EP1990279B1 - Method for strapping goods to be packaged with a strapping machine - Google Patents

Description

Method for strapping a packaged product with a strapping machine comprising a motor drive with a drive shaft which rotates through 360 ° within a strapping cycle and thereby controls working components comprising at least one clamping device for the band to be strapped

Strapping machines of the type described are known and serve to pack a packaged goods, for example a catalog stack, with a plastic band, ie to span it. In this case, an existing plastic strapping band is guided around the packaged goods, stretched back, clamped and cut and welded by heating by means of a welding device, after which the strapped packaged goods are conveyed from the strapping machine and fed new packaged to umreifendes.

A strapping machine has a tape guide frame, in which the strapping is injected via a Einschießvorrichtung, and a tape guide in the area below the packaged in which the einzießende tape out as well as the leading end of the tape is caught. The strapping can be brought out of the tape guide frame and in direct contact with the packaged goods for retensioning. Further provided is a clamping device comprising two separate clamping jaws, one of which clamps the leading end of the tape and the other after retightening the other end of the tape, both adjacent to an overlapping region in which the welding takes place. Also provided is a welding device comprising a welding tongue, which is moved to heat the tape ends in the overlap region between them, as well as a pressing device and a counter-pressure plate, wherein the pressing device is moved from below against the counter-pressure plate, between them are the heated, to be welded tape ends. The control of the movable functional components via a drive motor or driven by this drive shaft, with which the various functional components are directly or indirectly coupled in motion. Frequently cam disk couplings are used, that is, on the drive shaft one or more cams are arranged on or on the corresponding driver sections of a functional component run and be moved in accordance with the cam profile accordingly.

During a strapping cycle, the drive shaft once turns 360 °. In known machines is in the basic position, ie at the beginning of a Umreifungszyklus, the new packaged goods already in the strapping machine, ie in the tape guide frame, the movable tape guide is in the retracted work position, so can lead the tape, the strapping itself is already shot into the tape guide frame and caught with its leading end. At this time, the drive motor is stationary, so the drive shaft does not turn. Then, in a first step, the engine is started, it begins the so-called flow. The motor drives to actuate the right jaw of the clamping device via the drive shaft so that it clamps the leading end of the tape. Once this is done, the motor brakes again and stops, since then first the Rückspannschritt takes place, that is, the strapping, which was of course shot with a much larger strip length than the Umreifungsbandlänge required, is fed back into the machine in a tape storage and while tightly clamped around the packaged goods. During this time, the motor or the drive shaft is because the Rückspannvorgang is performed by a separate Rückspanneinrichtung. Only then does the motor or drive shaft start again in order to operate in the next step the left jaw to clamp the band at the then cut other end, and to operate for welding the other functional components (in this case, the tape guide off the work area is moved, the welder is moved into the work area, after heating it is moved out again and the pressing device is moved against the pressure plate to perform the welding). After the welding is completed, the pressing device is moved back into the starting position while the engine drive is still running and the printing plate is moved out of the working area so that the now strapped packaged goods are released and the packaged goods change can take place. As soon as the strapped packaged goods have been removed, the counterpressure plate is again moved together with the tape guide to the working position, the motor stops, its working cycle is finished. Then follows only the shooting of the strapping for the next Umreifungsvorgang. However, the motor cycle is finished with the second stop, the motor or the drive shaft has once rotated 360 °. Then, the new motor cycle begins, namely when the motor turns again briefly to actuate the right jaw, and immediately stops again, since then the Rückspannvorgang begins as described above.

As can be seen in such known strapping a two-stop method is realized. The motor will start twice within one cycle and stop twice, with the first start in the run alone serving to actuate the right jaw to fix the leading end of the tape, after which the motor will stop to allow for back tensioning. This is disadvantageous not only for reasons of wear, but ultimately also increases the time required for Packgutumreifung, so that the machine throughput is thereby inevitably reduced.

The invention is therefore based on the problem to provide a method that allows a faster and less wear leading strapping.

To solve this problem, it is provided according to the invention in a method of the type mentioned above that the deadlock between the beginning of removal of the already in the current Umreifungszyklus already strapped in the current strapping cycle of the leading, in a tape guide frame tape end of the strapping tape Packaged goods and the end of the introduction of a newly packaged packaged goods, after which the drive stops and after completion of the Rückspannvorgangs the tape shot around the packaged to carry out the Umreifungsvorgangs continuously without stopping in the new Umreifungszyklus by 360 ° rotates until re-clamping of the leading new band end ,

In the method according to the invention the clamping of the leading end of the tape, so the operation of the right jaw in the time of Packgutwechsels is placed with particular advantage. Within a strapping cycle, based on the drive time of the motor, this or the drive operates continuously, it stops only once, namely at the end of the Umreifungszyklus or this is finished with the engine stop. In the normal position, ie at the beginning of a new Umreifungszyklus, the right jaw is already operated and closed, that is, the leading end is already clamped. After completion of the Packgutwechsels so, since the leading end of the tape is already clamped, can be started immediately with the re-clamping, after which, when the re-clamping is completed, the drive one time within the entire cycle anfährt to actuate the left jaw and then continuously continues to operate to operate the other functional components until the end of the drive cycle, when after the shooting and catching the leading end of the tape as the last motor-driven activity within the Umreifungszyklus the right jaw is guided into the clamping position. The engine then stops, the already started Packgutwechsel is still continued and terminated, after which, as soon as the new packaged goods in position can be started in the next Umreifungszyklus with the Rückspannen.

In the method according to the invention, the motor is therefore started and stopped only once within a cycle, otherwise it rotates continuously by 360 °. This is made possible after the end of the Umreifungszyklus, based on the driving activity, in the time of the current Packgutwechsels is set and the last drive-controlled action, the right clamping device is actuated, so that the basic position is taken in the leading end of the tape is already clamped , The engine is inevitably less stressed because it does not start and brake twice within a cycle, but only once, also a faster operation is possible because with the elimination of a drive and braking time savings. As a result, the machine throughput can be increased.

The removal of the strapped packaged goods preferably begins immediately after the drive shaft controlled via the outward movement of a tape welding pressure plate from the tape guide area and open clamping device, preferably in the remaining rotational angle interval of the drive shaft from 160 °, preferably from / to 200 °. From this angle of rotation, ie by 160 ° or z. B. 200 °, the counter-pressure plate, which is from the welding forth between the welded strip portion and the packaged, pulled out of this area, the packaged goods is released so that it can then be deducted immediately. In the remaining rotation angle interval between at least 160 ° (or for example 200 °) to 360 ° shaft rotation then sufficient time remains for the Packgutwechsel, which should still start as early as possible within this interval. The shooting of the new strapping then takes place, for example, from about 300 ° rotation, so that still sufficient angle of rotation remains to operate the right clamping device and to clamp the leading end of the tape, after which the rotation cycle is completed. The motor will stop, the new turning or strapping cycle will not start until it is re-started when the operation of the left jaw is required, then continue to run continuously until the end of the cycle. The large number of controlled activities of the functional elements thus takes place in the rotation angle interval between 0 ° to z. B. 160 ° or 200 ° instead, while over the remaining rotation angle interval is obtained sufficient time to perform the package change can.

Fig. 1

eine Prinzipdarstellung einer erfindungsgemäßen Umreifungsmaschine,

Fig. 2-6

Prinzipdarstellungen des Schweißkopfs der Umreifungsvorrichtung aus Fig. 1 in unterschiedlichen Arbeitssituationen während eines Umreifungszyklus,

Fig. 7

ein Ablaufschema des erfindungsgemäßen Verfahrens, und

Fig. 8

ein Ablaufschema eines Verfahrens nach dem Stand der Technik.

Further advantages, features and details of the invention will become apparent from the embodiment described below and with reference to the drawings. Showing:

Fig. 1

a schematic diagram of a strapping machine according to the invention,

Fig. 2-6

Schematic representations of the welding head of the strapping from Fig. 1 in different work situations during a strapping cycle,

Fig. 7

a flow chart of the method according to the invention, and

Fig. 8

a flowchart of a method according to the prior art.

Fig. 1 shows a strapping machine 1 according to the invention, wherein only essential components are shown here for reasons of clarity. Shown is a welding head 2, comprising a clamping device 3 with a right jaw 4 and a left jaw 5, which, as will be discussed below, serve to fix the band. Both are biased by a spring 6 and run over rollers 8, 9 on the outer surface of a pressing device 10 which is vertically movable. The outside of the pressing device 10 is provided in its lower part on both sides with a cam structure 11, which follow the rollers 8, 9, about which the movement, here pivoting of the jaws 4, 5 for pressing or releasing the tape takes place. The pressing device 10 itself is vertically movable as described. The control takes place via a drive 12, of which only the drive shaft 13 is shown here, which is coupled to a motor not shown in detail. On the drive shaft 13 more cams 14 are arranged, of which only one is shown here, which has a guide groove 15, in which an impeller 16 engages, which in turn is connected to the pressing device 10. According to the shape of the guide groove, the vertical movement is controlled upon rotation of the cam 14.

Shown is also a tape guide device 17, which has a central guide channel 18, in which the injected into a tape guide frame not shown here in detail tape is guided. Attacked is the tape guide device 17 by a counter-pressure plate 19, against which the pressing device 10 presses the fused tape sections during welding in order to connect them firmly. For melting is a welding device 23 comprising a Welding tongue 24 is provided, which is not shown here for reasons of clarity, but in the area between the pressing device 10 and counter-pressure plate 19 is retracted or is movable from this area. The functional components "belt guiding device 17, counter-pressure plate 19, welding tongue 24" can likewise be actuated in a corresponding manner via the drive 12, that is to say they are likewise suitably coupled with optionally one respective cam disk. The plurality of cams are arranged one behind the other on the drive shaft 13. The movement of the individual functional components is preferably carried out by pivoting the same, whereby two functional components can be coupled in motion, as shown by the example of the pressing device 10 and the two jaws 3, 4, which are moved over the vertical position of the pressing device 10 and thus the position of the curved sections 11 ,

A welding head, which is designed in the manner described, or a strapping machine is for example off DE 103 23 171 B4 known.

The general drive 12, and thus the movement of the functional components actuated over here, as well as the operation of further functional components such as the insertion device for feeding tape into a tape guide frame or the device for conveying and feeding the packaged goods, which are all not shown in detail here, is now designed in such a way that that within a Umreifungszyklus the motor or the drive 12 starts only once, rotates 360 ° and brakes again. The process of the invention is based on the Fig. 2-6 and 7 seen.

Fig. 2 shows as a partial section of the strapping machine 1, the welding head 2 in the normal position at the end of a Umreifungszyklus or at the beginning of a subsequent Umreifungszyklus. In this position, the strapping 20 was already injected via the Einschießeinrichtung not shown in the here also not shown tape guide frame, the leading end of the tape 21 was caught in the area between the platen 19 and the tape guide device 17. At the same time was about to turn Drive 12 of the right jaw 4 is actuated so that it has been brought into the clamping position, the clamping head 22 of the jaw 4 can be seen on the tape 20 and clamped against the counter-pressure plate 19. The left jaw 5, however, is still open. With the clamping of the band, so the pressing of the right jaw 4, the motor or drive cycle ends, that is, the drive 12 and the engine brakes and comes to a standstill. During the subsequent period of the change of the packaged goods, which was previously strapped, still terminated, that is, the shooting of the tape, the collection of the tape and as the last cycle operation, the clamping of the tape on the right jaw in the time interval in which the Packgutwechsel takes place, is laid. In Fig. 2 in the lower area - the same applies to the following figures 3 - 6 - is shown in each case the side view of the welding head of the upper diagram, in which case the welding device 23 is shown with the welding tongue 24, which is not arranged in this end and initial position in the work area.

After completion of the Packgutwechsels, ie when the newly packaged goods to be strapped was conveyed into the tape frame, the strapping is pulled out of the tape guide frame and fed back into the strapping machine, so therefore stretched to the new packaged about a also not shown in detail tape retractor. During this Rückspannschrittes the drive 12 is still resting, that is, it has not been operated since the end of the drive cycle with the operation of the right jaw 4. Only when the reverse voltage is completed, the drive 12 is actuated, the engine starts and begins its duty cycle, within which it rotates continuously without another stop by 360 °. In Fig. 3 If the situation has already been shown in which the back tension has already occurred, the strapping band can be seen to be much closer around the packaged product, which is not shown in detail here. At the same time, the left jaw 5, in the starting position according to Fig. 2 was still solved, in the clamping position, that is, the clamping head 27 also acts on the belt 20, so this is fixed in two places. The clamping jaw 5 was also actuated via its movement coupling to the pressing device 10, which was controlled via the rotating drive 12 or the rotating drive shaft 13 and the cam plate 14. Then, immediately after clamping over the left jaw 5, the tape guide device 17 moved out of the work area, as in Fig. 3 shown, then the welding device 23 pivots with its welding tongue 24 in the working area between the overlapping tape ends, namely the leading end of the tape 21 and the rear tape end 25, which is cut off via a suitable cutting edge 26 on the pressing device 10. The two band ends to be overlapped are melted over the welding tongue 24. These movements are all controlled by the drive 12, which continues to rotate.

Fig. 4 now shows the Verschweißstellung in which the welding device 23 together with welding tongue 24 after melting was driven out of the work area, whereas the pressing was started up and presses against the platen 19, the two belt ends 21, 25 while pressing against each other. This upward movement of the welding device 23 and the upward movement of the pressing device 10 via the continuously rotating drive 12th

After completion of the welding or pressing the counter-pressure plate 19 is pivoted out of the working area via the rotating drive 12, so that, see Fig. 5 , the packaged goods are released. Because during the welding according to Fig. 4 If the counterpressure plate is located between the welded strip and the packaged goods, this could not be removed in this position. Only after release by pivoting out of the counter-pressure plate 19, the Packgutwechsel can take place. At this time, of course, the two jaws 4, 5 are released, which also takes place via the drive 12 by appropriate positioning of the pressing device 10, with which the two jaws 4, 5 are coupled. That is, as soon as the counter-pressure plate has been moved out of the work area, the Packgutwechsel can take place. Nevertheless, the drive 12 still works, the drive shaft 13 is still rotating. Because immediately after removing the strapped packaged goods, the counter-pressure plate 19 as well as the belt guiding device 17 is brought into the working position via the drive 12, the pressing device 10 is moved down again, so that new strapping 20 in the tape guide frame can be injected, as in Fig. 6 shown. Once the tape is shot, the right jaw 4 is brought back into the clamping position on the still rotating drive 12, after which immediately stops the drive 12, his cycle is finished. The then assumed configuration or position of the functional components corresponds to the end position, but at the same time also the starting position according to Fig. 2 , The Umreifungszyklus ends with the drive stop, a new begins with the immediately following restraint of the strap 20 to the conveyed new packaged goods.

Fig. 7 shows a schematic representation of the process sequence according to the invention. The strapping cycle begins on the left, whereby here the strapping machine or the welding head in the basic position according to the Fig. 2 located. The curve shows the operation of the motor or drive, which is at a lowered curve and works at a raised curve, so turns. In the first, labeled A section, the return of the already inserted strapping band, which already, as with respect to Fig. 2-6 described, is clamped with its leading end over the right jaw 4. Only at the time t ₁ , the drive 12 or the motor goes on, whereupon, as indicated by B, first pressing the left jaw 5 for clamping the back-tensioned band at the other end followed, after which the welding tongue 24 is retracted as well the other functional components are actuated to finally drive the pressing device 10 against the counter-pressure plate 19 in order to press the molten strip ends. In the immediately following section marked C, as described, the counterpressure plate 19 is briefly moved out of the working area, after which the change of packaged goods begins at the time t ₂ , as shown by the section labeled D. At time t ₂ , the now already strapped packaged goods is released, it can be carried away. The section C is of very short duration, since the removal of the packaged goods takes place very quickly, immediately followed by the section D, in which the counter-pressure plate 19 is moved back to the working position. Of course, during the removal of the Paketguts, so in section C, the clamping device 3 is open, both Clamping jaws 4, 5 are thus pivoted into the non-clamping position, as well as possibly the pressing device 10 is shut down.

After the tape guiding device 17 has again moved into the working area during the section D, immediately following the method section D, in FIG Fig. 7 marked with E, the Einschießvorgang done while the tape shot into the tape guide frame and the leading end between tape guide means 17 and counter-pressure plate 19 is collected. After shooting takes place immediately in section F, the jamming of the leading end of the tape 21 via the right jaw 4, again controlled by the drive 12. Only then is the drive 12 and the motor off, in Fig. 7 at time t ₃ . As can be seen, the drive 12 rotates during the entire working interval from t ₁ -t ₃ , without making a single stop. What is essential for this is that the jamming of the leading strip section 21 according to method section F takes place at the end of the strapping cycle or during the period of the package change according to method section G. When the Packgutgutwechsel is completed in accordance with section G, the cycle begins again, that is, the process begins again in the diagram according to Fig. 7 left with the clamping of the inserted tape.

Obviously, a fast strapping, ie a high cycle, can be driven hereby, because the motor or drive is only to start up or drive up once in the cycle and to stop only once, in between the drive rotates continuously. Accordingly, the method according to the invention or a strapping cycle is faster at least by the time required for the first start, the right-side jamming and the first-time braking, which is in the range of slightly above one anyway in the already very short strapping cycles The second, including the package change, has a considerable impact. A reduction of the cycle time by 10 - 20% is possible. Another advantage is the inevitably given protection of the engine or the drive and all its components that are just started and stopped just once in a cycle, compared with the prior art. Furthermore, due to the unique, continuous drive run basically the Possibility to run the drive also at a lower speed, since the required setting or actuation operations can be controlled in slightly longer windows than in the prior art.

Fig. 8 shows for comparison only a corresponding process flow diagram, which represents the operation according to the prior art. Obviously done at the beginning, see Fig. 8 on the left, first the method step F, that is, the drive is started up, after which the actuation of a right band clamping is performed, after which the drive is braked immediately again. This is followed by the process section A (Rückspannen), at the end of the drive is raised again to perform the process sections B, C and D. At the end of the process section D, in which the pressure plate is moved forward again, the drive is stopped again. This is followed by the renewed Einschießvorgang, that is, the tape is injected while the engine or drive is. The Packgutwechsel begins at the end of the process section C, so if the counter-pressure plate has been moved out. Only when the Packgutgutwechsel is completed in accordance with Section E, and also when the tape was shot, a new cycle may begin, in accordance with Fig. 8 first the drive is started up again, etc.

Claims (2)

1. Method for strapping a packagable product using a strapping machine comprising a motor drive having a drive shaft which rotates about 360° within a strapping cycle and in so doing controls working components comprising at least one clamping device for the belt which is to be strapped, characterised in that the clamping of the leading belt end of the belt which is to form a strap in the subsequent strapping cycle, which belt end is fed into a belt guiding frame, occurs already in the current strapping cycle, in the time between the beginning of the removal of the packagable product which has already been strapped in the current strapping cycle and the completion of the introduction of a new packagable product which is to be strapped, whereupon the drive stops and, after the conclusion of the process of tensioning the fed-in belt around the packagable product in performance of the strapping process, rotates continuously about 360°, without an intermediate stop, in the new strapping cycle, until the leading new belt end has in turn been clamped.
2. Method according to claim 1, characterised in that the removal of the strapped packagable product preferably begins immediately after a pressure plate for welding the belt has been moved out of the belt guiding region, under the control of the drive shaft, and when the clamping device is open, preferably in the remaining rotational angle range from 160°, preferably from or up to 200°.

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