DEVICE FOR MEASURING PLATE-SHAPED WORKPIECES, IN PARTICULARLY FLAT GLASS PANELS OR INSULATING GLASS ELEMENTS

Description

[0001] The invention relates to a device for measuring plate- or panel-shaped workpieces, in particular flat glass panes or insulating glass elements.

[0002] Such a device can be integrated as an independent component in a conveying device of a production plant or combined with a processing device, for example a sealing device, a grinding or cutting device or a device for applying a spacer in the manufacture of insulating glass elements.

[0003] In production processes for plate- or panel-shaped workpieces, especially flat glass panes or insulating glass units, it is common practice to measure the dimensions, i.e., the geometry of the outer contour, for documentation purposes or to control conveying or processing operations. These plate- or panel-shaped workpieces can be rectangular, square, or have special shapes. Fig. 5 shows examples of special shapes of flat glass panes or insulating glass elements that can be measured with the measuring device.

[0004] The dimensions are typically determined as coordinates of prominent boundary points of the outer contour in a rectangular coordinate system, where the X-axis or coordinate represents the length of the workpiece parallel to a conveying direction, the Z-axis or coordinate represents the thickness of the workpiece normal or perpendicular to the conveying direction, and the Y-axis or coordinate represents the height of the workpiece normal to both the X- and Z-axes. Measuring the height (Y-axis) and thickness (Z-axis) is generally straightforward, even for large, flat workpieces, because these dimensions are limited by the throughput width and height of the fixture or machining system, respectively. Measuring the length (X-axis), however, becomes difficult when the maximum dimension of the workpiece exceeds the length of the fixture.In these cases, the length is usually measured continuously during a transport or conveying process of the workpiece in the direction of the X-axis.

[0005] From DE 196 41 861 A1, such a device for determining the shape of sheet-shaped objects, in particular insulating glass panes, is known. This device comprises a support structure against which the sheet-shaped object rests, optical sensors, a conveying device for moving the sheet-shaped object and the optical sensors relative to each other, and a device for determining the conveying path as the X-coordinate of the sheet-shaped object in the form of a position sensor for the drive of the conveying device. A plurality of optical sensors are provided, which are aligned in at least one row parallel to the plane of the sheet-shaped object and at an angle to the conveying direction in order to determine a Y-coordinate of the sheet-shaped object. By corresponding the X- and Y-coordinates to each other, the entire outer contour can be determined.

[0006] A disadvantage of measuring the length or X-coordinate of the workpiece in the conveying direction via a displacement sensor of the conveyor drive is that slippage between the conveyor and the workpiece, which occurs when the conveyor decelerates and accelerates, especially when the workpiece rests on conveyor rollers or conveyor belts and is only held by the friction resulting from gravity, inevitably leads to a measurement error in determining the size, position, and coordinates of the workpiece or of key points on the workpiece where certain machining operations are to be performed.

[0007] From EP 3 433 576 B1, an inspection system for the optical inspection of a flat glass pane is known, in which the flat glass pane rests with one lower end face on a conveyor belt and is moved horizontally by the belt with a plane or main surface of the flat glass pane slightly inclined to the side (in the transverse direction) past a stationary optical inspection unit, which detects irregularities (contamination, holes, scratches, edges) on the flat glass pane. In order to unambiguously assign the positions of these irregularities also in the direction parallel to the conveying direction, the respective position of the flat glass pane in the direction parallel to the conveying direction of the conveyor belt is continuously measured by a measuring device. This device has a stationary linear scale and a caliper that moves with the flat glass pane, the relative position of which to the linear scale can be detected by sensors.

[0008] The caliper is slidably mounted on a support profile. It has a stop that is pivotable relative to the caliper about an axis parallel to the plane of the flat glass pane, so that its stop surface can pivot into or away from the plane of the flat glass pane. The caliper is moved along the length scale by the flat glass pane, against whose front face (in the direction of movement) the stop rests when pivoted in the pivoted position. When the caliper reaches a signal transmitter, or when it is detected that the flat glass pane has completely passed the test unit, the stop is pivoted out of the plane of the flat glass pane, so that the caliper no longer moves with the flat glass pane.

[0009] By means of a conveyor belt, the caliper is moved back to its starting position against the direction of travel of the conveyor belt, where the caliper with its stop part in the swung-in state waits for the arrival of the next flat glass disc until its front face in the direction of travel of the conveyor belt hits the stop part, which causes the caliper to move synchronously with the movement of the next flat glass disc along the length scale.

[0010] In the event that the front edge of the flat glass pane, which is located at the front in the direction of movement, is not oriented perpendicular to the direction of movement, but has areas located at different distances at the front in the direction of movement, as is the case, for example, with the... Fig. 5 In the special configurations shown, and / or when the flat glass pane is very long in the direction of movement, the inspection system according to EP 3 433 576 B1 has two measuring devices, each comprising a length scale and an associated caliper. For such special configurations, the measuring devices are arranged offset from each other in the direction of movement of the flat glass pane and in the vertical direction, and the measuring ranges overlap.

[0011] The caliper that first makes contact with its stop during the movement of the flat glass pane detects the movement and thus the pane's coordinates in the direction of travel even before any part of the pane reaches the optical inspection unit. Once the pane has moved far enough that its front edge also makes contact with the stop of the caliper of the downstream length scale, this caliper takes over the detection of the pane's movement coordinates. The stop of the previously active caliper is then disengaged by the pane, and the caliper is moved back against the pane's direction of travel by its own drive mechanism.Once the rear end face of the flat glass pane has passed the caliper, the caliper can be moved from behind using its own drive mechanism so that its front stop rests against the rear end face of the pane. The rear caliper can then resume detecting the pane's movement coordinates. In this way, the movement coordinates of the flat glass pane can be recorded without gaps, even if the pane is so long that its front surface extends beyond the end of the measuring range of the linear scale positioned behind it, before its rear end face has completely passed the optical inspection unit.

[0012] While this device allows the dimension or coordinate in the longitudinal direction to be determined by the caliper independently of drive slippage, the maximum length of the workpieces that can be measured is limited because one of the two calipers must always be in contact with an end face of the workpiece located at the front or rear (in the conveying direction) within the device's range of motion. Furthermore, the contact of the caliper with the rear end face requires active drive of the caliper during the measuring process, which must be synchronized with the workpiece conveying mechanism, resulting in a relatively complex process.

[0013] The object of the invention is to provide a device for measuring plate- or panel-shaped workpieces, in particular flat glass panes or insulating glass elements, with which even very long workpieces, so-called oversized formats, can be measured with high accuracy.

[0014] The invention provides a device for measuring plate- or panel-shaped workpieces, in particular flat glass panes or insulating glass units, with the features of claim 1. Preferred embodiments are specified in the dependent claims.

[0015] The invention relates in particular to a device for measuring plate-shaped workpieces, especially flat glass panes or insulating glass elements, comprising a conveying device for transporting the plate-shaped workpieces in a conveying direction along a transport track or conveying path, a first measuring device and a second measuring device, wherein each of the measuring devices has a driver configured in such a way that it can be selectively coupled to and decoupled from a plate-shaped workpiece, that in the coupled state it can move with it in the conveying direction, and that in the decoupled state it can be actively moved in a direction opposite to the conveying direction, and which is associated with a preferably stationary measuring ruler extending in the conveying direction, such that a position and / or a movement path of the driver in the conveying direction can be detected.wherein the measuring rulers of the first and second measuring devices are arranged such that they detect different areas of the conveying path of the plate-shaped workpiece in the conveying direction, and wherein the drivers of the first and second measuring devices are designed such that they can be coupled to and decoupled from a main surface of the plate-shaped workpiece.

[0016] An advantage of the device according to the invention for measuring plate-shaped workpieces is that the measurement of at least the length or the coordinates in the longitudinal direction (X-direction parallel to the conveying direction) can be carried out with high accuracy and without the influence of slippage, even for very long workpieces whose lengths significantly exceed the size of the device itself. In principle, the invention enables "endless" length measurement without interrupting the transport or conveying process by repeatedly repositioning the drivers of the two or, if necessary, further measuring devices on the main surface of the workpiece.

[0017] By attaching the guides, especially in the form of suction cups, to the main surface of the workpiece, damage and / or contamination of the end faces, which are often sensitive due to the closely spaced corners of the cut edges, is avoided. The main surfaces, on the other hand, can simply be cleaned at the end of a manufacturing process or continuously protected by protective films.

[0018] Preferably, the drivers are designed to interact contactlessly or mechanically with the respective associated measuring ruler in order to detect the position and / or the distance of movement of the respective driver in the conveying direction.

[0019] Preferably, each of the carriers is assigned to a transport device which is designed to guide the movement of the respective carrier in the conveying direction and to actively move the respective carrier in the direction opposite to the conveying direction via a drive.

[0020] Preferably, the drivers are each mounted on a slide that can be moved along a guide of the transport device.

[0021] Preferably, the slide is divided into two sections which can move relative to each other in the conveying direction, wherein the driver is attached to one of the sections, which is also coupled to the measuring ruler, and the other section is coupled to the drive.

[0022] Preferably, the two sections of the slide are coupled to each other via a cylinder that can be switched between a first state in which it rigidly connects the two sections and a second state in which damped relative movement between the two sections is allowed. Preferably, the transport device has a linear drive or a rotary drive, preferably a conveyor belt or a drag chain.

[0023] Preferably, the drivers each have a suction gripper that can be attached to and detached from the main surface of the plate-shaped workpiece.

[0024] Preferably, the conveying device is designed in such a way that the plate-shaped workpiece can be conveyed on the conveying device in a vertical orientation or in an orientation inclined to the vertical.

[0025] Preferably, the conveying device comprises a roller conveyor or a belt conveyor or a combination thereof.

[0026] Preferably, the conveying device has a conveying drive to actively convey the plate-shaped workpiece in the conveying direction.

[0027] Preferably, the device has a further measuring device for detecting a dimension of the plate-shaped workpiece in a direction perpendicular to the conveying direction.

[0028] Preferably, the device for measuring plate-shaped workpieces has a control unit designed to control the coupling and decoupling of the drivers of the first and second measuring devices in such a way that at least one of the drivers is always coupled to the plate-shaped workpiece during its movement, and to determine a cumulative movement distance of this workpiece in the conveying direction based on the detected positions and / or movement distances of the drivers of the first and second measuring devices.

[0029] Preferably, the control device is designed to assign the detection result of the further measuring device to the cumulative movement distance of the workpiece determined via the drivers of the first and second measuring device in order to determine a contour and / or arbitrary areas of the workpiece.

[0030] The invention is described below by way of example using a preferred embodiment with reference to the figures. Fig. 1a shows a schematic perspective front view of a device for measuring plate-shaped workpieces; Fig. 1b shows the schematic front view of the device of Fig. 1a to explain the measurement and operating principle; Fig. 2 shows a schematic front view of a device for measuring plate-shaped workpieces in a modification with a third measuring device; Fig. 3a shows a front view of a device for measuring plate-shaped workpieces in one embodiment; Fig. 3b shows a perspective front view of the device of Fig. 3a ; Fig. 3c shows in isolation the detail of the measuring devices of the apparatus of Fig. 3a und 3b Viewed from behind; Fig. 4 schematically shows the detail of the slide and the driver in the form of a suction cup in a measuring device; Fig. 5 shows examples of special shapes of flat glass panes or insulating glass elements that can be measured with the measuring device.

[0031] The in Fig. 1a , 1b and 2 Schematically illustrated embodiments of a device 1 according to the invention for measuring plate-shaped workpieces W (hereinafter simply referred to as "measuring device"), in particular flat glass panes or insulating glass elements, comprise a conveying device 2 for conveying the plate-shaped workpieces W in a conveying direction R, which is typically parallel to the X-direction of the measurement, along a conveying path.

[0032] The conveying device 2 is designed such that a plate-shaped workpiece W can be conveyed on the conveying device 2 in a vertical orientation or in an orientation inclined a few degrees to the vertical, while the workpiece W rests on the conveying device 2 at its lower side edge and is supported in the upper area against a lateral guide on a frame, usually with rollers or balls to reduce friction, at one of the two opposing main surfaces F, which define the main planes of the workpiece.

[0033] Conveyor 2 can be operated intermittently, but typically operates continuously during the measurement of a workpiece. Continuous operation is generally advantageous to minimize the effects of acceleration and deceleration and to increase throughput.

[0034] The measuring device 1 according to the variant of Figuren 1a and1b further includes a first measuring device 3A and a second measuring device 3B and the variant of Fig. 2 The system comprises a further measuring device 3C, all of which are essentially identical in design and construction and can be operated independently of one another. Each of the measuring devices 3A, 3B, 3C has a driver 4A, 4B, 4C configured such that it can be selectively coupled to and decoupled from a main surface F of the plate-shaped workpiece W, that in the coupled state it can be passively or forcibly moved with the workpiece in the conveying direction R (the direction of the X-axis), and that in the decoupled state it can be actively moved in a direction R' opposite to the conveying direction R, and that it is associated with a measuring ruler 5A, 5B, 5C fixed to the measuring device, which extends in the conveying direction R (the direction of the X-axis), such that a position and / or a movement distance of the driver 4A, 4B, 4C in the conveying direction R (the direction of the X-axis) can be detected.From the recording of the movement on the measuring ruler, the speed of the movement of the respective driver 4A,4B,4C and thus the actual speed of the movement of the workpiece W can also be determined.

[0035] The measuring guides 5A, 5B of the first and second measuring devices 3A, 3B (and, if applicable, the third or any further measuring device 3C) are arranged such that they detect different areas of the conveying path of the plate-shaped workpiece W in the conveying direction R. The measuring guides may, but need not, overlap, provided that the distances or positions of the initial positions of the drivers within the device in the conveying direction are known or determinable.

[0036] At the in Fig. 1a , 1bIn the illustrated measuring device, measuring devices 3A and 3B are arranged on both sides, in the conveying direction, of a further measuring device 12 for detecting a dimension of the plate-shaped workpiece W in a vertical direction Y perpendicular to the conveying direction R. In the illustrated embodiment, this further measuring device 12 is arranged behind a frame and detects the workpiece through a gap 14 between two adjacent frames 10 of the device for supporting the workpiece. The further measuring device 12 can also be arranged on the front of the frame 10. When arranged behind the frame, the front is free for the arrangement of machining equipment.This additional measuring device 12 can, for example, be equipped like the measuring device described in DE 196 41 861 A1 with one or more rows of optical sensors for recording the height dimension of the workpiece, or alternatively with one or more line scan cameras or a laser scanner or another suitable measuring device for determining the height dimension or the coordinates in the vertical direction of the workpiece (in the direction of the Y-axis). The use of a scanner enables the recording of the outer contour of any special-shaped workpieces. These are flat glass elements that deviate from the rectangular shape – examples of such special shapes are shown in [reference missing]. Fig. 5 depicted.

[0037] The additional measuring device 12 can also be combined with an optical inspection unit for the optical detection of further properties of the workpiece (e.g., defects), as described in EP 3 433 576 B1. Furthermore, the additional measuring device 12 can be stationary or movable in the conveying direction R.

[0038] According to the invention, the drivers 4A, 4B, 4C of the measuring devices 3A, 3B, 3C are designed such that they can be selectively coupled to and decoupled from the main surface F of the plate-shaped workpiece W. A particularly preferred embodiment of these drivers is in the form of a vacuum or suction gripper 11, which is known per se (see Fig. 4 The suction gripper can be attached to and detached from the main surface F of the plate-shaped workpiece W by moving its suction cup in the direction of the Z-axis via a drive (not shown), for example, a hydraulic cylinder, and pressing it against the surface F. Since the suction gripper serves only the purpose of measuring the workpiece's movement (described below) and does not actually transport the workpiece, it can be relatively small and only needs to provide sufficient holding force or vacuum to prevent it from shifting relative to the main surface F when attached, due to friction in the drive, a speed difference in the drive, or vibrations. Additionally, a cover can be placed over the suction gripper to prevent it from leaving marks on the main surface.

[0039] The drivers 4A, 4B, 4C are designed to interact with their respective stationary measuring rulers 5A, 5B, 5C, either contactlessly or mechanically, to detect the position and / or the distance of movement of the respective driver 4A, 4B, 4C in the conveying direction R (the direction of the X-axis). Contactless detection of the movement can be achieved, for example, as described in EP 3 433 576 B1, using a magnetic measuring ruler and a sensor coupled to the movement of the driver, which can detect changes in magnetic field strength along the measuring ruler.

[0040] In addition, each driver 4A, 4B, 4C has one (in the Figuren 1a , 1b and 2(only indicated by the dashed lines with regard to its function) transport device 6A, 6B, 6C assigned, which is designed to guide the movement of the respective assigned carrier 4A, 4B, 4C in the conveying direction R and to drive the respective carrier 4A, 4B, 4C in the direction R' opposite to the conveying direction R via its own drive 7A, 7B, 7C (see Fig. 3c The transport device 6A, 6B, 6C can actively move the workpiece to and from a starting position. It can have a linear drive or a recirculating drive in the form of a conveyor belt, belt, or cable carrier. The drive 7A, 7B, 7C is preferably controllable such that it moves the respective carrier 4A, 4B, 4C in the conveying direction R synchronously with the drive of the workpiece W through the conveying device 2, in order to avoid forces acting on the carrier 4A, 4B, 4C in the conveying direction R that could impair its adhesion to the surface F of the workpiece. The synchronous drive of the carrier 4A, 4B, 4C in the conveying direction R by the drive 7A, 7B, 7C of the transport device 6A, 6B, 6C also reduces inertial effects.

[0041] A particularly preferred embodiment is one in which the drive 7A, 7B, 7C of the respective transport device 6A, 6B, 6C is controlled by detecting a leading edge of the workpiece being conveyed, in order to accelerate the driver 4A, 4B, 4C to the speed of the workpiece before it attaches to the workpiece. A corresponding acceleration phase is preferably also performed before the driver of the subsequent measuring device attaches. Alternatively, a coupling can also be provided in the transport device 6A, 6B, 6C, which decouples the drive 7A, 7B, 7C during the movement of the respective driver 4A, 4B, 4C in the conveying direction R, thereby reducing friction.

[0042] As in Fig. 3c As shown schematically, within the respective measuring device 3A, 3B, 3C, each driver 4A, 4B, 4C can be mounted on a slide 8 (8A, 8B, 8C) which is movable along a guide 9 of the transport device 6A, 6B, 6C. The slide 8 is, as shown in Fig. 4 as indicated, preferably divided into two sections 8a1, 8a2, which can move relative to each other at least in the conveying direction R. Each carrier 4A, 4B, 4C is coupled to one of the sections 8a1, 8a2 (8b1, 8b2) of the respective slide 8, 8A (8B), which is also coupled to the measuring ruler 5A, 5B, 5C, and the other section 8a1, 8a2 of the slide 8 is in turn coupled to the transport device 6A, 6B, 6C of the respective slide 8. The two sections 8a1,8a2 of the slide 8 are coupled to each other via a cylinder 13 or a pair of counter-rotating cylinders 13 as shown, which can be switched between a first state in which it rigidly connects the two sections 8a1,8a2 and a second state in which a free or damped relative movement between the two sections 8a1,8a2 is possible (for example during the measurement phase and / or an acceleration phase starting from the initial position).By determining a difference between the speed of the drivers 4A,4B,4C as determined on the measuring ruler 5A,5B,5C and a speed of the conveying device 2, the drive 7A,7B,7C of the respective transport device 6A,6B,6C can be controlled or regulated in such a way that this difference is compensated and the drives run synchronously in order to avoid forces acting on the drivers 4A,4B,4C in the conveying direction R.

[0043] The carriage 8 interacts, for example via a previously described sensor, with the associated measuring ruler 5A, 5B, 5C to determine the distance of movement and / or position along the measuring ruler. The measuring ruler and the transport device can be combined into a single unit to form the measuring device, as shown in Fig. 3c as indicated. In the embodiment of the Fig. 3a,3b are located in Fig. 3c The measuring devices shown in isolation are elements in an area between the frame 10, which acts as a support wall for laterally supporting the workpieces, and the conveying device 2 for supporting the plate-shaped workpieces on their underside.

[0044] The following will be used as an example to illustrate the Fig. 1b a measurement process using the measuring device according to the invention of Fig. 1a described.

[0045] First, a workpiece W to be measured is conveyed on the conveyor 2 in the conveying direction R. After the leading edge VK of the workpiece W in the conveying direction is detected, the drive 7A of the first transport unit 6A of the first measuring unit 3A is activated to accelerate the suction cup 4A to the speed of the workpiece W before it attaches to the workpiece. The first suction cup 4A of the first measuring unit 3A then attaches itself to the main surface of the workpiece W in the starting position S1. From this point, the measurement of the workpiece's transport distance in the X-direction begins using the first measuring guide 5A of the first measuring unit 3A. Position S1 is located at a certain defined distance from the leading edge VK, back in the opposite direction of conveying R.

[0046] To detect the leading edge VK for the purpose of accelerating the first transport device 6A of the first measuring device 3A, a simple optical sensor or a light barrier is sufficient. For right-angled workpieces, a simple optical sensor or a light barrier is also sufficient to detect the leading edge VK for the purpose of contour measurement. For non-right-angled workpieces, the leading edge can also be detected over its entire height (Y-direction) by a scanner 12, as previously described (the scanner 12 is used here to describe the principle).

[0047] Upon detection of the front edge VK or a characteristic measuring point on the workpiece by the scanner 12, the displacement measurement of the movement of the (first) driver 4A (suction cup) of the first measuring device 3A along the first measuring guide 5A / M1 is continued. Since the distance XO between the sensor / scanner 12 at the detection of the front edge VK and the starting position S1 of the first driver 4A on the first measuring guide 5A is known, the conveying path of the workpiece along the first measuring guide in the direction of the X-axis can be precisely determined when the detection of the movement of the first driver 4A, which is coupled to the workpiece, begins.

[0048] During transport, the workpiece and with it the first carrier 4A are moved from position S1 by the distance X1 in the direction of the X-axis, thus transporting the front section of the workpiece beyond the scanner 12.

[0049] Before the first driver 4A reaches the end position S1', or when the front edge VK or a characteristic measuring point on the workpiece is detected by the scanner 12, the drive 7B of the second transport unit 6B of the second measuring unit 3B is activated to accelerate the driver (suction cup) 4B to the speed of the workpiece W before it attaches to the workpiece. Shortly before the first driver 4A reaches the end position S1', the second driver 4B of the second measuring unit 3B is also coupled to the main surface F of the workpiece W in its initial position S2. For a brief moment, both drivers 4A and 4B are thus in contact with the workpiece W. Here, too, the distance of the initial position S2 of the second driver 4B from the scanner 12 or the end position S1' of the first driver 4A is known or can be determined from the subsequent measurement along the measuring guide 5B.

[0050] The first driver 4A is then decoupled from the main surface F of the workpiece. While the second driver 4B remains coupled to the workpiece W during the preferably continuous transport of the workpiece W by the conveyor 2 in the conveying direction R and moves with it along the distance X2 along the second measuring ruler 5B in the direction of the X-axis, the first driver 4A is actively moved back to its starting position S1 by the transport device 6A of the first measuring device 3A in the direction R' opposite to the conveying direction R. The drive speed of the drive 7B of the second transport device 6B of the second measuring device 3B is controlled synchronously with that of the conveyor 2 by comparing the two speeds and compensating for any difference detected.

[0051] Before the second driver 4B reaches its end position S2', the first driver 4A is again coupled to the main surface F of the workpiece in its starting position S1, as described above. For a brief moment, both drivers 4A and 4B are again in contact with the workpiece W.

[0052] After the second driver 4B is decoupled from the main surface F of the workpiece, the process is repeated by actively moving the second driver 4B back to its starting position S2 in the direction R' opposite to the conveying direction R by the transport device 6B of the second measuring device 3B, and by actively moving the first driver 4A back to its starting position S2 via its coupling with the workpiece during its conveying in the conveying direction R, and recording its movement distance on the first measuring ruler 5A in the direction of the X-axis.

[0053] This process may be repeated several times until the rear edge HK of the glass pane is detected by the scanner 12.

[0054] By capturing the front and rear edges of the workpiece and adding the known distances between the starting positions S1, S2 of the drivers 4A, 4B and the scanner 12, and the movement distances X1, X2, etc. measured at the measuring scales 5A, 5B of the measuring devices in the direction of the X-axis of the drivers 4A, 4B, the total length of the workpiece in the X-direction (parallel to the conveying direction R) can be accurately determined in a continuous process. For rectangular workpieces, capturing the height of the workpiece in the Y-direction using the scanner 12 is sufficient, so that, in conjunction with the length in the X-direction, the size of the workpiece and, if necessary, the position of characteristic measuring points on it can be determined. For non-uniform workpieces, the size and shape can be determined by combining the length in the X-direction with the capture of the contour of the front and rear edges and, if necessary, the position of characteristic measuring points on it.The scanner can also accurately record changes in height in the Y direction.

[0055] The measuring device includes a control unit for controlling this measuring process, which is designed to control the coupling and decoupling of the drivers 4A,4B of the first and the second measuring device 3A,3B in such a way that during the movement of the plate-shaped workpiece W at least one of the drivers 4A,4B is always coupled to it, and to determine a cumulative movement distance of the workpiece W in the conveying direction R (in the direction of the X-axis) based on the detected positions and / or movement distances of the drivers 4A,4B of the first and second measuring device 3A,3B and specified or determined initial positions.

[0056] In order to capture the entire outer contour of the workpiece, the control device is further designed to compare the capture result of the additional measuring device 12 (coordinates of measuring points in the Y direction) with the cumulative movement distance of the workpiece W captured via the drivers 4A,4B of the first and second measuring devices 3A,3B. , that is, to assign the coordinates in the direction of the X-axis in order to determine the entire contour of the workpiece.

[0057] The coordinates of the workpiece assigned in this way can be converted to another reference point within a production line, the distance of which from the reference point or origin of the measuring device is known, so that not only can the position of the workpiece within the production line be determined at any time, but further processing operations at other processing stations can also be precisely controlled with reference to the assigned coordinates of the workpiece determined by the measuring device.

[0058] The Fig. 3a und 3b A front view of a more technically detailed embodiment of the device for measuring plate-shaped workpieces. This device includes a frame 10 on which the plate-shaped workpieces are supported during transport in a position slightly inclined relative to the vertical. The individual components of the measuring device described above are also arranged on the frame, with the use of the same reference numerals indicating the similar function and thus eliminating the need for a repeated detailed description of the components. Fig. 3c shows in isolation the detail of the measuring devices 3A,3B of the device of Fig. 3a und 3b Viewed from behind.

[0059] The conveyor device 2 for the workpieces can be, as shown in the illustration in Fig. 1a and 2As indicated, it can be a familiar roller conveyor with one or more driven rollers. However, it can also be, as in Fig. 3a, 3b As indicated, the conveyor could be a belt conveyor, which is also known per se, or a combination of different conveyors. Preferably, the conveying device has its own conveying drive to actively transport the plate-shaped workpiece W in the conveying direction R. A combination of a non-self-driven conveying device for supporting the workpiece on the underside with a drive device in the form of suction cups, which, like the measuring device, engage one of the main surfaces and convey the workpiece, is also conceivable.

[0060] The measuring device according to the invention was developed with reference to the embodiment of Fig. 1a , 1bThe device is described as having two measuring devices whose drivers are alternately coupled to the main surface of the workpiece and which are carried along during its movement in the conveying direction, and whose measuring scales detect the movement of the drivers. However, the device can be described as follows: Fig. 2 As indicated, a third measuring device 3C and, if necessary, further measuring devices of the same type in the conveying direction may be included, which can be coupled to the workpiece alternately in the same manner. In this embodiment, for example, not only can the length of the workpiece be measured once, but the contour or geometry of the workpiece can be prepared for subsequent processing stations and / or the position of the workpiece within a longer production line can be continuously recorded and used to control various processing operations at the respective processing stations.

Claims

1. An apparatus (1) for measuring a plate-shaped workpiece (W), in particular of flat glas plate or isulation glas elements, comprising: a conveying device (2) for conveying the plate-shaped workpiece (W) in a conveying direction (R) along a conveying path; first measuring device (3A) and second measuring device (3B) wherein each of the measuring devices (3A, 3B) has a driver (4A, 4B) which is konfigured such that it is selectively couplable to and decouplable from the plate-shaped workpiece (W), that, in a coupled state, the driver is moveable together with this workpiece in the conveying direction (R), and that, in a decoupled state, the driver is actively movable in a direction (R') opposite to the conveying direction (R), and which is assigned to a stationary / fixed measuring ruler (5A, 5B), which extends in the conveying direction (R) such that a position and / or a movement distance of the driver (4A, 4B) in the conveying direction (R) can be detected, wherein the measuring rulers (5A, 5B) of the first and second measuring devices (3A, 3B) are arranged such that they detect different regions of the conveying path of the plate-shaped workpiece (W) in the conveying direction (R), characterised in that the drivers (4A, 4B) of the first and second measuring devices (3A, 3B) are configured such that they are couplable to a main surface (F) of the plate-shaped workpiece (W) and are decouplable from this.

2. The apparatus (1) for measuring a plate-shaped workpiece (W) according to claim 1, wherein the drivers (4A, 4B) are designed to interact in a contactless or mechanical manner with the measuring ruler (5A, 5B), respectively assigned, to detect the position and / or the movement distance of the respective driver (4A, 4B) in the conveying direction (R).

3. The apparatus (1) for measuring a plate-shaped workpiece (W) according to claim 1 or 2, wherein the drivers (4A, 4B) are respectively assigned to a transport device (6A, 6B) that is designed to guide movement of the respective driver (4A, 4B) in the conveying direction (R) and to actively move the respective driver (4A, 4B) in the direction (R') opposite to the conveying direction (R) via a drive (7).

4. The apparatus (1) for measuring a plate-shaped workpiece (W) according to claim 3, wherein the drivers (4A, 4B) are respectively mounted on a carriage (8A, 8B) that is movable along a guide (9) of the transport device (6A, 6B).

5. The apparatus (1) for measuring a plate-shaped workpiece (W) according to claim 4, wherein the carriage (8A, 8B) is divided into two sections (8a1, 8a2) that can move relative to one another in the conveying direction (R), and wherein the driver (4A, 4B) is attached to one of the sections (8a1, 8a2), that also is coupled to the measuring ruler (5A, 5B), and the other sectionis coupled to the drive (6A, 6B).

6. The apparatus (1) for measuring a plate-shaped workpiece (W) according to claim 5, wherein the two sections (8a1, 8a2) of the carriage are coupled to each other via a cylinder (13) that can be switch-over between a first state in which the cylinder rigidly connects the two sections (8a1, 8a2) to one another, and a second state in which a damped relative movement between the two sections (8a1, 8a2) is made possible.

7. The apparatus (1) for measuring a plate-shaped workpiece (W) according to one of the claims 3 to 6, wherein the transport device (6A, 6B) comprises a linear drive or a rotary drive, preferably a drag belt or a drag chain.

8. The apparatus (1) for measuring a plate-shaped workpiece (W) according to one of the claims 1 to 7, wherein the drivers (4A, 4B) each have a suction gripper (11) that is couplable to the main surface (F) of the plate-shaped workpiece (W) and is decouplable from this.

9. The apparatus (1) for measuring a plate-shaped workpiece (W) according to one of the claims 1 to 8, wherein the conveying device (2) is configured such that the plate-shaped workpiece (W) is enable to be conveyed on the conveying device (2) in a vertical orientation or in an orientation inclined with respect to vertical.

10. The apparatus (1) for measuring a plate-shaped workpiece (W) according to one of the claims 1 to 9, wherein the conveying device (2) comprises a roller conveyor or a belt conveyor or a combination thereof.

11. The apparatus (1) for measuring a plate-shaped workpiece (W) according to one of the claims 1 to 10, wherein the conveying device (2) comprises a conveying drive for actively conveying the plate-shaped workpiece (W) in the conveying direction (R).

12. The apparatus (1) for measuring a plate-shaped workpiece (W) according to one of the claims 1 to 11, wherein the apparatus comprise a further measuring device (12) to detect a dimension of the plate-shaped workpiece (W) in a direction (Y) perpendicular to the conveying direction (R).

13. The apparatus (1) for measuring a plate-shaped workpiece (W) according to one of the claims 1 to 12, comprising a control unit that is configured to control coupling and decoupling of the drivers (4A, 4B) of the first and second measuring devices (3A, 3B) such that, during movement of the plate-shaped workpiece (W), at least one of the drivers (4A, 4B) is always coupled to this, and to determine a cumulative movement distance of this workpiece (W) in the conveying direction (R) based on the detected positions and / or movement distances of the drivers (4A, 4B) of the first and second measuring devices (3A, 3B).

14. The apparatus(1) for measuring a plate-shaped workpiece (W) according to claim 13 in connection with claim 10, wherein the control unit is designed to assign the detection result of the further measuring device (12) to the cumulative movement distance of the plate-shaped workpiece (W) determined by the drivers (4A, 4B) of the first and second measuring devices (3A, 3B) to determine a contour and / or arbitrary regions of the workpiece.