EP1900526B1 - Cloth feed control device of a cleaning device for printing press cylinders - Google Patents

Description

The invention relates to a cloth feed control device of a cleaning device for printing press cylinder according to the preamble of claim 1.

Furthermore, the invention relates to a cleaning device having such a cloth feed control device.

Also, the invention relates to a control system, which contains two or more cloth feed control means for corresponding two or more cleaning devices for printing press cylinders in a printing press, for. B. in an offset printing machine.

The cleaning devices are designed for the rotatable mounting of two cloth rolls, of which one roll of cloth is a cleaning cloth roll, and the other cloth roll is a dirty cloth roll. The dirt cloth roll is automatically driven by a drive step by step, z. B. from a pneumatic cylinder to transfer the cleaning cloth step by step to a predetermined Tuchvorschublänge of the cleaning cloth roll on the dirty cloth roll. The cleaning cloth is transported during a cleaning process at least once, preferably several times to each of the predetermined cloth feed length, so that in each case a clean cloth section to the cylinder circumference of the press cylinder to be cleaned is created. The cleaning cloth may be dry or damp. The cleaning cloth may already be damp on the cleaning cloth roll or moistened only on the way to the dirty cloth roller at a location which is in front of the point at which the cleaning cloth is pressed by means of a pressing element to the cylinder circumference.

State of the art

A cloth feed control device according to the preamble of claim 1 is known from EP 0 755 789 A1 known. Other cloth feed control devices of printing machine cylinder cleaning devices are off DE 100 44 861 A1 . DE 44 42 412 A1 and DE 10 2005 003 166 A1 known.

From the DE 10 2005 003 166 A1 For example, a washing apparatus for a printing press is known, which includes an ultrasonic sensor for detecting the level of cloth of a cleaning cloth roll. This is to determine when only a predetermined short amount of residual cloth on the cleaning cloth roll is present, which would not be sufficient for a new printing operation. This eliminates the need to stop printing because the cleaning cloth will not last until the end of the printing process.

One of several embodiments of a printing machine cylinder cleaning apparatus is known from US 5,156,237 DE 101 60 197 A1 known.

An automatic cylinder cleaning device for printing presses is also from the US 4,344,361 known.

Brief description of the invention

By the invention, the problem to be solved, a cleaning device and in particular their control device for the cleaning of printing press cylinders in such a way that a more efficient use of the cleaning cloth is possible.

This object is achieved according to the invention by the features of claim 1.

Further features of the invention are contained in the subclaims.

Furthermore, the object is achieved according to the invention by a cleaning device, which is provided with a cloth feed control device according to the invention.

The invention also relates to a control system which includes two or more cloth feed control means for correspondingly two or more press cylinder cleaners.

Accordingly, the invention also relates to an installation which contains two or more cleaning devices for cleaning printing press cylinders and a corresponding number of cloth feed control devices.

The invention includes several features that can be used individually and in combination to advantage:

A non-contact sensor, preferably an ultrasonic sensor, scans the circumferential surface of one of the two cloth rolls, preferably the cleaning cloth roll, and generates a signal corresponding to the radius of the cloth roll, in particular an electric current strength or alternatively a voltage level, depending on the detected distance. The sensor is preferably designed such that changes in distance result in linear changes in the signal value. With the radius thus determined, the cloth roll circumference is automatically calculated. The calculated cloth roll circumference is set in relation to a defined cloth feed length (cloth feed length set value) by means of a number of increments defined in the total circumference of the cloth roll. The defined cloth feed length is the cloth feed length by which the cloth is to be transported on each feed step of the cleaning cloth roll in the direction of the dirty cloth roll on. The value to be determined for the number of increments to be returned, which for the Feed of the defined cloth feed length are rounded in the case of decimal values, rounded up, for example, from a decimal value of 0.5 to the next integer, otherwise rounded to the nearest integer. If the active cloth feed has reached the determined value of the increments, the cloth feed is automatically ended, eg. B. by deactivating a valve through which a pneumatic drive compressed air can be supplied.

According to another aspect of the invention, the number of increments taken in a cloth advancement step is added and stored in a sum memory. The stored number of increments can be used for various purposes, for example, to automatically calculate the used cloth length or remaining on the cleaning cloth roll cloth length and / or to generate a signal when there is only a predetermined minimum residual length of cloth on the cleaning cloth role.

A particularly advantageous use of the summed values of traveled increments stored in the summation memory is to automatically calculate an average value from the summation values of two or more cleaning devices of a printing machine and to determine this average value as a setpoint for all cleaning devices within the same printing machine. For all cleaning devices, the difference between the stored increments stored in the total memory and the desired value is determined and this difference is also stored. In the case of deviations of the difference from a defined limit value on a cleaning device upwards or downwards, the number of increments to be returned is increased by at least the next cloth feeds of the same cleaning operation or the next cleaning operation from the number of increments to be determined dependent on the roll diameter Reduction is adjusted so that the total number of recirculated increments of the various purifiers aligns again or the total number of increments taken back becomes the same across all purifiers. In this case, it must be ensured that a reduction in the number of increments during a cloth feed does not fall below a defined minimum value of increments, to ensure that always enough fresh cleaning cloth is placed on the press cylinder to be cleaned.

The cleaning devices are commonly referred to as washing bars because they extend in a beam-like manner across the printing press for substantially the same length as the printing press cylinder to be cleaned.

Advantages of the Invention: The invention dispenses with previously required mechanical parts such. B. cloth end limit lever, cloth-touch spoon or ratchet wheel with a drive roller. In contrast to these parts, no malfunctions due to contamination can occur in the invention since all parts required according to the invention can be accommodated in a protected space. Furthermore, the known parts have the disadvantage that they can be bent or broken on the printing machine by external influence. These disadvantages are also avoided by the invention.

Fig. 1

schematisch eine Reinigungsanlage mit zwei (oder mehr) Reinigungsvorrichtungen und zugehörigen Tuchvorschub-Steuereinrichtungen nach der Erfindung, welche zusammen eine Steueranlage nach der Erfindung bilden,

Fig. 2

schematisch eine Darstellung, wie 360° um die Drehachse einer Tuchrolle in gleich große Inkremente aufteilbar sind.

The invention will now be described by way of example with reference to the drawings of preferred embodiments. In the drawings show

Fig. 1

2 schematically shows a cleaning system with two (or more) cleaning devices and associated cloth feed control devices according to the invention, which together form a control system according to the invention,

Fig. 2

schematically a representation of how 360 ° about the axis of rotation of a cloth roll in equal increments are divisible.

Fig. 1 schematically shows two cloth feed control devices 2-1 and 2-2 for an equal number of cleaning devices 4-1 and 4-2 for cleaning of correspondingly also two printing press cylinders 6-1 and 6-2 of a printing press, for. B. an offset printing machine. Since both cloth feed control devices 2-1 and 2-2 as well as the two cleaning devices 4-1 and 4-2 can each be designed the same, in the following only one Cloth feed control device 2-1 described for a cleaning device 4-1, as far as nothing else is mentioned below.

The cleaning device 4-1 extends substantially the entire length of the printing press cylinder 6-1 to be cleaned by it. It is designed for the rotatable mounting of two cloth rolls, one of which is a cleaning cloth roll 8 and the other is a dirty cloth roll 10. The dirty cloth roll 10 is gradually rotated by an automatic driving device 11 to transport a predetermined cloth feeding length from the cleaning cloth roll 8 to the dirty cloth roll 10, respectively. In this case, the roll diameter of the two cloth rolls 8 and 10 changes. On the transport path of the cleaning cloth 12 in the transport direction 14 is a pressing member 16 for pressing the cleaning cloth 12 to be cleaned to the printing press cylinder 6-1. Furthermore, a liquid spray device 18 for spraying the cleaning cloth 12 with liquid, for. As water and / or a cleaning agent may be provided. For a cleaning process, the cleaning cloth 12 is applied at least once or more times by means of the pressing member 16 and / or by moving the entire cleaning device 4-1 to the cylinder peripheral surface of the printing press cylinder 6-1 and then again distanced therefrom. After each application to the printing press cylinder (or according to another embodiment during the application), the cleaning cloth is transported in one step by the predetermined cloth feed length on.

The drive device 11 may be formed in various ways. It may for example contain an electric stepper motor or a pneumatic drive 20 (piston-cylinder unit), the piston of a valve 22 controlled axially reciprocable and drives via a drive connection 24 a freewheel 26, which with a cloth roll core 28 of Dirt roll 10 is drivingly connected.

The cloth feed control device 2-1 includes a non-contact distance sensor 30. The distance sensor 30 is for generating signals, preferably analog signals, in the form of an electric current value or an electric Voltage value formed depending on the respective radial distance of the distance sensor 30 from the outer periphery of one of the two cloth rolls, for example, the cleaning cloth roll 8 (or the dirty cloth roll 10). The signals of the distance sensor 30 change linearly in proportion to changes in the radial distance of the outer periphery of the cloth roll from the distance sensor 30. The distance sensor 30 is positioned at a predetermined distance 32 from the rotation axis 34 of the cleaning cloth roll 8 radially to the rotation axis 34, so that the analog signals of the distance sensor 30th correspond to the respective radius of the cloth roll, although the distance sensor 30 actually detects only its distance to the cloth roll peripheral surface. The distance sensor 30 is preferably an ultrasonic sensor whose sound transit time from the distance sensor 30 to the cloth roll peripheral surface and back again is a measure of the distance. Fig. 1 schematically shows the transmitted ultrasonic beam 36 and the reflected ultrasonic beam 38th

Furthermore, the cloth feed control device 2-1 contains a control part 40 which is connected to the distance sensor 30 and calculates the respective circumferential size of this cleaning cloth roll 8 from its analog signal, which corresponds to the radius of the detected clean cloth roll 8. In the control part 40, a cloth feed length set value 42 is stored or stored, which indicates how large the cloth feed length should be at a feed step. Further, in the control part 40, a predetermined number of increments for a 360 ° rotation of the cloth roll 8 are stored. In other words, the circumference of the roll of cloths 8 of 360 ° is divided into equally large rotation angle increments.

The control part 40 is designed to calculate how many increments the cloth roll 8 has to be rotated in order to transport the cleaning cloth at the calculated peripheral size of the cloth roll 8 by a cloth feed length corresponding to the desired value by means of the drive device 11. For this purpose, the control part 40 is designed to generate a setpoint value corresponding to the calculated increments for the drive device 11.

The control part 40 is preferably provided with at least one processor for performing the calculations and with a data memory.

Fig. 2 schematically shows an end view of one of the two cloth rolls, for example, the cleaning cloth roll 8. Your front page is divided about its axis of rotation 34 over 360 ° in the said predetermined number of increments of equal size. The larger the number of increments, the higher the accuracy of the cloth feed control. For example, 360 increments or 720 increments may be provided. For a clear representation of the principle are in Fig. 2 only 16 increments 0 to 16 shown. The cloth feed length, which is transported by an increment upon rotation of the cloth roll 8, is dependent on the outer cloth roll diameter or radius. From the measured radius, the control part 42 calculates the cloth roll circumference. By way of example, suppose that the cloth roll circumference U1 is equal to 10 mm between two increments. Further, it is assumed that with a smaller diameter U2, the cloth length portion between two increments is only 5 mm. It can be seen that for a desired cloth feed length (setpoint) of 10 mm, the cleaning cloth roll 8 at the large diameter U1 only needs to be rotated by one increment, while it has to be further rotated by 2 increments at the small diameter U2 to the same Unwind cloth feed length of the cloth roll 8. The same function can be achieved if the analog distance sensor 30 does not detect the cleaning cloth roll 8 but the dirty cloth roll 10.

When calculating in the control part 40 by how many increments the cleaning cloth roll 8 has to be rotated in order to transport the cleaning cloth 12 by a cloth feed length corresponding to the desired value by means of the drive device 11 at a calculated circumferential size, decimal amounts (comma amounts) may result. The control part 40 may be designed such that it always rounds up these decimal amounts or always rounds them off or is designed such that it rounds up to the next whole number from a predetermined decimal value of, for example, 0.5, otherwise rounds off to the next whole number.

There are several ways to detect how many increments the roll of cloth 8 or 10 at each cloth feed or from a certain start position for all Towel feeds in total was turned. If the dirty cloth roll 10 is driven by an electric stepper motor, it is possible to count the control pulses and thus the individual steps of the stepping motor as increments in an automatic counter and to store in a memory. Another way of counting and storing increments is to use an encoder 44. It can be arranged to count the increments (turns) of the dirty cloth roll 10 or the clean cloth roll 8. The count of the increments on the cleaning cloth spindle 8 is more accurate than on the dirt roller 10, because of the stretchability of the cleaning cloth 12 and because of play between the individual elements. As one of the possibilities shows Fig. 1 an encoder 44, which has an encoder disc 46 provided with increment markings 45 (lines, holes, etc.) and an encoder sensor 47 for detecting the increment markings 45. The encoder sensor 47 is connected to the control part 40 so as to supply an electrical signal every time an increment mark 45 is detected. The incremental slide 46 is connected to the dirty cloth roll 10 (or the cleaning cloth roll 8) via a connecting member 48 for common rotation. The connecting element is z. B. connected to a coupling element, which is connected to the winding core 28 of the Schmutzruchrolle 10 (or the cleaning cloth roll 8) or connectable. The increment markers 45 may be provided on another encoder instead of an encoder disk 46, which is connected to the cloth roll 10 or 8 directly or via a reduction or translation.

The control part 40 preferably includes a totalizer 50 for counting the total number of increments or increment marks 45 around which the dirty cloth roll 10 and thus also the clean cloth roll 8 has been rotated for all initial advances of cloth advance lengths performed since a first start. The total number of already rotated increments can be used for different purposes. It is a measure of how much cleaning cloth has already been wrapped by the cleaning cloth roll 8 on the dirty cloth roll 10 and also how much remaining cloth length is still present on the cleaning cloth roll. There is the advantageous possibility of automatically displaying the total number of increments or a length measure corresponding to this total number, either the towel roll already unwound from the cloth length or remaining on it remaining cloth length. It is also possible to generate an optical or acoustic signal when there is only a predetermined minimum remaining towel length on the cleaning cloth roll 8. The minimum remaining towel length can be important if it is still sufficient to carry out all cleaning operations during a printing process, or a new cleaning cloth roll 8 is required in order to perform a printing process without interruption.

The analog distance sensor 30 and / or the encoder 44 are preferably arranged on the cleaning device 4-1 or 4-2 and form together with this a structural unit which can be inserted into a printing press. The control part 40 can also be arranged on the cleaning device, but is preferably arranged separately from it.

A printing machine usually includes a plurality of cleaning devices 4-1, 4-2, etc. (washing bars) for cleaning a plurality of printing press cylinders 6-1, 6-2, etc. It is desirable to have cleaning cloths 12 in all cleaning devices 4-1, 4-2, etc at the same time so that the printing operation does not have to be interrupted several times. The invention offers the possibility of comparing the total number of increments counted and stored since a first start of cloth feeds with all cleaning devices 4-1 and 4-2 and making changes to the setpoint control signal for the drive device 11 such that different total numbers of increments be compensated again. According to a preferred embodiment of the invention, therefore, the control parts 40 of all cleaning devices 4-1 and 4-2 are designed to generate a difference signal from the actual value of the total number of counted increments of their sum counter 50 and from an increment total number setpoint. The increment total number target value is the average value of a plurality of cleaning devices 4-1 and 4-2 in a printing machine obtained by adding the total number of counted increments of the sum counters 50 from all the cleaning devices 4-1 and 4-2 and then dividing the total number Addition value by the number of cleaning devices 4-1 and 4-2 results. This calculation may preferably be performed automatically or by a person who reads the total number of counted increments of the totalizers 50 on a cumulative counter display or from a print-out, then adds the addition value by the number of cleaners, and then enters the thus calculated increment total number setpoint in the control parts 40. The control parts 40 of all the cleaning devices 4-1 and 4-2 are designed to generate a corrected control signal target value which, instead of the original target value for the predetermined cloth feed stroke, takes effect if the difference signal deviates from a predetermined permissible difference value. This difference value can be 0 or have a different value.

According to a preferred embodiment of the invention, a controller combination is provided which comprises two or more cloth feed control devices 2-1 and 2-2 for respectively two or more cleaning devices 4-1, 4-2, etc. in a printing machine, and which for automatic calculation and application of the increment total number setpoint is formed.

The controller combination includes a comparison part 60 which is connected to the control parts 40 of all the cleaning devices 4-1, 4-2, etc. and has a summation memory 62. The comparing part 60 includes a calculator 64 which adds the total number of increments of the sum counters 50 from all the control parts 40 to a total in which accumulation memory 62 stores, and then stores the stored total number of increments counted by the number of all the control parts 40 which corresponds to the number of Cleaning devices 4-1, 4-2, etc. corresponds, divides and thereby an average value, which is passed from the comparison part 60 in the form of the increment total number set value to all control parts 40. The control parts 40 form therefrom the difference signal between this increment total number set value and the actual value of the total number of counted increments of their summation counter 50.

Preferably, the corrected control signal setpoint is limited to a minimum value, in order to ensure that the cleaning cloth 12 in each according to a feed step provided for a cleaning program is actually further transported by a predetermined minimum number of increments. This ensures that at each provided according to the cleaning program feed step actually a cloth feed takes place and thereby a fresh tissue section is applied to the printing press cylinder 6-1 and 6-2, even if the calculated difference signal results in a corrected control signal setpoint at which no cloth feed would take place at the next feed step.

Claims (15)

1. Cloth feed control device of a cleaning device for printing press cylinders, the cleaning device (4-1, 4-2) being designed for the rotatable mounting of two cloth rolls (8, 10), of which one is a clean cloth roll (8) and the other is a dirty cloth roll (10), and it being possible for the dirty cloth roll (10) to be driven step by step by an automatic drive device (11) in order to transfer the cleaning cloth (12) step by step, by in each case a predetermined cloth feed length corresponding to a cloth feed length setpoint, from the clean cloth roll (8) to the dirty cloth roll (10), the roll diameters of the two cloth rolls changing;
   the cloth feed control device having the following: a control part (40), in which the cloth feed length setpoint (42) can be stored or is stored; a distance sensor (30) which operates without contact and which is designed to generate signals as a function of radial distance changes of the outer circumference of one of the two cloth rolls (8, 10) from the distance sensor (30), the distance sensor (13) being positioned or capable of being positioned at a predetermined radial distance from the axis of rotation of the cloth roll (8, 10), radially with respect to the axis of rotation, so that the signals correspond to the respective radius of the cloth roll (8, 10);
   characterized in that
   the distance sensor (30) is designed to generate signals linearly proportional to the radial distance changes of the outer circumference of one of the two cloth rolls (8, 10) from the distance sensor (30); in that the control part (40) is designed in such a way that it calculates the respective circumferential size of the cloth roll (8, 10) from the signals from the distance sensor (30) which correspond to the respective radius; in that, in the control part (40), in which a cloth feed length setpoint (42) can be stored or is stored, a predetermined number of rotational angle increments for the 360° circumference of the cloth roll (8, 10) is also stored; the control part (40) being designed to calculate by how many increments the cloth roll (8, 10) must be rotated in order, given the calculated circumferential size of the cloth roll, to transport the cleaning cloth by a cloth feed length corresponding to the cloth feed length setpoint by means of the drive device (11), and the control part (40) being designed to generate an actuating signal setpoint for the drive device (11) which corresponds to the calculated increments.
2. Cloth feed control device according to Claim 1,
   characterized in that
   the control part (40) is designed to round up beginning at a predetermined decimal number and to round down below the predetermined decimal number, in each case to an integer number of increments for the case in which the calculation of the increments does not result in an integer number, and the control part (40) being designed to generate a correspondingly rounded-up or rounded-down actuating signal setpoint.
3. Cloth feed control device according to Claim 1,
   characterized in that
   the control part (40) is designed to round up decimal numbers to an integer number in each case for the case in which the calculation of the increments does not result in an integer number, and the control part (40) is further designed to generate a correspondingly rounded-up actuating signal setpoint.
4. Cloth feed control device according to Claim 1,
   characterized in that
   the control part (40) is designed to round down decimal numbers to an integer number in each case for the case in which the calculation of the increments does not result in an integer number, and the control part (40) is further designed to generate a correspondingly rounded-down actuating signal setpoint.
5. Cloth feed control device according to one of the preceding claims,
   characterized by
   an encoder (44) for detecting rotational angle increments of one of the two cloth rolls (8, 10), the encoder generating an electric signal at each rotational angle increment detected by it and supplying the said signal to the control part (40), the control part (40) switching off the cloth feed during a cloth feed step when the signals from the encoder correspond to the actuating signal setpoint.
6. Cloth feed control device according to Claim 5,
   characterized in that
   the encoder (44) has increment markings (45) which are arranged distributed over 360° about the axis of rotation of a rotational element (46) which rotates synchronously with the cloth roll (8, 10), corresponding to the increments of the cloth roll (8, 10).
7. Cloth feed control device according to one of the preceding claims,
   characterized in that
   the control part (40) has a summing counter (50) for counting the total number of increments by which the cloth roll has been rotated since a first start.
8. Cloth feed control device according to Claim 7,
   characterized in that
   the control part (40) is designed to generate a difference signal from the difference between the actual value of the total number of counted increments from the summing counter and an increment total number setpoint and, furthermore, to generate a corrected actuating signal setpoint in the event that the difference signal deviates from a predetermined permissible difference value.
9. Cloth feed control device according to one of the preceding claims,
   characterized in that
   the distance sensor is an ultrasonic sensor.
10. Control device combination, containing two or more cloth feed control devices (2-1, 2-2) according to one of the preceding claims for correspondingly two or more cleaning devices (4-1, 4-2) of a printing press,
    characterized by
    a comparison part (60), which has a summing memory (62) and is connected to the summing counter (50) of the control parts (40) of all cloth feed control devices (2-1, 2-2) and counts the total number of counted increments from all the summing counters (50) and stores them in the summing memory (62), and in that, furthermore, the comparison part (60) is designed to divide the total number of all the counted increments from all the control parts (40) by the number of control parts (40) of all the cleaning devices and to calculate an average value corresponding to the result of the division as an increment total setpoint, which is fed to all the control parts (40).
11. Control device combination according to Claim 10,
    characterized in that
    the corrected actuating signal setpoint is limited to a minimum value which ensures that, during each feed step provided in accordance with a cleaning program, the cleaning cloth is actually transported onward by a predetermined minimum number of increments.
12. Printing press cylinder cleaning system, containing at least one cleaning device for at least one printing press cylinder,
    characterized by
    at least one cloth feed control device (2-1, 2-2) according to one of the preceding claims.
13. Cloth feed control method for the cloth feed of a cleaning cloth from a clean cloth roll to a dirty cloth roll in a cleaning device for cleaning printing press cylinders,
    by means of a distance sensor (30) which operates without contact and which generates signals as a function of radial distance changes of a cloth roll circumference from the distance sensor (30), the radial distance to the circumferential surface of one of the two cloth rolls, preferably the clean cloth roll, being detected and, from this, a signal corresponding to the radius of the cloth roll being formed;
    characterized in that
    by means of the distance sensor (30), preferably by means of an ultrasonic sensor, the signals are generated linearly proportional to the radial distance changes of the cloth roll circumference from the distance sensor (30); in that, by using this signal corresponding to the radius, the cloth circumference is calculated automatically by a control part (40); in that, in the control part (40), a cloth feed length setpoint is stored and a predetermined number of rotational angle increments for the 360° circumference of the cloth roll (8, 10) is stored;
    in that, by means of the calculated cloth circumference, it is automatically calculated by how many angular increments the cloth roll must be rotated by means of a drive device in order, in each case during a cloth feed step provided by a cleaning program, to move the cleaning cloth onward from the clean cloth roll to a dirty cloth roll by a predetermined feed length corresponding to the cloth feed length setpoint.
14. Cloth feed control method according to Claim 13,
    characterized in that
    by means of an encoder (44), the rotational angle increments of at least one of the two cloth rolls (8, 10) are detected, and the actual summed value of the detected rotational angle increments is stored in a summing memory (50) of the control part (40).
15. Cloth feed control method according to Claim 14,
    characterized in that
    from two or more cleaning devices in a printing press, the stored actual summed value from all the summing memories (50) is added automatically and, by dividing the total summed value by the number of cleaning devices, an average setpoint for the number of increments already covered is calculated;
    in that for each cleaning device, the difference between this average setpoint and the actual summed value of the rotational angle increments covered is formed and the difference value is stored;
    and in that, in the event of a deviation of the difference from a defined limiting value on one or more of the cleaning devices, during at least one of the next cloth feeds on the relevant cleaning device, the difference is at least partially automatically compensated for by means of corresponding automatic changing of an actuating value for the cloth feed drive.

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