EP3507097B1 - Sheet-processing machine and method for monitoring the sheet travel - Google Patents

Description

The invention relates to a sheet-processing machine, in particular a sheet-fed printing machine or a sheet-punching machine, in particular a sheet-fed rotary punching machine, with a sheet system and with a device for monitoring sheet travel along a sheet transport path of the sheet system, and a method for monitoring sheet travel along a sheet transport path in an sheet machine.

For example, webs printed in a processing machine, in particular in a web-fed printing machine, receive a trimming cut during production which is within a tolerance range. As a rule, this tolerance range is between 0.1 and 0.15 mm. At the end of the printing process, these webs are cut into sheets with a cross cutter. These sheets can then be further processed as required, for example in sheetfed offset. For example, in the case of a refinement, the pre-printed subject can be imprinted or printed on. To do this, the pre-printed sheets must be created or aligned with a very high degree of accuracy.

From the DE 26 41 848 A1 A method and a device for positioning sheets for printing presses or the like is known, wherein the sheets are first mechanically pre-positioned by slidingly inserting them into a positioning device along a stop bar until the front edge of the sheet abuts a stop that is temporarily brought into the sheet path Then, with the help of marginal marks, the fine positioning is controlled in such a way that the marginal marks assigned to the front corners are successively brought into the scanning area of a respectively assigned electro-optical scanning device by correspondingly displacing the paper sheet, and finally the paper sheet is parallel to the sheet The stop bar is moved away until the edge marks assigned to the long side reach the area of the electro-optical scanning devices.

With one from the DE 36 44 431 A1 Known device, the actual position of the sheet to be aligned is determined by means of a measuring device on the feed table and compared in an evaluation unit with a predetermined target position. If the actual position deviates from the target position, an actuating signal is generated by which an actuator is actuated, which corresponds to the gripper system of a downstream drum. The gripper system is displaced by the actuator such that the sheet to be aligned held by the gripper system is brought into the desired position with respect to its side edge. In order to avoid that the measuring device detects incorrect measurements on the side edge when recording the actual position due to small damage or fibers DE 195 06 467 A1 proposed to provide at least three measuring devices working independently of one another. The measuring devices are arranged next to one another within a short section running parallel to the side edge to be measured, in order to determine a plurality of measured values. From the measured values which are determined for a position of the side edge, a measurement result is formed by means of a mathematical method which hides extreme values of the measured values which are due to anomalies of the side edge.

The DE 102 08 570 A1 describes a device for aligning sheets according to a side edge, in which the actual position of a sheet to be aligned, applied to front marks on a feed table, is recorded by a measuring device and the sheet is transferred to a gripper system of a drum by a sheet acceleration device, the gripper system being used for Realization of a target position is arranged displaceable in the axial direction.

From the DE 103 57 864 A1 a device for detecting the position of an edge of an arcuate material to be processed is known, an optoelectric Measuring device is assigned to a sheet hold-down device which fixes the sheet-like processing goods with the side edge on the feed table.

From the WO 2012/076671 A1 A method and a device for aligning a sheet in front of a sheet processing machine is known, wherein a sheet that has been transported is moved with its front edge against a stop and is thereby braked to a standstill, with the sheet on each longitudinal side in its front area in each case by a clamping device is clamped, a picture is then taken with a camera on the right and left front area of the sheet for determining the actual position, the image information of the camera is then compared with stored setpoints and the required correction movement to reach the setpoint position of the sheet is calculated and the stop on the leading edge of the sheet is then moved out of the transport plane and the calculated correction movement is carried out, the two clamping devices being moved independently of one another in and transversely to the transport direction.

From the DE 10 2010 027 119 A1 a method and a device for positioning sheets is known, wherein the positioning takes place without the use of front or side stops. The sheet is roughly positioned in the circumferential and inclined directions by controlled stopping of the sheet, a lateral alignment is carried out in the area of a feed table, and fine positioning in the circumferential and oblique direction is carried out by positioning register stops of a sheet transport system. The sheet positions can also be measured by measuring the sheet edge and print marks. A disadvantage of this solution is that the rough alignment by transport and pressing devices can also damage the printed image. It is also not easy to measure the position of the arc in the circumferential and oblique direction in motion.

From the DE 10 2008 012 775 A1 discloses a method for measuring the position of sheets and for aligning sheets, the sheets being moved over belts in the sheet transport direction over a feed table. A sheet is mechanically pre-aligned using front marks and side marks. In this pre-aligned position, a sensor detects the leading edge of the sheet or print marks printed on the sheet. To compensate for a difference between an actual and a target position, the sheet is corrected in its lateral position by a system for side alignment integrated in the feed table. The disadvantage of this solution is the alignment with side drawing marks and the necessary integration of the system for side alignment in the feed table.

From the DE 10 2009 027 861 A1 A method for the side edge alignment of printed sheets is known, wherein a respective printed sheet for side edge alignment measured by a sensor with regard to its side edge position is shifted from an actuating device on the feed table transversely to the transport direction on the feed table, without the respective print sheet being displaced transversely as a result of the displacement Transport direction comes to a plant on a side edge stop.

The invention has for its object to provide an alternative device or an alternative method for monitoring the sheet travel along a transport path of a sheet processing machine, in particular a sheet feeder. In particular, an improved sheet line without side draw marks or without large-scale pressing devices is to be created.

According to the invention, the object is achieved by a device with the features of the independent device claim and a method with the features of the independent method claim. Advantageous configurations result from the subclaims, the description and the drawings.

The invention has the advantage that an alternative device or an alternative method for monitoring sheet travel along a transport path of a sheet processing machine is created. In particular, an improved sheet system without side drawing marks and / or without large-area pressing devices is created.

The advantages that can be achieved in particular with the invention are that a sensor recognizes the pre-printed side marks on the sheet and the sheet is aligned via grippers in such a way that the pre-printed sheets can be applied or aligned precisely.

A rough alignment according to a detected side edge of the sheet and a subsequent fine alignment according to the mark or the printed image can be carried out particularly advantageously. The rough alignment makes it possible to create the time frame required for fine alignment according to brands or printed images, which is required for the recording and processing of the image content. A higher machine speed can thus still be achieved.

In a further development, a mark can be evaluated twice, with one evaluation unit processing both measurements in succession. The first measurement is preferably optimized for rapid evaluation in order to enable time-critical pre-alignment of, for example, a gripper system. A subsequent second measurement of the mark, preferably by the same sensor, is optimized for an accurate evaluation in order to enable a highly precise final control, for example of the gripper system. Thanks to the two-part measurement, on the one hand, positioning can be carried out quickly and, on the other hand, with high precision, resulting in faster machine speeds.

Fig. 1

eine Bogenanlage in der Seitenansicht;

Fig. 2

eine ausschnittsweise Darstellung eines Anlegtischs in der Draufsicht;

Fig.3 bis 5

eine schematische Darstellung möglicher Bogenlagen in Bezug auf zwei Empfänger;

Fig. 6

Darstellung einer Marke auf einem Bogen;

Fig. 7

Ausführungsform einer Bogenanlage einer Verarbeitungsmaschine;

Fig. 8

Draufsicht auf den Anlegtisch ohne auszurichtenden Bogen;

Fig. 9

Schnitt A-A aus der vorangehenden Zeichnung;

Fig. 10

Schnitt B-B aus der vorangehenden Zeichnung;

Fig. 11

Anlegtisch mit einem mindestens eine Druckmarke aufweisenden Bogen.

The invention is explained in more detail using an exemplary embodiment. Show in the accompanying drawings

Fig. 1

a bow system in side view;

Fig. 2

a partial view of a feed table in plan view;

Fig. 3 to 5

a schematic representation of possible sheet layers in relation to two receivers;

Fig. 6

Representation of a mark on a sheet;

Fig. 7

Embodiment of a sheet feeder of a processing machine;

Fig. 8

Top view of the feed table without an arch to be aligned;

Fig. 9

Section AA from the previous drawing;

Fig. 10

Section BB from the previous drawing;

Fig. 11

Feed table with a sheet with at least one print mark.

The Figures 1 and 2nd show a preferred sheet system, for example a sheet-fed printing machine, in particular a sheet-fed offset printing machine, preferably in unit and row construction, comprising a feed table 1 with front marks 2, a sheet acceleration device 3, which is preferably designed as a vibrating system 4 and has a sheet holding system 28, and a drum 5, in a gripper system 6 is arranged axially displaceable. A cylinder 9 is preferably arranged downstream of the drum 5. The upper table surface of the feed table 1 forms a sheet transport path, along which sheets 7, 8, 30 other organs of the sheet processing machine such. B. the bow support system 28 of the vibration system 4 can be supplied. A sheet 7 to be aligned, which is gripped by the gripper system 6, and a following sheet 8 are shown on the feed table 1.

The feed table 1 is preferably assigned a measuring device 10 which extends at least over a format range 12 which is characteristic of each machine, in which the side edge of the incoming sheets 7, 8, 30 can be detected. The format area 12 extends transversely to a conveying direction 11. In the exemplary embodiment, a channel 13 extending transversely to the conveying direction 11 is provided in the feed table 1, in which the measuring device 10 is arranged. The channel 13 is closed with a transparent cover strip 14, so that the surface of the feed table 1 and the cover strip 14 form a common plane. The measuring device 10 is an optoelectric measuring device 10, for. B. as a reflex line 15, CCD line or as a camera. However, any other measuring principle can also be used. The reflex line 15 preferably comprises a lighting device 16 extending over the entire length of the measuring device 10 and a receiver 17 located approximately in the same plane, in an adjacent position parallel to the lighting device 16 and also extending over the entire length of the measuring device 10. Alternatively or In addition to the arrangement of the receiver 17 shown, at least one receiver 29 can be assigned to the opposite side region of the sheet transport path.

A receiver 17, 29 can be formed from individual CCD elements connected in series or as a scanner line that extends over the entire format area 12. The CCD elements preferably consist of a multiplicity of measuring elements arranged side by side in a row. For the design of the receiver 17, 29, it is irrelevant whether this is part of the measuring device 10, whether an illumination device 16 is assigned to it, or what specific structure it has, provided that it is used for the optical detection of the lateral area of one or more superposed arches 7, 8 , 30 is formed. A single or each receiver 17, 29 can also comprise two CCD lines which are arranged inclined at different angles with respect to the sheet transport path. According to a further embodiment, an individual receiver or each receiver 17, 29 can also be arranged above the sheet transport path.

The receiver 17, 29 is connected to an evaluation unit 18. The evaluation unit 18 evaluates the signals of the at least one receiver 17, 29 to determine the position of the side edge of the one or the sheets 7, 8, 30 lying one above the other. Furthermore, the thickness of one or the sheets 7, 8, 30 lying one above the other can also be determined. Desired values for the lateral sheet position and possibly the sheet thickness can be entered or stored in the evaluation unit 18. The evaluation unit 18 is preferably linked to an actuating element 19 or a drive of the sheet-processing machine. The actuating element 19 can in turn be operatively connected to the gripper system 6 of the drum 5. The gripper system 6 preferably comprises gripper fingers 21 which are clamped on a gripper shaft 20 and correspond to gripper cuffs 22. The gripper system 6 is preferably arranged as a functional unit on a slide 24 which is slidably mounted in a drum channel 23. A driver 25 engages on the slide 24 and is connected to an actuating shaft 27 which is guided concentrically in a basic drum body 26. The actuating element 19 corresponds to the actuating shaft 27, by means of which the gripper system 6 can be displaced in the axial direction.

From one in Fig. 1 Belt table (not shown), the sheet 7 to be aligned is conveyed onto the feed table 1 and with the front edge against the front marks 2 located in a position on the feed table 1, brought to rest and thus aligned with the front edge. A selected side edge of the sheet 7 to be aligned, which is preferably at rest, is detected by the receiver 17, 29. For this purpose, when the receiver 17, 29 is designed as a reflex line 15, rays are preferably emitted by the lighting device 16, which rays are reflected from the underside of the sheet 7 to be aligned and are detected by the receiver 17, 29. In the area covered by the sheet 7 to be aligned, rays emitted by the illumination device 16 are reflected, so that the position of the side edge is reflected on the receiver 17, 29.

The suitable arrangement and design of the lighting device 16 and of the receiver or receivers 17, 29 can achieve that a side face of a respective sheet 7, 8, 30, that is to say a side face of the front, the rear, the upper and the lower side edge area of a respective arc side, included as a reflection area and imaged on the receiver 17, 29 or in other words detected by the latter. The arrangement of the lighting device 16 and the receiver 17, 29 is preferably implemented such that the light radiation emitted by the lighting device 16 or the radiation from any other light source on the underside of the respective arc 7, 8, 30 to a different extent, in particular a different proportion is reflected as from the side surface. On the receiver 17, 29, areas with different intensities are imaged according to the degree of reflection, which reflect their reflection source d. H. can be assigned to the underside of the respective sheet 7, 8, 30 or its side surface. The signal generated by the receiver 17, 29 is fed to the evaluation unit 18 and processed and possibly stored in it.

Thereafter, the sheet 7 to be aligned, which is to be aligned with the front edge on the front marks 2, is detected by the sheet accelerating device 3 and pulled off from the feed table 1, the front marks 2 being guided into a position under the feed table 1. If the sheet acceleration device 3 is designed as an oscillation system 4, the sheet 7 to be aligned is clamped by the sheet holding system 28 and subsequently pulled off from the feed table 1. A sensor 31 is arranged above the feed table 1 and determines a position of a mark 32 of the sheet 7, 8, 30, which is clamped in particular by the sheet holding system 28.

The measuring device 10 can, for example, already take a measurement to determine the position of the side edge of the sheet 7 when the sheet 7 runs in. This measurement can take place if the front edge of the sheet 7 has not yet reached the front marks 2, for example at a distance of 100 mm. Alternatively or In addition, a measurement can be carried out on the front marks 2 in the rest position of the sheet 7. In a first phase of the peeling, in which the front edge of the sheet 7 to be aligned 7 travels a distance s, where s can be approximately 2 to 10 mm, the position of the side edge of the sheet 7 to be aligned which is in motion is received by the receiver 17, 29 recorded in a sequence of measurements and the generated further signals are fed to the evaluation unit 18. A mean value is formed in the evaluation unit 18 from the first signal and the further signals of a measurement cycle, the values which exceed a predetermined tolerance, that is to say actual values which were initiated by anomalies in the side edge, being masked out and therefore not being taken into account. This mean value reflects the position of the side edge of the sheet 7 to be aligned and is compared with the target value stored in the evaluation unit 18. The evaluation unit 18 can also evaluate the signal of the receiver 17, 29 in relation to the thickness of the sheet or sheets 7, 8, 30 detected.

If the determined actual value of the sheet 7 to be aligned deviates from the target value, an actuating signal is generated by the evaluation unit 18 and fed to the actuating element 19. By the actuating element 19, after the sheet 7 to be aligned has been transferred from the sheet acceleration device 3 or vibrating system 4 to the gripper system 6 of the drum 5, the gripper system 6 is displaced in the axial direction to such an extent that the side edge of the sheet 7 to be aligned is removed from the Actual position has reached the target position. Subsequently, the aligned sheet 7 is transferred from the drum 5 to the cylinder 9 in the desired position. During the transport of the sheet 7 to be aligned to the drum 5, the following sheet 8 is transported with its front edge against the front marks 2 positioned on the feed table 1, aligned and brought to rest. The actual position of the side edge of the following sheet 8 is recorded in an analog manner by the measuring device 10 or reflex line 15 and fed to the evaluation unit 18.

If the value determined by the evaluation unit 18 for the thickness of a sheet 7, 8, 30 deviates upwards from a stored value, the evaluation unit 18 generates a multiple sheet signal and forwards this to at least one drive of the sheet processing machine for slowing or stopping it. The time at which the receiver or receivers 17, 29 optically detect the lateral area of one or more superimposed sheets 7, 8, 30 can vary according to various embodiments. In principle, it is possible to use one and the same signal for determining the thickness of one or more sheets 7, 8, 30 and to use the same signal to detect the position of the side edge of one or the sheets 7, 8, 30 lying one above the other, as well as different d. H. to use signals recorded at different times to determine the thickness of one or more sheets 7, 8, 30 and the position of the side edge of the one or more sheets 7, 8, 30 lying one above the other.

According to a preferred embodiment, the receivers 17, 29 detect a signal of the lateral region of one or more sheets 7, 8, 30 lying one above the other before the respective sheet 7, 8, 30 is aligned on its front edge, the evaluation unit 18 using this signal to determine the thickness evaluates one or the superimposed sheets 7, 8, 30. After the front edge of the same sheet 7, 8, 30 is aligned, a further signal is recorded with the same receiver 17, 29 and evaluated to determine the position of the side edge of one or the sheets 7, 8, 30 lying one above the other. This has the particular advantage that reacting to multiple sheets and machine damage can be prevented at an early point in time by activating the inlet lock, while the side edge of one or the sheets 7, 8, 30 lying one above the other is detected and evaluated comparatively late, ie after their alignment and a signal representing the position of the side edge is used to control an actuating element 19 after comparison with a desired value.

In the Fig. 3 a laterally offset single sheet 30 is shown in positional reference to an embodiment with two receivers 17, 29. The position of the side edges and the sheet thickness are recorded by both receivers 17, 29.

In the Fig. 4 Two sheets 30 offset to one another (ie a multiple sheet) are shown with respect to the position of an embodiment with two receivers 17, 29. Only the position of the left side edge and the thickness of the lower sheet 30 are detected by the receiver 17. The position of the side edges of the upper and lower sheets 30 and the thickness of the lower and upper sheets 30 are detected by the receiver 29.

In the Fig. 5 two laterally offset single sheets 30 are shown in the cover position (ie a double sheet) in relation to an embodiment with two receivers 17, 29. The position of the side edges and the sheet thickness of the double sheet 30 are recorded by both receivers 17, 29.

Fig. 6 shows marks 32 to be detected by at least one sensor 31 on a sheet 7, 8, 30. A mark 32 can be used as a register mark and / or code, e.g. B. as a QR code. The device for monitoring the sheet travel along a sheet transport path in the sheet feeder of a sheet processing machine comprises at least one sensor 31, which is assigned to the lateral area of the sheet transport track and is designed for optical detection of the lateral area of a sheet 7, 8, 30. The sensor 31 is arranged such that it has a position of a mark 32, e.g. B. a register mark of the sheet 7, 8, 30 determined. The sheet 7, 8, 30 preferably has the mark 32 even before the sheet 7, 8, 30 is fed into the sheet-processing machine. The sensor 31 is preferably arranged such that it detects the top surface of the sheet 7, 8, 30. The sensor 31 is particularly preferably arranged above the sheet transport path, in particular above the feed table 1 or the vibration system 4. The sensor 31 is advantageously transverse to Transport track slidably arranged. The sensor 31 is designed, for example, as a camera, CCD camera or CMOS camera. The sensor 31 is preferably connected to one or the evaluation unit 18, the evaluation unit 18 being arranged such that it can evaluate the signals of the sensor 31 for assessing the position of the mark 32. Depending on the signal from the sensor 31, the control element 19 is activated, for example a position of the gripper system 6 is changed. The signal from sensor 31 is preferably used for fine positioning of gripper system 6.

The evaluation unit 18 advantageously evaluates the signals from the measuring device 10 to determine the position of the side edge of the one sheet 7, 8, 30 and outputs a signal representing the lateral position of the sheet 7, 8, 30. The evaluation unit 18 preferably evaluates the signals of the receiver 17, 29 and the sensor 31 and forwards a signal representing the lateral position of the sheet 7, 8, 30 or a correction or actuating signal to the actuating element 19 for influencing the sheet position. The measuring device 10 for detecting the lateral area of the sheet 7, 8, 30 and the sensor 31 can be operated optionally, the measuring device 10 influencing in particular the rough positioning and the sensor 31 the fine positioning of each sheet 7, 8, 30. Each sheet 7, 8, 30 is aligned depending on both the measured values of the measuring device 10 and the measurement result of the sensor 31, with a rough alignment according to the side edge first and then a fine alignment according to the mark 32.

The Fig. 7 shows in one embodiment a sheet system of a sheet-processing machine, in particular as a further processing machine, in particular a sheet-fed offset printing machine in unit and series construction, as described above. The sheet feeder can also be part of a rotary punch. A sheet feeder can, for example, be provided in a material logistics system, for example in a printing room, in which a material to be processed is to be further processed, in particular refined. A printing material can be in sheet or roll form in an upstream Processing machine processed, for example printed, are. In the case of roll-shaped printing material, in particular in a preliminary process step, cross cutting is carried out to produce sheet-like processing materials, in particular sheets 7, 8, 30. Processed goods prepared in this way are fed to the sheet system of the sheet-processing machine for further processing. In particular, the sheet-processing machine can punch the sheets 7, 8, 30 and / or finish them in a finishing process, for example in a printing, coating and / or finishing plant. In particular, the sheet-processing machine can have a film transfer module for applying, for example, overprintable film layers for finishing.

In the upstream work step, in particular, at least one marking is made on the sheet-like processed material. For example, in an upstream printing process, for example on the web printing press, one or more marks 32 can be applied to the surface of the printing material, in particular to each of the later sheets 7, 8, 30, together with a particularly constant print image. The sheets 7, 8, 30 can, for example, be provided in stacks for further processing, in particular in a feeder upstream of the sheet feeder. For example, the machines provided for upstream processing and further processing can be from different manufacturers.

For the precise placement of the sheet-like processing goods, in particular the sheets 7, 8, 30, the sheet-feeding machine of the sheet-processing machine can have a belt table 33 with at least one perforated, preferably vacuum-loaded, continuously driven conveyor belt. The at least one conveyor belt can, for example, be provided at least approximately centrally with respect to the machine width. However, several conveyor belts can also be provided one after the other in the conveying direction 11 and / or next to one another. The vacuum can and / or the transport speed of the conveyor belts can also be individually controlled or regulated.

The conveyor table 33 is followed by the feed table 1 with the front marks 2 in the conveying direction 11. The upper run of the conveyor belt of the belt table 33 and the upper table surface of the feed table 1 form the sheet transport path, which in particular can represent a transport plane. A sheet 7 to be aligned is preferably in contact with the front marks 2 of the feed table 1. The sheet system further comprises a sheet acceleration device 3, which is preferably designed as a vibrating system 4 and has a sheet holding system 28, and a drum 5, in which a gripper system 6, not shown, is arranged so as to be axially displaceable. The machine can also be designed as described above and can comprise, for example, a cylinder 9, which is not shown after the drum 5.

The Fig. 8 shows a plan view of the feed table 1 without a sheet 7 to be aligned. In particular, a feed duct 13 extending transversely to the conveying direction 11 is provided in the feed table 1 in front of which the at least one measuring device 10 is arranged. The channel 13 is covered with a cover element, for example a scissor grid 14, the surfaces of the feed table 1 and cover element in particular forming a common plane. The side table sensors 17, 29 are preferably assigned to the feed table 1, in particular the channel 13, a respective active side edge sensor 17, 29 detecting a respective side edge of the incoming sheets 7, 8, 30, as described above. In particular, a side edge sensor 17 is assigned to a first side edge and a further side edge sensor 29 is assigned to the opposite side edge of a sheet 7. The sensors 17, 29 are designed in particular as optoelectric systems, for example as CCD lines or scanner lines.

The side edge sensors 17, 29 of a respective lighting device are preferred 16 arranged opposite one another, ie the lighting devices 16 are arranged above the feed table 1. For example, a side edge sensor 17, 29 can be moved or moved parallel and preferably together with the respective lighting device 16 transversely to the conveying direction 11. In particular, a respectively activated side edge sensor 17, 29 can be adjusted together with the associated lighting device 16 to the current sheet format, ie to the sheet side edge to be detected. The position control is preferably carried out according to a side edge sensor 17, 19, which is activated after a corresponding selection of the drawing side. In the embodiment shown, the side edge sensor 29 assigned to the side 2 is assigned a sensor 31 which detects the mark 32 of the sheets 7, 8, 30. However, the opposite side edge sensor 17 can also be connected to such a sensor 31.

The Fig. 9 shows the section AA from the preceding drawing with a camera 31 arranged above the feed table 1, with which a position of the mark 32 of the sheet 7, 8, 30 can be determined. The camera 31 is an optical recording system and preferably has a high resolution and / or associated evaluation software. The camera 31 is particularly preferably attached to a camera holder 34, on which the camera 31 can be displaced transversely to the conveying direction 11. For example, the camera holder 34 is mounted on a moving unit 35 for adjustment to the format width. The moving unit 35 can be accommodated, for example, in the channel 13 or below the feed table 1. Furthermore, the camera holder 34 can simultaneously accommodate the lighting device 16 for the side edge sensor 29. The camera holder 34 further preferably carries a hold-down device 36 facing the surface of the sheets 7. The hold-down device 36 can be arranged, for example, adjacent to or in one plane with the lighting device 16. The camera 31, the lighting device 16 and the hold-down device 36 can thus preferably be displaced together by the moving unit 35. The hold-down device 36 particularly preferably has a run-on slope for sheets 7 transported in the conveying direction 11.

The Fig. 10 shows the section BB from the preceding drawing, a sheet 7 to be aligned being conveyed from the upstream belt table 33 onto the feed table 1 and with the front edge against the front marks 2 located in a position on the feed table 1, brought to rest and thus aligned with the front edge. The hold-down device 36 has a cutout 37, which opens a field of view 38 of the camera 31. In particular, the recess 37 of the hold-down 36 is at least as large or larger than the field of view 38 of the camera 31. The camera 31 is always positioned so that a lateral sheet edge 39 lies in the field of view 38 of the camera 31. The camera 31 is positioned transversely to the conveying direction 11, in particular depending on the sheet format being processed.

The Fig. 11 shows the feed table 1 with a sheet 7 having at least one print mark 32. The sheet 7 is placed on the front marks 2 or on the stop surfaces of the front marks 2. The system is carried out here by the belt table 33 transporting the sheet 7, so that the sheet 7 is pushed against the front marks 2 and is thus aligned with an idealized contact line 40. The side edge sensor 29, which is set to the format on the lateral area of the sheet 7, can thus detect the position of the side sheet edge 39 and transmit measured values to the evaluation unit 18, so that an actuating element 19, in particular the gripper system 6 of the drum 5, can be actuated in and for its movement . The sheet leading edges are then fixed by the sheet holding system 28 of the vibration system 4 in the front pressure-free gripper edge 41, which can be up to 10 mm, for example. Subsequently, after the gripper of the sheet holding system 28 in the front pressure-free gripper edge 41, the print mark 32 is detected by the camera 31, the field of view 38 of the camera 31 being, for example, 30 mm in the conveying direction 11 and 20 mm transverse to the conveying direction 11.

The print mark 32 to be detected by the field of view 38 of the camera 31 can in particular be arranged in a pressure-free lateral area 42, which can extend from the lateral sheet edge 39, for example, up to 6 mm. The lateral pressure-free area 42 has, for example, an extension of 5 mm with a tolerance of 1 mm. The print mark 32 itself can have an extension in the conveying direction 11 of 12 mm and an extent transversely to the conveying direction 11 of 0.3 mm. The print mark 32 is in particular arranged at a distance of at least approximately 3 mm from the lateral sheet edge 39 with a tolerance of 1 mm. The print mark 32 is arranged at a defined distance, for example approximately 171 mm, from the front edge of the sheet 7, so that the print mark 32 comes to rest in the field of view 38 of the camera 31 when the sheet 7 is applied to the front marks 2.

On the mode of operation: the side edge or the side edge 39 of the sheet 7 to be aligned or which is preferably resting on the front marks 2 is detected by the side edge sensor 29. For this purpose, rays are emitted from the lighting device 16 arranged above the feed table 1, which are partially reflected by the sheet 7 to be aligned and partially detected by the side edge sensor 29. In the area covered by the sheet 7 to be aligned, the rays emitted by the lighting device 16 are reflected, so that the position of the side edge is imaged on the side edge sensor 29. The side edge sensors 17, 29 are each connected to the evaluation unit 18, which evaluates the signals of the at least one activated side edge sensor 17, 29 to determine the position of the side edge of one or the superimposed sheets 7, 8, 30, as described above. The evaluation unit 18 can also be part of the machine control.

The signal generated by the side edge sensor 29 is fed to the evaluation unit 18 and processed and possibly stored in it. The evaluation unit 18 generates control signals for the control means 19. The control of the control means 19, in particular the axial presetting or rough setting of the gripper system 6 of the drum 5, takes place preferably according to the measured values of the sheet side edge of the respective side edge sensor 17, 29. In particular, the gripper fingers 21 are pre-aligned against the determined later pull side. The rough positioning, in particular the axial pulling path limited by the gripper fingers of the sheet holding system 28 of the vibrating system 4 and the gripper fingers 21 of the gripper system 6 of the drum 5 can be at least approximately fully utilized or expanded.

Thereafter, the sheet 7 to be aligned with the front edge against the front marks 2 is detected by the sheet acceleration device 3, in particular the vibrating system 4, and is pulled off the feed table 1, the front marks 2 being guided into a position under the feed table 1. If the sheet acceleration device 3 is designed as an oscillation system 4, the sheet 7 to be aligned is clamped by the sheet holding system 28 and subsequently pulled off from the feed table 1. Preferably after the sheet 7 has been fixed by the sheet holding system 28 of the vibration system 4, the position of the mark 32 on the sheet 7 is recorded by the camera 31. The camera 31 is preferably designed such that it recognizes the print mark 32 independently, for example from the known shape or dimension of the print mark 32. The position of the print mark 32 can then be detected by the camera 31 or the evaluation unit 18, so that the Camera 31 can provide the measured values of the evaluation unit 18. The evaluation unit 18 evaluates the measured values of the print mark 32 for fine alignment of the actuating element 19, in particular of the gripper system 6, with deviations in the sheet position due to the gripper closure of the sheet holding system 28 being taken into account at the same time.

By the actuating element 19, after the sheet 7 to be aligned has been transferred from the sheet acceleration device 3 or vibrating system 4 to the gripper system 6 of the drum 5, the gripper system 6 is displaced in the axial direction to such an extent that the side edge of the sheet 7 to be aligned is removed from the Current situation in the target position. The values determined with respect to the detected print mark 32 are preferably used for fine alignment by the gripper fingers 21. Subsequently, the aligned sheet 7 is transferred from the drum 5 to the cylinder 9 in the desired position. During the transport of the sheet 7 to be aligned to the drum 5, the following sheet 8 is transported with its front edge against the front marks 2 positioned on the feed table 1 and measured and aligned in the same way.

In a further development in the first phase of the peeling, in which the front edge of the sheet 7 to be aligned travels a distance s, where s can be approximately 2 to 10 mm, the side edge of the sheet 7 to be aligned which is in motion could be moved by the side edge sensor 29, for example in a sequence of Measurements are recorded and the generated further signals are fed to the evaluation unit 18. These values are preferably ignored by the evaluation unit 18, but can be used, for example, for plausibility checking or the like.

Reference symbol list

1

Feed table

2nd

Front mark

3rd

Arc accelerator

4th

Vibrating system

5

drum

6

Gripper system

7

Sheet, sheet to be aligned

8th

Arch, follow-up arch

9

cylinder

10th

Measuring device

11

Direction of conveyance

12

Format range

13

channel

14

Cover strips, scissor grids

15

Reflex line

16

Lighting device

17th

Receiver, side edge sensor

18th

Evaluation unit

19th

Actuator

20th

Gripper shaft

21st

Gripper fingers

22

Gripper impact

23

Drum channel

24th

Sledge

25th

Carrier

26

Basic drum body

27th

Control shaft

28

Bow holding system

29

Receiver, side edge sensor

30th

Bow, single sheet, double sheet

31

Sensor, camera

32

brand

33

Conveyor table

34

Camera mount

35

Travel unit

36

Hold-down

37

Recess

38

Field of view

39

Sheet edge

40

Investment line

41

front pressure-free gripper edge

42

side pressure-free area

s

path

Claims (15)

1. A sheet-processing machine, in particular a sheet-fed press or sheet die cutting machine, having a sheet infeed, having at least one front edge stop (2) for feeding and aligning sheets (7, 8, 30), and having a device for monitoring sheet travel along a sheet transport path of the sheet infeed, comprising
   at least one measurement apparatus (10, 17, 29) for detecting a lateral sheet edge (39) of the sheet (7, 8, 30)
   and at least one sensor (31) that can be associated with the lateral region of the sheet transport path, which is designed for optical detection and determination of the position of a mark (32) on the sheet (7, 8, 30),
   wherein the measurement apparatus (10, 17, 29) and the sensor (31) are connected to an evaluation unit (18) which evaluates the signals for determining the location of the lateral edge (39) of the one sheet (7, 8, 30) and outputs a control signal to a control element (19, 6).
2. The sheet-processing machine according to claim 1, wherein the sensor (31) is arranged above the sheet transport path and/or above a feed table (1), and/or is designed as a camera, a CCD camera or CMOS camera.
3. The sheet-processing machine according to claim 1 or 2, wherein the sensor (31) is displaceably arranged perpendicular to the transport path and/or to a conveying direction (11) of the sheets (7, 8, 30) and/or at least one receiver (17, 29) is displaceably arranged below the sheet transport path and/or perpendicular to the conveying direction (11) .
4. The sheet-processing machine according to claim 1, 2 or 3, wherein at least one receiver (17, 29) of the measurement apparatus (10) is associated with both lateral regions of the sheet transport path.
5. The sheet-processing machine according to claim 1, 2 3 or 4, wherein an evaluation unit (18) processes the signals of a receiver (17, 29) and of the sensor (31) one after the other and forwards a signal influencing the lateral position of the sheet (7, 8, 30) to a gripper system (6) of a drum (5) arranged downstream from an acceleration apparatus (3, 4).
6. The sheet-processing machine according to claim 1, 2, 3, 4 or 5, wherein a holder (36) facing the sheet (7, 8, 30) with a recess (37) for a field of view (38) is associated with the sensor (31).
7. The sheet-processing machine according to claim 1, 2, 3, 4, 5 or 6, wherein the sensor (31) with a holder (36), an illumination device (16) and a receiver (17, 29) can be adjusted in format by means of a moving unit (35) in a channel (13) running perpendicular to the conveying direction (11).
8. A method for monitoring sheet travel along a sheet transport path in a sheet infeed of a sheet-processing machine, in particular a sheet-fed press or sheet die cutting machine having a device comprising at least one measurement apparatus (10, 17, 29) for detecting the lateral sheet region (39) of the sheet (7, 8, 30),
   characterized by at least one sensor (31) that can be associated with the lateral region of the sheet transport path, which is designed for optical detection of the lateral region of a sheet (7, 8, 30), wherein the measurement apparatus (10, 17, 29) and the sensor (31) are connected to an evaluation unit (18) processing the measurement values of the measurement apparatus (10, 17, 29) and the sensor (31) one after the other,
   wherein the evaluation unit (18) outputs a control signal to a control element (19, 6).
9. The method according to claim 8, wherein the measurement apparatus (10, 17, 29) is set to the format of the sheets (7, 8, 30) and/or detects the lateral sheet edge (39).
10. The method according to claim 8 or 9, wherein the sensor (31) is designed for optical detection and determination of the position of a mark (32) on the sheet (7, 8, 30) and/or is set to the format of the sheets (7, 8, 30).
11. The method according to claim 8, 9 or 10, wherein the respective sheet (7, 8, 30) is fixed between the measurements and/or wherein a mark (32) of the sheet (7, 8, 30) is detected after the sheet (7, 8, 30) has been fed and aligned on at least one front-edge stop (2).
12. The method according to claim 8, 9, 10 or 11, wherein the sensor (31) independently detects a mark (32) of a sheet (7, 8, 30), in particular by shape and/or dimension.
13. The method according to claim 8, 9, 10, 11 or 12, wherein the evaluation unit (18) determines control commands for a rough alignment or pre-alignment of at least one dripper system (6) arranged downstream from the measurement values of the measurement apparatus (10, 17, 29) and/or determines control commands for a fine alignment of at least one gripper system (6) arranged downstream from the signals or image signals of the sensor (31).
14. The method according to claim 8, 9, 10, 11, 12 or 13, wherein, after evaluation of the signals of the measurement apparatus (10, 17, 29), the evaluation unit (18) outputs a control signal for axial prepositioning against the determined traction side for a gripper system (6) of a drum (5) arranged downstream.
15. The method according to claim 8, 9, 10, 11, 12, 13 or 14, wherein a first detection of the lateral region (32, 39) of a sheet (7, 8, 30) by the measurement apparatus (10, 17, 29) is optimized for a rapid evaluation and a second detection of the mark (32) by the sensor (31) is optimized for a precise evaluation.

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