JP3331241B2 - Drive for a printing machine with multiple printing units - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device for a printing machine having a large number of printing units, wherein the printing units are mechanically connected to each other through a gear train. One drive motor is provided, and the drive motor supplies power to the gear train at a predetermined torque ratio.

[0002]

2. Description of the Related Art The demands in the area of printing technology are directed both toward rationalization and towards quality improvement.
In order to achieve a high-quality multicolor printing, both sides being printed and possibly further varnished during the running of the machine, a large number of printing units are connected in series, especially in sheet-fed printing. Need to be placed. These printing units must be highly synchronized with each other with regard to their working mode.

[0003] In order to reduce the load on the gear train, it is common to use multiple drives in printing machines with a large number of printing units. That is, a number of drive motors are provided to power the gear train at various locations.

What is important here is that there is a constant power flow in the gear train during the entire printing process. A constant power flow causes a constant distortion in the gear train, which can ensure that the register is kept correct. If the power flow changes in the gear train due to different loads, uncontrollable distortion occurs in the gear train that can be regarded as an elastic body. When low frequency vibrations occur, a negative effect in the form of a double copy error or registration error will be noticed on the printed product. Printed matter usually becomes waste paper due to these print defects.

In order to suppress a change in the direction of the power flow in the gear train of the printing machine, the drive motor is usually supplied with power to the gear train at a predetermined torque ratio. Although this measure ensures a constant tooth contact with the gear train, it is not in a state in which the strain that changes by itself as the load and speed changes can be suppressed in the gear train.
Registration errors caused by changes in power flow due to this non-constant distortion are usually caused by a mechanical sheet longitudinal register adjuster, either manually or automatically by an operator with the help of a register cross. Can be corrected via

[0006]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drive device which can automatically minimize misregistration between printing units.

[0007]

According to the present invention, there is provided a control device which is provided with information on a print characteristic value, and the control device changes the load torque in each printing unit from the print characteristic value. The above problem could be solved by determining Δm _i and controlling the drive motor so that the power flow in the gear train is constant at an average value over time.

[0008]

According to another configuration of the driving device of the present invention,
A storage device is provided in the control device, and the storage device stores a characteristic curve that describes a relationship between a change in load torque and each print characteristic value. This characteristic curve has been experimentally investigated in a test run.

In another embodiment of the drive device of the present invention, a computer device is provided in the control device, and the computer device generates a change in the print characteristic value in the print unit. The change in load torque is calculated. Advantageously, the control device compensates for the change in load torque occurring in the printing unit such that the corresponding stored or calculated change in drive torque is added to the corresponding drive motor. .

Regarding the printing characteristic value which affects the load torque, first, the printing speed, that is, the rotation speed of the printing press must be mentioned. Another influencing variable is, for example, the viscosity of the printing ink that can move from printing unit to printing unit, or the distribution of ink to individual printing units, the calculation of which, for example, determines the position of the ink zone screw. Is possible through. Another variable that must be mentioned in this position is the temperature of the inking unit and / or the dampening unit. In other words, the temperature of the inking unit has a considerable effect on the tackiness of the ink and, consequently, on the load torque of the corresponding inking unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the drawings of the embodiments.

FIG. 1 is a schematic view of a printing press 1 provided with a driving device according to the present invention. The printing press 1 has a large number of printing units 2, one paper feed device 3, and one paper discharge device 4. Each of the printing units 2 is provided with one drive motor 5. The drive motor 5 is controlled by a rotation speed controller 6. The rotation speed controller 6 gives a target current value _Isoll to each drive motor 5. That is, in this special example, the torque ratio of the drive motor 5 is 1: 1. A change in a predetermined characteristic value of the printing unit 2, for example a change in the number of revolutions n, a change in the temperature T of the inking and / or dampening device, a change in the ink distribution X or a change in the viscosity of the printing ink can be effected in individual printing units. The load torque change Δm _i is changed to 2. Here, i represents a special printing unit. The driving device according to the present invention is designed so that it can be automatically corrected by a change in the load torque according to the printing characteristic value. That is, each drive motor 5 can provide the corresponding printing unit 2 with power that is just adapted to meet its power requirements and thus to have a constant power flow in the gear train.

[0013] A constant distortion in the gear train guarantees a correct registration of the printed product, so that the printed product can be adjusted very precisely with the drive according to the invention.
Changes in the required load torque of the individual printing units or changes in output demands are detected via a control device 7 arranged in a storage device 8.

The control device 7 receives via a data line 9 information on the instantaneous state, for example, information on the rotational speed of the printing press 1, the temperature of the inking and / or dampening device, the viscosity of the printing ink and the like. ing. The storage device 8 and the characteristic curve is stored, the the characteristic curve, the load torque changes m _i of the printing unit 2 is relevant is given that changes depending on the characteristic values of the individual printing units .
Since the change in load torque {m _i is defined so as to compensate for the stitch of registration between the individual printing units 2 which appears with the change in load torque, the detected change in load torque { m automatic addition of _i is performed, it by a drive motor 5, the corresponding printing unit 2 is guaranteed to be able to satisfy the output request of the respective to instantaneously required.

[Brief description of the drawings]

FIG. 1 is a schematic view of a printing press provided with a drive device of the present invention.

FIG. 2 is a diagram of a circuit arrangement for compensating for changes in load torque in individual printing units.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printing machine 2 Printing unit 3 Paper feeder 4 Paper discharger 5 Drive motor 6 Rotation speed controller 7 Control device 8 Storage device 9 Lead wire

Continuation of the front page (72) Inventor Detlef Strunk Heidelberg, Germany Federal Republic of Brueckenstrasse 45 Examiner Katsumi Enari (56) References JP-A-62-171479 (JP, A) (58) Cl. ⁷ , DB name) B41F 33/00 B41F 13/00

Claims (8)

(57) [Claims] 1. A drive for a printing machine having a plurality of printing units, the printing units being mechanically connected to one another via a gear train, each printing unit being provided with one drive motor. The driving motor supplies power to the gear train at a predetermined torque ratio, and further includes a control device (7) for providing information on printing characteristic values. (7) determines the change Δm _i of the load torque in each printing unit (2) from the printing characteristic values, and sets the drive motor () so that the power flow in the gear train is constant at an average value over time. 5. A driving device for a printing machine having a large number of printing units, wherein the driving device controls 5). 2. A storage device (8) arranged and provided in the control device (7), wherein the storage device (8) indicates the relationship between individual print characteristic values and changes in load torque. The drive device according to claim 1, wherein a characteristic curve is stored. Wherein provided is arranged in the computer unit (8) control unit (7), the computer device (8), a change in m _i of the load torque generated in the printing unit (2) in 2. The driving device according to claim 1, wherein the driving device calculates the value based on the print characteristic value. 4. The control device (7) includes a printing unit (2).
The change Δm _i is compensated by adding a change amount of the drive torque corresponding to the change Δm _i of the load torque occurring to the corresponding drive motor (5). Item 2. The driving device according to Item 1. 5. The printing characteristic value is a rotation speed n of the printing machine (1).
The driving device according to claim 1, wherein: 6. The driving device according to claim 1, wherein the printing characteristic value is a viscosity (V) of the printing ink in each printing unit. 7. The driving device according to claim 1, wherein the printing characteristic value is an ink distribution amount (X) in each printing unit. 8. The drive according to claim 1, wherein the printing characteristic values are inking unit temperatures and / or dampening unit temperatures (T) in the individual printing units.