Angle measuring device for a press brake

The invention relates to an angle measuring device for a bending press.

For the production of precisely shaped bending parts, adherence to the bending angle required by the design is of particular importance, so that the angle formed must be determined during or after the bending process, compared with the desired standard angle and, if necessary, another bending process must be carried out. However, this requires additional process steps, since to measure the angle, the press has to be opened so far that the bending part is relieved and that access to the bent angle with angle measuring devices is possible. In particular, such a measurement is always associated with a delay in the workflow.

To reduce the effort involved in checking the angle, it is known from the prior art to integrate the measurement of the angle into the bending process, that is to say that the bent angle can be determined without the intervention of an operator. In this regard, DE 10 2008 038 932 A1, for example, discloses a swivel bending machine in which a light sensor is arranged in the bending tool, which detects the point in time and thus the angle at which light enters the gap when the bending part is relieved, i.e. when the bending beam is swiveled back falls between the bent workpiece and the bending beam. Knowing the swivel angle of the bending beam, the bent angle! inferring.

Another embodiment is known from DE 43 12 565 C2, in which a light source directs a light trail onto the cheeks of the bent workpiece, which light trail is recorded by a camera arranged on the press beam and this recorded image is analyzed by an evaluation device in order to use it the bending angle! to calculate. The light source is in the punch or arranged integrated in the counter tool, so that a light trail can be formed on the sheet metal limb when the tool is moved together. Since the image recording with N2010 / 34800

2nd! must be able to detect the light trail on the sheet metal cheeks, this must be aligned at a corresponding angle to the section of the bent part illuminated by the light trails. When the sheet metal part is pressed into the counter tool, the bending punch will at least partially cover the work area, so that detection by the camera is no longer possible.

From JP 2-280920 A an angle measuring device is known in which an image recording device detects the end face of a bent sheet metal part and determines the bending angle via an image evaluation device. To ensure a high quality of resolution, it is disclosed that the distance between the image capturing device and the face of the value part is determined and the focusing device of the image capturing device is set accordingly to this distance.

When bending longer parts, there is always the risk, due to the forces acting, that the machine bed or the press beam, for example, will deform slightly, so that the bending angle in the middle of the bending part can be different compared to the edge sections. In order to form a correct bending angle, it is therefore not expedient to detect the end faces of the bending part, since this only allows a local snapshot to be formed. The design known from the prior art, according to which an optical detection device is integrated in the bending tool, has the disadvantage, however, that very complex and therefore very expensive tools have to be produced and that the arrangement of the detection device tm tool structurally weakens it, so that there is also the risk of incorrect bending. It is also necessary for this to determine the position of the angle measurement along the bending line before the bending is carried out, since the detection device must be arranged in the desired section. Such a configuration therefore requires a considerable amount of manipulation and thus a delay in the bending process.

The design of a detection device as a camera, which is aimed at an illuminated section of the sheet metal part at an angle, has the disadvantage that a bending punch that moves down and performs the bend restricts the camera's field of view of the workpiece and thus the section that is essential for detecting the bending angle is covered by the punch. Furthermore, since the detection of a light trail on the bending part and the subsequent determination of the angle require a certain minimum angle at which the camera is aimed at the workpiece

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3 must be oriented, there is the risk, especially with long bent parts, that only a section of the bent part can be evaluated with such an angle measuring device.

The devices known from the prior art now have the particular disadvantage that the determination of the bending angle either requires very complex bending tools or that the angle determination is essentially only possible for the edge sections of the bending part.

The object of the invention is to create an angle measuring device in which the bending angle can be determined contactlessly and along the bending line without the need for expensive or complex bending tools. In particular, the angle measuring device according to the invention should be easy to retrofit for existing bending presses.

The object of the invention is achieved by an angle measuring device in which a lighting device with at least one illuminant illuminates a section of the surface of the sheet metal part on at least one side of the working plane, the working plane being determined by the direction of travel of the press beam and by the bending line, as a contact line between the press beam and the sheet metal part is clamped. According to the invention, the optical axis of an optical image acquisition device is arranged in the working plane and, furthermore, the optical axis and the bending line enclose an angle of less than 2 ° in the illuminated section.

This angle, which corresponds to an almost parallel arrangement of the optical axis and the bending line, ensures that every illuminated section along the bending line can be recorded by the image capturing device without the detection area being completely covered by the bending die moving down and performing the bending deformation. When a section of the sheet metal part is illuminated by a light source, the individual rays of the beam incident on the sheet metal part are diffusely reflected due to the given surface roughness of the sheet metal part. For the angle measuring device according to the invention, however, only those reflected rays are relevant or are recorded by the image capturing device, which leave the illuminated section at a very small angle in relation to the bending line, that is, quasi parallel to the bending line, and thus enter the detection area of ​​the image capturing device. This also ensures, in particular, that no direct components of the beam leaving the illuminant.

-4 • »· · ·« · • · · · • · · · I • · · · * can be picked up in a bundle by the air detection device. By positioning the lighting device along the bending line, the angle measuring device according to the invention makes it possible to determine the bending angle at any point without restricting the angle determination by the components involved in the bending process.

In addition to the solution described above for the bending press described, the object of the invention is also achieved in that the optical axis and a normal projection track of the optical axis on the surface of the sheet metal part enclose an angle of less than 2 ° in the illuminated section. In this embodiment, an optical image acquisition device is arranged to the side of the press frame, so that the angle between the optical axis and the bending line has a component parallel to the working plane and a component normal to the working plane. The development ensures that, according to the invention, the image capturing device captures only those radiation components which leave the illuminated section essentially parallel to the sheet metal surface. The image capturing device is arranged in such a way that the angle according to the claims is formed in any case when the desired bending angle is reached. During the bending process, this angle will steadily decrease from an initial angle. With this design, half the bending angle is determined so that, assuming a symmetrical course of the bending, the total bending angle results from twice the angle determined according to this design,

According to the invention, the lighting device is provided with at least one light center! formed, which can be arranged, for example, centrally on the press beam and thus illuminates sections on both sides of the working plane. According to a further development, the lighting device can have at least two lighting means, soft lighting means are arranged on both sides of the working plane, in particular on the press beam. This design has the particular advantage that the two illuminants, for example, can be arranged very easily directly on the press beam and aligned with the section to be illuminated and thus always maintain their position correctly aligned when the press ram is lowered. For example, the lighting means can have a magnetically acting holding device and are therefore very easy to attach to the metallic press beam. This has an advantage in particular for service or configuration tasks and also enables a very simple definition of the position along the bending line at which the angle measurement is to take place.

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Since it is of particular interest, especially for long bent parts, to also detect the bending angle in the central areas of the bending line, a further development is advantageous, according to which the illuminant is arranged to be displaceable in the direction along the bending line. For example, a longitudinal guide can be arranged on the press beam or on the machine frame, on which the lamp is arranged or in which guide rail a guide of the lamp engages. In the course of setting up the machine or during bending monitoring, the light source can now be moved into the position at which the bending angle is to be recorded. The advantage of this further development is that the alignment of the lighting means on the section to be illuminated is reliably maintained, regardless of the arrangement position. This design also enables the measuring position to be adjusted very quickly and easily without the need for complex reconstruction work on the bending press.

To simplify the measurement and in particular with regard to the automation of the measurement, a further development is advantageous, according to which the lighting device has a selectively controllable drive means which is in operative connection with the lighting means. For example, the drive means can be formed by a linear motor which is selectively controlled by a control module, which is preferably arranged in the image evaluation device, in order to move the lighting means to the desired position along the bending line. It is also possible that the drive means is formed, for example, by a revolving cable system, the lighting means being guided in a longitudinal guide and being moved to the desired position by a positioning motor by means of the cable pull.

To simplify the angle measurement and to increase the throughput or with regard to the best possible automation, a further development is also advantageous, according to which a plurality of illuminants are arranged in the direction along the bending line. The lighting means are preferably selectively controlled by a control module of the image evaluation device in order to illuminate a sheet metal section on both sides of the plane of travel. According to a further development, it can be provided that the lighting means are activated cyclically in order to be able to continuously determine the currently bent angle at a plurality of positions along the bending line during the bending process.

Since strong vibrations can occur again and again when the angle measuring device is used as intended, a further development is advantageous, according to which the

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- 6Light means is formed by a semiconductor component. Such semiconductor components are very advantageous with regard to their mechanical resistance, since they can withstand major vibrations without damage due to their structural structure. In contrast to thermal emitters, it is also advantageous that such semiconductor components have less self-heating and can therefore be used in the vicinity of flammable lubricants or Hydraulic oils make lower safety requirements necessary. Another advantage is the significantly higher optical efficiency and the lower energy consumption, with a high luminance at the same time.

According to a further development, the illuminant has a lobe-shaped radiation pattern, which has the advantage that the predominant luminous flux emitted by the illuminant is directed in a radiation lobe onto the section to be illuminated and thus a high luminance is achieved there, which is diffuse in the direction of the image capturing device reflected radiation components is advantageous, since the detected light intensity will be higher. The lighting means can for example have a reflector with focusing optics in order to emit the radiation in a correspondingly club-shaped manner. The club characteristics also ensure that no direct radiation components of the illuminant get in the direction of the detection device. For example, a light-emitting diode can be used as the lighting means, which in one possible embodiment has an opening angle of the radiation characteristic between 45 ° and 65 °.

According to a further development, the lighting means has a directional radiation characteristic with an opening angle smaller than 10 °, which has the advantage that by means of a directional radiation characteristic such as is emitted, for example, by a laser, the portion to be illuminated on the bending part will have a high luminance , because with a directed radiation pattern, the entire luminous flux emitted by the illuminant is directed onto the section to be illuminated.

To increase the luminance in the section to be illuminated or to suppress scattered light, which can optionally reach the image capturing device directly from the light source, a further development is advantageous, according to which the lighting device has a beam shaping device, in particular in order to generate a light pattern in the illuminated section . The luminous pattern can, for example, be a strip with a preferred width, which is oriented normal to or at an angle to the bending line and illuminates the sheet metal part. A line pattern can also be applied

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7 to illuminate discrete sections on the sheet metal part. The beam shaping device can be formed, for example, by a diaphragm or lens system, but prism systems or scanning deflection systems are also possible.

A further development according to which the lighting device is arranged integrated in the press beam or in the punch is also advantageous. This design achieves a very close arrangement of the lighting device on the bending line, which has the advantage that an undesired incidence of light from the lighting device directly on the image capture device can be largely suppressed and that even if the stamp is deeply immersed in the bending tool, a there is good lighting of the sheet metal part in the area of ​​the bending line.

Since the invention provides to detect the bending angle along the bending line and therefore the image capturing device must be well adapted to the respective section to be captured, a further development is advantageous according to which the image capturing device has optics that can be focused and / or have a selectively adjustable focal length. By setting the focal length of the optics, the focal point can be placed exactly on the section to be captured, so that for each section to be captured along the bending line, there is an adapted capture optics; in particular, the image opening angle of the optics is adapted to the capture area using optics that can be adjusted in focal length being. As a result of the selective focusing, the focal point in the detection area can be selected in such a way that the highest possible light intensity is detected. If necessary, the focal point can be varied slightly, with an averaging being carried out by the image evaluation device, in order to thus detect an intensity of the detected reflection that is as delimited as possible and at the same time high. The more clearly the detected reflected radiation is restricted to a narrow section of the detection area, the more precisely a line can be formed from it.

With regard to automation, a further development is advantageous according to which the selectively adjustable optics are connected to an adjusting means of the image evaluation device, since this enables the optics of the image acquisition device to be set automatically and therefore not by the operator. This setting is preferably carried out by a control module of the image evaluation device.

Since, according to the invention, the optical axis of the image capturing device and the bending line in the illuminated section enclose an angle, but this angle is very small, so that an approximately parallel alignment of the optical axis and the

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If the bending line is given, a further development is advantageous, according to which the image capturing device is arranged to be pivotable, in particular is designed to be pivotable by an adjusting means. Since according to the invention only the scattered light of the illuminated section is detected, which scattered light leaves the illuminated section quasi parallel to the sheet metal surface in the direction of the image capturing device, very small angular dimensions occur in the case of illuminated sections that are far away from the image capturing device along the bending line, so that is advantageous if in this case the viewing angle of the image capturing device on the illuminated portion can be changed, in particular can be enlarged. For example, the position of the image capturing device along the plane of travel can be changed by choosing a larger distance between the optical axis and the bending line. In addition, the optical axis can be tilted towards the bending line, so that the viewing angle for distant, illuminated sections is improved - that is, the angle between the optical axis and the bending line is changed. Since the optical axis of the image capturing device is arranged in the plane of movement, this adjustment range will have to be very small in order not to cover the illuminated section by the punch moving down.

Another possibility for preventing direct incidence of light from the light source on the image capturing device is characterized in that a polarization element is arranged in the beam path of the illuminant and in the optics of the image capturing device, the polarization planes of the two polarization elements enclosing an angle greater than 0 °. However, this angle is preferably a right angle or be an approximately right angle, so that those radiation components emanating directly from the light source cannot reliably pass the polarization element of the image capturing device. With this development, part of the light diffusely reflected in the illuminated section is lost for the evaluation, but the evaluation reliability can be increased by simplifying the evaluation, since no undesired scattered light is to be expected.

A further development consists in that an optical image capturing device is arranged on both sides of the working plane. In this way, both bending legs can be detected at the same time and the entire bending angle can be determined.

Since, according to an embodiment according to the invention, the arrangement of the image capturing device must be adapted to the bending angle to be achieved, in particular the

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To arrange the image capturing device in such a way that when the desired bending angle is reached, the angle according to the invention is set between the optical axis and the normal projection track, a further development provides that the image capturing device is arranged on a positioning device, which positioning device is adjustable at least in the direction parallel to the working plane is. Thus, the image capturing device can be moved to the corresponding position before the bending process, for example by moving it along a longitudinal guide, which can be arranged on the machine frame.

For automated production, in particular to simplify the setting, a further development is advantageous, according to which the positioning device is connected to a machine control, since direct and, in particular, automated setting is possible. For example, the positioning device can have a longitudinal guide in which the image capturing device is arranged displaceably, the displacement movement being brought about by a drive means controlled by the machine control.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

They each show in a greatly simplified representation:

1 shows a representation of a bending press with the angle measuring device according to the invention:

2 shows a basic illustration of the determination of the bending angle;

3 a) to c) a further possible embodiment of the angle measuring device according to the invention.

1 shows an angle measuring device according to the invention on a bending press 1, the bending press 1 having a press table 2 with a bending die 3 and a press beam 4 with a punch 5 that is movable relative thereto. The press beam 4 is moved towards the bending die 3 in a travel direction 7 by drive means 6, the punch 5, in particular the working edge of the punch, making contact with a sheet metal part 8 to be formed along the bending line 9. The bending line 9 and the direction of travel 7 span the working plane 10.

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The angle measuring device according to the invention now has a lighting device 12 with a lighting means 13, an optical image acquisition device 14 and a data-technical image evaluation device 15. The three components are preferably data-related or communicatively connected to one another, so that, for example, a control module of the image evaluation device 15 controls the activation of the luminous means 13 of the lighting device 12 and at the same time initiates the image acquisition by the frame acquisition device 14. A user interface 16, in particular an input / output device, is preferably connected to the image evaluation device 15 in order to present the result of the angle detection to the operator of the bending press 1 so that he can continue the bending process until the desired bending angle is reached. For automated bending, the image evaluation device can also be connected directly to the control of the bending press 1 or For example, the image evaluation device 15 can be part of the control of the bending press 1, so that the required bending angle is produced automatically and in particular without any operator action.

According to the invention, a beam 17 is emitted from the lighting means 13 onto a section 18, on at least one side of the working plane 10, of the surface of the sheet metal part 8 to be formed. The luminous means can be formed, for example, by a light-emitting diode which, due to its structural design or due to an existing beam shaping device, emits a beam 17 in the direction of the sheet metal part 8. Since the optical axis 20 of the image capturing device 14 is arranged in the working plane 10 and furthermore approximately parallel to the bending line 9, only those rays of the beam 17 incident on the section 18 are captured by the capture area of ​​the image capturing device 14 which, due to the diffuse reflection in the section 18, are reflected essentially parallel to the sheet metal surface. According to the invention, the optical axis 20 and the bending line 9 in the illuminated section 18 enclose an angle 21 of less than 2 °. This small angular dimension justifies the specification of a quasi-parallel arrangement of the optical axis 20 and the bending line 9. In order to be able to represent the angular relationships, the thickness of the sheet metal part 8 and the arrangement of the image detection device 14, in particular the distance 22 of the optical axis 20 from the bending line 9 and the angle 21 resulting from this arrangement, have been exaggerated. The inventive arrangement of the image capturing device 14 now ensures that it is largely ensured that no direct light from the lighting device 12 reaches the capturing area of ​​the image capturing device 14 and that the image capturing from the 7 presses N2010 / 34800

-11 bar 4 is also not impaired during the bending process and that in particular the detection of the bending angle is possible at any point along the bending line 9 and not only, as known from the prior art, on the end portion of a sheet metal part facing an image recording device.

According to an advantageous development, however, it is also provided that the lighting device 12 is designed in such a way that a section on the sheet metal surface 8 is illuminated on both sides of the working plane 10. For this purpose, for example, a light source can be attached to both sets of the working level; these are preferably arranged on the press beam. With such a design it is also possible to determine the bending angle at two different positions along the bending line at the same time by arranging two lighting means at different positions or activating lighting means arranged at different positions,

According to a development, it is provided that the lighting device 12 is arranged displaceably in the longitudinal direction of the bending line. For this purpose, a guide device 23, for example a toothed rack, is arranged on the press beam 4, in which a drive means 24 of the lighting device 12 engages, the drive means 24 being selectively controlled by a control module of the Bi Id evaluation device 15 in order to move the lighting device to the desired position to move along the bending line and thus also to move the illuminated section accordingly. With this development it is possible at any time during the bending process to record the currently formed bending angle at any section along the bending line without manual measurements being necessary or without the sheet metal part 8 having to be removed from the bending press 1 for measurement . In this regard, it is also advantageous if, according to a further development, the focal length of the image acquisition device 14 can be adjusted adjustably, preferably again by a control module of the image evaluation device 15, so that the operator can make several angle measurements at different positions along the line at any time during the bending process and without additional adjustment effort Bending line 9 can perform.

To adapt the angle 21 between the optical axis 20 and the bending line 9, it can be provided according to a further development that the image capturing device 14 is arranged pivotably, in particular that the distance 22 between the image capturing device 14, in particular the optical axis 20, and the bending line 9 as well as

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The pivoting of the image capturing device in the travel plane 10 is designed to be adjustable. If, for example, an angle is to be recorded at the maximum distant section of the sheet metal part, the large length distance will result in a very small angle 21 between the optical axis 20 and the bending line, which will have a negative effect on the readout accuracy. If, in this case, the image capturing device 14 is removed a little further from the bending line, an angle 21 that is more favorable for image capturing is set, so that more diffusely reflected light is captured again.

FIG. 2 shows an exemplary illustration of the image captured by the image capturing device on a display device 25 of a user interface. For reasons of illustration, both the end face area 26 and the end area 27 spaced therefrom are shown in sharp focus. Due to the focal length setting and focusing of the image capturing device, the focus area of ​​the imaging optics is preferably set on the illuminated section 18, so that in particular the end areas 26, 27 are mostly shown blurred. Due to the quasi parallel arrangement of the optical axis and the bending line 9 according to the invention, only those rays of diffuse reflection are detected by the illuminated section 18 which leave the illuminated section quasi parallel to the sheet metal surface 28 in the direction of the detection area of ​​the image capturing device. In FIG. 2, these diffusely reflected radiation components are shown in a simplified manner by light points 29. Because of the surface roughness that is always present, the point of reflection will be statistically distributed over the illuminated section, so that no clearly straight and sharply delimited reflection is recorded, but essentially a reflection band. The individual reflex tone points are then analyzed by an interpolation method and an interpolation line 30 is generated, for example by averaging the reflex tone points on each cheek of the sheet metal part 8. The angle between the two interpolation straight lines 30 is now the bending angle 31 at the position of the illuminated section 18.

Since, according to a further development, the lighting device is designed to be longitudinally displaceable or that several illuminants are arranged in the longitudinal direction, the currently formed bending angle 31 can now be determined during the bending process at several positions along the sheet metal part and thus by correspondingly pushing down the stamp or by mechanical countermeasures of the bending die or the press table and / or by different control of the drive means of the

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- The bending angle formed is corrected for the press beam and the desired bending angle can thus be produced along the sheet metal part.

3a to 3c show a further embodiment of the angle measuring device according to the invention, in which the optical axis of the image capturing device is arranged essentially parallel to the working plane.

3a shows a side view of the machine frame 11, the viewing direction being arranged in the working plane 10. A lighting device 12 with a lighting means is arranged on the press beam 4 and emits a beam 17 onto the surface 32 of the sheet metal part 8, so that a section on the surface 32 is illuminated. This illuminated section is captured by an image capturing device 14, the optical axis of the image capturing device 14 being arranged essentially parallel to the working plane 10, as will be described in detail in the following figures.

An embodiment is advantageous in which a lighting device 12 and an image capturing device 14 are arranged on both sides of the work level 10, since both flexural legs can thus be captured at the same time and thus the entire flexural angle 31 can be captured. In Fig. 3a it is also shown that the image capturing device 14 must be arranged in such a way that when the desired bending angle 31 is reached, the image capturing device 14 can capture the illuminated section on the surface 32 of the sheet metal part 8, so that the optical axis must be above the sheet metal surface. This alignment is described in more detail in the following figures.

FIG. 3 b shows a view of the sheet metal part 8, the viewing plane lying in the surface 32 of the sheet metal part 8.

In an embodiment with two lighting devices on both sides of the working plane, a section 18 is illuminated on the surface 32 on both legs of the sheet metal part 8. Due to the selected view, Fig. 3b, the bending line 9 together with the normal projection track 33, whereby according to the invention the angle 21 between the optical axis 20 of the image capturing device 14 and the normal projection track 33, the optical axis 20 onto the surface 32 of the sheet metal part, is less than 2 °. To illustrate the relationships, this angle is shown clearly exaggerated in the figure.

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When the bending deformation is achieved, the detection area of ​​the image detection device 14 must be directed towards the illuminated section 18 of the sheet metal surface 32 of the sheet metal part, in particular in order to form the angle according to the invention between the optical axis 20 and the normal projection track 33. For this purpose, the image capturing device 14 is preferably arranged on a positioning device 34, which positioning device is preferably arranged on the machine frame 11. The positioning device 34 will in turn have a drive means which is connected, for example, to the machine control so that the drive means of the positioning device is controlled accordingly and the image capturing device is moved to the corresponding position before the bending deformation is carried out. This is particularly possible in an automated manner, because at this point in time, due to a stored programming or stored work instruction, the bending angle to be trained is already known and thus the adjustment work for positioning the image capture device is relieved of the operator.

3c shows a view parallel to the bending line 9 of the image capturing device 14. In FIG. 3c, two possibilities are shown as to how the image capturing device 14 can be arranged in a positioning device 34, the arrangement in the positioning device not being absolutely necessary since the Image capturing device can optionally be arranged directly on the machine frame.

In one possible embodiment, the image acquisition device 14 is arranged in the positioning device so that it can be displaced parallel to the working plane, and is moved in the positioning device by means of a drive means 35, so that the exit point of the optical axis 20 is moved parallel to the working plane 9.

When bending very small bending angles 31, an arrangement of the image capturing device 14 according to the embodiment shown on the right in the figure can lead to a reduction in the captured, illuminated section, since the image capturing device in particular usually has a rectangular image capturing area. Therefore, a training as shown in Fig. 3c, shown on the left, is advantageous because it allows the largest possible area of ​​the illuminated sheet metal surface to be captured even for very small bending angles. Here, too, the image capturing device 14 is again accommodated displaceably in a positioning device 34 and is preferably displaced along the direction of movement by a drive means 35 so as to adjust the position

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- To be able to adjust the bending angle 31. Preferably, the direction of displacement will be oriented essentially normal to the sheet metal surface.

In order to be able to make the greatest possible use of the detection width of the image capturing device 14, a further development is advantageous, according to which the image capturing device 14, as shown, for example, on the right in FIG is. Thus, the image capturing device can be pivoted about the axis of rotation during the movement parallel to the working plane 9, so that the largest possible capture width is always arranged essentially parallel to the sheet metal surface.

In a further development, it is also possible to successively track the image acquisition device to the moving sheet metal limb as the bending deformation progresses, in order to be able to detect a direct and immediate course of the bending deformation.

Finally, it should be noted that in the differently described embodiments, the same parts are provided with the same reference numerals or the same component designations, it being possible for the disclosures contained in the entire description to be transferred accordingly to the same parts with the same reference numerals or the same component designations. The location details chosen in the description, such as above, below, to the side, etc. based on the figure immediately described and shown and are to be transferred accordingly to the new position in the event of a change in position. Furthermore, individual features or combinations of features from the different exemplary embodiments shown and described can also represent independent, inventive or inventive solutions.

All information on value ranges in the present description should be understood to include any and all sub-areas, e.g. the information 1 to 10 should be understood to include all sub-areas, starting from the lower limit 1 and the upper limit 10 , ie all subranges begin with a lower limit of 1 or greater and end at an upper limit of 10 or less, for example 1 to 1.7, or 3.2 to 8.1 or 5.5 to 10.

The exemplary embodiments show possible design variants of the angle measuring device, whereby it should be noted at this point that the invention is not restricted to the specifically illustrated design variants of the same, but rather also diverse ones

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Combinations of the individual design variants with one another are possible and this possibility of variation is within the ability of the person skilled in the art working in this technical field due to the teaching on technical action through the present invention.

All conceivable design variants that are possible through combinations of individual details of the embodiment variants shown and described are therefore also included in the scope of protection

3 shows a further and possibly independent embodiment of the angle measuring device, the same reference numerals or component designations being used for the same parts as in the previous figures. In order to avoid unnecessary repetition, reference is made to the detailed description in the preceding figures.

Above all, the individual embodiments shown in FIGS. 1 to 3 can form the subject of independent solutions according to the invention. The related tasks and solutions according to the invention can be found in the detailed descriptions of these figures.

For the sake of clarity, it should finally be pointed out that, for a better understanding of the structure of the angle measuring device, it or its components have been shown partially not to scale and / or enlarged and / or reduced.

The task on which the independent inventive solutions are based can be found in the description.

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List of reference symbols

Bending press

Press table

Bending die

Press beam

rubber stamp

Drive means

Direction of travel

Sheet metal part

Bending line

Working level

Machine frame

Lighting device

Bulbs

Optical image capture device

Data technology

Image evaluation device

User interface

Bundle of rays

Illuminated section Opening angle optical axis

angle

distance

Guide device

Drive means

Display device

Face

End area

Sheet metal surface

Point of light

Interpolation line

Bending angle!

surface

Normai projection track

Positioning device

Drive means