Method and apparatus for automatically unloading packages for automatic order picking

Abstract

The invention relates to a method for automatically unloading packages for automatic order picking, wherein a plurality of packages are provided lying on a tray upstream of further processing, an unloading device is used to unload all the packages from the tray there and packages that are not required for subsequent further processing are loaded back onto a tray by means of a loading device such that only required packages are provided, and to a corresponding apparatus.

Description

[0001] Method and device for automatically unloading packages for automatic order picking

[0002] The invention relates to a method and a device for automatically unloading packages according to claim 1 and 11 respectively.

[0003] In today's distribution logistics, picking is becoming increasingly demanding. Therefore, it is necessary to develop picking systems that process orders automatically without manual intervention.

[0004] Thousands of different products (or packages) of varying characteristics (size, shape, weight, dimensions, surfaces, strength, compressibility, etc.) must be automatically picked using such systems. To handle these diverse packaging units uniformly, it is common practice to use trays for their storage and transport.

[0005] The automatic stacking of packages onto a base or carrier, especially a pallet or trolley, to form a stack for later shipping—in other words, "palletizing"—is a well-known process. This involves placing individual packages of uniform size or dimensions into predetermined locations by robots, grippers, etc.

[0006] The process of automatically loading a load carrier with packages of different characteristics to form a stack is known as automatic “mixed-case” palletizing.

[0007] EP 1 462 394 B1 discloses a device for automatically loading a load carrier with packing units forming a loading stack, i.e., a palletizing device. In this device, a packing unit lying on a table is pushed along the broad side of the pallet to be loaded by a pusher until the loading coordinates in the X direction are reached. Subsequently, another pusher and a loading tongue simultaneously push the packing unit in the direction of the loading depth over the pallet until the loading coordinates in the Z direction are reached. The loading tongue then retracts, with the pusher remaining stationary and acting as a scraper, so that the packing unit is deposited on the pallet at the desired location in a "free-falling" manner. The resulting stack is supported by a loading aid on the remaining three sides. Thus, it is essentially stacked "against the wall."However, moving the packing table is time-consuming and, due to limited accessibility, has disadvantages when forming the packing pattern. Furthermore, it is essential that the loading tongue and the stripper / pusher move simultaneously in the X-direction. Furthermore, only one packing unit can be "processed" sequentially at a time.

[0008] In the system or device according to EP 1 462 394 B1, the different articles or packaging units are stored individually on trays for better and simplified handling and then fed to the palletizing machine. The trays are unloaded in the palletizing machine itself, and the packaging units are ultimately palletized individually. Thus, this device can only handle individually loaded trays.

[0009] While loading trays individually offers handling advantages, especially with automatic tray unloading, it results in poor space utilization throughout the system. A correspondingly large number of trays is also required, which increases the cost and effort required for the feed line and thus limits the throughput of the palletizing system.

[0010] There are known systems in which multiple packing units are stored and moved per tray. For example, the companies Knapp (at 2:30 in https: / / voutu.be / UR8HXvvM6CA) and Vanderlande (at 2:10 in https: / / youtu.be / FwaqVpkDKtQ) demonstrate the targeted unloading of individual, desired packing units from a multiply loaded tray. Targeted unloading is time-consuming and complex, as the position of the packing units on the tray and relative to each other must be defined and known, and the pusher must be controlled accordingly.

[0011] It can be seen that the automated further processing of packages usually requires the packages to be made available without a tray, i.e. unloaded, and possibly separated.

[0012] In contrast, the object of the present invention is to provide a method and a device for automatically unloading packages for automatic order picking, which allow a flexible, targeted provision of packages from multiply loaded trays. This object is achieved by the method recited in claim 1 and the device according to claim 11. Advantageous embodiments emerge from the

[0013] Subclaims and the description.

[0014] According to the invention, it has been recognized that if all packages are first unloaded from a multiply loaded tray and then the unneeded packages are reloaded onto a tray, it becomes possible to more flexibly combine the advantages of multiple loading with those of individual palletizing. Thus, the method according to the invention is more tolerant with regard to the location and position as well as the alignment of the packages relative to each other on the tray, as well as with regard to the position of the tray relative to the stripper, since all packages are unloaded and thus become manageable (and, if necessary, alignable).

[0015] In other words, according to the invention, only the packages required for picking are not reloaded onto a tray, but are made available to the downstream palletizer.

[0016] Reloading takes place locally in the same device, making it relatively compact. Instead of first being stored and then retrieved, or distributed via long conveyor systems and processed elsewhere in the picking system, the packages are loaded directly into the device. This constitutes a module for the provision of the packages required for picking.

[0017] Preferably, the same tray is used for reloading. In principle, a different tray or even a different transport device could also be used. This can be done at the same location or separately, e.g., slightly downstream, especially if, for example, an alignment unit is provided between the unloading device and the loading device.

[0018] To simplify the reloading of unneeded packages and, if necessary, simultaneously separate the required packages (ungrouping or aligning), the required packages can be separated from the packages not required for subsequent palletizing by creating gaps in an alignment unit before reloading. This gap creation can be achieved using gapping methods similar to sorter technology.

[0019] The required packages can therefore be separated by creating gaps for subsequent processing, e.g. palletizing.

[0020] Trays typically have a rectangular surface and can therefore be transported with either the short or long side facing forward. Loading and unloading is simplified if the trays are aligned in front of the unloading device so that their short side is facing forward in the direction of transport. This allows unloading and loading to be carried out via the longer, broad side.

[0021] Safe and easy unloading can be achieved, for example, by lateral transfer, e.g., by pushing, onto a parallel track. For this purpose, trays can be unloaded from a tray feed line onto a parallel discharge track using the unloading device.

[0022] For this purpose, it is preferable if the surface of the discharge track in the unloading and reloading areas is at a similar height to the surface of the tray feed line. In particular, a lifted package should be level with its base on the discharge track to ensure smooth unloading and reloading.

[0023] An increase in throughput can be achieved if trays are alternately unloaded from two parallel tray feed lines onto a discharge track using the unloading device.

[0024] It is also possible to load and unload simultaneously on two tray feed lines.

[0025] One potential source of error is eliminated if the loading pattern of the packages when loading the trays upstream of the unloading device is selected so that the row of packages is stabilized by the tray edges. If necessary, the packages can be aligned in a row. This improves joint handling during unloading, e.g. by pushing them sideways without the packages becoming jammed. It is preferable if the packages are aligned along the edge of the respective tray. Alternatively, an error routine can be used if jamming occurs because a scraper pushes a package that in turn pushes another, resulting in jamming, wedging, etc. Such an error routine can include reversing the conveyors, changing the conveyor speeds, etc., in order to still create gaps.

[0026] A device according to the invention of a picking system for unloading trays loaded with packages and for reloading trays, in which several packages are provided lying upstream on a tray, comprises a first supply conveyor, a discharge track running at least partially parallel thereto, and an unloading device, wherein trays to be unloaded are delivered on the first supply conveyor. By means of the unloading device, all packages are transferred from the tray lying on the supply conveyor to the discharge track.Packages not required for subsequent (downstream) processing are returned from the discharge conveyor to a tray in an internal loading device (i.e. located in the same device), so that only packages required for picking remain on the discharge conveyor and are made available for subsequent processing by means of the discharge conveyor for picking.

[0027] Since both the unloading device and the loading device are spatially close to each other because they are positioned in the same device, the device is also compact.

[0028] Such a device is particularly suitable for the automatic provision of packages for multi-layer stacking of a carrier with packages in a subsequent palletizing process.

[0029] Corresponding trays have a frame with a raised, all-round edge and a base with at least one recess. Thus, by means of a lifting device, all packages can be lifted from below through the at least one recess to a level above the edge and the discharge track, allowing the unloading device to unload the packages onto the discharge track using a (unloading) pusher. While alternatives are conceivable, such as robot-assisted gripping, etc., these are considerably more complex and expensive, and usually require more complex control technology, given the very wide range of packaging types and shapes.

[0030] Preferably, the device comprises a loading device for transferring the unused packages from the discharge conveyor to a tray on the first supply conveyor. This can be configured similarly to the unloading device. A pusher or reloading pusher can also be used for this purpose.

[0031] Both the (unloading) pusher and the (reloading) pusher can be suspended on guides mounted above the supply conveyor or discharge track. Both are preferably located at the same location and share a discharge track, which can also be used for alignment (gap formation) if necessary.

[0032] An increase in throughput can be achieved if trays are unloaded alternately from two parallel tray feed lines onto a discharge track using the unloading device. For this purpose, the unloading device can have two corresponding (unloading) pushers.

[0033] It is also possible to load and unload simultaneously on two tray feed lines.

[0034] In a preferred embodiment, the device's discharge path comprises a sensor-controlled multi-zone conveyor arrangement, by means of which the required packages can be separated from the unneeded packages and also singulated. The conveyor arrangement can, for example, comprise roller conveyor zones arranged one behind the other, which are separately driven and controlled. A photocell arrangement capable of detecting the beginning and end of a package is sufficient as a sensor. This allows the detection of packages passing through.

[0035] The sensor-controlled multi-zone conveyor arrangement of the discharge track preferably comprises several consecutive conveyor zones, with the package sensor being arranged in the region of a second conveyor zone, which is shorter than a first and third conveyor zone and accelerates one or more packages in a controlled manner to separate them (form gaps). This acceleration can be carried out via a control system using the package sensor, so that the required packages are separated from the unneeded ones by targeted acceleration. The loading device can then immediately load the unneeded packages from the discharge track back onto one or the same tray.

[0036] If the device has two tray feed lines running parallel in the area of ​​the unloading device, which enclose the take-off track between them, wherein the unloading device comprises a respective unloading device assigned to the tray feed line and the take-off track comprises a loading device acting on both sides, the throughput of the device can be increased by parallelized processes.

[0037] Further details of the invention emerge from the following description of embodiments with reference to the drawing, in which

[0038] Fig. 1 - 4 each show a schematic plan view of a first embodiment of the invention in different phases of unloading and reloading, respectively;

[0039] Fig. 5 - 10 each show a schematic plan view of a second embodiment of the invention in different phases of unloading or reloading and

[0040] Fig. 11 shows perspective views of a tray in the transport position and the loading or unloading position.

[0041] Figures 1 to 4 show a first embodiment of a device 1 for unloading trays T loaded with a plurality of packages P for automatically providing packages P for multi-layer stacking (order picking) of a carrier (e.g. pallet or trolley) with the packages downstream in the conveying direction F.

[0042] The device 1 comprises a first supply conveyor 2, a withdrawal track 3 running at least partially parallel thereto, a discharge device 4 and a loading device 5. In addition, a photocell as a package sensor 6 and a control system 7 are provided for the device.

[0043] The first supply conveyor 2 is a roller conveyor with a conveying direction F. It is supplied with the loaded trays from a storage facility (not shown). Optionally, a device for aligning the trays T so that their short side is at the front in the transport direction F can be arranged upstream. Also upstream can be an optional device for aligning the multiple packages P in a row at the edge of the tray.

[0044] The trays T are known to have a frame R1 with a raised, circumferential edge R2 and a base B with at least one recess. Packages P lying on the base are lifted from below through the at least one recess to a level above the edge R2 by means of a lifting device (not shown) (see Figure 11), so that the unloading device 4 can unload the packages P onto the discharge track 3 in the transfer area 8.

[0045] The surface of the discharge track 3 in the transfer area 8 (the unloading and reloading area) is arranged at the same height level as the surface of the raised floor B.

[0046] The unloading device 4 is designed as a controlled pusher or unloading slider, which pushes all packages P laterally from the tray P onto the discharge track 3 in the transfer area 8 (Figure 2).

[0047] The discharge track 3 is designed in the transfer area 8 as a sensor-controlled multi-zone conveyor arrangement so that required packages P are separated from the unnecessary packages.

[0048] For this purpose, the sensor-controlled multi-zone conveyor arrangement of the withdrawal track 3 comprises three successive conveying zones 8a, 8b, 8c, wherein the package sensor 6 is arranged in the region of a second conveying zone 8b, which is shorter than a first and third conveying zone 8a, 8c and accelerates one or more packages in a controlled manner for separation.

[0049] The second conveyor zone has a higher speed than the first conveyor zone, so that the acceleration separates the respective package entering the zone from the other packages and thus enables the formation of gaps (Figure 3).

[0050] The conveyor system consists of roller conveyor zones arranged one behind the other, each of which is separately driven and controlled. A photocell array that can detect the beginning and end of a package is sufficient as package sensor 6. This allows the detection of packages passing through.

[0051] Thus, all packages P are transferred from the tray T on the supply conveyor 2 to the discharge track 3 by means of the unloading device 4.

[0052] Packages not required for subsequent processing are returned to a tray by the discharge track 3 (see Figure 4), so that only required packages remain on the discharge track and are made available for subsequent palletizing or picking by means of the discharge track 3.

[0053] For this purpose, the loading device 5 of the device 1 is also designed as a controlled pusher or reloading pusher S, which pushes all unused packages P laterally from the transfer area 8 of the discharge track 3 back onto the same tray T (Figures 3 and 4). The bottom B of the tray T is lowered again, so that only the edge R2 needs to be overcome (see above). The loading device 5 and unloading device 4 are thus spatially close and not separate.

[0054] Figures 5 - 10 show an expanded variant which differs from the previously described embodiment in that two tray feed sections 2A, B are provided which run parallel in the area of ​​the unloading device 4 and enclose the take-off path 3 there between them, wherein the unloading device 4 comprises a respective unloading device 4A, B assigned to the tray feed section 2A, B and the take-off path 3 comprises a loading device 5 acting on both sides, so that the throughput of the device can be increased by parallelized processes.

[0055] This means that a tray can be unloaded on one tray feed line and a tray can be reloaded on the other tray feed line at the same time.

[0056] In the present example, the tray T is first unloaded on the tray feed line 2A, whereby the loading device 5 is pre-positioned (Figure 6).

[0057] Subsequently, as above, the required packages P are formed or separated from those not required (Figure 7) and reloaded by means of the loading device 5 onto the same tray T on the tray feed line 2A (Figure 8).

[0058] Simultaneously, the tray is unloaded from the other tray feed line 2B by means of the unloading device 4B (Figure 8).

[0059] Then the gap formation takes place again (Figure 9) and simultaneous reloading or unloading (Figure 10).

[0060] It can be seen how the loading device 5 alternately reloads the packages P to the tray feed line 2A or 2B.

[0061] In this case, the package sensor 6 is located above so that it does not get in the way.

[0062] Figure 11 shows a tray T with frame R1, with a surrounding raised edge R2 and base B loaded with two packages P, in a transport position with base B not raised (Figure 11A) and an unloading position with base B raised (Figure 11B).

Claims

Patent claims 1. A method for automatically unloading packages for automatic picking, in which a plurality of packages are provided lying on a tray upstream of a further processing step, all packages are unloaded from the tray by means of an unloading device and packages not required for subsequent further processing are reloaded onto a tray by means of a loading device so that only packages required for picking are provided, wherein the unloading device and loading device are arranged in the same device.

2. Method according to claim 1, characterized in that the same tray is used for reloading.

3. Method according to claim 1 or 2, characterized in that the required packages are separated by gap formation from the packages not required for subsequent processing before they are reloaded.

4. Method according to one of the preceding claims, characterized in that the trays are aligned in front of the unloading device such that their short side is at the front in the transport direction.

5. Method according to one of the preceding claims, characterized in that trays are unloaded from a tray feed line by means of the unloading device onto a parallel withdrawal track.

6. Method according to claim 5, characterized in that the surface of the withdrawal path in the unloading area and in the reloading area is at a similar height level to the surface of the tray feed section, in particular at the level of a raised package.

7. Method according to one of the preceding claims, characterized in that trays are unloaded alternately from two parallel tray feed lines onto a take-off track by means of the unloading device.

8. Method according to one of the preceding claims, characterized in that loading and unloading takes place simultaneously at two tray feed lines.

9. Method according to one of the preceding claims, characterized in that the required packages are separated by forming gaps for subsequent palletizing.

10. Method according to one of the preceding claims, characterized in that the loading pattern of the packages when loading the trays upstream of the unloading device is selected such that the row of packages is stabilized by the tray edges and / or the plurality of packages are aligned in a row upstream of the unloading device.

11. Device of a picking system for unloading trays loaded with packages and for reloading trays, in which a plurality of packages are provided lying upstream on a tray, the device comprising a first supply conveyor, a withdrawal track running at least partially parallel thereto and an unloading device, wherein trays to be unloaded are delivered on the first supply conveyor, all packages are transferred from the tray on the supply conveyor to the withdrawal track by means of the unloading device and packages not required for subsequent further processing are returned from the withdrawal track to a tray in an internal loading device, so that only required packages remain on the withdrawal track and are provided for subsequent further processing by means of the withdrawal track for picking.

12. Device according to claim 11, characterized in that the trays comprise a frame with a circumferential raised edge and a base with at least one recess, and by means of a lifting device all packages are lifted from below through the at least one recess to a level above the Edges and raised to the level of the withdrawal track so that the unloading device can unload the packages onto the withdrawal track using an unloading pusher. Device according to one of the preceding claims 11 or 12, characterized in that the required packages are both separated from the unnecessary packages and singulated by means of a sensor-controlled multi-zone conveyor arrangement of the withdrawal track. Device according to claim 13, characterized in that the sensor-controlled multi-zone conveyor arrangement of the withdrawal track comprises several successive conveyor zones, wherein a package sensor is arranged in the region of a second conveyor zone which is shorter than a first and third, in particular up to a fifth, conveyor zone and in each case accelerates one or more packages in a controlled manner for separation.Device according to one of the preceding claims 11 to 14, characterized in that two tray feed sections are provided which run parallel in the region of the unloading device and enclose the withdrawal path there between them, wherein the unloading device comprises a respective unloading device assigned to the tray feed section and the withdrawal path comprises a loading device acting on both sides.

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