EP0747216B1 - Control for a printing machine - Google Patents

Abstract

The control system has a processor station (1'-5') associated with each operating unit (1-5) of the machine, with a communication bus (6) linking the processor stations for precise synchronisation of respective switching procedures for each operating unit. A further bus (8) is used to provide each of the processor stations with angular position information from an angle indicator associated with a rotating component at one of the operating units, for synchronisation of the switching procedures.

Description

The invention relates to a control for a printing press, in particular Sheetfed offset printing machine according to the preamble of claim 1.

Sheetfed offset printing presses of the type widely used today generally have so-called central controls, which in particular in the form of a PLC or. PC board control are built. It is also known to control the Functional division of the printing press. So a computer can be provided that permanent the switching states or signals of actuators, control buttons or sensors reads and a second computer in particular the main drive and the on the angle of rotation controls switching operations of the printing press related to moving machine parts. As So-called switching functions dependent on the angle of rotation are examples here Print on / print off the switching on and off of ink and dampening rollers, blocking the sheet inlet, switching the feeder and switching certain ones Functions called in the boom. These switching operations are time-critical, i.e. especially the positioning of the colored rubber blanket cylinder on the sheet-bearing Counter pressure cylinders may only follow the cylinders during channel correspondence if the first sheet to be printed is already on the impression cylinder.

A disadvantage in such a centrally constructed and implementing a sequential circuit Control is that the program structure in the computer of the control exactly on the Configuration of the machine must be switched off. A sheetfed press with one different number of printing units therefore requires a different number Programming the corresponding control. This is complicated significant, which is a clear trend towards the so-called In-line finishing or further processing exists. In sheetfed offset presses are often one or more after the last printing unit and before the delivery Painting facilities or other coating plants interposed. Since also in these devices must perform switching operations dependent on the angle of rotation position this function is also taken over by the central control.

A central control of the type briefly outlined above is known from DE 3 815 534 A1, which has a system for detecting the position of moving machine parts. For this purpose, the signals of a single-rotating shaft of the machine attached incremental encoder evaluated. This system evaluates not only the square-wave signals of the incremental encoder, which are phase-shifted by 90 ° but also the so-called zero impulses, which occur at each full, single-turn machine rotation. A central control with one such a system has the aforementioned disadvantages. Instead of one Incremental encoder can also be used to detect the position of moving machine parts a so-called absolute angle encoder can be used. However, this does not change anything Complexity of control that arises when a printing press is customized with a different number of units is equipped.

A control for rotary printing presses is known from EP 0 543 281 A1 which is assigned to each system part a computer representing the control and this Computer in the individual system parts for the purpose of signal exchange via a network designated bus system are interconnected. As a networking interface between the individual computers, ARCNET is proposed using a coax cable. How in this document, however, individual rotation-dependent switching operations are to be carried out not described.

DE 42 14 394 A1 describes a multi-motor drive for a rotary printing press known in which a number of cylinders and at least one folder each have a separate drive. The individual drives of the cylinders and their Drive controllers are grouped into pressure point groups, these pressure point groups are assigned to one of the folders and their position reference get from this folder. The administration of the pressure point groups takes place through a superordinate control system. The angular position values transmitted via the bus systems are used to generate synchronism, for example between two separately driven cylinders, but not triggering at certain angular positions switching operations.

DE 34 06 924 A1 describes a clock generation device for printing presses known in which the signals of a pulse generating device (scanning disks) in Connection with singular synchronous clocks fed to a pulse processing device which contains a memory designed as a PROM. So can Output signals for a large number of applications with specific rotational angle positions be provided to trigger certain functions (switching operations). This clock generation device with the circuit described provides a central control for a printing machine with several units.

DE 38 36 310 A1 describes a method and an arrangement for controlling Switching operations on a printing press are known, the printing press has several units such as feeder, delivery, printing units and that of the printing press assigned control at least one computer, a bus and one Includes angular position encoder. According to the at certain angular position values Switching operations to be triggered are setpoint angular position values in a memory of the computer stored, which by a running on the computer Program with the actual angular position values recorded via the angular position transmitter be compared. For certain events that can be recorded by the control appropriate switching operations are triggered when the angular positions are provided. Since the target angular position values for the switching processes to be triggered in stored on a computer and in this a computer with the corresponding If the actual angular position values are compared, this control provides a central control represents.

The object of the present invention is therefore a controller according to the preamble of claim 1 to expand in such a way that the disadvantages described above can be avoided and a high flexibility with regard to the equipment of the Machine is achievable.

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 addition to that the individual stations network Another bus is provided, via which the signals of the angular position of a Angle sensors are transferable, this angle sensor on a single-speed rotating Machine part of the printing press is attached. Through this angular position values transmitting bus system, each individual station receives information about the current present angular value. In the individual stations are corresponding to those on the bus transmissible events stored target angular position values so that the individual Stations trigger the intended switching processes in the assigned units can. As an example here is the logical switching off of pressure on one Missed / skewed and the coupling of the investor called.

According to a development of the invention it can be provided that the Printing machine on a single-speed rotating machine part a so-called Incremental angle encoder is arranged. The bus system provided according to the invention comprises a number of lines over which the individual against each other phase-shifted incremental signals are sent. The invention Bus system also has a further line, via which after each full Machine revolution a so-called zero pulse is sent. By such a thing Bus system ensures that switching operations are also carried out in the individual stations are resolvable, which only after a certain number of single-turn Machine revolutions are to be carried out based on the determined event. Be here again, as an example, the logical switching on and off corresponding to the paper run called the printing unit cylinder.

According to a further preferred embodiment of the invention, that in a unit of the printing press on a single-rotating machine part So-called absolute angle encoder is attached, which the the angular position corresponding digital values can be taken in parallel or in series. The The bus system provided according to the invention is then considered as a function of the resolution of the Absolute angle encoder adapted parallel or serial bus system. Also it is further developed here that not only angular values are provided via the bus system can be transferred resolved within one machine revolution, but additionally also signals which correspond to one full machine revolution at a time.

It was explained above that the incremental or absolute angle encoder Deliverable zero pulse used to determine integer machine revolutions can be. With incremental or absolute angle encoders, it is also possible to integer machine revolutions by summing the angular pulses or by to define a predetermined angle value of the absolute encoder.

As already shown above, the bus system according to the invention the individual stations in the units the angle values of a rotating on a single-speed Machine component attached angle encoder fed. Under a single-speed rotating The machine component of the printing press is in particular the plate cylinder Blanket cylinder, the simply large impression cylinder or for example one to understand the single-drum feed drum.

According to a development of the invention, it is provided that in addition to the Bus system as an event-driven, message-oriented communication system, i.e. as a bus system with one message-oriented protocol is formed. The CAN bus is preferred here (Controller - Area - Network) use. It is through such a trained bus possible that a station, which by sensors or other control means certain event detects a message of this event via this CAN bus transmitted and the stations then in the assigned units the intended Trigger angle-dependent switching processes. Here is an example Missed / misaligned sheet on the system of the first printing unit or a sheet loss between the second and third printing units. That of the respective unit assigned station and determining the event now sends via the bus system the Message "Missing sheet" or "Skewed sheet" or "Sheet loss between DW 2 and DW 3 "to the rest of the stations station assigned to the first printing unit, the processes in the first printing unit (e.g. print down).

Corresponding to those stored in the other stations for the receiving message Target angular position values now solve the respective switching processes in which in the assigned units (e.g. consistent print-Ab in the first printing unit downstream printing units and disengaging the feeder).

Fig. 1

die einzelnen Stationen mit dem Nachrichten- und dem Winkel-Bus,

Fig. 2 u. 3

die Ankopplung der einzelnen Stationen an einem Inkremental- bzw. Absolut-Winkelwerte übertragenden Bus-System.

Furthermore, an embodiment of the invention is explained with reference to the drawings. It shows:

Fig. 1

the individual stations with the message and the angle bus,

Fig. 2 u. 3rd

the coupling of the individual stations to a bus system transmitting incremental or absolute angle values.

1 to 1 to 5 individual units of a sheet-fed offset printing machine are indicated, where unit 1 is the feeder, units 2 and 3 offset printing units, unit 4 Painting unit and the unit 5 is a boom. The individual units 1 to 5 At least one computer 1 'to 5' is assigned to each of the stations The switching functions in the individual via interfaces and adjusting means, not shown Trigger units 1 to 5. So station 1 'takes over all switching functions for the unit representing the investor 1. In particular, the in-phase arrival and departure Switching off the investor mentioned. Stations 2 ', 3' and 4 'take over in the printing or Painting units of units 2 to 4 the corresponding on and off operations of cylinders arranged there. The station 5 'takes over the boom of the Sheet printing unit 5 all relevant for the delivery Switching processes such as, in particular, the one coordinated with the sheet travel, i.e. so too a certain angular position switching means for an automated Stack change or a sample sheet removal. The station 2 'in the first printing unit performing unit 2 is also with sensors for the sheet arrival at the System in connection - only one sheet control 9 is shown here. The individual Stations 1 'to 5' are connected to one another for signal exchange via a bus 6, this bus 6 as a message bus (CAN bus / controller area - network) is trained. Via the bus 6, the individual stations 1 '- 5' are also included a control center computer, not shown, and the main drive of the machine connected so that data for presets u. Like. To the individual computers and Running commands can be forwarded to the drive.

The station 2 'of the unit 2 which represents the first printing unit Sheetfed offset press has one attached to a single-speed shaft Angle encoder 7, which is connected on the one hand directly to the station 2 'and on the other about a further explained below and the angular values of this encoder transferred bus 8 to the other stations 1 ', 3', 4 'and 5' is connected. Each of the Stations 1 'to 5' have corresponding devices designed as an interface, by means of which the signals of the angle encoder 7 are continuously detected and read can.

Furthermore, the functionality of the embodiment variant shown here Invention using the example of a so-called missing sheet. Under a missing sheet understood a lack of a sheet on the system with the machine running. At a It is therefore absolutely necessary for such a missing sheet that the Blanket cylinders can be turned off by the impression cylinders to color the To prevent impression cylinders. Also the cylinder in the The coating unit (unit 4) must be switched off. Have the shutdowns described to be carried out in a logical manner in accordance with the sheet travel, so that they are still correctly in the Machine incoming sheets can be printed out.

The station 2 'of the unit 2 representing the first printing unit is located with a Bow control 9 in connection and evaluates the signal of this bow control 9 permanently out. At a certain point in time, station 2 'prevents the sheet from missing, so a missed sheet was found. In a memory of the station 2 'designed as a computer are stored angle values which correspond to those values for which the parking the printing unit cylinder has to take place in unit 2. The station 2 'now causes the locking of the system, the pre-gripper, in accordance with the predetermined angle values and then the parking of the blanket cylinder from the impression cylinder and that Parking opposite the plate cylinder in the first printing unit.

During the time at which station 2 'detects the missing sheet station 2 'enters the event "missed sheet in the first printing unit" corresponding signal on bus 6. In the memory of stations 1 ', 3', 4 'and 5' Also stored are angular values at which 1, 3, 4, 5 in these units switching measures to be carried out. After station 1 on the bus 6 has received the "Missing sheet in the first printing unit" event, is transmitted by station 1 ' the investor switched off. After a number of Revolutions is also caused by the message "Missing sheet in the first printing unit" received stations 3 ', 4', 5 'for the intended, stored angular values Pressure shutdown initiated. For this purpose, stations 1 'to 5' evaluate both the angle signals within one revolution as well as the total number of revolutions.

In the embodiment of the invention shown above, this was Printing shutdown described with a missing sheet. According to the sequence shown the other switching operations in the individual units 1 to 5 are also initiated. It is essential that the individual stations 1 'to 5' permanently Read in the angle setting values of the angle transmitter 7 and one of them via the message bus Event according to message from one of the stations 1 'to 5' to the other stations 1 'to 5' is sent and each of the stations 1 'to 5' the required Switching operations in the associated units 1 to 5 by comparing the detected executes current with the correspondingly saved angle values independently. A Another advantage of the permanent detection and evaluation of the angular position signals in the individual stations 1 'to 5' is also that the individual stations 1 'to 5' also regardless of the presence or receipt of a message / event can perform angle-dependent switching functions in the associated units. Here As an example, control the pendulum movement of a lifting roller, step by step Driving a duct roller, the powder matched to the sheet path electronically controllable drives or other devices during normal Called printing process. A decentralized control constructed in this way according to the invention is very advantageous for so-called time-critical functions.

Fig. 2 shows an embodiment of the invention, here the angle encoder 7 as a so-called incremental encoder is formed. Here, too, is the angle encoder 7 first printing unit of the unit 2 representing sheetfed offset printing press appropriate. Over a total of three lines, the station 2 'of the unit 2 each Incremental signals of tracks A and B and a phase-shifted from one another by 90 ° so-called zero pulse on the N track. The bus provided according to the invention points to the other stations 1 ', 3', 4 ', 5' for transmitting the angular position values also three lines so that here too the incremental signals of tracks A and B and the single-speed zero pulses N are transferable.

Fig. 3 shows a further embodiment of the invention, wherein here Angle encoder 7 is used, the so-called absolute angle encoder educated is. In this embodiment, it is provided that this angle encoder 7 on the as parallel bus system trained bus 8 the angle values at stations 1 'to 5' forwards. The bus 8 according to the invention for transmitting the angular position to the individual stations 1 'to 5' points according to the resolution of the Angle encoder 7 on a number of lines, it can be provided that on one another line, a so-called zero pulse is also transmitted, from which the individual stations 1 '- 5' the number of single-revolutions of the printing press can derive. The angle transmitter 7 is also on in the exemplary embodiment according to FIG. 3 the unit 2 representing the first printing unit of the sheet-fed offset printing press.

Reference list

1 - 5

Units (feeder, printing unit, coating unit, delivery unit)

1 - 5

Stations (computers)

6

Bus (news bus)

7

Angle encoder

8th

Bus (angle values of angle encoder 7)

9

Bow control

A, B, N

Signal lines of the incremental encoder (angle encoder 7)

Claims (8)

1. Control for a printing press, particularly an offset sheet printing press, with several units such as especially feeder, printing units, varnishing or coating units, delivery, wherein the control contains an angle sensor, at least one computer and a bus, wherein switching processes can be triggered via the computer in the case of certain current actual angle position signals in comparison with predetermined stored desired angular position signals corresponding to fixed events in the units, characterised in that fitted to each unit (1 - 5) is a station (1' - 5') comprising at least one computer, that the desired angular position values for switching processes to be triggered in one unit (1 - 5) are stored in the respective stations (1' - 5'), that a first bus (6) connecting the stations (1' - 5') for sending events generated in the stations (1' - 5') is provided, that a second bus (8) connecting the stations (1' - 5') is provided for transferring the actual current angular position signals and that via the stations (1' - 5') via an event sent across the first bus (6), the switching processes to be undertaken in the units (1 - 5) can be triggered in that the current actual value position signals transferred via the second bus (8) are compared with the desired angular position values stored in the respective stations (1' - 5').
2. Control for a printing press according to Claim 1, characterised in that the angle sensor (7) is arranged in that unit (1 - 5) of the printing press which represents the first printing unit of the printing press.
3. Control for a printing press according to Claim 1 or 2, characterised in that the angle sensor (7) is constructed as an incremental angle sensor.
4. Control for a printing press according to Claim 1 or 2, characterised in that the angle sensor (7) is constructed as an absolute angle sensor.
5. Control for a printing press according to one of the preceding claims, characterised in that from the angle sensor (7) additionally on each press revolution a zero impulse can be extracted.
6. Control for a printing press according to one of the preceding claims, characterised in that the bus (8) transferring the actual angular position signals is constructed as a parallel bus system.
7. Control for a printing press according to one of the preceding claims, characterised in that the bus (8) transferring the actual angle position signals is constructed as a serial bus system.
8. Control for a printing press according to Claim 7, characterised in that via the serial bus (8) on the press being stationary absolute angle values and during press running incremental signals can be transferred.

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