Method for operating a manufacturing plant and manufacturing plant

Abstract

The invention relates to a method (1) for operating a production plant (2), in which, in a forming process (3) which depends on at least one actual value of a setting variable of the production plant (2) influencing the forming process (3), at least one blank (4) is formed from an initial geometry (6) into a target geometry (7) by means of at least one tool (5) of the production plant (2), wherein a value characterizing the target geometry (7) is determined and compared with a threshold value, and at least one target value of the setting variable is determined as a function of the determined value if the determined value deviates from the threshold value by more than a predetermined amount.

Description

[0001] The invention relates to a method for operating a production plant according to patent claim 1. Furthermore, the invention relates to a production plant according to patent claim 10.

[0002] WO 2023 / 041 301 A1 discloses a method for operating a press in which semi-finished products are formed into components, wherein at least one material property of the respective semi-finished product is provided and at least one production parameter is recorded which characterizes a state of the press during the formation of the respective semi-finished product into the respective component.

[0003] It is an object of the invention to provide a method for operating a production plant and a production plant so that the service life of the production plant can be particularly increased.

[0004] This object is achieved according to the invention by a method for operating a production plant having the features of patent claim 1 and by a production plant having the features of patent claim 10. Advantageous embodiments of the invention are the subject of the dependent patent claims and the description.

[0005] A first aspect of the invention relates to a method for operating a manufacturing facility. The manufacturing facility is understood in particular to be a production facility, which can also be referred to as a production device or manufacturing apparatus.

[0006] In the method, in at least one forming process, at least one blank is formed from an initial geometry into a target geometry, in particular one that differs from the initial geometry, by means of at least one tool of the production plant. In other words, the at least one forming process is carried out by means of the production plant, in which process the at least one blank is mechanically acted upon by the tool of the production plant in such a way that the blank is formed from the initial geometry into the target geometry. The forming of the blank is understood in particular to mean a change in shape of the blank from the initial geometry to the target geometry, as a result of which the blank, after forming, in particular has the target geometry, i.e. is shaped, for example, according to the target geometry. The forming takes place, for example, automatically. This means that the forming is carried out in particular automatically by means of the production plant.The initial geometry is understood in particular to be an initial shape of the blank. The target geometry is understood in particular to be a target shape of the blank. By forming the blank from the initial geometry into the target geometry, a component is preferably produced from the blank. The component thus has in particular the target geometry. The component can be an end product, i.e. for example a fully manufactured component, or the component is for example an intermediate product, in particular a station part. Thus, for example, after the blank or component has been formed into the target geometry, at least one further production step can be carried out, which for example comprises trimming, machining and / or further forming of the component. The component is intended, for example, for a motor vehicle.This means that the motor vehicle, for example, particularly in its fully manufactured state, comprises the component or the end product manufactured from the component. For example, the component or end product is designed as a body component for the motor vehicle. Accordingly, the blank is, for example, a sheet metal part. This sheet metal part is thus intended, in particular, for body production. The forming process is, for example, a deep-drawing process. Thus, the production plant is designed, for example, as a deep-drawing plant and / or a press.

[0007] The forming process depends on at least one actual value of a setting variable of the production system that influences the forming process. This means that the setting variable for the forming process is set, in particular specifically, whereby the forming process is carried out by the production system, for example, according to the setting variable. The setting variable, and therefore in particular the actual value of the setting variable, characterizes, for example, a force that is exerted on the blank by the tool for forming the blank, i.e. in particular for forming the blank from the initial geometry into the target geometry, preferably directly. In other words, the tool applies the force to the blank, in particular directly, which results in the forming of the blank from the initial geometry into the target geometry.For example, the force has a first force value if the setting variable, in particular the actual value of the setting variable, has a first setting value. Furthermore, the force has a second force value that differs from the first force value if the setting variable, in particular the actual value of the setting variable, has a second setting value that differs from the first setting value. For example, the force is a ram force.

[0008] The term force is understood to mean, in particular, a process force. In the production system, which is, for example, a press for forming sheet metal and is used for deep drawing or other operations, the said force can be changed, in particular in a targeted manner, in order to influence, for example, the quality of the formed component or station part. This change is carried out in particular by changing the setting variable or by changing the actual value of the setting variable. For example, the press exerts the force on the material to be formed, in particular the blank, by moving a ram. It is crucial, for example, that the force exerted by the ram on the material is sufficiently large so that the sheet metal can be completely formed, for example. Furthermore, the press is equipped with, for example, a drawing cushion.In such a case, for example, at least one displacement cylinder of the production system generates the force during deep drawing, which then leads, for example, to pressure being exerted on the sheet metal located, for example, between the die and the sheet holder. In principle, the press can have a split ram. This is used, for example, in double-action drawing. In this case, the punch and the sheet holder are connected, for example, to the ram. The force that the sheet holder exerts on the material of the blank to be formed can be influenced via the split ram. In addition, the production system can, for example, have at least one spring, in particular a gas spring, which can be used, for example, to generate the aforementioned force.

[0009] In order to be able to particularly increase the service life of the production system, which is designed as a press system, for example, and in particular of the tool, at least one value characterizing the target geometry, which can be referred to as the target value, is determined, for example using an electronic computing device of the production system. This means that the value characterizing the target geometry is determined, for example detected or measured, in particular by means of the electronic computing device. In order to detect the value, at least one sensor device is provided, for example, which records at least one signal characterizing the target geometry, wherein this signal can then be transmitted to the electronic computing device, which determines, for example calculates, the aforementioned value, for example depending on the determined signal.The fact that the value characterizes the target geometry is understood in particular to mean that the stated value describes the target geometry, for example at least one property of the target geometry. Thus, the determined value has, for example, an at least indirect, in particular direct, operative relationship with the target geometry. Accordingly, for example, a first value is determined if the target geometry is a first target geometry. Furthermore, for example, a second value different from the first value is determined if the target geometry is a second target geometry different from the first target geometry, which, for example, has a different shape than the first target geometry. The value can be determined by means of the electronic computing device or manually. Furthermore, the determined value is compared with a threshold value, for example by means of the electronic computing device.In this case, it is determined, for example, in particular by means of the electronic computing device, whether the determined value deviates from the threshold value. If the determined value deviates from the threshold value, the extent of the deviation of the determined value from the threshold value is determined, for example by means of the electronic computing device. The threshold value is stored, for example, in a memory of the production system, in particular the electronic computing device. Thus, in order to compare the determined value with the threshold value, the threshold value can be retrieved from the memory, for example, by the electronic computing device.Furthermore, at least one target value of the setting variable is determined, for example, by means of the electronic computing device, depending on the determined value, for example, calculated if the determined value or target geometry value deviates from the threshold value by more than a predetermined or predefined amount. In other words, the target value of the setting variable is determined, for example, by means of the electronic computing device, if the determined value exceeds or falls below the threshold value, i.e., for example, is less than or greater than the threshold value. The predetermined amount can be greater than zero or 0.The fact that the determination of the target value takes place as a function of the determined value is understood in particular to mean that the determined value is used as an input variable in order to determine, in particular to calculate, the target value of the setting variable as an output variable, in particular as a function of the determined value.

[0010] The invention is based in particular on the following findings and considerations: The production of car body components in press shops is divided into several process steps, for example. First, for example, blanks are cut from a coil on a coil line or a blank cutting line. This creates, for example, stacks of blanks which are temporarily stored, for example, before processing in the press line. For example, the blank is such a blank, i.e. is designed in particular as a blank. In the press line, the blank, which is designed in particular as a flat sheet or cut blank, is then deep-drawn, for example. This creates, for example, the station part. This is followed by further process steps such as trimming or post-forming. After each operation, the geometry of the respective station part can therefore change, in particular the current geometry.The station part from the last completed work operation can also be referred to as a component, especially a finished component. The thin sheets processed in the press shops, which can also be referred to as semi-finished products, exhibit fluctuations in their properties. For example, sheet thickness, lubricant quantity, roughness and / or elastoplastic material properties of the blank fluctuate. Depending on the extent of these fluctuations, it may be necessary to adjust process parameters of a production process, for example the aforementioned forming process, in order to achieve a required quality of the produced components. This means that the quality of the produced components is monitored, for example. Furthermore, adjustments are necessary, for example, to avoid unnecessary strain on the press system.Currently, semi-finished product properties, indirect and direct data on component quality and the associated intermediate products, referred to as station parts, and / or process parameters of the deep-drawing and pressing systems can be recorded and assigned, for example, to the respective blank and component. This assignment is made, for example, via a serial number, also known as a serial number, which is applied to a surface of the material during blank cutting. This data is stored in a database, for example, and is therefore accessible. Further analyses can then be performed based on the data stored in the aforementioned database.

[0011] The previously mentioned force is particularly relevant when it acts on the blank or component at the end of a respective forming operation or the forming process. This can involve forming operations such as deep drawing, trimming or post-forming. An example explained below relates to deep drawing. In mechanical processes or presses that are driven by a servo motor, for example, a so-called ram adjustment must be carried out. This value is derived based on the actual height of the tool. If the ram adjustment corresponds exactly to a tool height, the ram moves downwards with each stroke until the tool is, for example, exactly closed. If a ram adjustment value is greater than the tool height, the tool is, for example, not fully closed with each stroke.This means that the station part or component may not be fully formed, depending on the operation. If the ram adjustment is set lower than the tool height, the press can be elastically deformed with each stroke because the distance between a lower surface of the ram and a surface of the press bed is, for example, smaller than the tool height. These are then, for example, the surfaces that are in contact with the tool. This can result in the final pressure between the die and punch being higher than if the ram adjustment exactly matches the tool height. It can be advantageous if the ram adjustment is set slightly lower than the tool height. This can ensure, for example, that sufficient forming is always achieved even with fluctuating elastoplastic material properties, tribological properties and / or thicknesses of the material to be formed.However, it is advantageous to bear in mind that the aforementioned elastic deformation of the press and the tool can, for example, damage the tool and therefore the press in particular. Similarly, with hydraulic presses, the force that should act after the press has completely closed can be selected and can be referred to, for example, as the ram force. If this force is selected too low, the material to be formed will not be sufficiently formed. If the ram force is selected too high, the entire system of press and tool will undergo unnecessary elastic deformation. This can also lead to damage, as, for example, premature material fatigue can occur. Repairing the press when material fatigue occurs can be very costly. The same applies when slide valves are used.This is a mechanical device that allows the tool to be moved in one direction, although this direction does not correspond to the direction of movement of the ram. Damage can also occur in this case if elastic deformation occurs in tools or presses after they have been fully closed. Such slides can be used in trimming or post-forming operations.

[0012] With conventional processes or conventional production systems, for example, it cannot be guaranteed that no unnecessary elastic deformations will occur on the production system, in particular on the tool, when selecting the process forces, for example by adjusting the setting variable. This means that there is a risk of unnecessarily early material fatigue on parts of presses or tools. Such elastic deformations can generally only be detected using very complex measuring equipment. As a result, these deformations cannot usually be measured and evaluated during series operation of the press system, which means that no corresponding deductions can be made from them during series operation, for example. This means that the aforementioned deformation may not be known, particularly during series operation, and therefore may not be noticed, for example.Furthermore, the actual force acting, especially in the production facility, is usually unknown. In particular, only the current actual value of the setting variable is known. Thus, conventionally, the acting force can only be indirectly deduced from the known setting variable. However, since the force itself is usually unknown, the conventional method does not allow any conclusions to be drawn about the actual loads or deformations.

[0013] In contrast, the aforementioned disadvantages can be avoided by means of the method according to the invention. In particular, by determining the value characterizing the target geometry and comparing this value with the threshold value, the method according to the invention can be used to determine, preferably automatically, whether an unwanted deviation from the target geometry occurs. This deviation indicates in particular that the force, in particular an unknown force, deviates from its ideal value. This means that the force, in particular the current force, may, for example, be too high, which can have a negative effect on the aforementioned material fatigue. Accordingly, if it is determined that the determined value deviates from the threshold value by more than a predetermined amount, the target value of the setting variable can be determined, in particular specifically, preferably automatically, whereby the setting variable can, for example, be adjusted in accordance with the target value.This means that the determined target value can be defined as a new actual value of the setting variable, as a result of which, for example, in a further forming process following the forming process, a further blank to be formed in the further forming process can be formed using the tool of the production system operated according to the determined target value of the setting variable, and in particular from the initial geometry into the target geometry. This makes it possible to protect the production system, in particular the tool, and as a result of this, the service life of the production system, in particular of the tool, can be particularly increased. In particular, wear and tear on the tool can be kept particularly low. Accordingly, the method according to the invention is in particular a method for minimizing process forces in order to extend the service life of the production system, which is for example a press system.

[0014] In order to significantly increase the service life of the production system, a further embodiment provides that the threshold value describes an extreme value of the setting variable, the minimum or maximum of which is required to transform the blank from the initial geometry into the target geometry. In other words, the threshold value corresponds to the target geometry value that occurs when the actual value, in particular the current value, of the setting variable is the extreme value of the setting variable. The extreme value is, for example, a minimum value or a maximum value. The minimum value can also be referred to as a minimum. The maximum value can also be referred to as a maximum.The fact that the extreme value is minimally or maximally required to transform the blank from the initial geometry into the target geometry is understood in particular to mean that the previously mentioned force which the tool exerts on the blank has the force value which is minimally or maximally required to transform the blank from the initial geometry into the target geometry, that is to say to be able to bring about the transformation of the blank from the initial geometry into the target geometry, wherein the setting variable or the actual value of the setting variable is then the value of the setting variable at the setting of which the said force value or the said force value of the force occurs.This means that mechanical loads acting on the tool can be kept particularly low, since, for example, a control system can be implemented in which the blank is always subjected to only the minimum force, for example including additional tolerances.

[0015] In order to be able to particularly increase the service life of the production system, it is provided in a further embodiment that the threshold value is adapted, for example by means of the electronic computing device, depending on at least one piece of information which characterizes at least one property of the blank, in particular the blank to be formed. In other words, the threshold value corresponds to a first threshold value if the information corresponds to a first piece of information, and the threshold value corresponds to a second threshold value if the information corresponds to a second piece of information. The fact that the information characterizes at least one property of the blank is understood in particular to mean that the information describes the at least one property of the blank.The property is, for example, a material property, i.e., the existing material of the blank, or a geometry of the blank, such as a thickness, especially sheet thickness. This allows the threshold value to be automatically adjusted if the properties of the blank, especially the current one, change, allowing the determination of the target value of the setting variable to be automatically adjusted. Thus, the determination of the minimum required force, for example, involves a closed-loop control process in which, for example, an optimizer continuously searches for the minimum required force.

[0016] In order to be able to determine the property particularly advantageously, in particular particularly precisely and / or in a particularly low-effort manner, it is provided, for example, that the information is acquired, in particular automatically, by a sensor device of the production plant. Acquisition is understood in particular to mean detecting the information, i.e., for example, measuring the information. Thus, adjusting the threshold value depending on the information can involve adjusting the threshold value depending on the information acquired by the sensor device.

[0017] In order to particularly increase the service life of the production system, a further embodiment provides that, in a reference forming process, in particular one that differs from the forming process, at least one reference blank is formed by means of the tool from a reference initial geometry into a reference target geometry, in particular one that differs from the reference initial geometry. In other words, the production system carries out the reference forming process. The reference forming process is carried out, for example, before the forming process. The actual value of the setting variable, in particular actually set, in the reference forming process is determined, for example, by means of the electronic computing device.This means that the actual value of the setting variable that has been used or set for forming the reference blank from the reference initial geometry into the reference target geometry is determined and, for example, stored in a memory. Furthermore, the determined actual value of the setting variable is preferably defined as the actual value of the setting variable for the forming process, i.e., in particular in the forming process. In other words, the actual value of the setting variable in the forming process is the actual value of the setting variable determined, in particular previously, in the reference forming process. In other words, the actual value of the setting variable determined in the reference forming process is used as the actual value of the setting variable in the forming process. Alternatively or additionally, it is provided, for example, that the determination of the target value of the setting variable depends on the actual value of the setting variable determined in the reference forming process.In other words, the determined actual value of the setting variable is used as the input variable to determine the target value. By specifying the actual value of the setting variable for the forming process or by determining the target value of the setting variable as a function of the determined actual value of the setting variable, findings obtained from the reference forming process, which in particular relate to the setting variable, can be incorporated into the forming process, preferably automatically, for example into the aforementioned control. This means that, for example, if the force exerted on the blank during the forming process deviates from the force exerted on the reference blank during the reference forming process, this can be determined by comparing the value characterizing the target geometry with the threshold value.

[0018] In a further embodiment, it is provided that, in order to determine the actual value of the setting variable, in particular in the reference forming process, an extreme value of the setting variable is determined which is the minimum or maximum required to transform the reference blank from the reference initial geometry into the reference target geometry. This means that the determined actual value of the setting variable in the reference forming process is, for example, exactly the value of the setting variable, for example plus tolerances, which leads to the force value of the force exerted on the blank which is the minimum or maximum required to transform the reference blank from the reference initial geometry into the reference target geometry, that is to say, in particular, in order to be able to transform the reference blank from the reference initial geometry into the reference target geometry, for example just barely.This means, for example, that the mechanical loads on the tool can be kept particularly low, which can significantly extend its service life.

[0019] In order to significantly increase the service life of the production system, a further embodiment provides for the target value of the setting variable to be determined by simulation, i.e., in particular, using at least one simulation model. In other words, the target value of the setting variable is determined, in particular calculated, by at least one simulation, in particular performed using the electronic computing device. The simulation is, for example, a finite element simulation (FEM).

[0020] In order to be able to particularly increase the service life of the production plant, it is provided in a further embodiment that at least one geometry formed or constructed by means of the tool during the forming of the blank, in particular on a surface of the component, is detected by means of at least one optical detection device of the production plant. In other words, the geometry formed, for example, on the surface is detected by means of the optical detection device. Furthermore, the value characterizing the target geometry is determined as a function of the detected geometry. In other words, the detected geometry is used as an input variable in order to determine, for example calculate, the value characterizing the target geometry, for example by means of the electronic computing device.In this case, the acquired geometry is compared with a reference geometry, particularly using the electronic computing device. Thus, the value characterizing the target geometry characterizes, for example, a deviation of the acquired geometry from the reference geometry. The reference geometry is, for example, a design geometry, which is, for example, a CAD geometry. By capturing the geometry using the optical capturing device, the extent to which the target geometry deviates from a desired geometry can be determined particularly precisely and / or with particularly low effort.

[0021] In a further embodiment, the tool has at least two tool parts that can be moved between a closed position and at least one open position, in particular relative to one another. This means that the tool parts are movable or are moved relative to one another at least between the closed position and the at least one open position. The tool parts are moved from the open position to the closed position to form the blank. In other words, the movement of the tool parts or the tool from the open position to the closed position is accompanied by the forming of the blank. For example, by moving the tool parts or the tool from the open position to the closed position, the aforementioned force is applied to the blank, in particular in order to effect the forming of the blank.

[0022] In order to be able to particularly increase the service life of the production plant, at least one, in particular optical, marking is applied to the blank or to the component, preferably by means of at least one marking device of the production plant, in particular of the tool, when the tool parts are in the closed position. In other words, the blank or the component is provided with the marking when the tool parts are in the closed position. The marking is not applied to the blank or the component when the tool parts are outside the closed position, i.e. not in the closed position. The markings are therefore only applied, for example, when the tool parts are in the closed position. The marking is, for example, an embossing. The marking device is designed, for example, as a stamp, in particular a final pressure stamp.Furthermore, it is provided that the applied marking is detected by means of the optical detection device of the production system and the value characterizing the target geometry is determined as a function of the detected marking. In other words, the detected marking is used as an input variable to determine the value characterizing the target geometry, for example by means of the electronic computing device. Accordingly, the value characterizing the target geometry can be used to determine, for example, the extent to which the marking has been applied to the blank or the component. Because the marking is applied in particular only when the tool parts are in the closed position, it can be concluded from the detection of the marking that the tool parts have actually been moved into the closed position during the forming process.Thus, if the marking is not detected, it can be concluded that the tool parts were not fully moved into the closed position during the forming process, i.e., that the tool parts were, for example, always outside the closed position during the forming process. In order to achieve complete closing, i.e., in particular, the complete movement of the tool parts into the closed position, the target value of the setting variable can be adjusted, in particular automatically, in such a way that, for example, during the subsequent or further forming process, the tool parts are moved, in particular completely, into the closed position.

[0023] In order to be able to particularly increase the service life of the production system, it is preferably provided alternatively or additionally that a distance extending between the tool parts in the closed position is recorded or detected by means of at least one distance sensor device, in particular one designed separately from the optical detection device, and that the value characterizing the target geometry is determined as a function of the recorded distance. In other words, the recorded distance is used as an input variable in order to determine, in particular to calculate, the value characterizing the target geometry, for example by means of the electronic computing device. In ideal operation of the production system, the distance corresponds, for example, to a distance threshold value, which is, for example, zero or greater than zero.If the operation of the production plant deviates from ideal operation, the detected distance differs from the distance threshold, for example, i.e., it is greater than zero. Therefore, by detecting the distance, especially if the detected distance deviates from the distance threshold, it can be concluded that the tool parts are not being fully closed, for example.

[0024] A second aspect of the invention relates to a manufacturing plant designed to carry out a method according to the first aspect of the invention. This means that the manufacturing plant is configured, in particular specifically, to carry out the method according to the first aspect of the invention. Thus, the method according to the first aspect of the invention is carried out in particular by means of the manufacturing plant according to the second aspect of the invention. Advantages and advantageous embodiments of the first aspect of the invention are to be regarded as advantages and advantageous embodiments of the second aspect of the invention, and vice versa.

[0025] Further features of the invention emerge from the claims, the figures, and the description of the figures. The features and combinations of features mentioned above in the description, as well as the features and combinations of features mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective specified combination, but also in other combinations or on their own.

[0026] The invention will now be explained in more detail using a preferred embodiment and with reference to the drawings. They show: Fig. 1 a schematic representation of a method according to the invention; and Fig. 2 a schematic representation of a production plant according to the invention; and Fig. 3 a schematic representation to illustrate a forming process of a method according to the invention; and Fig. 4 a schematic representation to illustrate a reference forming process of a method according to the invention.

[0027] In the figures, identical or functionally identical elements are provided with the same reference symbols.

[0028] Fig. 1 shows a schematic representation of a method 1 for operating a production plant 2. The method is in Fig. 1 is illustrated in a schematic flow diagram. The production plant 2 is in Fig. 2 is shown in a particularly schematic representation.

[0029] In the method 1, in a, in particular automatic, forming process 3, at least one blank 4 is formed by means of at least one tool 5 of the production plant 2 from an initial geometry 6 into a target geometry 7, in particular different from the initial geometry 6. This is shown in Fig. 3, in which the forming of the blank 4 is shown schematically. By forming the blank 4 from the initial geometry 6 into the target geometry 7, a component 8 is produced from the blank 4, for example, which accordingly has, in particular, the target geometry 7. The forming of the blank 4 is carried out, for example, in a first step 9, as in Fig. 1 is illustrated by way of example. Forming process 3, for example, is a deep drawing operation.

[0030] The production plant 2 preferably carries out several of the forming processes 3, whereby preferably several blanks 4 are formed from the starting geometry 6 into the target geometry 7, whereby in particular several components 8 are produced. Accordingly, the production plant preferably carries out respective forming processes 3, in each of which a respective blank 4 is formed from the respective starting geometry 6 into the respective target geometry 7, whereby in particular the respective component 8 is produced from the respective blank 4.

[0031] The forming process 3 or the respective forming process 3 depends on at least one, in particular respective, actual value of a setting variable of the production system 2 that influences the forming process 3 or the respective forming process 3. Thus, in the respective forming process 3, for example, the respective actual value of the setting variable is set, in particular by means of at least one setting device of the production system 2, whereby the respective blank 4 is formed from the respective initial geometry 6 into the respective target geometry 7, in particular using this actual value. The actual value of the setting variable influences, for example, a force or respective force that the tool 5 exerts on the blank 4 or the respective blank 4 for forming the blank 4 or the respective blank 4 from the initial geometry 6 into the target geometry 7.Thus, the force, in particular acting on the blank 4, can be adjusted at least indirectly via the actual value of the setting variable, whereby the actual force value may, for example, be unknown. The force mentioned is, for example, a force that is achieved when the tool 5 reaches the bottom dead center, i.e., in particular, the force exerted on the blank 4 when the bottom dead center is reached. This applies in particular when the production system 2 is designed as a press.

[0032] In order to be able to particularly increase the service life of the production system 2, in particular of the tool 5, a value characterizing the target geometry 7 or the respective target geometry 7 is determined, in particular calculated, for example during the respective forming process 3, in particular by means of at least one electronic computing device 10 of the production system 2. This is carried out, for example, in a second step 11, which takes place in particular after the first step 9. Furthermore, in particular during the respective forming process 3, for example by means of the electronic computing device 10, the determined value is compared with a threshold value. This is carried out, for example, in a third step 12, which takes place after the second step 11.Furthermore, at least one, in particular a respective, target value of the setting variable is determined, in particular calculated, for example by means of the electronic computing device 10, depending on the determined value or the respective determined value, if the determined value or the respective determined value deviates from the threshold value by more than a predetermined amount. This is carried out, for example, in a fourth step 13 following the third step 12.For example, in particular in a fifth step 14 taking place after the fourth step 13, the determined target value or the respective determined target value of the setting variable is set for a next forming process 3 taking place after the, in particular current, forming process 3, whereby in the following forming process 3 the determined target value of the setting variable can be used as the actual value of the setting variable in order to form the blank 4 from the initial geometry 6 into the target geometry 7. In other words, the production system 2 is preferably operated as a function of the determined target value, for example by setting or specifying the determined target value as the new actual value of the setting variable, in particular by means of the electronic computing device.

[0033] The threshold value describes, for example, an extreme value of the setting variable, the extreme value of which is, for example, the minimum or maximum required to transform the blank 4 or the respective blank 4 from the initial geometry 6 into the target geometry 7. The threshold value thus correlates, for example, with a minimum value or a maximum value of the aforementioned force. This is particularly preferably the minimum value of the force, whereby by setting or determining the target value of the setting variable, it can be ensured, for example, that, for example in the subsequent forming process 3, the blank 4 is only subjected to the required minimum force by the tool 5 in order to transform the blank 4 from the initial geometry 6 into the target geometry 7.As a result, mechanical stress on the tool 5 can be kept particularly low, whereby the service life of the production system 2, in particular of the tool 5, can be particularly increased.

[0034] For example, in the method 1, at least one reference forming process 15 is carried out before the forming process 3 or before the forming processes 3, in which a reference blank 16 is formed from a reference starting geometry 17 and a reference target geometry 18 by means of the tool 5 of the production plant 2, whereby, for example, a reference component 19 is produced from the reference blank 16, which accordingly has in particular the reference target geometry 18. This is shown in Fig. 4, in which the reference forming process 15 is shown in a schematic representation. The forming of the reference blank 16 takes place, for example, in a first reference step 20.

[0035] Preferably, during the reference forming process 15, the actual value of the setting variable set in the reference forming process 15 is determined, for example, manually or automatically. By determining the actual value of the setting variable set in the reference forming process 15, conclusions can be drawn about the force that is exerted or has been exerted on the reference blank 16 during the reference forming process for forming the reference blank 16. This determination of the actual value of the setting variable is carried out, for example, in a second reference step 21, which takes place in particular after the first reference step 20.

[0036] Preferably, it is provided that the actual value of the setting variable determined in the reference forming process 15 is set as the actual value of the setting variable for the forming process 3 or the respective forming process 3, whereby the forming process 3 or the respective forming process 3 is carried out in particular with this actual value of the setting variable. The setting of the actual value of the setting variable for the forming process 3 takes place, for example, in a third reference step 22, which takes place in particular after the reference steps 20, 21. Alternatively or additionally, the determination of the target value of the setting variable preferably depends on the actual value of the setting variable determined in the reference forming process 15, whereby the determined actual value of the setting variable can be used, for example, as an input variable.

[0037] Preferably, in particular by means of the electronic computing device 10, in order to determine the actual value of the setting variable, in particular in a reference forming process 15, an extreme value of the setting variable is determined which is minimally or maximally required, and the reference blank 16 is to be formed from the reference starting geometry 17 into the reference target geometry 18, and thereby in particular to produce the reference component 19.Because the extreme value of the setting variable is determined to determine the actual value of the setting variable, the operator of the production plant 2 can be required, for example when a new production process is put into operation or when method 1 is used for the first time in an existing production process, to determine the minimum required process forces, in particular at least indirectly, which are just sufficient to form or produce the reference component 19, that is to say, for example, a respective station part or component, from the reference blank 16.

[0038] Thus, in the reference forming process 15, for example, process forces can be determined, in particular for each production process and system, or at least by determining the actual value of the setting variable, conclusions can be drawn about these process forces, for example about the level of the process forces. These process forces are understood to mean, in particular, the force mentioned above. For example, the point in time at which the respective setting of the respective actual value was made for the first time is also determined. The results are then compiled, for example manually in a table or automatically. In this case, each setting of the process forces that occurs can be displayed only once for each production process and, for example, for each system, and the date and time of the first use of these process forces or set actual values ​​can also be displayed, for example.Based on such information, it can be determined, for example, whether the setting of the process forces leads to an increasingly high level of forces over time, which, for example, act at the bottom dead center of the tool 5. In addition, a change in the process forces and / or a difference, in particular a maximum difference, between the set process forces can be calculated, for example, using the electronic computing device 10. This is achieved, for example, by comparing the set actual values ​​of the setting variables. This can be used to identify particularly interesting operating scenarios of the production system 2.If, for example, the different values ​​of the process forces are particularly large, it may be useful to consider a corresponding production process with a particularly high priority, since in such a case, for example, the probability of discovering optimization potential may be particularly high. Frequent adjustment of the set actual values, and thus in particular frequent adjustment of the process forces, can therefore indicate a particularly high optimization potential. In addition to the table already mentioned, it is alternatively or additionally possible, for example, to use statistical methods and / or machine learning methods, e.g. with the help of trend analyses, to also identify production processes that have optimization potential with regard to minimizing the forces that act, for example, at the aforementioned bottom dead center.This can prevent unnecessary stress on production system 2, which could be a press system, for example. This means that a trend indicating increasing process forces can be detected, for example automatically. This then provides the potential to reduce them again. Specifically, the process forces could be a ram adjustment or a ram force.

[0039] In principle, it is conceivable to measure the process forces using data recording and storage methods. However, this is traditionally particularly complex and, depending on the production facility, not even possible. Therefore, the actual process forces can be determined from the setting value and the deviation from the target geometry.

[0040] For example, in particular during the forming process 3 or during the respective forming process 3, the threshold value is adjusted depending on at least one piece of information that characterizes at least one property of the blank 4 or the respective blank 4. This property is, for example, a material property or a geometric property, such as a sheet thickness. The threshold value is adjusted, for example, by means of the electronic computing device 10. It is particularly preferred that the information be recorded or detected by a sensor device 23 of the production system 2.Thus, whenever influencing factors in the form of the aforementioned properties change significantly, and it can then be assumed, for example, that the previously used process forces are no longer sufficient or are too high, the operating personnel of the production plant 2 can be required to determine the minimum required process forces again and / or based on the aforementioned information. In addition to the sheet thickness, elastoplastic properties of the material of the blank 4, tribological properties in a boundary layer between the sheet surface and the tool surface, as well as state variables such as the surface quality of the tool 5, in particular roughness, can influence the optimal selection of the process forces. Thus, method 1 can be supplemented by taking into account the aforementioned influencing factors, provided they are known.If a sufficient amount of data sets is available for this purpose, an optimal choice of process forces can be automatically suggested based on knowledge of such data sets for the influencing variables. Such a data set includes, for example, a selection of the minimum required process forces for the respective prevailing influencing variables. This can be done, for example, using a model from the field of machine learning. In this case, knowledge of the properties of the material to be processed and / or knowledge of state variables of the production system 2, in particular of the tool 5, is used to determine the optimal setting variable, and thereby in particular at least indirectly, the optimal process forces, for example immediately before processing the material.

[0041] If it can be determined that the ram adjustment in mechanical presses or presses with a servo drive, or the ram force in hydraulic presses, has changed in such a way that this leads to higher forces at the lower pressure point of the press stroke, a warning can be automatically issued, for example, thus providing the potential to reduce the process forces by selecting the appropriate setting, for example, by adjusting the ram adjustment or the ram force. Alternatively or additionally, it is conceivable, for example, to automatically adjust the process forces on the system. This is particularly a predictive approach.

[0042] For example, at least one geometry formed by the tool 5 during the forming of the blank 4 or the respective blank 4 is detected by an optical detection device 24 of the production system 2. The determination or respective determination of the value characterizing the target geometry takes place, for example, as a function of this detected geometry. This makes it possible, for example, to determine particularly precisely the extent to which the formed blank 4, i.e., the target geometry 7, deviates from a desired geometry. The optical detection device 24 is, for example, a camera.

[0043] In particular, when the production plant 2 is designed as a press, the tool 5 has, for example, at least two tool parts which can be moved between a closed position and at least one open position, in particular relative to one another, which tool parts are moved from the open position into the closed position in order to form the blank 4 or the respective blank 4, whereby the blank 4 or the respective blank 4 can be mechanically acted upon by the tool parts, for example by moving the tool parts into the closed position, in order to be able to effect the forming, in particular by the aforementioned exertion of the force. For example, the tool 5 is at bottom dead center when the tool parts are in the closed position. For example, the tool 5 is at top dead center when the tool parts are in the open position.

[0044] For example, the production plant 2, in particular the tool 5, has at least one marking device, by means of which at least one mark is applied to the blank 4 or the respective blank 4 when the tool parts are in the closed position. This application of the mark is preferably omitted when the tool parts are outside the closed position, i.e., for example, in the open position. The applied mark, in particular the respective mark, is preferably detected by means of the optical detection device 24 or by means of a further optical detection device 24 of the production plant 2 that is designed separately from the optical detection device 24. The determination of the value characterizing the target geometry, in particular the respective value, is preferably carried out as a function of the detected mark or the detected respective mark.The marking device is, for example, a final pressure stamp. This final pressure stamp creates the mark in the form of an embossed mark on a surface, in particular the sheet metal surface, of the blank 4, for example, shortly before reaching the bottom dead center, i.e., for example, before reaching the closed position, or while reaching the closed position. This embossed mark can be used as an indicator of complete forming.If the process forces were previously reduced to such an extent that the blank is just barely fully formed, and if, for example, recorded quality parameters of produced components are within a predefined specification, the electronic computing device 10 can, for example, store newly determined values ​​for the target value of the setting variable, i.e., for example, the value for the ram force or ram force adjustment, as ideal values ​​for properties of the material currently being processed, at least one process parameter, and / or the state variables, such as the temperature of the tool 5. The process parameter is, for example, at least one setting variable that can or will be changed to influence the quality of the produced components.The optical detection device 24, which is integrated, for example, into the production process, can monitor the automatic stamping carried out by the final pressure stamp. In this case, it is conceivable, for example, for the production system 2 to reduce the process forces, in particular by varying the setting variable, either independently or after confirmation from the operating personnel, until the produced components, i.e., for example, the respective manufactured component 8, can just be formed, in particular completely. If station parts or components are created that are no longer sufficiently formed, they are, for example, rejected. As a rule, the stamping effected by the final pressure stamp can be weakened when a minimum force required to stamp the component is reached. As a result, for example, the rejection of rejected parts is generally not necessary.

[0045] The optical detection device 24 thus makes it possible, for example, to automatically monitor a stamping of the material of the blank 4 caused during forming in order to, for example, determine at an early stage, in particular at least indirectly, when critical process forces have been reached. In this case, it is conceivable, for example, to use optical methods to measure a depth of the stamping formed during forming, in particular immediately before it is removed from the tool 5 or, for example, during transport to another press or to transport containers. The depth of the stamping can serve as a measure of the stamping of the respective station part or component. In the case of an insufficiently stamped component or station part, this depth is, for example, less than in the case of a fully stamped component.A particularly advantageous feature is that the reduction of process forces allows for automatic reaction when the depth of the imprint is minimally reduced. This can prevent, for example, station parts or components from having to be rejected due to insufficient imprinting. A prerequisite for this is, for example, that the process forces are reduced in small increments to achieve a minimum, resulting in only a very slight reduction in the depth of the respective imprint. This imprinting leads, for example, to components or station parts that can be further processed in subsequent processes.

[0046] Alternatively or additionally, the production system 2 has, for example, at least one distance sensor device 25, which is designed in particular separately from the optical detection device 24 and by means of which, for example, a distance extending between the tool parts in the closed position is detected. The value characterizing the target geometry 7 or the respective value is determined as a function of the distance or the respective distance detected, in particular previously. Thus, it is possible, for example, to measure one or more points by measuring the distance, also referred to as the distance, between the tool parts, in particular between tool surfaces of the tool parts, and a sheet metal surface of the blank 4. In this case, it is particularly important to note that this distance must be measured at every measuring point on both surfaces of the blank to the tool 5 or the respective tool part.For example, only if both measurements lead to the conclusion that there is contact, particularly sufficient contact, between the tool surface and the sheet metal surface of the blank 4 can it be deduced that the tool 5 was closed, particularly at bottom dead center. This approach involves, for example, controlling the process forces.

[0047] For example, it is provided that the target value or the respective target value of the setting variable is determined, in particular calculated, by simulation, for example by means of the electronic computing device 10 or by means of a further electronic computing device 10 designed separately from the electronic computing device 10, which is designed separately, for example, from the production plant 2. For example, it is conceivable to determine the required process forces by means of finite element simulation (FE simulation) in order to derive a meaningful value for subsequent production processes in the production plant 2. In the case of hydraulic presses, for example, it is sufficient to rigidly modulate the tool 5 in a simulation model.However, to determine the ram adjustment for servo presses or mechanical presses, for example, a simulation model is required that can represent the elastoplastic properties of an entire system, in particular comprising the press, tool, and sheet metal. This is because the generation of process forces acting at the lower pressure point can result from the elastic deformation of this entire system and thus cannot be assumed to be rigid in the simulation in this case. In a particularly simple approach, the influencing factors can be selected in the simulation such that the worst-case scenario with regard to the required process forces is realized. This means that the selected forces can still lead to fully formed components or station parts, for example, even with unfavorable values ​​of the influencing factors.In a further development of this approach, it is conceivable, for example, to vary the influencing factors in the simulation, particularly in a targeted manner, to determine the worst-case scenario. Alternatively or additionally, it is conceivable, for example, to determine optimal process forces for measured influencing factors using the simulation. For example, during production operation of production plant 2, the process forces can be automatically adjusted based on simulation results.

[0048] Overall, the examples demonstrate how a method for minimizing process forces can be implemented to extend the service life of press systems. The goal of the proposed method is, in particular, to minimize the elastic deformation of presses and tools, while, for example, avoiding the need for complex measurement technology to record these elastic deformations. For this purpose, an approach is proposed that can be supplemented with measurement data as required. Alternatively or additionally, it can be demonstrated that the process forces can also be selected using simulations, particularly finite element simulations.

[0049] Process 1 was explained using a deep-drawing operation as an example. In principle, this process can also be applied to other operations in a press system or to other production facilities. List of reference symbols 1 procedure 2 production facilities 3 Forming process 4 blank 5 tools 6 Initial geometry 7 Target geometry 8 Component 9 first step 10 electronic computing device 11 second step 12 third step 13 fourth step 14 fifth step 15 Reference forming process 16 Reference blank 17 Reference output geometry 18 Reference target geometry 19 Reference component 20 first reference step 21 second reference step 22 third reference step 23 Sensor device 24 optical detection device 25 Distance sensor device

Claims

[1] Method (1) for operating a production plant (2) in which, in a forming process (3) which depends on at least one actual value of a setting variable of the production plant (2) influencing the forming process (3), at least one blank (4) is formed from an initial geometry (6) into a target geometry (7) by means of at least one tool (5) of the production plant (2), wherein a value characterizing the target geometry (7) is determined and compared with a threshold value and, depending on the determined value, at least one target value of the setting variable is determined if the determined value deviates from the threshold value by more than a predetermined amount. [2] Method (1) according to claim 1, characterized by , that the threshold describes an extreme value of the setting parameter, the extreme value of which is required to be minimal or maximal in order to transform the blank (4) from the initial geometry (6) into the target geometry (7). [3] Method (1) according to claim 1 or 2, characterized by , that the threshold is adjusted depending on at least one piece of information which characterizes at least one property of the blank (4). [4] Method (1) according to claim 3, characterized by , that the information is recorded by means of a sensor device (23) of the manufacturing plant (2). [5] Method (1) according to any one of the preceding claims, characterized by , that in a reference forming process (15) a reference blank (16) is formed from a reference output geometry (17) into a reference target geometry (18) using the tool (5), whereby the actual value of the setting parameter set in the reference forming process (15) is determined and • is set as the actual value of the setting parameter for the forming process (3) and / or • the determination of the target value of the setting variable depends on the actual value of the setting variable determined in the reference forming process (15). [6] Method (1) according to claim 5, characterized by , that to determine the actual value of the setting parameter, an extreme value of the setting parameter is determined, which is required at least or at most to transform the reference blank (16) from the reference output geometry (17) into the reference target geometry (18). [7] Method (1) according to any one of the preceding claims, characterized by , that the target value of the setting parameter is determined by simulation. [8] Method (1) according to any one of the preceding claims, characterized by , that by means of an optical detection device (24) of the manufacturing plant (2) at least one geometry formed by means of the tool (5) during the forming of the blank (4) is detected and the determination of the value characterizing the target geometry (7) is carried out as a function of the detected geometry. [9] Method (1) according to any of the preceding claims, characterized bythat the tool (5) has at least two tool parts movable between a closed position and at least one open position, which are moved from the open position to the closed position to form the blank (4), wherein • at least one marking is applied to the blank (4) by means of a marking device of the production plant (2) when the tool parts are in the closed position, and the application of the marking to the blank (4) is omitted when the tool parts are outside the closed position, wherein the applied marking is detected by means of an optical detection device (24) of the production plant (2) and the determination of the value characterizing the target geometry (7) is carried out as a function of the detected marking, and / or • a distance extending between the tool parts in the closed position is detected by means of a distance sensor device (25) and the value characterizing the target geometry (7) is determined as a function of the detected distance. [10] Manufacturing plant (2) which is configured to carry out a method (1) according to any of the preceding claims.

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