EP3118127B1 - Method for reliably operating a cigarette packing machine - Google Patents

Description

The present invention relates to a method for the safe operation of a packaging machine for producing packages for smokable products - such as cigarettes - wherein the packaging machine has at least one servo drive for driving at least one movable member. The invention further relates to a packaging machine which is suitable for carrying out the method. A cigarette packaging machine with servo drive is through DE 10 2008 051 779 A1 known. In cigarette packaging machines, movable organs are increasingly driven by servomotors. On a mechanical coupling of the movable organs with a vertical shaft of the machine via suitable transmission, etc. is increasingly dispensed with. Due to the use of servomotors, relevant safety questions must be answered. In particular, the servomotors must be safely shut down and / or shut down in the event of an error. Furthermore, it must be possible for an operator to be able to (safely) move the movable organs in a manual operation, for example in order to be able to remove packs which have been jammed in or through the organs.

Based on this, it is an object of the present invention to further develop the method mentioned. Furthermore, it is an object of the present invention to provide a packaging machine that can be operated with such a method.

The object according to the invention is achieved by a method having the features of claim 1 and by a packaging machine having the features of claim 11.

Thereafter, the servomotor may be operated in one of at least two modes of operation when the machine is first set up or after a machine stop. Namely, a first mode in which the actual rotational position of the servomotor (or its shaft / rotor) compared with a target rotational position and in case of deviations between the actual and target rotational position of the actual rotational position to the target at Adjusted rotational position. In other words, in this mode of operation of a control device of the packaging machine, usually the control unit of the servo drive, a known in the art attitude control of the servo drive implemented.

Such a position control, which would be specified as a target rotational position, for example, the stationary rotation of the shaft of the servomotor can, after a targeted shutdown of the servomotors or after a targeted stopping the servo motor shaft unwanted movements of the servomotor or operatively connected to him movable member from the stationary rotation prevent or at least counteract such. Because as a result of the position control, every possible outer, i. Not caused by the servo motor torque action on the shaft, which would lead to a twisting of the desired rotational position, counteract a counter-torque of the servomotor, which would move the shaft back towards the desired rotational position. Thus, in this situation, it is ensured, inter alia, that the movable member is still in the original standstill position when the packaging machine is restarted and would accordingly (continue to) move synchronously with the machine cycle. Next, the position control would counteract an unwanted startup of the servomotor.

In a second mode of operation of the servo drive, the controller releases the shaft of the servo motor so that an operator can move the servo motor shaft, in particular without the position control being activated. Also, no other mode (or separate brake, etc.) is selectively activated or adjusted that would prevent free movement of the shaft, such as a so-called secure stop or brake or the like. In the second mode, in particular, no position control is carried out, therefore, the shaft of the servomotor is freely movable, at least within one - if applicable, predetermined angle of rotation (less than 360 degrees) - or preferably within the entire range of rotation angle (over the full 360 degrees).

According to the invention, it is provided that the servo drive is automatically transferred from the aforementioned first to the second operating mode, when - while the servo drive is in the first operating mode - an (external) torque is applied to the shaft of the servomotor of the servo drive, in particular by an operator a torque of predetermined size. This makes it possible, for example, for an operator to selectively switch off the position control, for example for maintenance purposes, around the servomotor shaft or the movable member operatively connected to it (directly or indirectly by hand, possibly by means of a mechanical linkage operatively connected to the shaft) or electronic handwheel).

Alternatively or additionally, the invention provides that the servo drive can be transferred from the second to the first operating mode by the operator of the shaft of the servomotor is rotated by an operator until the shaft reaches a predetermined target rotational position.

In the scenario described above, for example, the operator could first switch off the position control (acting with the standstill rotational position as setpoint) by the described torque application of the shaft. With the position control switched off, he could then carry out maintenance or repair work on the then manually or freely movable organ. Finally, he could turn back the servomotor shaft in the then acting as a target rotational position of the second mode standstill rotational position to turn on the position control again. The operator would recognize that the servomotor shaft is again in the original standstill rotational position since further rotation would counteract the active position control.

Preferably, the above-mentioned application of the minimum torque is detected on the basis of a thereby increasing current increase of an operating current of the servo drive.

According to a further embodiment of the invention or as further concretized thereof, it is provided that the minimum torque of predetermined size is stored as a value in a memory, that the torque applied by the operator to the shaft is determined and compared with the minimum torque value stored in the memory, and that the servo drive in the event that the applied Torque corresponds to the stored minimum torque value, is transferred from the first to the second mode.

The minimum torque value is expediently a value greater than zero.

According to a further concretization of the invention it is provided that the predetermined target rotational position is stored as a value in a memory that determines the set by the operator by rotations rotational position and compared with the stored target rotational position, and that the servo drive in the event that the set Rotary position corresponds to the stored in the memory target rotational position is automatically transferred from the second to the first mode.

The aforementioned comparisons, etc., are preferably carried out by a control device of the packaging machine or the control unit of the servo drive.

Further features and effects of the present invention will become apparent from the appended claims, the following description of a preferred embodiment of the invention, as well as from the accompanying drawings.

Fig. 1

eine schematische Schrägansicht einer Zigarettenverpackungsmaschine, die in erfindungsgemäßer Weise betrieben werden kann,

Fig. 2

die Vorrichtung aus Fig. 1 in einer vereinfachten Seitenansicht,

Fig. 3

exemplarisch eine Situation, in der ein durch einen Servoantrieb bewegtes Organ der Maschine, nämlich ein Förderer, durch eine Packung blockiert ist,

Fig. 4

ein die Situation der Fig. 3 abbildendes, dem Servoantrieb zugeordnetes Drehmoment-/Drehwinkel-Diagramm,

Fig. 5

der Förderer gemäß Fig. 3 nach einer händischen Bewegung der Welle des den Förderer antreibenden Servomotors des Servoantriebs,

Fig. 6

ein der Fig. 5 zugeordnetes Drehmoment-/Drehwinkel-Diagramm des Servo-antriebs,

Fig. 7

eine Darstellung entsprechend Fig. 3 nach einer weiteren händischen Drehung der Servomotorwelle,

Fig. 8

ein der Fig. 7 zugeordnetes Drehmoment-/Drehwinkel-Diagramm des Servo-antriebs.

Show:

Fig. 1

a schematic oblique view of a cigarette packaging machine, which can be operated in accordance with the invention,

Fig. 2

the device off Fig. 1 in a simplified side view,

Fig. 3

exemplarily a situation in which an organ of the machine moved by a servo drive, namely a conveyor, is blocked by a packing,

Fig. 4

a the situation of Fig. 3 imaging, the servo drive associated torque / angle diagram,

Fig. 5

the conveyor according to Fig. 3 after a manual movement of the shaft of the servomotor of the servodrive driving the conveyor,

Fig. 6

one of the Fig. 5 assigned torque / angle diagram of the servo drive,

Fig. 7

a representation accordingly Fig. 3 after another manual rotation of the servomotor shaft,

Fig. 8

one of the Fig. 7 Assigned torque / angle diagram of the servo drive.

The invention is based on the in the Fig. 1 and 2 illustrated cigarette packaging machine 10 explained. The nature of the packaging machine ultimately does not matter according to the invention. The invention could also be applied, inter alia, to machines for packaging tobacco in pouches (bag packers) or other machines for packaging smokable products.

The illustrated device 10 is used to treat in particular cuboidal packs 11 of relatively rigid packaging material, in particular of (thin) cardboard. It is part of a corresponding plant for the production of (cigarette) packs 11.

The basic operation of such a device 10 will be briefly explained below with reference to the drawings. Further technical details are in the DE 10 2011 122 327 described, the content of which is hereby incorporated into the present application.

The concrete example relates to (cigarette) packs 11 in the form of a folding box or hanging lid pack. The package is surrounded on all sides by an outer sheath 12 made of film, which is thermally sealable - in the range of folding flaps - and by heat supply shrinkable (shrink film).

A blank of the outer cover 12 is folded around the package 11 or folding box so that a (large-scale) front wall, a corresponding rear wall, narrow, upright side walls and end wall and bottom wall arise. The outer sheath 12 is folded so that on a side wall (partially) overlapping folding flaps, namely hose tabs arise. The front wall and bottom wall are provided with complex folds (envelope folding) with the formation of (trapezoidal) closing flaps. The folding flaps are connected by thermal sealing.

Coming from a packer, to the outer casing 12 finished packages 11 are fed via an intermediate conveyor intermittently and at a distance from each other a folding device 13, namely a folding turret. This is preferably analogous to the folding turret EP 1 103 465 A1 educated. In the area of the folding turret 13, in particular the abovementioned tube tabs are formed and fixed by stapling members 14 in the sense of stapling (connection of the folding tabs by means of small sealing surfaces). The folding turret 13 is provided with successive (different) stapling members 14.

Following the folding turret 13, the packages 11 reach a horizontal conveying path 15 lying in a first (horizontal) conveying plane. The transport takes place by means of an (endless) conveyor 16 (belt conveyor). In this conveying section or along this conveying path 16, the packs 11 are transported through a suitable folding path for the production of the closing flaps. For this purpose, 16 folding switches of known design are arranged laterally next to the conveyor, which form the folding flaps during transport.

With the (completely) folded outer casing 12, the packs 11 reach the area of another work station, namely a stapling and shrinking station having a stapling and shrinking device. Here, the staples of the folding flaps of the packs 11 are supplemented or completed with stapling organs.

Superimposed with the staple is a (first) shrinkage treatment of the upwardly facing front wall of the package 11.

Subsequent to the stitching and shrinking station 17, the packs 11 are conveyed in the area of a further processing station 18 with an outer casing sufficiently fixed with regard to the folding flaps, namely to an aggregate station.

The aggregate station 18 serves on the one hand to form processing groups or processing units of several, in the present example exactly four, originally successively transported packs 11. Furthermore, the packs 11 in the region of the aggregation station 18 in a vertical conveying plane or along a vertical conveyor track transversely transported to the incoming conveying direction, in the present case vertically or in the upward direction. For this purpose, the packages 11 are transported by a number of vertical conveyors 19. This number of vertical conveyors 19 corresponds to the number of packs 11 (four) contained in one processing unit.

In the area of the aggregate station 18, on the one hand, the side walls of the packs 11 are shrunk, in each case several or all packs 11 of a unit at the same time. Furthermore, the folding flaps are connected in the region of the side wall by sealing.

Finally, a second sealing step is carried out in the area of the tube tabs.

The aggregate station 18 is equipped for this purpose with three workstations, wherein in each of these stations simultaneously several - in the present case four - packs 10 are processed during a standstill phase.

Subsequent to the aggregate station 18, the packs 11 are moved along a further conveying path 20 that runs horizontally and offset from the conveying path 15. Along the conveyor line 20, the packages 11 are fed by means of a conveyor 26 further treatment stations, and immediately thereafter a combined sealing and shrinking station 21. In the present case, therefore, the packages 11 of a processing unit in the area of this station 21 are sold at each working or conveying cycle. Here, the packs 11 are processed on different sides of the pack during a (longer) standstill phase.

In the sealing and shrinking station 21, lower large-area pack sides as well as further pack surfaces are processed, namely sideways areas - end wall, bottom wall. It's about sealing the complex folding flaps.

A subsequent transfer station 22 is used to transfer the transport of the packages 11 from the conveyor 26 to an end conveyor 24. For this purpose, the transfer station 22 is formed in a special way. Also in the area of the transfer station 22, the packs 11 are treated during the standstill phase. Lateral sealing organs complete the sealing of the folding flaps of the sideward-directed packing walls.

The packs 11 subsequently reach the area of a last treatment station 23. There, the tops of the packs 11 are subjected to a shrinkage treatment, in this case the front wall.

The finished treated packages 11 are then deposited on a discharge conveyor 25, which supplies the packages for further processing, in particular the production of bundle packs.

Furthermore, lateral sealing organs are effective, which are moved up again to the front wall and bottom wall to complete the sealing of the folding flaps.

All driven members of the device 10 are driven by servo drives, not shown. In each case one organ is assigned in each case a servo drive. Such as the folding turret 13 and the conveyors 16, 24-26. The servo drives are synchronized with each other and with respect to the machine cycle of the packaging machine 10. Accordingly, the movements of these moving bodies 13, 16, 24-26 are also synchronized or matched in speed and phase.

If there is a deliberate or unwanted machine stop of the packaging machine 10, for example because a package 11 is jammed in the conveyor 25 or in one of the other conveyors, the servo drives must be transferred to safe states. In the context of the invention, various safety functions of servo drives are used profitably.

Thus, in the event of a fault-related or a deliberate machine stop, the drives can be reliably brought to a standstill over a defined period of time as part of a defined braking process.

In the case of servo drives of movable organs, which are freely accessible to third parties or operators after opening a machine protection hood and represent a corresponding hazard, it is also important to take appropriate measures to ensure that they do not accidentally come to a standstill for the duration of the machine stop start.

Such a safety function may include, for example, a position control designed as a standstill monitoring. With this, the actual rotational position of the servomotor of the servo drive or the shaft is monitored during the standstill thereof or during the machine stop duration. The standstill rotation position forms the setpoint rotational position of the position control.

By means of a suitable position sensor, the actual position of the rotational position of the respective servomotor is detected (continuously or repeatedly at certain time intervals) and compared with the desired rotational position or the stationary rotational position. In case of deviations of the actual rotational position of the target rotational position of the corresponding servo drive reacts by applying the shaft with a torque which counteracts the deviation. In other words, an external, not initiated by the servo drive torque acting on the shaft, a counteracted by the servo drive counter torque.

Although this standstill monitoring or this position control with the standstill rotational position as a desired rotational position advantageously leads to the fact that the engine does not start by mistake can, because the position control would counteract the start. Further, an operator who wants to maintain the movable members at a standstill of the machine can not readily change the standstill rotational position of the servomotor or the standstill position of the movable member, which would liberate the movable member from its synchronism with the machine cycle and cause an error in the Restart the packaging machine 10 can lead.

However, the position control described at standstill of the servo drive is also disadvantageous in various situations. So there may be situations in practice, in which it would just be necessary to be able to move the movable organ by hand after a machine stop. For example, in a case where a trouble occurs that can be resolved only by moving the movable organ. An individual manual operation of the packaging machine or individual movable organs thereof, which is particularly necessary in order to eliminate such disturbances, would be limited.

For this reason, the invention provides for the operator to be able to switch off this position control in a simple manner. For this purpose, the servo drive is automatically transferred from the first "attitude control" mode described above to a second mode in which it no longer occurs when the operator applies torque to the servomotor servo motor shaft.

For example, it can be provided to deposit in the controller that a torque of a certain minimum size or a certain amount must be applied in order to switch off the position control or to change from the first operating mode to the second operating mode.

The torque can be applied by the operator by operating a movable handwheel connected directly to the shaft of the servomotor, for example, or a separate handwheel, which is electrically or electronically coupled to the shaft. If necessary, it is also sufficient to move the coupled to the shaft movable member accordingly.

The application of this torque is detected by the servo drive or the control thereof. As an indicator, for example, can serve a measured increase in current of the operating current of the servo drive, which adjusts, since the application of the outer Torque (due to the position control) is answered with a corresponding counter torque.

The scenario described above refers to a situation in which a machine servo motor was braked to a standstill during a machine stop, and then the controller selectively activates a position control related to the standstill rotational position.

• In Fig. 3 ist eine Situation gezeigt, in der eine Packung 11 zwischen dem Förderer 25 und einem angrenzenden Bauteil 27 eingeklemmt ist. Dies führt zu einem ungewollten Maschinenstopp. Insofern die Servoantriebe vor dem Maschinenstopp im Normal- bzw. Produktionsbetrieb der Anlage mit einer "Standard"-Lageregelung gefahren wurden, bei der das für das jeweilige bewegbare Organ jeweils gewünschte Bewegungsprofil (synchron zum Maschinentakt) durch Soll-Drehlagenvorgaben für den jeweiligen Servomotor vorgeben wird, und insofern diese Lageregelung auch bei dem in Fig. 3 gezeigten, ungewollten Maschinenstopp aktiviert bleibt (alternativ kann vorgesehen sein, dass die Lageregelung der Servoantriebe in einer solchen Situation automatisch inaktiv geschaltet wird), führt dies dazu, dass an dem Servomotor ein Drehmoment M anliegt, vgl. Fig. 4. Denn der Servoantrieb "arbeitet" gegen das Klemmmoment der Packung 11. Einem Bediener ist es entsprechend nicht oder kaum möglich, die verklemmte Zigarettenpackung 11 gemäß Fig. 3 durch Drehung des Förderers 25 entgegen der Förderrichtung zu befreien.

With reference to the following drawings of Fig. 3-8 another scenario is explained:

• In Fig. 3 a situation is shown in which a package 11 is clamped between the conveyor 25 and an adjacent component 27. This leads to an unwanted machine stop. Insofar as the servo drives were moved before the machine stop in normal or production operation of the system with a "standard" position control in which the respectively desired motion profile for the respective movable organ (synchronous to the machine cycle) by target rotational position specifications for the respective servomotor , and insofar as this position regulation also in the Fig. 3 shown, unwanted machine stop remains activated (alternatively, it can be provided that the position control of the servo drives is automatically switched inactive in such a situation), this leads to the fact that a torque M is applied to the servo motor, see. Fig. 4 , Because the servo drive "works" against the clamping torque of the pack 11. An operator is not or hardly possible, the jammed cigarette packet 11 according to Fig. 3 free by rotation of the conveyor 25 against the conveying direction.

Even in such a situation, it may be desired that the operator can turn off the attitude control of the drive in a simple manner, in order to move the shaft of the servo motor free of counter torques and to be able to easily remove the packing 11. For this purpose, the operator must apply an external, additional torque to the servomotor or on its shaft, cf. Fig. 6 , This can be done for example by using a coupled to the shaft of the servo motor 28 handwheel.

After switching off the position control can in the example of the Fig. 3-8 the conveyor are moved counter to the conveyor direction, cf. Fig. 5 so that the pack 11 is free.

However, the rotational movement of the conveyor 25 initiated by the operator also results in the result that the rotational position of the servomotor of the conveyor 25 is no longer synchronous with the rotational positions of the other servomotors of the packaging machine 10. In order to counteract this, it is provided to enable the operator to turn the servomotor back into the synchronizing rotary position predetermined by the machine cycle or to recognize to the operator at which angle of rotation the synchronizing rotary position is reached.

The synchronous rotation corresponds in the example of Fig. 3-8 a rotation angle of 135 °. According to the invention, to deposit the synchronous rotary position in the second operating mode of the servo drive or, when the position control is switched off, as the desired rotary position. The control of the servo drive monitors the respective actual rotational position and, when the operator has rotated the shaft of the servo motor so far that the synchronous rotation position is reached, switches the position control automatically again: the servo drive changes from the second operating mode without position control to the first one Operating mode with position control.

In other words, the controller monitors the current operator-set rotational angle of the servomotor or servomotor shaft (or servomotor rotor). As soon as the actual rotational angle of the servo motor corresponds to the corresponding nominal rotational angle or the corresponding nominal synchronization rotational position, the position control of the motor is reactivated.

Similarly, the initial commissioning or maintenance of a machine can be significantly facilitated. It can be stored for each servo drive corresponding target synchronous loops, which would have to be set in order to operate the respective drives synchronously to the machine cycle or to the other drives can. The drives could initially be switched off in the context of the initial setup / maintenance and it would initially be activated in particular no position control.

An operator can then change the rotational positions of the servo drives by hand until the stored target synchronous rotations are reached. Then the servo drives are automatically transferred to the position control. A further twisting would not be possible due to the position control.

LIST OF REFERENCE NUMBERS

10

packaging machine

11

pack

12

outer wrapper

13

folding

14

Heft organ

15

conveyor line

16

promoter

17

Stapling and shrinking station

18

processing station

19

vertical conveyor

20

conveyor line

21

Sealing and shrinking station

22

Transfer station

23

treatment station

24

end conveyor

25

discharge conveyor

26

promoter

27

component

28

handwheel

Claims (12)

1. Method for the safe operation of a packaging machine (10) for producing packs for smokable products - such as, for instance, cigarettes - wherein the packaging machine (10) comprises at least one servo drive for driving at least one movable member, wherein, in the case of an initial commissioning of the machine (10) or after a machine stoppage, the servo drive is able to be operated in one of at least two operating modes, namely a first operating mode, in which position control of the servo motor is effected in such a manner that the respective actual rotary position of the servo motor is compared with a required rotary position and, in the case of deviations between the actual and the required rotary position, the actual rotary position is adapted to the required rotary position, and a second operating mode in which no position control of the servo motor is effected at least within a range of the angle of rotation, wherein

   a) the servo drive is automatically transferred from the first into the second operating mode when - whilst the servo drive is situated in the first operating mode - a torque, in particular a minimum torque of a predetermined size, is applied to the shaft of the servo motor of the servo drive by an operator, or wherein

   b) the servo drive is automatically transferred from the second into the first operating mode when, as a result of rotations effected by an operator, in particular by means of a mechanical or electronic hand wheel (28) which is coupled with the shaft, the shaft of the servo motor of the servo drive is moved into a predetermined required rotary position.
2. Method according to Claim 1, characterised in that the required rotary position, where the transfer into the first operating mode is effected, corresponds to a predetermined synchronous rotary position where synchronicity of the servo motor shaft is provided with at least one other servo motor shaft of another servo drive of the packaging machine, in a preferred manner with all other servo drives of the packaging machine, or with the machine clock.
3. Method according to one or several of the preceding claims, characterised in that after a machine stoppage of the packaging machine, the servo drive or all the servo drives is/are first of all transferred into the first operating mode or is/are situated in said operating mode.
4. Method according to one or several of the preceding claims, characterised in that, whilst the servo drive is situated in the first operating mode, the comparison between the required and the actual rotary position of the servo motor shaft and, where applicable, the necessary adaptation of the actual rotary position to the required rotary position, is effected continuously or at several or many discrete time intervals.
5. Method according to one or several of the preceding claims, characterised in that the servo motor is switched off in the second operating mode in which the servo drive is operated without position control.
6. Method according to one or several of the preceding claims, characterised in that the servo motor or all the servo motors are automatically stopped in a targeted manner in the event of a fault in the packaging machine, and in that the respective standstill rotary position is the respective required rotary position of the position control in the first operating mode.
7. Method according to one or several of the preceding claims, characterised in that the applying of the minimum torque is detected by way of a current increase which occurs in this case in an operating current of the servo drive.
8. Method according to one or several of the preceding claims, characterised in that the minimum torque of predetermined size is filed as a value in a storage unit, in that the torque applied onto the shaft by the operator is determined and compared with the minimum torque value filed in the storage unit, and in that the servo drive, in the case where the applied torque corresponds to the minimum torque value filed in the storage unit, is transferred from the first into the second operating mode.
9. Method according to one or several of the preceding claims, characterised in that the predetermined required rotary position is filed as a value in a storage unit, in that the rotary position set by the operator as a result of rotations is determined and compared with the filed required rotary position, and in that the servo drive, in the case where the set rotary position corresponds to the required rotary position filed in the storage unit, is automatically transferred from the second into the first operating mode.
10. Method according to one or several of the preceding claims, characterised in that in the second operating mode in which no position control is effected, the shaft of the servo motor is freely movable, in particular over a - where applicable predetermined - (part) range of the angle of rotation which is smaller than 360 degrees or over the entire range of the angle of rotation of 360 degrees.
11. Packaging machine for producing packs for smokable products, such as, for instance, cigarettes, said packaging machine having at least one servo drive for driving at least one movable member of the packing machine (10), and having a control device which is realised in such a manner that, in the case of an initial commissioning of the machine or after a machine stoppage, the servo drive is able to be operated in at least two operating modes, namely a first operating mode, where position control of the servo motor is effected in such a manner that the respective actual rotary position of the servo motor is compared with a required rotary position and, in the case of deviations between the actual and the required rotary position, the actual rotary position is adapted to the required rotary position, and a second operating mode in which no position control of the servo motor is effected at least within a range of the angle of rotation, wherein

    a) the servo drive is automatically transferable from the first into a second operating mode by - whilst the servo drive is situated in the first operating mode - a torque, in particular a minimum torque of a predetermined size, being applied to the shaft of the servo motor of the servo drive by an operator, or wherein

    b) the servo drive is automatically transferable from the second into the first operating mode by the shaft of the servo motor of the servo drive being set into rotation by the operator, in particular by means of a mechanical or electronic hand wheel which is coupled with the shaft, until the shaft reaches a predetermined required rotary position.
12. Packaging machine according to Claim 11, wherein the control device is realised in such a manner that it is able to implement one or several measures of Claims 1 - 10.

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