EP0806294A2 - Method and device for adjusting the circumferential register in a rotary press comprising a forme cylinder with a printing sleeve - Google Patents

Abstract

The method uses a harmonic drive (22) controlled via a central control device (40) in dependence on the measured difference between the rotation of the printing plate sleeve and the printing machine rotation rate. The drive corrects the rotation of the plate cylinder (10) fitted with the printing plate sleeve, for eliminating the detected rotation difference. The rotation rate of the printing plate sleeve can be detected by optical detection of peripheral register markings, e.g. using the detected time interval between the detection of two successive register markings.

Description

The present invention relates to a method and a device according to the preamble of claims 1 and 11.

Printing presses include mechanisms for adjusting the circumferential register of one cylinder relative to another cylinder of the printing press. In roller rotary printing machines such adjustments are usually made on a plate cylinder to adjust the position of the plate cylinder relative to the associated blanket cylinder in the circumferential direction, the blanket cylinder z. B. is driven via a common drive shaft by the motor of the main drive of the printing press. This adjustment in the circumferential direction ensures exact registration of the printed images printed on both sides of the web in the surface and back printing machines printing from blanket to blanket. In multicolor printing machines, such an adjustment of the circumferential register ensures that the printed images are printed with a first color in one printing unit and with a second color in another printing unit.

In the prior art web-fed rotary printing presses with conventional printing plates clamped onto the plate cylinders, the circumferential register setting of each plate cylinder is carried out by means of a helical toothing or a helical gear which is axially movable on the pivot pin of the plate cylinder. Such a device is e.g. For example, see U.S. Patent No. 4,709,634, the entire contents of which are incorporated herein by reference. In addition to the circumferential register setting, the device of US Pat. 4,709,634 further a side register adjustment of the plate cylinder. However, since the axial movement of the helical gear on the pivot of the plate cylinder is limited, the angle of rotation of the plate cylinder is also limited. The circumferential register can therefore only be set within a limited range.

In some printing units known from the prior art, continuous printing plates in the form of sleeves are used, which are applied to the plate cylinder through an opening formed in one side wall of the printing unit housing, the plate cylinder being freely floating or floating in the other side wall of the housing. In these printing units, the sleeve-shaped printing plates tend to migrate on the plate cylinder body when the printing press is in operation. A printing press in which sleeve-shaped printing plates are used is e.g. For example, see U.S. Patent No. 4,913,048, the entire contents of which are incorporated herein by reference.

The migration of the sleeve-shaped printing plates on the plate cylinder body often causes register errors in the respective printing unit. Attempts have therefore been made to eliminate the migration of the sleeve-shaped printing plates by z. B. by pinning or otherwise fixing on the respective plate cylinder body. Since the sleeve-shaped printing plates are usually made of lightweight conventional plate material, such as. B. aluminum, there is a risk that they break or become cracked by being fixed by pins on the plate cylinder body, since the material is not strong enough to withstand the forces that arise during the rotation of the printing plate on the plate cylinder body.

In view of the above-mentioned disadvantages of the prior art, it is an object of the present invention to provide a method and a device with which the circumferential register in a web-fed rotary printing press with at least one printing unit containing a sleeve-shaped printing plate with high reliability and accuracy over an unlimited range Range can be set.

According to the invention, this object is achieved by the features of claims 1 and 11. Further features of the invention are contained in the subclaims.

According to the invention, in a method for setting the circumferential register in a web-fed rotary printing press with a plate cylinder carrying a sleeve-shaped printing plate on a plate cylinder body, a speed difference between the speed of the sleeve-shaped printing plate and the speed of the printing press is determined and the speed of the plate cylinder body carrying the sleeve-shaped printing plate is changed in such a way that the speed difference is reduced. In this case, the speed of the sleeve-shaped printing plate is advantageously carried out by detecting marks formed on the sleeve-shaped printing plate, for example register marks, the detection of the register marks on the sleeve-shaped printing plate preferably taking place optically. In addition, it can be provided that the speed of the sleeve-shaped printing plate is carried out indirectly by measuring a time difference between two successive detections of a register mark.

According to a further embodiment of the invention, the speed of the printing press is preferably determined by an angle encoder or angle encoder, which can be connected, for example, to a blanket cylinder assigned to the plate cylinder. In addition, it can also be provided to determine the speed of the printing press by detection of register marks which are formed on the body of a blanket cylinder assigned to the plate cylinder, the detection of the register marks on the body of the blanket cylinder advantageously taking place optically and e.g. B. indirectly by measuring a time difference between two successive detections of the register mark on the body of the blanket cylinder.

According to a further embodiment of the method according to the invention, the speed of the sleeve-shaped pressure plate can be achieved by differentiating a measured position signal.

According to the invention also has a device for setting a circumferential register in a web-fed rotary printing press with a sleeve-shaped one Printing plate on a plate cylinder body-carrying plate cylinder, a first detector for detecting the speed of the sleeve-shaped printing plate, a second detector for detecting the speed of the printing press and a speed control device which determines the speed of the plate-shaped cylinder body carrying the sleeve-shaped printing plate as a function of the speed difference between the through the first detector and controls the second detector of detected speeds such that the speed difference is reduced or minimized.

Here, the first detector can be, for example, an optical detector which detects a mark arranged on the sleeve-shaped printing plate and, for example, indirectly determines the speed of the sleeve-shaped printing plate by measuring the time difference between two successive detections of the mark. There is also the possibility that the second detector is an angle encoder or angle encoder, which is connected to the body of a blanket cylinder assigned to the plate cylinder.

According to a further embodiment of the invention, the second detector can be a detector which detects marks formed on a blanket cylinder assigned to the plate cylinder, the marks on the blanket cylinder advantageously being able to be optically scanned and the second detector measuring the speed of the printing press, for example indirectly, by measuring a time difference determined between two successive detections of the marks on the blanket cylinder.

According to a further preferred embodiment of the invention, the speed control device comprises a speed-adjustable adjustment gear connected to the plate cylinder.

Finally, it can be provided that the speed control device has individual drives which drive the plate cylinder and / or the associated blanket cylinder separately.

The method according to the invention and the device according to the invention have the advantage that the setting of the circumferential register can be carried out continuously during the operation of the printing press. It is a further advantage of the present invention that the setting of the circumferential register is not limited to a certain angular range. In addition, the circumferential register setting according to the invention is carried out automatically and does not require any additional actions by the operator.

Further advantages and features of the present invention are explained in more detail in the following description of preferred exemplary embodiments in conjunction with the accompanying drawings explained below:

Fig. 1

einen schematischen Querschnitt eines Druckwerks mit einem Gummituchzylinder und einem zugeordneten Plattenzylinder, der eine hülsenförmige Druckplatte trägt sowie mit einem Registereinstellsystem nach einem Ausführungsbeispiel der vorliegenden Erfindung; und

Fig. 2

eine schematische Seitenansicht des Druckwerks der Fig. 1, in welchem die Geschwindigkeit des Gummituchzylinders durch optische Detektoren und entsprechende Marken auf dem Gummituchzylinder erfaßt wird.

Show it

Fig. 1

a schematic cross section of a printing unit with a blanket cylinder and an associated plate cylinder, which carries a sleeve-shaped printing plate and with a register adjustment system according to an embodiment of the present invention; and

Fig. 2

a schematic side view of the printing unit of Fig. 1, in which the speed of the blanket cylinder is detected by optical detectors and corresponding marks on the blanket cylinder.

The printing unit 1 shown in Fig. 1 comprises a housing 2, in which a blanket cylinder 4 and an associated plate cylinder 6 are rotatably received with their pivot pins in respective bearings. A further cylinder 8 can be rotatably mounted in the housing 2 under the blanket cylinder 4. The cylinder 8 can either be a printing cylinder or, in the case of a perfecting press with rubber-to-rubber printing units, a second blanket cylinder which is assigned to a platter cylinder, not shown. Of the Plate cylinder 6 has a plate cylinder body 10 on which a sleeve-shaped pressure plate 12 is attached. The pressure plate 12 may e.g. B. be formed from a conventional printing plate by bending the plate into a sleeve and welding the ends of the plate together or by means of adhesive or in some other way. Alternatively, the printing plate can be formed from a seamless tube, to which the printed image is subsequently transferred.

The sleeve-shaped printing plate 12 - hereinafter also called the printing plate sleeve - is applied to and held by the plate cylinder body 10 by moving the printing plate 12 laterally through an opening 14 formed in the left side wall 2a of the housing 2 of the printing unit on the plate cylinder body 10. Here, the plate cylinder 6 is overhung in the right side wall 2b of the housing 2 of the printing unit, as z. As described in U.S. Patent No. 4,913,048, the entire contents of which are incorporated herein by reference. In order to ensure a secure and precise attachment of the printing plate to the plate cylinder 10, the inside diameter of the printing plate sleeve 12 is slightly smaller than the outside diameter of the plate cylinder body 10.

When the pressure plate sleeve 12 is applied to the plate cylinder body 10, the sleeve is expanded by compressed air supplied through air nozzles (not shown) built in the peripheral surface of the plate cylinder body 10. By turning off the compressed air, the pressure plate sleeve 12 is clamped onto the plate cylinder body 10, as is the case, for. For example, see U.S. Patents 4,903,597 and 4,913,048, the entire contents of which are incorporated herein by reference.

Although this clamping of the printing plate sleeve 12 causes a relatively firm and secure fit of the printing plate sleeve 12 on the plate cylinder body 10, the printing plate sleeve 12 can move and migrate relative to the plate cylinder body 10 during operation of the printing unit, which continuously causes the printing unit 1 to be incorrectly registered. The speed at which the printing plate sleeve 12 moves or moves on the plate cylinder body 10 depends on the Machine speed and can, for. B. be one revolution per day when the machine is running at a speed of approximately 80,000 revolutions per hour. The speed of the relative movement between the plate cylinder body 10 and the pressure plate sleeve 12 is dependent on various factors, such as. B. the machine speed, the temperature of the cylinders, the surface structure of the plate cylinder body 10, the surface structure of the printing plate sleeve 12, the rubber material on the blanket cylinder 4, the force with which the plate cylinder 6 and the blanket cylinder 4 are pressed against each other, the printing plate material, the different Clamping forces of the sleeve on the cylinder, etc. affected.

Harmonic Getriebe" (harmonic drive) sein kann, wie es z. B. in den US-Patenten Nr. 3,724,368 und Nr. 2,906,143 beschrieben ist, auf deren gesamten Inhalt hier Bezug genommen wird. Das geschwindigkeitsregelbare Verstellgetriebe 22 verbindet antriebsmäßig die Antriebswelle oder den Drehzapfen 24 des Plattenzylinders 6 mit einer Welle 26 , mit welcher wiederum ein schrägverzahntes Antriebsrad 28 axial drehbar verbunden ist. Das geschwindigkeitsregelbare Verstellgetriebe 22 sorgt für eine geringfügige Geschwindigkeitsdifferenz zwischen der Welle 26 und der Antriebswelle 24 des Plattenzylinders 6 und ermöglicht eine sehr feine und genaue Einstellung dieser Geschwindigkeitsdifferenz. Das Verstellgetriebe 22 kann durch einen Elektromotor, z. B. einen Schrittmotor 30, der einen Wellenerzeuger 32 des Verstellgetriebes 22, z. B. über eine sich durch die Mitte der Welle 26 erstreckende Welle 34 dreht, oder einen anderen bekannten motorischen Antrieb betätigt werden. Wenn die Welle 34 gedreht wird, erzeugt das Verstellgetriebe 22 eine Geschwindigkeitsdifferenz zwischen der Welle 26 und der Antriebswelle oder dem Drehzapfen 24 des Plattenzylinders 6, so daß der Plattenzylinderkörper 10 bezüglich der mit Maschinengeschwindigkeit angetriebenen Welle 26 mit einer geringfügig höheren Geschwindigkeit angetrieben wird. Die Welle 26 wird durch das Plattenzylinderzahnrad 28, das mit dem Gummituchzylinderzahnrad 36 kämmt, angetrieben, wobei das Gummituchzylinderzahnrad 36, durch den Hauptantrieb 38 der Druckmaschine z. B. mit Maschinengeschwindigkeit angetrieben wird.In order to compensate for the incorrect registration of the printing unit 1 caused by the migration of the printing plate sleeve 12, a dynamic circumferential register setting system 20 according to the invention is provided. This dynamic register setting system 20 comprises a speed-adjustable adjusting gear 22, which is, for example, a so-called

Harmonic drive ", as described, for example, in US Pat. Nos. 3,724,368 and 2,906,143, the entire contents of which are hereby incorporated by reference. The variable-speed adjustment mechanism 22 drives the drive shaft or the drive Trunnion 24 of the plate cylinder 6 with a shaft 26, with which in turn an helically toothed drive wheel 28 is axially rotatably connected The variable speed gear 22 may be driven by an electric motor, such as a stepper motor 30, that rotates a shaft generator 32 of the variable speed gear 22, such as a shaft 34 that extends through the center of the shaft 26, or by another known motor Drive are actuated when shaft 34 is pressed eht, the adjusting gear 22 generates a speed difference between the shaft 26 and the drive shaft or the pivot 24 of the plate cylinder 6, so that the plate cylinder body 10 with respect to the shaft 26 driven at machine speed with a slightly higher Speed is driven. The shaft 26 is driven by the plate cylinder gear 28, which meshes with the blanket cylinder gear 36, the blanket cylinder gear 36, by the main drive 38 of the printing machine, for. B. is driven at machine speed.

To control the speed of the plate cylinder body 10, the dynamic register setting system 20 comprises a central control device 40 which controls the speed and the direction of rotation of the stepping motor 30. The central control device 40 is also electrically connected to a first detector 42, which can be attached to the surface of the printing plate sleeve 12. The first detector 42 is preferably an optical sensor, the brands such. B. the register marks provided on the side of a printing plate for the usual static circumferential and / or page register setting. However, the detector 42 is not limited to the scanning of register marks, but can in the same way be a detector for scanning a certain area within the printed image recorded on the printing plate or an electrically, magnetically or mechanically actuated sensor.

A second detector 44 for measuring the speed of the printing press is also connected to the central control device 40. The second detector 44 can e.g. B. a conventional rotary encoder or encoder, which is connected to the drive shaft 46 or the pivot of the blanket cylinder 4 and the central control device 40 supplies a signal which corresponds to the speed of the printing press or the printing unit 1. An active encoder can e.g. B. When using a continuous sleeve-shaped rubber blanket, as described in US Patent No. 5,429,048, the entire contents of which are incorporated herein by reference. As indicated therein, the sleeve-shaped blanket is applied to the blanket cylinder body in the same manner as the printing plate sleeve 12 is applied to the plate cylinder body 10. Thus, the sleeve-shaped rubber blanket also migrates on the rubber blanket cylinder body during the operation of the printing press.

As shown in FIG. 2, the second detector 44 can also be an optical detector which optically scans marks provided on the blanket cylinder 4 in the same way as the first detector 42. In a further embodiment of the invention, the second detector 44 z. B. can also be provided on the main machine drive, on a further printing unit, on the central drive shaft of the machine or at another possible location where the machine speed can be measured. The second detector 44 is not limited to an optical sensor, but can also be an electrically, magnetically or mechanically actuated or other suitable sensor.

The first and second detectors 42, 44 generate corresponding first and second signals, each of which corresponds to the speed of the printing plate sleeve 12 and the speed of the printing press or printing unit 1. The first and the second signal are evaluated by the central control device 40. The central control device 40 generates a control signal for the stepper motor 30 of the speed-adjustable adjusting gear 22 on the basis of the speed difference between the speed of the printing plate sleeve 12 measured by the first detector 42 and the speed of the printing press measured by the second detector 44. The central control device 40 controls the stepper motor 30 in such a way that the adjusting mechanism 22 produces a slight overspeed of the plate cylinder body 10 and minimizes the speed difference between the speed of the printing plate sleeve 12 measured by the first detector 42 and the speed of the printing press measured by the second detector 44 and / or reduced to zero.

Micro Track CCR" (Januar 1990) beschrieben. Auf den Inhalt dieses Handbuches, das vom genannten Hersteller erhältlich ist, wird hier Bezug genommen.The hardware used for the central control device 40 and the first and second detectors 42, 44 can e.g. B. A commercially available register control system for controlling the dynamic range and page register in a web-fed rotary press. Such a system is e.g. B. is manufactured and sold by Web Printing Controls Co., Inc., 23872 N. Kelsey Road, Lake Barrington, Illinois 60010-1653, USA and is used in the printing presses manufactured by the applicant of the M3000 series. The control system of the above manufacturer is entitled in a manual distributed by Web Printing Controls

Micro Track CCR "(January 1990). The content of this manual, which is available from the named manufacturer, is referred to here.

In addition, a commonly used static size and page register setting system for controlling the static size and page register independently of the above-mentioned dynamic size register setting, such as e.g. For example, the system described in U.S. Patent No. 4,709,634, the contents of which are incorporated herein by reference. In Fig. 1, the static circumferential register adjustment of the plate cylinder 6 is shown by a double arrow 48 to adjust the static circumferential register adjustment of the plate cylinder 6 by axial movement of the to indicate diagonally toothed gear 28 on the shaft 26, which is rotated with respect to the drive shaft 46 of the blanket cylinder 4.

The speed signals generated by the first and second detectors 42, 44 can be signals that correspond to a surface speed, such as e.g. B. correspond to the surface speed of the printing plate sleeve 12 and / or the blanket cylinder 4 and / or can be signals which correspond to an angular velocity, e.g. B. the angular velocity of the shaft 46 of the blanket cylinder 4, and / or may be signals that correspond to a time difference between two successive scans of a mark on the printing plate sleeve 12 or on the blanket cylinder 4. Variations and alternative types of speed signals suitable for the exemplary embodiments according to the invention are obvious to the person skilled in the art.

The signals can e.g. B. also by measurement and differentiation of relative positions of locations or marks on the printing plate sleeve 12 and an associated reference point or mark (z. B. on a drive shaft or a blanket cylinder) can be obtained. In this case, the two digits or stamps on each Rotation of the cylinders held in the same position by changing and adjusting the speed as described above.

In printing units in which each cylinder is driven separately by a respective individual motor, e.g. B. by direct drive electric motors 52 and 54 shown as dashed lines in FIG. 1, the dynamic register setting can be carried out either in the manner described above or by a direct control of the relative speed of the motors. For example, a dynamic setting of the register can be achieved in that the individual drive motor of the plate cylinder 6 or the plate cylinder is controlled via the central control device 40. In this case, a speed-adjustable adjusting gear 22 is not necessary. The gears 28 and 36 are then also not required.

LIST OF REFERENCES

1

Printing unit

2nd

casing

2a

left side wall of the housing 2

2 B

right side wall of the housing 2

4th

Blanket cylinder

6

Plate cylinder

8th

cylinder

10th

Plate cylinder body

12th

sleeve-shaped pressure plate / pressure plate sleeve

14

Opening in the printing unit housing 2

20th

dynamic range register adjustment system

22

speed-adjustable adjustment gear

24th

Drive shaft or rotary pivots of the plate cylinder 6

26

wave

28

helical drive wheel of the plate cylinder 6

30th

Stepper motor

32

Shaft generator of the adjusting gear 22

34

wave

36

Blanket cylinder gear

38

Main drive of the printing press

40

central control device

42

first detector

44

second detector

46

Drive shaft or pivot pin of the blanket cylinder 4

48

Double arrow

52

Direct drive electric motor

54

Direct drive electric motor

Claims (19)

Method for setting the circumferential register in a web-fed rotary printing press with a plate cylinder carrying a sleeve-shaped printing plate on a plate cylinder body, characterized by the following method steps:
Determining a speed difference between the speed of the sleeve-shaped printing plate and the speed of the printing press, and
Changing the speed of the plate cylinder body carrying the sleeve-shaped pressure plate in such a way that the speed difference is reduced. Method according to claim 1,
characterized,
that the speed of the sleeve-shaped printing plate is carried out by detection of register marks formed on the sleeve-shaped printing plate. Method according to claim 2,
characterized,
that the detection of the register marks on the sleeve-shaped printing plate is carried out optically. Method according to claim 2,
characterized,
that the speed of the sleeve-shaped printing plate is carried out by measuring a time difference between two successive detections of a register mark. Method according to one of the preceding claims,
characterized,
that the speed of the printing press is determined by an angle encoder. Method according to claim 5,
characterized,
that the encoder is connected to a blanket cylinder assigned to the plate cylinder. Method according to one of the preceding claims,
characterized,
that the speed of the printing machine is carried out by detection of register marks which are formed on the body of a blanket cylinder assigned to the plate cylinder. Method according to claim 7,
characterized,
that the detection of the register marks on the body of the blanket cylinder takes place optically. Method according to claim 7,
characterized,
that the speed of the printing press is determined by measuring a time difference between two successive detections of the register mark on the body of the blanket cylinder. Method according to claim 1,
characterized,
that the speed of the sleeve-shaped pressure plate (12) by differentiation a measured position signal. Device for setting a circumferential register in a web-fed rotary printing press with a plate cylinder (6) carrying a sleeve-shaped printing plate (12) on a plate cylinder body (10),
marked by a first detector (42) for detecting the speed of the sleeve-shaped pressure plate (12); a second detector (44) for detecting the speed of the printing press, and a speed control device (40) which controls the speed of the plate cylinder body (10) carrying the sleeve-shaped pressure plate (12) in dependence on the speed difference between the speeds detected by the first detector (42) and the second detector (44) in such a way that the speed difference is reduced. Device according to claim 11,
characterized,
that the first detector (42) is an optical detector which detects a mark arranged on the sleeve-shaped printing plate (12). Device according to claim 12,
characterized,
that the first detector (42) indirectly determines the speed of the sleeve-shaped pressure plate (12) by measuring the time difference between two successive detections of the mark. Device according to one of the preceding claims,
characterized,
that the second detector (44) is an angular encoder which with the body of one Plate cylinder (6) associated blanket cylinder (4) is connected. Device according to one of the preceding claims,
characterized,
that the second detector (44) is a detector which detects marks formed on a blanket cylinder (4) associated with the blanket cylinder (6). Device according to claim 15,
characterized,
that the marks on the blanket cylinder (4) are optically scanned. Device according to claim 15,
characterized,
that the second detector (44) indirectly determines the speed of the printing press by measuring a time difference between two successive detections of the marks on the blanket cylinder (4). Device according to one of claims 11 to 17,
characterized,
that the speed control device (40) comprises a speed-adjustable adjustment gear (22) connected to the plate cylinder (6). Device according to one of claims 11 to 18,
characterized,
that the speed control device (40) comprises individual drives which drive the plate cylinder (6) and / or the associated blanket cylinder (4) separately.

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