Method and device for controlling a ram drive, method for determining a modified drive curve, and computer program product

Abstract

The invention relates to a method (V) and a device (10) for controlling a ram drive (17) of a cyclically operating forming and / or punching machine (11). For the course of each working cycle (C), working points of a ram (16) are defined by at least one working parameter set (Wi), and from these a drive curve (A) for the ram (16) is then determined. On the basis of this drive curve (A), it is checked whether a predefined admissible maximum load (Lmax) is adhered to. If not, then at least one modified drive curve (Amod) is determined using a filter, for example an FIR filter, which is applied to the drive curve (A) or to a control curve (S) correlating therewith. If a plurality of modified drive curves (Amod) are determined, it is possible to select from these the modified drive curve (Amod) which allows operation that is best suited to the application, for example allows the highest productivity or stroke rate of the forming and / or punching machine (11).

Description

Method and device for controlling a plunger drive, method for determining a modified drive curve, and computer program product

[0001] The invention relates to a method and a device for controlling a ram drive. The ram drive is configured to move a ram of a forming and / or stamping machine in a working direction. For this purpose, the ram is mounted on a machine frame so as to be movable in the working direction. The invention also relates to a method for determining at least one modified drive curve, and to a computer program product with program code which, when executed, causes a control device to execute one of the methods.

[0002] The forming and / or stamping machine is designed as a cyclically operating machine. The processing of one or more workpieces takes place during each work cycle and is repeated in successive work cycles. For example, in each work cycle, a workpiece can be fed into the forming and / or stamping machine, processed by the machine, and then removed from the machine. The forming and / or stamping machine can be, for example, a press for drawing, deep drawing, hot forming, cold forming, cutting and / or stamping, forging, etc., or any combination thereof.

[0003] With such forming and / or stamping machines, the workflow during a work cycle must be adapted to the tool used, the type of workpiece being processed, the The machining operation to be performed, the transfer movement, and the transfer time for feeding and removing the workpiece into and out of the machine must be adjusted. The ram position and / or the ram movement (e.g., speed and / or acceleration and / or change in acceleration) must be set based on the above considerations. Excessive wear on a tool, the forming and / or stamping machine, and the workpiece being machined must be avoided. Furthermore, the ram must allow sufficient freedom of movement for feeding and removing a workpiece into and out of a tool or the forming and / or stamping machine.

[0004] In addition, other boundary conditions must also be taken into account, such as noise generated during the operation of the forming and / or stamping machine, as well as vibrations and forces introduced into the subsoil (foundation) on which the press is placed.

[0005] DE 10 2018 102 809 Al describes a press and a method for its operation in which an operator is given the possibility to vary the setting of the press depending on the forming result by means of several individually adjustable functions in a matrix in order to achieve a desired result.

[0006] From WO 2019 / 051619 Al, the use of spring-damper elements to support a press is known in order to reduce the load on the substrate. Furthermore, it is intended to prevent the press from "rocking".

[0007] To prevent damage, DE 10 2018 113 880 Al proposes that when operating a press The system aims to acquire measured values, particularly force-displacement measurements, in real time using sensors and evaluate them with the aid of machine models and specialized algorithms, specifically to determine the pressing force, tilting moment, and tilting angle of the press ram. This will allow for the determination of current press loads and their comparison with model-based limit loads. The goal is to prevent overloads caused by excessive pressing or forming forces by providing real-time comparison results and displaying them to an operator.

[0008] In JP 2008-290 126 A, a press is described in which press frame vibrations are to be at least reduced by means of a damping control system. For this purpose, the damping control system receives the position and velocity of the press frame moving due to the vibrations, from which it calculates a ram movement to minimize the resulting vibrations. This can impair productivity, for example, if the ram velocity is reduced to dampen the vibrations.

[0009] In the servo press disclosed in DE 10 2007 003 335 A, the servo motors are monitored for overload. If an overload occurs, the stroke rate (complete stroke movements of the press ram or cycles per unit of time) of the servo press is reduced to prevent overloading the servo motors. However, this reduction in stroke rate leads to an undesirable decrease in the productivity of the servo press.

[0010] Starting from the prior art, the object of the present invention is to create a method and a device for controlling a plunger drive, where, on the one hand, necessary boundary conditions are met and, on the other hand, high productivity is ensured.

[0011] This problem is solved by a method with the features of claim 1, a method for determining at least one usable modified drive curve with the features of claim 11, a computer program product with the features of claim 12, and a device with the features of claim 13.

[0012] The method and / or device according to the invention serve to control a ram drive of a cyclically operating forming and / or punching machine. The ram drive is configured to move a ram in a working direction. The working direction can, for example, be vertical. The ram is mounted to a machine frame, either directly or indirectly, so that it can move in the working direction, for example, by means of a suitable guide. In particular, the ram is configured to carry a tool component for machining a workpiece. The tool component arranged on the ram can cooperate with another tool component to machine the workpiece. The other tool component can, for example, be fixedly mounted directly or indirectly on the machine frame.

[0013] The forming and / or punching machine can perform a defined machining task on one or more workpieces in each work cycle, for example, forming and / or cutting and / or punching a workpiece, etc. The forming and / or punching machine can, for example, be a press. A punching machine can be configured, for example, to process a workpiece by hot forming, cold forming, deep drawing, extrusion, forging, cutting, punching, etc., or any combination of the aforementioned processes. In particular, the same processing operation can be performed on at least one workpiece in each work cycle. It is desirable to achieve the highest possible productivity and, for example, to keep the cycle time of a work cycle as short as possible.

[0014] First, at least one set of work parameters is specified. Each work parameter set defines a ram position in the working direction and / or a ram movement in the working direction at a specified time during a work cycle of the forming and / or punching machine. For example, at several times during a work cycle, a ram position and, optionally, a ram movement associated with this ram position (e.g., ram speed and / or ram acceleration) can be specified. These specifications by the at least one work parameter set serve to adapt the workflow during a work cycle to the workpiece being processed, the tool used, and the required transfer movement (feeding and / or removing the workpiece). Undesired collisions, excessive loads, and damage must be avoided.

[0015] The work parameter set therefore specifies boundary conditions that must be adhered to by defining a ram position and / or a ram movement in the working direction at at least one point in time within the work cycle. Each work cycle can thus defined by a single complete period or equivalently by a virtual guide angle, where the guide angle changes by 360° during a complete work cycle (i.e., starting at 0° and ending at 360°).

[0016] Subsequently, a drive curve for controlling the ram drive is determined based on at least one set of operating parameters. This drive curve can also be referred to as the original drive curve or output drive curve. The drive curve can, for example, be a time-dependent progression of the ram position during a work cycle. The drive curve is, in particular, continuous and, especially, continuously distinguishable at least once or twice. The drive curve can be determined using suitable known methods, such as those described in VDI Guideline 2143. The drive curve can, for example, be modeled at least section by a Bézier curve and / or a spline.

[0017] Based on the determined original drive curve, at least one load parameter is then determined. For example, the load parameter can describe a vibration at the forming and / or stamping machine or a related component. Additionally or alternatively, the at least one load parameter can describe a force or force application into a surface on which the forming and / or stamping machine is mounted. The at least one load parameter can be determined using a model of the forming and / or stamping machine. The at least one load parameter can be not only a single value, but also A load parameter can be a group or temporal sequence of several values, a continuous or discrete time progression, a curve, a characteristic map, a table, a function, etc. Each load parameter is therefore not a sensor-acquired measurement, but a calculated quantity, determined in particular based on a computational model, a computational algorithm, or another computational method, and dependent on the original drive curve.

[0018] Subsequently, at least one load parameter is checked to ensure that a specified maximum permissible load is adhered to. For each determined load parameter, a condition describing the maximum permissible load can be checked separately. For example, a maximum vibration amplitude and / or a maximum permissible force on the substrate can be specified and checked for compliance.

[0019] If it is determined that the specified maximum load has not been adhered to, at least one modified drive curve is determined. The part of the method for determining the at least one modified drive curve represents an independent inventive aspect from the rest of the described method.

[0020] To determine at least one modified drive curve, the original drive curve and / or a control curve describing the original drive curve are filtered. For example, a finite impulse response (FIR) filter can be used for filtering. A control curve can, for example, define a rotary motion of a motor and / or eccentric of the tappet drive during a work cycle, i.e., for example, a- a time-dependent speed and / or torque curve of a motor of the tappet drive, in particular an electric motor.

[0021] The filtering process uses at least one set of filter parameters. This at least one set of filter parameters can, for example, be predefined. Filtering with each available set of filter parameters results in a modified drive curve based on the original drive curve and / or the control curve.

[0022] The filtering is designed to filter the original drive curve and / or the control curve describing the original drive curve in such a way that the stroke rate of the forming and / or stamping machine is not reduced or the duration of the work cycle is not extended. Rather, the filtering is designed to modify the curve profile of at least one modified drive curve compared to the original drive curve within the work cycle. The curve profile describes the ram position and / or a movement of the ram in the working direction at each point in time within the considered work cycle – analogous to the boundary conditions specified by the at least one set of working parameters. The filtering serves to dampen vibrations, particularly in the region of a natural frequency of the forming and / or stamping machine, by modifying the curve profile (which can also be referred to as the curve shape).In particular, the duration of the duty cycle is not changed during filtering.

[0023] Within the framework of determining at least one modified drive curve, each determined modified The drive curve must be checked to ensure that the specifications of at least one set of operating parameters are met and / or that the permissible maximum load is adhered to. Either the drive curve or one of the determined modified drive curves can then be used for operating the forming and / or stamping machine, which on the one hand fulfills the specifications and boundary conditions and on the other hand enables the highest productivity of the forming and / or stamping machine.

[0024] Thus, it is possible to determine several modified drive curves using different sets of filter parameters and to disregard all modified drive curves that do not comply with the boundary conditions resulting from at least one set of work parameters or that do not comply with the permissible maximum load. From the remaining, eligible modified drive curves, one can then be selected for use.

[0025] A reduction in the stroke rate or an extension of the duty cycle duration is only carried out if neither the original drive curve nor any of the determined modified drive curves meets the permissible maximum load under the boundary conditions of the work parameter set. Alternatively or additionally to extending the duty cycle duration, a change to the work parameter set can also be made, provided this is possible without causing damage or excessive wear.

[0026] The inventive method can be used to achieve a It must be ensured that specifications and boundary conditions are met. Furthermore, a short cycle time of a work cycle and thus a high stroke rate can be achieved. Until now, exceeding maximum loads has generally been addressed by reducing the stroke rate of a machine (extending the cycle time), which, however, negatively impacts productivity. The invention provides a way to maximize productivity while adhering to specifications and boundary conditions.

[0027] It is advantageous if, in determining the at least one modified drive curve, the control curve is filtered using at least one set of filter parameters, and the resulting modified drive curve is then determined based on each filtered control curve. The relationship between the control curve on the one hand and the drive curve on the other is known and can, for example, be defined by the mechanical coupling between a motor of the tappet drive and the tappet.

[0028] Each filter parameter set can be defined, for example, by a transfer function. In particular, each filter parameter set defines a frequency-dependent attenuation effect of the filter. For example, a filter parameter set can have or be described by at least one frequency to be attenuated and a filter order. Each filter parameter set can have a filter characteristic corresponding to a low-pass, high-pass, band-pass, or band-stop filter with a given order.

[0029] As explained, it is preferably checked for each modified drive curve whether the specifications defined by the at least one set of operating parameters are met. If this is not the case, the modified drive curve can either be discarded or subsequently corrected so that the specifications of the at least one set of operating parameters are met.

[0030] It is also advantageous if, for each modified drive curve, or at least each modified drive curve that conforms to the specifications of at least one set of operating parameters, at least one load parameter is determined and checked to ensure that the permissible maximum load is not exceeded. The procedure here is analogous to the load check based on the original drive curve.

[0031] The drive curve or one of the modified drive curves is then selected for the operation of the forming and / or stamping machine, i.e., used to control the ram drive. The drive curve or one of the modified drive curves that allows the highest stroke rate while fulfilling the requirements of at least one set of operating parameters and adhering to the permissible maximum load can be used.

[0032] Any embodiment of the method described above can be implemented in a control unit of a device according to the invention. The control unit can be used to control the ram drive of the forming and / or stamping machine.

[0033] The control unit can only be a local control unit of the forming and / or stamping machine. Alternatively, the control unit can use computing and / or storage capacities available remotely from the installation location of the forming and / or stamping machine. For example, the control unit can have a local control unit on the forming and / or stamping machine that is connected to an external control unit. The external control unit can be, for example, an internet service or cloud service.

[0034] Advantageous embodiments of the invention are described in the dependent claims, the description, and the drawing. Advantageous embodiments of the invention are explained in detail below based on the accompanying drawing. The drawing shows:

[0035] Figure 1 shows a schematic, block diagram-like representation of an exemplary embodiment of a device according to the invention comprising a forming and / or stamping machine.

[0036] Figure 2 shows a schematic representation of a model of the forming and / or stamping machine from Figure 1.

[0037] Figure 3 shows a schematic representation of a set of operating parameters specified for the operation of the device from Figure 1.

[0038] Figure 4 shows a schematic representation of a drive curve determined on the basis of the working parameter sets from Figure 3, as well as a control curve describing the drive curve.

[0039] Figure 5 shows an effect on a substrate Force dependent on a frequency of an oscillation of the forming and / or stamping machine from Figure 1,

[0040] Figure 6 shows a vibration of a spring-damping element of the forming and / or stamping machine from Figure 1.

[0041] Figure 7 Transfer functions of filters for determining modified drive curves for controlling the plunger drive of the device from Figure 1,

[0042] Figure 8 shows a schematic representation of an original drive curve and a modified drive curve for controlling the plunger drive of the device from Figure 1.

[0043] Figure 9 shows a flowchart of an embodiment of a method according to the invention and

[0044] Figure 10 shows a flowchart of an embodiment of part of the method from Figure 9 for determining a modified drive curve.

[0045] Figure 1 shows an embodiment of a device 10 in block diagram form. The device 10 includes a forming and / or punching machine 11. The forming and / or punching machine 11 is configured to operate cyclically and to process at least one workpiece 12 in each work cycle C. The workpiece 12 can be formed and / or separated (cut and / or punched). The forming of a workpiece 12 can be carried out by cold forming or hot forming. Any known forming processes can be used, such as deep drawing, stretch drawing, forging, etc.

[0046] The forming and / or punching machine 11 has a machine frame 13 which is mounted on a base 15 via spring-damper elements 14. The base 15 can be, for example, a foundation or a floor surface in a factory hall. The spring-damper elements 14 are designed to dampen vibrations and / or shocks that may occur during the operation of the forming and / or punching machine 11 in order to reduce the load on the base 15.

[0047] A ram 16 is movably mounted on the machine frame 13 in one working direction. A guide device may be provided between the ram 16 and the machine frame 13 for this purpose. The forming and / or punching machine 11 has a ram drive 17 to move the ram 16. The ram drive 17 has at least one controllable motor, in particular an electric motor 18. The at least one electric motor 18 is coupled to the ram 16 via a coupling device 19 to transmit a movement of the at least one electric motor 18 to the ram 16 and / or to transmit a torque generated by the at least one electric motor 18 to the ram 16, for example, to generate a desired force that the ram 16 must or should exert for machining the workpiece 12.

[0048] The device 10 has a control unit 20 for controlling the ram drive 17. In one embodiment, the control unit 20 can include a local control unit 21, which is located at the installation site of the forming and / or stamping machine 11 and may, for example, have an operator interface. In another embodiment, the control unit 20 can be implemented exclusively by the local control unit 21. Alternatively, it is also possible to provide an external control unit 22 in addition to the local control unit 21, which is communicatively connected to the local control unit 21. The external control unit 22 can, for example, be an internet service or cloud service. The external control unit can provide storage capacity, computing capacity, or additional data or information that may be available from other machines, for example.

[0049] For machining the at least one workpiece 12, a tool part 25 can be arranged on the ram 16. The tool part 25 arranged on the ram can cooperate with another tool part 26, arranged directly or indirectly on the machine frame 13, for machining the at least one workpiece 12. The two tool parts 25, 26 form a tool of the forming and / or stamping machine 11. The type and design of the tool parts 25, 26 are adapted to the machining task.

[0050] The forming and / or stamping machine 11, schematically depicted in Figure 1, can be modeled by a model 30 shown in Figure 2 in order to determine at least one load parameter L. The at least one load parameter L can, for example, be a force F acting on the base 15 and / or a vibration x, for example, a vibration x perpendicular to the base 15 and, for example, parallel to the working direction R. The vibration x can, for example, describe a time-dependent displacement or amplitude of one, several, or all spring-damper elements 14.

[0051] Model 30 includes a mass m, which is the one that- The spring-damped mass of the forming and / or stamping machine 11 is characterized by the spring-damper elements 14. This mass is coupled to the base 15 in a spring-damped and damped manner, which is described by a spring constant K or spring characteristic and a damping constant d. The spring constant K and the damping constant d are defined in particular by the spring-damper elements 14, whereby other elastically deformable or vibration-prone components of the forming and / or stamping machine 11 can optionally also be taken into account, for example the machine frame 13 or parts thereof.

[0052] Boundary conditions are specified for the operation of a forming and / or stamping machine 11. In particular, a maximum load L is to be specified. maxmust not be exceeded. This can be verified using at least one load parameter L, which can be determined based on model 30. For example, a vibration x resulting from an excitation E of mass m, as shown in model 30, can be determined, and the amplitude of the vibration x can be compared with a permissible maximum amplitude B, as schematically illustrated in Figure 6. A time history of a force F acting on the substrate 15, when mass m is excited with excitation E, can also be determined using model 30. The resulting force F can then be compared with a permissible maximum force F. max They can be compared as shown schematically in Figure 5.

[0053] In general, any determined load parameter L can be selected in the time domain and / or the frequency domain. For example, the evaluation of the vibration x can be performed in the time domain (Figure 6) and the evaluation of the force F can be performed in the frequency domain (Figure 5). For evaluation in the frequency domain, the relevant load parameter L can be transformed from the time domain to the frequency domain using a suitable transformation, for example based on a Fourier transformation, in particular a fast Fourier transformation (FFT).

[0054] Each determined load parameter L can be assigned a separate condition, for example, a separate limit value. For instance, the vibration x is assigned a maximum permissible amplitude B. The maximum load L maxThe limit is maintained for the oscillation x if the oscillation x at any time during a work cycle C with cycle duration T has an amplitude that corresponds at most to the maximum permissible amount B of the amplitude, as shown schematically in Figure 6.

[0055] A force F acting on the substrate 15 as a load parameter L can be subjected to a maximum permissible force F max They can be compared (in the time domain and / or in the frequency domain). In the exemplary embodiment shown in Figure 5, the maximum permissible force F max dependent on a frequency f. The maximum permissible force F max Therefore, it does not have to be constant, but can in turn vary depending on the parameters. In a variation of the representation in Figure 5, the maximum permissible force F could be max A constant maximum value can also be specified for all frequencies f. The maximum permissible force F maXfThe permissible action on the substrate 15 depends on the specific conditions at the installation site of the forming and / or punching machine 11, for example on the construction of the substrate 15, the maximum permissible vibrations transmitted from the substrate 15 to the environment, etc.

[0056] In addition to such a specified maximum load L maxIn addition to the at least one load parameter L, further boundary conditions must be observed during the machining of the at least one workpiece 12. These conditions may depend in particular on the workpiece type 12, the tool 25, 26 used, the specific machining task (forming and / or punching and / or cutting, etc.), the method of workpiece transfer (feeding the at least one workpiece 12 into the forming and / or punching machine 11 and removing the at least one workpiece 12 from the forming and / or punching machine 11), etc. Based on such boundary conditions, at least one set of operating parameters Wi can be specified and transmitted to the control unit 20. For example, the at least one set of operating parameters Wi (i = 1, 2, 3, ... n) can be specified by an operator via an operator interface or transmitted to the control unit 20 in another way.

[0057] The at least one set of work parameters Wi specifies, for example, an associated ram position zi for one or more time points ti during a work cycle C with cycle duration Tj. The at least one time point ti within a work cycle C can vary. Optionally, each ram position zi of the relevant work parameter set Wi can be additionally assigned a parameter characterizing the ram movement, for example, a ram velocity vi at the relevant time point ti. In addition to or as an alternative to the ram velocity vi, the relevant work parameter set Wi can also include a ram acceleration.

[0058] As illustrated in Figure 3, there- Here, operating points during a work cycle C are defined by one or more sets of work parameters Wi, such as: - a first tappet position zl at a first time tl at the beginning of each work cycle C; - a second plunger position z2 at a second time t2, at which the tool part 25 arranged on the plunger 16 comes into contact with a workpiece 12 to be machined; - a third plunger position z3 at a third time t3, wherein the third plunger position z3 marks a reversal point of the movement of the plunger 16; - a fourth ram position z4 at a fourth time t4 at the end of the work cycle C, wherein this fourth ram position z4 corresponds in particular to the first ram position zl.

[0059] The ram position z is determined in a machine coordinate system that is immobile or fixed in position relative to the machine frame 13.

[0060] As explained above, in addition to the respective ram position zi, each working point defined within a work cycle C can also be assigned a parameter describing the ram movement, in the exemplary embodiment a ram velocity vi. This ensures, for example, that an excessively high impact velocity is avoided when the ram 16 or the tool part 25 strikes a workpiece 12 (second time t2 in Figure 3).

[0061] The number of defined operating points, and thus the number of operating parameter sets Wi for each work cycle C, can vary and depends on the specific work task. In a variation of Figure 3, more or fewer than four operating points can therefore be defined by each operating parameter set Wi.

[0062] Equivalent to the time points ti during a considered cycle duration T of each work cycle, a corresponding guide angle value ai of a virtual guide angle a could also be considered, where the guide angle value of the virtual guide angle a changes by 360° during a considered complete work cycle C (with cycle duration T), for example from a first guide angle value al = 0° (corresponding to the first time point tl) to a fourth guide angle value a4 = 360° (corresponding to the fourth time point t4). Analogously, the second time point t2 corresponds to a second guide angle value a2 and the third time point t3 to a third guide angle value a3 (see Figures 3 and 4).

[0063] Specifying at least one working parameter set Wi corresponds to a first process step VI of an embodiment of a process V according to the invention in the flowchart shown in Figure 9.

[0064] Based on at least one set of operating parameters Wi, a drive curve A is subsequently determined by means of the control unit 20 (second process step V2), which is referred to below as the original drive curve A for better distinction. The original drive curve A is shown schematically as an example in Figure 4. It describes a time- or guide-angle-continuous progression of the tappet position z as a function of of time or the virtual guide angle from the beginning to the end of a considered work cycle C. The original drive curve A can be determined by known methods and may, for example, be a Bézier curve and / or a spline. In the exemplary embodiment, the original drive curve A is determined such that both the temporal (or guide angle-dependent) course of the tappet position z, as well as the temporal (or guide angle-dependent) course of the tappet velocity v, and optionally also the temporal (or guide angle-dependent) course of the tappet acceleration, are continuous.

[0065] Due to the coupling of the plunger drive 17 by means of the coupling device 19, there is a relationship between the plunger position or plunger movement defined by the drive curve and a control curve of the plunger drive 17. The control curve can, for example, describe the time course of a rotational position β of an eccentric, of the at least one electric motor 18, or of another drive element of the plunger drive 17 and / or the coupling device 19. The control curve S defines the rotational speed and / or the torque of the at least one electric motor 18 at each time t during a work cycle C such that the associated drive curve A is achieved. An example of a control curve S is shown schematically as a dashed line in Figure 4.

[0066] As already explained with reference to model 30 in Figure 2, at least one load parameter L is subsequently determined based on the original drive curve A and / or the associated original control curve S, which is determined during the operation of the forming and / or stamping machine 11 using the original drive curve A or the associated original control curve S. would result in the control curve S (third process step V3).

[0067] Following this, in a fourth process step V4, it can be checked whether the maximum load L defined by the at least one load parameter L has been exceeded. max compliance is ensured. For example, the force F acting on the substrate 15 and / or the vibration x can be used as load parameters L and compared with a corresponding limit value, for example a maximum permissible force F. maxor a maximum permissible amplitude B, as already described in connection with Figures 5 and 6.

[0068] If this test reveals that the maximum load L max If the following has been observed (branching OK from the fourth process step V4), the original drive curve A can be marked as suitable for the operation of the forming and / or punching machine 11 (fifth process step V5) and later selected and used (eighth process step V8).

[0069] However, if it is found that one or more of the load parameters used L do not meet the respective assigned condition for compliance with the maximum load L max If the condition is not met (branching NOK from the fourth process step V4), the process V is continued in a sixth process step V6 and a modified drive curve A is generated. mOd is determined, which can then be used in the eighth process step V8 to operate the forming and / or stamping machine 11. Within the sixth process step V6, it is possible to use several modified drive curves A. mO to generate and select one of them for subsequent operation, in particular to maximize the productivity of the forming and / or stamping machine 11 to ensure .

[0070] This sixth process step V6 represents an independent aspect of the invention and can also be carried out independently of the other process steps as an individual process (Figure 10).

[0071] After the fifth process step V5, it can optionally be checked in a seventh process step V7 whether at least one modified drive curve A is also available. mOd is to be determined. The procedure is then continued (branch OK from the seventh process step V7) in the sixth process step V6. This allows for the selection of the possible drive curves A, A that comply with the maximum load. mO The most suitable curve is selected, for example, one that enables the highest productivity. Otherwise, the process continues with the eighth process step V8 (branching NOK from the seventh process step V7), which also follows the sixth process step V6. In the eighth process step V8, a most suitable curve (the original drive curve A or one of the determined modified drive curves A) is selected. mO d) used for the operation.

[0072] In machines known from the prior art, it was generally necessary to extend the cycle time if the original drive curve A did not meet the conditions of maximum load. Figure 4 schematically illustrates this by way of an example using an extended cycle time T* of an associated work cycle 0* with the relevant drive curve A*. However, this results in reduced productivity because the machine can only be operated at a lower stroke rate (number of strokes per unit of time) if a An extended work cycle C* with an extended cycle duration T* must be implemented. The present invention addresses this need and creates the possibility of increasing the productivity of the forming and / or stamping machine 11 while taking into account the specified maximum load L. max to optimize. For this purpose, at least one modified drive curve A is used in the sixth process step V6.mO d determined .

[0073] An exemplary procedure for determining at least one modified drive curve A mO The sixth process step V6 is illustrated by the flow diagram in Figure 10.

[0074] In a first substep V61, the original drive curve A and / or the associated original control curve S are filtered with at least one filter parameter set PF. Each predefined filter parameter set PF defines a corresponding transfer function U of the filter. In the exemplary embodiment, the filter parameter sets PF are applied to the original control curve S.

[0075] The filter used here is an FIR filter. Exemplary transfer functions U, each defined by a filter parameter set PF, are illustrated in Figure 7. Regardless of these exemplary representations, the filter parameter sets PF and the transfer functions U defined by them can generally have a low-pass, high-pass, band-pass, or band-stop characteristic.

[0076] By applying the filter parameter sets PF In a second substep V62, a modified drive curve A is used. mO d obtained. If the filter parameter sets PF are applied directly to the original drive curve A, the modified drive curves A result. mO d directly. When the filter parameter sets PF are applied to the original control curve S, a modified control curve S results in each case.mo d, based on which in turn the resulting modified drive curve A mO d can be calculated. The relationship of a modified control curve S mO d and an associated modified drive curve A mO d corresponds to the relationship between the original control curve S and the original drive curve A, as already explained with reference to Figure 4.

[0077] Each filter parameter set PF is configured to modify the curve profile or shape of the original drive curve A between the first guide angle value al (corresponding to the first time tl) and the fourth guide angle value a4 (corresponding to the fourth time t4) without extending the cycle time T – unlike in the prior art according to Figure 4. The at least one filter parameter set PF is intended to dampen vibrations, particularly at one (or more or all) natural frequencies of the forming and / or stamping machine 11 (especially of the machine frame 13).

[0078] In a third substep V63, it is checked whether at least one modified drive curve A mO d the requirements of at least one working parameter set Wi are met. Should this not be the case (branch NOK from the third substep V63), the relevant modified parameter is applied in a fourth substep V64 in the exemplary embodiment. ornamented drive curve A mO d is corrected so that it meets the requirements of at least one set of work parameters Wi. Alternatively, a modified drive curve A could be used. mO d, which does not meet the conditions of at least one work parameter set Wi, will no longer be considered in the further course of events. A correction in the fourth substep V64 is required for the modified drive curves A mO d not required, which meet the conditions of at least one work parameter set Wi (branch OK from the third substep V63) .

[0079] The modified drive curves A mO d, which meet the requirements of at least one work parameter set Wi, are subsequently used in a fifth substep V65 and are calculated for each modified drive curve A mOd the resulting at least one load parameter L is determined, so that it can subsequently be checked whether the requirements for the maximum load L are met. max must be adhered to (sixth substep V66).

[0080] In the sixth substep V66, it is determined that a modified drive curve A mO d the conditions of the permissible maximum load are met (branch OK from the sixth substep V66), this modified drive curve A mO d marked or added to a group that contains modified drive curves A usable in the further course of the process mO d contains (seventh substep V67) .

[0081] Subsequently, in an eighth substep (V68), it is checked whether a termination criterion is met. If this is not the case (branch NOK from the eighth substep V68), the procedure continues again in the first substep (V61), with the starting point for the filtering and further procedure execution now being the value from the previous substep. Loop determined modified drive curves A mO d serve, at least those that are not marked in the seventh substep V67 or belong to the group of usable modified drive curves A mO d were added.

[0082] Once the termination criterion defined in the eighth substep V68 is met, the determination of the modified drive curves A will begin. mO d is completed and in the seventh process step V7 the modified drive curve A can be used. mOd are selected and used which enables the best possible operation of the forming and / or stamping machine 11, for example allowing the highest productivity.

[0083] The termination criterion defined in the eighth substep V68 can be met, for example, if a maximum number of loops have been executed and / or if no specified minimum change has occurred between two successive loops, such as no minimum increase in productivity.

[0084] The invention relates to a method V and a device 10 for controlling a ram drive 17 of a cyclically operating forming and / or stamping machine 11. For the execution of each work cycle C, operating points of a ram 16 are defined by at least one set of operating parameters Wi, and a drive curve A for the ram 16 is subsequently determined from these. Based on this drive curve A, it is checked whether a predetermined permissible maximum load L is exceeded. max This is adhered to. If this should not be the case, at least a modified drive curve A will be used. mO d using a filter, for example An FIR filter is determined, which is applied to the drive curve A or a corresponding control curve S. If several modified drive curves A are used, mO d determined, can from this the modified drive curve A mOd should be selected which enables the most suitable operation for the application, for example the highest productivity or stroke rate of the forming and / or punching machine 11. Reference character list: 10 Device 11 Forming and / or stamping machine 12 workpieces 13 machine frame 14 Spring-damper element 15 Subsurface 16 pestles 17 plunger drive 18 Electric motor 19 Coupling device 20 Control unit 21 local control unit 22 external control unit 25 Tool part on the plunger 26 Tool part on the machine frame 30 Model a Guide angle ai Guide angle value i ( i=l , 2 , 3 , . . . n) ß Rotation position A drive curve A* Drive curve for extended cycle duration A mO d modified drive curve B. Amount of the maximum permissible amplitude C work cycle C* Working cycle with extended cycle duration d damping constant E suggestion f frequency F force F max maximum permissible force K spring constant L Load parameters L max Maximum load m mass PF filter parameter set R working direction S control curve S m od modified control curve t time ti time ( i=l , 2 , 3 , . . . n) T Cycle duration T* extended cycle duration U Filter parameter set v Piston velocity vi Piston velocity at a time ti V Procedure VI first procedural step V2 second procedure step V3 third process step V4 fourth process step V5 fifth process step V6 sixth process step V7 seventh process step V8 eighth process step V61 first substep V62 second substep V63 third substep V64 fourth substep V65 fifth substep V66 sixth substep V67 seventh substep V68 eighth substep Wi working parameter set (i=l, 2, 3, . . . n) x oscillation z ram position zi ram position at a time ti

Claims

Patent claims:

1. Method (V) for controlling a ram drive (17) for a ram (16) of a cyclically operating forming and / or stamping machine (11) which is movable in a working direction (R) on a machine frame (13) , wherein the method (V) comprises: - Specifying at least one set of working parameters (Wi) which specifies a ram position (zi) and / or a ram movement (vi) at a time (ti) during a working cycle (C), - Determining a drive curve (A) for controlling the tappet drive (17) based on the at least one working parameter set (Wi) , wherein the drive curve (A) specifies the tappet position (z) and / or tappet movement (v) during the entire working cycle (C), - Determine at least one load parameter (L) resulting from the operation of the forming and / or stamping machine (11) with the drive curve (A), - Check, using at least one load parameter (L), whether a specified permissible maximum load (L) max ) is adhered to, - Determine at least one modified drive curve (A mO d) by filtering the drive curve (A) and / or a control curve (S) describing the drive curve (A) with at least one filter parameter set (PF) , if the permissible maximum load (L max ) was not adhered to, - Using the drive curve (A) or the modified drive curve (A) mO d) or one of several modified drive curves (A mO d) selected modified drive curve (A mO d) for controlling the plunger drive (17) .

2. The method according to claim 1, wherein the at least one modified drive curve (A) is determined by mOd) the control curve (S) is filtered, which specifies a rotational position (ß) and / or a rotary movement and / or a torque of the tappet drive (17) during the entire working cycle (C).

3. The method of claim 2, wherein, based on each filtered control curve (S), the resulting modified drive curve (A) mO d) is determined.

4. Method according to one of the preceding claims, wherein for each determined modified drive curve (A mO d) is checked whether the at least one The defined specifications of the work parameter set (W) are met.

5. Method according to claim 4, wherein at least one modified drive curve (A mO d) , which does not meet the requirements defined by the at least one set of work parameters (W), is corrected so that the requirements defined by the set of work parameters (W) are met.

6. Method according to claim 4 or 5, wherein for each modified drive curve (A mO d) , which meets the requirements defined by the work parameter set (W), for which at least one load parameter (L) is determined, which is determined by the operation of the forming and / or Punching machine (11) with the modified drive cam (A mO d) results, and it is checked on the basis of at least one load parameter (L) whether the permissible maximum load (L) max ) is adhered to.

7. Method according to claim 6, wherein the modified drive curve (A mO d) is used to control the plunger drive (17), which determines the permissible maximum load (L max ) complies with and enables the highest productivity of the forming and / or stamping machine (11).

8. Method according to any of the preceding claims, wherein the filtering is carried out using an FIR filter.

9. Method according to one of the preceding claims, wherein a force (F) acting on a substrate (15) is used as the load parameter (L).

10. Method according to one of the preceding claims, wherein a vibration (x) of a component of the forming and / or stamping machine (11) , in particular a spring-damper element (14) , is used as the load parameter (L).

11. Method for determining at least one usable modified drive curve (A mO d) based on an original drive curve (A) and / or an original control curve (S) describing the original drive curve (A), wherein the original drive curve (A) defines a ram position (z) and / or a ram movement (v) during an entire work cycle (C) of a cyclically operating forming and / or Punching machine (11) specifies and for controlling a ram drive (17) of the forming and / or punching machine (11) is usable, the method having: - Providing at least one set of working parameters (Wi) that specifies a ram position (zi) and / or a ram movement (vi) at a time (ti) during a working cycle (C), - Determine at least one load parameter (L) resulting from the operation of the forming and / or stamping machine (11) with the drive curve (A), - Providing the original drive curve (A) and / or the original control curve (S) describing the original drive curve (A), - Provide at least one set of filter parameter (PF) , - Determination of at least one modified drive curve (A mOd) by filtering an original drive curve (A) and / or an original control curve (S) describing the original drive curve (A) with the filter parameter set (PF) or with one filter parameter set (PF) each from several filter parameter sets (PF) , - Check, using at least one load parameter (L), whether a specified permissible maximum load (Lmax) is adhered to, and check, using at least one work parameter set (Wi), whether the at least one modified drive curve (A mO d) meets the specifications of at least one working parameter set (Wi) - Marking each determined modified drive curve (A mO d) as usable, where the test has shown that the specified maximum permissible load (Lmax) and the specifications of at least one set of working parameters (Wi) are complied with.

12. Computer program product comprising program code stored in a memory which, when executed in a processor of a control unit (20) of a cyclically operating forming and / or stamping machine (11), causes the control unit (20) to execute a method according to one of the preceding claims.

13. Device comprising (10): - a cyclically operating forming and / or stamping machine (11) with a machine frame (13) , with a ram drive (17) and with a ram (16) mounted on the machine frame (13) so as to be movable in one working direction (R) , - a control device (20) configured to control the plunger drive (17) and to perform the following procedure: o specifying at least one working parameter set (Wi) which specifies a plunger position (zi) and / or a plunger movement (vi) at a time (ti) during a working cycle (C), Determining a drive curve (A) for controlling the ram drive (17) based on the at least one working parameter set (Wi), wherein the drive curve (A) specifies the ram position (z) and / or ram movement (v) during the entire working cycle (C); determining at least one load parameter (L) resulting from the operation of the forming and / or punching machine (11) with the drive curve (A); checking, based on the at least one load parameter (L), whether a specified permissible maximum load (L) max ) is adhered to, determining at least one modified drive curve (A mO d) by filtering the drive curve (A) and / or a control curve (S) describing the drive curve (A) with at least one filter parameter set (PF) , if the permissible maximum load (L max ) was not adhered to, use of the drive curve (A) or the modified drive curve (A) mOd) or one of several modified drive curves (A mO d) selected modified drive curve (A mO d) for controlling the plunger drive (17) .

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