapsed since the reception of the synchronization signal 1 (ST203: Yes), the cradle at that time point The position 31 is determined (stored) as the position when the bottom dead center of the punch 10 is reached (hereinafter referred to as “position A”) (ST204).

  Thereafter, the controller 34 sends a torque limit command for setting the torque limit value to “low” to the driver 35 (ST205), and then sends a positioning command for the lifting motor 33 to the driver 35. As a result, if there is a deviation from the position A, the cradle 31 moves to the position A (ST206). The operations in steps ST201 to ST206 are repeatedly executed until the time at which each laminated iron core 3 is ejected from the squeeze ring 22 comes (ST207: Yes). The controller 34 determines the discharge timing of the laminated core 3 in step ST207 based on whether or not the cradle 31 has reached a preset unloadable position.

  FIG. 8 is a flowchart showing a modification of the process of step ST105 in FIG. When punching of the iron core thin plate 2 is started in the progressive die apparatus 1, the controller 34 waits to receive the synchronization signal 2 from the encoder 17 on the upper mold 4 side (ST301).

  Thereafter, when the controller 34 receives the synchronization signal 2 (ST301: Yes), the controller 34 sends a torque limit command for setting the torque limit value to “high” to the driver 35 (ST302). Subsequently, the controller 34 sends a positioning command for moving the cradle 31 to a preset position B (target position) to the driver 35 (ST303).

  Thereafter, the cradle 31 moves to a preset position B based on the positioning command in step ST302 (ST304). The time Tz may be set so that the cradle 31 is in the process of moving to the position B when the punch 10 reaches the bottom dead center. That is, in FIG. 7, the punch 10 reaches the bottom dead center with the cradle 31 stopped. However, in the modified example of FIG. 8, the punch 10 is lowered with the cradle 31 raised or lowered. Reach the dead center. Thereby, the back pressure device 6 can generate an appropriate back pressure when the iron core thin plate 2 is punched. The raising or lowering of the cradle 31 can be selected based on the lateral pressure of the squeeze ring 22, the thickness of the iron core thin plate 2, or the like. Note that the movement of the cradle 31 in step ST303 is preferably performed by positioning control. However, the present invention is not limited to this, and a plurality of control modes can be set. It is also possible to use a combination of forward or reverse) command and speed control or torque control.

  Subsequent steps ST305 to ST309 are the same as steps ST203 to ST207 in FIG.

  As described above, in the back pressure device 6 of the progressive die apparatus 1, the controller 34 sets two torque limit values (“high” and “low”), and the torque limit value “ Since “high” is set to a value larger than the torque limit value “low” when not punched, the iron sheet 2 is prevented from being pushed up by a relatively low torque limit value “low” when not punched. By setting a relatively high torque limit value “high” at the time of punching, the degree of adhesion between the iron cores (that is, the adhering force between the iron core thin plates 2) is increased, and as a result, the space factor of the laminated iron core 3 is increased. Can be improved.

  Note that the torque limit value is not limited to that shown here, and the progressive money is applied as long as the maximum torque limit value is applied when the core sheet is punched (at least including the time T3 shown in FIG. 2). More torque limit values may be set according to the operation of the mold apparatus 1. However, when two torque limit values (“high” and “low”) are used, the control of the lifting motor 33 is easy.

  As mentioned above, although this invention was demonstrated based on specific embodiment, these embodiment is an illustration to the last, Comprising: This invention is not limited by these embodiment. It should be noted that the back pressure device for the progressive mold apparatus according to the present invention and the constituent elements of the progressive mold apparatus having the same according to the present invention are not necessarily essential, and at least depart from the scope of the present invention. As long as it is not, selection can be made as appropriate.

DESCRIPTION OF SYMBOLS 1 Progressive die apparatus 2 Iron core thin plate 3 Laminated core 4 Upper mold 5 Lower mold 6 Back pressure apparatus 10 Punch 16 Crankshaft 20 Die 20a Die upper end surface 22 Squeeze ring (iron core holding member)
31 cradle 31a cradle upper surface 32 support unit 33 lift motor 34 controller (control device)
35 Driver 41 Support shaft 42 Ball screw 43 Nut 44 Screw shaft 51 Encoder 55 Force sensor W Hoop material (strip-shaped thin steel plate)

Claims (8)

A back pressure device for a progressive die device that punches an iron core thin plate from a strip-shaped thin steel plate that is intermittently transferred and produces a laminated iron core obtained by laminating a plurality of the iron core thin plates,
In the progressive die apparatus, a cradle provided so as to freely move up and down, on which the iron core thin plates are sequentially placed,
A support unit for supporting the cradle;
A lifting motor that moves the cradle up and down via the support unit;
A control device for controlling the rotation operation of the lifting motor,
The control device, based on at least one torque limit value, prevents the thrust of the core thin plate while applying a back pressure to the core thin plate by the cradle when the core thin plate is punched. A back pressure device for a progressive mold apparatus characterized by limiting the output torque of the mold.   2. The control device according to claim 1, wherein the control device sets a plurality of the torque limit values, and sets the torque limit value when the iron core thin plate is punched to a value larger than the torque limit value when the core sheet is not punched. Back pressure device for progressive mold equipment.   3. The back pressure device for a progressive die device according to claim 1, wherein the control device performs positioning control of the elevating motor at least when the iron core thin plate is punched. 4. The support unit includes a ball screw that moves up and down the cradle by being rotationally driven by a lifting motor;
4. The back for a progressive die apparatus according to claim 1, wherein the ball screw is reversely operated by a downward pressing force acting on the cradle when the iron core thin plate is punched. 5. Pressure device.   The said control apparatus controls the said raising / lowering motor so that the said cradle may be raised or lowered at the time of the punching of the said iron core thin plate, The progressive money in any one of Claim 1 to 4 characterized by the above-mentioned. Back pressure device for mold device.   The said control apparatus controls positioning of the said raising / lowering motor so that the said cradle may be moved to a target position at the time of the punching of the said iron core thin plate, The spine for progressive die apparatuses of Claim 5 characterized by the above-mentioned. Pressure device.   A laminated core manufacturing apparatus comprising the back pressure device for the progressive die apparatus according to any one of claims 1 to 6. It is a back pressure control method in a progressive mold apparatus for punching an iron core thin plate from a strip-shaped thin steel plate that is intermittently transferred and manufacturing a laminated iron core obtained by laminating a plurality of the iron core thin plates,
The progressive metal mold apparatus is provided with a back plate on which the iron core thin plate is sequentially placed and a back pressure device including a lifting motor for moving up and down the receiving plate,
At the time of punching the iron core thin plate, the output torque of the lifting motor is limited based on at least one torque limit value in order to prevent the iron core thin plate from being pushed up while applying back pressure to the iron core thin plate by the cradle. A back pressure control method in a progressive mold apparatus characterized by:

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