EP1110730B1 - Method for the diagnosis of a rotary printing press - Google Patents

Description

The invention relates to a method for diagnosing a Rotary printing machine according to the preamble of Claim 1.

Through the magazine "Papier und Druck" 32 (1983) 7, general part, pages 100 to 104, are the basics various diagnostic methods for printing presses known.

However, there is no indication of the use of Angular positions of rotating components for To take diagnostic procedures.

A disadvantage of the diagnostic methods shown is that angular deviations are not sufficient Accuracy can be recorded.

DE 41 37 979 A1 describes a drive for a Press. This drive points to every printing unit an angle encoder. The deviations of the signals of the Angle sensors are used to control the printing units a manipulated variable used to each other, with the Determining the manipulated variable is knowledge of an earlier one Measured value acquisition is used.

DE 41 36 785 A1 discloses a diagnostic device for a clock generation device on printing presses. It is A rotary encoder is arranged on a single-speed shaft.

The journal "Der Polygraph" 10-74, pages 729, 730, 732, 734 describes torsional vibration sensors on two cylinders to arrange. Their signals are related to a Relationship between duplication and torsional vibrations evaluated.

DE 195 05 692 A1 shows a video system with which Camera error, for example a cutter bar or Groove bar of a folder picked up and by means of Remote diagnosis can be evaluated.

The invention has for its object a method for To provide diagnosis of a rotary printing press.

This object is achieved by the features of Claim 1 solved.

The advantages that can be achieved with the invention exist especially in that a state of a Rotary printing machine is monitored. Maintenance times can move periodically due to wear, z. B. rotating components are predicted and then existing downtimes of the rotary printing press Maintenance. Loss of production as a result This minimizes wear.

In rotary rotary printing presses, the printing units of which each have their own position-controlled drive motor, the rotary pulse generators which are already available for controlling the drive motor are used. The output signals of the existing rotary pulse generators are evaluated, as a result of which the additional outlay for the diagnostic system according to the invention is low.
The wear condition of the entire printing unit, ie also components that are not provided with a rotary encoder, can be deduced by means of only one rotary pulse generator per printing unit, since neighboring components also influence a torsional vibration behavior of the component provided with the rotary pulse generator.
By processing the output signal of the rotary pulse generator in frequency spectra and assigning typical frequencies to certain components, it is possible to deduce the component that is subject to wear or damage.

The diagnostic system according to the invention is in the drawing shown and is described in more detail below.

Fig. 1

eine schematische Darstellung einer Druckeinheit einer Rollenrotationsdruckmaschine mit angeschlossenem Diagnosesystem;

Fig. 2

eine schematische Darstellung des Diagnosesystemes.

Show it

Fig. 1

is a schematic representation of a printing unit of a web-fed rotary printing press with a connected diagnostic system;

Fig. 2

a schematic representation of the diagnostic system.

A web 1 is by means of printing units 2, in example shown four printing units 2, in Schönund Reverse printing in a web-fed rotary printing press printed. Each of these printing units 2 is in Bridge construction symmetrical to lane 1. In Side frames 3 of these printing units 2 are each two blanket cylinders 4, two plate cylinders 6 and the associated inking or dampening units 7, 8 stored. The Inking units 7 are in the present example as Anilox short inking units, each consisting of one Ink transfer roller 9, an anilox roller 11 and one Doctor device 12, executed. The dampening units 8 are for example, designed as spray dampers and consist essentially of three Dampening solution transfer rollers 13, 14, 16 and one with these cooperating spray device 17th

The rubber and plate cylinders 4, 6 of a printing unit 2 are connected to one another, for example, via gear transmissions, not shown. Each printing unit 2 is driven by its own drive motor. This drive motor is e.g. B. flanged directly to the respective rubber cylinder 4 or drives it, for example, by means of an intermediate pinion. This rubber cylinder 4 is equipped with a position encoder designed as an angular position encoder, e.g. B. a rotary encoder 18, 19, 21, 22 (z. B. incremental encoder or resolver) provided.
In addition to the individual drive motors of a printing unit 2, the printing units 2 can be connected synchronously by means of a standing shaft. It is also possible to provide each rubber and plate cylinder 4, 6 with its own motor. Likewise, each rubber and plate cylinder 4, 6 with its own angular position encoder, for. B. a rotary encoder 18, 19, 21, 22 may be equipped.

In the exemplary embodiment, an evaluation device 23 essentially consists of four measuring cards 24, 26, 27, 28 assigned to the rotary pulse generators 18, 19, 21, 22, a time base 31, a control unit 32, a data memory 33 and a digital I / A assigned to a computer 34. 0 card 36. The four measuring cards 24, 26, 27, 28, each connected to a rotary pulse generator 18, 19, 21, 22, are synchronized by the time base 31. On the measuring cards 24, 26, 27, 28 there is an adjustment, for. B. for setting a number of increments of the respective rotary encoder 18, 19, 21, 22, for the rotary encoder 18, 19, 21, 22 and a data flow control between the measuring cards 24, 26, 27, 28 and the data memory 33. The measuring cards 24 , 26, 27, 28 are in contact with the control unit 32. In addition, this control unit 32 is linked to the time base 31, the data memory 33 and the digital I / 0 card 36. A reference psychronization for a starting pulse is located on the control unit 32 in order to start all measuring cards 24, 26, 27, 28 at the same time. In addition, the control unit 32 controls a measurement period, a number of revolutions, the time base 31 and outputs data to the I / O card 36. The data memory 33 is also connected to each measuring card 24, 26, 27, 28. The digital I / O card 36 establishes the connection between this evaluation device 23 and the computer 34. Settings of the control unit 32 and data transfer are carried out via this I / O card 36.
The rotary pulse generators 18, 19, 21, 22 each generate three signals, for example by means of a graduated disk provided with optical markings, which is scanned by opto-electrical converters. The first signal provides a reference pulse, the other two signals offset by 90 ° to each other z. B. 4096, meandering pulses per revolution. The reference pulse and the two signals are fed to the evaluation device 23, which records all signals synchronously in time. A reference signal is also fed to the evaluation device 23. This reference signal consists of a temporally constant pulse sequence, the constant frequency of which is substantially higher than a frequency of the signals of the rotary pulse generators 18, 19, 21, 22. This high-frequency reference signal is generated by means of an oscillator, e.g. B. a quartz crystal.
Signatures can optionally be compared with one another in the downstream computer 34. For example, the signals from rotary pulse generators 18, 19, 21, 22 of two rubber cylinders 4 can be compared with one another during one or more cylinder revolutions. This comparison signal generated in this way of two rubber cylinders 4 is a measure of the relative rotation angle deviation (relative movement) of these rubber cylinders 4 to one another and thus corresponds to a deviation of the register of the web 1. If the signals of the rotary pulse generators 18, 19, 21, 22 with the reference signal of the oscillator in Relative, these comparison signals thus determined represent a measure of the absolute rotation angle deviation or for the absolute deviation of the circumferential speed of the rubber cylinder 4. This comparison signal shows the course of the deviation of the rubber cylinder from a uniform rotary movement due to torsional vibrations, ie the course of the exact one (Preferably with an accuracy of 0.001 ° to 0.01 °) Angular position of the rubber cylinder 4. These torsional vibrations can, for example, benac from transmitted vibrations of the rubber cylinder 4, errors in the gear transmission, vibrations of the bearing of the rubber cylinder 4, before transmitted vibrations cylinder or induced by fluctuations in load. Each cylinder 4, 6 of a printing unit 2 has a typical course of the deviation from a uniform rotary movement. Within a printing unit 2, for example, these uniformity deviations of the cylinders 4, 6 can be combined to form groups which, although they are similar to a certain pattern, do not have to be absolutely identical. This comparison signal of the uniformity of the cylinders 4, 6 is fed to the computer 34 and compared there with stored, machine-specific, fixed reference signals for certain production conditions (e.g. speed, number of printing units, web material). These machine-typical reference signals (sample signals) were, for example, previously stored for various production conditions on a perfectly functioning rotary printing press in a wear-free and damage-free state or were determined on the basis of theoretical considerations and thus determined. To carry out the comparison, both the comparison signal of the uniformity of the cylinders 4, 6 and the pattern signals can be processed. This can be done, for example, using a fast Fourier analysis (FFT). The signals are broken down into frequency spectra with the associated amplitudes. It has proven to be advantageous not to relate these frequency spectra to time, but rather to a cylinder revolution, since most movements in a rotary printing press take place periodically to one cylinder revolution. The magnitudes of the amplitudes of the torsional vibration related to the cylinder revolution are then determined and compared. It is possible to break down each signal into its frequency spectra by means of an FFT or just to divide the deviation from the pattern signal into its frequency spectrum and then to evaluate it. The comparison of the measurement signals with the sample signals can be carried out continuously or at certain time intervals.

If one or more amplitudes of the frequency spectrum of the measurement signals change, the cause can be deduced on the basis of their frequency.
Damage to components, e.g. B. gears or cylinder bearings can be identified, for example, using this frequency analysis. For example, wear on the teeth of a gearwheel can be seen in a frequency spectrum which corresponds to a multiple of the cylinder rotation corresponding to the number of teeth. It is also possible to detect progressive wear on cylinder bearings and thus to determine maintenance intervals.
The deviation of the actual angular position of a cylinder or the deviation of the relative angular position of two cylinders from one another from the associated machine-typical reference signal is used as a measure of wear or damage to components.
This state of wear of certain components is continuously monitored and communicated to an operator, for example on a screen of a control center. The operator must then, for example, upon reaching a first limit value previously set, for example by the machine manufacturer, acknowledge the message about the state of wear and release the machine manually. When a second limit value is reached, for example, the machine or at least the unit in question is stopped.

In the illustrated embodiment, the Regulation of the motors of the printing units 2 required Rotary encoder 18, 19, 21, 22 used to the Generate measurement signals. Also other people's cylinders Units such as reel changers, feeders or Folders 18, 19, 21, 22 assigned to the folder used for evaluation and hereby conclusions on the state of wear certain, periodically moving components of these units are pulled. So can, for example, a profile of a cutting force cylinders involved in a cutting operation, e.g. B. of a cutting cylinder can be determined in the folder and from that to the state of wear of, for example Cutting bars or cutting blades are closed.

In addition to those already required for the drive motors Angular pulse generators 18, 19, 21, 22 can also be more Rotary encoder on periodically moving, z. B. rotating components, e.g. B. on all cylinders 4, 6, be provided.

The measurement signals or the evaluation of the measurement signals can get saved. This stored data can be saved at Need for remote diagnosis, for example via a modem or can be accessed via ISDN procedures.

LIST OF REFERENCE NUMBERS

1

train

2

printing unit

3

side frame

4

rubber cylinder

5

-

6

plate cylinder

7

inking

8th

dampening

9

Ink transfer roller

10

-

11

anilox roller

12

doctor device

13

Dampening transfer roller

14

Dampening transfer roller

15

-

16

Dampening transfer roller

17

spraying

18

Drehimpulsgeber

19

Drehimpulsgeber

20

-

21

Drehimpulsgeber

22

Drehimpulsgeber

23

evaluation

24

measuring card

25

-

26

measuring card

27

measuring card

28

measuring card

29

-

30

-

31

time basis

32

control unit

33

data storage

34

computer

35

-

36

I / O card

Claims (4)

1. Method for the diagnosis of a rotary printing machine, in which a cylinder participating in a cutting operation and belonging to a folder is provided with an angular position transmitter (18; 19; 21; 22) and, by means of this angular position transmitter (18; 19; 21; 22), a signal is determined relating to a course of an accurate, actual rotational angle position of the cylinder and that signal is compared with a defined, machine-typical reference signal relating to a course of the rotational angle position of the cylinder, and in that the deviation between the courses of the actual rotational angle position and the reference signal is used as a measure of wear or damage on the cylinder participating in the cutting operation.
2. Method according to Claim 1, characterised in that the signal is evaluated as a measure of the course of a cutting force.
3. Method according to Claims 1 or 2, characterised in that the signal relating to the actual rotational angle position and the reference signal and/or the signal relating to the deviation between the reference signal and the actual rotational angle position are broken down, by means of mathematical methods, into frequency spectra with the associated amplitudes, in that selected frequencies are assigned to specific components, and in that the amplitudes of these selected frequencies are used as a measure of the wear or damage on these components.
4. Method according to Claim 3, characterised in that the frequency spectra are calculated on the basis of cylinder revolutions.

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