DE19716018A1 - Tool and installation for foil cutting - Google Patents

Abstract

A tool for cutting a foil is characterised by the fact that its cutting element (4) can be set into high-frequency oscillations. The claims for an installation including such a tool, and for methods of its operation and production of a compound structure are summarized below.

Description

The invention relates to a tool according to the preamble of Claim 1. It also relates to an installation according to the preamble of Claim 8.

The production of laminated glasses is known in practice. Here at least two glass panes with a Polyvinylbutural- (PVB) Fo Lie connected together by first separating the glass panes the film is inserted between the panes and the three are over drawn parts to produce a composite first laminated or passed through calendering rollers and then autoclaved the. Since the film inserted between the individual slices over the Edges of the glass panes must be removed before autoclaving NEN of the film protrusion, so that only such a protrusion remains that can not fall on the glass. Because during the autoclave Four processes would melt the PVB film and leave residues on the Leave glass that would be dangerous if removed, to leave unwanted scratches in the laminated glass pane.  

Therefore, in practice, the film protrusion is immediately after the Reconnect the two panes of glass after inserting the film away. In practice, this is done by equipping with blades Constant workers grasp and stretch the film overhang to then with the blade cuts near the edge and along the contour of the glass to execute. This known technique has a number of shortcomings come on. First of all, pulling on the PVB film makes it easy Stretching of the material that continues in the area between the glasses sets and affects the quality of the future network. Furthermore leaves the cut is slow because only within one cut stroke can be processed in about an arm's length. The cutting force varies with increasing distance from the point at which the film is stretched becomes. This induces shear forces, the stress distributions inside the film in the area between the glasses cause the un are desired. Finally, the manual processing takes place within one Production line often becomes a time-critical station because of the work cycle the separation and re-assembly of the glasses is also safe must be placed, if possible under clean room conditions, in addition, care must be taken to ensure that there are no impurities get between the glasses.

These manufacturing processes are of particular importance of laminated glass found in the automotive industry where wind protection but also rear windows, bulletproof glass panes, and in some Aus guides also other vehicle glass panes made of curved glass can be produced as laminated glass using PVB film. Here arise additional problems, because of the sphere (spatial longitudinal and transverse bend) of the windshield, and the corners that are often indented the circumference of the glass pane runs three-dimensionally in space, so that the film cannot be stretched over longer areas, which leads to leads to shorter cutting strokes. In addition, the short cycle times lead in the manufacture of laminated safety glass windscreens, that the pair of discs is not fixed due to the time required for this is clamped, but only rests on a kind of trestle. An inconsistent Trolled pulling on the film can cause the components to slip of the association, which is critical if one is already back cut film edge is pulled into the pane and thus a complete bond in the edge area of the glass no longer allows. Furthermore, there is also the risk that movements of glass or foil  lead to scratches. After all, the short cuts lead to a multitude of small film residues, which is a collection for re-extruding the films Complicate residues and increase the likelihood of contamination.

In practice, a number of six-axis robots are used Execution of various manipulations known. For example robots are known, the polyurethane caterpillars on the surface of Ein pane safety glass or laminated safety glass for motor vehicles Apply to then the caterpillar material for gluing the Use disk with the body of a motor vehicle.

Welding tools with sonotrodes are known from practice enable ultrasonic welding and, starting from an Ultra sound generator, a mechanical resonance unit to vibrate which resonance unit consists of a converter, a booster and there is a sonotrode, the sonotrode with a slide Contact surface especially allows the welding of plastic films. Here the kinetic energy of the sonotrode system is rubbing on the transferred surface to be machined, causing a by melting material-related sealing effect occurs.

The object of the invention is a cutting tool according to the upper Concept of claim 1 or a system according to the preamble of Claim 8 to create a clean and low-stress films Allow pruning.

This task is performed according to the distinctive part of the Claim 1 and claim 8 solved.

The cutting tool according to the invention is vibrating excitable and can be heated by slightly heating the film Make micro-cuts that are high at a sufficiently high frequency Enable feed speeds. Transfer this to the slide forces are extremely low. Local melting of the film also facilitates the cut. The mechanical stress of the Cutting elements is minimal and thus guarantees a long service life and low regrinding requirement.

The cutting tool according to the invention has according to one pulled a blade, which is piezoelectric for the cut Type of a sonotrode is vibratable. The cutting tool then comprises a mechanical resonance unit emitted by an ultrasound generator can be excited to vibrate and a converter unit with a Piezo crystal, a booster unit and a cutting sonotrode. The  Cutting sonotrode preferably has a substantially wedge shape Shape with a grinded or pointed front edge that the cut executes.

Alternatively, it is possible that in the cutting according to the invention also used cutting element that can be excited to vibrate to be trained differently from a blade, for example as to the Schwin excitable cutting wire or in any other way that the low-tension and energy-saving cutting of film, preferably PVB film, enables.

A system according to the invention for separating a film stands on a laminate to be laminated has a means of positioning the composite on which the lower pane of the composite is applied can be placed on the surface facing away from the positioning means then the PVB film is laid out, on which film the second is in turn Disc is placed. In the simplest case, this positioning means exists from a three-point support, but can also be elongated bucks or on abutments adapted to the shape of the composite material. But it is It is also possible to provide specially trained gauges or end stops watch, it is also possible to use measuring devices for the contour equip.

The system according to the invention further comprises a system according to the invention cutting tool that can be excited by a guide medium can be moved along the contour of the composite. With the leader medium is preferably a six-axis industry robot that can follow any contour in the room and one out has a wide span to include the corners of the ver to bypass the federal government from the outside. Alternatively, it is possible to use the agent to position the assembly rotatably and the guide medium accordingly limited in its relocation.

By using the cutting tool according to the invention the film trimming with minimal force transfer to the film achieve, so that the quality of the network is noticeably improved. The Vibration amplitude of the cutting tool is low, but due to the high frequency, high cutting speeds are possible.

By designing the positioning means as the guide means feedable unit it is possible to prepare for the slides cut back outside the plant and after feeding a  Positioning unit at a predeterminable position in the system the film back cut to perform.

The system according to the invention preferably has optical measurement medium to the distance between the cutting tool and the contour of the Determine the network and preferably to a control of the management forward by. These measuring devices are designed, for example, as cameras forms, which measures the distance to the edge of the composite exactly and deviation Determined from a predeterminable tolerance and for a correction the control of the guide means. But it comes as a measuring device lasers or other contacting measuring devices are also considered.

The system according to the invention expediently comprises wipers medium for the cut film and a film container under half of the positioning means.

The use of the cutting tool according to the invention or the Plant according to the invention is very simple: for separating a flat gene film along a predetermined contour in space, preferably in a predeterminable distance to the contour, the invention is first appropriate cutting tool positioned at a starting point of the contour, e.g. B. by means of a robot, and then with separation of Film overhang shifted along the contour. It is preferably the contour is a closed contour, like that of a spherical one curved windshield. But it is also possible to use this contour only to be provided along an edge of an angular composite. In case of sharp corners, additional travels are useful to drive through to bypass from loops to sharp corners. Alternatively, it is possible to use the Relocate composite and the tool essentially in one place leave or only shift in one direction.

The cutting tool according to the invention is preferably carried out by the guide means each rotated so that there is a contour of Ver assumes essentially normal position and thus perpendicular to Foil (which emerges tangentially from the composite) is arranged.

According to an advantageous further development, a step of Detect the distance of the cutting tool to the contour to which a Evaluation step follows, in which when a predetermined one is exceeded Tolerance a correction is triggered provided. This distance measurement is preferably carried out with a camera or other opti ways. It is also possible to actively use this distance measurement to learn a new contour. It is sufficient here that  Manually cut the cutting tool with the camera along the contour move and then this travel distance around the measured Have the distances corrected and the optimal cut determined in this way save away. As soon as a workpiece with the same dimensions or The traversing program can do this with the same contour be retrieved.

The method described is used with preference a process for the production of laminated safety glass windscreens panes in which the inner and outer glass are initially in pairs be bent, then be removed from the bending station and be separated, the film, which is preferably made of polyvinyl butural exists, is arranged in between, to create the network, and then the composite lami to be formed before an autoclaving step is kidneyed and / or calendered, preferably under vacuum, the Cut back the film before calendering and / or laminating is.

This makes it possible to add the PVB film in an economical manner the manufacture of laminated safety glass windscreens or other laminated or non-bent laminated safety glass products continuously feed the glass. Since no grip surfaces (for manual len clamping) more must be provided for processing the film without being removed from a roll on which it is wound to be cut, placed between the pairs of discs and then with the tool according to the invention in the actual Chen film cut previous step are first separated (straight cut). Due to the high cutting speeds the cycle times are hardly affected. Then takes place in the same cut the separation of the film supernatant, one from one Pieces of existing film waste strips are created, which can be easily disposed of can, for example for reextrusion. Since it is not necessary that Workers perform the cut back of the film, it is preferably possible to PVB film, for example by drive rollers in the edge area, automa feed table. The PVB film is not subject to warping, so that also a direct cut from the film roll the quality of the subsequent PVB film obtained from the roll is not affected. It goes without saying that the film material can be pre-stretched. By direct processing From the film it is possible that a large amount is already available  foils pre-cut to the dimensions of the windshield to avoid sections.

The above steps for film cutting in general and for the cutting back of films protruding from a composite can be quickly and with little power with the cutting unit according to the invention execute stuff. They are preferably automated System, in particular with a controlled robot. It is but also possible to implement the tool according to the invention to move or use the steps described by hand.

Further refinements of the invention are as follows Description and the dependent claims.

The invention is described below with reference to the accompanying figures Illustrated embodiments illustrated in more detail.

Fig. 1 is a plan view of a cutting tool according to the invention with a first variant of a cutting sonotrode.

FIG. 2 is a side view of the tool of FIG. 1.

Fig. 3 is a plan view of another embodiment of a cutting sonotrode for the cutting tool from Figs. 1 and 2.

FIG. 4 is a side view of the cutting sonotrode of FIG. 3.

Fig. 5 is a schematic perspective view of an inventive system with a cutting sonotrode according to FIGS . 3 and 4 in use.

FIG. 6 is a schematic illustration of an exemplary embodiment of a system for film cutting under the invention.

Fig. 7 is a flowchart of the process steps in the manufacture of bent laminated safety glass.

FIG. 8 is a flowchart of the process steps in the film cut back on a system according to FIG. 5.

Figs. 1 and 2 show an embodiment of a conditions to oscillations energizable cutting tool in plan view and in a partially sectioned side view. The excitable vibrating cutting tool 1 consists of a converter 2 , a rigid booster 3 and a cutting sonotrode 4th The components converter 2 and booster 3 are known from welding technology and adopted unchanged, so that they need no further explanation here. The converter 2 comprises an excitable piezo crystal. The tool 1 is excited by an ultrasonic generator of known design with an operating frequency of 40 kHz (output power 700 VA) to oscillate. The connection is designated in Fig. 2 with 2a.

The entire tool 1 is excited to oscillate by the connected ultrasound generator, whereby the smallest movements are carried out at a very high frequency. In ultrasonic welding, this kinetic energy is converted into heat by rubbing a friction surface of the welding probe on a substrate to be melted. In contrast to a welding sonotrode, the cutting sonotrode 4 of the cutting tool 1 according to the invention is provided with a sharpened blade, the edge of which bears the reference number 5 . The cutting sonotrode 4 is designed in the manner of a blade and tapers in a wedge shape toward the blade 5 . Two openings 6 are seen in the cutting sonotrode 4 . The cutting sonotrode 4 can be fastened to the booster 3 by means of a screw 7 . If the entire system 1 is set into vibrations, in particular the blade-like cutting edge 5 vibrates, so that at an oscillation frequency of approximately 40 kHz approximately 80,000 cut movements per second are performed by the blade 5 .

In FIGS. 3 and 4 an alternative embodiment of Figure 4 is 'a cutting sonotrode shown, in the rest to form a cutting tool 1' can be like the cutting sonotrode 4 with the booster 3 and the converter 2 is connected. The cutting sonotrode 4 'has a V-shaped blade, which encloses a 90 ° angle, the blade 5 being ground at 30 °. The thickness of the body of the cutting sonotrode 4 'is tapered several times ( FIG. 2), starting from a thickness of approximately 25 mm to initially 15 mm and then 5 mm. The width of the cutting sonotrode is 30 mm, its length is approximately 78 mm ( Fig. 1), the thin area in front of it takes up about 25 mm. The exact dimensions depend on the resonance behavior. The cutting sonotrode consists of a titanium-based alloy, namely TiAI6V4.

Just as with a welding tool, the cutting tool 1 or 1 'is designed and controlled in operation so that a resonance vibration occurs or at least vibration occurs near the resonance range. As a result, the energy yield is particularly favorable.

Referring now to FIGS. 5 and 6, the use of the cutting tool 1 'according to the invention in a system according to the invention for the film cut on an as yet unconnected laminated glass windshield is shown.

1 ′ also denotes a cutting tool, which is composed of converter 2 , booster 3 and cutting sonotrode 4 ′ as explained above with reference to FIGS. 1 to 4. A cable 8 ver binds the contact 2 a, not shown, with a, also not shown, ultrasonic generator. The converter 2 is fastened to a support plate 9 , which forms the end piece of a robot arm denoted by 10 in the extension. Also attached to the plate 9 is a video camera 11 , the function of which will be described later.

The robot 10 , the arm of which carries the cutting tool 1 ', is part of a system for separating a film excess from a laminate to be laminated, which system further comprises means for positioning the composite. Instead of the robot 10 , any other means for guiding the cutting tool 1 ′ can also be provided, for example a rail, laser or program-controlled system. However, the use of robots is preferred, since they can carry out numerous, very different travels without expensive retrofitting due to stored information. The means for positioning the composite are shown in dashed lines in FIG. 5 as support points 12 . However, it is also possible to provide support blocks adapted to the contour of the United bundle instead of the support points 12 or to provide ventilated suction cups or other means on the support that can hold the United bundle. As a rule, however, it is to be expected that the positioning on the positioning means is subject to a tolerance, to which the manufacturing tolerances of the glasses for the composite and the bending tolerances due to deflection due to the weight of the material add.

The composite shown in FIG. 5 consists of a first (inner) glass pane 13 a and a second (outer) glass pane 13 b, between which a thin film 14 approximately 0.76 cm thick made of polyvinyl butural (PVB) is inserted. The glass panes 13 a and 13 b are spherically curved, that is, their edges define a three-dimensional contour in space. It is of course also possible to provide composites with disks 13 , both of which are flat. It is also possible to provide composites in which one pane or both panes consist of tempered glass. However, panes made of other materials are also possible, in particular the materials need not be transparent, and in particular one of the panes itself can form a composite again. In the present exemplary embodiment, the composite is further processed into a windshield for a motor vehicle. Typical slice thicknesses are between 1.5 and 2.5 mm. The PVB film 14 protrudes over all edges of the panes 13 a, 13 b with a surface area, as indicated in FIG. 5. If the composite is now processed unchanged, there is a risk that the relatively thin and flexible film will be folded over and stuck to one of the outer surfaces of the composite, where it can only be removed after extensive inspection by hand using blades or the like, which is undesirable Danger of causing scratches. It is therefore necessary to cut back the film before the actual connection of the composite, in which the film overhang is shortened to a length of 0.3 to 3 cm. Here, the components 13 a, 13 b and 14 of the composite are still loosely together.

For the desired film cut back, the cutting sonotrode 4 'and in particular its blade 5 are guided closely along the edges of the glass panes 13 a, 13 b. Due to the vibrations of the cutting sonotrode 4 'already explained above, the PVB film 14 is cut in the contact area with the blade 5, heating also taking place in the area due to the high oscillation frequency, which melts the PVB film material and results in a quick and low-power cut enables. The cut is made in a variety of very short strokes at a very high frequency, e.g. B. 40 kHz. Other frequencies are also possible. Almost no vibrational forces are transferred to the area of the PVB film 14 , which is located between the glass panes 13 a and 13 b. There is thus no negative influence on the subsequent steps in the manufacture of the composite due to undesirable tensioning of the composite in its edge region. The cut off from the composite PVB strip 14 runs over the top of the cutting sonotrode 4 'and then falls to the ground as a strip, possibly under guidance along the indicated steps. Ideally, the cut of the standing PVB film 14 is made in a continuous cut, so that a single "waste" strip is formed, which can easily be fed to the reextrusion. Alternatively, the cut is preferably made in such a way that a strip is created for each edge, so that a total of only four strips are produced, which are subsequently fed to reextrusion. Preferably, stripping means are also provided on the robot arm 10 , which ensure a defined removal of the separated film strip.

The arranged on the plate 9 video camera 11 is intended for the observation of the edges of the discs 13 a, 13 b. To the camera 11 . Evaluation means connected on the basis of the from the camera 11 taken image the distance from camera 11 and the edges of the disks 13 a, 13 b can be determined and thus also the distance of the cutting sonotrode 4 'from the edge of the composite (the movements of the cutting tool 1 'due to the vibrations are negligible). The evaluation of the image of the camera 11 thus enables, in a particularly advantageous manner, a correction of all deviations (distance, position) in the dimensional accuracy of the positioning of the composite by means of the measured values of the camera 11 . This correction is expediently carried out by on-line linking of the measured values with the control of the robot 10 . Details of the process will be explained below.

It is possible for the sheet rear section, both the composite of the glass plates 13 a, 13 b and the PVB film 14 trode at a Schneidsono passing out 5, as well as arranged on the robot arm 10 cutting sonotrode 5 along the contour of the parts 13 a, 13 b to proceed. The latter possibility is preferred in the described embodiment, for example, because a z. B. 6-axis robot arm is extremely articulated and can therefore be perfectly adapted to a contour in the room. The control of the robot permits rapid movement of the tool 1 ', which enables high cutting speeds of the film 14 (max. 2 m / s, over the entire path approx. 0.6 m / s, with large disks more). Furthermore, z. B. correct a coordinate control of the robot 10 simply by the measured values of the camera 11 , so that the tolerances mentioned in the positioning of the composite are not at the expense of the accuracy of the film cut. The system according to the invention thus also ensures that a minimum distance from the edge of the glass panes 13 a, 13 b to the tool 1 'is maintained, so that the cutting tool 1 ' does not touch the composite and thus the panes or the film in their relative position not affected each other. On the other hand, compliance with a maximum film overhang is also guaranteed. The difference between the maximum and minimum film protrusion can be set to values below 1 mm and even below 0.1 mm, thus exceeding the manufacturing tolerances of many laminated glass panes.

It is possible to design the system according to the invention in such a way that a robot 10 performs the cut back of the film in a cycle in the case of several composites on a corresponding number of positioning means. For example, you could provide the robot 10 with its superstructures between two groups or even between four groups, and in each case alternately or in a certain order provide the cutting of the film overhang in time with the insertion of PVB film between individual glass panes. The high cutting speed of the cutting tool 1 'thus enables a film cut with low costs. Alternatively, it would be possible to load the system according to the invention in a common structural unit with a glass pane separator and a film insertion machine. It is also possible to pull the film off a roll immediately, e.g. B. by a roller assembly grasping the edge of the film 14 , and by further additional cuts of the tool 1 'to provide a clean separation of the film from the PVB film roll.

In the highly automated system 15 shown in FIG. 6, the same parts as in FIG. 5 are designated with the same reference numerals. The robot 10 is arranged approximately centrally along the longer of the two parallel edges which delimit the dash-dotted trapezoid 13 , which indicates the curved glasses of a motor vehicle windshield. The glasses 13 include a dotted PVB film 14 , the over stood over the glass 13 to be cut with the cutting tool 1 '. A positioning unit 16 carries four support points 12 , which can assume different positions to adapt to the size and curvature of the glass. Dashed lines indicate further positioning units 16 ', 16 "which convey the separated glass 13 a, 13 b to the robot 10 or remove the composite 13 after cutting off the film overhang 14. The positioning units can be driverless transport systems controlled by a controller 17 , or conventional transfer stations, alternatively it is possible, as indicated by 12 'or 16', to feed positioning units via rotary tables or the like.

As soon as the positioning unit 16 has assumed a fixed position, the control 17 causes the robot 10 via a connection 17 a to cut back the film, which will be explained in more detail below. For this purpose, the ultrasound generator 8 a first excites the tool 1 'to vibrate via the cable 8 . The camera 11 delivers the observed image to the evaluation unit 11 a via line 11 b, which outputs determined distance values to the control 17 . A data bus connection 18 also allows the controller to load external data or a process controller integrated with a line for the production of laminated glass. In the system 15 shown , the robot 10 is controlled in such a way that it alternately executes the cut back of the film for the positioning unit 16 and 161 .

The operation of the system according to the invention with the inventions The tool according to the invention is now based on a typical method described in more detail below.

The glass panes 13 a and 13 b are curved inner and outer panes made of glass for a windshield for a motor vehicle, which are to be connected to one another using the PVB film 14 . For this purpose, the glass was first cut into a developed shape and the edges ground, if necessary screen printing applied to one of the sides of the glass panes 13 a and 13 b. Then both panes are bent together, possibly with the addition of a release agent, onto a skeleton through-furnace (step S71). It is of course possible that the two glass sheets were subjected to a pressing step during the bending process. After leaving the furnace and checking the shape match, the two glass panes 13 a, 13 b are separated, and the PVB film is inserted between the two glass panes 13 a, 13 b (step S72). This process step is explained in more detail below with reference to FIG. 8.

For the insertion of the film, the inwardly curved glass pane 13 a is placed on the positioning pins 12 from FIGS. 5 and 6 (step S81), and while the upper glass pane 13 b is held up, for example by ventilating suction cups (step S82), one is already Spread approximately the contour matching film 14 on the outside of the inner glass sheet 13 a (step S83). This process takes place in a clean room to ensure that no particles get into the composite from which they can no longer be removed.

The upper glass pane 13 b is then lowered again onto the lower glass pane 13 a covered with PVB (step S84) and, for example against end stops, the panes are aligned with one another and, if not yet done, are arranged on positioning means 12 of the system 15 near the robot 10 ( Step S85).

Now the robot 10 moves the tool 1 'and in particular its cutting edge 5 to a first point close to the contour of the disks 13 a, 13 b (step S86). Here, the tool 1 'is already in operation, so that the tool may find its way through the PVB film. can cut free. With the help of e.g. B. the camera 11 is preferably a precise starting point, for. B. in a corner of the network to which the tool 1 'is then precisely shifted, controlled (step S87). Then the tool 1 'is moved by the robot arm 10 along the edge of the glass panes 13 a, 13 b in rapid feed, the tool still vibrating at high frequency (step S88). In order to get as close as possible to the contour, the flattened tip of the cutting sonotrode 4 'is moved close to the glass. Here, the camera 11 checks that there is no contact between the vibrating cutting sonotrode 4 'and glass 13 a, 13 b, since the material (TiAI6V4) heats up to temperatures of several hundred degrees Celsius within a very short time due to the friction during vibration would. Small tolerances in the positioning of the glass or in the dimensioning of the glass are also compensated for by correction for the measured actual values, in that the camera measures the distance from the edges of the glass panes 13 a, 13 b and then always a correction outputs signal to the control of the robot arm when a tolerance range is left, preferably in the manner of a control loop.

The robot arm 10 moves the cutting tool 1 'with high advance along the edges and with little advance along the corners. Here, as can be seen in Fig. 5, partly acute angles, which are also referred to as indented corners, which can not be processed in a continuous cut at a given distance from the glass. In such cases, the robot arm 10 can first cut the first edge and continue the cutting path tangentially (step S88) and, after performing a reversing loop for repositioning (step S86), continue with the cutting of the transverse glass edge (step S88).

After completion of the complete cut back of the film, the tool 1 'is moved back into a rest position (step S89), and the assembly can be fed to subsequent stations, as will be described in more detail again below with reference to FIG .

The tool according to the invention and the system according to the invention allow processing speeds of the order of 10 to 12 in per minute, which are correspondingly reduced in the case of complicated geometries and can be increased in the case of purely linear cuts. This results in a machining time of less than one minute, including positioning the tool and returning the tool to its rest position, and even less than half a minute in the case of favorable geometries. Thus, the system 15 according to the invention can conveniently easily inte grate in usual cycle times in the manufacture of windshields. Since the preparation of the assembly (separation, insertion of the PVB film, assembly of the glasses) is approximately of the same order of magnitude, it is particularly advisable to provide a robot system 10 with two receptacles 12 for each assembly for the film cut back, the films alternating cut back by the same robot 10 who the. The system according to the invention enables a low-personnel cut back in which the individual steps are largely automated, so that only small sources of contaminants remain in the ultrapure room.

After the film has been cut back (step S72) there are various options available according to which further processing can be done. A first variant is that on the edge of the Composite a hose for generating a backing vacuum in the composite of Is applied by hand, alternatively it is possible to put the composite in one Insert the bag and pump it out (step S73). On the composite that is already connected by the extracted air closes otherwise adhered, laminated and / or calendered (step S74) before proceeding to Pressures from approx. 12 to 15 bar and temperatures around 100 ° Celsius auto is piano (step S75), and inseparable from a unit, in the present In the case of a windshield for a motor vehicle, is assembled. The remaining excess film melts during autoclaving approx. 0.3 to 3 cm to form a bead, but remains because the bead not enough over the thickness of the glass, in the edge area, and will e.g. B. with a razor or the like now without danger, the Affect bond detached (step S76).

Preferably, the contour along which the tool 1 'or the robot arm 10 is to be moved is first stored by means of a learning step. Here, for example, a finished windshield or a model is positioned in the system according to the invention, and the tool 1 'according to the invention is moved along its contour. The robot's coordinate control remembers the travel path, for example in a suitable memory. During the learning step, the edge of the windshield is observed by the camera 1 and the distance is recorded continuously. This data is also stored in the memory. With a simple routine, the ideal contour along which the tool 1 'is determined is determined by the distance traveled from the edges, as determined by the camera 11, and by a predeterminable remaining protrusion of the film would be proceeded if there is an operation. This travel path is saved for future film cuts. The camera 11 can therefore be used for two purposes: first as a correction measuring element during the cut and also, as described above, as a correction unit during the learning step.

However, it is also possible to provide the camera 11 at a different location from that of the robot arm 10 or to provide a plurality of cameras at fixed points which overall observe the complete contour of the assembly in their observation areas. For calibration purposes, it can also be provided that a mark that can be detected by the camera 11 is also provided at the rest position of the tool as a zero position for the robot controller.

The above exemplary embodiment has been illustrated using a conventional PVB film 14 . However, it is also possible to use the tool according to the invention or the system according to the invention and the process steps described in conjunction therewith for other film materials and in particular also in those composites where in addition to the glass panes 13 a, 13 b and the film 14 further Parts can be integrated into the composite, for example heating conductors for heatable windshields, coatings for heating purposes, colored stripes, etc. Because the cut with the tool according to the invention takes place practically without transferring forces to the film or to the composite, it is It is possible to provide other components in the network that are very sensitive, such as foils for holograms, reflective coatings for rear-view mirrors integrated in the windshield, antennas, and in the future also activated anti-theft devices that cannot be accessed without destroying the windshield.

The film cut back was explained above using a composite of two transparent panes, in particular made of glass. It is understood that the invention is also possible for other materials and with a different number of components. For example, a film could also be cut or cut back, e.g. B. held by Adhä sion or rests loosely on a surface. In particular, it would be possible to cut back the film in the above example without the disc 13 b being put down.

It goes without saying that for carrying out the process described, such cutting tools 1 and 1 'come into consideration, which are moved by hand and which, for. B. by means of a movable device on the edge of the glasses 13 a, 13 b, z. B. with the help of roles.

Claims (29)

1. Cutting tool for a film ( 14 ) with a cutting element, characterized in that for the cut, the cutting element ( 4 ; 4 ') can be set in high frequency vibrations. 2. Cutting tool according to claim 1, characterized in that the cutting element is a cutting sonotrode ( 4 ; 4 '), the piezo-electric can be set in vibration. 3. Cutting tool according to claim 2, further comprising a booster ( 3 ) and a converter ( 2 ), wherein the cutting tool ( 1 ; 1 ') can be set in vibration by an ultrasonic generator. 4. Cutting tool according to claim 2 or 3, characterized in that the cutting sonotrode ( 4 ') has a V-shaped front edge ( 5 ). 5. Cutting tool according to one of claims 2 to 4, characterized in that the cutting sonotrode ( 4 ') has a uniform width and tapers towards its front edge ( 5 ) in two stages. 6. Cutting tool according to one of claims 2 to 5, characterized in that the cutting sonotrode ( 4 ; 4 ') consists of TiAI6V4. 7. Cutting tool according to one of claims 1 to 6, characterized marked by a control unit through which the cutting tool ( 1 ; 1 ') can be regulated to a resonance frequency. 8. Plant for separating a film overhang ( 14 ) on a composite to be laminated, with means for positioning the composite ( 12 ), characterized by a cutting tool ( 1 ; 1 ') according to one of claims 1 to 7, which by a guide means ( 10 ) can be moved along the contour of the composite. 9. Plant according to claim 8, characterized by measuring means ( 11 ) which determine the distance between the cutting tool ( 1 ; 1 ') and the contour of the United bundle. 10. Plant according to claim 9, characterized in that the measuring means ( 11 ) determine the distance optically. 11. Plant according to claim 10, characterized in that the guide means ( 10 ) corrects the position of the cutting tool ( 1 ; 1 ') on the basis of the distance from the contour determined by the measuring means ( 11 ). 12. Plant according to one of claims 8 to 11, characterized in that the cutting tool ( 1 ; 1 ') can be excited to vibrate at a frequency of 40 kHz. 13. Plant according to one of claims 8 to 12, characterized in that the guide means comprises a freely programmable 6-axis robot ( 10 ). 14. Plant according to one of claims 8 to 13, characterized by stripping means which prevent the leaving of cut-off film ( 14 ) on the composite. 15. Plant according to one of claims 8 to 14, characterized in that the film protrusion ( 14 ) to be separated consists of polyvinyl butural. 16. Plant according to one of claims 8 to 15, characterized in that the composite comprises an outer and an inner glass plate ( 13 b, 13 a), between which the film overhang ( 14 ) protrudes. 17. Plant according to one of claims 8 to 16, characterized in that the composite consists of three parts, of which the two outer spherical components of composite windshields are to be connected by the film ( 14 ). 18. Installation according to one of claims 8 to 17, characterized in that the positioning means ( 12 ) relative to the guide means ( 10 ) is deliverable. 19. A method for separating a flat film ( 14 ) along a predetermined contour in space, preferably at a predetermined distance from the contour, characterized by the following steps:

• (a) positioning a cutting tool ( 1 ; 1 ') which can be excited to vibrate at a point on the contour; and
• (b) moving the cutting tool ( 1 ; 1 ') along the contour with separation of the film ( 14 ).

20. The method according to claim 19, wherein the cutting tool ( 1 ; 1 ') comprises a cutting sonotrode ( 4 ; 4 ') which is positioned and displaced such that it assumes a position substantially normal to the contour. 21. The method according to claim 19 or 20, that the film ( 14 ) along the contour in one cut without setting the cutting tool ( 1 ; 1 '). 22. The method according to any one of claims 19 to 21, in which during the positioning step and during the displacement step, the distance of the cutting tool ( 1 ; 1 ') to the contour is continuously detected and corrected to a target value. 23. The method according to claim 22, wherein the distance of the cutting tool ( 1 ; 1 ') to the contour is carried out by evaluating the image observed by a camera ( 11 ). 24. The method according to any one of claims 19 to 23, wherein the contour is that of a laminated safety glass to be laminated. 25. The method according to claim 24, characterized in that the film ( 14 ) consists of polyvinyl butural. 26. The method according to any one of claims 19 to 25, characterized by a learning step prior to the separation of film protrusions ( 14 ) for storing a new contour. 27. A method for producing curved laminated safety glass, in particular windshields, comprising the steps

• (a) Pairwise bending of an inner and an outer glass ( 13 a, 13 b);
• (b) separating the inner glass ( 13 a) and outer glass ( 13 b) and arranging a film ( 14 ) made of polyvinyl butural therebetween to form a composite; and
• (c) Laminating and then autoclaving the composite, characterized by a step of cutting back the film overhang ( 14 ) with the method according to one of claims 19 to 25 following step (b) and before step (c).

28. The method of claim 27, wherein the film (14) is drawn from a roll and the film (14) is separated only with the return of the film cutting projection (14) from the roll. 29. The method according to claim 27 or 28, characterized in that the cutting back takes place on a system ( 15 ) according to one of claims 8 to 18.