CA2375431A1 - Method for a driving a printing press - Google Patents
Method for a driving a printing press Download PDFInfo
- Publication number
- CA2375431A1 CA2375431A1 CA 2375431 CA2375431A CA2375431A1 CA 2375431 A1 CA2375431 A1 CA 2375431A1 CA 2375431 CA2375431 CA 2375431 CA 2375431 A CA2375431 A CA 2375431A CA 2375431 A1 CA2375431 A1 CA 2375431A1
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- CA
- Canada
- Prior art keywords
- printing
- form cylinder
- cylinder
- drive
- driving
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
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- Inking, Control Or Cleaning Of Printing Machines (AREA)
- Rotary Presses (AREA)
Abstract
A printing press which is equipped with a device for producing a printing form in the printing press is driven during the print operation by a motor, which drives a drum for advancing the printing material and drives a printing-form cylinder. In the production of the printing form, the printing-form cylinder is driven by a second, separate motor in such a way that a gear which is allocated to the drive of the printing-form cylinder and an adjacent gear which is allocated to the drive of the drum do not touch, or these exert slight pressure on each other.
Description
METHOD FOR DRIVING A PRINTING PRESS
The invention relates to a method for driving a printing press, particularly a sheet-fed press having an integrated device for producing a printing form.
There are known printing presses in which laser imaging heads are allocated to the printing-form cylinders, with which image points that accept ink are generated on a printing plate or a printing form within the printing press. A variety of disturbances act on the imaging process, influencing the position of the image points on the printing plate or printing form. The printing-form cylinder is rotated during the imaging process, it being possible to capture the entire surface by guiding an imaging head parallel to the axis of rotation of the printing-form cylinder. The slightest mechanical vibrations and impacts acting on the system of the printing-form cylinder and the imaging head cause imaging errors that cannot be corrected without further ado.
DE 692 22 035 T2 teaches a method whereby unroundnesses of a printing-form cylinder are corrected by controlling the time of an imaging process point by point. DE 692 22 801 T2 describes a solution in which a correction value is assigned to each image point to be set. In this way, corrections can be made in both the circumferential and lateral directions of a printing-form cylinder. It is possible to compensate periodic and predictable noise quantities with such software-based methods. Disturbances due to high-frequency vibrations and impacts can only be inadequately compensated owing to the limited signal processing speed of a computer.
DE 197 23 147 Al teaches a method for driving a printing press having an integrated imaging device whereby the drive of the printing-form cylinder is decoupled from the drive train, the printing-form cylinder is driven by a separate drive in the imaging operation, and following the imaging operation the drive of the printing-form cylinder is reintegrated into the drive train in the phase angle of operation. The decoupling of the printing-form cylinder is intended to prevent influences of the drive train on the imaging process. This decoupling is an intensive process owing to the required clutch.
DE 198 22 893 Al teaches a solution whereby all non-uniformly rotating subassemblies of a printing press are decoupled from the printing-form cylinder drive, and all uniformly rotating subassemblies are driven together with the printing-form cylinder. Besides one or more clutches, powerful motors are needed for the drive of the printing-form cylinder and the uniformly moving groups.
To prevent print disturbances, DE 196 23 224 C1 describes a drive for a sheet-fed press wherein printing-unit cylinders can be driven while mechanically decoupled from the gear train of the sheet transfer system. The separate driving of, for instance, a plate cylinder is intended to prevent the effects of load fluctuations in the gear train of the sheet transfer system on the plate cylinder during the print operation. The separate driving of a plate cylinder additionally makes it possible to correct the circumferential register and the print length and to improve the flexibility, because plate exchange and washing processes can run in unoccupied printing units during the print operation. The angle synchronicity between plate cylinders and the sheet transfer system must be realized by an intensive control.
The invention relates to a method for driving a printing press, particularly a sheet-fed press having an integrated device for producing a printing form.
There are known printing presses in which laser imaging heads are allocated to the printing-form cylinders, with which image points that accept ink are generated on a printing plate or a printing form within the printing press. A variety of disturbances act on the imaging process, influencing the position of the image points on the printing plate or printing form. The printing-form cylinder is rotated during the imaging process, it being possible to capture the entire surface by guiding an imaging head parallel to the axis of rotation of the printing-form cylinder. The slightest mechanical vibrations and impacts acting on the system of the printing-form cylinder and the imaging head cause imaging errors that cannot be corrected without further ado.
DE 692 22 035 T2 teaches a method whereby unroundnesses of a printing-form cylinder are corrected by controlling the time of an imaging process point by point. DE 692 22 801 T2 describes a solution in which a correction value is assigned to each image point to be set. In this way, corrections can be made in both the circumferential and lateral directions of a printing-form cylinder. It is possible to compensate periodic and predictable noise quantities with such software-based methods. Disturbances due to high-frequency vibrations and impacts can only be inadequately compensated owing to the limited signal processing speed of a computer.
DE 197 23 147 Al teaches a method for driving a printing press having an integrated imaging device whereby the drive of the printing-form cylinder is decoupled from the drive train, the printing-form cylinder is driven by a separate drive in the imaging operation, and following the imaging operation the drive of the printing-form cylinder is reintegrated into the drive train in the phase angle of operation. The decoupling of the printing-form cylinder is intended to prevent influences of the drive train on the imaging process. This decoupling is an intensive process owing to the required clutch.
DE 198 22 893 Al teaches a solution whereby all non-uniformly rotating subassemblies of a printing press are decoupled from the printing-form cylinder drive, and all uniformly rotating subassemblies are driven together with the printing-form cylinder. Besides one or more clutches, powerful motors are needed for the drive of the printing-form cylinder and the uniformly moving groups.
To prevent print disturbances, DE 196 23 224 C1 describes a drive for a sheet-fed press wherein printing-unit cylinders can be driven while mechanically decoupled from the gear train of the sheet transfer system. The separate driving of, for instance, a plate cylinder is intended to prevent the effects of load fluctuations in the gear train of the sheet transfer system on the plate cylinder during the print operation. The separate driving of a plate cylinder additionally makes it possible to correct the circumferential register and the print length and to improve the flexibility, because plate exchange and washing processes can run in unoccupied printing units during the print operation. The angle synchronicity between plate cylinders and the sheet transfer system must be realized by an intensive control.
It is the object of the invention to develop a drive concept for a printing press with an integrated imaging device which makes possible both the print operation and a faultless imaging operation, with little outlay.
The object is achieved by a method with the features of patent claim 1. A printing press with the features of claim 3 is suitable for this method. Advantageous developments derive from the subclaims.
The basis of the invention is that, by means of a control device for a printing press drive, a motor for driving a printing-form cylinder is so actuated relative to the main drive train of the press in the imaging operation that no contact of tooth flanks occurs between the gears driving the printing-form cylinder and those powering the main drive train. Thus, no torsional vibrations are transferred to the main printing-form cylinder from the main drive train. This improves the quality of the imaging of the printing-form cylinder.
Using the method, a printing press can be so constructed that in the print operation it is driven by one or more motors that are coupled to the main drive train. The separate motor for driving the printing-form cylinder can be deactivated in the print operation or can act as an auxiliary drive to secure the contact of the tooth flanks and/or to prevent print disturbances. In the imaging operation, both motors are controlled by one control device. Unlike in the print operation, in order to prevent the transference of vibrations to the printing-form cylinder, the tooth flank contact between two gears, which are allocated to the main drive train and the secondary drive train for driving the printing-form cylinder, respectively, is prevented. The main drive train and the secondary drive train are advantageously driven in such a way that the gears which are allocated to the transfer cylinder and the printing-form cylinder do not touch each other. It is advantageous when signals indicating the angle of rotation and the torsional vibrations of the transfer cylinder are acquired using a rotary position transducer and processed in the control device. Clutches for separating from the main drive train and the secondary drive train can be forgone. Because the gear train in the printing press does not have to be disengaged, it is guaranteed that the angle position will not be shifted by clutching and declutching operations.
The invention will now be detailed with reference to an exemplifying embodiment, which shows:
Figure l: a schematic of a printing press;
Figure 2: a schematic of a drive;
Figure 3: a gear pair in the print operation; and Figure 4: a gear pair in the imaging operation.
Figure 1 shows the schematic of a two-color sheet-fed printing press. The printing press contains two printing units 1, 2 in series, a feeder 3, and a delivery 4. The feeder 3 contains a sheet stack 5, a singularizer 6, a feed table, and feed devices 8, 9. In each printing unit l, 2 there is an impression cylinder 10, 11, a transfer cylinder 12, 13, a printing-form cylinder 14, 15, a wetting unit 16, 17 and an inking unit 18, 19. The impression cylinders 10, 11 of the printing units 1, 2 are connected to a transfer drum 20, a storage drum 21, and a reversing drum 22. The delivery 4 contains a chain gripper system 23 and a sheet stack 24. To produce a printing form inside the printing press, an imaging head 25, 26 is allocated to each printing-form cylinder 14, 15. The elements 6, 8, and 9 of the feeder 3, which advance the sheet 27; the cylinders 10, 11, 12, 13, 14, 15, 20, 21, and 22 in and between the printing units l, 2; the driven rollers of the inking and wetting units 16-19; and the elements 27 of the delivery 4, which advance the sheet 23, are connected to each other by way of a common gear train and are driven by a main drive motor 28. The printing-form cylinders 14, 15 can also be driven with secondary drive motors 29, 30.
Rotary position transducers 31, 32 are provided at the transfer cylinders 12, 13 for detecting the angle of rotation.
A control device 33 is connected to the rotary position transducers 31, 32 for the signal input and to the main drive motor 28, the secondary drive motors 29, 30 and the imaging heads 25, 26 for the signal output. The control device 33 also receives signals from an image data storage unit.
Figure 2 shows the details of the drive of the printing press more closely. Figure 2 shows the printing-form cylinder 14 and the transfer cylinder 12, which are held in a sidewall 39 of the press with their pins 35, 36 in bearings 37, 38. Gears 40, 41 are secured on the pins 35, 36. The gears 40, 41, together with other gears 42, belong to a closed gear train, which is coupled to the main drive motor 28. For the separate driving of the printing-form cylinder 14, a secondary drive motor 29 is provided, whose motor shaft 43 is connected to the gear 40.
The secondary drive motor 29 is secured in a holding device 44. To detect the angle of rotation of the transfer cylinder 12, a rotary position transducer 45 is secured in the holding device 44, with the transducer shaft 46 thereof being connected to the gear 41. A control line 47 leads from the control device 33 to the secondary drive motor 29. The rotary position transducer 45 is connected to the control device 33 via a signal line 48. The drive is constructed equivalently in the printing unit 2.
Figures 3 and 4 illustrate the functioning of the drive system. In the print operation, the drive system operates in a first mode. The drive train is operated such that the tooth flanks of the gears 40, 41, i.e. those of the corresponding gears of the transfer cylinders 13 [sic] and the printing-form cylinder 15 in the printing unit 2 as represented in Figure 3, touch each other. The tooth flank contact is continuously maintained during the print operation in order to prevent doubling phenomena. Expediently, the secondary drive motor 29 can also be operated so as to exert a slight braking influence, so that the tooth flank contact is also maintained given sharp load fluctuations.
In the imaging operation, the drive system 14 operates in a second mode. As represented in Figure 4, the printing-form cylinders 14 and 15 are driven by the secondary drive motor 29 and 30, respectively, in such a way that the tooth flank contact of the gears 40, 41, i.e. of the corresponding gears of the transfer cylinder 13 and the impression cylinder 15 in the printing unit 2, is eliminated or is so slight that no mechanical disturbances are transferred to the printing-form cylindersl4 and 15 via the drive train. It is also possible for part of the gears belonging to the respective inking units 18, 19, or wetting units 16, 17, respectively, to be driven via the secondary drive motors 29, 30. In order to eliminate the tooth flank contact or reduce it to a harmless scale, the actual values of the angle of rotation and the torsional vibrations that are present at the respective transfer cylinder 12, 13 are continuously fed to the control device 33 via the signal line 48. These signals are processed in the control device 33 into actuating signals for the main drive motor 29 and the secondary drive motors 29 and 30. The control of the angle synchronicity of the gears 41, 42 of the main drive train relative to the gears 40 of the secondary drive train is dynamic enough to reliably prevent tooth flank contact between the gears 40, 41.
In a variant of the invention, it would be possible to additionally process signals from additional rotary positional transducers, which are coupled with the rotation of the printing-form cylinders 14, 15, in the control device 33.
The object is achieved by a method with the features of patent claim 1. A printing press with the features of claim 3 is suitable for this method. Advantageous developments derive from the subclaims.
The basis of the invention is that, by means of a control device for a printing press drive, a motor for driving a printing-form cylinder is so actuated relative to the main drive train of the press in the imaging operation that no contact of tooth flanks occurs between the gears driving the printing-form cylinder and those powering the main drive train. Thus, no torsional vibrations are transferred to the main printing-form cylinder from the main drive train. This improves the quality of the imaging of the printing-form cylinder.
Using the method, a printing press can be so constructed that in the print operation it is driven by one or more motors that are coupled to the main drive train. The separate motor for driving the printing-form cylinder can be deactivated in the print operation or can act as an auxiliary drive to secure the contact of the tooth flanks and/or to prevent print disturbances. In the imaging operation, both motors are controlled by one control device. Unlike in the print operation, in order to prevent the transference of vibrations to the printing-form cylinder, the tooth flank contact between two gears, which are allocated to the main drive train and the secondary drive train for driving the printing-form cylinder, respectively, is prevented. The main drive train and the secondary drive train are advantageously driven in such a way that the gears which are allocated to the transfer cylinder and the printing-form cylinder do not touch each other. It is advantageous when signals indicating the angle of rotation and the torsional vibrations of the transfer cylinder are acquired using a rotary position transducer and processed in the control device. Clutches for separating from the main drive train and the secondary drive train can be forgone. Because the gear train in the printing press does not have to be disengaged, it is guaranteed that the angle position will not be shifted by clutching and declutching operations.
The invention will now be detailed with reference to an exemplifying embodiment, which shows:
Figure l: a schematic of a printing press;
Figure 2: a schematic of a drive;
Figure 3: a gear pair in the print operation; and Figure 4: a gear pair in the imaging operation.
Figure 1 shows the schematic of a two-color sheet-fed printing press. The printing press contains two printing units 1, 2 in series, a feeder 3, and a delivery 4. The feeder 3 contains a sheet stack 5, a singularizer 6, a feed table, and feed devices 8, 9. In each printing unit l, 2 there is an impression cylinder 10, 11, a transfer cylinder 12, 13, a printing-form cylinder 14, 15, a wetting unit 16, 17 and an inking unit 18, 19. The impression cylinders 10, 11 of the printing units 1, 2 are connected to a transfer drum 20, a storage drum 21, and a reversing drum 22. The delivery 4 contains a chain gripper system 23 and a sheet stack 24. To produce a printing form inside the printing press, an imaging head 25, 26 is allocated to each printing-form cylinder 14, 15. The elements 6, 8, and 9 of the feeder 3, which advance the sheet 27; the cylinders 10, 11, 12, 13, 14, 15, 20, 21, and 22 in and between the printing units l, 2; the driven rollers of the inking and wetting units 16-19; and the elements 27 of the delivery 4, which advance the sheet 23, are connected to each other by way of a common gear train and are driven by a main drive motor 28. The printing-form cylinders 14, 15 can also be driven with secondary drive motors 29, 30.
Rotary position transducers 31, 32 are provided at the transfer cylinders 12, 13 for detecting the angle of rotation.
A control device 33 is connected to the rotary position transducers 31, 32 for the signal input and to the main drive motor 28, the secondary drive motors 29, 30 and the imaging heads 25, 26 for the signal output. The control device 33 also receives signals from an image data storage unit.
Figure 2 shows the details of the drive of the printing press more closely. Figure 2 shows the printing-form cylinder 14 and the transfer cylinder 12, which are held in a sidewall 39 of the press with their pins 35, 36 in bearings 37, 38. Gears 40, 41 are secured on the pins 35, 36. The gears 40, 41, together with other gears 42, belong to a closed gear train, which is coupled to the main drive motor 28. For the separate driving of the printing-form cylinder 14, a secondary drive motor 29 is provided, whose motor shaft 43 is connected to the gear 40.
The secondary drive motor 29 is secured in a holding device 44. To detect the angle of rotation of the transfer cylinder 12, a rotary position transducer 45 is secured in the holding device 44, with the transducer shaft 46 thereof being connected to the gear 41. A control line 47 leads from the control device 33 to the secondary drive motor 29. The rotary position transducer 45 is connected to the control device 33 via a signal line 48. The drive is constructed equivalently in the printing unit 2.
Figures 3 and 4 illustrate the functioning of the drive system. In the print operation, the drive system operates in a first mode. The drive train is operated such that the tooth flanks of the gears 40, 41, i.e. those of the corresponding gears of the transfer cylinders 13 [sic] and the printing-form cylinder 15 in the printing unit 2 as represented in Figure 3, touch each other. The tooth flank contact is continuously maintained during the print operation in order to prevent doubling phenomena. Expediently, the secondary drive motor 29 can also be operated so as to exert a slight braking influence, so that the tooth flank contact is also maintained given sharp load fluctuations.
In the imaging operation, the drive system 14 operates in a second mode. As represented in Figure 4, the printing-form cylinders 14 and 15 are driven by the secondary drive motor 29 and 30, respectively, in such a way that the tooth flank contact of the gears 40, 41, i.e. of the corresponding gears of the transfer cylinder 13 and the impression cylinder 15 in the printing unit 2, is eliminated or is so slight that no mechanical disturbances are transferred to the printing-form cylindersl4 and 15 via the drive train. It is also possible for part of the gears belonging to the respective inking units 18, 19, or wetting units 16, 17, respectively, to be driven via the secondary drive motors 29, 30. In order to eliminate the tooth flank contact or reduce it to a harmless scale, the actual values of the angle of rotation and the torsional vibrations that are present at the respective transfer cylinder 12, 13 are continuously fed to the control device 33 via the signal line 48. These signals are processed in the control device 33 into actuating signals for the main drive motor 29 and the secondary drive motors 29 and 30. The control of the angle synchronicity of the gears 41, 42 of the main drive train relative to the gears 40 of the secondary drive train is dynamic enough to reliably prevent tooth flank contact between the gears 40, 41.
In a variant of the invention, it would be possible to additionally process signals from additional rotary positional transducers, which are coupled with the rotation of the printing-form cylinders 14, 15, in the control device 33.
Claims (3)
1. Method for driving a printing press, wherein at least one drum, which advances the printing material, and one printing-form cylinder are driven via a gear train by at least one first motor in the print operation, whereby angle-of-rotation signals of the drum are processed in a control device to control the drive, and wherein the printing-form cylinder is driven by a separate motor during the production of a printing form in the printing press, characterized in that in the production of the printing form, the two motors (28, 29, 30) are actuated synchronously, whereby a gear (40), which is allocated to the drive of the printing-form cylinder (14, 15), and an adjacent gear (41), which is allocated to the drive of the drum (12, 13), of the gear train (40-42) do not touch, or these exert slight pressure on one another.
2. Method as claimed in claim 1, characterized in that during the production of the printing form, signals indicating the angle of rotation of the printing-form cylinder (14, 15) are also processed in the control device (33).
3. Printing press, containing a gear train for driving a printing-form cylinder and at least one drum that advances printing material;
also containing at least one first motor for driving the printing press during the print operation and one additional motor for driving the printing-form cylinder during the production of a printing form in the printing press;
and containing a rotary position transducer for detecting the angle position of the printing-form cylinder and the drum during the print operation;
and containing a motor control device, which is connected to the rotary position transducer, characterized in that an additional rotary position transducer, which is connected to the motor control device (33), is provided for detecting the angle position of the printing-form cylinder (14, 15) in the production of the printing form.
also containing at least one first motor for driving the printing press during the print operation and one additional motor for driving the printing-form cylinder during the production of a printing form in the printing press;
and containing a rotary position transducer for detecting the angle position of the printing-form cylinder and the drum during the print operation;
and containing a motor control device, which is connected to the rotary position transducer, characterized in that an additional rotary position transducer, which is connected to the motor control device (33), is provided for detecting the angle position of the printing-form cylinder (14, 15) in the production of the printing form.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10114095 | 2001-03-22 | ||
DE10114095.9 | 2001-03-22 |
Publications (1)
Publication Number | Publication Date |
---|---|
CA2375431A1 true CA2375431A1 (en) | 2002-09-22 |
Family
ID=7678599
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA 2375431 Abandoned CA2375431A1 (en) | 2001-03-22 | 2002-03-08 | Method for a driving a printing press |
Country Status (2)
Country | Link |
---|---|
JP (1) | JP4242104B2 (en) |
CA (1) | CA2375431A1 (en) |
-
2002
- 2002-03-08 CA CA 2375431 patent/CA2375431A1/en not_active Abandoned
- 2002-03-19 JP JP2002076321A patent/JP4242104B2/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
JP2002292829A (en) | 2002-10-09 |
JP4242104B2 (en) | 2009-03-18 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
FZDE | Dead |