DE4214707A1 - Control of sheet-fed rotary printing machine - has machine control connected to printing machine and rpm duplication unit connected to machine control and current converter regulating unit - Google Patents

Abstract

The converter regulating unit (8) is arranged after the machine control (6) and the rpm duplication unit (12). A current value storage (13) storing the last respective separate printing current value is connected to the rpm duplication unit and is arranged between the machine control and the converter regulating unit. A control unit (9) is arranged between the regulating unit and a power part (10) for the printing machine drive motor (5). A starting torque control unit (15) contg. a computer unit (14) is provided, for computing a starting torque (MS) and a separate printing torque (MP), lying under the motor rated torque (MN). The separate printing torque is determined from the stored separate printing current value. ADVANTAGE - Influences starting torque with re-run up to separate printing rpm for printing machine drive motor. Printing quality is maintained and paper wastage reduced.

Description

The invention relates to a control for a printing press Drive motor of a sheet-fed rotary printing machine.

Printing presses consist of several printing units, their Cylinders are interconnected by a gear train. The printing press is driven by a DC drive interact with a machine control Speed control device (DE 35 41 276). Speed control devices are generally known (VEM- Paperback automation and electrical power plants, Verlag Technik Berlin, 3rd edition, S 852). These speed control devices consist essentially of a converter control device and a driver, including Power unit, current value transmitter and speed transmitter.

Speed repeaters are also known (DD 13 934), those before a machine stop, for example at a so-called stopper (machine stop in the event of irregularities in production printing operation) last production printing speed reached - Speed at the one based on the order optimal printing operation is possible - save and after a speed repeat command from the machine control approach this production speed again.

If the production speed remains constant, they have conditionally due to the mechanical-elastic behavior of the printing press adjusting and twisting the cylinder  of the printing units against one another leading deformations Influence on the printing result.

The disadvantage, however, is that when the production speed is restarted after machine stop, for example after stoppers, these mechanical-elastic deformations and the thereby resulting rotation of the cylinders to each other as a result the different during the restart process Acceleration moments unfavorable on the register of the print result impact and so-called start-up waste occurs.

The object of the invention is to provide starting torque control to influence the starting torque when restarting the production speed for a drive motor a printing press.

The object of the invention is characterized by the characteristics of Claim resolved.

The invention is illustrated below using an exemplary embodiment described in more detail.

The drawing shows the starting torque control according to the invention.

A printing press consists of a feeder 1 , a plurality of printing units 2 and a delivery arm 3 .

The cylinders of the printing press are connected to one another by a gear train 4 . The printing machine drive motor 5 is assigned to a gear wheel of the gear train. A machine control 6 is assigned to the printing press. The machine controller 6 contains, among other elements that are not important for understanding the invention, a speed repeater element 16 . The printing press drive motor 5 is arranged downstream of the machine control 6 via a converter control device 8 and a downstream control device 9 including the power section 10 . A current value transmitter 11 , which is connected to the converter control device 8 , is arranged in the power supply to the power unit 10 . A speed sensor 7 , which is also connected to the converter control device 8 , is mechanically coupled to the printing press drive motor.

A starting torque control 15 is arranged between the machine control 6 and the converter control device 8 . The starting torque control 15 is connected on the input side to the current value transmitter 11 and the speed transmitter 7 . The starting torque control 15 contains a speed repeater 12 with a downstream current value memory 13 and a computing unit 14 downstream thereof.

The operation of the device according to the invention will described below.

The printing press runs in production printing operation at a production printing speed selected in accordance with the print job and thus with a production printing torque M _F output by the printing press drive motor, which is directly proportional to the production printing current I _F. This continuous pressure flow is detected by the current value transmitter 11 .

In this operating state, the mechanical elastic behavior of the press due to twists the cylinder of the printing units constant against each other; it on the print result.

In the event of irregularities in the continuous printing operation, for example when double sheets occur, the printing press is run at a low speed. The production pressure speed and the production pressure flow are stored in the starting torque control 15 .

After the cause of the stop has been eliminated, the starting torque control 15 is activated by actuating the control element speed repetition 16 . This means that the process of starting up the printing press to the stored production printing speed is triggered by the speed repeater 12 : that is, the production printing current I _{F is} input into the computing unit 14 from the current value memory 13 . The starting current I _A to be provided for the starting process and the starting torque M _{A are} calculated in the computing unit 14 . The starting current / starting torque is below the nominal current / nominal torque and slightly above the production pressure current / production pressure torque. Preferably the starting torque is according to the relationship

M _A = M _F + M _F × ε

with 5. . . 10% is calculated. It is also possible to set the starting torque according to the relationship

M _A = M _F + ε

A constant value of approximately ε≈0.05 × M _Fmax is to be determined here, where M _{Fmax is} the drive torque at maximum printing speed.

The calculated starting current value (current and torque are directly proportional) is supplied to the printing press drive motor via the converter control device 8 , the control device 9 and the power unit 10 and the start-up process is thus initiated. After the production speed has been reached, the starting process is ended via the speed repeater 12 and the machine control 6 switches over to normal operation.

Due to the fact that the start-up process after stoppers not with the nominal torque of the press drive motor, but is carried out with virtually the production moment, are those caused by the mechanical-elastic behavior Deformations roughly equal to the deformations in production printing. This ensures that the registration of the Printed products in start-up mode not from the registration deviates in production printing, d. that is, none Start-up waste occurs.

List of reference symbols

1 feeder
2 printing unit
3 outriggers
4 gear train
5 press drive motor
6 machine control
7 speed sensor
8 converter control device
9 control device
10 power section
11 current sensors
12 speed repeater 13 current value memory
14 arithmetic unit
15 Starting torque control
16 Speed repeat element
M _A starting torque
M _F output pressure moment
M _{Fmax production pressure torque} at maximum printing speed
M _N nominal motor torque
I _A starting current
I _F continuous pressure flow

Claims (3)

1.Control for a printing press drive motor with a machine control connected to the printing press, a speed repeater arranged downstream of the machine control, a converter regulating device downstream of the machine control and the speed repeating arrangement, a control device downstream of the converter regulating device, including a downstream power section upstream of the printing press drive motor, and also with a the power converter connected to the converter control device and a speed transmitter connected to the speed repeater and the converter control device, characterized in that between the machine control ( 6 ) and the converter control device ( 8 ) a speed repeater device ( 12 ) and a speed repeater device connected to the current value transmitter ( 11 ) 12 ) subordinate current value memory (which stores the last production pressure current value in each case) ( 13) and a determined to be above the pressure from the stored current value Fort continuous printing torque M _F and the engine rated torque M _N M _A starting torque calculating arithmetic unit (14) containing Anfahrmomentsteuerung (15) is arranged. 2. Control for a printing press drive motor according to claim 1, characterized in that the starting torque M _A 5th . .10% above the production torque M _F. 3. Control for a printing press drive motor according to claim 1, characterized in that the starting torque M _A is greater than the production torque M _{F by} the constant value ε and the constant value ε is approximately 0.05 times the production torque at maximum printing power.