EP2279974A1 - Method for controlling a paper-processing machine - Google Patents

Abstract

The method involves detecting an error i.e. serial error, using detection units (8, 9) i.e. optical sensors e.g. fault sheet sensor, during occurrence of the error. A measure is met in an automatic manner to act against the error, after detection of the error, where reducing the speed of a paper processing machine (1) i.e. insertion machine, is provided as the measure. The measure is partially nullified, when the error is not occurred. The processing machine is completely stopped, after time duration or a certain number of machine clocks, when the error is detected by the detection units. An independent claim is also included for a device for implementing a method for controlling a paper processing machine.

Description

The invention relates to a method for controlling a paper-processing machine, wherein upon the occurrence of at least one fault, this is determined automatically with at least one detection means, so that the error can be eliminated.

Paper processing machines, such as insertion machines, gathering machines or saddle stitchers are comparatively complex and consist of different stations. They are operated at high power and the stations often have their own drives. For example, a plug-in machine can have many feeder stations. With these investors sheets are each deducted from a stack and fed, for example, a transport device with pockets. This can not be avoided that occasionally errors occur, so that, for example, no sheets are deducted from a pile, which is said to be false prints. Occur on a feeder at full production speed, for example, such misprints in a row, one speaks of a serie error. The number of false prints leading to a series error is usually adjustable.

In the event of a series error, an alarm is triggered and the machine is brought to a controlled stop. The detection of faulty prints is done with a missing sheet sensor, which is arranged in the withdrawal direction in front of the trigger device. If the machine is stopped, the operator of the system must inspect faulty investors. Sheets that caused the fault are removed manually and new settings may be made. Afterwards the machine has to be started again.

Due to the complete stopping of the paper-processing machine or of the investor, many incomplete, that is to say unusable, products are produced, which must be removed or completed in the further course of the further processing. The necessary repair of such errors takes time and causes a significant reduction in the net power of a machine. In addition, the resumption of production is a very critical process that can often lead to further consequential interruptions. Machines in which errors, and in particular series errors, which require a machine stop, can occur, for example, cutting machines, stackers, bar outriggers, transport devices or even other paper-processing machines.

The invention is based on the object to provide a method of the type mentioned, with which the disadvantages mentioned can be at least partially resolved. The method is intended to enable the net performance of a paper processing machine to increase and reduce the incidence of unusable printed products.

The object is achieved in the inventive method in that after the detection of the error automatically a measure is taken to counteract the error and that the measure is at least partially canceled if the error does not occur or that the machine is stopped completely if the error is still detected by the detection means after the expiry of a certain criterion. In the method according to the invention, therefore, a measure is initially taken when a series error occurs in order to counteract the error. Thus, the machine is not immediately stopped, as before, when an error or a serial error was detected. For fast running machines, like For example, inserters that are operated at up to 50,000 cycles / h, several seconds are required for a machine stop. During this time, more than 40 faulty printed products can be created. Instead, after a series error, the machine is given the opportunity to use the time required for a machine stop and to correct the error without triggering an alarm with the help of the counteracting measure. Such a measure excludes a manual intervention and concerns, for example, the reduction of the machine speed. Other possible measures, which can also be combined with one another, are the injection of compressed air into, for example, a sheet stack of a feeder magazine and the actuation of mechanical means, for example a vibration or oscillation of a machine part. It has been shown that after such a measure, the error in many cases no longer occurs after a short time and is thus corrected by the machine itself, without causing an alarm, the machine has stopped completely and the error must be corrected manually. This self-repairing effect is on the one hand generated by the fact that the machine speed is reduced at a machine stop. For example, a vacuum cleaner of a take-off device at half the production speed for the construction of the vacuum twice as much time. On the other hand, the sheet stack is moved or at least shaken by the take-off device as a result of the withdrawal attempts continued up to 40 while the machine is being decelerated. As a result, the probability increases significantly that printed sheets can be deducted again. An intervention by the operator is not necessary in a self-repair. This substantially relieves the corresponding persons. In the case of large systems, it is thus possible to avoid overstraining the operators by means of relatively large distances between individual fault-causing stations of a machine and frequent troubleshooting, as has hitherto sometimes been the case.

If, despite this self-imposed measure, the error within the given criterion can not be reversed by self-repair, then the machine stopped. The said criterion is, for example, a variable time duration stored in a control device of the machine or a number of machine cycles. For example, the machine will stop if the error is not resolved after five machine cycles. This number of machine cycles is usually in the range of 1 to 15 cycles.

Preferably, the engine speed is re-accelerated to the original engine speed when the error is canceled within said criterion. However, it is also conceivable that the machine speed is initially not increased to the original machine speed in order to reduce the probability of a repeated occurrence of the same error. If necessary, the speed can later be increased again to the original machine speed after a certain period of time. In particular, a gradual increase in the machine speed is possible.

According to a development of the invention, a station of the machine, such as a feeder, is placed in the crawlspace after the detection of the error. This station then runs asynchronously to the basic machine. The station will be accelerated again after a self-repair and synchronized with the basic machine. With such an extremely slow movement, an attempt is made to remedy the error, for example the faulty removal of a printed sheet. If it is possible to remedy the error, this station is synchronized again with the basic machine, which now also runs slower.

The detection means for detecting the error is, for example, a sensor, for example a false-arc sensor on a feeder. This is then preferably arranged in the withdrawal direction according to a take-off device. Thus, for example, can be detected particularly safe when sheets are faulty or not deducted. The number of false prints can thus be determined very secure. But instead of a sensor, too other detection means, such as mechanical means, such as a button conceivable with which, for example, false prints but also double prints can be detected.

According to a development of the invention, a statistic is kept, for example, in the control device during the term of the investor, how often and in what number Serieffehler arise. This enables a substantial optimization of the process and thus a further increase of the net output.

Fig. 1

Schematisch eine Ansicht eines Teils einer papierverarbeitenden Maschine,

Fig. 2

das Stoppen und wieder Anfahren einer Maschine im Fall eines Fehlers nach dem Stand der Technik anhand einer Geschwindigkeitskurve,

Fig. 3

eine Kurve gemäss Fig. 2, jedoch bei der Durchführung eines erfindungsgemässen Verfahrens,

Fig. 4

den Kurvenverlauf, gemäss einer Variante des erfindungsgemässen Verfahrens, bei welchem eine Station der Maschine in einen Kriechgang versetzt wird und

Fig. 5

den Kurvenverlauf gemäss einer Variante des erfindungsgemässen Verfahrens, bei welchem die Maschinengeschwindigkeit stufenweise erhöht wird

Fig. 6

eine Darstellung der Seriefehleranzahl anhand von zwei Kurven, die einen Fall A und einen Fall B betreffen.

Further advantageous features emerge from the dependent claims, the following description and the drawings. Showing:

Fig. 1

Schematically a view of a part of a paper processing machine,

Fig. 2

the stopping and restarting of a machine in the case of a fault in the prior art using a speed curve,

Fig. 3

a curve according to Fig. 2 but in carrying out a method according to the invention,

Fig. 4

the curve, according to a variant of the inventive method, in which a station of the machine is placed in a creeper and

Fig. 5

the curve according to a variant of the inventive method in which the machine speed is increased gradually

Fig. 6

a representation of the series error number based on two curves that relate to a case A and a case B.

In the Fig. 1 partially shown machine 1 is a plug-in machine having at least one feeder 2, with which of a stack 7 by means of a Deduction device 11 flexible, sheet-like objects, for example, folded sheet 10 withdrawn and fed to a transport device 4. The transport device 4 has pockets 5, in which the printed sheets 10 are stored. The Fig. 1 shows a sheet 10 a, which is just deducted from the stack 7 and now placed in one of the pockets 5. The stored printed sheets 10 are transported in a conveying direction 16. In general, several such investors 2 are provided with which each sheet 10 are stored in the pockets 5. So that sheet 10 can be collected or collected to a printed product, such as a newspaper, a magazine or a book block. Instead of the transport device 4 shown with the pockets 5 are here also other transport devices, such as those with a gathering chain or with grippers possible.

The withdrawn printed sheets 10 are detected with a detection means 8 and / or a detection means 9. Corresponding data are transmitted to a control device 3. Preferably, the detection means 9 is provided, which is arranged as seen in the withdrawal direction after the extraction device 11. The detection means 8 and 9, for example, an optical sensor. But there are also other detection means 8, 9, for example, mechanical or electrical detection means conceivable. The feeder 2 can thus have the first detection means 8 or the second detection means 9 or both. With the detection means 8 and 9 can be determined whether a sheet 10 was faulty or not deducted. The removal takes place in the machine cycle, for example by means of the extraction device 11, which has suckers not shown here. These suckers lift the lowermost sheet 10 from the stack 7, so that it can be detected and transported by grippers or take-off rollers in a known manner.

The machine 1 shown with the feeder 2 and the transport device 4 is merely an example of a machine in which the inventive Method is applicable. Instead of the investor 2, other stations 6 such as a glue, a cutting machine for cutting book blocks or a stapler may be provided. The method according to the invention can also be applied to a wide variety of machines 1, such as a stacker, rod jib, saddle stitcher, gathering machine and perfect binder. Here detection means are also possible or already known for error detection.

If a certain number of false prints or a series error is detected by the detection means 8 or 9, then an alarm has been triggered and the machine 1 has been stopped and the machine 1 has been stopped and a machine speed M1 has thus been lowered to zero. This is based on a curve 20 in the Fig. 2 shown. The Y axis here indicates the machine speed M and the X axis indicates the time T. False prints occurring within a period of time 17 cause a series error, as a result of which the control device 3 triggers an alarm and the machine 1 stops. A period of time 24 indicates the time necessary to stop the engine 1. When the engine 1 is stopped, the feeder 2 is inspected for a period of time 27 and the fault is searched and corrected. This period of time 27 depends on the type of error, but may be comparatively long, for example several minutes. It is conceivable that with larger disturbances, in which components are damaged, an exchange of the investor 2 takes place. Subsequently, the machine 1 is started again until the original machine speed M1 is reached. A period of time 26 is necessary to bring the machine 1 back to the original speed M1. The faulty printed products resulting during the period 24 must be rejected. The time required from the occurrence of the serial defect to the time of reaching the original production speed after a machine stop shows a period of time 25.

In the inventive method is as in Fig. 3 shown after the determination of a number of series errors during the period 17, the machine. 1 not stopped in principle. According to a curve 21 predetermined by the control device 3, the speed of the feeder 2 and the machine 1 is reduced. If, for example, at a point A of the curve 21 it is determined that due to a self-repair the feeder 2 correctly withdraws the printing sheet 10 again, the speed of the feeder 2 and the machine 1 is increased until the original machine speed M1 has been reached again. Such an increase of the machine speed can also be done later in a point B, if a self-repair later, for example. at a lower engine speed M2 occurs. If the error continues to be detected during a specific time period 31 after the occurrence of the serial error or at a predetermined, low engine speed M3, an alarm is triggered and the machine 1 is completely stopped according to the dashed curve 22. The machine must then in this case as in FIG. 2 presented and described above inspected and the error can be corrected. Subsequently, the machine 1 is then again according to Fig. 2 put into operation. In Fig. 3 the time 24 necessary for completely stopping the machine 1 is shown. A period of time 32 is required in order to reach the full production speed M1 again after the occurrence of the serial error, if it is determined in point A that the error has been rectified. A period of time 33 is required if it is determined in point B that the error has been eliminated. If there is no self-repair effect, the in Fig. 2 shown much longer time 25 required until the machine 1 is back in operation and the machine speed M1 is reached again. The criterion that determines when the machine 1 is stopped is, for example, a certain period of time, a number of cycles or the achievement of a certain, minimum machine speed M3.

Instead of, or in addition to, a reduction in machine speed, other measures may be taken to assist the self-repairing effect. For example, air can be injected with an air nozzle in a suitable area. Also possible is an in Fig. 1 schematically actuation of mechanical means 38 such as a device with which vibrations in a suitable area of the investor 2 can be exercised. Alternatively, for example, the suction of a sucker can be increased or an additional sucker can be activated. These measures will be discontinued if no self-repair effect is detected within the criterion. With these measures, the number of cases in which the machine 1 has to be completely stopped after the occurrence of a serial defect can be substantially reduced. Overall, the net power can be substantially increased. An increase in the net output is possible in particular if, according to the curve 21, the machine speed has to be reduced only very briefly, ie. the speed M1 is reached again after the comparatively short period of time 32. If the speed is increased after the point B, the time period 33 is longer, according to the curve 23, until the machine 1 has again reached the original speed M1. But even in this case, the interruption and also the waste paper waste is smaller than in the case of a complete stop. Corresponding repair work and the stress of an operator are also not required.

In the method according to the Fig. 3 behaves a station 6 such as the feeder 2 and the base machine 1 synchronously. However, it is also possible asynchronous behavior between the stations 6 and the basic machine 1, as shown by the Fig. 4 is shown. Shown is the method in case of self-repair. The curve 12 shows the speed profile of the investor 2. This is offset after the detection of a series error in the crawl. In creeper, the feeder 2 runs at a speed M4, which is for example 1000 cycles / h. For this asynchronous behavior, the feeder 2 and the base machine 1 must each have their own drive, for example a servo drive. At point A 'after a period of time 34 a self-repair is detected and then the machine speed of the feeder 2 and the machine 1 according to the curves 12 and 14 increases again until the initial speed M1 is reached. If it is determined only after a period of time 35 at point B 'that the feeder 2 withdraws again correctly, then the speed of the feeder 2 and according to the curve 14' the speed of the machine 1 are increased again in accordance with the curve 15. The speed of the feeder 2 is thus lowered considerably faster and to a lower value M4 than the speed of the machine 1 according to the curve 12. As soon as the feeder 2 can again process the printed sheets 10 without errors, it is synchronized with the machine 1. How out Fig. 4 is apparent, the synchronism between feeder 2 and the machine 1 is restored before reaching the original engine speed M1, the curves 14 and 12 are congruent in increasing the engine speed after the point A '. The same applies in the event that the self-repair takes place only in point B '. The curves 14 'and 15 are also congruent, ie the feeder 2 and the machine 1 are again in sync with each other and no other printed products must be discharged. By placing the feeder 2 in the crawlspace after a series error, the self-repairing effect is particularly strongly supported. The production can thus after the period 36 or 37, which is significantly shorter than the period 25 after Fig. 2 is to be continued with the original machine speed M1.

The leading to a series error number of errors can be fixed or variable in the control device 3. The measures mentioned that counteract an error are taken when the error persists, for example, after a corresponding number of deductions. For example, the machine speed is lowered when three misprints are detected. Preferably, this number is automatically adjusted during operation to an optimum value. Optimal here means that as few faulty printed products as possible are rejected, but the number of machine stops should be small and the net output should be large. In order to set this optimum value of the series error number, it is provided that during the term of the investor 2 by means of the control device 3 a Statistics is led, how often and how many serie errors occur. Based on these statistics, the optimal setting of the serial number of errors is determined.

It is further conceivable that the control device 3, the machine speed after a in Fig. 5 After a successful self-repair, the curve shown does not adjust to the original value M1 but to a lower value M5, at which fewer disturbances occur. This could further reduce the number of ejected, incomplete printed products. If there are no or very few misprints at the machine speed M5, the control device 3 could increase the speed in stages, thus seeking an optimum machine speed with respect to incomplete printed products and high net output.

The diagram in Fig. 6 represents two different error statistics by way of example. The serial error number S is shown on the X axis, and the number N of the series errors on the Y axis. A curve 18 represents a first case in which in most cases after one or two subsequent misprints the sheets are correctly processed again. In this case, for example, the serial error number is set to two here. If a printed product 10 can not be processed, so after only two errors following automatically a measure corresponding to the error is triggered so as to use a possible self-repair effect with as few faulty printed products and no machine stop.

In a second case shown with the curve 19, the sheets are apparently partially removed correctly only after several misprints in series again. In this second case, the serial number of errors is greater than in the first case, for example, the value six is used here. Thus, unnecessary machine stops can be avoided and yet only a manageable amount of printed products is generated and rejected incorrectly. In both cases, it is extremely rare that a printed sheet 10 can not be detected by the trigger device 11 in a feeder after several false prints. This can happen if, for example, an attached vacuum cleaner of the trigger device 11 is defective or dropped. A machine stop for a manual intervention is then necessary.

With the method according to the invention, not only errors such as the misprints described at the feeder 2 can be remedied automatically by introducing measures. Of course, double prints, in which two sheets are withdrawn together, by mechanical means 38, such as the automatic introduction of additional separating agents or the targeted injection of air into the stack, be repaired by self-repair.

In a multi-feeder system 2, 35 serial faults were found in one test during 3 hours of operation. In 28 cases, a self-repair effect occurred due to a short-term lowered machine speed. Only in 7 cases was a complete machine stop required. Accordingly, fewer alarms had to be triggered, which relieved the operator from unnecessary troubleshooting. Compared with the prior art could be significantly increased by the respective initiation of measures after a series error and by the self-repair effects occurring the net output and reduce the number of discharged printed products.

Claims (15)

Method for controlling a paper-processing machine (1), wherein upon occurrence of at least one error this automatically with at least one detection means (8, 9) is determined, so that the error can be corrected, characterized in that after the detection of the error automatically taken a measure is to counteract the error and that the measure is at least partially canceled when the error no longer occurs or that the machine is stopped completely when the error after a certain criterion continues to be detected by the detection means (8, 9). A method according to claim 1, characterized in that the error is a series error. A method according to claim 1, characterized in that the measure is a reduction in the machine speed. A method according to claim 3, characterized in that the machine speed according to a predetermined by a control device (3) curve (12, 14, 14 ', 15 21, 22, 23, 28) is changed. Method according to one of claims 3 or 4, characterized in that the engine speed is accelerated back to the original engine speed (M1) when the error within the said criterion is canceled. Method according to one of claims 1 to 5, characterized in that the measure comprises the actuation of mechanical means (38). Method according to one of claims 1 to 6, characterized in that after detecting the error, a station (6) of the machine (1) is placed in the creeper and that this station (6) accelerates and synchronized with the machine (1) again if it is determined within the stated criterion that the error no longer occurs. Method according to one of claims 1 to 7, characterized in that the error in a feeder (2) of a inserter, a collator or a saddle stitcher is detected. Method according to one of claims 1 to 8, characterized in that the detection means (8, 9) comprises at least one sensor. Method according to one of claims 1 to 9, characterized in that said criterion is a period of time. Method according to one of claims 1 to 9, characterized in that said criterion is a number of machine cycles. Method according to one of claims 1 to 11, characterized in that the measure is taken after a certain number of serial errors. A method according to claim 12, characterized in that said number of serial errors is optimized on the basis of statistics. A method according to claim 12 or 13, characterized in that the number of serie errors corresponds to a number of failed or double copies of an investor (2). Device for carrying out the method according to one of the preceding claims, characterized in that the machine (1) has means (38) for assisting a self-repair.

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