Method and device for determining the quality of a component formed in a forming process

Abstract

Method for determining the quality of a component (30) formed in a forming process, characterized by the following steps: a) Determining property data (40) of a starting edge (31) created at the beginning of the forming process by means of a sensor device (11), wherein the starting edge (31) is detected by the sensor device (11), b) Transferring (41) the property data (40) determined in step a) to a control unit (12), c) Evaluation of the property data (40) transmitted in step b) by the control unit (12) to detect the approach edge (31), d) Comparing the approach edge (31) identified in step c) with a target specification, and e) Determining the quality of the component (30) formed in the forming process by the control unit (12) based on a result of the comparison carried out in step d), wherein an optical contrast of the starting edge (31) to the rest of the formed component (30) is detected during the determination in step a) and / or during the evaluation in step c).

Description

[0001] The present invention relates to a method according to the preamble of claim 1 for determining the quality of a component formed in a forming process. The invention further relates to a device according to the preamble of claim 7 for determining the quality of a component formed in a forming process, comprising a sensor device and a control unit, wherein the sensor device is configured to determine property data of the formed component after the forming process and the control unit is configured to evaluate the property data determined by the sensor device.

[0002] In modern technology, for example in vehicle manufacturing, components are often subjected to forming processes to achieve a specific shape and design. During forming, the component, which may be made of a metal or a malleable plastic, is deliberately subjected to a plastic deformation. One such forming process could be deep drawing.

[0003] Consistent and, in particular, high quality of the components formed during the forming process is crucial for their further processing. For example, faulty forming can lead to defects such as wrinkles and / or cracks in the component, which can disrupt further processing or, in the worst case, even prevent the component from being used at all.

[0004] To ensure that the forming process was carried out as planned and that the component has no or only negligible forming defects, it is known to perform quality checks on the formed component. Quality control can be performed, for example, by a user. However, such manual quality control is time-consuming and therefore often only possible on a sample basis. Automatic quality control devices are also known, in which, for example, acoustic sensors are used to detect forming defects on the finished component. Another possibility for quality control involves applying markings to the component to be formed and detecting changes to these markings after the forming process; see, for example, DE 10 2014 201 273 A1.However, applying the markings requires an additional processing step, resulting in additional time and costs. Further prior art is known from DE 10 2014 214 201 A1, DE 10 2007 060 278 A1 or DE 20 2004 020 886 U1 as well as DE 41 03 166 C2.

[0005] It is therefore an object of the present invention to at least partially overcome the disadvantages described above in a method and a device for determining the quality of a component formed in a forming process. In particular, it is an object of the present invention to provide a method and a device for determining the quality of a component formed in a forming process that enables the determination of the quality of a component formed in a forming process in a simple and cost-effective manner, wherein, in particular, the material flow in the formed component during the forming process is determined.

[0006] The foregoing problem is solved by a method for determining the quality of a component formed in a forming process, comprising the features of independent claim 1, and by a device for determining the quality of a component formed in a forming process, comprising the features of independent claim 7. Further features and details of the invention will become apparent from the dependent claims, the description, and the drawings. Features and details described in connection with the method according to the invention naturally also apply in connection with the device according to the invention, and vice versa, so that the disclosure of the individual aspects of the invention always makes, or can make, reciprocal reference.

[0007] According to a first aspect of the invention, the problem is solved by a method for determining the quality of a component formed in a forming process. A method according to the invention is characterized by the following steps: a) Determining property data of a starting edge created at the beginning of the forming process using a sensor device, b) Transferring the property data determined in step a) to a control unit, c) Evaluation of the property data transmitted in step b) by the control unit to detect the cutting edge, d) Comparing the approach edge identified in step c) with a target specification, and e) Determining the quality of the component formed in the forming process by the control unit based on a result of the comparison carried out in step d).

[0008] In a first step a) of a method according to the invention, property data of a starting edge are determined. A starting edge, often also referred to as a trailing edge, running edge, starting edge, draw-in edge, or marking line, is formed at the point on the component where the first deformation of the component occurs on a forming tool. This occurs particularly at the beginning of the forming process. During the further forming of the component, the position of the starting edge changes due to the material flow occurring during the forming process. In particular, this position of the starting edge in the component after completion of the forming process makes it possible to obtain information about the material flow that occurred during the forming process. The determination of the property data is carried out by a suitable sensor device. Such a sensor device can, for example, preferably be designed for optical detection of the starting edge.Alternatively or additionally, other detection methods, for example using X-rays, ultrasound, or the like, can be employed to determine property data of the cutting edge. Property data within the meaning of the invention can be any information describing the cutting edge, for example, regarding its position, orientation, shape, and / or size. Overall, by using the cutting edge as the basis for quality determination, the application of an additional marking, which represents a further time-consuming and costly processing step, can be avoided. This alone can save time and thus costs when using a method according to the invention to determine the quality of a formed component. When the cutting edge is detected by the sensor device, in particular by sensor cameras, other elements besides the cutting edge itself, such as...Rigid tool edges, whose position does not change during the ongoing production process, can be detected. Potential error influences, such as vibrations, or systematic errors, such as a change in the position of the sensor camera, can be estimated by evaluating the absolute position of such elements in the image. Self-monitoring during series production can also be achieved by evaluating such "rigid" geometric elements.

[0009] In a second step b), the property data determined in step a) are transmitted to a control unit. This transmission can be wired, but preferably wireless. This transmission allows the sensor device and the control unit to be designed separately. The sensor device can thus be compact, making it particularly easy to position it close to the component, for example, directly within a forming tool. The control unit can be a standalone device or integrated into a higher-level control device, particularly one for the entire forming process.

[0010] In the next step c), the transmitted property data is evaluated by the control unit. The goal of this evaluation is to detect the impact edge. The property data acquired by the sensor device in step a) contains information about the impact edge. By evaluating this property data, the control unit can detect the impact edge. In other words, this evaluation at least partially recreates the impact edge as a data set within the control unit. Based on the acquired property data, the evaluation in the control unit thus results in a representation of the impact edge with the corresponding properties.

[0011] This enables a comparison of the identified cutting edge with a target specification in the following step d). Target specifications within the meaning of the invention are values ​​and / or value ranges that the properties of the cutting edge are intended to occupy, achieve, or maintain. The properties assigned to the identified cutting edge in step c) are at least partially compared with target specifications for the respective property. Such a comparison with a target specification can, for example, result in the target being reached, exceeded, and / or not met.

[0012] A result of a comparison performed in step d) is used in the final step e) of a method according to the invention as a basis for determining the quality of the component formed during the forming process. One or more results from comparisons can be used for this determination. Preferably, the target values ​​in step d) are selected such that they allow for a statement regarding the quality of the formed component. As a non-restrictive example, consider the position of the detected edge, which was compared in step d) with a range of values ​​as a target value. In this case, for example, a high or sufficient quality of the component could be determined if the position of the edge lies within the range of values ​​used as the target value.However, if the comparison in step d) reveals that the position of the detected cutting edge lies outside this value range, then, based on this comparison result, a poor or at least reduced quality of the formed component is determined in step e). Such a target specification, which enables the identification of a component with high or at least sufficient quality, can also be referred to, for example, as a good part process window.

[0013] Overall, the quality of a component formed in a forming process can be determined in a particularly simple and cost-effective manner using a method according to the invention. In particular, the use of a starting edge as the basis for quality determination eliminates the need for the costly and time-consuming application of an additional feature. Furthermore, such a starting edge is created at the beginning of the forming process at a specific position on the component, the position of which can change due to the flow of material within the component during the actual forming process. Therefore, determining the position of the starting edge enables a particularly simple determination of the material flow during the forming process, which in turn has a direct influence on the quality of the formed component.

[0014] Furthermore, in a method according to the invention, it may be provided that during the determination in step a) and / or the evaluation in step c), an optical contrast between the initial edge and the rest of the formed component is detected. As already explained above, the initial edge is usually the first area to be deformed during the forming process, in particular, for example, stretched, compressed, or pressed. This usually results in at least a slight discoloration of the material of the initial edge compared to the material of the component surrounding the initial edge. This discoloration usually results in the initial edge exhibiting a contrast when viewed against the surrounding material of the component. Detecting this contrast thus represents a particularly simple way to determine property data of the initial edge and / or to identify the initial edge when evaluating this property data.

[0015] Preferably, a method according to the invention can be designed such that, during the evaluation in step c), the property data of the cutting edge are approximated by a straight line. This is particularly advantageous if the position and / or orientation of the cutting edge has been determined as property data. Such an approximation of the property data by a straight line makes it possible to describe the cutting edge using only a few parameters. This enables particularly simple and fast evaluation and / or, in particular, low demands on the computing power of the control unit.

[0016] In a method according to the invention, it can also be provided that, during the evaluation in step c), an absolute position of the cutting edge relative to the sensor device is determined. For the purposes of the invention, an absolute position is, in particular, an absolute position of the cutting edge in space with respect to the sensor device and, especially, independent of the arrangement of the formed component. Preferably, the arrangement of the component relative to the sensor device is known, for example, by means of fixing and / or guiding the component. In a comparison in step d) and a subsequent determination of the quality in step e) of a method according to the invention, it is particularly advantageous that this determined absolute position of the cutting edge allows immediate conclusions to be drawn about the material flow that occurred during the forming process, since the origin of the cutting edge is also known.Determining the quality of the formed component can therefore be done particularly easily based on an absolute position of the cutting edge relative to the sensor device.

[0017] Alternatively or additionally, a method according to the invention can be designed such that, during the evaluation in step c), a relative position of the cutting edge relative to geometric elements of the component is determined. Such a geometric element of the component can be, for example, an edge, a hole, a kink, a component end, or the like. In this way, the position of the cutting edge can be determined independently of the spatial arrangement of the formed component. In this embodiment as well, a comparison in step d) and a quality determination based thereon in step e) of a method according to the invention can utilize this determined relative position of the cutting edge, together with the also known origin of the cutting edge, to allow immediate conclusions to be drawn about the material flow that occurred during the forming process.Determining the quality of the formed component can therefore be done particularly easily based on the relative position of the cutting edge to geometric elements of the component.

[0018] In a method according to the invention, it is particularly preferred that at least one limit value is used as a target value during the comparison in step d). This limit value can, for example, be a single value and / or a range of values. During the comparison, it can then be determined whether a property of the detected edge exceeds and / or falls below this value, or whether it lies within or outside this range. By using such a limit value as a target value, the comparison in step d) can thus be carried out particularly easily.

[0019] Particularly preferred according to a further development of a method according to the invention is the determination of at least one limit value by simulation and / or by preliminary tests and / or by stored results from steps d) and e). A method according to the invention determines the quality of a formed component. By means of simulation and / or preliminary tests, a limit value for comparing the detected edge during this quality determination can be determined and provided even before the start of production that includes the forming process. In steps d) and e), the detected edge is compared with a target specification, and the quality of the formed component is determined based on this comparison.By determining a limit value, which is used as a target value in step d) of this comparison, using stored results from these steps d) and e), an iterative determination of the limit value and thus, in particular, for example, a self-learning procedure for determining the quality of a formed component can be provided.

[0020] According to a second aspect of the invention, the problem is solved by a device for determining the quality of a component formed in a forming process, comprising a sensor device and a control unit, wherein the sensor device is configured to determine property data of the formed component after the forming process and the control unit is configured to evaluate the property data determined by the sensor device. A device according to the invention is characterized in that the sensor device is configured to determine property data of a nick created during the forming process, and that the control unit is configured to evaluate this property data to detect the nick, to compare the detected nick with a target specification, and to determine the quality of the forming process based on this comparison.

[0021] A leading edge, often also called a trailing edge, is created during a forming process at the point on the component where the first deformation occurs against a forming tool. This happens particularly at the beginning of the forming process. As the component continues to be formed, the position of the leading edge changes due to the material flow. This position of the leading edge on the component after the forming process is complete allows information about the material flow that occurred during the forming process to be obtained. This material flow is a crucial factor for the quality of a component formed during a forming process. Excessive material flow can lead to wrinkling, while insufficient material flow can cause tearing in the component.

[0022] To determine the quality of a component formed in a forming process, a device according to the invention is designed for determining property data of this cutting edge, wherein the device according to the invention includes a suitable sensor device for this purpose. Preferably, the sensor device can be designed, in particular, for determining property data that enables the determination of the position, orientation, and / or orientation of the cutting edge. The property data determined by the sensor device are transmitted to a control unit and evaluated therein. The control unit can be designed as an independent device, but can also be integrated, for example, into a higher-level control device, in particular a control device for the entire forming process. In particular, the control unit is designed to detect the cutting edge through this evaluation.In other words, after evaluation, the cut edge is represented in the control unit, specifically as a data set. Furthermore, the control unit is designed to compare this detected cut edge with a target value. The target value can be, for example, a single value and / or a range of values. The target value is chosen such that the quality of the component can be determined from the result of the comparison. For example, by comparing the position, location, and / or orientation of the detected cut edge with corresponding target values, it is possible to determine the material flow that occurred during the forming process. As explained above, this allows for a direct determination of the quality of the component formed during the forming process.Overall, the quality of a component formed in a forming process can be determined in a particularly simple and cost-effective manner using a device according to the invention. In particular, by using a starting edge as the basis for quality determination, the costly and time-consuming application of an additional feature, which would require a further time-consuming and costly processing step, can be avoided.

[0023] It is particularly preferred that a device according to the invention be configured to carry out a method according to the first aspect of the invention. Thus, a device according to the second aspect of the invention offers the same advantages as those described in detail for a method according to the first aspect of the invention.

[0024] A device according to the invention can also be designed such that the sensor device has at least one of the following sensor elements: - optical camera sensor - Ultrasonic sensor - Laser sensor - X-ray sensor - haptic sensor

[0025] This list is not exhaustive, so that other types of sensor elements can also be used in a sensor device of a device according to the invention, provided this is technically possible and practical. Furthermore, several sensor elements of the same and / or different designs can be used in the sensor device. Overall, the use of at least one suitable sensor element in the sensor device of a device according to the invention ensures that the property data to be determined for the cutting edge can be reliably acquired.

[0026] Furthermore, in a device according to the invention, it can be provided that the sensor device is arranged at least on and / or in one of the following manufacturing sections of a production line of the forming process: - Forming tool - Transport device - Clipboard - Empty station - Outfeed conveyor

[0027] This list is not exhaustive, so that a device according to the invention can also be arranged in other production sections of a production line, insofar as this is technically possible and practical. In particular, it can be provided that the device according to the invention is at least partially integrated into the respective production section of the production line. A production section of the production line specifically designated for quality control can thus be dispensed with. A particularly simple and, in particular, space-saving determination of the quality of a formed component can therefore be provided.

[0028] A device according to the invention can also be designed such that the sensor device is powered by the production section of the production line in which the sensor device is located. The power supply for the sensor device is thus provided directly and locally by the corresponding production section, for example, via a suitable interface. In this way, the sensor device of the device according to the invention can be powered without the need to run additional power lines from outside the production section to the sensor device. This simplifies the integration of a device according to the invention into a production line.

[0029] Furthermore, a device according to the invention can be provided for the transmission of the property data determined by the sensor device to the control unit via wired and / or wireless means. Such transmission allows the control unit to be located remotely from the sensor device. In particular, this facilitates the integration of the control unit into a higher-level control device, especially a control device for the entire forming process. Wireless transmission of the determined property data is particularly preferred. This eliminates the need to lay additional cables for data transmission from outside the production area to the sensor device.This can also simplify the integration of a device according to the invention into a production line.

[0030] Further advantages, features, and details of the invention will become apparent from the following description, in which exemplary embodiments of the invention are described in detail with reference to the drawings. The features mentioned in the claims and in the description can each be essential to the invention individually or in any combination. Elements with the same

[0031] The function or mode of operation is indicated by the same reference symbols. These are shown schematically: Fig. 1 a forming process of a component, Fig. 2 a reshaped component, and Fig. 3 a device according to the invention.

[0032] In Fig. Figure 1 schematically shows two steps of an exemplary forming process for producing a formed component 30. The upper figure shows an initial state, and the lower figure shows a state immediately after the forming of component 30.

[0033] At the beginning of a forming process, the component 30 is already inserted, and in particular clamped, into a forming tool 51, which represents a production section 50 of a production line. A punch 53 of the forming tool 51 then begins to press against the component 30 from below, as shown in the upper illustration. Fig. 1 represented by an arrow. At this beginning of the forming of the component 30, one or more starting edges 31 are also formed, especially at the points where a first deformation of the component takes place.

[0034] After the transformation is complete, as shown in the lower figure of the Fig. 1. A formed component 30 is now present. For this deformation of component 30, a certain material flow is particularly necessary. This material flow is a crucial factor for the quality of a component 30 formed in a forming process. Excessive material flow can lead to wrinkling, while insufficient material flow can cause tears in the component. Another aspect influenced by this material flow is the position, location, and / or orientation of the starting edge 31 in the formed component 30. Fig. 1, especially when comparing the upper and lower figures, it is clearly evident that during the forming of component 30 the position of the starting edge 31 in component 30 has changed.

[0035] Such a component 30, formed in a forming process, is in Fig. Figure 2 shows the starting edge 31, which is highlighted as a dashed line. Geometric elements 32 are also shown, which here are formed, for example, by surfaces of the component 30. The location, position, and / or orientation of the starting edge 31 relative to these geometric elements 32 allows conclusions to be drawn about how the starting edge 31 is shaped, how it relates to the component 30. Fig. 1 described, changed, in particular moved, during the forming process. This allows for the determination of a material flow that occurred during the forming process and, based on this, an assessment of the quality of the formed component 30.

[0036] This will be demonstrated below using the Fig. Figure 3 explains in more detail, showing a device 10 according to the invention, which is designed to carry out a method according to the invention. The device 10 according to the invention particularly includes a sensor device 11, which, as shown, is preferably integrated into a manufacturing section 50, here an intermediate storage area 52. The sensor device 11 is preferably powered directly via the manufacturing section 50. The sensor device 11 has at least one sensor element 20, which here is designed as a camera sensor 21. Alternatively or additionally, the sensor device can also have other sensor elements 20, for example, an ultrasonic sensor, a laser sensor, an X-ray sensor, or a haptic sensor. This sensor element 20 enables the sensor device 11 to determine property data 40 of a leading edge 31 of the formed component 30.For example, the optical contrast between the cutting edge 31 and the rest of the component 30 can be determined by the sensor element 20. Furthermore, the device 10 according to the invention includes a control unit 12. The transmission 41 of the property data 40 between the sensor device 11 and the control unit 12 preferably occurs wirelessly. In the control unit 12, the transmitted property data 40 are evaluated to detect the cutting edge 31. For example, the relative position of the cutting edge 31 to geometric elements 32 of the component can be determined. Determining the absolute position of the cutting edge 31, particularly with respect to the sensor device 20, is also conceivable. During the evaluation in the control unit 12, it may also be possible to approximate the detected cutting edge 31 with a straight line.In particular, this simplifies the subsequent comparison of the detected edge 31 by the control unit 12 with a target specification, especially a limit value. The limit value used can be determined by simulations and / or preliminary tests prior to the production of the component 30. An iterative determination of the limit value using stored results from previous investigations and evaluations of edge 30 is also conceivable. Based on the result of the comparison, the control unit 12 then determines the quality of the formed component 30. As above. Fig.As already performed, the material flow that occurred during the forming process can be deduced from the property data 40 of the starting edge 31, in particular from the determined position of the starting edge 31. This material flow is a crucial factor for the quality of a component 30 formed in a forming process. Excessive material flow can lead to wrinkling, while insufficient material flow can lead to tearing in the component 30. By evaluating and detecting the starting edge 31 using the control unit 12, and especially by comparing it with target specifications, the quality of a formed component 30 can be determined particularly easily and effectively.The use of a starting edge 31 as the basis for this quality determination thus represents a particularly simple way of determining the quality of the formed component 30, since in particular no additional marking is required on the component 30, which would have to be applied to the component 30 in a further, time-consuming and costly processing step. Reference symbol list 10 Device 11 Sensor device 12 Control unit 20 sensor elements 21 camera sensor 22 Energy supply 30 components 31 Edge 32 geometric elements 40 property data 41 Transfer 50 Production stage 51 Forming tool 52 Clipboard 53 stamps

Claims

[1] Method for determining a quality of a component (30) formed in a forming process, characterized by following steps: a) determining property data (40) of a contact edge (31) created at the start of the forming process by means of a sensor device (11), wherein the contact edge (31) is detected by the sensor device (11), b) transmitting (41) the property data (40) determined in step a) to a control unit (12), c) evaluating the property data (40) transmitted in step b) by the control unit (12) to detect the contact edge (31), d) comparing the edge (31) detected in step c) with a target specification, and e) Determining the quality of the component (30) formed in the forming process by the control unit (12) based on a result of the comparison carried out in step d), wherein during the determination in step a) and / or during the evaluation in step c) an optical contrast of the contact edge (31) to the remaining formed component (30) is detected. [2] Method according to claim 1, characterized by that during the evaluation in step c) the property data (40) of the contact edge (31) are approximated by a straight line. [3] Method according to one of the preceding claims, characterized by that during the evaluation in step c) an absolute position of the contact edge (31) relative to the sensor device (11) is determined. [4] Method according to one of the preceding claims, characterized by that during the evaluation in step c) a relative position of the contact edge (31) is determined relative to geometric elements (32) of the component (30). [5] Method according to one of the preceding claims, characterized by that at least one limit value is used as the target value when comparing in step d). [6] Method according to claim 5, characterized by that the at least one limit value is determined by a simulation and / or by preliminary tests and / or by stored results of steps d) and e). [7] Device (10) for determining a quality of a component (30) formed in a forming process, comprising a sensor device (11) and a control unit (12), wherein the sensor device (11) is designed to determine property data (40) on the formed component (30) after the forming process and the control unit (12) is designed to evaluate the property data (40) determined by the sensor device (11), characterized by , that the sensor device (11) is designed to determine property data (40) of a contact edge (31) created during the forming process, and that the control unit (12) is designed to evaluate these property data (40) to detect the edge (31), to compare the detected edge (31) with a target specification and to determine a quality of the forming process based on this comparison, wherein the device (10) is designed to carry out a method according to one of the preceding claims 1 to 6. [8] Device (10) according to claim 7, characterized by that the sensor device (11) has at least one of the following sensor elements (20): - optical camera sensor (21) - Ultrasonic sensor - Laser sensor - X-ray sensor - haptic sensor [9] Device (10) according to one of the preceding claims 7 or 8, characterized bythat the sensor device (11) is arranged at least on and / or in one of the following production sections (50) of a production line of the forming process: - Forming tool (51) - Transport device - Clipboard (52) - Empty station - Outfeed conveyor [10] Device (10) according to claim 9, characterized by that an energy supply (22) of the sensor device (11) is provided by the production section (50) of the production line on and / or in which the sensor device (11) is arranged. [11] Device (10) according to one of the preceding claims 7 to 10, characterized by that a transmission (41) of the property data (40) determined by the sensor device (11) to the control unit (12) takes place in a wired and / or wireless manner.

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