RU2433074C2 - Method of filling container with piece goods - Google Patents

Abstract

FIELD: transport.

SUBSTANCE: proposed method comprises feeding piece goods by at least one conveyor to two grippers located abreast in conveying direction to place said piece goods on free placing positions transferred on at least one conveyor for containers. On detecting reduction in or termination of feed, control over grippers is carried out in operating conditions that differ from common conditions.

EFFECT: higher efficiency of container filling.

13 cl, 5 dwg

Description

The present invention relates to a method for loading containers in pieces according to the restrictive part of claim 1.

State of the art

Piece goods supplied by conveyors from production plants to the packaging site can be fully automated by means of robots placed in the containers provided. EP 0250470 describes such robots, also called grippers or delta robots, for use on packaging lines. We are talking about a robot with a main body, to which by means of three levers consisting of two parts, a working body is pivotally attached, on which, in turn, grippers or suction cups are placed. From the publications US 6543987 and US 6896473 known improvements delta robot, in which it is equipped with a fourth axis of variable length. Instead of delta robots, you can also use other gripping and stacking robots, for example, so-called SCARA robots (with two or more horizontal arm joints) or six-axis robots.

Typically, piece goods and containers are transported on two or more parallel conveyors, and grippers, when continuously or cyclically moving the conveyors individually or in groups, capture the piece goods and place them in containers.

EP 0749902 A describes an installation in which piece goods are transported co-directionally, i.e. parallel and in one direction. EP 0 865 465 A discloses a counter-current installation, i.e. conveyors with containers and conveyors with piece goods, although they move in parallel, but in opposite directions of transportation.

In the publication EP 1285851 A, a method is proposed that allows to increase the service life or the maximum period of operation of gripping robots installed along similar sorting lines operating on the principle of uniform flow or counterflow. To do this, control robots is carried out depending on the location of piece products on the feed conveyor so that they are loaded in time as evenly as possible without strong fluctuations in their performance.

According to publication EP 1352831 A, the relative feed rate of containers and piece goods is regulated in the sorting line zone. In this case, the regulation of the relative speed is carried out depending on the filling level of at least one storage element. This method allows you to efficiently reload piece goods in containers at the most complete load.

However, all these methods are designed for normal operation of the installation. Always proceed from the fact that piece goods are served in sufficient quantities, and their shortage is eliminated as quickly as possible. At the end of the production cycle, for example, when changing products or their sizes, as well as when cleaning the unit or if the unit for the production of piece products unexpectedly fails, there will be too few piece products on the feed conveyor to fully load all containers already installed on the conveyor for containers. Typically, the problem is that by the time the production process stops, the number of products on the piece conveyor does not match the number of stacking positions or places in the container still to be filled. In particular, when working on the principle of counterflow, when, in addition, piece goods and containers to be filled "diverge" in different directions, many containers are already partially filled. In this case, reloading of partially filled containers is no longer possible.

Disclosure of invention

Therefore, the object of the invention is to propose a method which, at the end of the production cycle or with a shortage of piece goods, or with other interruptions in production, would allow to distribute piece pieces still remaining on the supply conveyor into containers or stacking positions in a fully automated and optimized way.

This problem is solved in the method characterized by the characteristics of paragraph 1 of the claims.

In the implementation of the proposed invention, the method of loading piece goods into stacking positions, especially containers or containers having a certain capacity for piece goods, piece goods are fed on at least one conveyor for piece goods to at least two grippers located one after another in the conveying direction devices, by means of these gripping devices, to place piece goods in the empty places of the stacking positions fed on at least one conveyor for containers s, primarily on empty seats in containers. When reducing or stopping the supply of piece goods, the operation of the gripping devices is controlled according to an algorithm that is changed compared to the usual mode of operation, or a loading strategy that excludes or minimizes the output of partially filled stacking positions, especially containers. In other words, the grippers operate in such a way that completely loaded and completely free stacking positions, especially containers, but in no case partially filled stacking positions, primarily containers, exit the installation.

In one embodiment of the invention, the at least one gripper device located ahead in the direction of conveyance of the container conveyor loads predominantly high fill containers. Completely empty containers are predominantly no longer loaded.

This makes it possible in the shortest possible time to form from the piece goods still on the conveyor for piece goods as many as possible fully loaded containers and to pack as many pieces as possible. It is taken into account that the conveyor for containers among the filled containers also transports individual empty containers for further processing. These empty containers can be removed from further processing without removing or overloading piece goods.

As an alternative or addition to the above option, at least one gripper device located behind in the direction of conveyance of the container conveyor can advantageously transfer piece goods from one partially filled container to another partially filled container. Moreover, when deciding whether to take piece goods from the first container or reload the first container with piece goods, it is preferable to take into account the number of piece goods in this first container and the total number of piece goods in other containers that are simultaneously in the working area of at least one gripping device, located behind in the direction of transportation of the conveyor for containers. Usually, if in other containers the piece is enough to fully load the first container, fill the first container. In the event that piece goods in other containers are not enough to fully load the first container, piece goods are taken from the first container. The first container is preferably a container located in the working area of each gripper head in the direction of transportation of the container conveyor, i.e. the container that first leaves the conveyor for containers.

Tests have shown that it is possible to work the conveyor for piece cargo idle for several minutes, in particular for 10 minutes. Manual reloading of containers is not required. There are almost no piece goods left on the conveyor for piece goods. In the ideal case, there are fewer of them than is necessary to fully load one container. For the final complete release of the conveyor for piece goods, time is practically not expended.

It is preferable to feed at full or reduced speed. At the same time, it is possible to work with full speed of transportation, with increased speed or with continuously decreasing speed.

Other preferred embodiments of the method of the invention are disclosed in the dependent claims.

Brief Description of the Drawings

Below the essence of the invention is illustrated by the example of a preferred variant of its implementation with reference to the accompanying drawings, which show:

figure 1 is a schematic illustration of a part of a packaging installation with conveyors for containers and piece goods and several robots in normal operation according to the principle of counterflow in accordance with the prior art;

figure 2 - packaging installation, shown in figure 1, shortly after the end of the production cycle;

figure 3 - packaging installation, shown in figure 1, at a later point in time;

figure 4 - packaging installation, shown in figure 1, at the end of the packaging of all piece products;

figure 5 is a schematic representation of part of the proposed invention, the packaging installation with conveyors for containers and piece goods and several robots at the end of the production cycle, working on the principle of codirectional flows.

The implementation of the invention

Figure 1 schematically shows a packaging installation of a known type. It has one or more conveyors 2 for containers intended for the supply of containers B, and one or more conveyors 1 for piece goods, intended for the supply of piece products S, which are preferably at least in separate sections parallel to each other and to the horizontal plane.

Conveyors 1, 2 preferably represent, in the case of transporting piece goods, or individual items, endless closed conveyor belts, and in the case of transporting containers, endless closed drive (gripping) chains. However, other known types of conveyors can be used. In this example, there is one horizontal conveyor 1 for piece goods and two horizontal conveyors 2 for containers. The conveyors 2 for containers are located on both sides of the conveyor 1 for piece goods, preferably in the same plane as the conveyor 1 for piece goods. The directions of transportation or supply for individual conveyors 1, 2 are shown by large, bold arrows. In this example, the installation works according to the counterflow principle.

Separate gripping devices R1-R8 are arranged along the transport path one after another. The gripping devices are preferably gripping robots, in particular delta robots of the type indicated at the beginning of the description, which can individually capture piece products and put them in containers. However, other gripping and handling devices can be used if they are capable of performing the required movements described below.

Preferably, the gripping elements of the gripping devices can freely move within the area of two-, preferably three-dimensional, space. Depending on the type of packaged piece goods, gripping devices can also be used that take the piece products in groups and place them in containers.

The number of robots used depends on the required plant performance and is not significant for the implementation of the invention.

Only their minimum number, which is equal to two, is limited. Depending on the location and number of conveyors, the grippers R1-R8 are also distributed differently. For example, they can be located on one side of the transportation path. They can also be installed in a row on two opposite sides of the transport path, in which case neighboring opposing devices can be located directly opposite each other or be offset relative to each other. In this example, four robots are installed on each side: on the first side along the first conveyor 2 for containers - robots R1-R4 and on the second side along the second conveyor 2 for containers - robots R5-R8. The individual robots are essentially identical. The working area K of each robot is shown as a circle. Circles K can overlap each other or be at a distance from each other.

Robots R1-R8 are interconnected via a central control device RS. The drawings show data lines only between robots R1-R4 and the control device RS. Of course, the rest of the R5-R8 robots are also connected to the central control unit. Robots R1-R8, additionally or instead of an individual communication line with a control device, can also be connected directly to each other.

If robots are used, then usually they receive from the central control device only information regarding the fill level of individual containers and the location of piece goods on the conveyor 1 for piece goods. The decision about which piece product this or that robot should capture next and in which container to put, is made by the local robot control device itself. However, this decision is confirmed by the central control device RS in order to inform other robots in this way. In order to ensure the exchange of this information with as little computational resources as possible, which means as quickly as possible, the entire production line and containers are preferably divided into one or more matrices or vectors in terms of queues, with each possible position occupying a place in the matrix or stored in vectors. By processing images, positions are recorded, i.e. x and y coordinates of all pieces. The strategy or algorithm by which the robot decides which of the piece products in the working area it should capture is based essentially on the queue formed according to certain criteria (for example, the distance from individual products to the virtual line in the working area). It does not matter whether the piece goods are transported by the piece conveyor in an orderly or random manner. The fact is that the position of real piece goods at the initial or inlet end of the piece conveyor is optically recorded and transmitted to the central control device RS. It is possible, but not necessary, to also optically re-register the filling level of containers at predetermined positions during their transportation and inform the central control device RS about this. Other methods for detecting and recognizing products and controlling robots are also possible.

In normal operation, the scheme of which is shown in figure 1, the conveyor 1 for piece cargo loaded with a sufficient number of piece goods, which allows you to load all containers In completely. A variety of strategies or algorithms can be used for downloading. Preferably, the algorithm described in publication EP 1285851 is used. In addition, in countercurrent mode, those robots in which the round working zone K contains a very large number of piece products, i.e. which are located at the beginning of the piece conveyor, mainly purposefully place products in the unfilled spaces of already partially filled containers. The same robots that are already receiving a weak stream of piece goods, i.e. which are located at the end of the piece conveyor, mostly just try, as far as possible, to load each container evenly. In all cases, the degree of filling of individual containers B during transportation in the loading area is continuously increasing. Thus, in normal operation, the highest efficiency and productivity of the packaging unit is achieved. At the same time, only piece goods from the conveyor for piece goods or, in any case, from the drive of piece goods, are always placed in containers. Within a group of containers or between containers, the movement of piece goods in normal operation does not occur.

If the flow of piece goods or products stops (is interrupted) or decreases sharply, this detects an optical recognition device at the inlet end of the feed conveyor or a central control device RS. If the flow of piece goods after a predetermined time has not already increased, the central control device RS is transferred to the loading strategy of the invention. The aim of the new loading strategy is to eliminate or minimize the exit from the installation of partially filled containers. Such a change in strategy can also be carried out directly by individual robots if they receive a message within a predetermined time to reduce the number of pieces or if the number of incoming pieces within a predetermined time becomes less than the minimum value. In this case, the minimum value for individual robots may be the same or different.

If later on the piece conveyor to the packaging section again more pieces arrive, the central control unit or individual robots will automatically switch to normal operation.

Proposed in the invention, the loading strategy for the almost complete release of the conveyor belt for piece cargo is as follows. The speed of the conveyor for piece goods and the conveyor for containers is reduced, for example, up to 60% compared with the speed in normal mode. Robots installed behind in the feed direction of the conveyor change their loading strategy in such a way as to now predominantly load almost full containers. That is, in essence, they do what the robots located in front of the conveyor feed direction did in normal operation, but unlike them, they ignore empty containers and no longer try to load them. As a reminder, in normal operation, robots located behind the conveyor feed direction must fill the least filled containers predominantly in order to achieve the most uniformly increasing degree of filling of the containers and, therefore, the conveyor conveyor speed as constant as possible. Now, with a changed strategy, the most recent at the beginning of the conveyor or several of the latest robots installed at the beginning of the conveyor begin to load piece goods from one container into another container. This overload process is shown in FIGS. 2 and 3 by small arrows. Thus, essentially only fully loaded or completely empty containers exit the loading area, as can be seen in FIG.

In a preferred embodiment of the method, at least one robot transferring piece goods from one container to another counts or takes into account the number of piece products in the frontmost container and the total number of all piece products in subsequent containers located in its working area K. If in subsequent there is enough piece goods in the containers to fill the very front container, it is filled by reloading the piece goods from the subsequent containers into the very front container ep. If there is too little piece goods, then, if possible, all piece goods are taken from the front container and loaded into subsequent containers. If a piece of product can be used from a piece conveyor to fully load a container, piece pieces are additionally, but not preferably, removed from the piece conveyor. If there are too many piece goods in the containers to completely empty or load the containers located in the working area K of the last or last robots, then these excess piece goods are returned to the piece conveyor to be re-captured at the end of the conveyor.

Robots installed between the last robot in the direction of conveyor feed and the first robot at the beginning of the conveyor during unloading, preferably depending on the piece goods still available on the conveyor for piece goods, switch from the last robot loading strategy to the first robot loading strategy. That is, first they fill the containers, and finally, when there is almost no piece goods left on the piece conveyor, they overload the piece goods in containers. At the same time, they can change the download strategy at the same time or one after another.

During unloading, all robots or at least the first robots at the beginning of the conveyor can also return piece goods from already partially filled containers to the piece conveyor.

This unloading process takes only a few minutes to empty the piece conveyor as completely as possible and release the fully loaded or completely empty containers from the container conveyor.

Proposed in the invention method is illustrated by the example of the installation, working on the principle of countercurrent. However, this method can also be applied to an installation operating on the principle of uniform flow, as shown in FIG. In this case, the robots installed at the beginning of the conveyor will primarily prefer fully loaded containers and add individual piece products to them. Robots installed behind the conveyor will in this case almost exclusively carry out the transfer of piece goods from partially filled containers to other containers. When working on the principle of uniform flow, the likelihood that robots installed behind the conveyor will leave at least one product on the conveyor for piece goods is very small. The robots in the middle of the conveyor will first adopt the strategy of the first robots at the beginning of the conveyor, and then the last robots behind the conveyor, depending on how many piece products will still be delivered to them.

If we compare the above-described unloading strategies of the installation when working on the principle of counterflow and on the principle of uniform flow, it becomes obvious that in both cases in containers that are the first to leave the conveyor for containers in the direction of its movement, i.e. in the last containers behind the conveyor, reloading is performed and the containers last arrive at the installation, i.e. the first containers at the beginning of the conveyor in the direction of movement of the container conveyor are loaded as fully as possible or left empty.

Various process options are possible. So, when working on the counterflow principle, the same conveyor can be used both for piece goods and for containers. Piece products in this case can be re-sorted or grouped on the same conveyor belt. Instead of containers, trays or working bodies of the conveyor chain or other stacking positions can also be loaded onto the conveyor. Piece products do not need to be stacked next to each other, they can be stacked on top of each other. Thus, if in the text or in the claims we are talking about containers, this concept always implies and also includes other types of certain stacking positions.

In one embodiment of the method, the number of piece goods remaining on the conveyor for piece cargo is controlled, and if this number is lower than the required number for the container to be fully loaded, the piece products are no longer captured, but are output under control, for example, at the end of the piece conveyor. Therefore, they do not need to be manually removed from the container.

Claims (16)

1. The method of loading piece goods (S) of stacking positions having a certain capacity for piece goods, in which piece goods (S) are fed on at least one conveyor (1) for piece goods to at least two consecutive in the transport direction to the grippers (R1-R8) and by means of these grippers (R1-R8) piece goods are placed on the empty places of the stacking positions supplied on at least one conveyor (2) for the container, and upon detection of contraction or pre ascheniya feeding piece goods work grippers controlled by altered compared to the conventional mode of operation loading strategy that excludes or minimizes the yield of partially filled packing position. 2. The method according to claim 1, in which when working on a modified loading strategy, at least one gripper device located in front in the direction of conveyance of the conveyor for containers loads predominantly stacking positions with a high level of filling, but predominantly does not load completely empty positions. 3. The method according to claim 1 or 2, in which at least one gripping device, located behind in the direction of transportation of the conveyor for containers, mainly loads piece goods from one partially filled position to another partially filled position. 4. The method according to claim 3, in which when deciding whether it is necessary to select piece goods from the first stacking position or to load the first stacking position with piece goods, the number of piece goods in this first stacking position and the total number of piece products in other stacking positions, which are simultaneously are located in the working area of at least one gripping device located behind in the direction of transportation of the container conveyor. 5. The method according to claim 4, in which if, at other stacking positions, the piece is enough to fully load the first stacking position, fill the first stacking position, and if the piece at other stacking positions is not enough to fully load the first position stacking, piece products are selected from the first stacking position. 6. The method according to claim 4 or 5, in which the first stacking position is a stacking position located in the working area of each gripper head in the direction of transportation of the container conveyor. 7. The method according to claim 3, in which at least one gripping device, located behind in the direction of transportation of the conveyor for containers, puts at the stacking position piece goods supplied by the conveyor for piece goods. 8. The method according to claim 3, in which the grippers located between the closure and the head in the direction of conveyor conveyor for containers with grippers depending on the piece products still available on the conveyor for piece goods, are transferred from the loading strategy of the first gripping device to the loading strategy last gripper. 9. The method according to claim 1, in which the piece goods from the already partially filled stacking positions are laid back on the conveyor for piece goods. 10. The method according to claim 1, in which the conveyor for piece cargo and the conveyor for containers are set in motion with full or reduced speed. 11. The method according to claim 1, in which the direction of transportation of at least one conveyor for piece goods in parallel, but opposite to the direction of transportation of at least one conveyor for containers. 12. The method according to claim 1, in which the direction of transportation of at least one conveyor for piece goods parallel to the direction of transportation of at least one conveyor for containers and is directed to it. 13. The method according to claim 1, in which as at least one conveyor for piece cargo using a horizontal belt conveyor. 14. The method according to one of claims 1, 2, 4, 5, 7-13, wherein the stacking positions are containers. 15. The method according to claim 3, in which the stacking position are containers. 16. The method of claim 6, wherein the stacking positions are containers.

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