Method for operating a printing press

Abstract

The invention relates to a method for operating a printing press (1) having an ink mechanism (6) which is cleaned, then provided with a roll protection agent and then operated in an ink-free state without printing ink. Continuously or periodically at short intervals, a programmed control device (9) checks on the basis of data on past and / or present and / or future operating conditions: when roll protection agent is to be introduced into the ink mechanism (6); and, as a result of this check, automatically introduces roll protection agent into the ink mechanism (6) or informs the operator of a recommendation for introducing roll protection agent into the ink mechanism (6).

Description

Technical Field

[0001] The present invention relates to a method for operating a printing press having an ink mechanism, which is cleaned, then a roller protectant is applied, and then the press is operated in an ink-free state (without printing ink). Background Technology

[0002] In practice, in this method, the roller protectant is manually sprayed, dripped, or applied to the ink mechanism by the operator to prevent damage to the rubber sleeves of the ink mechanism rollers due to dry running.

[0003] EP 1 717 032 B1 states that it is common practice to prevent dry running by having a lubricant, known as a lubricant, applied by hand by an operator to dry-running roll sections. In this context, bypass oil, bypass paste, and bypass spray are mentioned as examples of lubricants. Summary of the Invention

[0004] The objective of this invention is to provide an alternative method for operating a printing press.

[0005] The task is solved by a method for operating a printing press having an ink mechanism that is cleaned, then fitted with a roller protectant, and then operated in an inkless state—without printing ink—characterized by a programmed control device that continuously or periodically checks at very short intervals, based on data regarding past and / or present and / or future operating conditions, when to introduce the roller protectant into the ink mechanism; and automatically introduces the roller protectant into the ink mechanism or notifies the operator of a recommendation for introducing the roller protectant into the ink mechanism based on the result of the check.

[0006] The advantage of this invention is that it frees operators from monitoring tasks.

[0007] An added advantage is that it prevents machine damage with greater reliability.

[0008] Various expansion options are possible:

[0009] The control device can take into account predetermined limit values ​​during inspection.

[0010] The limit value can be stored in the control device.

[0011] The limit value can be the upper limit value.

[0012] The limit value can be the maximum permissible number of machine revolutions in an inkless state with an ink mechanism.

[0013] The control device can take into account at least one actual state of the printing press during inspection.

[0014] The actual state can be the number of machine revolutions completed since the last cleaning.

[0015] The actual state can be the number of machine revolutions completed using an inkless ink mechanism.

[0016] The actual state can be the number of machine revolutions completed by the ink guiding mechanism.

[0017] The data on past and / or present and / or future operational status may include data from the print job list. Attached Figure Description

[0018] Extended solutions can also be derived from the following description of the embodiments and accompanying drawings, in which:

[0019] Figure 1 A schematic diagram of a sheet-fed printing press is shown;

[0020] Figure 2 One embodiment is shown in which the cleaned ink unit is not used in the next brush stroke;

[0021] Figure 3 One embodiment is shown in which the cleaned ink unit is not used in multiple printing processes;

[0022] Figure 4 One embodiment is shown in which ink inflow is performed after a printing process;

[0023] Figure 5 One embodiment is shown in which a first job is set to the job list after a printing process;

[0024] Figure 6 One embodiment is shown in which a first job is set to the job list during a printing process;

[0025] Figure 7 One embodiment is shown in which a second job is set to the job list;

[0026] Figure 8 One embodiment is shown in which multiple jobs are set to a job list;

[0027] Figure 9 One embodiment is shown in which a job in the job list is moved. Detailed Implementation

[0028] Figure 1A printing press is shown, having printing units 1 to 5 for offset printing on sheets that pass through the sheet printing press in a transport direction T during printing operations. Each printing unit 1 to 5 has an ink unit 6, which includes rollers that roll over each other, the rollers partially having rubber sleeves. Next to the ink unit 6 are respectively provided input devices 7, such as spraying or dripping devices, for liquid or paste-like roller protectants, and cleaning devices 8, which are connected to a control unit 9, in which a program runs on a computer.

[0029] This printing press can also be used to perform the following printing operations in which one of the printing mechanisms 1 to 5, for example, printing mechanism 5, is not printing. In this printing operation, the ink mechanism 6 of the inactive printing mechanism 5 operates without feeding printing ink onto the rollers. Before this, the remaining ink left on the rollers by the previous printing task must be removed by means of the cleaning device 8. Otherwise, the rheological properties of the ink (which is not continuously renewed as in printing through input and output) will deteriorate, leading to subsequent problems in the ink mechanism 6.

[0030] After cleaning, the rollers cannot roll on top of each other for extended periods during dry runs, thus preventing damage to the rubber sleeves due to wear and the like without being "lubricated by printing ink." Therefore, if the control device 9 checks and calculates that the dry run duration is too long or there is a risk of prolonged dry run, it introduces roller protectant into the ink mechanism 6 via the input device 7. The control device 9 can make the above diagnosis based on the printing operation data stored therein.

[0031] The rollers are only allowed to roll a predetermined number of times on each other. This number corresponds to the total number of machine roller revolutions, which refers to the number of revolutions of the printing press cylinders, such as the plate cylinder 10. These machine revolutions are counted during the continuous printing of the sheets as they are fed through the printing press and during idle runs without sheet feeding. The plate cylinder 10 is a so-called single-speed cylinder, which performs one full revolution for each sheet being printed. The control device 9 performs the aforementioned checks periodically, for example, every 50 ms, according to the program in which it operates, and thus performs them approximately continuously.

[0032] Based on the inspection results, control device 9 can trigger the automatic introduction of roller protectant when needed, or notify the operator to introduce roller protectant, for example, through an optical display on the control panel of control device 9. In many cases, multiple printing units of the printing press can even be simultaneously deactivated and roller protectant supplied accordingly when handling printing jobs, especially when the printing press includes more than five printing units 1 to 5 shown.

[0033] According to the procedure, the control device 9 considers the actual state of the relevant printing mechanism 5 when planning the introduction of the roller protectant. This actual state includes the number of machine revolutions already completed in the previously cleaned ink mechanism 6, with and without the roller protectant. Furthermore, the control device 9 considers a limit value predetermined in the control device 9 or user-settable on the control device. This limit value represents the number of machine revolutions from which the roller protectant should be introduced at the latest. If the printing mechanism 5 should not be used for printing multiple directly following printing jobs (where the total print volume height exceeds the stated limit value), the control device 9 suggests or triggers the introduction of the roller protectant for the first printing job.

[0034] Furthermore, the actual state includes whether the roller protectant has been removed from the ink mechanism through cleaning. Moreover, the actual state also includes whether ink inflow is occurring or configured in the ink mechanism 6 (if the ink mechanism was not used in previous printing operations).

[0035] Furthermore, according to the program running in the control device 9, the control device 9 controls the data of printing jobs already existing in the digital job list. Here, the sequence of printing jobs, the print run height of printing jobs, and / or the status of printing units are taken into consideration. When considering the print run height, the control device 9 adds up the number of pages (for which printing unit 5 should not be used) across the printing jobs listed in the digital job list. When considering the status of printing units, the control device 9 diagnoses the status of printing unit 5 across the waiting printing jobs based on job data, such as the correspondence of different printing inks for printing units 1 to 5.

[0036] When one or more of the following changes are made, control device 9 re-implements the check and, if necessary, updates the settings for introducing roller protectant for all printing jobs in the job list:

[0037] - The actual condition of the printing press has changed.

[0038] - Add the new print job to the job list.

[0039] - Move a print job from one location in the job list to another.

[0040] - Delete a print job from the job list.

[0041] - Change the print run height of a print job in the job list.

[0042] - For printing jobs in the job list, change the correspondence between ink and printing mechanism.

[0043] The operator can configure the control device 9. For example, the operator can activate or deactivate recommendations for the introduction of roller protectant for one or more printing units. Similarly, the operator can input limit values ​​for height. The operator can also manually adjust the recommendations of the control device 9.

[0044] Figure 2 A programmable operation plan for a printing press is shown, wherein the cleaned ink mechanism is not used in subsequent printing. In step 21, the ink mechanism 6 of printing unit 5 is cleaned, wherein in step 210, the programmed counter for machine revolutions is reset to zero. In step 22, the printing press operates in an empty run without sheet feed, wherein the counter is activated according to step 220. In step 23, the printing press operates in continuous brush operation, wherein the cleaned ink mechanism 6 of printing unit 5 operates together without activation. Here, in step 230, the control device 9 determines that the counter value is greater than the limit value during this period. Because the number of machine revolutions performed in the inkless state of ink mechanism 6 has exceeded the permissible limit, the operator is instructed according to step 24 to introduce roller protectant into the unused ink mechanism 6. This can be done fully automatically or manually by the operator or by activating the input device 7 by pressing a button on the control panel of the control device 9.

[0045] Figure 3 A programmable execution plan for operating a printing press is shown, wherein the cleaned ink mechanism is not used in multiple printing processes. In step 31, the ink mechanism 6 of printing mechanism 5 is cleaned, wherein in step 310, the programmed counter for the number of machine revolutions is reset to zero. In step 32, the printing press operates in the first continuous run, wherein the counter is activated according to step 320 and its value increases with each machine revolution. In step 33, the printing press operates in an idle run, wherein the counter is still activated in step 330 and the control device 9 determines that the counter value is less than the limit value. In the first continuous run, the number of machine revolutions has not yet exceeded the permissible limit. In the next step 34, the printing press is in a stopped state, wherein the counter is deactivated and its value is maintained according to the corresponding step 340. In step 35, the printing press operates in the second continuous run. Here, the counter is reactivated according to the corresponding step 350. In step 351, the counter value exceeds the limit value. Because the number of machine revolutions performed in the inkless state of ink unit 6 during the second brushing has exceeded the permissible limit, the operator is required, according to step 36, to introduce roller protectant into the unused ink unit 6.

[0046] Figure 4A program execution plan is shown, in which ink inflow is implemented after a printing process. The following scenario is shown: before the number of machine revolutions exceeds a limit, the re-brush is terminated and ink is introduced into a previously unused mechanism. Specifically, the printing press operates as follows: In step 41, the ink mechanism 6 of printing mechanism 5 is cleaned. Step 410 includes: resetting the counter to zero in relation to the cleaning of ink mechanism 6. Then, in step 42, the printing press is run in a first re-brush, where the cleaned ink mechanism 6 is not used. In the first re-brush, according to step 411, the counter is activated, and according to step 420, the number of machine revolutions counted by the counter does not exceed the limit value stored in control device 9, therefore it is not necessary to introduce roller protectant into ink mechanism 6. In step 43, the first re-brush ends, and in step 44, ink is inflowed into ink mechanism 6. As ink flows in, the counter is reset to zero in step 440. In step 45, the printing press is run in a second re-brush, in which printing mechanism 5 and its ink mechanism 6 are actively engaged. However, in this second brush stroke, the counter is not activated according to step 450. Because the printing ink is present in the ink unit 6 during the second brush stroke, it is not necessary to monitor the number of dry-run machine revolutions using a counter.

[0047] Figure 5 Similarly, a program execution plan is shown, which has method steps implemented by the printing press and program steps implemented by the control device 9. In this example, a predetermined limit has not been exceeded at the end of the printing process. Then, a job is set to the digital job list. Because the sum of the counter reading reached during the printing process and the set print volume height of the job exceeds the predetermined limit, the introduction of roller protectant is suggested or triggered by the control device 9. Accordingly, the ink mechanism 6 of the printing unit 5 is cleaned by means of the cleaning device 8 in step 51, and the counter is zeroed in step 510. In step 52, the printing press is switched to continuous printing, and the counter in the control device 9 is activated in the relevant step 520. During continuous printing up to step 53, the counter counts the number of machine revolutions completed. With the end of continuous printing in step 53, the counter with a determined counter reading below the limit value is deactivated in step 530. Then, in step 54, a job with a determined number of pages or print volume height is set to the digital job list. The sum of the determined counter reading (step 53) and the determined print volume height (step 54) is compared with the limit value in step 540 and is higher than the latter. Therefore, as a result of the check, the control device 9 determines that the roller protectant should now be introduced into the ink mechanism 6 by means of the input device 7 (step 55). The advantage is that the queued printing operations do not need to be interrupted during their implementation to introduce the roller protectant.

[0048] Figure 6 A program execution plan is shown in which a job is added to the job list during the current re-brush period. Here, during this re-brush period, the predetermined limit for the number of machine revolutions allowed in the dry operation of the ink mechanism is not exceeded. The print volume of the queued jobs is only considered together at the end of the re-brush. Specifically, the subsequent steps are performed as follows: In step 61, the ink mechanism 6 of the printing unit 5 is cleaned with the cleaning device 8, since the ink mechanism 6 does not participate in the implementation of subsequent printing jobs and only operates here without ink delivery. Due to the cleaning instruction, the control device 9 sets the counter for machine revolutions to zero in the program running in the control device (step 610). In step 62, the printing press switches to re-brush, and here the counter is activated in the parallel step 620. In step 63, a new job is introduced into the job list, which should be completed as the next job after the current job. The re-brush is ended using step 64. Step 630 is performed consecutively between steps 62 and 64, and this step involves comparing the corresponding current value in the counter with a pre-given limit value. This comparison is repeated at small intervals until the end of the printing cycle (step 64). During this comparison, the planned number of pages (print height) for the print job set in step 63 is not considered in the phase between steps 63 and 64. Each time this comparison is performed, the counter value is found to be less than the limit value. In step 640, a new comparison is performed only after the end of the printing cycle, in which the sum (formed by the counter reading reached at the end of the printing cycle and the print height of the queued print jobs) is compared with the limit value. If the sum is greater than the limit value, the introduction of a roller protectant is caused in step 65. The advantage is that the queued print jobs do not need to be interrupted during their implementation to introduce the roller protectant.

[0049] Figure 7An example is shown in which multiple printing jobs are set into a digital job list in the control device 9. In step 71, the ink cleaning mechanism 6 is cleaned and the counter is zeroed in the corresponding step 710. In step 72, the printing press operates in continuous brushing, and the counter operates in conjunction with it in step 720. In step 73, continuous brushing ends, and the counter is stopped in step 730 accordingly. After continuous brushing ends, the first (job) is set into the job list in step 74. The comparison performed in the corresponding step 740 shows that the sum of the counter reading reached in continuous brushing and the planned print volume height of the first job is less than the limit value, and therefore roller protectant is not yet needed. Then, in step 75, another (second) job is set into the job list. Now, the check performed by the control device 9 in step 750 shows that the sum of the counter reading reached in continuous brushing, the planned print volume height of the first job, and the planned print volume height of the second job is greater than the limit value, and roller protectant needs to be introduced from now on.

[0050] Figure 8 An example of an implementation method is shown based on a program execution plan, in which multiple print jobs are set into a list of digital jobs.

[0051] The initial state is obtained in step 80 of the operating method and step 800 of the program run in the control device 9 for this purpose. Step 80 corresponds to the actual state of the printing press after a printing job has just been completed, in which the ink mechanisms of printing units 1 to 4 are activated and supplied with printing ink. The ink mechanism 6 of printing unit 5 operates inactively during this printing job without roller protectant, that is, during dry operation, for a number of machine revolutions corresponding to the counter reading z. Therefore, in the illustration of step 80, only the activated printing units 1 to 4 are shown, and the activated printing unit 5 is not shown. In step 800, the control device 9 determines during a check that the counter reading is less than a limit value (from which roller protectant needs to be introduced into the ink mechanism 6).

[0052] In step 81, printing job A with a print run of 'a' is added to the task list. Print run 'a' is the number of pages to be printed for printing job A and therefore the number of machine rotations to be performed in that printing job A. In this printing job A, the ink mechanism of printing unit 5 should not be used. Therefore, in step 810, it is checked whether the sum of the counter reading 'z' reached by the previous printing job and the print run 'a' is greater than a limit value. Since this is not the case and the sum is less than the limit value, the introduction of roller protectant into the ink mechanism 6 of printing unit 5 is not recommended or triggered.

[0053] In step 82, another printing job with print volume b is added to the job list. In this other printing job, printing mechanism 5 is not activated and ink flows into the ink mechanism 6 of printing mechanism 5. Therefore, the check performed in step 82 concludes that roller protectant does not need to be introduced into ink mechanism 6 for job B.

[0054] In step 83, printing job C with print volume c is added to the job list, and in step 84, printing job D with print volume d is added. The checks performed by control device 9 in steps 830 and 840 respectively show that the sum of print volumes c and d exceeds a limit. In this case, the sum of print volumes of multiple directly following printing jobs exceeds the limit. Therefore, for the first printing job of these multiple printing jobs (here, printing job C), the roller protectant has already been introduced into the ink mechanism 6 of the printing mechanism 5.

[0055] Figure 9 This shows a program execution plan for a run method in which a print job in the job list is moved.

[0056] The initial state is given in step 90 of the operating method and step 900 of the program running in the control device 9 for this purpose. Step 90 corresponds to the actual state of the printing press just after completing a printing job, in which the ink mechanisms of printing units 1 to 5 are activated and supplied with printing ink. Therefore, the ink mechanism 6 of printing unit 5 is also activated and supplied with ink, so according to step 900, it is not necessary to introduce roller protectant into ink mechanism 6 and the counter reading is set to z = 0.

[0057] In the digital job list of the control device, printing jobs are initially in the order A, B, C, and D shown in steps 91 to 94 on the left. Printing mechanism 5 prints in printing jobs A and D, but does not print in printing jobs B and C. The ink mechanism 6 of printing mechanism 5 guides ink in printing jobs A and D and operates together in an inkless state in printing jobs B and C. Printing jobs A to D have print volumes a to d. In step 910 of the procedure, it is determined that for printing job A in step 91, it is not necessary to introduce roller protectant into the ink mechanism 6 of printing mechanism 5, because ink mechanism 6 guides ink. In steps 920 and 930, control device 9 determines, respectively, that printing mechanism 5 is not activated in job B or C, and its ink mechanism 6 operates together without ink, and therefore the sum of print volumes b and c of the two directly following printing jobs B and C must be compared with a limit value. Here, the comparison concludes that the sum exceeds the limit and therefore the roller protectant should be introduced into the ink mechanism 6, which should be done in the first printing operation of the two directly following printing operations B and C, i.e., in printing operation B. In step 940, corresponding to step 94, the control device 9 determines that the ink mechanism 6 guides the ink in printing operation D because the printing mechanism 5 is actively involved in printing operation D; and accordingly, it is not necessary to introduce the roller protectant into the ink mechanism 6 for printing operation D.

[0058] Starting from the above sequence, the operator inputs movement 2000 on the control panel of the control device 9, which allows printing job D to be performed from the last position to a position between printing jobs B and C. This movement 2000 results in a new job list displayed on the control panel, in which printing jobs are now in the sequence A, B, D, and C as indicated by steps 101 to 104 on the left. According to the program running in the control device 9, the necessity of introducing roller protectant into the ink mechanism 6 of the printing unit 5 must be rechecked for all printing jobs in the job list. This also applies to changes in the job list where additional printing jobs are inserted between two printing jobs in the job list or where printing jobs are removed from the job list.

[0059] The descriptions already given in steps 91 and 910 also apply to steps 101 and 1010 in a transitive sense. In printing operation B, the printing mechanism 5 and its ink mechanism are not activated, therefore in step 1020 it is determined by the control device 9 that the print volume b is below the limit value z and therefore it is not necessary to introduce roller protectant into the ink mechanism 6. In printing operation D, the printing mechanism 5 operates actively, with ink flowing into its ink mechanism 6, therefore it is not necessary to introduce roller protectant. In the last printing operation C, the printing mechanism 5 and its ink mechanism 6 are again deactivated, therefore in step 1040 it is determined by the control device 9 that the print volume c is below the limit value z and therefore it is not necessary to introduce roller protectant into the ink mechanism 6.

[0060] List of reference numerals

[0061] 1. Printing facility

[0062] 2. Printing facilities

[0063] 3. Printing facilities

[0064] 4. Printing facilities

[0065] 5. Printing facilities

[0066] 6. Ink Mechanism

[0067] 7 Input Device

[0068] 8. Cleaning device

[0069] 9. Control device

[0070] 10 printing plate cylinders

[0071] Steps 21-1040

[0072] 2000 Mobile

[0073] A printing job

[0074] B Printing Operation

[0075] C Printing Operation

[0076] D Printing Operation

[0077] a print run

[0078] b Print run

[0079] c Print run

[0080] d Print run

[0081] T conveying direction

[0082] z Counter reading.

Claims

1. A method for operating a printing press (1) having an ink mechanism (6), the ink mechanism being cleaned, then fitted with a roller protectant, and then operated in an ink-free state—without printing ink—characterized by, The programmed control device (9) continuously or periodically checks at very short intervals, based on past and / or present and / or future operating data, when to introduce roller protectant into the ink mechanism (6); Based on the results of the inspection, the roller protectant is automatically introduced into the ink unit (6) or the operator is notified of the recommendation for introducing the roller protectant into the ink unit (6); The control device (9) takes into account a predetermined limit value (z) during the inspection. The limit value (z) is stored in the control device (9); The limit value (z) is the upper limit value; and The limit value (z) is the maximum permissible number of machine revolutions in an inkless state with an ink mechanism.

2. The method according to claim 1, characterized in that, The control device (9) takes into account at least one actual state of the printing press during inspection.

3. The method according to claim 2, characterized in that, The actual state refers to the number of machine rotations completed since the last cleaning.

4. The method according to claim 2 or 3, characterized in that, The actual state refers to the number of machine revolutions completed using an inkless ink mechanism (6).

5. The method according to claim 2 or 3, characterized in that, The actual state is the number of machine revolutions completed by the ink guiding mechanism (6).

6. The method according to any one of claims 1 to 3, characterized in that, The data on past and / or present and / or future operational status includes data from the print job list.

Images