EP0061596B2 - Printing machine with adjusting motors - Google Patents

Abstract

A printing press, in particular an offset printing press comprising a plurality of individually operable setting motors, in particular for adjusting the inkfilm density profile, each setting motor being connected to a pick-up generating electric signals characteristic of the actual position of the setting motor at any given moment (actual values) comprises an electronic comparator arrangement (35, 44) which is supplied with the actual values and, in addition, desired values for the position of the individual setting motors (9) and which repeatedly scans the actual values sequentially in a cyclical time sequence and compares each actual value with the related desired value to form a setting signal for operation of the associated setting motor in the forward or reverse direction when a given positive or negative minimum deviation is exceeded. The setting signals are fed to a switching arrangement (52) designed to cause the respective setting motor to be stopped or driven at a pre-determined speed in the sense of rotation determined by the last setting signal until the next signal is received. Thus it is rendered possible to easily control a plurality of setting motors.

Description

The invention relates to a printing press according to Preamble of claim 1. Such Printing machine is known from DE-A-24 01 750.

In the known printing press Comparison device when an adjustment process should cause the deviation between the target values and the respective actual values and saves the determined differences in a respective motor assigned Counter. While the servomotors are running are the individual counters by off voltage pulses obtained from an alternating voltage counted down and as soon as they hit the Have reached 0, the assigned one Actuator switched off. Will later Prompted a new actuation process, so the comparison device samples the actual values again cyclically, sets the counters again, and causes the Servomotors.

The number of times required in a press Actuators can be very large. So are the applicant's offset printing machine with a single inking unit 32 eccentric rotatable positioning cylinders for adjustment the color layer thickness profile in one Row arranged side by side. With a machine for multi-color printing with 6 printing units 192 servomotors for adjustment of the different color layer thickness profiles of different printing inks required.

It is a process by DE-C-1 231 339 for automatic register control, in particular known for multi-color rotary printing machines, when there is a register error exceeds a predetermined threshold, a memory level is set which outputs an adjustment pulse for the servomotor. The memory level is not based on that a subsequent measurement reset, but when the the register deviation determining counters by a preselectable frequency has been counted down. Therefore, the Actuator have already been switched off before the next scan is made.

US-A-3 930 447 describes a control device for densitometer measuring heads above of printed sheets of paper to be measured laterally adjustable by means of servomotors are. The target position is from a Computer entered in a register, and the Register content is controlled by a digital-to-analog converter converted to an analog size, which are fed to an input of a comparator becomes. The output of the comparator controls the Servomotor. The actual position of the actuator is tapped via a potentiometer and one other input of the comparator supplied. For each of the measuring heads is such an arrangement intended.

US-A-4 193 345 is an adjustment device for the color layer thickness profile known a printing press in which the individual Servomotors with potentiometers Actual value encoders are connected. Of the The potentiometer wiper is with an input connected to a comparator, and the Grinder is also a scanning and Holding circuit with the other input of the same Comparator connected. The output signal of the comparator controls the servomotor. The End connections of the potentiometer are on one adjustable voltage source to go on this Wise environmental influences, for example influences the temperature to the viscosity of the Printing ink, by changing the supply voltage of the potentiometer to be able to. The before a change of Supply voltage existing voltage on the grinder is in the sample and hold circuit stored, then the supply voltage changed, and the servomotor now runs until the tension on the grinder original grinder tension value has reached again. The arrangement described is intended for each individual servomotor.

The invention has for its object a Machine of the type described above with relatively simple means so that the Servomotors the given for them Reach target positions automatically.

This object is achieved according to the invention those specified in the characterizing part of claim 1 Features resolved. Here is the time interval between two consecutive Samples of the same sensor by the comparison device so short that the angle of rotation the servomotor including its stopping distance, which he puts back after switching off, at most equal to half the tolerance angle is the angle at which the actual position of the engine from the theoretical Target position in both directions of rotation may differ so that this deviation for the application in question as is considered admissible. If this scanning speed under consideration of Engine speed is correctly measured the engine when it is at a Sampling of the actual value is within the tolerance range, also always within the tolerance range for standing. The motor can therefore exceed the tolerance range not overflowing, and therefore there is the advantage that a possibly repeated reversal the direction of rotation of the motor until it reaches its Has reached the target position is not necessary. Another advantage is that the comparison device can be constructed very simply because it not the size of each scan existing deviation of the actual position of the Motor must determine from its target position, but only whether the engine is inside or outside the tolerance range described above is located, and it is for this reason too no need to collect and collect data transfer that the size of this deviation represent, but only the above Data, namely the control signals for forward running, Reverse run and standstill. The invention can also for setting the moisture layer thickness, e.g. B. by means of actuating cylinders, are used as well to adjust the color lifter. In the case of the invention Machine can also be a Manual control can be provided, as initially mentioned was described. During the setting process can servomotors that are different Printing units are assigned at the same time to run.

So that the servomotor is switched off with the smallest possible delay, are expediently those of the comparison device determined control signals immediately fed to the switching device.

In one embodiment of the invention is in the switching device, each servomotor an electronic Memory for storing the control signal assigned. That the control signal three different Can take values is enough a single flip-flop for this and therefore are for everyone in the later embodiment Memory provided two flip-flops.

The comparison device can with each one Actuator associated switching device each be directly connected in one embodiment the invention is however seen before that the comparator with each Control signal generates an address signal that the sampled actuator is assigned that the address signal of an address decoding circuit is supplied, which the control signal addressed Memory of the corresponding servomotor is assigned to save. This Embodiment particularly allows for large number of servomotors, as in the printing machines described above available are relatively easy Circuit technology.

For changing the direction of rotation of DC motors it is known per se to be in this Half-bridge circuit or full-bridge circuit to switch. In the first case it is one Connection of the anchor always with a fixed Potential to be called mass connected, and the other connection depends on the desired direction of rotation on a positive or negative potential. In the case of full bridge switching the two connections of the armature to different polarities placed, and to change the direction of rotation the polarity of both connections is reversed.

To use one and the same electronic Circuit of optional servomotors in half-bridge circuit or in full bridge circuit To be able to operate is in one embodiment the invention provided that the address decoding circuit depending on one of her supplied, two possible operating modes (half-bridge switching, Full bridge circuit) representing Mode signal is switchable, such that in one operating mode (half-bridge circuit) one address at a time Memory is allocated, and at the other Operating mode (full bridge circuit) of an address two memories are assigned, which are then such Store signals that for forward and Reverse the relevant servomotor to his Anchor clamps with different ones Potentials is supplied. In general this mode signal is unique to the manufacturer fixed and can therefore by a fixed applied potential are formed. It is the arrangement expediently made so that this mode signal the address decoding circuit only for a small one at a time Number of outputs of the switching device specifies a certain type of decoding, for example for only two outputs (here can choose between two half-bridge circuits or realized a full bridge circuit ) or for four outputs (here are optional four half-bridge circuits or two Full bridge circuits possible). It is possible, in a printing machine servomotors partly in Full bridge circuit, partly in half bridge circuit to operate.

In one embodiment of the invention the comparison device an analog Comparator for comparing the target values and Actual values. In another embodiment contains the comparison device for this Purpose a digital comparator; this can essentially formed by a subtractor be.

In one embodiment of the invention a brake logic circuit is provided, the Presence of the control signal for standstill Control signal for a connected power level generated with switches in full bridge circuit, the two with the same pole of the motor supply voltage source connected Control switches. This can lead to a long run-on of the servomotor, which also depends on variables that are difficult to determine and therefore only be calculated inaccurately can be prevented where necessary. This braking device can be dependent switchable from the above-mentioned mode signal be so that as in the later Embodiment only the braking device is effective with a full bridge circuit.

The servomotors for one described above Printing press need a current that per Actuator can be approximately up to 0.5 A. Did you want the above mentioned z. B. 192 servomotors Allow all to start at the same time for this in the case of the parallel connection in question such a large total current is required be that the required Power supply unit uneconomically large and would be expensive, especially considering the running time of the servomotors of just a few Hours a year. The one described above known printing press run in general only a few of the servomotors at the same time.

To the total current required by the servomotors is therefore to be kept at a minimum Embodiment of the invention one behind the Control device arranged in memory is provided, which drive the electrical energy the servomotors only one at a time of several predetermined groups of servomotors for a predetermined period of time feeds.

This could be done in such a way that with a predetermined number, for example eight servomotors of the above 192 servomotors, the drive energy is available for so long is set until the setting process is finished, that then the next eight servomotors be supplied, etc. If desired is that between the actuation of the first Actuator and that of the last actuator one less time passes than it has just described Use case passes, it is also possible, for example each of the above Groups of eight motors each, for example Power for 0.5 s and then the next group and stuff away. It would also be possible for the time when the Actuators in a group each with energy be provided to make it significantly shorter, especially shorter than the time between two successive scans one Donor. Such a relatively fast keying the energy supply can then be useful prove when at a particular Printing machine in relation to the servomotors to the scanning speed of the comparison device run too fast so it is desirable reduce their speed without doing that torque applied by the servomotors reduce significantly. This last also described Operating mode is considered to be under that in Described invention claim 1 falling, because this timing of the energy supply, does not affect the reliable Operation of the invention, in particular Phase position of the clocking of the energy supply relative to the sampling of the actual values of the individual Actuators have no influence on the Functional reliability of the machine according to the invention.

In one embodiment of the invention, the especially in connection with the just described control device can be realized can, and this in particular with the just described choice of different sizes Speeds of the actuators can be realized can, but need not be, it is provided that the comparison device for determining the Exceeding several different sizes Minimum deviations are formed by the actual values and that a switching device is provided is at the beginning of a setting process predetermined servomotors with a first predetermined Speed runs, this Actuators when falling below a first Minimum deviation are stopped and that the switching device then this Actuators with one compared to the first Speed runs lower speed and the Comparison device on a compared to the first minimum deviation smaller Minimum deviation switches. It takes place here First a rough setting of the servomotors with a corresponding to the relatively high speed large tolerance range (Minimum deviation) instead, and then can then because of the reduced speed of the Motors selected the minimum deviation smaller with this fine adjustment then the servomotors into the desired one Position. The advantage lies here in that in particular when starting for the first time Adjustment of all servomotors of the machine the adjustment process compared to such embodiments can be accelerated at which the actuators with only one Speed can run. The order can in the simplest case be such that switching the servomotors to the reduced one Speed only takes place when all Servomotors that increased with the above Speed can run when falling below the first minimum deviation has been stopped are. In general, it should be useful at least all those actuators that one have relatively large adjustment range in the described with different Read speeds. It can be convenient the arrangement must be such that not all actuators at the same time with the increased Speed, but only for example 16 servomotors each, so that the Power consumption from a power supply device remains limited to relatively low values, such as this has already been explained above. The diminished Speed can be described by the above Clocking can be effected.

Despite the principle of the invention, which is quite simple in principle Arrangement is for control of, for example, 256 servomotors for which the Circuit be expediently designed can, quite a considerable amount of logic circuitry required to control signals to switch through the individual servomotors.

Here, on the one hand, the number of components and thus the number of printed circuit boards connections to be made as small as possible and thereby keep the susceptibility to faults low, is according to an embodiment of the invention provided that the switching device contains at least one integrated circuit, which has: Depending on the control signals controllable power levels for connection of at least two servomotors, at least an address input for addressing the Power levels, at least one data input for the control signals and at least one Storage device for each power level Save the control signals. Preferably points the integrated circuit power levels for Connection of a total of four servomotors in Half bridge circuit or two servomotors in Full bridge circuit on; this embodiment can take into account the conventional housings for integrated Circuits existing external connections and the power loss without difficulty realize. Even for the integrated Protection alone is claimed for the circuit.

The integrated circuit is advantageous in bipolar technology, e.g. B. I ² L, or MOS technology. These techniques allow logic circuits and power stages to be implemented on the same die.

Further characterized in the claims Embodiments of the invention provide one Possibility to effectively brake the Servomotors and an adjustment of the control level of the power levels to those in the logical Circuit occurring signal level.

Figur 1 eine vereinfachte schematische Darstellung einer erfindungsgemäßen Druckmaschine,

Figur 2 ein schematische Darstellung eines mit einem Stellzylinder gekoppelten Stellmotors,

Figur 3 ein Prinzipschaltbild der gesamten Schaltungsanordnung für die Abtastung der Ist-Werte und die Steuerung der Stellmotoren.

Figur 4 das Logikschaltbild einer in Fig. 3 verwendeten integrierten Schaltung,

Figur 5 schematisch den Anschluß von vier Stellmotoren in Halbbrückenschaltung an eine integrierte Schaltung nach Fig. 4,

Figur 6 schematisch den Anschluß von zwei Stellmotoren in Vollbrückenschaltung an eine integrierte Schaltung nach Fig. 4,

Figur 7 eine Vollbrückenschaltung,

Figur 8 ein Prinzipschaltbild einer Schaltungsanordnung, die zu Fig. 3 eine digitale Vergleichseinrichtung aufweist.

Embodiments of the invention are described and explained below with reference to the drawing. Show it :

FIG. 1 shows a simplified schematic illustration of a printing press according to the invention,

FIG. 2 shows a schematic illustration of a servomotor coupled to an actuating cylinder,

Figure 3 is a schematic diagram of the entire circuit arrangement for the sampling of the actual values and the control of the servomotors.

FIG. 4 shows the logic circuit diagram of an integrated circuit used in FIG. 3,

5 shows schematically the connection of four servomotors in a half-bridge circuit to an integrated circuit according to FIG. 4,

6 shows schematically the connection of two servomotors in full bridge circuit to an integrated circuit according to FIG. 4,

FIG. 7 a full bridge circuit,

FIG. 8 shows a basic circuit diagram of a circuit arrangement which has a digital comparison device for FIG. 3.

Fig. 1 shows partially in a side view canceled an offset printing machine 1 with eight printing units, with five of the printing units are not visible. In one of the visible in Fig. 1 Machine parts are some parts of a printing unit 8 shown. The printing unit has one Plate cylinder 2 on which carries the printing plate and cooperates with the blanket cylinder 3, which the printing ink on the to be printed Paper transfers that between the blanket cylinder 3 and an impression cylinder 4 passes through. From the associated inking unit is only the ink metering box 5 with duct 6 is visible. At the bottom of the paint dosing box 5 there is a split color knife 7 that a series of actuating cylinders 15 (Fig. 2), each of which is connected to a servomotor 9 is. The printing unit 8 is also a Dampening unit 11 assigned to a water tank 12 has. Numerous other facilities especially rollers for transporting the Printing ink and water as well as transport rollers are not shown for the sake of simplicity.

Fig. 2 shows the adjustment mechanism simplified for one of the actuating cylinders 15 of the divided Color knife. The trained as a DC motor Actuator 9 drives a shaft 16 with which is coupled to a potentiometer 17. The wave 16 carries a threaded end Section 18, on which an adjusting piece 19th is screwed out, which is via a handlebar 20th with a rigidly connected to the actuating cylinder 15 Lever 21 is connected. The lower Bottom of the ink metering box 5 is through a Plastic film 22 formed, and depending on the position of the eccentric twist 14 Actuating cylinder 15 becomes this plastic film 22 more or less close to the outer surface of the ductor 6 and thereby one more or less thick gap 23 formed, through which the color to the bottom of the Can reach roller. The color then of other rollers of the inking unit in not removed in more detail shown. The adjustment of the actuating cylinder 15 thus takes place through a displacement of the adjusting piece 19 as a result a rotary movement of the servomotor 9. Two of the electrical connections of the potentiometer 17 are led to a voltage source, the Grinder of the potentiometer 17 is over a third line led out. The potentiometer 17 thus allows the respective position of the Actuating cylinder 15 to measure electrically. Each of the printing units of the printing press 1 are Assigned 32 actuating cylinders 15, the machine 1 therefore has a total of 256 actuators and same number of servomotors 9.

3 of the 256 potentiometers are 17th only two are shown. In the top one is mechanical actuation by the servomotor 9 indicated by a dashed connection. Each of the potentiometers 17 has an actual value for the position of the servomotor 9 and thus the Actuating cylinder 15 provides a potentiometer 30 assigned, the one lying on the grinder Voltage the setpoint of the position of the servomotor 9 represents. The wiper of the potentiometer In the simplest case, 30 is adjustable by hand. Instead of a potentiometer 30 can any other adjustable memory for Voltage values are used, in particular also a digital memory for digital values of the Voltage that a digital-to-analog converter is connected downstream, at the output of which the stored digital value corresponding DC voltage is produced.

An eight-digit binary counter 35 is provided, whose count input from a clock 36 Pulses are supplied at regular intervals will. The appears at the outputs 37 each counter reading as a binary number. There are 256 different meter readings possible. The Andes Outputs 37 appearing binary number forms one Address for each potentiometer 17. It is a first decoding circuit 38 is provided, the Inputs connected to the outputs 37 are. The first decoding circuit 38 has 256 Exits. Each of the associated Pairs of a potentiometer 17 and a switch 40 is assigned to a potentiometer 30, the one with exactly one output line first decoding circuit 38 is connected. Of the in Fig. 3 upper switch 40 is with that Output of the first decoding circuit 38 connected, who accepts a predetermined potential if the counter 35 the counter reading 255 3 shows the lowest switch 40 in FIG connected to the output that said Potential when counter 35 shows the counter reading 0. Only one of the Outputs of the first decoding circuit 38 has this called potential, and this causes a two-pole switching of the switch 40, so that the grinder of the associated potentiometer 17 is connected to a line 42 and the grinder of the assigned potentiometer 30 is connected to a line 43. These lines 42 and 43 are with the signal inputs a comparator circuit 44, the white individual comparators 45 and 46 contains, each then a positive, the output signal representing logical value 1 give up if that's your bottom at the signal fed to the left input higher than that of their upper left signal fed to the input. The ones from Grinder of the potentiometer 30 on the line 43 supplied voltage, which is the exact setpoint the rotational position of the assigned servomotor 9 is represented by an adjustable Resistance 47, the other end of which is more positive There is tension, somewhat increased, this Voltage increase in the permissible deviation the rotational position of the servomotor 9 from the setpoint corresponds upwards. This raised Voltage value is the upper input of the Comparator 45 supplied. The lower entrance of the comparator 46 becomes a voltage value fed by an adjustable resistor 48, the one connected to ground Resistor 49 forms a voltage divider, opposite the top input of the comparator 45 supplied voltage value by one The amount is reduced by twice the deviation the rotational position of the servomotor 9 from Corresponds to the setpoint. The line 42 is connected to the lower input of the comparator 45 and the upper input of the comparator 46 connected. Therefore appears at the output of the comparator 45 a positive signal when the voltage on the Line 42 is greater than a voltage that the Setpoint of this voltage plus the through the resistance 47 corresponds to the tolerance set, and at the output of the comparator 46 a positive signal appears when the Voltage on line 42 is lower than that Target voltage reduced by the permissible deviation from the setpoint. In all other cases are the output voltages of the comparators 45 and 46 0 V.

The six most significant outputs of the Counter 35 are a second decoding circuit 50 supplied with 64 outputs, each only one of these outputs has a low potential Dependence on the counter reading of the counter 35 assumes that as a chip selection signal to choose from one of 64 integrated circuits 52 is used. The two least significant outputs of the Counter 35 are two address inputs of each of the Integrated circuits 52 supplied. The exits of comparators 45 and 46 are also via lines 51 and 53 two each Data inputs from each integrated circuit 52 fed. Each integrated circuit 52 has four outputs to connect four Actuators 9 in half-bridge circuit or of two servomotors 9 in full bridge circuit allow.

4, the logic diagram of the integrated circuit 52 is shown. It contains inverters, AND gates, NAND gates, NOR gates and flip-flops, which are represented by the known symbols, and also four power stages 56 to 59, which are each of the same design. All connections for the operation of the logic circuits are shown on the left edge of FIG. 4. A reset input R is used to reset all flip-flops when the power supply for the illustrated electronic circuits is switched on, in order to ensure defined output states. The inputs A0 and A1 are supplied with the address signals supplied by the two least significant outputs of the counter 35. There are two negated chip select inputs CS1 and CS2 intended ; one of these inputs is connected to exactly one of the outputs of the second decoding circuit 50, the other of these two inputs is set to 0 V. The condition is therefore when a chip selection signal with low potential (ground) occurs CS1 = 0 is fulfilled and the addresses supplied to inputs A0 and A1 can be evaluated. Having two chip select inputs can often simplify addressing. Two further connections (U, GND) are provided for the voltage supply of the logic circuit. An entrance FZ / RE is used to switch between half-bridge and full-bridge circuits. If this input is connected to ground, i.e. logic 0, four servomotors can be connected to the output stages 56 to 59 in half-bridge circuit, the input is connected FZ / RE to a positive voltage of 5 volts in the example, so one can be connected to the output stage pairs 56 and 57 on the one side and 58 and 59 on the other hand each a servomotor in full bridge circuit.

The data inputs D + and D - The control signals appearing on lines 51 and 53, which can also assume the logical values 0 and 1, are supplied. Two equal entrances P and SP make it possible to lock the output stages 56 to 59 without influencing the memories, e.g. B. for pulse operation.

Connections are at the bottom on the right edge of FIG. 4 for a positive and negative supply voltage for those to be connected Servomotors shown, in the embodiment these are the voltages of + 15 V and - 15 V. The power levels 56 to 59 each have two outputs, the upper one the positive supply voltage of + 15 V and the lower one is the negative supply voltage - 15 V to a connected servomotor can optionally switch through.

The integrated circuit 52 contains several functional units. An operating mode-dependent pressure decoding 60 is provided which, depending on whether the integrated circuit 52 is switched to a half-bridge circuit or a full-bridge circuit, either assigns exactly one of the power stages 56 to 59 to a specific address supplied to the terminals A0 and A1 or one of the pairs 56, 57 or 58, 59 of the power levels. A data interlock 61 ensures that only one of its two outputs can assume the value logic 1, or that both outputs have the value logic 0. The data interlock 61 provides security against interference in the event that the logic 1 signal occurs simultaneously on the lines 51 and 53 for some reason. An operating mode-dependent data decoding 62 carries the data, namely the control signals, depending on whether the integrated circuit 52 is switched to a half-bridge circuit or a full-bridge circuit, in each case only to the memory assigned to a single power stage or to a pair of power stages 56, 57 or 58, 59 assigned memories. The eight flip-flops 54, 55 provided are combined to form a memory unit 63 by a dashed frame. Two of the flip-flops are assigned to a power amplifier, this is also indicated by dashed lines. Each of the flip-flops 54, 55 has a clock input T, a reset input R , a data input D and a non-inverting and inverting output Q or Q on. The flip-flops 54, 55 are clock-controlled (latch) and store the information contained in them at the end of the clock pulse. During the application of the clock pulse, the memory content follows the input signal.

A functional unit pulse signal processing 64 evaluates this at the inputs P and SP supplied input signal to block the power stages 56 to 59 in accordance with these signals. This pulse signal processing 64 is connected downstream of the memory unit 63 and effects a mutual locking of the output signals of the two flip-flops 54 and 55 assigned to an output stage for forward or reverse running of the respectively connected servomotor, the connections of the armature of the servomotor are at the same potential, in the example - 15 V. As a result, the armature of the servomotor is short-circuited and is therefore braked very quickly. If the armature is already at a standstill, undesired twisting of the armature, for example as a result of vibrations, is prevented.

The logic elements connected downstream of each pair of flip-flops 54 and 55, each of which together form a memory assigned to exactly one power level, and which are part of the pulse signal processing 64 and the operating mode-dependent braking logic 65, are connected in the same way in all cases. These are three NAND gates 91, 92, 93, a NOT gate 94 and an AND gate 95. The output of the NOT gate 94 is in each case connected to the upper input of the assigned power stage 56 to 59, that is to say the input E1 +, E2 + etc. connected. The output of the element 95 is connected to the other input of the power stage. The input of link 94 is connected to the output of link 91. One input of link 95 is connected to the output of link 93, the other input to the output of link 92. The inputs of link 93 are to the outputs of links 91 and 92 and to the input FZ / RE of the integrated circuit 52 connected. The inputs of the gate 91 are connected on the one hand to the output of a NOR gate 96, the inputs of which are connected to the control inputs P and SP of the integrated circuit 52 are connected, the further inputs of the element 91 are connected to the non-inverting output of the flip-flop 54 and the inverting output of the flip-flop 55. One input of the link 92 is again connected to the output of the link 96, the other two inputs are connected to the inverting output of the flip-flop 54 and the non-inverting output of the flip-flop 55.

The braking logic 65, which is defined by the links 93, 94 and 95 is formed, ensures that in one Memory content of the flip-flops 54 and 55 with the logical values 0; 0 with half-bridge connection at the inputs of the assigned Power levels 56 to 59 the signals 0; 1 and the two outputs M + and M- this power level are switched off, whereas with full bridge switching at same memory content 0; 0 at the inputs of the two assigned to each other Power levels, for example 56 and 57, everywhere the logic level is 0, so that in both Power levels of the output M- on the negative motor supply voltage, thus an electrical braking of the Motor is possible.

In the case of half-bridge circuits, the following are Combinations of the connections A1, A0 supplied address signals each behind assigned to specified performance levels : 0; 0 to 56, 0; 1 in 57, 1; 0 to 58, 1; 1 in 59.

With full bridge switching, the following are address signals supplied to the inputs A1, A0 the pairs of Power levels assigned: 0; 0 to 56 and 57, 1 ; 1 to 58 and 59. With hard wiring is therefore only a single address line is required.

For the following combinations of data inputs D + and D - Control signals supplied are indicated in each case whether they result in a standstill of the motor connected to the respectively addressed power stage or the addressed power stage pair, or cause a forward or backward run. The direction of rotation of the motor which results when the respective power stage supplies a positive voltage to the motor in the case of a half-bridge circuit should be defined as the forward run, and should be defined as a forward run in the case of a full-bridge circuit when the upper of the two power stages in FIG. to which the motor is connected supplies positive voltage to it. The information applies to full and half bridge switching. 0; 1 for forward run 1; 0 for reverse running; 0; 0 for standstill.

5 shows in a simplified manner how four servomotors 9 can be connected in a half-bridge circuit to an integrated circuit 52. The two outputs of each power stage 56, 57, 58, 59, which are designated M1 +, M1- for example at power stage 56, are connected to one another, and a servomotor 9 is switched on between the connection point and ground. The two outputs belonging to each of the power stages 56 to 59 could also be connected to one another within the integrated circuit 52. However, they are brought out so that a servomotor that is only operated in one direction of rotation or another consumer can be connected to each of the outputs if required. However, it is then advisable to ensure that the two outputs can be controlled independently of one another. 5 is the logic input FZ / RE connected to ground, is therefore a logical 0.

6, the logic input is located FZ / RE on + 5 V, this voltage value represents the logic level 1. The two outputs belonging to one of the output stages 56 to 59 are in turn connected to one another and a servomotor 9 is connected between the common outputs of the power stages 56 and 57, another servomotor 9 between the interconnected outputs of power level 58 and power level 59.

Fig. 7 shows the circuit diagram of an embodiment of power levels that a full bridge circuit form. These performance levels can the power levels of the integrated Form circuit 52, with in individual cases the integrated circuit technology changes may be required. Hereinafter it is assumed that the two power levels 56 and 57 of the integrated circuit Fig. 4 are shown in Fig. 7, and therefore are 7 also the same designations for the Signal inputs E1 +, E2 +, E2- and the outputs M1 +, M1-, M2 +, M2- used. Other connections in Fig. 7 are the connections for the positive and negative supply voltage for the motor and the positive supply voltage for the logic (+ 5 V) and the ground connection for logic (GND).

The circuit diagram for power level 57 is correct completely in line with that for performance level 56, the corresponding components are each equal. A pnp power transistor 70 is with its emitter on the positive motor supply voltage connected with his Collector at output M1 +. An NPN power transistor 71 is at the exit with its collector M1- connected and with its emitter on negative pole of the motor supply voltage. Both collector-emitter lines are through each bridges a diode 72 that is opposite for the polarity of the respective base-emitter diode connected. These diodes 72 serve to protect transistors 70 and 71. At there is a connection to each transistor 70, 71 between the base connection and emitter connection via a resistor 75 or 76, the are the same size. At the base of transistor 70 the collector of an npn transistor 78 is connected, its emitter via a resistor 79 with the connection for the ground potential of the Logic (GND) is connected. This connection is via a voltage source 80 with the base of the Transistor 78 connected, which also via a resistor 81 connected to the terminal E1 + is. The voltage source 80 is in Example of a series connection of four Diodes formed.

The base of transistor 71 is with the Collector of a pnp transistor 84 connected, whose emitter via a resistor 85 with the Connection for the positive supply voltage for the logic connected to the base of the Transistor 84 through a voltage source 86 is also connected by a series connection is formed by four diodes. The Diodes of voltage sources 80 and 86 are poled in the same direction as that Base-emitter diode of the assigned Transistor. These diodes 80 and 86 hold in Connection with resistors 81 and 82, respectively Base voltage of transistors 78 and 84 too with values of E1 +, E1-, if this z. B. Values up to + 10 V. assume, almost constant and effect thereby limiting the base current and thus a limitation of the power loss of the Transistors 78 and 84. The base of the transistor 84 is connected through a resistor 82 to the terminal E1- connected. The on the input terminals E1 + and E1- as well as E2 + and E2- occurring Signals, the output signals of the operating mode-dependent brake logic 65, can the levels + 5 V and 0 V related to Accept logic mass. Be the two logic inputs E1 + and E1- the same input signals logically 0, i.e. 0 V supplied, see above 7 is the top power transistor 70 blocked and the lower power transistor 71st the power level 56 switched through, the connection point between the outputs M1 + and M1- is therefore due to the negative motor supply voltage from - 15 V. Will the both inputs E1 + and E1- the signal logically 1 supplied, i.e. a voltage of + 5 V, so the transistor 70 is turned on and the Transistor 71 blocked and the connection point of outputs M1 + and M1- is at + 15 V.

If the input E1 + becomes a voltage of 0 V fed and the input E1- a voltage of + 5 V, the outputs are M1 + and M1- voltage-free, since both transistors 70 and 71 are locked.

The state that the input E1 + a Voltage of + 5 V is supplied and the Input E1- a voltage of 0 V, is at the circuit shown, in which the two Transistors 70 and 71 directly with each other connected, inadmissible, because in this case the motor supply voltage is short-circuited would. This inadmissible state is determined by the pulse signal processing 64 caused locking prevented.

So that the servomotor 9 in Fig. 7 in the above defined forward direction is driven must the signal inputs E1 + and E1- Voltages + 5 V and the signal inputs E2 + and E2- the voltages 0 V are supplied. For reverse running are the ones just mentioned Swap voltage values.

So that the servomotor 9 stopped as quickly as possible will turn off the actuator 9 not all transistors 70 and 71 blocked at both power levels 56 and 57, but it is connected to the input terminals E1, E2 of the two power levels 56 each Voltage 0 V applied, so that on the two Armature connections of the servomotor 9, which with the Outputs of power levels 56 and 57 connected are the negative supply voltage lies, these two connections of the anchor are short-circuited. The armature winding creates hence a current that is generated when the servomotor 9 runs in the forward direction, which in FIG direction designated by reference numeral 89 Has. This current can cross the collector-emitter path flow through the transistor 71, since this is controlled at its base. At a usual dimensioning of the base voltage of the transistors 71 of the two power stages however, the current could not be transistor 71 flow through the power level 57 because it is this is an npn transistor. Of the In this case, current flows via the parallel this transistor switched diode 72. Da on this diode has a voltage of approximately 0.7 V to 1 V drops, an armature current flows in the motor 9 only until its terminal voltage below this the voltage value just mentioned drops, then the engine is no longer electric braked, but only by those of him too overcoming frictional forces.

According to the invention, however, the resistor 85 in both output stages 56 and 57 so small that the Transistor 84 to the base of transistor 71 provides a base current that is at least about 30 times as large as for normal switching operations of the transistor required. Thereby it becomes possible to reverse the transistor 71 too operate, this inverse operated Transistor just a voltage drop of about 50 to 100 mV. The servomotor 9 is hence to a much lower one Terminal voltage braked electrically and therefore comes to a standstill much faster as if the armature current during braking within performance level 57 only through the diode 72 could flow. In the case of FIG. 7 drawn direction of the armature current would be it is not necessary that the transistor 71 the performance level 56 with the mentioned high Base power is supplied, the dimensioning described the resistors 85 do it however superfluous to one of each If necessary, transistors 71 have a higher base voltage to switch on and thereby simplified the circuit. It goes without saying that the Arrangement could also make such that Braking the motor 9, the two transistors 71 are blocked and the two transistors 70 are controlled; the latter Transistors would then have to be in the described Way with compared to normal operation increased base current can be supplied. In the described However, the embodiment are Resistors 79 larger than resistors 85, see above that the transistors 70 only one from the emitter to the current flowing to the collector.

In the case of a special servomotor 9, this resulted when just turning off the power supply an expiry time of 3 seconds. Became this Motor on the circuit shown in Fig. 7 operated, but the transistors 71 are not could be operated inversely, so reduced the braking by means of the diode 72 Flow time to about 0.5 seconds. In the case of Fig. 7 finally shown, in which in the the transistors 71 described above run inversely, was the expiry time only 7.5 ms left.

In the circuit shown in Fig. 7 is still beneficial that, although compared to logic levels large positive and negative Has to switch voltages on one of their Control inputs has the level 0 V. Of the other control input gets depending on the circuit a positive or a negative potential for Switch through. In the example, the logic levels are 0 V and + 5 V are used. This advantage applies to each of the two power amplifiers 56 and 57 alone, the then each form a half-bridge circuit, if the one connecting the two output stages Servomotor 9 in Fig. 7 is removed. Then a servomotor between each Connection point of the connections M1 + and M1- and a fixed potential, especially mass, be switched on. The advantage with these Half-bridge circuits is that on their by connecting the connections M1 + and M1- formed circuit output optionally switched a positive or negative voltage can be.

Transistor 70 : BSV 16-16

Transistor 71 : BSX 46-16

Transistor 78 : BCY 59/X

Transistor 84 : BCY 79/VIII

Dioden 72 : 1 N 4003

Widerstand 81 : 2 kOhm

Widerstand 82 : 6,2 kOhm

Widerstände : 75, 76 : 82 kOhm

Widerstände: 79, 85 : 82 kOhm

Spannungsquellen 80, 86 : je 4 × Diode BAW 76

In the embodiment of FIG. 7, the following values apply to the individual components:

Transistor 70: BSV 16-16

Transistor 71: BSX 46-16

Transistor 78: BCY 59 / X

Transistor 84: BCY 79 / VIII

Diodes 72: 1 N 4003

Resistor 81: 2 kOhm

Resistor 82: 6.2 kOhm

Resistances: 75, 76: 82 kOhm

Resistances: 79, 85: 82 kOhm

Voltage sources 80, 86: 4 × BAW 76 diodes each

It is assumed that the described rapid braking of the servomotors 9 is not required in a printing machine for the ink zone control. These servomotors, which are used to adjust the ink layer thickness, can therefore be connected in a half-bridge circuit. A printing machine for multicolor printing also has setting devices by means of which an exact fit of the individual prints applied by the different printing units, each with a different color, is ensured. These adjustment devices are called registers. Since a very high setting accuracy is required here, it will generally be necessary to operate the servomotors that drive the registers in the manner described above in full bridge circuit in order to be able to brake these servomotors quickly. The terminals designation FZ / RE was chosen with regard to the terms color zone and register. The register is generally adjusted by the printer during the printing process, but can also be done automatically.

In the exemplary embodiment, the cycle time, that is to say the time period which is available for the detection of the actual values by the comparison device and the forwarding of the control signals up to the power levels, is approximately 50 μs. The servomotors 9 are via the pulse input P each operated in pulsed fashion, the current flow time in the motor in the exemplary embodiment being 30 ms and the pause between two pulses being 270 ms. Different groups of servomotors are supplied with the current pulses at different times from each other.

The time it takes an actuator to complete the to go through the entire adjustment range 8 seconds in the exemplary embodiment. The whole Adjustment range is divided into 256 intervals, that should be accessible individually. Each this interval or increment therefore has one Length of about 30 ms. During this time the electronic device described above Execute 600 queries of the actual values, together with the corresponding determination of the control signals. Because the one described above as an example Printing machine with eight printing units next to the Servomotors for ink zone adjustment yet about 24 additional actuators for the registers, a total of 280 servomotors are required thus with each servomotor within each of its individually approachable 256 increments two Interrogate. This results in great security against accidents that could occur as a result that one of the queries from any Reasons is disturbed.

Fig. 8 shows an overall circuit that instead the circuit arrangement shown in Fig. 3 can be provided and a digital comparison device having. The actual values will be also detected here by the potentiometer 17, from which only two are shown and one for the actual value 1 and one for the actual value 256. 64 are also integrated here Circuits 52 provided that additionally with the designations IS 1 (integrated Circuit 1) to IS 64 are designated. From these integrated circuits are shown in Fig. 8 only four are shown.

The analog signals generated by the potentiometers 17 an analog multiplexer for the actual values 120 fed. A binary counter 135, which is advanced by a clock generator 136 has 9 counters and just as many outputs 141 to 149. The eight most significant Outputs 142 to 149 signals appearing are used as address signals, these address inputs of the analog multiplexer 120 fed. The one through the current value selected in each case is an input from the analog multiplexer 120 an analog-to-digital converter 150, which this analog signal into a binary 8-bit information converts that in parallel to a group of inputs 152 of a binary comparator 151 be fed. The analog-digital converter 150 receives its start command to convert also from the lowest value output 141 of the Binary counter 135. Since the 141 appearing pulse repetition frequency twice is high, as the switching frequency of the at the Outputs 142 to 149 appearing addresses, ensures that between generation of two consecutive addresses of the Analog-digital converter 150 receives a start signal.

A second group 153 of inputs of the Binary comparison res 151 become digital target values fed from a digital setpoint memory, which also contains the address signals from the binary counter 135 are supplied and each one The setpoint is switched through to the binary comparator, which is currently from the analog multiplexer 120 connected actual value is assigned. The the inputs 156 of the setpoint memory 155 supplied digital target values can be with the help of an analog-digital converter made of analog Signals, for example from potentiometers delivered, generated. These target values can also by a keyboard or by a computer or from a data carrier where they are stored in binary form, in the Target value memory 155 can be entered.

The binary comparator 151 is a subtracting circuit. It always subtracts the signals fed to the inputs 152 from the signals fed to the inputs 153 when an output Data Ready of the analog-digital converter 150 outputs a signal to the binary comparator 151. Depending on the result of the subtraction, the binary comparator 151 then outputs an output 160 (if the signal at the inputs 152 was larger than at the inputs 153) or 161 (in the opposite case), assuming that the two values are the same must distinguish the minimum deviation described at the outset, or the binary comparator 151 does not output an output signal. Outputs 160 and 161 are with the data inputs D + and D - The integrated circuit 52 connected. The two least significant bits of the address present at the analog multiplexer are applied to the address inputs A0 and A1 of the integrated circuits 52 and thus cause a preselection of the output stages of the individual integrated circuits. The chip selection itself is carried out with the aid of a decoder 165 with 5 inputs and 32 outputs and with the aid of the most significant address bit. For this purpose, the 64 integrated circuits 52 are divided into two groups IS1 to IS32 and IS33 to IS64.

An integrated circuit of each group receives the CS 2 signal from decoder 165. One of the groups 1 to 32 or 33 to 64 is then selected by the most significant address bit, which in the first group is sent directly to the CS1 -Inputs and in the second group inverted by a NOT gate 170 to the CS 1 -Inputs is created. As a result, exactly one of the integrated circuits 52 is selected. The integrated circuits 52 in FIG. 8 are the same as described with reference to FIG. 4.

As far as details of the circuit, in particular 4, have not been described referred to the drawing.

Claims (19)

1. Printing machine, preferably offset printing machine (1), in which a plurality of individually switchable servo motors (9) is provided, preferably for adjusting the ink layer thickness profile, each servo motor (9) being connected to a transmitter (17) which generates electric signals (actual values) which are characteristic of the respective actual position of the servo motor (9), an electronic comparing device (35, 44) being provided which is supplied with the actual values and also with nominal values for the position of a servo motor (9) and which compares the actual value with the nominal value and, as a function of the result of the comparison, causes the servo motor (9) to run in the forward direction or to run in the reverse direction or to stand still, the comparing device (35, 44) being supplied with the actual values and nominal values of the individual servo motors (9) and the comparing device successively in time and cyclically repeatedly interrogating the actual values, characterised in that the comparing device (35, 44) repeatedly interrogates the actual values during an adjusting operation of a servo motor (9), that the comparing device (35, 44) generates servo signals for the forward motion or the reverse motion of the associated servo motor (9) if a predetermined positive or negative minimum deviation is exceeded and otherwise generates a servo signal for the standstill of this servo motor (9) and that the servo signals are supplied to a switching device (52) which is constructed in such a manner that the respective servo motor (9) is driven at a predetermined speed of rotation in the direction of rotation determined by the respectively last servo signal allocated to it, or remains stopped, until the next servo signal allocated to it arrives, and that in consideration of the rotational speed of the respective servo motor (9) the time length of the scanning cycle is rated such, that the motor also comes to a stop, when during scanning the motor is within the range of the predetermined minimum deviation.
2. Machine according to Claim 1, characterised in that in the switching device (52) each servo motor (9) is associated with an electronic memory (54, 55) for storing the servo signal.
3. Machine according to Claim 1 or 2, characterised in that the comparing device (35, 44, 135, 151) generates with each servo signal an address signal which is allocated to the servo motor (9) just sampled, and that the address signal is applied to an address decoding circuit (50, 60, 165) which supplies the servo signal to the memory (54, 55) associated with the corresponding servo motor (9).
4. Machine according to Claim 3, characterised in that the address decoding circuit (60) can be switched over as a function of an operating mode signal which is supplied to it and which represents two possible operating modes (half-bridge circuit, full-bridge circuit), in such a manner that in one operating mode (half-bridge circuit) an address is in each case allocated only one memory (54, 55) and in the other operating mode (full-bridge circuit) an address is allocated two memories (54, 55).
5. Machine according to one of Claims 1 to 4, characterised in that the comparing device (35, 44) is provided with an analog comparator (45, 46) for comparing the nominal values and actual values.
6. Machine according to one of Claims 1 to 4, characterised in that the comparing device (135, 151) is provided with a digital comparator (151) for comparing the nominal values and the actual values.
7. Machine according to one of the preceding Claims, characterised in that a braking logic circuit (65) is provided which, in the presence of the servo signal for standstill, generates a control signal for a connected power stage (56, 57) with switches (70, 71) in a full-bridge circuit, which signal renders conductive two switches connected to the same terminal of the motor supply voltage source.
8. Machine according to Claims 4 and 7, characterised in that the braking logic circuit (65) can be switched on by the operating mode signal for full-bridge circuit.
9. Machine according to one of Claims 2 to 8, characterised in that a control device is provided which is arranged following the memory (54, 55) and which supplies the electric energy for driving the servo motors successively in each case only to a part of the total number of the servo motors (9) during a predetermined period of time.
10. Machine according to one of the preceding Claims, characterised in that the comparing device is constructed for determining the fact that several minimum deviations of different magnitudes have been exceeded by the actual values and that a switch-over device is provided which at the beginning of an adjusting process lets predetermined servo motors (9) run at a first predetermined speed of rotation, these servo motors (9) being stopped if the actual value drops below a first minimum deviation and that the switch-over device subsequently causes these servo motors (9) to run at a speed of rotation which is smaller than the first speed of rotation and switches the comparing device to a minimum deviation which is smaller compared with the first minimum deviation.
11. Machine according to one of Claims 1 to 9, characterised in that the switching device contains at least one integrated circuit (52) which is provided on the same chip with at least one power stage (56, 57) for connecting a motor (9) and a control logic circuit (60 to 65) for controlling the power stage (56, 57).
12. Machine according to Claim 11, characterised in that the integrated circuit (52) is provided with the following : Power stages (56 to 59), which can be controlled as a function of the servo signals, for connecting at lest two servo motors (9), at least one address input for addressing the power stages (56, 57), at least one data input for the servo signals, and at least one memory device (54, 55) for each power stage (56, 57) for storing the servo signals.
13. Machine according to Claim 12, characterised in that the integrated circuit (52) is provided with power stages (56, 57) for connecting a total of four servo motors (9).
14. Machine according to one of the preceding Claims, characterised in that it is provided with a power stage (56, 57) for a servo motor (9), the power stage (56, 57) being provided with four transistors (70, 71) in a full-bridge circuit, the collector-emitter paths of which are connected, on the one hand, to the terminals of a supply voltage source and, on the other hand, to terminals for the armature of the servo motor (9) and that the base terminals of two transistors (70 and 71) connected to the same terminal of the supply voltage source are supplied at least during the braking of the motor (9) with a base current which makes it possible to operate the transistors in inverse mode.
15. Machine according to Claim 14, characterised in that the transistors provided for inverse operation are supplied, for conduction in normal operation for forward motion and reverse motion of the servo motor (9), with a base current the magnitude of which is identical to the base current for inverse operation.
16. Machine according to one of the preceding Claims, characterised in that it is provided with a power stage (56, 57) for a servo motor (9), which stage is provided with two controllable switches (70, 71) which selectively switch through a supply voltage, which is positive or negative with respect to a reference potential, to a circuit output or they are both blocked.
17. Machine according to Claim 16, characterised in that for controlling the switches (70, 71), two transistors (78, 84) are provided, that the emitter of one transistor (78) is connected to a first fixed potential and the base of this transistor can be supplied with a voltage, which is positive with respect to the fixed potential, as a control signal, and that the emitter of the other transistor (84) is connected to a second fixed potential, which is positive with respect to the first potential, and the base of the other transistor (84) can be supplied with a voltage, which is negative with respect to the second potential, as a control signal.
18. Machine according to Claim 17, characterised in that to the positive terminal of a supply voltage source for the servo motor (9) the emitter of a pnp transistor (70) is connected, the base of which is connected to the collector of an npn transistor (78) the base of which is coupled to a first control input and the emitter of which is coupled to a connection of a first fixed potential, that the emitter of an npn transistor (71) is connected to the negative terminal of the supply voltage source for the servo motor (9), that the base is connected to the collector of a pnp transistor (84) the base of which is coupled to a second control input and the emitter of which is coupled to a connection of a second fixed potential and that the collectors of the pnp transistor (70) and of the npn transistor (71) form the outputs of the power stage (56, 57).
19. Machine according to Claim 17 or 18, characterised in that voltages having the level of the first and second fixed potential are provided as control signals.

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