Forming machine for forming workpieces and a method for doing so

Abstract

The invention relates to a forming machine (5) for forming workpieces (15), more particularly a bending machine for bending workpieces, more particularly sheet-type workpieces, comprising a first machine part (6), a second machine part (7), a controller (8) and a drive system for moving the first machine part (6) relative to the second machine part (7) and for producing the forming force, the drive system having a drive train (4) formed by at least two drive components (1, 2, 3). The forming machine is characterized in that at least one drive parameter (11) of a first drive component (1) of the drive train (4) and at least one drive parameter (12) of a second drive component (2) of the drive train (4) can be adjusted by the controller (8). A routine (9) for optimizing the energy efficiency and / or the degree of efficiency of the drive system is stored in the controller (8), and in at least one operating mode of the forming machine (5) the at least one drive parameter (11) of the first drive component (1) and the at least one drive parameter (12) of the second drive component (2) are specified by the routine (9).

Description

[0001] FORMING MACHINE FOR FORMING WORKPIECES AND A METHOD THEREFOR

[0002] The invention relates to a forming machine for forming workpieces according to the preamble of claim 1.

[0003] To generate the required pressing force in forming machines, a drive train is required, which typically comprises several drive components. In bending presses, the drive components usually consist of a motor, a motor-driven hydraulic pump, and a cylinder operatively connected to the hydraulic pump.

[0004] The disadvantage of the current technology is that the energy consumption of such a drive system – considered over many processing cycles – is very high. Therefore, there is a need to reduce energy consumption and create a forming machine that can be operated more energy-efficiently and therefore more cost-effectively. Such a forming machine should preferably be equipped with simple and sustainable measures. The machining quality of the workpieces to be formed should remain consistently high.

[0005] This object is achieved by a forming machine and a method for operating a forming machine according to the claims.

[0006] The device according to the invention thus relates to a forming machine for forming workpieces, in particular a bending machine for bending workpieces, in particular sheet-metal workpieces, comprising a first machine part, a second machine part, a controller and a drive system for moving the first machine part relative to the second machine part and for generating the forming force, wherein the drive system has a drive train formed from at least two drive components.

[0007] According to the invention, at least one drive parameter of a first drive component of the drive train and at least one drive parameter of a second drive component of the drive train are adjustable by the controller, wherein a routine for optimizing the energy efficiency and / or the efficiency of the drive system is stored in the controller and the at least one drive parameter of the first drive component and the at least one drive parameter of the second drive component are predetermined by the routine in at least one operating mode of the forming machine.

[0008] By allowing the drive parameters to be adjusted depending on the application, as well as by providing an optimization routine for selecting and / or determining suitable drive parameters for different applications, the energy efficiency and thus the efficiency of the drive system can be increased. The measure according to the invention thus prevents unnecessary energy waste.

[0009] The optimization routine is configured to select and / or determine an optimal combination of drive parameters for the first and second drive components for each application, with regard to efficiency. This means that the optimization routine specifies different drive parameters for different application cases (defined, for example, by the properties of the workpiece and / or the desired forming process), which are then used to control the respective drive components (by the controller).

[0010] The optimization routine is stored in the control system of the forming machine and can be implemented in the form of a program and / or an algorithm. The routine can include various input variables that characterize the application. Using a (calculation) rule and / or an assignment (also stored in the control system), e.g., in the form of a table or multidimensional matrix, the routine determines output variables that correspond to the drive parameters of the drive components or from which the latter can be derived.

[0011] This means that the combination of the first and second drive components (or possibly further drive components) or even the entire drive train can be operated in the range of its optimal efficiency in every application.

[0012] The routine thus determines the optimal operating point by specifying the drive parameters – usually based on input parameters such as workpiece parameters and / or bending parameters and / or the operating phase. In other words, the required controller data for the drive components are adjusted accordingly to achieve this optimal operating point.

[0013] Each workpiece to be formed places different demands on a forming or bending machine, meaning the required forces can vary. In addition, the speeds of the movable machine part can be freely selected for different operating phases and / or different holding times can be freely programmed. The invention provides the appropriate drive parameters for this multitude and variety of applications.

[0014] To generate the required pressing force in forming machines, a drive train is required, which typically comprises several drive components. A special type of forming machine is a hydraulic bending machine, in which the required forming force is generated using the following drive components: a motor, a motor-driven hydraulic pump, and a cylinder operatively connected to the hydraulic pump.

[0015] In servo-hydraulically driven bending machines, the servo motor and servo controller are of particular interest. For example, an efficiency matrix for the drive train can be created from the individual efficiency values ​​of the individual drive components. If the drive is now operated in optimized ranges instead of at the usual operating points, energy consumption can be significantly reduced.

[0016] Energy can also be saved with a position-controlled stop of one of the machine components. Since such a position-controlled stop requires less pressure and the motor is running at a low speed during this time, efficiency is low. This means that the stop time in the position control should be as short as possible. Thus, in a preferred embodiment, a drive parameter of the first and / or second drive component is the time period (stop time) available for a position-controlled stop of one of the machine components.

[0017] A preferred embodiment is characterized in that the routine is set up to select and / or determine the at least one drive parameter of the first drive component and the at least one drive parameter of the second drive component depending on at least one workpiece parameter, in particular the workpiece thickness and / or the workpiece material and / or the workpiece shape, and / or depending on at least one bending parameter, in particular the bending angle and / or the immersion depth and / or the forming force, and / or depending on an operating phase of the forming machine, in particular the feed phase (also called rapid phase) and / or the forming phase. The optimization routine determines the drive parameters - optimized with regard to energy efficiency and / or efficiency - based on input variables that define the respective application.In this way, the routine can respond individually to each application and output optimized parameters. In other words, the routine determines those drive parameters that result in the highest energy efficiency or efficiency under the given conditions (workpiece parameters, bending parameters, and / or operating phase).

[0018] A preferred embodiment is characterized in that at least one parameter assignment, in particular in the form of a data set and / or a calculation rule and / or a function, is stored in the controller, which assigns at least one drive parameter of the first drive component and at least one drive parameter of the second drive component to workpiece parameters and / or bending parameters and / or operating phases of the forming machine. This parameter assignment can be included in the routine itself and stored, for example, in the form of a table, matrix and / or an algorithm. The parameter assignment is preferably a multi-dimensional matrix in which, for example, each combination of input variables (workpiece parameters, bending parameters and / or operating phase) is assigned a combination of (optimized) drive parameters. The parameter assignment can be determined in advance orbe programmed and take into account all relevant factors influencing the efficiency of the drive train or the combination of individual drive components.

[0019] A preferred embodiment is characterized in that the routine comprises an assignment, preferably in the form of an efficiency matrix, which assigns combinations of at least one drive parameter of the first drive component and at least one drive parameter of the second drive component to an efficiency of the combination of at least the first drive component and the second drive components. In this way, the routine can search for the highest efficiency and, based on this, select the optimal combination of drive parameters. Of course, other drive components and their drive parameters can also be considered here, so that not only a 2-dimensional, but also a multi-dimensional matrices could be provided.

[0020] A preferred embodiment is characterized in that the routine is configured to select, for given workpiece parameters and / or given bending parameters and / or given operating phase, those drive parameters of the first drive component and those drive parameters of the second drive component for which the efficiency of the combination of at least the first drive component and the second drive components and / or the efficiency of the entire drive train is greater than 0.8 and / or has a maximum. This criterion ensures that the forming machine is always aligned to the optimal operating point, thereby minimizing energy consumption.

[0021] A preferred embodiment is characterized in that the forming machine comprises at least one sensor for detecting a drive variable, in particular a torque, a pressure, a forming force and / or a position of the first machine part relative to the second machine part, and / or at least one sensor for detecting a workpiece property (e.g. geometry, position, degree of deformation, etc.), in particular before and / or during the forming process, wherein the at least one sensor is communicatively connected to the controller and the sensor data of the at least one sensor and / or (a) variable(s) derived from the sensor data are (an) input variable(s) of the routine. The sensor(s) provide the optimization routine with additional information about the operating sequence or the forming process, whereby the drive parameters can be adapted even better to the respective situation.Sensor values ​​can also be part of the previously mentioned (parameter) assignments.

[0022] A preferred embodiment is characterized in that the forming machine has at least one input interface for entering workpiece parameters and / or bending parameters, wherein the workpiece parameters and / or bending parameters are input variables of the routine. The input interface allows the parameters defining the application (i.e., the specified framework conditions for the forming process) to be fed into the optimization routine either automatically or by an operator (in the latter case, a user interface).

[0023] A preferred embodiment is characterized in that the routine is configured to also change at least one drive parameter of the second drive component when changing at least one drive parameter of the first drive component. This results in a dynamic or flexible adaptation, which is based on the inventive idea that, in energy efficiency optimization, the (optimal) drive parameters are interdependent or must be adjusted interdependently.

[0024] A preferred embodiment is characterized in that the routine is configured to adjust at least one drive parameter of at least one drive component if the efficiency of the combination of at least the first and second drive components is less than a predetermined value and / or falls below a predetermined value during operation of the forming machine. In this way, an immediate response to an emerging situation is possible.

[0025] A preferred embodiment is characterized in that at least two operating phases, in particular a forming phase and a feed phase (sometimes also called rapid phase), are mapped in the control system, which differ in the forming force and / or feed speed between the first and second machine parts, wherein the routine is set up to specify - depending on the respective operating phase - different drive parameters of the first drive component of the drive train and different drive parameters of a second drive component of the drive train.

[0026] A preferred embodiment is characterized in that the drive train comprises a cylinder-piston unit which can be pressurized by the first drive component and / or second drive component.

[0027] A preferred embodiment is characterized in that the first drive component and the second drive component are connected in series in the drive train. It is preferred if the first drive component (e.g., motor) drives the second drive component (e.g., pump). It is particularly preferred if the second drive component subsequently drives the cylinder-piston unit.

[0028] A preferred embodiment is characterized in that the first drive component comprises a motor, preferably a servo motor, wherein preferably a drive parameter of the first drive component that can be adjusted by the controller according to the routine is the speed and / or the torque of the motor.

[0029] A preferred embodiment is characterized in that the second drive component comprises a pump driven by the motor, in particular a control pump, wherein preferably a drive parameter of the second drive component that can be adjusted by the controller according to the routine is the delivery volume flow, and / or that the second drive component comprises a mechanical transmission, wherein preferably a drive parameter of the second drive component that can be adjusted by the controller according to the routine is the transmission ratio of the transmission.

[0030] The flow rate depends, among other things, on the pump's geometric displacement. Therefore, control pumps with variable geometric displacement can be used. In this case, the drive parameter of the second drive component can be the pump's geometric displacement.

[0031] A preferred embodiment is characterized in that the routine is configured to reduce the delivery volume flow of the pump comprised by the second drive component in the course of increasing the speed of the motor comprised by the first drive unit and / or to increase the delivery volume flow of the pump comprised by the second drive component in the course of reducing the speed of the motor comprised by the first drive unit.

[0032] A preferred embodiment is characterized in that at least one drive parameter of a third drive component of the drive train can be adjusted by the controller, wherein the at least one drive parameter of the third drive component is predetermined by the routine in at least one operating mode of the forming machine.

[0033] A preferred embodiment is characterized in that the third drive component comprises a valve, wherein preferably a drive parameter of the third drive component that can be adjusted by the controller is the valve position.

[0034] A preferred embodiment is characterized in that the first machine part and / or the second machine part comprises a forming tool holder and / or at least one forming tool. For example, the first (in particular movable) machine part can comprise the upper tool holder and optionally at least one upper tool inserted therein (e.g. in the form of a punch), and the second (in particular stationary) machine part can comprise the lower tool holder and optionally at least one lower tool inserted therein (e.g. in the form of a die or a forging die).

[0035] The object is also achieved by a method for operating a forming machine for forming workpieces, in particular a bending machine for bending workpieces, in particular sheet-metal workpieces, wherein the forming machine comprises a first machine part, a second machine part, a control system and a drive system for moving the first machine part relative to the second machine part and for generating the forming force, wherein the drive system has a drive train formed from at least two drive components, characterized in that at least one drive parameter of a first drive component of the drive train and at least one drive parameter of a second drive component of the drive train are adjusted by the control system,wherein a routine for optimizing the energy efficiency and / or the efficiency of the drive system is stored in the controller, and the at least one drive parameter of the first drive component and the at least one drive parameter of the second drive component are specified by the routine in at least one operating mode of the forming machine. A preferred embodiment is characterized in that the forming machine is designed according to one of the previously described embodiments.

[0036] For a better understanding of the invention, it is explained in more detail using the following figures.

[0037] They show in a highly simplified, schematic representation:

[0038] Fig. 1 shows an embodiment of a forming machine according to the invention;

[0039] Fig. 2 shows the principle of optimization according to an embodiment of the invention;

[0040] Fig. 3 shows the efficiency of a drive train as a function of the speed of a

[0041] Pump motor at different torques (in % of the rated torque) as well as in rapid traverse and

[0042] Fig. 4 shows a schematic representation of an efficiency matrix relating to the drive train, with each box containing an efficiency for a combination of torque (in % of the rated torque) and speed.

[0043] By way of introduction, it should be noted that in the variously described embodiments, identical parts are provided with identical reference symbols or component designations. The disclosures contained throughout the description can be applied analogously to identical parts with identical reference symbols or component designations. Furthermore, the positional information chosen in the description, such as top, bottom, side, etc., refers to the directly described and illustrated figure, and these positional information must be applied analogously to the new position in the event of a change in position.

[0044] The exemplary embodiments show possible embodiments. It should be noted at this point that the invention is not limited to the specifically illustrated embodiments. Rather, various combinations of the individual embodiments are also possible. This variation possibility, based on the teaching of technical action based on the invention in question, lies within the skill of the person skilled in the art. The scope of protection is determined by the claims. However, the description and drawings must be used to interpret the claims. Individual features or combinations of features from the various exemplary embodiments shown and described may represent independent inventive solutions in themselves. The problem underlying the independent inventive solutions can be derived from the description.

[0045] All information on value ranges in this description is to be understood as including any and all sub-ranges thereof, e.g. the information 1 to 10 is to be understood as including all sub-ranges starting from the lower limit of 1 and the upper limit of 10, ie all sub-ranges begin with a lower limit of 1 or greater and end with an upper limit of 10 or less, e.g. 1 to 1.7, or 3.2 to 8.1, or 5.5 to 10.

[0046] For the sake of clarity, it should finally be pointed out that, in order to better understand the structure, some elements have been shown out of scale and / or enlarged and / or reduced in size.

[0047] Fig. 1 shows a forming machine 5 for forming workpieces 15 in the form of a bending machine for bending workpieces—in particular sheet metal workpieces. The forming machine is preferably a metal forming machine for forming metal workpieces. These can be, for example, bending presses, swivel bending machines, or press brakes. Forming machines that imprint a three-dimensional and / or complex shape on the workpiece in a forming curtain are also encompassed by the invention.

[0048] Forming machine 5 comprises a first machine part 6 and a second machine part 7, as well as a drive system for moving the first machine part 6 relative to the second machine part 7. The drive system effects the relative movement and generates the forming force. It has a drive train 4 formed from at least two drive components 1, 2, 3.

[0049] A controller 8 can adjust at least one drive parameter 11 of a first drive component 1 of the drive train 4 and at least one drive parameter 12 of a second drive component 2 of the drive train 4. In other words, the controller controls the drive components by setting the drive parameters of the drive components.

[0050] In the illustrated embodiment, the first drive component 1 comprises a motor, preferably a servomotor. A drive parameter 11 of the first drive component 1 that can be adjusted by the controller 8 according to routine 9 can be, for example, the speed and / or the torque of the motor. According to the embodiment of Fig. 2, the second drive component 2 comprises a pump driven by the motor, in particular a control pump. A drive parameter 12 of the second drive component 2 that can be adjusted by the controller 8 according to routine 9 can be, for example, the delivery volume flow.

[0051] Alternatively, for example, the second drive component 2 could comprise a mechanical transmission, wherein preferably a drive parameter 12 of the second drive component 2 that can be adjusted by the controller 8 according to the routine 9 is the transmission ratio of the transmission.

[0052] The first drive component 1 and the second drive component 2 are connected in series in the drive train 4, with the first drive component 1 (here the motor) driving the second drive component 2 (here the pump). Subsequently, the second drive component 2 drives the cylinder-piston unit 14, which acts on the first machine part 1. Here, the drive train 4 thus comprises a cylinder-piston unit 14, which can be pressurized by the first drive component 1 and / or the second drive component 2.

[0053] In the illustrated embodiment, at least one drive parameter 13 of a third drive component 3 of the drive train 4 is adjustable by the controller 8, wherein the at least one drive parameter 13 of the third drive component 3 is predetermined in at least one operating mode of the forming machine 5 by the routine 9. The third drive component 3 can, for example, comprise a valve, wherein preferably one drive parameter 13 of the third drive component 3 adjustable by the controller 8 according to the routine 9 is the valve position.

[0054] It should be noted at this point that the combination of motor and pump represents merely preferred embodiments, and that other combinations of drive components forming a drive train are also possible. Such controllable drive components can, in particular, be mechanical, hydraulic, pneumatic, or electromagnetic in nature. Although the present invention is described with reference to the combination of motor and pump, the inventive principle can equally be applied to other combinations of drive components.

[0055] A routine 9 for optimizing the energy efficiency and / or efficiency of the drive system is now stored in said controller 8. The at least one drive parameter 11 of the first drive component 1 and the at least one drive parameter 12 of the second drive component 2 are specified by this optimization routine 9 in at least one operating mode of the forming machine 5.

[0056] The routine 9 can - as shown schematically in Fig. 2 - in particular be set up or programmed to select and / or determine the at least one drive parameter 11 of the first drive component 1 and the at least one drive parameter 12 of the second drive component 2 as a function of at least one workpiece parameter 16, in particular the workpiece thickness and / or the workpiece material and / or the workpiece shape, and / or as a function of at least one bending parameter 17, in particular the bending angle and / or the immersion depth and / or the forming force, and / or as a function of an operating phase 18 of the forming machine 5, in particular the feed phase and / or the forming phase.

[0057] In this case, at least one parameter assignment, in particular in the form of a data set and / or a calculation rule and / or a function, can be stored in the controller 8, which assigns at least one drive parameter 11 of the first drive component 1 and at least one drive parameter 12 of the second drive component 2 to workpiece parameters 16 and / or bending parameters 17 and / or operating phases 18 of the forming machine 5. In the case of a data set, e.g. in the form of a (multi-dimensional) table or matrix, values ​​for the respective drive parameters 11, 12, 13 can be assigned to each combination of these input variables (workpiece parameters 16 and / or bending parameters 17 and / or operating phases 18). In the case of a function or calculation rule, such an assignment can at least partially also contain analytical relationships.In any case, such a parameter assignment can be schematically represented as follows: (yn, yi2, yn) = F (xi6, xi7, Xis), where yn, yi2, yi3 represent the values ​​of the drive parameters 11, 12, 13 and xi6, xn, Xis the values ​​of the input variables 16, 17, 18.

[0058] Alternatively or additionally, the routine 9 may comprise an assignment, preferably in the form of an efficiency matrix, which includes combinations of at least one drive parameter

[0059] 11 of the first drive component 1 and at least one drive parameter 12 of the second drive component 2 each assigns an efficiency of the combination of at least the first drive component 1 and the second drive component 2. Such an efficiency matrix (for a combination of motor and pump) is shown schematically in Fig. 4. This efficiency matrix relates to a drive train, with the individual boxes each containing an efficiency for a combination of torque (in % of the rated torque) and speed of the drive motor. The oval area extending along the diagonal - from top left to bottom right - contains efficiency values ​​that are higher than those outside the delimited oval area. For example, the delimited area can be laid out so that it only contains efficiencies above 0.8.The hatched boxes with the corresponding arrows indicate that the efficiency of the drive train can be increased by changing (here: reducing) the torque and changing (here: increasing) the speed. While the torque correlates with the pump's flow rate (and thus with the drive parameter),

[0060] 12 of the second drive component 2 is adjustable), the speed (as drive parameter 11 of the first drive component 1) can be adjusted directly on the motor. Routine 9 can now use the efficiency matrix to select those values ​​for drive parameters 11, 12 that correspond to the highest efficiencies.

[0061] Fig. 3 shows the efficiency of the motor-pump combination as a function of the motor speed and for different torques (100%, 75%, and 50% of the rated torque) and in rapid traverse E. The torque is a measure of the pump flow rate of a control pump and thus correlates with the drive parameter 12 of the second drive component.

[0062] The arrow pointing straight upwards shows that, at a constant speed, efficiency can be increased by reducing the torque (which is achieved by changing the flow rate). A simultaneous increase in speed and reduction in torque (which is achieved by changing the flow rate) also leads to a significant increase in efficiency during the forming phase (see the arrow pointing diagonally upwards to the right). These relationships (which naturally depend on the respective combination of drive components) are mapped directly or indirectly in the routine or the data sets the routine uses.

[0063] The routine can thus be configured to reduce the delivery volume flow of the pump comprised by the second drive component (2) in at least one operating mode of the forming machine 5 as the speed of the motor comprised by the first drive unit 1 increases and / or to increase the delivery volume flow of the pump comprised by the second drive component 2 as the speed of the motor comprised by the first drive unit 1 decreases.

[0064] In this case, the routine 9 can be set up in particular to select, for given workpiece parameters 16 and / or given bending parameters 17 and / or given operating phase 18, those drive parameters 11 of the first drive component 1 and drive parameters 12 of the second drive component 2 for which the efficiency of the combination of at least the first drive component 1 and the second drive component 2 and / or the efficiency of the entire drive train 4 is greater than 0.8 and / or has a maximum.

[0065] 1 and 2 also indicate that the forming machine 5 may comprise at least one sensor 10 for detecting a drive variable, in particular a torque, a pressure, a forming force, and / or a position of the first machine part 6 relative to the second machine part 7, and / or at least one sensor 20 for detecting a workpiece property, in particular before and / or during the forming process, wherein the at least one sensor 10, 20 is communicatively connected to the controller 8, and the sensor data of the at least one sensor 10, 20 and / or a variable derived from the sensor data are input variables of the routine 9. The forming machine 5 may—as shown in Fig. 1—have at least one input interface 19 for entering workpiece parameters 16 and / or bending parameters 17, wherein the workpiece parameters 16 and / or bending parameters 17 are input variables of the routine 9.

[0066] The routine 9 can in particular be configured to also change at least one drive parameter 12 of the second drive component 2 in the course of changing at least one drive parameter 11 of the first drive component 1.

[0067] The routine 9 is preferably configured or programmed to adapt at least one drive parameter 11, 12, 13 of at least one drive component 1, 2, 3 if the efficiency of the combination of at least the first and second drive components 1, 2 is less than a predetermined value and / or falls below a predetermined value during operation of the forming machine 5.

[0068] In the control 8, at least two operating phases, in particular a forming phase (i.e. the actual forming process) and a feed phase (in which at least one of the machine parts 1, 2 does not act on the workpiece; also called rapid phase) can be mapped, which differ in the forming force and / or the feed speed between the first and second machine parts 6, 7, wherein the routine 9 is set up to specify different drive parameters 11 of the first drive component 1 of the drive train 4 and different drive parameters 12 of a second drive component 2 of the drive train 4 depending on the respective operating phase.

[0069] The first machine part 6 and / or the second machine part 7 can each comprise a forming tool holder and / or at least one forming tool (preferably held by the forming tool holder).

[0070] Finally, the aspects described above can also be implemented within the framework of a method for operating a forming machine 5.

[0071] Finally, the potential of the invention is described using the example of a (servo) motor:

[0072] The downward movement of the first machine part 1 (e.g., the press beam) is driven by its mass. Control is achieved through regenerative braking by the (servo) motor. This allows small amounts of energy to be fed back into the intermediate circuit. During the upward movement of the first machine part 1 in the range of maximum speed, higher pressures (e.g., in the range of approximately 120 bar) are required (approximately 1 / 3 of the maximum force). The speed can be selected by the operator. In one example, the motor always runs at an optimal efficiency (>95%) at a maximum speed of 220 mm / s and one-third of the maximum force.

[0073] The position-controlled stop of the axis requires a lower pressure (e.g. in the range of approximately 70 bar, which can correspond to 1 / 4 of the maximum force). Since the motor is running at a low speed at this time (e.g. a speed of < 100 min 1 ), the efficiency is low (<60%). This means that the stopping time in the position control should be as short as possible.

[0074] During the forming phase, the required force depends on the workpiece and the selected tools and can range from 5% to 100% of the maximum force. The speed can be selected by the operator and can, for example, be between 1 and 10 mm / s or between 1 and 25 mm / s. However, the control can temporarily increase the motor speed to higher speeds (e.g., to a maximum of 2200 rpm). 1 ). For this reason, the engine does not always operate at its optimal efficiency. Efficiency drops significantly, especially when driving very slowly or applying very high forces.

[0075] There are significant energy savings opportunities in this area if a way can be found to always operate the pump in a range where efficiency is optimal. For example, hydraulic accumulators could be used for this. Adjusting the press speed could be a first step.

[0076] The example of the hydraulic pump also shows that there are areas in which the pump can work very efficiently, while other areas must be avoided at all costs.

[0077] Finally, the combination of the first drive component and the second drive component is particularly interesting, which has already been schematically shown in the efficiency matrix of Fig. 4.

[0078] The pairing of a variable speed pump and a servo motor appears particularly suitable. In this case, the operating point could be selected more or less freely at an unchanged speed. At this point, reference is again made to Fig. 3, which shows the efficiency as a function of the motor speed and for various torques (100%, 75% and 50% of the rated torque) and at rapid traverse E. The arrow pointing straight upwards shows that - at a constant speed - the efficiency can be increased by reducing the torque (which is achieved by changing the pump flow rate). A simultaneous increase in speed and reduction in torque (which is achieved by changing the pump flow rate) also leads to a significant increase in efficiency during the forming phase (see the arrow pointing diagonally upwards to the right).

[0079] Reference symbol list

[0080] 1 first drive component

[0081] 2 second drive component

[0082] 3 third drive component

[0083] 4 Drivetrain

[0084] 5 U forming machine

[0085] 6 first machine part

[0086] 7 second machine part

[0087] 8 Control

[0088] 9 Routine

[0089] 10 Sensor

[0090] 11 Drive parameters

[0091] 12 drive parameters

[0092] 13 drive parameters

[0093] 14 cylinder piston unit

[0094] 15 Workpiece

[0095] 16 workpiece parameters

[0096] 17 bending parameters

[0097] 18 Operating phase

[0098] 19 Input interface

[0099] 20 sensors

[0100] E Rapid phase

Claims

P a t e n t a n s p r ü c h e 1. Forming machine (5) for forming workpieces (15), in particular a bending machine for bending workpieces, especially sheet metal workpieces, comprising a first machine part (6), a second machine part (7), a control system (8) and a drive system for moving the first machine part (6) relative to the second machine part (7) and for generating the forming force, wherein the drive system has a drive train (4) formed from at least two drive components (1, 2, 3), characterized in that at least one drive parameter (11) of a first drive component (1) of the drive train (4) and at least one drive parameter (12) of a second drive component (2) of the drive train (4) are adjustable by the control system (8),wherein the control (8) contains a routine (9) for optimizing the energy efficiency and / or the efficiency of the drive system and the routine (9) specifies at least one drive parameter (11) of the first drive component (1) and the at least one drive parameter (12) of the second drive component (2) in at least one operating mode of the forming machine (5).

2. Forming machine according to claim 1, characterized in that the routine (9) is set up depending on at least one workpiece parameter (16), in particular the workpiece thickness and / or the workpiece material and / or the workpiece shape, and / or depending on at least one bending parameter (17), in particular the bending angle and / or the immersion depth and / or the forming force, and / or depending on an operating phase (18) of the forming machine (5), in particular the feed phase and / or the forming phase, to select and / or determine at least one drive parameter (11) of the first drive component (1) and at least one drive parameter (12) of the second drive component (2).

3. Forming machine according to claim 1 or 2, characterized in that the routine (9) comprises at least one parameter assignment, in particular in the form of a data set and / or a calculation rule and / or a function, which assigns to workpiece parameters (16) and / or bending parameters (17) and / or operating phases (18) of the forming machine (5) at least one drive parameter (11) of the first drive component (1) and at least one drive parameter (12) of the second drive component (2).

4. Forming machine according to one of the preceding claims, characterized in that the routine (9) comprises an assignment, preferably in the form of an efficiency matrix, which assigns to combinations of at least one drive parameter (11) of the first drive component (1) and at least one drive parameter (12) of the second drive component (2) an efficiency of the combination of at least the first drive component (1) and the second drive component (2).

5. Forming machine according to one of the preceding claims, characterized in that the routine (9) is configured to select, for given workpiece parameters (16) and / or bending parameters (17) and / or operating phase (18), those drive parameters (11) of the first drive component (1) and drive parameters (12) of the second drive component (2) where the efficiency of the combination of at least the first drive component (1) and the second drive component (2) and / or the efficiency of the entire drive train (4) is greater than 0.8 and / or has a maximum.

6. Forming machine according to one of the preceding claims, characterized in that the forming machine (5) has at least one sensor (10) for detecting a drive variable, in particular a torque, a pressure, a forming force and / or a position of the first machine part (6) relative to the second machine part (7), and / or at least one sensor (20) for detecting a workpiece property, in particular before and / or during the forming process, wherein the at least one sensor (10, 20) is communicatively connected to the control (8) and the sensor data of the at least one sensor (10, 20) and / or (a) quantity(ies) derived from the sensor data are (a) input quantity(ies) of the routine (9).

7. Forming machine according to one of the preceding claims, characterized in that the forming machine (5) has at least one input interface (19) for inputting workpiece parameters (16) and / or bending parameters (17), wherein the workpiece parameters (16) and / or bending parameters (17) are input variables of the routine (9).

8. Forming machine according to one of the preceding claims, characterized in that the routine (9) is configured to change at least one drive parameter (12) of the second drive component (2) in the course of changing at least one drive parameter (11) of the first drive component (1).

9. Forming machine according to one of the preceding claims, characterized in that the routine (9) is configured to adjust at least one drive parameter (11, 12, 13) of at least one drive component (1, 2, 3) when the efficiency of the combination of at least the first and second drive components (1, 2) is less than a predetermined value and / or falls below a predetermined value during operation of the forming machine (5).

10. Forming machine according to one of the preceding claims, characterized in that the control (8) represents at least two operating phases, in particular a forming phase and a feed phase, which differ in forming force and / or feed speed between the first and second machine part (6, 7), wherein the routine (9) is set up which, depending on the respective operating phase, sets different drive parameters (11) of the first drive component (1) of the drive train. (4) and specify different drive parameters (12) of a second drive component (2) of the drive train (4).

11. Forming machine according to one of the preceding claims, characterized in that the drive train (4) comprises a cylinder-piston unit (14) which can be pressurized by the first drive component (1) and / or second drive component (2).

12. Forming machine according to one of the preceding claims, characterized in that the first drive component (1) and the second drive component (2) are connected in series in the drive train (4).

13. Forming machine according to one of the preceding claims, characterized in that the first drive component (1) comprises a motor, preferably a servo motor, wherein preferably a drive parameter (11) of the first drive component (1) adjustable by the control (8) according to the routine (9) is the speed and / or the torque of the motor.

14. Forming machine according to one of the preceding claims, characterized in that the second drive component (2) comprises a pump driven by the motor, in particular a variable displacement pump, wherein preferably a drive parameter (12) of the second drive component (2) adjustable by the control (8) according to the routine (9) is the delivery volume flow rate, and / or that the second drive component (2) comprises a mechanical transmission, wherein preferably a drive parameter (12) of the second drive component (2) adjustable by the control (8) according to the routine (9) is the transmission ratio.

15. Forming machine according to one of the preceding claims, characterized in that the routine is set up in at least one operating mode of the forming machine (5) in the course of increasing the speed of the motor included by the first drive unit (1), to decrease the flow rate of the pump included by the second drive component (2) and / or in the course of decreasing the speed of the motor included by the first drive unit (1), to increase the flow rate of the pump included by the second drive component (2).

16. Forming machine according to one of the preceding claims, characterized in that at least one drive parameter (13) of a third drive component (3) of the drive train (4) is adjustable by the control (8), wherein the at least one drive parameter (13) of the third drive component (3) is specified by the routine (9) in at least one operating mode of the forming machine (5).

17. Forming machine according to one of the preceding claims, characterized in that the third drive component (3) comprises a valve, wherein preferably a drive parameter (13) of the third drive component (3) adjustable by the control (8) according to the routine (9) is the valve position.

18. Forming machine according to one of the preceding claims, characterized in that the first machine part (6) and / or the second machine part (7) comprises a forming tool holder and / or at least one forming tool.

19. Method for operating a forming machine (5) for forming workpieces (15), in particular a bending machine for bending workpieces, especially sheet metal workpieces, wherein the forming machine (5) comprises a first machine part (6), a second machine part (7), a control system (8) and a drive system for moving the first machine part (6) relative to the second machine part (7) and for generating the forming force, wherein the drive system comprising a drive train (4) formed from at least two drive components (1, 2, 3), characterized in that at least one drive parameter (11) of a first drive component (1) of the drive train (4) and at least one drive parameter (12) of a second drive component (2) of the drive train (4) are adjusted by the control (8), wherein a routine (9) for optimizing the energy efficiency and / or the efficiency of the drive system is stored in the control (8) and the at least one drive parameter (11) of the first drive component (1) and the at least one drive parameter (12) of the second drive component (2) are specified by the routine (9) in at least one operating mode of the forming machine (5).

20. Method according to claim 19, characterized in that the forming machine (5) is designed according to one of the preceding claims.