Device for transporting packaging materials, in particular bottles or cups

Abstract

Device for transporting packaging materials, comprising - at least one transport device (10), - at least one workstation (20, 22, 24, 26, 28), - at least one packaging carrier (14) which the transport device (10) moves along at least one work station (20, 22, 24, 26, 28), - at least one drive (16, 18) for driving the transport device (10), characterized in that - at least one further drive (16, 18) is provided for driving the transport device (10), wherein at least one of the two drives (16, 18) is controlled to set a desired tension of the transport device (10) for the further transport of the packaging carrier (14).

Description

State of the art

[0001] The present invention relates to a device for transporting packaging materials, in particular bottles or cups, according to the preamble of the independent claim.

[0002] A device of this type for transporting bottles or the like is known, for example, from DE 195 42 673 C2. The conveying device has an endless chain, with at least one stationary measuring device for the length of the chain arranged on the chain's orbit.

[0003] Furthermore, a chain conveyor, in particular a trough chain conveyor or a double strand chain conveyor, with a tensioning device for controlled pretensioning of at least one first and second conveyor chain of the chain conveyor, each circulating endlessly over several drive and / or deflection wheels, is already known from DE 20 2015 104 101 U1.

[0004] Furthermore, a conveyor, especially for chips for conveying away from machine tools, is already known from DE 10 2013 108 577 A1. The invention is based on the objective of further increasing the accuracy of the transport device. This objective is achieved by the features of the independent claim. Disclosure of the invention

[0005] In contrast, the device according to the invention for transporting packaging materials according to the features of claim 1 has the advantage that the wear and elongation of the chain or the transport system, which would lead to reduced chain tension, are detected and mitigated. This enables precise positioning of the packaging material carriers relative to the processing stations. Mispositions that could lead to collisions with other stations are avoided. Furthermore, the movement quality of the packaging material carriers is improved by reducing shocks and vibrations that would otherwise cause significant wear and tear. Manual readjustment between the modules and the chain is unnecessary, as this can be done automatically with the device according to the invention.

[0006] According to the invention, this is made possible by providing two drives for the transport device, wherein at least one of the drives is controlled in the sense of a desired tension of the transport device, in particular of an associated chain or belt.

[0007] In a suitable further development, it is provided that one of the drives is controlled as the master drive and the other drive is controlled as a slave drive, dependent on the control of the master drive. This allows for a particularly simple control system when using two drives to power only a single chain.

[0008] In a suitable further development, it is planned that the two drives are controlled synchronously with each other. This type of control is particularly easy to implement from a control engineering perspective, ensuring that the desired chain tension is achieved.

[0009] In a suitable further development, it is provided that at least one of the drives, in particular the slave drive, is controlled with a positional offset relative to the other drive, in particular the master drive. This allows for particularly precise compensation of the respective chain elongation in such a way that the desired chain tension can be maintained. The positional offset is particularly advantageously dependent on the desired chain tension and / or chain elongation.

[0010] This makes it particularly easy to set and influence the desired parameters.

[0011] In a suitable further development, at least one control system is provided which, upon a change in the torque applied by at least one of the two drives, modifies the control signal of at least one drive, in particular by changing the positional offset with which the drive is controlled. Wear, especially chain elongation, is particularly usefully determined by measuring changes in the torque that one of the drives, especially the slave drive, must apply. This value provides sufficient information about the current chain tension and is generally available to a drive anyway without the need for additional sensors.

[0012] In a further development, a sensor is provided to detect wear on the transport device, particularly on a chain as a component of the transport device. This sensor allows the condition of the transport device to be monitored either intermittently or continuously, and targeted countermeasures to be taken by appropriately controlling the drives. For this purpose, preferably at least one controller is provided which, depending on at least one output signal from the sensor, controls at least one of the two drives.

[0013] In a suitable further development, it is envisaged that the control system activates at least one workstation depending on the sensor's output signal. Since the detected state of the transport system affects the relative positioning of the packaging carrier to the workstation, misalignments of the workstations relative to the packaging carrier can be easily compensated for. This increases the safety of the arrangement.

[0014] In a suitable further development, the control system is designed to control the drives using a referencing mechanism, so that a reference position is reached within the area of ​​a reference station. This increases the accuracy between the packaging carrier and the workstations or this reference station, since the reference position serves as the starting point for all further determinations of chain elongation and its potential effects on the positioning of the packaging carriers at other workstations. Preferably, the reference station is also a workstation. Preferably, the workstations are a transfer station and / or a sealing station and / or a filling station and / or a packaging station and / or a testing station and / or a packer.

[0015] Further appropriate training courses result from other dependent requirements and the description. Brief description of the drawing

[0016] Preferred embodiments of the invention are described in detail below with reference to the accompanying drawing. The drawing shows: Fig. 1. A perspective view of the transport device as it passes through various workstations, Fig. 2 an enlarged view of the arrangement of the sensor at the end of the transport device, Fig. 3 An enlarged view of the sensor arrangement at the beginning of the transport device, Fig. 4 a perspective view of the transport device with three sensors as well as Fig. 5 a perspective view of the transport device with an alternative arrangement of two sensors. Description of the exemplary embodiment

[0017] The following refers to the Fig. 1, Fig. 2, Fig. 3, Fig. 4 to Fig. Section 5 describes a transport device 10 in detail. The transport device 10 is used for transporting packaging materials such as cups or bottles, particularly in filling plants for liquid or pasty food products. However, its use is not limited to this. The transport device 10 comprises at least one chain 12 or a belt. A plurality of carriers 13 are attached to the chain 12. These carriers 13 interact with packaging carriers 14 to be attached to them. The packaging carriers 14 have receptacles 15 in the form of circular recesses for receiving a packaging material (not shown). Several receptacles 15 can be provided per packaging carrier 14, so that several packaging materials can be transported and processed simultaneously, for example, filled and closed. Each of the two end faces of a packaging carrier 14 is connected to a chain 12.The packaging carriers 14 are moved along different stations 24, 26 or workstations via the chains 12.

[0018] The chain 12 is driven via at least one drive wheel 17, which is moved by a drive 16. A deflection 19 is provided on the other side of the transport device 10. The deflection 19 is also driven by another drive 18. Here, for example, teeth (not shown) engage with the chain 12.

[0019] A sensor 30 is arranged on the transport device 10, preferably at the beginning of the transport device 10. The sensor 30 is located, for example, in the area of ​​the transfer station 20. As will be shown in more detail later, the sensor 30 is arranged outside the chain 12 so that any elongation of the chain 12 can be reliably detected. Optionally, a further sensor 32 can be provided. This could, for example, be arranged at the other end of the transport device 10, as shown in the exemplary embodiment. In the exemplary embodiment, the further sensor 32 is located in the area of ​​the packer 28. However, it is also possible to arrange only a single sensor 30 on the transport device 10. Alternatively, only the further sensor 32 could be provided in the area of ​​the packer 28.

[0020] Sensor 30 sends a sensor signal 31 to a controller 34. The other sensor 32 sends another sensor signal 33 to the controller 34. The controller 34 may be used to control the drive 16 and / or the other drive 18. The controller 34 may also receive corresponding position signals from the drives 16 and 18, or other parameters of the drives 16 and 18, such as the applied torque, speed, or similar information. An operator interface 36 is connected to the controller 34. The user can send corresponding operating commands to the controller 34 via this interface 36. Furthermore, relevant information or warning messages can be output to the operator via the interface 36.The controller 34 can optionally be connected to the transfer station 20 and / or the further stations 24, 26 and / or the referencing station 22 and / or the packer 28, as examples of possible workstations, for controlling and / or providing feedback of relevant parameters. The term "controller 34" is by no means to be interpreted restrictively, but encompasses the control systems typical for servo drives with associated control loops, for example, regarding position, speed, torque, or similar parameters.

[0021] A transfer station 20 is provided at the beginning of the transport device 10. The packaging material can be fed to the respective packaging carrier 14 via this transfer station 20. The transfer station 20 is slidable along a transport direction 9 of the transport device 10 or the chain 12, preferably in a horizontal direction. The transfer station 20 extends over the entire packaging carrier 14, so that each of the receptacles 15 can be filled with packaging material.

[0022] A reference station 22 is arranged transversely to the transport direction 9 of the transport device 10, spanning the entire width of the transport device 10. The reference station 22 could, for example, be located in the center of the transport device 10. The reference station 22 is a specific workstation whose position serves as the reference position for the drives 16, 18. Particularly when using servomotor drives 16, 18, automatic referencing to the freely chosen zero point in the machine is possible.

[0023] Further stations 24 and 26 are connected; two workstations are shown as examples, but there can be fewer or more. These further stations 24 and 26, or even just individual workstations, can also be moved in the transport direction 9 of the transport device 10. This adjustability of stations 24 and 26, or workstations, can be used to adjust the positioning of stations 24 and 26 to any detected changes in the length of the chain 12. Possible stations 24 and 26, or workstations, include, for example, a sterilization module, a filling device, a sealing device for applying a lidding film to a filled packaging material, or similar components.Stations 24 and 26 can also be used for extracting foreign particles, applying snap-on lids, control systems (e.g., for cup tightness), or labeling systems (e.g., for marking or coding a lid). The packaging carriers 14 serve to transport the packaging material to the workstations 20, 22, 24, 26, and 28 required for each work step.

[0024] As its final station, the transport device 10 approaches a packer 28. This packer 28 can grip appropriately processed packaging materials (e.g., filled and sealed cups) and feed them into further processing steps. When the transport device 10 is integrated as part of a filling machine with a downstream packaging system, in which the packer 28 is used, the gripper system of the packer 28 is subject to increased demands. The packer 28 collects individual packages in a tray to form a multi-pack. Even slight deviations in positioning can lead to malfunctions in the packer 28 or damage to the packaging material. The sensor signal 33, which measures the positional deviation of two adjacent packaging carriers 14, namely the determined distance 40 relative to a target dimension, can be transmitted to the packer 28.The packer 28 can control a gripper's picking movement precisely to the center of the packaging carrier 14. This preferably occurs depending on the determined distance 40 or a deviation from the target dimension. Alternatively, sensor signals 33, 37 from further sensors 32, 35 could also be used. In this case, the elongations of the chain 12 determined by further sensors 32, 35 can be extrapolated to the position of the packer 28. It is assumed that the chain 12 has elongated uniformly. Based on the known distance between the respective sensor 32, 35 and the packer 28 or the other desired workstation 20, 22, 24, 26, the resulting elongation is extrapolated or interpolated. Using this determined elongation, the associated workstations 20, 22, 24, 26, 28 can be moved further in the transport direction 9 accordingly.

[0025] An excerpt from the Fig. 1 is now in the Fig. Figure 2 shows an enlarged view. The sensor 32 is positioned laterally to the chain 12 such that, in a specific position, it determines the distance 38 between two adjacent packaging carriers 14 along the transport direction 9. The sensor 32 is located at the end of the transport device 10 near the packer 28. The elongation of the chain 12 is determined based on the distance 38 between two adjacent packaging carriers 14. For this purpose, the sensor 32 is oriented with its detection range transversely to the transport direction 9 of the transport device 10. The detection range is preferably selected such that the distance 38 between two packaging carriers 14 can be reliably detected, both in the normal state and in the state of an elongated chain 12. The corresponding sensor signal 33 is sent to the control unit 34 for further evaluation. The sensor 32 thus serves to measure the offset of the chain links or packaging carriers 14 in the transport direction of the transport device 10.The sensor 30, 32 detects the current elongation of the chain 12 based on the determined distances 38, 40.

[0026] In the enlarged view according to Fig. Sensor 30 is located in the area of ​​the transfer station 20. Similar to sensor 32 at the packer 28, sensor 30 is oriented so that a distance 40 between two adjacent packaging carriers 40 can be reliably detected in the area of ​​the transfer station 20. A corresponding sensor signal 31 is forwarded to the controller 34. The other sensor 32 is stationary and located laterally to the moving chain 12. Its detection range is oriented so that it reliably detects the end faces of the packaging carriers 14 and their distance 40. Alternatively, sensor 30 could also be oriented so that it also detects the area between the carrier 13 and the packaging carrier 14, i.e., a distance perpendicular to the transport direction 9. This allows monitoring of the correct attachment of the packaging carrier 14 to the carrier 13.If the distance between the carrier 13 and the end face of the packaging carrier 14 is too large, perpendicular to the transport direction 9, a faulty fastening is assumed. This can be signaled to the user with a corresponding message at interface 36.

[0027] The order according to Fig. 4 differs from that of the Fig. 1. The feature is that a further sensor 35 is provided, so that a total of three sensors 30, 32, 35 are present. This (third) additional sensor 35 is also arranged laterally to the chain 12 in the area of ​​the reference station 22. The first sensor 30 is located at the beginning of the transport device 10 in the area of ​​the transfer station 20. The (second) sensor 32 is located at the end of the machine or transport device 10 on the packer 28. This measures the total elongation of the chain 12 from station 20 via station 22 to station 28. The additional sensor 35 sends a further sensor signal 37 to the controller 34.

[0028] The order according to Fig. 5 differs from that of the Fig. 4. The difference lies in the fact that sensor 32 is now missing in the area of ​​packer 28. Therefore, only two sensors are provided: sensor 35 in the area of ​​reference station 22 and sensor 30 in the area of ​​transfer station 20, each arranged laterally to the chain 12. The chain elongation at the end of the machine or transport device 10 at packer 28 is scaled linearly up over the distance from station 20 to station 22, and possibly to further workstations, such as packer 28.

[0029] The drive wheel 17, which serves to propel the chain 12, is driven by the drive 16, preferably a servo motor, particularly with a gearbox. The deflection wheel or deflection 19 is also moved by a further drive 18, which likewise acts to propel the chain 12. This further drive 18 can also preferably be a servo motor, particularly with a gearbox. The drives 16 and 18 operate in a mode in which the chain 12 is tensioned without play in an upper chain run during movement and standstill and is subjected to the lowest possible preload defined by the drives 16 and 18. For this purpose, at least one of the two drives 16 and 18 is controlled to set a desired tension of the transport device 10, in particular of the chain 12 and / or a belt of the transport device 10.In this context, tension refers in particular to a mechanical load exerted on the transport device 10, especially on the chain 12. The drives 16, 18 are moved to positions in which the chain 12 is preferably tensioned without backlash. For a backlash-free tension of the chain 12, the position of the drives 16, 18 depends on the increasing elongation of the chain 12 over time. Thus, at least one of the drives 16, 18 is moved to a position relative to the other drive 16, 18 in response to any elongation of the chain 12, in which this elongation is compensated for. This can, for example, correspond to the increase in elongation.Alternatively, at least one of the drives 16, 18 could be activated and moved while the other drive 16, 18, which exerts a holding torque on the chain 12, is stationary, until a significant increase in torque is required to achieve the next position increment. This increase in torque indicates that the chain 12 is now sufficiently tensioned. The drives 16, 18 can then be activated synchronously for the normal transport of the packaging carrier 14, as described below, so that the desired tension of the chain 12, for example in the form of the desired length of the chain 12 between the two drive wheels 17, 19, is maintained.

[0030] Thanks to the preferably servo-motor-driven drives 16, 18, automatic referencing to a freely selectable zero point in the machine is possible. The drives 16, 18 can be set in a freely selectable ratio to distribute the pulling and pushing loads. For example, the pulling load is assigned a ratio of 50–90% of the total load, and the pushing load a ratio of 10–50% of the total load. The design of the drives 16, 18, including the size-determining drive 16, 18, can typically be one standard size smaller than with individual drives. The maximum load of the chain 12 of the packaging carrier 14 is higher than with individual drives.

[0031] The drives 16 and 18 preferably operate in a master-slave configuration with a tensioning function between drive 16 and drive 18. This ensures that the chain 12 is kept constant and smooth, without backlash. The drive system is referenced to a defined zero point. During production, the system can be held at the center of the station (the respective station 24 or 26). Alternative reference points can be defined in the transport chain 12, which can be activated as needed.

[0032] The pulling drive 16, 18 is the master, the pushing drive 18, 16 the slave. In the exemplary embodiment, with the transport direction 9 shown, drive 18 would be the pulling drive, i.e., the master, and drive 16 at the beginning of the transport device 10 would be the slave. There are different ways to operate the drives 16, 18. In a first variant, the control technology is simpler. Here, the slave drive 18, 16 follows the master drive 16, 18 synchronously. For this purpose, the controller 34 sends corresponding setpoint speed values ​​to the two drives 16, 18.

[0033] In another variant, both drives 16, 18 follow the motion profile of a virtual axis. The slave drive 18, 16 operates with a position offset (input, e.g., 2 mm). The position offset causes a slight lag, resulting in tension on the chain 12. As the chain 12 gradually stretches during operation, the drive torque of the slave drive 18, 16 decreases. The controller 34 of the slave drive 18, 16 detects this decreasing torque. The controller 34 increases the offset value to maintain a constant torque of the slave drive 18, 16 and thus a constant tension on the chain 12.

[0034] The return of the chain 12 or the upper run, which is not explicitly shown in the figures, can be tension-free. There are different variations. For example, the chain 12 can be laid down during the return run. Alternatively, a chain 12 with tensioning wheels could be provided during the return run. Furthermore, a drive wheel 17 or a deflection 19 with a tensioning function in the transport direction 9 would be possible.

[0035] The machine length, or the length of the transport device 10, is known. Therefore, the target dimension (theoretical dimension) of the machine or transport device 10 from station 20 to station 28 is known. The machine and the modules or stations 20, 22, 24, 26, 28 mounted on it have a displacement range of approximately half the width of the packaging carrier 14 (e.g., 50 mm). When the chain stretches by approximately 0.5%, the limit of the adjustment range of a module or station 20, 22, 24, 26, 28 is reached. After this, a chain 12 must be replaced with a new one. Using sensors 30, 32, and 35 to measure chain elongation and machine operating times, predictions for maintenance and adjustment of the machine are possible, for example, a prediction of the time until the next readjustment of modules or stations 20, 22, 24, 26, and 28, or the time for chain replacement. This information is output via interface 36.For each machine station (stations 20, 22, 24, 26, 28), the actual position of chain 12 can be calculated. The offset between the actual value and the target value yields the current difference. The controller 34 and the interface 36 inform the operator whether the machine is operating within a safe operating range or whether the workstation (stations 20, 22, 24, 26, 28) or the module needs to be readjusted. Readjustments can be performed fully automatically or manually. For this purpose, the controller 34 could send corresponding signals to the (work) stations 20, 22, 24, 26, 28 to, for example, slightly adjust the position according to the current elongation of chain 12.

[0036] The sensor 30, 32, 35 for the positioning accuracy of the packaging carrier 14 or the chain 12 can receive a signal in the vertical direction in addition to a signal in the transport direction 9 (chain elongation measurement function). Packaging carrier 14 that has become detached from the carrier 13 of the chain 12 (for example, due to loosened screw connections) is thus detected when the distance between the packaging carrier 14 and the carrier 13 exceeds a permissible dimension. The interface 36 alerts the operator to the need for troubleshooting. The packaging carrier 14 can be automatically moved to a repair position.

[0037] Alternatively, the sensor(s) 30, 32, 35 could be arranged above or below the packaging carriers 14, preferably laterally, to detect the gap between two adjacent packaging carriers 14 from above or below. Alternatively, a bore or countersink in the packaging carrier 14 or a pin on the packaging carrier 14 could also be detected. Detecting a roller of the chain 12 during a measurement from below also provides information about the condition of the chain 12. Thus, the sensor 30, 32, 35, which is equipped with a certain level of intelligence, can directly output a signal corresponding to an analog value of the chain elongation. Furthermore, the sensor 30, 32, 35 could directly output an alarm signal if the chain 12 is worn. This would occur if the current chain elongation exceeds a permissible limit.

[0038] In filling machines where the transport device 10 is preferably used, workstations such as stations 20, 22, 24, 26, and 28 with high positioning accuracy are particularly important. These include, for example, stations 24 and 26 for the extraction of foreign particles, snap-on lids, cup leak testing, and lid marking or coding.

[0039] These machines, along with their associated transport devices, are primarily used in the dairy industry and for filling liquid to pasty foods, including baby and hospital food. Increasingly, these filling machines are also being used for soft drinks, soups, and sauces.

Claims

[1] Device for transporting packaging materials, comprising - at least one transport device (10), - at least one workstation (20, 22, 24, 26, 28), - at least one packaging carrier (14) which the transport device (10) moves along at least one work station (20, 22, 24, 26, 28), - at least one drive (16, 18) for driving the transport device (10), characterized by , that - at least one further drive (16, 18) is provided for driving the transport device (10), wherein at least one of the two drives (16, 18) is controlled to set a desired tension of the transport device (10) for the further transport of the packaging carrier (14). [2] Device according to claim 1, characterized by , that at least one of the two drives (16,18) is controlled depending on a detected wear of the transport device (10). [3] Device according to any one of the preceding claims, characterized by , that with changing wear, the control of at least one of the two drives (16,18) changes. [4] Device according to any one of the preceding claims, characterized by , that one of the drives (16,18) is controlled as a master drive and the other drive (16,18) is controlled as a slave drive depending on a control of the master drive. [5] Device according to any one of the preceding claims, characterized by , that the two drives (16,18) are controlled synchronously with each other. [6] Device according to any one of the preceding claims, characterized by , that at least one of the drives (16,18) is controlled with a position offset relative to the other drive (16,18). [7] Device according to any one of the preceding claims, characterized by, that the positional offset depends on the desired tension of a chain (12) of the transport device (10) and / or an elongation of the chain (12) of the transport device (10). [8] Device according to any one of the preceding claims, characterized by , that at least one control (34) is provided which, when a torque supplied by at least one of the two drives (16,18) changes, changes the control of at least one drive (16,18). [9] Device according to any one of the preceding claims, characterized by , that at least one control (36) is provided which determines wear based on a change in a torque which one of the drives (16,18) must apply. [10] Device according to any one of the preceding claims, characterized by, that at least one control (34) is provided which controls the drives (16,18) in a referencing operation, so that a reference position in the area of ​​a reference station (22) is reached. [11] Device according to any one of the preceding claims, characterized by , that at least one sensor (30, 32, 35) is provided for recording a dimension (38, 40) for detecting wear of the transport device (10). [12] Device according to claim 11, characterized by , that at least one control (34) is provided which, depending on at least one output signal (31, 33, 37) of the sensor (30, 32, 35), controls at least one of the two drives (16, 18). [13] Device according to claim 11 or 12, characterized by , that at least one controller (34) is provided which controls at least one workstation (20, 22, 24, 26, 28) depending on the output signal (31, 33, 37) of the sensor (30, 32, 35). [14] Device according to claim 4, characterized by , that the slave drive is driven with a reduced torque compared to the torque with which the master drive is driven. [15] Device according to any one of the preceding claims, characterized by , that the workstation (20, 22, 24, 26, 28) is at least a transfer station and / or a sealing station and / or a filling station and / or a packaging station and / or a testing station and / or a packer.

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