EP0936066A1 - Control device for a printing press - Google Patents

Abstract

The controller has several units, e.g. printing mechanisms and lacquering devices, associated with at least one station (2.1-2.3) with a computer. The individual stations are connected together by a first bus (6) carrying commands. The printer has an angle sensor (4) whose signals are passed to the stations over a second bus (7). The absolute angle sensor feeds an evaluation unit (5) that extracts absolute angle values from the sensor's incremental signals. Absolute angle values are conveyed by the first bus with the machine idle. With the machine active, the values passed over the first bus with the machine idle are processed to give current actual angle setting values using the incremental signals from the second bus.

Description

The invention relates to a control for a printing press according to the preamble of claim 1.

A large number of processes are dependent on sheetfed offset printing machines the angular position of the cylinders / rollers. These are examples Pressure switching, i.e. the on / off the blanket cylinder to the Plate cylinder or the impression cylinder. More depending on the angular position switching processes are in particular the format length of the substrate aligned switching of dryer devices, powder devices and sensors controlling the sheet travel. Sheetfed offset presses from widespread type usually have a central control in the form of a PLC or PC board control on. This control is on one with an angle encoder single-speed shaft in connection, so that the angular position values this Angle encoder within the control (a computer) with stored target angular position values compared for switching operations to be triggered accordingly can be. Such central controls have the disadvantage that this according to the equipment of the machine (number of printing units, coating and other inline finishing facilities) must be designed.

A control for a printing press is known from DE 195 20 919 A1 which the printing press several units such as feeder, printing units, Painting equipment, boom and the like. The individual units are assigned stations designed as computers, which via a particular connected to each other on a message-based protocol are. An absolute or incremental angle encoder is arranged on one of the units (single-revolving shaft), whose angular position values over a separate bus system (angular bus) to the individual stations. A detected in a unit via sensors arranged in the respective station Event is communicated to the other units via the first bus system, whereupon the functions to be triggered according to the determined event the station computers in the other units depending on the angular position signals triggered on the angle bus. This is done in the respective Station a comparison of the angular position signals present on the angular bus (Actual angular position) with target angular position values stored in the respective station.

In the above-mentioned document, incremental or Called absolute angle encoder. Accordingly, the angle bus is for transmission the angular position values as one of the incremental or absolute angular position values transmitting bus system. Becomes an absolute angle encoder and a parallel bus system for transferring the absolute angular position values used, such a training expensive because of the associated Wiring costs the bus system considerably. Also very much The use of a fast serial bus system is cost-intensive Transmission of the absolute angular position signals of an absolute angle encoder With a high resolution rate of the absolute angle encoder, however, do not have to only the bus system but also the interfaces in individual units Reading the angular position values should be designed to be correspondingly powerful.

The use of an incremental encoder as an angle encoder has the disadvantage that that an absolute angular position information in the form of a zero pulse only at Run of the machine can be obtained. Accordingly, after the start of the Machine does not depend on the angular position until the first receipt of a zero pulse switching operations to be triggered. On the other hand, it is advantageous the usability of an incremental bus for transmitting the signals of the incremental encoder because of the small number of lines and the lower Isolation effort.

The object of the present invention is therefore a control according to the Develop the preamble of claim 1 such that, while avoiding the Disadvantages mentioned above by reducing the construction effort an inexpensive design of a bus system that transmits angular position values is obtained.

This object is achieved by the characterizing features of claim 1. Further developments of the invention result from the subclaims.

According to the invention it is provided that in one of the units of the printing press an absolute angle encoder is provided, the absolute angle position signals converted into incremental signals by a downstream evaluation electronics are, these incremental signals during machine operation over the as Incremental bus trained angle bus to the individual stations (computers) of the Units are supplied. The evaluation electronics of the absolute angle encoder stands additionally with which the individual stations for the transmission of Switching commands connecting bus system in connection, so that at Machine standstill absolute angular position values at the other stations are transferable. This ensures that even when the machine is at a standstill each of the stations (computers) has information about the current one Angular position the machine is currently.

In the individual stations there are evaluation devices in the form of suitable programs stored or appropriate hardware modules (switchgear) installed, to the absolute values transmitted via the signal bus when the machine is at a standstill Angular position values in connection with the incremental signals when the machine is running permanent the necessary angular position signals in the form of actual angular positions to build. This is done according to a simple embodiment of the Invention in that the incremental signals of the transmitted the incremental signals Angular bus to that at the last machine shutdown over the Absolute angular position value transmitted in the signal bus can be added.

Fehlbogen Anlage" über das insbesondere auf einem nachrichtenorientierten Protokoll basierende Bussystem an die weiteren Stationen weitergeleitet. In jeder der einzelnen Einheiten (einzelnen Druckwerke) wird entsprechend dem Bogenlauf dann der Gummituchzylinder bei der dafür vorgesehenen Winkelstellung vom Gegendruckzylinder und sodann vom Gummituchzylinder abgestellt. Dazu werden in den einzelnen Einheiten (Druckwerken) in einer Auswertegruppe die jeweils aktuell vorliegenden Ist-Winkelstellungswerte - generiert aus den bei Maschinenstillstand übertragenen absoluten Winkelstellungswerten nebst den aufsummierten Winkelinkrementen - mit den für den jeweils vorzunehmenden Schaltvorgang vorgesehenen Soll-Winkelstellungswerten verglichen und bei einer Übereinstimmung der jeweilige Schaltvorgang ausgelöst. Das hier am Beispiel des Druck-ab-Schaltens im Falle eines Fehlbogens an der Anlage beschriebene Auswerten und Verarbeiten der Winkelstellungssignale in den einzelnen Einheiten erfolgt entsprechend bei anderen Ereignissen in der gleichen Weise.The switching functions to be performed in the respective units depending on the angular position can then be triggered by the actual angular position values that can be generated in this way in the individual stations. If, for example, a sensor detects a faulty sheet on the system in the unit representing the first printing unit of the machine, a corresponding command is issued

Missing sheet system "is forwarded to the further stations via the bus system, which is based in particular on a message-oriented protocol. In each of the individual units (individual printing units), the blanket cylinder is then parked at the intended angular position by the impression cylinder and then by the blanket cylinder in accordance with the sheet travel The individual units (printing units) in an evaluation group are compared with the currently available actual angular position values - generated from the absolute angular position values transmitted when the machine is at a standstill, together with the total angular increments - with the target angular position values provided for the switching operation to be carried out, and the corresponding switching operation is triggered if there is a match The evaluation and processing of the angular position signals in the individual units described here using the example of the pressure cut-off in the event of a faulty sheet on the system was carried out The same applies to other events in the same way.

According to a preferred development of the invention it is provided that each Station, for example, arranged in the evaluation group and an offset angle value containing memory, the content of which is permanent from the initial value of the counter of the evaluation group providing the current actual angle value is subtracted. This offset angle value is for the individual Stations of the units chosen in such a way that to be executed on a specific command Switching operations in each station with a uniform target angular position value can be triggered.

For the command Print-down "means, for example, that the corresponding target angular position value is uniformly at X _print-down degrees. Since the offset angle value in the individual stations of the printing units in this embodiment of the invention corresponds to the path of the printing material in angular degrees (angular distance or . angular difference) is set between two printing units, the output of the evaluation group (results from the incremental signals generated current angular position) minus the offset angle value of the respective printing station an individual for that station current angular position value. If the distance between two printing units DW _distance Degrees, for example the offset value in the first printing unit Off _{DW1 can be} set to = 0. In a sheet-fed printing _press with units of the same type which are lined up, this means that the offset value in the second, third, ... nth Printing unit Off _DW2 = 1 · DW _distance , Off _DW3 = 2 · DW _distance , ..., Off _DWn = (n - 1) · DW _distance ch the individual printing station each receive an individual actual angular _{position value} X _{DW1, ist} , X _{DW2, ist} , X _{DW3, ist} , ..., X _{DWn, ist} . These actual angular position values decrease with an increasing number of printing units, so that the switching times are generated in accordance with the sheet travel in the individual printing units with a uniform target value X _print-down for the print-off setting.

The advantage of the embodiment of the invention described above is that that in the stations (computers) the same units for each to be executed Commands must always save the same target angular position values. The only difference then is the offset angle values through which the modification the actual angle values take place.

With a sheet-fed printing machine that can be converted from perfecting to perfecting can, in addition to a first angle encoder (before the turn), a second one Angle encoder (after the turn) should be provided. The signals from the angle encoder, attached to the part to be rotated when moving the machine are then used for format-dependent positioning. When the machine is running can use the signals from the two angle sensors for monitoring the coupling device the turn can be evaluated in a suitable manner.

Furthermore, an exemplary embodiment of the invention is explained on the basis of the drawing.

Fig. 1

der erfindungsgemäße Winkelbus nebst dem Absolutwinkelgeber und die einzelnen Stationen, und

Fig. 2

die Winkelauswertung in einer der Stationen.

It shows:

Fig. 1

the angle bus according to the invention together with the absolute angle encoder and the individual stations, and

Fig. 2

the angle evaluation in one of the stations.

According to FIG. 1, a printing machine, not shown, has a plurality of units 1.1, 1.2, 1.3 in the form of an investor, one or more printing units, painting equipment as well as a boom. The individual units are 1.1 - 1.3 each assigned to stations 2.1 - 2.3 comprising at least one computer, by which the switching operations to be carried out in the respective unit 1.1 - 1.3 as well as monitoring the sheet travel (sensors - not shown), etc. become.

An angular encoder is located on a single-speed shaft of the printing press, not shown 4 in the form of an absolute angle sensor, to which an electronic evaluation unit 5 is connected downstream. According to the invention it can be provided that the evaluation electronics 5 integrated in one of the stations 2.1 - 2.3 of the units 1.1 - 1.3 is.

The individual stations 2.1 - 2.3 of the units 1.1 - 1.3 are connected to one another by a bus 6, which is based in particular on a message-oriented protocol (for example CAN bus), for exchanging signals in the sense of commands or messages. For example, an event can be detected within the stations 2.1 by appropriate sensors (e.g. Missing sheet system "), whereupon signals (message) representing the event are forwarded to the further stations 2.2, 2.3 via the first bus 6.

The individual stations 2.1 - 2.3 are through a second bus 7 as an angle bus connected with each other. This second bus 7 is designed as an incremental bus, i.e. over the lines of this bus 7 are corresponding to the rotation of the Machine and the resolution of the angle encoder 4 incremental signals. The second bus 7 is directly connected to the output of the evaluation electronics 5 of the angle encoder 4 connected. To generate the incremental signals for this Signals transmitting bus 7 is preferably the bit of the angle encoder 4 evaluated at the highest resolution and provided as incremental signals.

The evaluation electronics 5 of the angle encoder designed as an absolute angle encoder 4 stands over a corresponding interface with which the signal exchange between the individual stations 2.1 - 2.3 serving first bus 6 in connection. It is provided that when the machine comes to a standstill via the bus 6 each current and delivered by the angle encoder 4 angle value to the individual Stations 2.1 - 2.3 is sent.

The individual stations 2.1-2.3 have suitable hardware components (Interfaces, bus couplers and the like) as well as corresponding program routines realized evaluation groups 3.1 - 3.3, each with one input with the Signal exchange and the transmission of the absolute angular position values (at Machine standstill) bus 6 and the transmission of the incremental signals serve bus 7 are connected.

2 shows the basic components of an evaluation group 3.1 in detail. At this Embodiment variants of the invention are those via the bus 6 when the machine is at a standstill transferable absolute values of the angle encoder 4 a first input a loadable counter 8 fed to the evaluation group 3.1. This loadable counter 8 is via a second input with that of the transmission of the incremental signals serving second bus 7 connected such that the machine running on this Counter 8 applied signals of bus 7 increase the absolute value in counter 8 and this provides the corresponding value at the output as the actual angle value.

The output of the counter 8 containing the current actual angle value becomes one Totalizer 9 supplied, on the other hand with that contained in a memory 10 Offset angle value is related. Through the totalizer 9 because of the sign of the sizes to be linked, shown in FIG Subtraction of the offset angle value from that provided by the counter 8 current actual angle value. Thus station 2.1 stands around the offset angle value corrected angle value is available, which is indicated by a connection Computer system of the station 2.1 is supplied. With these for the respective Offset angle value corrected actual angular position values are then compared with the target angular position values stored in station 2.1, in order to over the events / commands transmitted in bus 6 in unit 1.1 Carry out switching operations or actions.

Reference list

1.1 - 1.3

unit

2.1 - 2.3

Station (computer)

3.1 - 3.3

Evaluation group (station 2.1 - 2.3)

4th

Angle encoder (absolute angle encoder)

5

Evaluation unit (angle encoder 4)

6

Bus (signal exchange between stations 2.1 - 2.3)

7

Bus (transmission of incremental signals)

8th

Counter (evaluation group 3.1 - 3.3)

9

Totalizer (evaluation group 3.1 - 3.3)

10th

Memory (evaluation group 3.1 - 3.3; offset angle value)

Claims (4)

Control for a printing press, in particular sheetfed offset printing press, the printing press having a plurality of units such as feeders, printing units, coating devices, delivery units and the like. The units are each assigned at least one station having a computer, the individual stations via a first bus for transmitting commands to one another are connected and the printing press has an angle transmitter, the signals of which can be fed to the individual stations via a second bus,
characterized,
that the angle encoder (4) is designed as an absolute angle encoder with a downstream evaluation unit (5), from which incremental signals and absolute angle values that can be generated by the angle encoder (4) can be obtained, that the absolute angle values of the evaluation unit (1) when the machine is at a standstill 5) of the angle encoder (4) that the second bus (7) is designed as a bus which transmits the incremental signals of the evaluation unit (5) and that when the machine is running in each of the stations (2.1 - 2.3) the bus (7) 6) the absolute angle values of the angle transmitter (4) transmitted when the machine is at a standstill can be processed in connection with the incremental signals of the second bus (7) to give the current actual angle position values. Control according to claim 1,
characterized,
that incremental signals can be generated by the evaluation unit (5) from the bit of the angle encoder (4) with the highest resolution and can be fed to the second bus (7). Control according to claim 1 or 2,
characterized,
that the stations (2.1 - 2.3) each have an evaluation group (3.1 - 3.3) with a loadable counter (8), which has a first input with the first bus (6) for taking over the absolute angle values sent when the machine is at a standstill and with a second input is connected to the second bus (7) for taking over the incremental signals, and that the absolute angle value can be summed up according to the incremental signals by the counter (8) when the machine is running and the value of the counter (8) at an output as the current actual angle value to the computer system the stations (2.1 - 2.3) can be fed. Control according to claim 3,
characterized,
that the evaluation groups (3.1 - 3.3) each have a memory (10) linked to the output of the counter (8) via a summator (9), which memory contains an offset angle value, that the offset angle value of by the summer (9) the angle value present at the output of the counter (8) is continuously subtracted, and that the difference value present at the output of the summer (9) can be supplied to the computer system of the stations (2.1-2.3) as the current actual angle value.

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