DE102004062112A1 - Sheet-fed rotary printing press, with a motor control, has a measurement of the rotary oscillation of the rotary components for compensation parameters to overlay the motor control and compensate for register deviations - Google Patents

Abstract

A motor control (A) compensates for register differences in a sheet-fed rotary printing press, through rotation oscillations in the rotary components at the printing stations (DW1-DW4) with a main drive motor (M), taking the sheets from a sheet supply station (AN). Rotation oscillations are established once with the ensuing register deviations between the printing stations in a resonance rotary speed range under printing conditions within a rotary printing speed range. Counter harmonic compensation torques are determined from discrete harmonic components of the rotary oscillations in the resonance rotary speed ranges. Their parameters are stored and arranged according to the resonance rotary speed ranges in the control. The drive torque of the main motor is overlaid with the stored compensation torques according to the rotary speed. The control has a module (KM) for compensation parameters.

Description

The The invention relates to a method for compensation of rotational vibration caused Register deviations in a rotary printing machine with a printing and / or Lackwerke connecting drive wheel train and acting on the drive wheel train Main drive motor.

Under Passer deviations become relative position deviations when overprinting successively applied in the individual printing or coating units Partial print images (color separations) or Paint layers understood. Systematic register deviations between the partial print images can by inaccuracies in the printing forme production, misplaced Printing form, handling differences in the print image transfer on the substrate or printing stock error occur. These Errors are with known actuating means on the printing or coating units easy to control.

object numerous efforts is the elimination of registration errors caused by rotational vibrations the printing material-carrying body of revolution arise.

at Sheet-fed rotary printing presses are standard, at least the impression cylinder the individual printing units and arranged between the printing units Transport or transfer cylinder with a gear train to mechanically couple with each other and this Antriebsräderzug means to electrically drive a main drive. The drive wheel train one Forming printing machine with the rotational bodies coupled thereto a vibration system whose dynamics are characterized by load moments, spring constants, moments of inertia etc. is determined. The uniform rotation The elements of this drivetrain can be angle-dependent, with each Rotation periodically recurring (synchronous) rotational vibrations and non-periodic (asynchronous) rotational vibrations are disturbed.

ever more printing units has a sheet-fed press, the larger it gets the tendency to oscillate.

emergence sources of periodic rotational vibrations in sheet-fed rotary printing presses Load torque fluctuations in the drive wheel train by clock or rotation angle bound Working movements of cam gears (feeder gear, traversing movements in the inking unit), centering errors of gears and especially discontinuities in rolling contact of cylinders, in particular through cylinder channels, as well as opening and closing movements of Gripper systems.

torque fluctuations to lead due to the elasticity the drive gears to individually different deviations from the desired angular position or to deviations in the synchronicity of the rotational movements until towards tooth flank changes on the meshing drive gears.

The from the vibration source in the drive wheel train excited rotational vibrations sit down over the meshing gears of the drive wheel train over the entire printing machine continues, with the synchronous rotational vibrations because of the integer ratio Although their frequency to the rotation frequency cause wear, but less problematic for the assurance of printing accuracy are because they are always in the same Angular position of the rotating body occur and therefore always the same, repetitive position errors which compensates with known register facilities can be.

Are disturbing on the other hand, all non-periodic (asynchronous) rotational vibrations with a non-integer frequency ratio to the speed, because they are yourself as a constant changing fluctuations of the rotational angle difference between the adjacent bodies of revolution and thus as a quality-critical registration error / duplication error to make noticable. For example, asynchronous vibrations occur in the coupling of machine elements via gears with non-integer ratios.

The Rotation vibrations show at certain frequencies (natural frequencies) time constant, characteristic amplitude local distributions (natural modes) over the Length of the printing machine, at least at the ends of the drive wheel train, that is i. a. the first and last printing or varnishing, to reach local extremes. The Natural frequencies and eigenmodes are from the vibration excitation independent Properties of a printing press and depend on the number of printing units and the construction of the machine, the vibrations in the dominate first eigenform with the lowest natural frequency, i. the largest vibration amplitudes and therefore special attention in the vibration analysis of a Find printing press.

In the case of vibration excitation in the drive wheel by disturbing rotational vibrations with a frequency near a natural frequency of the printing press it comes to resonance, ie oscillations, which manifest themselves in speed-dependent, inadmissibly high Übergabepasserabweichungen between the applied in the individual printing or coating units partial printing images or layers of paint , Continue to lead this Resonances to heavy loads on the drive elements and for wear promotion.

rotational vibration can be reduced by passive and active additional systems. So far Known facilities are based on non-specific compensation all occurring, periodic and non-periodic rotational vibrations directed, for what consuming vibration sensor and control loops are required.

In the DE 44 12 945 A1 discloses an apparatus and a method for reducing rotational vibrations of printing presses by means of actuators, which may also be drive motors, wherein data for driving the actuators are determined either by measurement with vibration, calculation or in a test run of the printing machine. The formation of the control signals for the actuators is not described in detail.

The DE 199 14 627 A1 relates to a method and a device for compensating the torsional vibration in a printing machine, which is designed such that at least one eigenform of the printing press is determined and that for at least one location where this eigenform does not have the amplitude 0, a respective counter-momentum for the compensation the moments which stimulate vibrations in the eigenform is applied by a cam gear or an additional motor. Counter torques can be determined for a medium speed or for different speeds and machine parameters. Again, it remains unclear how the opposing moments are formed. A disadvantage is the cost of additional Schwingungskompensatoren.

The DE 101 49 525 A1 describes a method and apparatus for compensating mechanical rotational vibration by superimposing at least one discrete frequency component of the rotational vibration on a harmonic torque of equal frequency applied by an actuator, the frequency being determined online as a function of natural frequency and machine speed. The device comprises a costly adaptive control loop with a vibration sensor and the harmonic compensation torque of the same frequency directly or indirectly on the machine shaft applying actuator, which may be a drive motor. A disadvantage is the orientation of the method to the maximum vibration compensation on only one machine shaft.

From the EP 0 592 850 B1 a device and a method is known, which provides active actuators, such as motors, to the individual cylinders to control the motors via control circuits such that the oscillations repel actuating forces. This is not a targeted counter-strategy against vibrations in the machine-specific eigenmodes, but the asynchronous, ie only non-periodically occurring with the revolutions of the rotating parts vibrations are measured and then fought at the place of measurement. In this way, however, the compensation is not optimized in time and requires a high control effort, with the risk that the control either has too long a time delay or in turn causes vibrations.

The known vibration compensation method is still the disadvantage together that they are not geared to a minimum print quality to be achieved are.

Of the Invention is based on the object, starting from the disadvantages from the prior art, a method for reducing Rotationsschwingungsbedingten Passer deviations that with existing means an avoidance of pressure quality reducing Passer deviations on all printing or coating units of a rotary printing machine allows.

According to the invention Task by a method having the features of the first claim solved. Appropriate further education of the method are the subject of the dependent claims.

Of the The basic idea of the invention is, in contrast to the known Objective of the maximum reduction of the rotational vibrations in all operating situations, which inevitably leads to complex solutions, the vibration-reducing measures on the one hand, only on resonance speed ranges, in which actually Druckqualitätsbeeinträchtigende and wear-promoting vibration peaks occur, restrict, on the other hand, however, compliance with a given print quality (maximum allowed Register tolerances) on all printing and / or coating units of the printing machine (e.g., at the sheet transfer points between the printing or coating units of a sheetfed press) with existing To ensure funds.

This is inventively stored by superposition of the drive torque of the main drive motor with stored within the drive control, the resonance oscillations counteracting, speed-dependent counter moments in the Resonance speed ranges achieved. At different speeds different harmonic compensation moments are used with speed-dependent amplitudes for vibration damping.

The Compensation moments become unique in test runs under practical pressure conditions determined or calculated from design data and with speed-dependent proportions superimposed as a permanent-acting algorithm the drive motor current in the later printing operation. This is the surprising Fact that even the disturbing asynchronous vibrations muted when the synchronous (periodic) oscillations with harmonic Counter moments are compensated.

The inventive method has the economic benefits of having it with the existing main engine is feasible and no additional Vibration compensators needed. Instead of complex Control circuits is merely a programmable control module for the main drive motor current required. Furthermore, the proposed method guarantees with a minimum of compensation means the assurance of print quality at all Printing or coating plants.

The inventive method will be explained in more detail using the example of a sheet-fed rotary printing press. The associated Drawings show in

1 a schematic representation of a sheet-fed rotary printing press with rotational vibration measuring devices and vibration compensation

2 Eigenmodes of the resonant vibrations

3a an example of a resonance diagram for a vibration system with two natural frequencies

3b Rotation vibrations as a function of the speed

3c Compensation moments in resonance speed ranges

4a the drive torque of the main drive motor

4b Compensation moments in the drive motor current

In 1 By way of example, a sheet-fed rotary printing press in a row construction with a sheet system AN, printing units DW1 ... 4 and a sheet delivery AU is shown schematically. Of the printing units, only the vibration-relevant sheet-guiding printing cylinder DZ1 ... 4 and the transfer drums ÜT1 ... 3 are shown. At least these rotational bodies are synchronized in their rotational movement via a continuous drive wheel train ARZ. The drive torque M _{A of} a main drive motor M for the printing press is fed via the printing cylinder DZ1 of the first printing unit DW1 in the drive wheel ARZ. The main drive motor M is controlled by a drive control A speed and torque.

In a sheet-fed rotary printing machine, a large number of working movements occur, which are connected with load changes. In this case, periodic (synchronous) and asynchronous rotational oscillations S are excited in the uniform rotational movement of the rotation bodies DZ, ÜT connected in the printing or coating units via the drive wheel train ARZ. If the load change amplitudes exceed a certain level, oscillation peaks S _R > S _zul occur in the resonance rotational speed ranges n _R in certain sections of the drive wheel train ARZ, in which the natural vibrations of the printing press are particularly pronounced, and thus to impermissible fluctuations in the rotational angle positions during the sheet transfer of one Gripper system to the following gripper system (transfer register) and thus to a no longer tolerable impairment of printing accuracy. These resonance vibrations S _R > S _zul, which are relevant for the print quality, are detected metrologically and subjected to a Fourier analysis.

a_i

= Amplitude der i-ten harmonischen Schwingung

b_i

= Phasenverschiebung der i-ten harmonischen Schwingung

t

= Zeit

n

= Drehzahl

i

= ganzzahliges Verhältnis zwischen der Frequenz f der Störung und der Druckmaschinendrehzahl

Thereafter, oscillations S can be described as the sum of i discrete harmonic oscillations with different proportions a _i frequencies and phase positions b _i , wherein the frequencies f are integer multiples (orders) i of the rotational speed n: f = i · n. S = a 0 + a 1 · Sin (t · (1 · n) + b 1 ) + a 2 · Sin (t · (2 · n) + b 2 ) + ... + a i · Sin (t · (i · n) + b i ) (1) With

a _i

= Amplitude of the i-th harmonic oscillation

b _i

= Phase shift of the i-th harmonic oscillation

t

= Time

n

= Speed

i

= integer ratio between the frequency f of the disturbance and the printing machine speed

Each printing press points in the pressure rotation range between a lower printing speed n _u and an upper printing speed n _o at least one relevant natural frequency f _{eig, l} , whose value depends essentially on the machine configuration. If the frequency of fine excitation oscillation or of a harmonic oscillation component i corresponds approximately to one of the natural frequencies f _{eig, l} (resonance _{rotational speed} n _{R, l, i} ), in R, l, i = f eig, l (2) there is a resonance excitation by the ith harmonic excitation vibration. This leads to particularly high vibration excitations and thus to vibration amplitudes (resonant vibrations S _{R, l, i} ) in the drive wheel train and the cylinders and drums connected thereto, wherein at the resonance with the lowest natural frequency f _{eig, 1} the highest rotational vibration amplitudes S _{eig, 1} arise. The amplitudes a _{i of} the harmonic components of the resonance oscillations S _R generally decrease with increasing order i and at the same time the damping increases due to frictional motion sequences with increasing frequency, so that the resonances of the higher orders i result in smaller resonance oscillation amplitudes.

If the eigenfrequencies f _{eig, l of} a printing machine are known, all resonance speeds n _{R, l, i} can be determined according to (2).

The relationship between eigenfrequencies f _{eig, l} and resonance speeds n _R is based on a resonance diagram ( 3a ).

The exciter frequencies f are dependent on the rotational speed n. They can be described by the straight line equation f = i * n and form rising straight lines in a frequency / rotational speed diagram that intersect the coordinate origin. In contrast, the eigenfrequencies f _{eig, l are} parallel to the abscissa. They are constants that do not depend on the speed n, but on the concrete press configuration. The intersections between the horizontal and diagonal lines are the resonance speeds n _{R, l, i} .

For example, if the 1st natural frequency f _{eig, 1} = 6.5 Hz, then the resonance speed of the 4th harmonic oscillation n _{R, 1.4} at (6.5 / 4) s ^-1 = 5850 min ^-1 . The resonance speed of the 2nd harmonic oscillation n _{R, 1.2} is then 11700 min ^-1 , etc.

At the resonance speeds n _{R, l, i,} including a tolerance range of 10% to 20%, it can be expected that resonance vibration peaks S _{R, l, i} occur when the printing press is operated in one of these ranges, which increases for the printing press Stress and increased wear mean and lead to no longer tolerable Übergabepasserfehlern. For a consistently high print quality, it is therefore essential to prevent the formation of resonance vibrations S _R when passing through the critical resonance speed ranges n _R.

This is achieved by targeted compensation of the individual resonant speed ranges n _{R, l, i} respectively largest harmonic components of the resonant vibrations S _{R, l, i} by opposing harmonic compensation moments M _{K, l, i} .

The proposed method assumes that the eigenfrequencies f _{eig, l} and excitation frequencies f do not change significantly in a printing machine when their mode of operation is adapted to different print jobs, because the oscillation-relevant influencing variables, such as the elasticity of the drive wheel train ARZ, the inertia of the rotating Cylinder DZ and drums ÜT or active peripheral aggregates are not subjected to vibration-relevant changes from print job to print job. Therefore, it is sufficient if resonance speed ranges n _R and associated compensation moments M _K for a characteristic of the later use of the printing press configuration and operation under real pressure conditions once averaged. The torque moments M _A superimposed compensation moments M _K will lead to an effective vibration reduction in all subsequent print job-related operating variants of the printing press.

Advantageously, in a printing press by the friction in the inking and dampening a heavily damped vibration system. The damping increases with increasing speeds n, so that usually only the first natural frequency f _{eig, 1} leads to critical resonance vibrations S _R. At the same time, there are few relevant harmonic components of the resonance vibrations S _R with high vibration amplitude a _i and thus the print speed range n _u ... n _o few to consider resonance speed ranges n _R, so that the cost of determining the resonance vibrations S _R in the drive gear train ARZ and the opposing, these compensating torques M _{K is} relatively low and must be operated only once in an already be performed test run.

First, the rotational vibrations S occurring when passing through the printing speed range n _u ... n _o in mandatory test runs of the sheet-fed rotary printing press under pressure operating conditions, which usually take place at the printing press manufacturer, at locations that are crucial for a passerhaltigen pressure detected. In sheet-fed rotary printing presses that are the printing cylinder DZ, as a Drehwinkelabwei chung of a printing cylinder DZ in the sheet transfer to a circumferential displacement of the sheet position (transfer register) or a rotation of the printing cylinder DZ with respect to the printing partial image on the sheet transferring printing plate and blanket cylinders lead to Umfangsregisterabweichungen the printed image on the sheet.

For this purpose, the printing machine is preferably equipped on each printing cylinder DZ1... With one rotary encoder G for the test runs ( 1 ). The rotary encoder G, which is not required for the printing machine control, is dismantled again after the test runs have been completed and reused for further measurements on other machines, so that the metrological effort remains low.

The rotational oscillations S in the drive wheel train ARZ are determined by time-synchronous interrogation of the rotational angle positions φ of the pressure cylinders DZ1 ... and subtraction Δφ between the respectively adjacent pressure cylinders DZ or - with reduction of the vibration measurement to the first natural frequency f _{eig, 1} (see eigenform S _{eig, 1} . 2 ) - between the rotary encoders G on the first and last impression cylinder DZ1, DZ of the printing press, with which the maximum oscillation amplitude can be measured, determined. Taking into account the pressure cylinder diameter, the rotational angle differences Δφ produce the amplitudes of the rotational oscillations S at the pressure cylinder peripheries (FIG. 3b ). The rotational vibrations continuously change the relative position of the gripper systems of the adjacent printing cylinders and transfer drums DZ, ÜT at the moment of sheet transfer. Simultaneously with the rotational angle measurements, the determination of the register deviations between the partial printing images applied in the individual printing units takes place by off-line or online evaluation of the printed sheets. The register deviations correlate with the amplitudes of the rotational oscillations S and form the decisive criterion for determining the critical resonance speed ranges n _R , in which vibration-reducing measures are required. Transfer register deviations, which lie outside of the permissible tolerance range of S _zul ≤ 10 μm in sheet-fed offset printing, mark the print quality-critical resonance rotational speed ranges n _{R of} a sheet-fed offset printing press.

The rotational vibrations S _R in the pressure-quality-critical resonance rotational speed ranges n _R are subjected to an online Fourier analysis and are divided into i components with respectively different amplitude a _i , frequency n · i and phase position b _i . When passing through the individual resonance speed ranges n _{R, l, i} , the amplitudes a _{i of} the discrete harmonic vibration components determined by Fourier analysis change as a function of speed. The harmonic vibration components with the highest amplitudes a _i in a resonant rotational speed range n _{R, l, i} are stored with opposite phase positions for each associated resonance rotational speed range n _{R, l, i} as parameters for the compensation torques M _{K, l, i to} be applied. Memory values are the frequency n * i, the speed-dependent amplitude a _{K, i} (n _{R, l, i} ) and the phase position b _{K, i} .

The oscillation analysis can also be extended to the pressure rotational speed ranges lying outside the resonance ranges n _R , so that continuous amplitude-rotational speed functions of the compensation torques M _K for the entire pressure rotational speed range n _u ... n _o are stored.

In general, the print speed range n _u n _o ... due to the higher speeds n increasing vibration damping few natural frequencies f _prop, there are _k that lead to relevant print quality reducing resonance vibrations S _R. As a rule, these resonant oscillations S _{R also} have only a few discrete harmonic components whose frequency f leads to resonance within the pressure rotational speed range n _u ... n _o , so that only a small number of compensation torques or their parameters are to be stored ( 3b ). If the resonance vibrations S _{R, l, i} in a resonance speed range n _{R, l, i are} so small that they do not exceed the permissible tolerance range S _zul for the transfer register, they can be disregarded. In the example of 3b this is true for the resonant speed range n _{R, 2.6} .

Since the compensation of the resonance oscillations S _{R should} preferably take place via the drive torque M _{A of} the main drive motor M fed into the drive wheel train ARZ and not at the individual points of origin of the rotational oscillations S themselves, in a further method step the transfer functions, ie degrees of damping and phase shifts of the introduced compensation moments M have to be compensated _K between the main drive M and the vibration sources are taken into account. The transfer functions can be obtained from a vibration model of the printing press, but to do so, the position of the vibration sources must be accurately identified and the cost of modeling printing presses is very high. In the interest of simplifying the method, it therefore seems expedient to optimize the compensation parameters empirically in a further test run. For this purpose, the compensation moments M _{K, l, i} in the associated resonance speed ranges n _{R, l, i} are generated individually by appropriate modulation of the drive motor current I _{M of} the main drive motor M and superimposed on the continuous drive torque M _A , wherein first the phase position b _{K, l, i} is changed until a vibration damping at all Bogenüber registrations. Thereafter, there is an increase in the amplitude a _{K, l, i of} the compensation torque M _{K, l, i} until the amplitudes of the register deviations are at all measuring points at or between the printing units within the predetermined tolerance limit S _zul . It is not a maximum vibration damping at a sheet transfer point decisive, but compliance with the tolerance limit for the required print quality at each sheet transfer point.

The thus optimized compensation parameters a _{K, l, i} , b _{K, l, i} and associated speed ranges n _{R, l, i} are stored in the drive control A of the main drive motor M. For this purpose, a separate compensation module KM can be provided which, via an existing interface for the drive control A when passing through the resonance speed ranges n _{R, l, i, transfers} the compensation parameters stored therefor to the current control, which modulates the drive motor current I _M required for the printing operation according to a programmable algorithm such that the counter-torques M _K required for the compensation are impressed on the drive torque M _A , wherein only the compensation parameters (a, b, i) _{K, l, i} determined when driving through the resonance rotational speed ranges n _{R, l, i} are activated ( 3c and 4 ). In the resonance speed range n _{K, l, i} then the counter-torque acts M K, l, i = a K, l, i (n K, l, i ) · Sin (t · (i · n K, l, i ) + b K, l, i ). (3)

If the printing machine oscillates at resonance in one of the natural frequencies f _{eig, l} , time-constant oscillation amplitude profiles S _{eig, l} (eigenmodes) form over the length of the printing press ( 1 and 2 ), wherein the vibration amplitudes of the relevant first and second eigen forms S _{eig, 1} , S _{eig, 2 have} local extrema on the outer printing units (in the example DW1 and DW4), so that with an arrangement of the main drive motor M at the first printing unit DW1 after the sheet system AN, ie at a location of the occurrence of high vibration amplitudes, favorable conditions for an effective compensation of the resonant vibrations S _{R are created} via the main drive M.

The inventive method is instead of Antriebsstromomodulation on the main drive motor M also feasible with a torque overlay by another drive, which may be any, acting on the drive wheel ARZ motor whose drive or braking torque forms the compensation moments M _K in the drive wheel ARZ. For example, a single drive on a plate cylinder in the printing operation remain connected to the drive wheel train ARZ and feed the compensation torques M _K independently of the main drive motor M in the drive wheel train ARZ.

Although the for a typical operating condition of the rotary printing machine determined and stored compensation parameters even with print job-related changes the vibration behavior of the printing press a sufficient damping effect unfold, the procedure can be determined by identification and storage the one for characteristic, often Repetitive deviating operating conditions optimal compensation parameters be improved. Different operating conditions of the rotary printing machine are, for example, by different operating modes of attachments or gears with different damping properties, turning on or off individual peripheral functional groups or by different friction of the ink-carrying cylinders or rollers created. If for each of the characteristic operating conditions in the test runs for optimal Compensation parameters determined and stored in the compensation module KM and later Practical printing mode depending on the operating state in the drive control A can be activated, at least for print jobs with default machine settings always optimal vibration compensation can be achieved.

The inventive method can advantageously be extended by an automated adjustment of the compensation moments M _K to the mode-dependent changes in the vibration behavior of the printing press during printing operation, if at least two rotary encoder G are permanently present on the printing press (eg rotary encoder G at the beginning and end of the drive wheel train ARZ as it is known for sheet-fed rotary printing presses with turning device, for example).

Through a continuous detection of amplitudes a _i and phase positions b _{i of} the rotational vibrations S with the aid of programmed filter algorithms, the current oscillation parameters of the resonance oscillations (S _R ) can be continuously determined during the printing operation in automated cycles, corrections are made to the stored compensation parameters and the drive torques (M _A ) are superimposed with the corrected compensation moments M _K.

The parameters of the compensation moments M _K can thus be adapted cyclically to the operating state of the rotary printing machine and cause an optimal resonance oscillation compensation at any time. The update cycles for the compensation parameters are expediently from the machine control when activating the rele for the respective operating state triggered various settings.

The inventive method is also applicable to dynamically separated sub-machines with separate drive motors M _j , such as on printing groups j before and after a turning device, if this forms a separation point in the drive wheel ARZ and the Antriebsräderzug in two dynamically independent drive wheel trains ARZ _j , each with a drive motor M _{j is} split. In these cases, the resonant vibrations S _{R, j} in each submachine j or printing or coating unit group j are detected separately and compensated separately with the associated drive controls A _j and the associated main drive motors M _j .

A, A _j

drive control

AT

sheet feeder

ARZ, ARZ _j

drive wheel

AU

Stacker

DW, DW1 ...

Print- or coating plants

DZ, DZ1 ...

pressure cylinder

G

Rotary encoder

M, M _j

Main drive motor

l _M

Drive motor power

KM

module for compensation parameters

M _A

drive torque

M _K

compensation torque

S

Rotational vibration, vibration excitation

S _eig

eigenform

S _R

resonant vibration

S _perm

permissible tolerance range for rotational vibrations

ÜT, ÜT1 ...

Transfer drum

a

amplitude the rotational vibration

a _K

amplitude the compensation oscillation

b

phasing the rotational vibration

b _K

phasing the compensation oscillation

f

frequency the rotational vibration, exciter frequency

f _eig

natural frequency

i

order of the discrete harmonic component of vibration, (exciter ord

voltage)

j

dynamic independent Printing or coating group

l

order the natural frequency

n

rotation speed

n _o

upper Printing speed

n _R

Resonance speed

n _and

lower Printing speed

Δφ

Rotation angle difference between the printing cylinders

φ

angle of rotation

Claims (10)

Method for compensating rotational vibration-caused register deviations in a rotary printing press with a drive wheel train connecting pressure and / or coating units and a main drive motor, which is assigned a drive control, with the following steps: - single detection of rotational oscillations (S) in the drive wheel train (ARZ) and of assigned register deviations at the printing or coating units in resonant speed ranges (n _R ) during passage through a pressure speed range n _U to n _O under pressure conditions, - determination of discrete harmonic components of the detected rotational vibrations (S) for the resonance speed ranges (n _R ) in which Register deviations occur outside a permissible tolerance range, - determination of parameters for opposing harmonic compensation moments (M _K ) from the harmonic components of the detected rotational oscillations (S), - storage of the parameters d it compensating moments (M _K ) and their assignments to the resonance speed ranges (n _R ) and - speed-dependent superposition of the drive torque (M _A ) of the main drive motor (M) in the resonance speed ranges (n _R ) with the stored compensation moments (M _K ) in the printing operation. Method according to Claim 1, wherein the parameters for the compensation torques (M _K ) in the drive wheel train (ARZ) are determined and stored for different operating states of the rotary printing press and superimposed on the drive torque (M _A ) depending on the operating state. Method according to Claim 1 or 2, in which the determined compensation moments (M _K ) are superimposed on the drive torque (M _A ) of the main drive motor (M) as a function of rotational speed and the parameters of the compensation torques (M _K ) are optimized. Method according to claim 1, 2 or 3, wherein the compensation moments (M _K ) are produced by modulating the motor current (l _M ) of the main drive motor ( _M ). Method according to claim 1, 2 or 3, wherein the compensation moments (M _K ) are introduced into the drive wheel train (ARZ) by a further drive motor. The method of claim 1 or 3, wherein the rotary printing machine from several printing or Lackwerksgruppen (j) each with its own Antriebsräderzug (ARZ _j ) and its own drive motor (M _j ) is formed and the compensation moments (M _{K, j} ) for each pressure or Lackwerksgruppe (j) separately determined and optimized. The method of claim 1 or 6, wherein the main drive motor (M) the first or last printing or coating unit (DW) of a rotary printing machine or a printing or coating unit group (j) is assigned. The method of claim 1, 2 or 6, wherein the detection the rotational vibrations (S) with rotary encoders (G) on pressure cylinders (DZ) takes place. The method of claim 8, wherein rotary encoder (G) at the first and last printing or Coating unit (DW) of a printing press or a printing or coating group (j) are arranged. Method according to claim 1 or 6, wherein during the printing operation in automated cycles the current oscillation parameters of the resonant oscillations (S _R ) are determined with the aid of programmable filter algorithms, then parameter corrections are made for the stored compensation moments (M _K ) and the drive torques (M _A ) with the be superimposed current corrected compensation moments (M _K ).