PACKAGING LINE OF A PACKAGING INSTALLATION AND METHOD FOR OPERATING SUCH A PACKAGING LINE

Abstract

A method for operating a packaging line of a packaging installation, wherein the packaging line includes at least one packaging machine having an infeed conveyor belt, wherein the packaging line further includes at least one transport belt which is disposed upstream of the infeed conveyor belt, wherein the method includes the steps of: i) defining and/or determining a current machine performance of the at least one packaging machine; ii) determining an output request for the at least one transport belt; and iii) defining and setting a transport speed of the at least one transport belt, wherein the transport speed is defined as a function of the determined output request.

Claims

1. A method for operating a packaging line of a packaging installation, wherein the packaging line comprises at least one packaging machine having an infeed conveyor belt, wherein the packaging line further comprises at least one transport belt which, viewed in the a transport direction of the packaging line, is disposed upstream of the infeed conveyor belt of the at least one packaging machine and in series with the infeed conveyor belt of the at least one packaging machine, wherein the method comprises the following method steps: i) defining and/or determining a current machine performance of the at least one packaging machine, wherein the current machine performance defines the number of products to be processed by the at least one packaging machine per unit of time; ii) determining an output request for the at least one transport belt, wherein the output request defines a number of products to be delivered to the infeed conveyor belt of the at least one packaging machine by the at least one transport belt per unit of time; and iii) defining and setting a transport speed of the at least one transport belt, wherein the transport speed is defined as a function of the determined output request.

2. The method according to claim 1, wherein the method further comprises the method step of determining a current fill level of the infeed conveyor belt of the at least one packaging machine, and wherein the transport speed of the at least one transport belt is defined as a function of the determined fill level of the infeed conveyor belt.

3. The method according to claim 1, wherein the transport speed of the at least one transport belt is calculated according to the formula: $V=R_{ne}\cdot \frac{l}{F{l}_{next}}$ with: V = transport speed R.sub.ne = output request from the infeed conveyor belt of the at least one packaging machine Fl.sub.next = fill level of the infeed conveyor belt of the at least one packaging machine with 0 ≤ Fl.sub.next ≤ 1 l = product length.

4. The method according to claim 1, wherein the transport speed of the at least one transport belt is defined such that, when products are transferred from the at least one transport belt to the infeed conveyor belt of the at least one packaging machine, pushing of the products on the infeed conveyor belt is prevented.

5. The method according to claim 1, wherein the packaging line comprises a total of n packaging machines connected in series, wherein n is a natural number greater than zero, and wherein a current machine performance of the at least one packaging machine is defined and/or determined as a function of a possible machine performance of each one of the total of n packaging machines.

6. The method according to claim 5, wherein the current machine performance of the at least one packaging machine is furthermore defined and/or determined as a function of a currently possible output of the at least one transport belt.

7. The method according to claim 1, wherein the packaging line comprises at least two packaging machines, which are connected in series and work together and each comprise an infeed conveyor belt and an outfeed conveyor belt, wherein the at least one transport belt is disposed between the outfeed conveyor belt of an upstream packaging machine and the infeed conveyor belt of a downstream packaging machine in series with the packaging machines, wherein the method comprises the following method steps: i) defining and/or determining a current machine performance of the downstream packaging machine, wherein the current machine performance defines the number of products to be processed by the downstream packaging machine per unit of time; and ii) determining an output request for the at least one transport belt, wherein the output request defines a number of products to be delivered to the infeed conveyor belt of the downstream packaging machine by means of the at least one transport belt per unit of time, wherein the defined and/or determined current machine performance of the downstream packaging machine and optionally a current fill level of the infeed conveyor belt of the downstream packaging machine are taken into consideration when determining the output request for the at least one transport belt.

8. The method according to claim 7, wherein the output request for the at least one transport belt is determined such that the number of products to be delivered to the infeed conveyor belt of the downstream packaging machine per unit of time by the at least one transport belt corresponds to the number of products to be delivered per unit of time which are to be processed by the downstream packaging machine in accordance with the current machine performance and which is necessary to achieve a previously defined or definable filling level of the infeed conveyor belt of the downstream packaging machine.

9. The method according to claim 7, wherein the method further comprises the following optional method step: iii) determining an output request for the outfeed conveyor belt of the upstream packaging machine, wherein the output request defines a number of products to be delivered to the at least one transport belt per unit of time by means of the outfeed conveyor belt of the upstream packaging machine, wherein the defined and/or determined current machine performance of the downstream packaging machine and a current fill level of the infeed conveyor belt of the downstream packaging machine, and optionally a current fill level of the at least one transport belt, are taken into consideration when determining the output request for the outfeed conveyor belt of the upstream packaging machine.

10. The method according to claim 9, wherein the output request for the outfeed conveyor belt of the upstream packaging machine is determined such that the number of products to be delivered to the at least one transport belt per unit of time by means of the outfeed conveyor belt of the upstream packaging machine corresponds to the number of products to be delivered per unit of time which are to be processed by the downstream packaging machine in accordance with the current machine performance and which is necessary to achieve a previously defined or definable fill level of the infeed conveyor belt of the downstream packaging machine and a previously defined or definable fill level of the at least one transport belt.

11. A packaging line of a packaging installation, wherein the packaging line comprises: at least one packaging machine having an infeed conveyor belt or at least two packaging machines, which are connected in series and work together and each comprise an infeed conveyor belt and an outfeed conveyor belt, wherein the packaging line further comprises at least one transport belt which, viewed in the a transport direction of the packaging line, is disposed upstream of the infeed conveyor belt of the at least one packaging machine and in series with the infeed conveyor belt of the at least one packaging machine, or which is disposed between the outfeed conveyor belt of a upstream packaging machine and the infeed conveyor belt of a downstream packaging machine in series with the packaging machines, wherein the packaging line further comprises a belt control system which is in particular constructed according to the principle of a pull system and is configured to communicate output requests and/or information from the infeed conveyor belt of the downstream packaging machine to the at least one transport belt and optionally from the at least one transport belt to the outfeed conveyor belt of the upstream packaging machine, via a bus system, in particular a Profibus system, counter to the transport direction of the packaging line as needed.

12. The packaging line according to claim 11, wherein the belt control system is configured to issue a first output request from the downstream packaging machine to the infeed conveyor belt assigned to the downstream packaging machine, wherein the first output request defines a number of products to be delivered to the downstream packaging machine by means of the infeed conveyor belt per unit of time, wherein the belt control system is further configured to issue a second output request from the infeed conveyor belt of the downstream packaging machine to the transport belt immediately upstream of the infeed conveyor belt, wherein the second output request defines a number of products to be delivered to the infeed conveyor belt of the downstream packaging machine by means of the immediately upstream transport belt per unit of time, wherein the belt control system is in particular further configured to issue a third output request from the transport belt immediately upstream of the infeed conveyor belt to a further transport belt immediately upstream of the transport belt or to the outfeed conveyor belt of the upstream packaging machine, wherein the third output request defines a number of products to be delivered to the transport belt immediately upstream of the infeed conveyor belt by means of the further transport belt or by means of the outfeed conveyor belt of the upstream packaging machine per unit of time.

13. The packaging line according to claim 12, wherein the first output request is determined by a current machine performance of the downstream packaging machine, wherein the current machine performance defines the number of products to be processed by the downstream packaging machine per unit of time; and/or wherein the second output request is determined by a current machine performance of the downstream packaging machine and by a current fill level of the infeed conveyor belt assigned to the downstream packaging machine; and/or wherein the third output request is determined by a current machine performance of the downstream packaging machine, by a current fill level of the infeed conveyor belt assigned to the downstream packaging machine and by a current fill level of the transport belt immediately upstream of the infeed conveyor belt.

14. The packaging line according to claim 11, wherein the at least one transport belt and the infeed conveyor belt of the downstream packaging machine and optionally the outfeed conveyor belt of the upstream packaging machine are each assigned a system for detecting a current fill level of the corresponding conveyor belt or transport belt, and wherein the belt control system is in particular configured to set a transport speed of the at least one transport belt as a function of the current fill level of a transport or conveyor belt, viewed in the transport direction of the packaging line, immediately downstream of the at least one transport belt, wherein the downstream transport or conveyor belt is the infeed conveyor belt of the downstream packaging machine, and wherein the current fill level of the downstream transport or conveyor belt is the current fill level of the downstream transport or conveyor belt at the time of an output request from the downstream transport or conveyor belt.

15. The packaging line according to claim 14, wherein each system for detecting a current fill level of the corresponding conveyor belt or transport belt has a light barrier system comprising a light barrier at the beginning of the belt and a light barrier at the end of the belt, wherein the light barriers at the respective beginnings of the belts are configured such that, when occupied by a product, said light barriers are released again when the corresponding conveyor or transport belt is in motion, and wherein the light barriers at the respective ends of the belts are mounted and/or configured such that, when occupied by a product, said light barriers are not released again when a corresponding downstream conveyor belt is in motion; and/or wherein the belt control system is configured to further set the transport speed of the at least one transport belt as a function of an output request from the transport and/or conveyor beltimmediately downstream of the at least one transport belt, wherein the transport speed is in particular the higher the greater the number of products to be delivered per unit of time defined by the output request and the smaller the fill level of the transport or conveyor belt immediately downstream of the at least one transport belt.

Description

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0066] FIG. 1 shows schematically, an example embodiment of the packaging line according to the invention in an overall view;

[0067] FIG. 2 shows schematically, three transport belts, which are connected in series and work together, of an example embodiment of the packaging line according to the invention; and

[0068] FIG. 3 shows schematically, three transport belts, which are connected in series and work together, of an example embodiment of the packaging line according to the invention to illustrate the detection of the fill level.

DETAILED DESCRIPTION OF THE INVENTION

[0069] A packaging line of the type considered here comprises packaging machines which are connected in series and work together. They perform tasks such as carton folding and carton unfolding, carton filling and finishing. Packaging lines can be expanded in a modular manner, for example with a case packer.

[0070] In the packaging line shown schematically in FIG. 1, for example, different packaging devices or packaging machines are provided one after the other (downstream), which in particular have different nominal outputs and set outputs. The nominal output determines the number of products/packs per unit of time that can be output by the respective packaging machine and can also be referred to as the nominal capacity. The set output determines the actual number of packs/products output per unit of time and can also be referred to as the current capacity. The number of packs/products that a packaging machine can accommodate per unit of time can also be referred to as the intake capacity. This is typically identical to the set output, in particular when the number of products introduced in the packaging machine is equal to the number of products output, which is the rule.

[0071] Since the packaging machines disposed one after the other in the packaging line in particular have different nominal outputs and set outputs, the intake capacity of the different packaging machines is usually also different.

[0072] As shown schematically in FIG. 1, a conveyor or transport belt, which is in particular part of the respective packaging machine, is provided before and after (i.e., viewed in the transport direction of the packaging line, upstream and downstream) of each individual packaging machine. An infeed conveyor belt is provided at the entrance of each packaging machine and an outfeed conveyor belt is provided at the exit of the packaging machine.

[0073] Since the packaging machines are disposed sequentially one behind the other in the packaging line, uninterrupted operation is necessary to prevent products from backing up on the respective transport or conveyor belts.

[0074] Product accumulation at the entrance of a packaging machine can be prevented by providing a clamp or a stopper in the region of the infeed conveyor belt that prevents further transport of products to the entrance of the packaging machine. Subsequent products then run onto the products stopped by the stopper and pile up. However, this procedure is problematic for soft packaging, because the products can be damaged when they come into contact with one another.

[0075] A belt control system (line controller) is therefore provided in the solution according to the invention shown in the drawings, which takes on the central management of the line-relevant data of the individual packaging machines and the other components of the packaging line, such as in particular the transport or conveyor belts in the packaging line. The essential control function of the belt control system is that each individual packaging machine and each individual transport or conveyor belt of the packaging line sends its possible output to the belt control system.

[0076] The belt control system in turn limits the output of all of the packaging machines in the packaging line to the slowest reported machine performance and the current possible output of the at least one transport belt provided between the packaging machines and serving as “storage”. This results in an output target for all of the packaging machines. Based on this output target, each packaging machine requests a calculated output from the feeding transport or conveyor belt.

[0077] In FIG. 1, the respective output requests from the components of the packaging line against the transport direction of the packaging line are indicated by the reference sign L and the corresponding arrows.

[0078] The output request for the transport or conveyor belts is based on the output request of the following belt and the current fill level of the own transport belt.

[0079] FIG. 3 schematically shows a corresponding fill level determination for the transport or conveyor belts of a packaging line. In the design example shown schematically in FIG. 3, the fill level determination for each transport or conveyor belt is carried out by means of two light barriers.

[0080] More specifically, as indicated schematically in FIG. 3, a first light barrier is provided at the beginning of the belt of the respective transport or conveyor belt and a further light barrier is provided at the end of the belt of the respective transport or conveyor belt.

[0081] The light barrier at the beginning of the belt is preferably mounted such that, when occupied by a product, said light barrier is released again when the corresponding transport or conveyor belt is in motion and the, viewed in the transport direction of the packaging line, upstream transport or conveyor belt is stationary or is moving more slowly. The light barrier at the end of the belt, on the other hand, is preferably mounted such that, when occupied by a product, said light barrier is not released again when the downstream transport belt is in motion.

[0082] In the example embodiment of the packaging line shown in the drawings, it is accordingly provided that each transport or conveyor belt determines the current fill level for itself. This is in particular calculated with the aid of the light barrier at the beginning of the belt, the transport belt speed and the transport belt length. The target fill level is an adjustable variable and can be set by an operator of the packaging line via an interface (for example on the panel).

[0083] The belt control system is constructed according to the principle of a pull system. This results in a flow of information against the transport direction of the packaging line. Consequently, an output request (number of products per unit time) always has to be submitted by a following belt or even a packaging machine. Conversely, this output request also has to be passed on to the upstream belt.

[0084] If, for example, in the system shown schematically in FIG. 2, the downstream belt requests 120 products per minute and the current fill level of the downstream belt corresponds to the previously defined or definable target fill level, a request of 120 products per minute is also submitted to the upstream belt.

[0085] If, on the other hand, the downstream belt requests 0 products per minute and the current fill level corresponds to the previously defined or definable target fill level (i.e., the fill level has been reached), a request of 0 products per minute is also submitted to the upstream belt and the upstream belt stops immediately.

[0086] However, if the downstream belt requests 0 products per minute and the current fill level of the downstream belt does not correspond to the target fill level (i.e., the fill level of the downstream belt has not been reached), a request is submitted to the upstream transport belt until the current fill level of the downstream belt corresponds to the previously defined or definable target fill level. The upstream belt then stops.

[0087] In the example embodiment of the packaging line according to the invention shown in FIG. 1, for example, it is accordingly provided that each packaging machine is able to communicate the needed number of products to the upstream transport or conveyor belt. This product request or output request consists of the current number of cycles (i.e., the current machine performance) of the packaging machine plus an offset. The offset can be positive as well as negative and directs the packaging machine to its respective output target.

[0088] The packaging machine should register the filling in the infeed area (i.e., the fill level of the infeed conveyor belt). As already mentioned, this can be carried out by the fill level determination on the infeed conveyor belt or also by evaluating a buffer behind the divider. The maximum number of cycles of the packaging machine is limited by the output target determined by the belt control system.

[0089] In order to quickly transport the products to the next packaging machine when the transport belts are empty, in the embodiment of the packaging line according to the invention shown schematically in the drawings, the speed of the transport belts is calculated as a function of the fill level of the downstream transport belt. The transport speed is in particular calculated such that pushing of the products at the transfer locations is prevented.

[0090] In the design example shown in FIG. 2, for example, the downstream transport belt requests the needed number of products from the front transport belt. The transport speed is calculated from this request and the fill level of the downstream transport belt as shown in the following equation:

[00003]$V=R_{ne}\cdot \frac{l}{F{l}_{next}}$

with: [0091] V = transport speed [0092] R.sub.ne = output request from the downstream transport or conveyor belt [0093] Fl.sub.next = fill level of the downstream transport or conveyor belt [0094] l = product length

[0095] The networking of the packaging line is preferably implemented using Profibus-DP. This means that all data relevant for production is transmitted between the belt control system and the multiple packaging rails via Profibus-DP.

[0096] The invention is not limited to the design examples shown in the drawings, but results when all of the features disclosed herein are considered together.