CN113002130A

CN113002130A - Method for controlling the cylinder ram pressure in a printing unit

Info

Publication number: CN113002130A
Application number: CN202011509719.XA
Authority: CN
Inventors: S·内布
Original assignee: Heidelberger Druckmaschinen AG
Current assignee: Heidelberger Druckmaschinen AG
Priority date: 2019-12-19
Filing date: 2020-12-18
Publication date: 2021-06-22
Anticipated expiration: 2040-12-18
Also published as: CN113002130B; DE102019220116B3

Abstract

The invention relates to a method for controlling the pressure of a cylinder head in a printing unit, wherein the pressure between a first cylinder head of a first cylinder and a second cylinder head of a second cylinder is determined by means of a strain sensor (4), and one of the two cylinder heads is adjusted relative to the other by means of a servo drive. The strain of the component (6) is measured by means of a strain sensor (4), in which the first cylinder and the second cylinder are supported, wherein in a first step a first measurement value is obtained by means of the strain sensor (4) in a "printing inactive" mode, and in a second step a second measurement value is obtained in a "printing active" mode, wherein the cylinders are in contact with each other in the "printing active" mode, and are not in contact with each other in the "printing inactive" mode.

Description

Method for controlling the cylinder ram pressure in a printing unit

Technical Field

The invention relates to a method for controlling the press load/press load (Schmitzringpressung) of a printing couple, wherein the press load/press load (Pressung) between a first press pad of a first cylinder and a second press pad of a second cylinder is determined by means of a strain sensor, and one of the two press pads is adjusted (vertellt) relative to the other by means of an actuator/servo drive (Stellantrib).

Background

A mechanism is described in document DE 3520344C 2, in which the measurement value indicator is a strain gauge strip arranged on the shaft.

DE 102007036133 a1 describes a method in which, at least in a configuration operation or a printing operation, the plate cylinder is tracked by means of a remotely controllable adjusting mechanism on a radially adjustable plate cylinder bearing of the position of the blanket cylinder in such a way that the ram pressure does not exceed a predeterminable tolerance range.

DE 102010006781 a1 describes a method in which the deformation of one bolster is detected by means of a strain gauge strip in the region of the line of contact with the other bolster. The strain measuring strip is placed on the side of the bolster in the vicinity of its working face in such a way that the material strain is detected in the radial direction of the bolster. The strain measuring strip is connected with an amplifier, and the output end of the amplifier is connected with a control mechanism.

Disclosure of Invention

The object of the invention is to provide a further method for controlling the ram pressure in a printing unit.

This object is achieved by a method for controlling the cylinder pillow pressure in a printing unit, wherein the pressure between a first cylinder pillow of a first cylinder and a second cylinder pillow of a second cylinder is determined by means of a strain sensor, and wherein one of the two cylinder pillows is adjusted relative to the other by means of a servo drive, characterized in that the strain of the component in which the first cylinder and the second cylinder are supported is measured by means of the strain sensor, wherein a first measured value is obtained in a "print off (Druck ab)" mode in a first step by means of the strain sensor, and a second measured value is obtained in a "print on (Druck)" mode in a second step, wherein the cylinder pillows are in contact with each other in the "print on" mode and are not in contact with each other in the "print off" mode.

The following modifications of the invention can be implemented individually or (as long as they are not technically mutually exclusive) in any desired combination with one another:

the first step may be performed each time a print job is changed between two print jobs.

The second step may be performed multiple times during each print job.

A first average value can be formed by means of the electronic computer on the basis of the first measured values and a second average value can be formed on the basis of the second measured values.

The strain component (Komponente) related to the mechanical load of the two roll-rests can be calculated by forming the difference between the first average value and the second average value.

The component may be a side wall of a frame of a printing unit, wherein the strain of the component is measured by means of a strain sensor.

The measurement signal of the strain sensor can be smoothed by means of an analog filter

The PT1 element (PT1-Glied) can be used as a filter.

Strain sensors may be applied on the drive side and the operating side of the printing press.

These strain sensors may be threaded or bonded to the member, respectively, and then provide a signal proportional to the strain. A strain change of a few micrometers per meter is sufficient to obtain a good signal quality.

The strain sensors can be mounted on the side walls between the bearing bores, both on the drive side and on the operating side, in the connecting line of the blanket cylinder to the axis of the plate cylinder.

The configuration of the side walls can be changed as required in order to improve the integration of the sensor. For example, the sidewall may be optimized to locally surround the sensor such that the local strain variation of the sidewall is adapted to the measurement range of the sensor.

For protection and for reasons of installation space, the sensor can be integrated in a pocket recess in the side wall, so that the sensor can be mounted on the drum side on the side wall, whereby the sensor can be protected against oil contamination, which oil can be used for lubrication of the transmission on the other side of the side wall.

The adaptation of the side walls can be achieved by: so that only local effects occur in the range of the strain sensor, thereby enabling the structure to achieve its overall stability/stiffness, and thus not affecting the print quality.

Drawings

Further developments which can be realized individually or in any desired combination with one another or with the above-described developments, insofar as they are not technically mutually exclusive, result from the following description of the exemplary embodiments and the associated drawings.

The figures show:

FIG. 1: a "print enable" mode of the printing unit;

FIG. 2: the printing machine set is in a printing stop mode;

FIG. 3: a side wall of the printing unit;

FIG. 4: a strain sensor on the sidewall;

fig. 5 to 9: different variants of the mechanism for adjusting the drum bearing; and

FIG. 10: and controlling the technical connection relation of the strain sensor.

Components or elements that correspond to one another or that are functionally identical are denoted by the same reference numerals in fig. 1 to 10, so that a repeated description is not necessary.

Detailed Description

Fig. 1 shows: the first roller 11 is equipped with a first bolster 1 and the second roller 12 is equipped with a second bolster 2. The first cylinder 11 is a plate cylinder and the second cylinder 12 is a blanket cylinder. The two

cylinders

11, 12 are part of the printing unit 3 for offset printing. Here, a "print-enabled" mode is shown, in which the second cylinder 12 is pressed (angeletlt) onto the first cylinder 11 and thus the second bolster 2 is in contact with the first bolster 1.

Fig. 2 shows a "print-disabled" mode, in which the second cylinder 12 is de-pressed (abgettellt) from the first cylinder 11, so that the second pad 2 is not in contact with the first pad 1.

Fig. 3 shows a strain sensor 4, which strain sensor 4 is fixed to a component 6. The member 6 is a side wall of a frame 8 of the printing unit 3. Fig. 3 is based on a view from the inside of the printing unit 3 towards the side wall. The two

rollers

11, 12 are not shown together in fig. 3. Here, the figures show holes (without reference numbers) machined in the member 6 for housing the bearing portions of the two

cylinders

11, 12 described above. An imaginary connection center 13 extends between the geometric rotational axes of the

rollers

11, 12 and thus of the roll rests 1, 2 through the mounting position of the strain sensor 4. The strain sensor 4 is arranged in a pocket 14, which pocket 14 is machined in the component 6.

Fig. 4 shows a sectional view corresponding to line II-II in fig. 3, wherein the strain sensor 4 and the pocket 14 are shown enlarged.

Fig. 5 shows the second roller 12 and thus the bearing 15 of the second bolster 2. The bearing portion 15 comprises an inner ring 16 and an outer ring 17, which may also be referred to as eccentric sleeves. The pressing movement a1 for pressing the second roller 12 onto the first roller 11 and thus also the second roller pillow 2 onto the first roller pillow 1 is transmitted to the bearing 15 via the transmission 18. The transmission 18 is a coupling transmission and comprises a link with two arms (Schwinge). A coupling lever is articulated on one arm of the connecting rod, and the coupling lever is articulated on the inner ring 16; a coupling lever is articulated on the other arm of the connecting rod, which coupling lever is articulated on the outer ring 17. Integrated in the gear mechanism 18 is a servo drive 5, which servo drive 5 generates a setting movement x 1. The setting movement x1 is transmitted to the bearing 15, which bearing 15 thus adjusts the second roller 12 and the second bolster 2 toward the first roller 11 and the first bolster 1 or adjusts the second roller 12 and the second bolster 2 away from the first roller 11 and the first bolster 1. By this adjustment, the pressure between the

roll pillows

1, 2 is adjusted. The actuator 5 is integrated in one of the two coupling levers, in particular the coupling lever which is hinged to the outer ring 17. By activating the servo drive 5, the length of the coupling rod in which the servo drive 5 is integrated is lengthened or shortened. The servo drive 5 may be, for example, an electric motor with a helical gear transmission.

Fig. 6 shows a modification of the gear mechanism 18, in which the coupling rod of variable length for adjusting the ram pressure has the following sections: this section is formed as a parallelogram 19 from rods which are connected to one another in an articulated manner. The parallelogram 19 can also be referred to as a shear grid (Scherengitter) or a crank lever system (kniehebelsys). The servo drive 5 effects an adjustment movement a2, which folds the parallelograms 19 together or apart from one another as a result of the adjustment movement a2 and thereby changes the length of the coupling rod.

Fig. 7 shows a variant in which, instead of a two-arm link, two single-arm links are provided. One coupling rod is hinged on one connecting rod, and the other coupling rod is hinged on the other connecting rod. To produce the setting movement a2, the servo drive 5 rotates one link relative to the other about the common axis of rotation of the two links.

Fig. 8 shows a variant in which the two-armed lever is connected to the coupling lever which is articulated on the outer ring 17 via a short coupling lever.

Fig. 9 shows a variant in which the servo drive 5 is integrated in that arm of the two-arm lever which is articulated on the coupling lever which is articulated on the outer ring 17. The actuator 5 can also be designed as an electric motor with a helical gear mechanism.

Fig. 1 to 9 show and accordingly describe an arrangement on only one machine side (for example on the drive side or the operating side). Naturally, it is also possible to provide the same arrangement on the other side of the machine, so that there are two strain sensors 4 as a whole.

Fig. 10 effectively shows such a variant for all variants shown in fig. 1 to 9, in which the coupling of the strain sensors 4 to the actuating drives 5 is shown in terms of control technology. The strain sensor 4 is coupled to the servo drive 5 via a filter 9 and via an electronic computer 7 in order to form a control loop. The filter 9 may be an analog filter (e.g. a PT1 element).

The above-described apparatus operates as follows: each measurement of the strain sensor 4 is stored as a reference value (when the respective printing unit stops printing) at each change of print job. If the machine speed is equal to the official printing speed, the measurement procedure is started. Waiting for a certain number of revolutions of the drum (Umdrehung). The number may be, for example, 5 to 20. Most of the ringing and saturation of the filter occurs during acceleration of the machine. As a next step, measurements are made for a certain number of revolutions of the cylinder and thus of the bearer rings 1, 2 by means of strain sensors 4 arranged on the drive side and on the operating side of the printing press. The number of revolutions during which the measurement is performed may be, for example, 5 to 20. An average value is formed in the computer 7 on the basis of the measured values obtained in the measurements, wherein this calculation result is the value of each pair of bolsters. The reference value is subtracted from the average value. The strain signal is then converted into a force signal, for example by means of a Look-up table (Look-up-table). During the printing job, only a part of the above-described method sequence is repeated. The part starts with a third step (waiting for a certain number of revolutions). Every time a print job is changed, all the above-described method flows starting with the first step (storing individual sensor values as reference values) are repeated.

The method according to the invention has different advantages: by using the method, waiting times and associated machine downtimes, which otherwise occur during manual setting of the ram pressure, are avoided. The method according to the invention detects possible changes in the ram pressure during the printing press operating time. Furthermore, the method according to the invention takes into account the influence of the temperature increase on the ram pressure due to the printing run.

List of reference numerals

1 first rolling pillow

2 second rolling pillow

3 printing unit

4 strain sensor

5 Servo driver

6 component

7 computer

8 machine frame

9 filter

11 first roller

12 second roller

13 connecting center

14 bag slot (Tasche)

15 support part

16 inner ring

17 outer ring

18 driving device

19 parallelogram

a1 closing pressure sport (Anstellbewegung)

a2 setting movement

x1 set motion.

Claims

1. A method for controlling the bearer pressure in a printing unit (3),

wherein the pressure between the first bolster (1) of the first roller (11) and the second bolster (2) of the second roller (12) is determined by means of a strain sensor (4), and

wherein one of the two roll rests (1, 2) is adjusted relative to the other by means of a servo drive (5),

it is characterized in that the preparation method is characterized in that,

measuring the strain of a component (6) in which the first roller (11) and the second roller (12) are supported by means of the strain sensor (4),

wherein a first measurement value is obtained in a first step in a print-off mode of the printing unit (3) by means of the strain sensor (4) and a second measurement value is obtained in a print-on mode in a second step,

wherein the pillows (1, 2) are in contact with each other in a 'print-on' mode and are not in contact with each other in a 'print-off' mode.

2. The method of claim 1, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the first step is performed between two print jobs each time a print job change is made.

3. The method according to claim 1 or 2,

it is characterized in that the preparation method is characterized in that,

the second step is performed a plurality of times during each print job.

4. The method according to one of claims 1 to 3,

it is characterized in that the preparation method is characterized in that,

a first mean value is formed on the basis of the first measured value and a second mean value is formed on the basis of the second measured value by means of an electronic computer (7).

5. The method of claim 4, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

the strain component related to the mechanical load of the two roll rests (1, 2) is calculated by forming the difference between the first average value and the second average value.

6. The method according to one of claims 1 to 5,

it is characterized in that the preparation method is characterized in that,

the component (6) is a side wall of a frame (8) of the printing unit (3).

7. The method according to one of claims 1 to 6,

it is characterized in that the preparation method is characterized in that,

the measurement signal of the strain sensor (4) is smoothed by means of an analog filter (9).

8. The method of claim 7, wherein the first and second light sources are selected from the group consisting of,

it is characterized in that the preparation method is characterized in that,

a PT1 element was used as the filter (9).