Method for compensating for an oscillation in a printing press

Abstract

In a method for compensating an oscillation which has a frequency spectrum with a number of discrete frequency components in a printing press, at least one counter torque is introduced into the printing press in order to compensate for at least one discrete frequency component of the oscillation. A first group of one or more frequency components are compensated for by introducing one or more previously determined counter torques, and a second group of one or more frequency components is compensated for by introducing specific counter torques as a function of a measurement, carried out during the operation of the printing press, of at least one signal which contains at least the one or the plurality of frequency components.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing a qualitative illustration of an exemplary representative frequency spectrum of an oscillation of a sheet-fed printing press according to the invention; and

FIG. 2 is a diagrammatic, illustration of an embodiment of a printing press according to the invention.

Claims

1. A method for compensating for an oscillation having a frequency spectrum with a number of discrete frequency components in a printing press, which comprises the steps of: introducing at least one previously determined counter torque into the printing press for compensating for a first group of components containing at least one of the discrete frequency components; andintroducing further specific counter torques as a function of a measurement, carried out during an operation of the printing press, of at least one signal containing at least one of the discrete frequency components for compensating a second group of components containing the at least one discrete frequency component.

2. The method for compensating for the oscillation according to claim 1, wherein the second group contains at least one discrete frequency component which is not contained in the first group.

3. The method for compensating for the oscillation according to claim 1, wherein the discrete frequency components of the first group and of the second group together yield a substantial part of the frequency spectrum or exactly the frequency spectrum.

4. The method for compensating for the oscillation according to claim 1, wherein: the at least one discrete frequency component of the first group is an integer multiple of a machine frequency ωM; andthe at least one discrete frequency component of the second group is a non-integer multiple of the machine frequency ωM.

5. The method for compensating for the oscillation according to claim 1, wherein: the at least one discrete frequency component of the first group is a load-relevant frequency; andthe at least one discrete frequency component of the second group is a register-relevant frequency.

6. The method for compensating for the oscillation according claim 1, which further comprises carrying out the introducing of at least one of the previously determined counter torque and the further specific counter torques at locations selected in accordance with an amplitude variation of one of eigenforms of the printing press.

7. The method for compensating for the oscillation according to claim 1, wherein the measurement of the at least one signal includes at least one orthogonal correlation for determining amplitude and phase of a frequency component of the second group.

8. The method for compensating for the oscillation according to claim 1, which further comprises producing and introducing the at least one previously determined counter torque by means of one of at least one mechanical device and at least one electric cam.

9. The method for compensating for the oscillation according to claim 1, which further comprises introducing the further specific counter torques only if a frequency component corresponding to the further specific counter torques is in resonance with an eigenfrequency of the printing press.

10. The method for compensating for the oscillation according to claim 1, which further comprises: introducing the at least one previously determined counter torque substantially at at least one of a start and at an end of a series of printing units of the printing press; andintroducing the further specific counter torques in a vicinity of a middle of the series of the printing units of the printing press.

11. The method for compensating for the oscillation according to claim 1, which further comprises determining the at least one discrete frequency component of the second group by determining from a difference between signals from at least two encoders which are disposed at mutually different locations of the printing press.

12. The method for compensating for the oscillation according to claim 1, which further comprises introducing together the at least one previously determined counter torque and at least one of the further specific counter torques by one actuator.

13. The method for compensating for the oscillation according to claim 1, wherein the second group contains the discrete frequency components which are not contained in the first group.

14. A printing press, comprising: a device for compensating for an oscillation having a frequency spectrum with a number of discrete frequency components; andat least one actuator for introducing at least one counter torque into the printing press to compensate for at least one of the discrete frequency components of the oscillation, said at least one actuator couple to said device;said device causing an introduction of: at least one previously determined counter torque into the printing press for compensating for a first group of components containing at least one of the discrete frequency components; andfurther specific counter torques as a function of a measurement, carried out during an operation of the printing press, of at least one signal containing at least one of the discrete frequency components for compensating for a second group of components containing at least one of the discrete frequency components.