EP0692377A2 - Method and device for the synchronous driving of printing machine components - Google Patents

Abstract

The drive system has respective operating drives (7) for the synchronised machine components (2,..6) coupled via a required value control signal, each motor regulated in dependence on the difference between this required value control signal and an actual signal. The required value control signal is provided by using an actual value signal for a given machine component and an actual value signal obtained from the drive for the same machine component. <IMAGE>

Description

The invention relates to a method and a device for the synchronous driving of printing press components by means of coupled drive motors.

Known printing machines for printing web-shaped materials are equipped with a longitudinal shaft running along the machine, which ensures precise synchronous operation of one or more drive motors. The individual components of this machine, for example printing units, folders, web tension members and the like, are driven from this longitudinal shaft by mechanical gears and couplings. Although a synchronous run of the individual printing press components is achieved here, the elastic flexibility of the mechanical transmission elements can have an effect on the print quality of the printed product when accelerating or decelerating. Such a mechanical transmission chain with a longitudinal shaft On the one hand, synchronization is very complex, since a large number of individual parts are required; on the other hand, the transmission chain also hinders access to the individual printing press components and furthermore makes autonomous use of machine components difficult during set-up operation.

A printing machine without a longitudinal shaft is known from DE-A 41 38 479. The actuators of the printing press components are driven individually with directly attached drive motors. In this case, the mechanical transmission chain for synchronizing the printing press components is saved, but a large number of directly driving motors with correspondingly high-precision controls must be used for this. This solution is therefore complicated and expensive.

Solutions are also known in which the elastic compliance of the mechanical transmission elements during acceleration and deceleration of the machine are stabilized by monitoring the position of individual monitoring elements. Examples of this are known from DE 42 10 988 A1 and EP 0 446 641 A2. With these solutions, the elastic compliance of the mechanical transmission elements between the press components during acceleration and deceleration can be better controlled, but the disadvantages of a relatively complex assembly, poor accessibility and the restrictions with regard to autonomous operation of press components are not eliminated.

DE 33 18 250 A1 teaches a regulating and control device for the synchronous drive of a web-fed rotary printing press with mechanically uncoupled main drive motors. For this purpose, the main drive motors, ie their motor controllers, are coupled to one another via a common control line. The motor controllers receive their setpoint via the control line in the form of a so-called reference frequency for setting the desired setpoint speed. At one point in the power transmission path between a main drive motor and the driven load, ie the printing press component, a rotary pulse generator is arranged to determine the actual speed value. Its output signal is also fed to the engine controller. The individual motor controllers thus receive a setpoint control signal and a locally approved motor control Actual value from which the motor controller uses a suitable control algorithm to generate the output signal for controlling the respective drive motor. Problems will arise with this known motor control if the printing machine components acting as loads have different elasticities. The differences between the measured actual values and the setpoint value supplied via the control line due to the different elasticities of the loads or the transmission elements from the drive motors to the loads increase in the worst case from one printing machine component to another, which inevitably leads to tension and pressure quality-reducing deviations, in particular when accelerating or decelerating the machine.

The object of the invention is to enable the synchronous running of printing press components at any time, in particular also during an acceleration phase, for example while the machine is starting up, but also after longer periods of printing.

This object is achieved by the subject matter of the independent claims.

The respective subordinate claims are directed to advantageous, not completely self-evident embodiments of the invention.

The invention is based on a method for synchronously driving printing press components, in which drive motors of printing press components are coupled to one another by a setpoint control signal and the drive motors coupled in this way are regulated as a function of a deviation between the setpoint control signal and a suitable actual value signal. The setpoint control signal can be a speed signal or a position signal, for example an angular position to be set, for the loads, namely the printing press components, or the drive motors. The actual value signal designated as suitable can be taken from the motor, at a point in the transmission path from the motor to the driven load, or preferably at the torque-free end of this load.

According to the setpoint signal in certain operating conditions, for. B. speed changes when starting up the press or after system component run-in processes are not simply generated, but are adapted by an actual value signal of a press component. Since the adjusted setpoint control signal assumes the function of the coupling between the drive motors and is not simply predefined from the outside, for example by a corresponding generator of the system control, but is changed in accordance with a suitable control algorithm depending on the actual values that are set on the printing press components , the drive motors can be optimally regulated and controlled according to the required accuracy.

The actual value of a printing press component or a drive motor can be used. An actual value signal of a printing press component and a corresponding actual value signal of an associated drive motor are preferably used simultaneously to form the setpoint control signal. Taken together, these two actual value signals contain almost complete information about the drive-load system of the printing press component and the associated drive motor. If, in continuous printing at constant speed, the differences between the actual value signals of the individual printing press components are compared with one another and monitored for limit values, then with pure speed control over a longer production time, accumulating phase position errors can be avoided by suitable control processes.

By forming differential signals between the actual values of the printing press components to be synchronized and their coupled motors, the different elasticities can be largely taken into account and corrected. By using not only an actual value on the drive motor or on the printing press component, but both actual values assigned to one another, preferably the phase angle between the two corresponding actual values, a good tooth flank contact of the individual members of a multi-part printing press component, for example a printing unit consisting of several cylinders and rollers, can be achieved. be ensured. Taking into account such an actual / actual difference according to the invention ensures that there is never too much elastic energy in the motor-load path.

It proves to be advantageous to use a predetermined master frequency signal as the setpoint specification signal and to modulate it with the two actual value signals or the difference signal formed from these two actual value signals to form the setpoint control signal.

The use of actual value signals to form the setpoint control signal is particularly advantageous when accelerating and decelerating the machine as well as any speed limits in run-in processes, i.e. in operating phases in which different elasticities of the printing press components and different engine characteristics have a particularly disadvantageous effect. On the basis of the invention, acceleration or deceleration smoothing takes place during the entire acceleration or deceleration process and, at the end of both phases, when transitioning to constant running, the speed of the printing press components ramping in the speed-time diagram takes place. Exceeding the speed due to the stored elastic energy, which accelerates the load at the moment when the drive motor has already changed over to constant running, can thus be counteracted smoothing. Otherwise, especially in the transition phase, the web to be printed would be stretched between the individual printing press components in an unpredictable manner.

According to the invention, the control system selects the actual value signal which has the greatest deviation from the setpoint specification or the largest actual / actual difference to form the setpoint control signal. A pair consisting of a printing press component and an associated drive motor is thus always determined as the master for the synchronization. A simplified version of the system consists in forming the setpoint control signal on the basis of the difference between an actual press component load signal and the setpoint value signal which has not yet been adjusted.

After a longer period of printing, errors in each of the controlled driven press components can gradually add up inadmissibly. It can happen that the errors between the components compensate to some extent, but due to the drift of the engine governor, which can never be completely prevented, there can also be a gradual summation and thus a drift that leads to it prevent applies. For this reason, the differences between the actual value signals of the individual printing press components and the setpoint control signal or the differences between the individual actual value signals of the printing press components among themselves are checked for exceeding a maximum permissible difference. If one of the two differences is exceeded, adjustment is made. In this way, errors that add up over time and that result in web drift and not just individual drift of printing press components can be avoided by rule drifts. For this purpose, the system component drive motors can be controlled via an individual setpoint correction signal.

While the actual values to be used for readjustment are periodically queried by the control system during the acceleration and deceleration phase of the machine, a random sample-like query of the relevant actual values is generally sufficient when the web is continuously running while the machine is being printed. As a result, the readjustment processes in the production run are further reduced.

The present invention can be used in such printing machines, in particular rotary printing machines, the components of which, namely the printing units, folders and the like, are also mechanically connected, for example by means of corresponding gearwheel trains. However, it is preferably used for autonomously driven printing press components. These printing press components can be driven by several drive motors. In a preferred embodiment, the printing press components are equipped with a single drive motor or with a main drive motor which is coupled to the drive motor (s) of other printing press components by the setpoint control signal.

It is also advantageous to combine the pressure cylinders and their counter-pressure cylinders to form a pair of cylinders by mechanical coupling and to drive them in pairs by means of a motor. This is disclosed in the two patent applications P 43 44 896.8-27 and P 44 05 658.3, the teachings of which are referenced with regard to the combination of cylinders into self-propelled cylinder groups. In this case, the printing press components can also be formed by these cylinder groups. A Regulation of such cylinder groups, namely only with a load sensor, preferably at the torque-free end of the directly driven cylinder, is taught by patent application P 43 44 912.3. This teaching can also be used with advantage in the present invention, it being understood that further actual values of cylinder groups can of course be used for the synchronization according to the invention.

In the event that inking rollers are used in the printing press, which are not driven by the printing cylinders themselves, but independently, these can be controlled analogously to the system components via the master frequency and multiplication factors. The advance factors can be predetermined or adjusted by the control depending on the respective inking roller contact pressure or radius.

The invention is explained below using a preferred exemplary embodiment.

Figur 1

Eine beispielhafte Rotationsdruckmaschine mit mehreren Druckmaschinenkomponenten;

Figur 2

eine erfindungsgemäße Anordnung zum synchronen Antreiben von in Figur 1 dargestellten Druckmaschinenkomponenten.

Further features and advantages are disclosed. Show it:

Figure 1

An example rotary press with multiple press components;

Figure 2

an arrangement according to the invention for the synchronous driving of printing press components shown in Figure 1.

1 shows a roll changer 2, a pretensioner 3, printing units 4, a superstructure tension member 5, a folder 6 and a former roller 17 for a conventional web-fed rotary printing machine as printing machine components, which are synchronized by a master frequency coupling according to the invention. Drive motors 7 with motor sensors 8 and load sensors 9 assigned to these printing press components are also shown.

FIG. 2 shows a regulating and control arrangement for the printing press components 2, 3, 4, 5, 6 and 17. This is a master frequency coupling of the drive motors 7 of the printing press components. The drive motors 7 are controlled by a motor controller 10. A motor encoder 8 is provided for each of the motor controllers 10. which outputs an actual value signal I 1 representing the speed or the position of the respective motor 7 to the controller 10 of this motor 7. As a second input signal, each motor controller 10 is supplied with a setpoint value signal V via a line bus 14 from a master frequency generator 12. The speed setpoint specification signal V is received by all motor controllers 10 in real time via a line bus 14. The motor controller 10 uses this to generate the respective control signal R for each of the drive motors 7 according to a suitable control algorithm. The drive motors 7 then drive their respective printing press components, in particular the printing units 4, of which only a directly driven blanket cylinder and its impression cylinder are shown in FIG. 2.

At the torque-free end of one of the cylinders of the driven cylinder pair of such a printing unit 4, preferably at the load-free end of the driven blanket cylinder, the load transmitter 9 is arranged for measuring and outputting a suitable actual load value I₂ for the control. In the exemplary embodiment, the printing units 4 and the folder 6 are equipped with such loaders 9. Basically, it would also suffice to provide only the pressure units 4 with loaders 9.

The alternative supply of the signal I₂ of the load generator 9 to the respective motor controller 10 is also shown in dashed lines. In this case I₂ would be used instead of I₁ for engine control.

In the case of the printing press components for web guiding, such as reel changer 2, pretensioner 3, superstructure drawing roller 5 and funnel roller 17, a play-free direct drive via a corresponding coupling or toothed belt is also possible instead of the individual drives. For this reason, one of the sensors 8 or 9 can be dispensed with in these components.

The actual values I₁ and I₂ from the pairs of motor and load sensors 8 and 9 are each fed back to a machine control 13 via feedback lines 28 and 29. The phase shift between the respective pairs of motor sensors 8 and load angle sensors 9 is monitored by the controller 13.

The motor controllers 10 of the printing units 4 and of the folder 6 are equipped with address decoders 10.1 so that the machine control 13 can address them individually. The actual value signals I₁ and I₂ are each fed via a return line 28 and 29 to the machine control 13. The actual values I₁ and I₂ of the respective system components with each other or the actual value I₁ or I₂ of an individual system component for the setpoint input signal (V) are monitored in order to determine the drift in the production run. From this, a correction signal K for the respective printing unit 4 and the folder 6 is formed each time predetermined limit values are exceeded and is guided by the control via a line 16 together with an associated address signal via the address decoder 10.1 into the relevant motor controller 10. In addition to the address decoders 10.1, the motor controllers 10 of the printing units 4 and of the folder 6 each have a setpoint / actual value comparator 10.2 and a power unit 10.3. The comparator 10.2 of each printing unit 4 and the folding apparatus 6 are supplied with three signals, namely the correction signal K via line 16 or address decoder 10.1, the actual motor value I 1 and via line 14 the setpoint value signal V from the frequency generator 12. The individual control is thus formed as a function of the correction signal K transmitted on line 16 and the setpoint value signal V on line 14 for each printing unit 4 or the folder 6 in the respectively assigned motor controllers 10. The control signals are formed from the individually formed desired value control signals S and the individual actual values I 1 and, after amplification in the power sections 10.3, the motor controller 10 is fed as control signals R to the respective motor 7.

When the machine is started, the frequency generator 12 generates the setpoint specification signal V on the basis of the speed specification of the controller 13. With the signal feedback circuits 28 and 29, the setpoint specification signal V can then be used on the bus 14 in accordance with the acceleration smoothing to the setpoint control signal S supplied to all coupled printing press components be adjusted. At a constant speed, such a global setpoint control signal S corresponds to the setpoint input signal V.

For the web guiding elements 2, 3, 5 and 17, it is necessary to ensure that the correct web tension is applied to the setpoint signal V advance factors. This is done by the controller 13 and a line bus 15 via the respective motor controllers 10 assigned advance multipliers 11, each with an address decoder 11.2 and the actual multiplier 11.1. Instead of the advance control, a web tension control according to the prior art can also be used on these web guiding elements.

In a further embodiment of the bus structures, the signals (15, 16) can take place via a single bus connection.

To compensate for intolerable error summations between the individual printing press components in production printing, the signals of the individually addressable motor and load sensors 8 and 9 are checked by the controller 13 in a random sampling process. Mechanical register adjustments on the printing cylinders are automatically recognized by the control 13 and taken into account in accordance with a higher-level machine program.

For the drift correction in the production run, a query and correction algorithm is advantageously processed using fuzzy logic.

According to a likewise preferred embodiment, the setpoint control signals can be formed centrally with a correspondingly designed machine generator 12 and machine control 13. In this case, address-coded setpoint control signals S are routed to the motor controllers 10 via the line bus 14. The formation of the setpoint control signals S is shifted from the engine controllers 10 to a central unit formed by the generator 12 and the controller 13. Corresponding adjustments would have to be made with regard to the advance multipliers for the train bodies.

According to a further simplified embodiment of the invention, the same setpoint control signal S is always fed to the printing units 4 or the folder 6 via the bus 14. In this case, the address decoder 10.1 of the motor controller 10 can be omitted.

Claims (21)

Method for synchronously driving printing press components, in which a) a drive motor (7) of a first printing press component (4) and a drive motor (7) of a second printing press component (4) are coupled to one another by a setpoint control signal (S) and b) the coupled drive motors (7) are regulated as a function of a deviation between the setpoint control signal (S) and a suitable actual value signal (I₁, I₂), characterized in that
c) to form the setpoint control signal (S) a setpoint input signal (V) and an actual value signal (I₁, I₂) of a printing press component (4) or a drive motor (7) are used. Method according to Claim 1, characterized in that the actual value signal (I₁) of a printing press component (4) and the actual value signal (I₂) of a drive motor (7) of the same printing press component (4) are used to form the setpoint control signal (S) become. Method according to Claim 1 or 2, characterized in that the actual value signal (I₁, I₂) used to form the setpoint control signal (S) and the suitable actual value signal (I₁, I₂) used to control a drive motor (7) is identical. A method according to claim 2 or 3, characterized in that to form the setpoint control signal (S) a difference signal (I₁-I₂) between the actual value signal (I₁) of a printing press component (4) and the actual value signal (I₂) of the drive motor (7) is used. Method according to one of the preceding claims, characterized in that, in order to form the setpoint control signal (S), the setpoint input signal (V) is frequency-modulated with the actual value signal (s) (I₁, I₂) or the difference signal (I₁-I₂). Method according to one of the preceding claims, characterized in that a setpoint control signal (S) only in the event that a limit value for a maximum permissible deviation of an actual value signal (I₁, I₂) from the setpoint input signal (V) or for an actual value is exceeded -Difference (I₁ - I₂) is formed. Method according to one of claims 1 to 6, characterized in that a) the actual values (I₁, I₂) of the printing press components (4, 6) and / or drive motors (7) are queried, b) the deviations between the target value and the queried actual values (I₁, I₂) or the actual value differences (I₁ - I₂) between the system components are determined and c) the deviations are then compared with one another and individual correction signals (16) are formed for the corresponding system components when permissible limit values are exceeded. Method according to claim 7, characterized in that the actual values (I₁, I₂) are queried in a random sampling process. Method according to one of the preceding claims, characterized in that the suitable actual value signal (I₁, I₂) used to regulate a drive motor (7) is an actual value signal of this drive motor (7) or one at a torque-free end of the one driven by this motor Printing machine component (4). Device for synchronously driving printing machine components, a) with a motor controller (10) for at least one drive motor (7) of each printing press component (4), b) with an actual value transmitter (8, 9) for each motor controller (10) for outputting an actual value signal (I₁, I₂) which can be assigned to the respective printing press component (4), c) with means (12, 13, 10.2 or 12, 13) for generating a setpoint control signal (S), wherein d) the motor controllers (10) an actual value signal (I₁, I₂) of their actual value transmitter (8, 9) and via at least one common control line (14 or 14, 16) the setpoint control signal (S) or a setpoint input signal (V) are supplied to form engine control signals (R), characterized in that
e) to form the setpoint control signal (S) from the setpoint signal (V) and an actual value signal (I₁, I₂) of an actual value transmitter (8, 9) a feedback line (28, 29) of at least one of the actual value -Giver (8, 9) to a machine control (13) is provided. Apparatus according to claim 10, characterized in that an actual value transmitter (9) for outputting an actual value of the printing press component (4) and an actual value transmitter (8) for outputting an actual engine value are provided for a printing press component (4). Apparatus according to claim 11, characterized in that each printing press component (4) has a pair of actual value transmitters (8, 9). Device according to one of claims 10 to 12, characterized in that the actual value transmitter (8, 9) is connected to the controller (13) via a return line (28, 29). Device according to one of claims 10 to 13, characterized in that a comparison circuit is provided, the actual values (I₁, I₂) and / or the setpoint input signal (V) on the input side for determining the greatest deviation between the actual values (I₁, I₂) or determined between one of the actual values (I₁, I₂) and the target value specification, and that the value of the greatest deviation is processed further. Device according to one of claims 10 to 14, characterized in that the unit for generating the setpoint control signal (S) comprises a controller (13) and an associated frequency generator (12), the setpoint value signal generated by the frequency generator (12) (V) a signal is modulated on by the controller (13) to form the setpoint control signal (S), which signal represents a difference signal which consists of an actual value (I₁) of a motor encoder (8) or an actual value (I₂) of a load encoder (9) a first printing unit (4) to an actual value (I₁) of a motor encoder (8) or actual value (I₂) of a load sensor (9) of a second printing unit (4) is formed. Device according to one of claims 10 to 15, characterized in that the unit for generating the setpoint control signal (S) comprises a controller (13) and an associated frequency generator (12), the setpoint input signal generated by the frequency generator (12) (V) a signal is modulated on by the controller (13) to form the setpoint control signal (S), which signal represents a difference signal which consists of an actual value (I₁) of a motor encoder (8) or an actual value (I₂) of a load encoder (9) a printing unit (4) for the setpoint signal (V) is formed. Device according to one of claims 10 to 16, characterized in that the Motor controllers (10) are fed a setpoint signal (V) from a frequency generator (12) via a line (14) and a correction signal (K) from a machine control (13) via a further line (16). Apparatus according to claim 17, characterized in that the motor controllers (10) each have an address decoder (10.1) to which the correction signal (K) is fed and a setpoint / actual value comparator (10.2) to which the setpoint specification signal (V) and the correction signal (K) for forming the setpoint control signal (S) are supplied via the address decoder (10.1). Rotary printing machine, characterized by a device according to one of claims 10 to 18. Rotary printing machine according to claim 19, characterized in that only actual value signals (I₁, I₂) from actual value transmitters (8, 9) of one or more cylinders, in particular mechanically coupled cylinder pairs, each driven by at least one motor (7), of printing units (4) or their drive motors (7) are returned. Rotary printing machine according to claim 20, characterized in that other printing press components, in particular the web guiding components (2, 3, 5, 16), have, in addition to the motor controller (10), an advance multiplier (11) which is used by the controller (13) to ensure a sufficient web tension. advance signals are applied via a further control line (15).

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