DE102005025742B4 - Method for controlling a short inking unit of a printing press - Google Patents

Abstract

Method for controlling a short inking unit (2) of a printing machine (1), wherein by means of a vibrating squeegee (3) ink as color relief (22) on an inking unit roller (4) is metered and then the color relief (22) by means of at least one smoothing roll (5.1) leveled is, characterized in that the smoothing roller (5.1) with slip (S) to the inking unit roller (4) is rotated, wherein the size of the slip (S) in response to at least one vibration parameter of the vibration of the vibrating doctor blade (3) is controlled.

Description

The present invention relates to a method for controlling a short inking unit of a printing press according to the preamble of claim 1.

Such a method results from the closest prior art representing EP 1 199 166 A1 , In this prior art, the leveling of the color relief is not effective enough.

Far further state of the art forms the EP 1 291 176 A2 in which printing ink is metered as a color relief on an inking roller by means of an anilox roller, wherein the anilox roller selectively places color clusters between ink splitting clumps remaining on the inking roller.

Likewise, only further state of the art form the DE 197 32 497 A1 and the DE 101 33 634 A1 , in which a color relief is leveled on an inking roller by means of a smoothing roller, wherein the smoothing roller is rotated with slip to the inking unit roller.

The invention has for its object to provide a method for controlling a short inking unit, which method enables an effective leveling of the color relief.

This object is achieved by a method having the features of claim 1.

Accordingly, the amount of slippage is adjusted to the magnitude of the vibration parameter when the magnitude of the vibration parameter is changed. This adjustment of the amount of slippage can be performed by an operating operation performed by the operator of the printing machine on a control device or by the control device, for. In accordance with a control program stored therein.

Accordingly, the differential speed existing between the peripheral surfaces of the calender roll and the inking roller in the nip formed by these two rolls guarantees an effective leveling of the ink relief in the nip. The thickness variations of the paint relief after passing through the nip are much lower than they would be if slip were not eliminated. The number of the inking roller assigned to the leveling of the color relief smoothing rollers can thus be kept low and in certain applications, even a single smoothing roller is required for adequate leveling of the color relief. In addition, the slip allows particularly high printing speeds of the printing machine and prevents the slip from the occurrence of insufficient leveling of the color relief resulting printing problems at the particularly high printing speeds.

In the following, further developments of the method according to the invention will be briefly explained in the subclaims:
According to a development, the size of the slip is controlled as a function of the frequency of the oscillation of the vibrating squeegee. This frequency of the oscillation or the period number of the oscillation per one revolution of the inking roller can be varied from print job to print job depending on the specific requirements of the respective print job. By varying the frequency of the vibration, the color relief and thus at least secondarily the metered amount of the ink is set according to the print job. The size of the slip is thus adapted to the shape of the color relief, which depends on the frequency, in order to be able to level the latter optimally with every possible form of color relief. Primarily, the dosage amount can be adjusted by means of a variation of the amplitude of the oscillation of the vibrating doctor blade.

In a further development, the size of the slip is controlled as a function of the duty ratio of the vibration of the vibrating doctor blade. The duty cycle is the ratio between the opening time, in which the vibrating doctor is turned off by the ink fountain roller, relative to the closing time, in which the vibrating doctor is set to the ink fountain roller. The sum formed from the opening time and the closing time is the period of the oscillation. The duty cycle can be changed to set a print order specific form of the color relief and thus the dosage. When changing the duty cycle can z. B. the opening time can be reduced in favor of the closing time to reduce the dosage. When changing the duty cycle, the opening time and the closing time are changed in opposite proportional to each other. The change in the duty cycle and the resulting change in the shape of the color relief is taken into account in the change in the slip, so that in every possible form of color relief this is optimally leveled by means of the smoothing roll.

Of course, the size of the slip can also be controlled as a function of both oscillation parameters-the frequency of the oscillation and the duty cycle of the oscillation.

According to a further development, the smoothing roller removes color cleavage clumps from it by cleaving the color relief and the size of the slip is controlled in such a way that the smoothing roller selectively places the color cleavage clumps in subsequent depressions of the color relief in the course of its further rotation. There is the color relief of z. B. line-shaped color clumps and depressions substantially free of ink, which are formed alternately with the Farbhäufchen, as seen in the circumferential direction of the inking roller on each color pile each followed by a sink. The color clusters are formed during the opening times of the vibrating squeegee and the sinks during the closing times. During the passage of the color piles through the nip, a color split occurs, in which each color burst is split into a color burst and a color split clump. After the color splitting, said color residue particles are on the ink fountain roller and on the smoothing roller said Farbfaltungshäufchen. These color cleavage clumps are at least partially used as a result of the corresponding slip with the rotation of the smoothing roller in the subsequent depressions of the color relief to at least partially fill the wells with ink and thereby level the color relief. The previously used phrase "partially used" takes into account that the color cleavage clumps may be subject to further color cleavage during their placement in the wells of the color relief.

The present invention also includes a printing press which comprises a short inking unit and a control device and is characterized in that the control device is designed to control the short inking unit according to the method or one of its further developments. The special design of the control device can be given by their hardware or software. For example, a function in the form of a mathematical equation, a table of values or a corresponding curve can be stored in the control device, which function describes the dependence of the magnitude of the slip on the oscillation parameter of the oscillation. By said formation of the control device, the printing machine is suitable for carrying out the method.

The disclosure of the present invention is hereby incorporated by reference EP 1 199 166 A1 fully included. All constructive features of the EP 1 199 166 A1 described printing machine can also be present in the printing machine according to the present invention. Likewise, all procedural features resulting from the EP 1 199 166 A1 also be used in the context of the process of the present invention.

Other structurally and functionally advantageous developments of the method according to the invention and the printing press according to the invention will become apparent from the following description of a preferred embodiment and the accompanying drawings.

In this shows:

1 a short inking unit with an inking roller and smoothing rollers,

2 the inking roller and one of the smoothing rollers in a side view,

3 the control technology linkage of various motors and encoders of a printing unit containing the short inking unit with a control device and

4 - 7 different variants of a slip characteristic, according to which a slip between the in 2 set rollers is set.

1 shows a printing press 1 for the lithographic offset printing in sections. In the neckline is a short inking unit 2 with a squeegee 3 as dosing for on an inking roller 4 successive dosing of ink shown. The inking roller 4 is either at ultrashort training of the short inking unit 2 an applicator roll, which rests against a printing form cylinder, or is at a somewhat longer design of the short inking unit 2 on such an applicator roll. In the direction of rotation of the inking roller 4 follow the vibrating squeegee 3 a first 5.1 , second 5.2 and third 5.3 Smoothing roller for smoothing the already metered ink on the inking roller 4 , The successively switched smoothing rollers 5.1 to 5.3 are identical and in particular the same diameter and are not on any other roller except the inking roller 4 at.

Each smoothing roll 5.1 to 5.3 is a separate electric motor 6 with slip relative to the ink fountain roller 4 associated successive rotation of the respective smoothing roll. The motors 6 are from a the ink fountain roller 4 and the printing master cylinder driving main motor 16 (see. 3 ) separate individual drives of the smoothing rollers 5.1 to 5.3 ,

2 shows the example of the first smoothing roll 5.1 the storage and the rotary and axial drive of the smoothing rollers 5.1 to 5.3 in detail. The respective smoothing roller - in 2 for example, the first smoothing roll 5.1 - is with her journals in bushings 7 rotatably mounted and axially displaceable. The bearing bushes 7 form plain bearings and are in a side frame 13 the printing press 1 used. On the one axle journal sits a narrow gear 8th firmly, with one on the engine shaft of the engine 6 tight, wide gear 9 is engaged. The other journal is with an annular groove 10 provided, in which an eccentric 11 a traversing drive 12 intervenes. The first smoothing roller 5.1 is powered by its traverse drive 12 along the inking roller 4 axially reciprocated, with the narrow 8th in the broad 9 Gear is moved. The smoothing rollers 5.1 to 5.3 , which are rotationally driven positively via the gear transmission and the traversing drives 12 are driven axially positively, so are not only smoothing rolls per se, but at the same time friction rollers.

A device for adjusting between the respective smoothing roll 5.1 to 5.3 and the ink fountain roller 4 existing roller press is present, but not shown in the drawing.

Besides, every smoothing roll is 5.1 to 5.3 a separate encoder 14 assigned to the respective engine 6 is integrated and together with this engine 6 to an electronic control device 15 the printing press 1 connected.

3 shows schematically that not only the engines 6 and the encoders 14 the smoothing rollers 5.1 to 5.3 but also the main engine 16 , one of the ink fountain roller 4 and the main engine 16 associated encoder or encoder 17 and the squeegee 3 (see. 1 ) associated with their drive vibrator 19 to the control device 15 control technology are connected.

The control of the smoothing rollers 5.1 to 5.3 takes place according to the following procedure:
By means of a z. B. in the included EP 1 199 166 A1 shown in detail ink supply device is the ink as a thick ink film 18 on the ink fountain roller 4 applied. By means of the vibrating squeegee 3 be out of the thick paint film 18 linear color patches 20 shaped, which extend in parallel to the roll axes direction. Between the color piles 20 are essentially gaps or depressions free of ink 21 , In the valleys 21 may still be a so-called lubricating film of the ink. The color piles 20 and the valleys 21 together form a color pattern or color relief 22 ,

The size of a grid - that's the color of piles 20 to neighboring color piles 20 in the circumferential direction of the inking roller 4 Distance to be measured - the color relief 22 is determined by the magnitude of a frequency f at which the vibrating squeegee 3 from the vibrator 19 is driven and to the inking roller 4 swinging back and forth. Depending on the requirements of the respective print job, the operator can be at the control device 15 select and set the required size of the frequency f and thereby the color relief 22 or change its grid width. The higher the selected frequency f, the closer the color piles become to each other 20 generated.

Likewise, the operator at the control device 15 the required for each print duty cycle of the vibration of the vibrating squeegee 3 select and set. This duty cycle describes a between the opening duration and the closing time of the vibrating squeegee 3 existing ratio and thus also a relationship between the length of the color piles 20 and the length of the valleys 21 in the circumferential direction of the inking roller 4 seen.

The smoothing rollers 5.1 to 5.3 serve to the color relief 22 to a uniform, thin color film 23 breitzuwalzen. In this of smoothing roller 5.1 to smoothing roll 5.2 Gradually increasing leveling of the color relief 22 is every smoothing roll 5.1 to 5.3 rotated at a different speed and consequently other roller surface speed. As a result, there is between the inking roller 4 and the first smoothing roll 5.1 another slip, ie a different surface speed difference, than between the inking roller 4 and the second smoothing roll 5.2 and as between the inking roller 4 and the third smoothing roll 5.3 and exists between the inking roller 4 and the second smoothing roll 5.2 another slip than between the ink fountain roller 4 and the third smoothing roll 5.3 , It turns every smoothing roll 5.1 to 5.3 with the inking roller 4 in the same direction, ie in the direction of rotation of the inking roller 4 opposite direction of rotation.

In 1 is symbolically illustrated with an arrow A, that between the first smoothing roll 5.1 and the ink fountain roller 4 existing slip by a corresponding control of the motor 6 the first smoothing roll 5.1 by means of the control device 15 is set so that on the first smoothing roll 5.1 located color splitting piles 24 in the valleys 21 be placed accurately. The color splitting piles 24 result from a first color cleavage of color patches 20 which is in one of the first smoothing roll 5.1 together with the inking roller 4 formed nip 25 he follows. As a result of this first color splitting remain on the inking roller 4 Color residual pile 26 that together with those in the valleys 21 filled in color splitting piles 24 or portions thereof a modified color relief 27 after the first smoothing roll 5.1 form that already essential more level than the original color relief 22 before the first smoothing roll 5.1 is.

The modified color relief 27 in turn, by means of the second smoothing roll 5.2 split (second color split), the second smoothing roll 5.2 Lowering the modified color relief 27 with fills from the second color cleavage Farbfaltungshäufchen. In the second color splitting in the continuous change with each other a Farbsfaltungshäufchen 24 or portion thereof and a color burst 26 of the modified color relief 27 split. The resulting from this change, different size Farbspaltungshäufchen on the second smoothing roll 5.2 are in just such a change in the subsequent sinks of the modified color reliefs 27 placed, as indicated by the arrows B and C. The result of this color smoothing results in a further modified color relief 28 even smoother than the modified color relief 27 is.

The third smoothing roll 5.3 Edits the further modified color relief 28 on the same principle as the first 5.1 and the second 5.2 Smoothing roller the original one 22 and the modified 27 Color relief. After the ink the third smoothing roll 5.3 has happened, the ink is virtually no annoying color relief more, but the thin and sufficiently leveled paint film 23 ,

From the in 1 Given representation of the gradual smoothing process is apparent that the color relief of smoothing roll to smoothing roll is always thinner and level. To ensure this, the speeds and thus the slip of the smoothing rollers must 5.1 to 5.3 be coordinated according to the function explained below: S = k (3600 * d * f / D * v * n '-1) * 100%

S [%]

Schlupf der jeweiligen Glättwalze 5.1 bis 5.3

d [mm]

Durchmesser der jeweiligen Glättwalze 5.1 bis 5.3

f [Hz]

Frequenz der Schwingung der Schwingrakel 3

D [mm]

Durchmesser der Farbwerkswalze 4

v [p/h]

Druckgeschwindigkeit in Drucke/Stunde (print/hour); entspricht der Anzahl der Umdrehungen der Farbwerkswalze 4 pro Stunde

k

Glättwalzen-Positionsfaktor, der von der Position der jeweiligen Glättwalze in der nach der Schwingrakel 3 beginnenden Walzenreihe abhängt und sich wertmäßig von Glättwalze zu Glättwalze verdoppelt, d. h.: k = 1 für erste Glättwalze 5.1 k = 2 für zweite Glättwalze 5.2 k = 4 für dritte Glättwalze 5.3 usw.

n'

Substitutionswert, der sich aus dem Ergebnis n der Funktion n = 3600·d·f / D·v

ergibt, wobei die Übertragungszahl n die Anzahl der entlang des Umfangs der jeweiligen Glättwalze gleichzeitig aufnehmbaren Farbspaltungshäufchen 24 beschreibt und n' diejenige Zahl mit der Zehnteldezimalstelle ”5” ist, welche Zahl der Übertragungszahl strikt nach oben gezählt (vgl. 4) oder strikt nach unten gezählt (vgl. 5) oder nach oben und unten gezählt (vgl. 6) am nächsten liegt.The symbols have the following meaning:

S [%]

Slip of the respective smoothing roll 5.1 to 5.3

d [mm]

Diameter of the respective smoothing roll 5.1 to 5.3

f [Hz]

Frequency of vibration of the vibrating squeegee 3

D [mm]

Diameter of the ink fountain roller 4

v [p / h]

Print speed in prints / hour (print / hour); corresponds to the number of revolutions of the inking roller 4 per hour

k

Smoothing roller position factor, which depends on the position of the respective smoothing roller in the after the squeegee 3 Depends on the beginning of rolling row and doubling in terms of value of smoothing roll to smoothing roll, ie: k = 1 for first smoothing roll 5.1 k = 2 for second smoothing roll 5.2 k = 4 for third smoothing roll 5.3 etc.

n '

Substitution value resulting from the result n of the function n = 3600 · d · f / D · v

wherein the transference number n is the number of ink splitting clutches which can be simultaneously received along the circumference of the respective smoothing roller 24 describes and n 'is the number with the tenth of decimal place "5", which number of the transmission number strictly up counted (see. 4 ) or strictly counted down (cf. 5 ) or counted up and down (cf. 6 ) is closest.

The slip characteristics for the first smoothing roll 5.1 showing diagrams of 4 to 7 the following dimensions and parameters are used:
D = 270 mm
d = 60 mm
f = 0 Hz to 200 Hz

The diagrams of the 4 to 6 the printing speed is based on v = 6000 p / h.

In 4 a variant of the slip characteristic is shown, in which the first smoothing roll 5.1 with slower surface speed than the inking roller 4 Consequently, the slip S in the entire frequency band passed through is not greater than zero, the slip S being predominantly negative and zero at certain frequencies. At these frequencies no slip S is required because the diameters D and D of the rollers 4 and 5.1 already matched to one another such that at the respective frequency the Farbspaltungshäufchen 24 exactly in the middle between the color piles 20 in the valleys 21 to be placed. This phenomenon is repeated at a certain frequency spacing and for this reason, a so-called "sawtooth" of the slip characteristic, which increases with increasing frequency f of the vibrating squeegee 3 tends to zero. To the in 4 If the reproduced slip characteristic with "negative slip" is obtained, the substitution value n 'must be formed by strict "rounding-up" of the respective transmission number n to the smoothest one-tenth decimal point "5" with respect to this transmission number n. Accordingly, the transmission number n = 11 is replaced by the substitution value n '= 11.5 and the transmission number n = 11.28 is replaced by the substitution value n' = 11.5, and the transmission number n = 11.68 is substituted by the substitution value n '= 12.5 replaced.

In 5 a slip characteristic is shown, which instead of the slip characteristic off 4 Application can be found. In the 5 shown slip characteristic is obtained by replacing the transmission number n by the substitution value n ', which results from strictly "rounding off" the transmission number n to the n next to the transmission number n number with the smooth tenth decimal "5". For this purpose, for example, n = 11 is replaced by n '= 10.5 and n = 11.28 is replaced by n' = 10.5 and n = 11.68 is replaced by n '= 11.5. In the 5 Slip characteristic shown represents so-called "positive slip", in which the first smoothing roll 5.1 with faster surface speed than the inking roller 4 rotates.

In 6 a further variant of the slip characteristic is shown, which further variant with regard to a minimization of the slip and consequently with respect to a minimization of the engine 6 the first smoothing roll 5.1 applied drive power is advantageous and is therefore preferred. At the in 6 reproduced slip characteristic with "positive and negative slip" is the first smoothing roll 5.1 at certain frequencies with positive slip, at other frequencies with negative slip and at other frequencies without slippage to the ink fountain roller 4 from the engine 6 driven. In order to obtain the corresponding slip characteristic, the following case distinction must be made in the calculation of the substitution value n ': For the calculation of the substitution value n', the transmission number n is rounded up to the next higher number with the "tenths of decimal place" and in the other case or at a different frequency, rounded down to the next lower number with the "5" tenth of decimal, depending on whether the difference between the transmission number and said next higher number or the difference between the transmission number n and said next lower number is smaller: For example, n = 11 is rounded up to n '= 11.5, and n = 11.28 is rounded up to n' = 11.5, and n = 11.68 is rounded off to n '= 11.5.

The slip characteristics change depending on the machine speed or printing speed v. In 7 is a diagram showing the change of in 6 shown slip characteristic as a function of taking place within a speed range v = 3000 p / h to 15000 p / h change in the printing speed v, which forms a third axis of the diagram shows. Such a three-dimensional coordinate system for determining the respective required slip S is for each smoothing roll 5.1 to 5.3 in the control device 15 deposited, z. B. stored. The three-dimensional coordinate systems for the automatic control of the slip S of the smoothing rollers 5.1 to 5.3 can be used as mathematical equations, tables of values or otherwise in the controller 15 be deposited.

LIST OF REFERENCE NUMBERS

1

press

2

Short inking

3

oscillating knife

4

Inking roller

5.1

first smoothing roll

5.2

second smoothing roll

5.3

third smoothing roll

6

engine

7

bearing bush

8th

narrow gear

9

wide gear

10

ring groove

11

eccentric

12

Traversing drive

13

side frame

14

encoders

15

control device

16

main engine

17

encoder

18

thick color film

19

vibrator

20

color pile

21

depression

22

color relief

23

thin color film

24

Ink splitting heap

25

nip

26

Color residual pile

27

modified color relief

28

further modified color relief

A

arrow

B

arrow

C

arrow

d

Diameter of the respective smoothing roll 5.1 to 5.3

D

Diameter of the ink fountain roller 4

f

Frequency of the vibrating squeegee 3

k

Smoothing rolls position factor

n

transmission speed

n '

substitution value

S

slippage

v

print speed

Claims (5)

Method for controlling a short inking unit ( 2 ) of a printing machine ( 1 ), wherein by means of a vibrating doctor blade ( 3 ) Printing ink as a color relief ( 22 ) on an inking roller ( 4 ) and then the color relief ( 22 ) by means of at least one smoothing roll ( 5.1 ) is leveled, characterized in that the smoothing roll ( 5.1 ) with slip (S) to the inking roller ( 4 ) is rotated, the size of the slip (S) depending on at least a vibration parameter of the vibration of the vibrating doctor blade ( 3 ) is controlled. A method according to claim 1, characterized in that the size of the slip (S) in dependence on the frequency (f) of the vibration of the vibrating doctor blade ( 3 ) is controlled. A method according to claim 1 or 2, characterized in that the size of the slip (S) in dependence on the duty cycle of the vibration of the vibrating doctor blade ( 3 ) is controlled. Method according to one of claims 1 to 3, characterized in that the smoothing roll ( 5.1 ) by splitting the color relief ( 22 ) from it Farbfaltungshäufchen ( 24 ) and the size of the slip (S) is controlled such that the smoothing roll ( 5.1 ) in the course of their further rotation, the color cleavage clusters ( 24 ) specifically in subsequent sinks ( 21 ) of the color relief. Printing machine ( 1 ), with a short inking unit ( 2 ) and a control device ( 15 ), characterized in that the control device ( 15 ) for controlling the short inking unit according to the method of any one of claims 1 to 4 ( 2 ) is trained.

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