EP1149697A2 - Method and device for driving a printing press with two individual drives - Google Patents

Abstract

The method involves measuring the angular position of the wheel train at two different points, whereby the position of an individual drive (9,10) is set depending on the difference resulting from the angular settings. The measurement is made before the start of a printing process in a predetermined operating state and the drives are biased by the difference during printing. Independent claims are also included for the following: a drive for a printing machine.

Description

The invention relates to a method for operating a printing press, in particular a sheetfed offset printing machine in which two are independent operated, position-controllable individual drives in a continuous Feed the wheel train, whereby the subunits coupled to the wheel train the printing press are driven and a rotation of the gear train is generated between the input points of the individual drives and a drive to carry out the procedure.

In sheetfed offset presses, the cylinders of the printing units as well as the cylinders and drums used for sheet transport via one continuous gear train. In this train of wheels arise very high load moments, especially with a high number of printing units, which cause a torsion of the gear train between the individual printing units.

To reduce load-dependent printing errors in the printing press, according to the DE 42 10 988 A1 a device for controlling a multi-motor drive Printing machine known in which the printing machine has a continuous Gear train and several electromotive individual drives, which in the Feed the wheel train. At each power-feeding individual drive, the instantaneous position of the electric motor measured in the form of an angle of rotation and fed to a control device, which from the angle of rotation differences two neighboring motors in the power flow on their power flows closes. Depending on the determined angle of rotation difference, the Actuators of the electric motors are controlled such that the elastic Twist in the gear train of the drive of the printing press and thus also the Power flows are kept constant.

Despite the performance monitoring and evaluation of the individual drives, it can Because of the elasticity and inertia of the wheel train, it always takes off the tooth flanks of the gears inside the gear train come to what Registration errors and to duplicate the print image on the printable Fabric leads.

The invention is therefore based on the object, a method and a Specify device for operating a printing press, in which despite the rigid, angularly synchronous rotation at the entry points of the electromotive single drives a lifting of the tooth flanks of the Gear train is prevented safely.

According to the invention, the object is achieved in that the angle of rotation position of the gear train is measured at two positions of the gear train, the Location of a single drive depending on the resulting Difference resulting from the rotational angle positions is set.

The advantage of the invention is that the actual rotation in the The gear train of the printing press was measured and used to set a preload one of the individual drives compared to the second single drive is used. This ensures that all interlocking tooth flanks of the The gear wheels of the gear train just lie against each other and therefore always one minimal positive load is transferred to the gear train. An unnecessarily strong one Bracing the gears against each other is reliably avoided and a Increased wear in the gear transmission prevented.

In one embodiment, the rotational angle difference of the gear train before the start of the printing process depending on a predetermined operating state of the Printing machine determined and the individual drive during the printing process prestressed this angle of rotation difference.

After setting the predetermined operating state, the Printing machine the wheel train by the single drive in a predetermined Direction of rotation moves, the difference in the angular position within the Wheel train is determined by moving the wheel train until at multiple measurement a constant angle of rotation difference is determined.

With this initialization process, the Printing machine a constant angle difference depending on one certain load state of the printing machine is reached. The load state is thereby especially by the machine speed of the printing press, the color in the Characterized inking units and the printing state of the printing units. For every Load situation of the printing press is therefore simply a preload on the Individual drive can be determined.

In an advantageous development, the position of the position-controllable Single drive before the movement of the gear train and after reaching the constant angle of rotation difference of the individual drive determined, from the a rotational angle difference of the individual drive is determined in both positions, where from the sum of the rotational angle difference of the gear train and the Rotation angle difference of the individual drive, the bracing is determined in order which the single drive is preloaded during the printing process.

Due to the preload setting of the position-controllable single drive it comes as a result of the elasticity of the gear train and the present Tolerances for a defined tension of the wheel train, at which the Backlash of the gear train is withdrawn at every angular position.

The accuracy of the twist presetting of the wheel train is improved, if an additional angle of rotation difference is set, which consists of a predetermined operating load and / or the wheel stiffness is determined.

In another development of the invention, two can be acted upon individually Single drives connected to a control unit, the individual drives on two different places of the printing press in one continuous Feed the wheel train, which is coupled to the subunits of the printing press is, a position-controllable individual drive by the control unit with a Setpoint can be acted upon, causing the gear train between the two Individual drives can be preloaded by a predetermined angle. to Improvement of the tooth flank system of the gear wheels of the gear train are on two different positions within the gear train arranged, which are connected to the control unit and the angular position of the Signals in these positions to the control unit deliver which, depending on these angular positions, a position setpoint determines with which a single drive during the printing process is acted upon.

In one embodiment, particularly precise results are obtained via the Rotation of the gear train achieved when the angular position of two in Gear train of adjacent gears is detected, each Position sensor emits a signal per gear revolution, from which the Control unit a rotation angle difference under specified operating conditions calculated.

The play of the tooth flanks of the gears is surely prevented when the Control unit applies a setpoint to the individual drive, which is derived from the Rotational angle difference of the gear train and a rotational angle difference of the Individual drive can be determined.

This procedure makes it possible for all components of the Printing press can only be fed by two individual drives, each Single drive via the gear train a predetermined number of subunits Printing machine drives.

According to one embodiment of the invention it is provided that each drive for an electric motor has its own independent speed control loop. These speed control loops are given identical basic speed setpoints fed. With the exception of a master drive, each slave drive receives one Another setpoint, the additional speed setpoint, which is generated by the slave drive assigned differential angle controller is formed.

The actual value of each of these differential angle controllers can be derived from the actual angles of the concerned slave drive and an adjacent slave drive Difference or that from the actual angles of the slave drive concerned and the Lead drive formed difference are used. The master drive must not necessarily be adjacent to the slave drive under consideration. alternative the difference between the actual angles can also be calculated using a difference of Actual speeds of two drives with subsequent integration to determine one Difference angle can be realized. The actual speeds can also be selected here of the relevant and a neighboring slave drive or the relevant one Slave drive and the master drive can be used to form the difference.

If necessary, the control concept can include a power or Torque pre-control in each or only in individual control loops be expanded. To do this, the differential angle controller is converted from the manipulated variables Pilot control currents or torques are calculated. These input tax parameters are as additional setpoints the current or torque controllers of the respective Slave drives activated.

The basis for recording the actual values (actual angle and / or actual speed) are Absolute encoder (angle encoder) or incremental encoder with Reference signal for determining the absolute position.

To determine fixed values for the setpoint specification for the Differential angle controllers can be in different positions in the gear train at least two sensors can be arranged, which are dependent on variable Operating states of the printing press (e.g. depending on speed, temperature etc.) provide angle information. With the help of a variety of temporarily varied Target differential angles can be used as basic values for setting the differential angle individual drive axles determined relative to each other and as static Setpoint specification can be stored in the differential angle controllers.

The determination of a setpoint specification for the differential angle controller can also be based on Based on other different basics, e.g. E.g .: by more fixed values or by any movement size (Angular velocities or accelerations) or by force quantities (Drive and cutting torques) or by electrical quantities (drive currents, voltages) as well as combinations of these sizes. This allows one achieve dynamic change in the differential angle setpoint in order for example, the register differences between the individual printing units To be able to optimize machine speed changes.

• Durch den Einsatz von Längswellen im Antriebsstrang einer Druckmaschine wird lediglich eine feste, unveränderbare Versteifung durch einen fest eingestellten Differenzwinkel erreicht. Demgegenüber bietet die Differenzwinkelregelung die Möglichkeit, veränderliche, dem Druckauftrag angepasste Steifigkeiten nachzubilden. Diese Veränderungen können während des Druckbetriebs durch entsprechende Algorithmen, die in der Differenzwinkel-Sollwertvorgabe hinterlegt sind, vorgenommen werden.
• Durch die Mehrmotoren-Antriebstechnik ist die Anzahl der Units innerhalb einer Bogen-Druckmaschine nicht begrenzt. Bei der Längswellentechnik nimmt mit zunehmender Unit-Anzahl die Grenzfrequenz stetig ab, so dass die maximal mögliche Maschinendrehzahl sinkt.
• Mit Hilfe der Mehrmotoren-Antriebstechnik lässt sich eine automatisierte Zahnspielausstellung bei beliebigen Betriebszuständen verwirklichen.
• Auf Grund der Weiterentwicklungen der Mehrmotoren-Antriebstechnik ergibt sich eine höhere Wirtschaftlichkeit gegenüber der momentan eingesetzten Längswellentechnik.

This has the following advantages over the prior art:

• By using longitudinal shafts in the drive train of a printing press, only a fixed, unchangeable stiffening is achieved by a fixed difference angle. In contrast, the differential angle control offers the possibility of simulating variable stiffnesses that are adapted to the print job. These changes can be made during the printing operation by appropriate algorithms, which are stored in the differential angle setpoint specification.
• The number of units within a sheetfed press is not limited by the multi-motor drive technology. With longitudinal shaft technology, the limit frequency steadily decreases as the number of units increases, so that the maximum possible machine speed drops.
• With the help of multi-motor drive technology, an automated tooth play exhibition can be implemented in any operating condition.
• Due to the further developments of the multi-motor drive technology, there is greater economic efficiency compared to the longitudinal shaft technology currently used.

These speed control loops are given identical basic speed setpoints fed. With the exception of a master drive, each slave drive receives one Another setpoint, the additional speed setpoint, which is generated by the slave drive assigned differential angle controller is formed.

The invention permits numerous embodiments. One of them should be based on the figures shown in the drawing are explained in more detail.

Figur 1:

erfindungsgemäße Vorrichtung

Figur 2:

Impulsverlauf pro Zahnradumdrehung

It shows:

Figure 1:

device according to the invention

Figure 2:

Pulse curve per gear revolution

FIG. 1 shows a printing press 1, which consists of a feeder 2, a plurality of subunits 3 to 6 designed as printing units, and a delivery arm 7. The printing machine 1 is driven from the feeder 2 via the printing units 3 to 6 to the delivery unit 7 via a closed gear train 8, which is formed by intermeshing gear wheels 8a to 8h. About this mechanical gear train 8 in the individual printing units 3 to 6 not further described blanket cylinders, which cooperate with impression cylinders and the transfer cylinders arranged downstream of the impression cylinders.
The path of the printing material in the configuration shown in FIG. 1 takes place in the direction of the arrow from right to left.

Two position-controllable individual drives 9 engage at two points of the gear train 8 and 10 a. Each position-controllable individual drive 9 and 10 is an electric motor formed, the individual drive 9, the sub-units 3 and 4 and Single drive 10 drives the sub-units 5 and 6 and the boom 7.

A pulse generator 11 is opposite to the shaft 17 of the gear 8d and a another pulse generator 12 is opposite the shaft 16 of the gear 8c arranged. Each shaft 16 and 17 has a projection 18 and 19, respectively.

Both pulse generators 11, 12 are designed so that they are accurate in one defined angular position of the two gears 8c, 8d when the Projection 18 and 19 each have an electrical pulse per gear revolution output. In Figure 2, the upper representation shows the pulse curve on Pulse generator 11 and the lower illustration shows the pulse curve on the pulse generator 12, as it is from a control unit 13 connected to the pulse generators 11 and 12 is detected.

In addition, the control unit 13 is directly connected to the individual drives 9 and 10 connected and acts on the individual drives 9 via an actuator 14 and 15, respectively and 10 a.

When the printing press is operating, the control unit 13 accesses the individual drives 9 and 10 and forces the drive elements 9 to run synchronously with the angle of rotation and 10 at the entry points. The control unit 13 determines the actual position of each individual drive 9, 10 and compares this with the Control unit stored setpoints. Based on this comparison each individual drive 9, 10 from the control unit 13 individually via the actuator 14, 15 controlled. The individual drive 9 is at the angle ϕ 1 and Single drive 10 rotated by the angle ϕ2.

The individual drives are to be set by a setpoint value determined according to the invention 9 and 10 are controlled such that in addition a predetermined constant Twist Δϕ of the gear train between the input points of the individual drives 9, 10 is guaranteed. Indicator of the presence of such Twist Δϕ is that the tooth flanks of two adjacent, intermeshing gears on meshing a under operating conditions just touch and possibly transfer a small load.

The time interval .DELTA.t that results from the pulse curves Pulse generators 11, 12 measured pulses and its temporal changes measured by the control unit 13 and in at a constant engine speed converted a proportional angle of rotation difference.

For the correct determination of the angle of rotation difference Δϕ between the input points the individual drives 9, 10 when the control is switched off Individual drives 9, 10 the pulses supplied by the pulse generators 11, 12 evaluated.

For this purpose, the printing press 1 is first determined to produce Load conditions brought into a predetermined operating state in which the Colors provided in the printing units and the printing units switched on become. A machine speed is also set. Then will on the individual drive 9 by the control unit 13 a lag compared to Single drive 10 generated and increased until the time difference Δt1 constant between the pulses generated by the pulse generators 11 and 12 remains. The constant time difference Δt1 is stored in the control unit 13.

The control unit 13 then controls the individual drive 9 in the opposite direction Direction so that there is an advance at the input of the individual drive 9 sets the drive of the individual drive 10. This lag is long as well increased until the time difference between that of the pulse generators 11, 12 emitted pulses is constant. The constant time difference Δ t2 determined in this way is stored in the memory of the control unit 13. In addition, the location of the Electric motor determined after setting the lead and to determine the Angle of rotation difference Δϕ2 used analogous to the lead.

The control unit 13 then subtracts the time difference Δ t2 and calculates it from this an angle difference Δϕ2, to which the angle difference Δϕ2 is added.

The angle difference Δϕ determined in this way is called the setpoint Production conditions of the regulation of the individual drive 9 by the Control unit 13 used as a basis. It is always a light touch system the tooth flanks in a predetermined direction of movement of the gear train 8 guaranteed.

In addition to the empirically determined advance, a further advance Δϕ 3 generated by the control unit 13 for driving the individual drive 9. This Lead Δϕ 3 is determined from the desired operating load Printing machine in meshing and the wheel stiffness. It is advantageous the advance Δϕ 3 to a map stored in the control unit 13 remove. This lead Δϕ 3 is added to the lead Δϕ and at Regulation of the individual drive 9 is also taken into account as the setpoint.

The method according to the invention is for different configurations of the Printing machine applicable. The number and formation of the sub-units are 3 to 6 variable and can vary from press to press.

To determine a setpoint, that is, the rotation Δϕ between the Entry points of the individual drives 9, 10 can also be provided Varying the drive torque of the first and second individual drives 9, 10 or that to determine the setpoints for the position control one at a certain ratio of those to be fed in by the individual drives Torques resulting in torsion Δϕ is determined. During test runs of the machine, the snapshot of the Individual drives measured by special sensors or via the current values of the Drive motors determined indirectly.

For this purpose, this is preferably done via the first drive 9 in the gear train 8a-8h injected drive torque increased so that to maintain a predetermined speed, the torque to be fed in via the second drive 10 gets smaller. The fed via the first and second motors 9, 10 Moments are compared and used to determine a setpoint for the position control of the two individual drives, i.e. for the rotation Δϕ of Wheel train 8a - 8h used. An angle value Δϕ can be determined in this way corresponds to a certain torque ratio. Training can also be provided, the determination of angles of rotation Δϕ at different Perform speeds and / or different load situations.

In another embodiment of the invention for determining a Setpoint specification (determination of the angle of rotation Δϕ) is provided, initially to drive the machine via the first drive motor 9, so that is guaranteed there is a flank system in the entire gear train. Thereupon is de-energized switched motor 9, the second drive motor 10 and driven by Movements carried out by the wheel are detected via the position encoder (pulse or Angle encoder) 11, 12 detected. This is, in particular, that of the second motor 10 executable angle amount can be determined until the by reversing the Flank system in the gear train 8a - 8h is brought out. The way certain angular amount can then be used as the angle of rotation Δϕ of the setpoints Position control of the individual drives 9, 10 are used.

reference numeral

1

press

2

investor

3

printing unit

4

printing unit

5

printing unit

6

printing unit

7

boom

8th

gear train

8a-8h

gears

9

individual drive

10

individual drive

11

pulse

12

pulse

13

control unit

14

actuator

15

actuator

16

wave

17

wave

18

head Start

19

head Start

Claims (20)

A method of operating a printing press, particularly an offset sheet printing press, in which two independently-driven, position-controllable individual drives in a continuous gear train feed, thereby coupled with the gear train part units of the printing machine are driven and generates a rotation of the wheel train between input drive points of the individual drives characterized that the rotational angle position of the wheel train is measured at two different positions, the position of an individual drive being set as a function of the difference resulting from these rotational angle positions. A method according to claim 1, characterized in that the rotational angle difference of the gear train is determined before the start of the printing process depending on a predetermined operating state of the printing press and the individual drive is biased during the printing process by this rotational angle difference. A method according to claim 2, characterized in that after setting the predetermined operating state of the printing press, the gear train is moved by the individual drive in a predetermined direction of rotation, the difference in the rotational angle positions within the gear train being determined by moving the gear train until one with multiple measurements constant rotation angle difference of the wheel train is determined. A method according to claim 3, characterized in that the position of the position-controllable individual drive is determined before the movement of the gear train and after reaching the constant rotation angle difference of the gear train, a rotation angle difference of the individual drive being determined from the two positions and from the sum of the rotation angle difference of the gear train and Rotation angle difference of the individual drive the tension is determined by which the individual drive is biased during the printing process. A method according to claim 4, characterized in that a further angle of rotation difference is set on the individual drive during the printing process, which is determined from a predetermined operating load and / or the wheel tension stiffness. A method according to claim 1, characterized in that the speed setpoints for the individual drives are formed as the sum of a basic speed setpoint and additional speed setpoints, the latter being generated from the differential angle controllers. A method according to claim 1, characterized in that the differential angle setpoints as a function of: Momenta, Force quantities (torques), electrical quantities, and their combination are generated. A method according to claim 1, characterized in that the differential angle setpoint values are determined individually for each machine. A method according to claim 1, characterized in that the determination of the actual values for the differential angle controller between any, not necessarily adjacent drive axes is carried out by forming the difference between the associated actual angle signals or by forming the difference between the actual speed signals with subsequent integration. A method according to claim 1, characterized in that at least 2 sensors arranged at different positions of the wheel train provide angle information as a function of variable operating states of the printing press (e.g. rotational speed, temperature) and with the aid of a plurality of temporarily varied target differential angles, basic target values for the differential angle control of the individual drive axes can be determined relative to one another. Method according to Claim 1, characterized by the following method steps carried out on a multi-motor drive with 2 drives: bring the machine into a relevant operating state (e.g. color in the inking units, pressure on, machine speed not equal to zero) Force an advance on the input and increase until Δt does not change, the final value Δt _{1 reached} is saved Force lag on the input and increase until Δt no longer changes, the final values Δt ₂ and Δϕ ₂ are saved calculate an angle rotation Δϕ ₂ * from Δt ₁ -Δt ₂ Force a lead on the input according to Δϕ ₂ + Δϕ ₂ * (differential angle setpoint) or save this value as a potential base differential angle setpoint for recourse to the relevant operating state. A method according to claim 1, characterized in that to determine the setpoints for the position control, a rotation Δϕ resulting in the gear train at a specific ratio of the torques to be fed in by the individual drives is determined. A method according to claim 12, characterized in that rotations Δϕ are determined for different load and or speed situations of the printing press. A method according to claim 1, characterized in that to determine the setpoints for the position control, a rotation Δϕ is determined, which corresponds to a rotation of the gear train between the individual drives due to tooth flank changes. A method according to claim 14, characterized in that with the first drive motor, a defined tooth flank system is first generated in the gear train, that the first drive is switched off, that the second drive is activated, and that the movements in the gear train caused thereby are determined and for determining an angle of rotation Δϕ can be used. Drive for a printing press, in particular a sheetfed offset printing press, for carrying out the method according to claim 1, in which a control unit is connected to two position-adjustable individual drives which can be acted upon independently of one another and feed the individual drives at two different points into a continuous wheel train which is connected to the subunits of the printing press Coupled, a position-controllable individual drive being acted upon by the control unit with a setpoint value, whereby the gear train can be pretensioned between the two individual drives by a predetermined angular amount, characterized in that two position sensors (11, 12) arranged at different positions within the gear train (8) ) are connected to the control unit (13) and the position sensors (11, 12) of the angular position of the gear train (8) in these positions deliver corresponding signals to the control unit (13) which, depending on these angular positions, provide a signal n Set position value with which an individual drive (9) can be acted upon during the printing process. Drive according to claim 16, characterized in that the position sensors (11, 12) detect the angular position of two adjacent gear wheels (8c, 8d) of the gear train (8), each position sensor (11, 12) emitting a signal per gear wheel rotation, from which the Control unit (13) calculates an angle of rotation difference for determining the setpoint value under predetermined operating conditions. Drive according to claim 16 and 17, characterized in that the control unit (13) applies a setpoint to the individual drive (9), which can be determined from the difference in rotational angle of the gear train (8) and a difference in rotational angle of the individual drive (9). Drive according to claim 18, characterized in that each individual drive (9, 10) drives a predetermined number of sub-units (3, 4, 5, 6, 7) of the printing press (1) via the gear train (8). Drive according to claim 16, characterized in that each individual drive (9) is assigned a speed control loop cascade, consisting of speed controllers and subordinate current or torque control circuits, with a differential angle controller which effects coupling of the individual drives.

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