Method for operating a tank treatment plant

Abstract

Method for position matching between a gripper (3) of a changeover robot of a container treatment system, in particular a blow molding machine, and a treatment part to be gripped, wherein in an initialization process the gripper (3) of the changeover robot (2) is successively moved to a storage position of a plurality of treatment parts (1) and the position coordinates of the storage positions are stored in a control device (8) and wherein subsequently in a changeover process the changeover robot (2) moves the gripper (3) to at least one storage position on the basis of the position coordinates.

Description

[0001] The present invention relates to a method for position matching between a gripper of a changeover robot of a container treatment system, in particular a blow molding machine, and a treatment part to be gripped.

[0002] Such container treatment systems are generally known from the prior art, with the invention preferably relating to blow molding machines, in particular for the production of beverage containers. These beverage containers can be, for example, beverage bottles made of a thermoplastic material, in particular polyethylene terephthalate (PET).

[0003] For blow molding, preforms are typically prepared and heated in a heating device. Heating softens the material of the preforms, making them easier to deform when exposed to a fluid. The actual forming process then takes place in the blow molding machine. The blow molding machine has at least one mold, which forms a cavity with a contour that corresponds to the shape of the container or beverage bottle to be produced.

[0004] Accordingly, the blow mold determines both the size and shape of the containers to be produced, and a changeover is necessary if different types of containers are to be manufactured. The blow mold change is usually accomplished by removing the blow molds of a first set from the blow molding machine and placing them in a storage unit. Blow molds of a second set can then be taken from this or another storage unit and inserted into the blow molding machine. The changeover can, in principle, be performed manually. However, it is now also common to automate the changeover using changeover robots.

[0005] Such a design is disclosed, for example, in DE 10 2017 120 774 A1 and EP 2 878 425 B1. In this design, the changing robot, equipped with a gripper, automatically moves to and grips the blow molds in the storage unit or the blow molding machine to effect a change of the blow molds within the blow molding machine. Similar systems are also known from DE 20 2019 102 226 U1, DE 10 2014 103 159 A1, and DE 20 2012 013 536 U1.

[0006] For such an automated changeover, it is therefore necessary that the changing robot knows the individual position coordinates of storage locations, e.g., in the storage system, so that it can easily grip the blow molds during the changeover process. In this context, a storage location refers to a position that the changing robot must move its gripper to in order to grasp the blow mold.

[0007] In principle, the stock positions of the blow molds are predetermined, for example, by the design of the storage system. However, practical experience has shown that the individual stock positions can deviate slightly from their target positions, requiring the changeover robot to be moved to these differing position coordinates. In practice, this is usually achieved by adjusting the position coordinates in the control device until the exact stock position is reached. This process is time-consuming and impractical, especially with a large number of blow molds.

[0008] Although blow molding machines are used as an example, this problem also arises with other container treatment systems, which are accordingly equipped with other treatment parts instead of blow molds.

[0009] The invention is based on the objective of providing a method and a device that simplifies and optimizes the setup of a container treatment plant.

[0010] The invention relates to a method according to claim 1, a container treatment system according to claim 13, and a container treatment arrangement according to claim 17. Accordingly, in an initialization process, a gripper, in particular a first gripper, of the changeover robot is successively moved to a storage position of a plurality of treatment parts, and the position coordinates of the storage position are stored in a control device. Subsequently, in a changeover process, the changeover robot moves the gripper to at least one of the storage positions based on the position coordinates.

[0011] Accordingly, the invention provides that an initialization process precedes the actual exchange process, in which the treatment parts are replaced, in which the storage positions of the treatment parts are determined. For this purpose, the gripper of the exchange robot is moved to the storage position. After reaching the storage position, the position coordinates are then recorded by means of a detection device and stored in the control device. Thus, the position coordinates of the individual storage positions can be determined sequentially.

[0012] In this context, a particularly preferred design involves arranging the treatment parts in a common storage unit outside the tank treatment system. Such storage units are essentially a type of storage magazine through which the treatment parts can be stored together outside the tank treatment system. The individual storage positions are then traversed by the gripper, and their position coordinates are determined. Preferably, no gripping of the individual treatment parts occurs during the initialization process, when the storage positions are being determined.

[0013] According to a further development of the process, during the initialization process, the gripper is successively moved to a forming position for a multitude of parts within the container treatment system, and the position coordinates of each forming position are stored in the control device. This forming position is the position that the part being treated assumes within the container treatment system. Accordingly, the transfer robot performs a transfer between the storage position and the forming position. Subsequently, in the transfer process, the transfer robot moves the gripper to at least one of the forming positions based on the position coordinates.

[0014] According to this configuration, the initialization process thus comprises at least two steps. In the first step, the position coordinates of the stock positions are determined, and in the second step, the position coordinates of the mold positions are stored in the control device. These two steps can, in principle, be performed sequentially. Alternatively, it is also conceivable to perform both steps alternately, so that first a stock position and then a mold position of a processed part are determined.

[0015] According to a preferred embodiment of the method, the changeover robot first moves the gripper to a preliminary position during the initialization process. From there, the gripper is subsequently moved to the storage position or the mold position by a substantially linear movement along a guide direction. In this context, a substantially linear movement means that a deviation transverse to the guide direction is preferably less than 5 mm, and particularly less than 2 mm.

[0016] According to a particularly preferred embodiment of the invention, the changeover robot has a force measuring device, wherein the position coordinates of the storage position and / or the forming position are stored as soon as the force measuring device detects no force transverse to the guide direction – where “no force” within the meaning of the invention also includes a force reduced to such an extent that it is less than or equal to a predetermined permissible force. According to such an embodiment, gripping with the gripper is carried out solely by movement along a guide direction. Therefore, if no forces (or only forces less than or equal to a defined lower force) are detected transverse to the guide direction, it can be concluded that an adjustment of the position of the corresponding gripper is no longer necessary.Consequently, the gripper is already in a position where movement in the guide direction alone is sufficient to grasp the workpiece. Using such a force measuring device, it is therefore possible to record the position coordinates in such a way that the stock position or the forming position is reached as soon as subsequent movement of the gripper solely in the guide direction is required. Additionally, a force along the guide direction can also be recorded. This makes it possible, for example, to detect when the gripper comes to rest against the workpiece.

[0017] The force measuring device can preferably be a load cell. Furthermore, it is intended that the force measuring device preferably detects a force in all three spatial directions. Of course, it is also sufficient if only forces in the transverse direction to the guide direction are detected.

[0018] Preferably, in the initialization process, a second gripper of the exchange robot is successively moved to a storage position for a plurality of parts to be processed, and the position coordinates of these storage positions are stored in the control device. Subsequently, in the exchange process, the exchange robot moves the second gripper to at least one storage position based on these position coordinates. Such a configuration is particularly advantageous when different types of parts to be processed are to be picked up by the at least two grippers.

[0019] Accordingly, in the initialization process, the second gripper can then be successively guided into a forming position of a large number of treatment parts in the container treatment system, and the position coordinates of the forming position can be stored in the control device, and subsequently, in a changeover process, the changing robot moves the second gripper into at least one forming position based on the position coordinates.

[0020] Preferably, the grippers are guided into the storage positions and / or the forming positions by guide pins arranged parallel to the guide direction on the workpieces. Accordingly, the guide pins exert a force transverse to the guide direction if the first or second gripper is not positioned precisely. At the same time, the guide pins ensure that the grippers can be guided into the storage position or into the workpieces, and preferably, no force transverse to the guide direction acts on the force measuring device when these positions are reached.

[0021] The container treatment system is preferably a blow molding machine and has a plurality of magazine positions arranged circumferentially on a rotatably driven blow wheel for receiving treatment parts designed at least partially as blow molds, and wherein all magazine positions are occupied with a blow mold to determine the position coordinates of the mold positions in the initialization process.

[0022] Accordingly, the location of the magazine positions also defines the positional coordinates of the mold positions. Preferably, all magazine positions are occupied by a blow mold during the initialization process to determine the positional coordinates of the mold positions. This makes it possible to determine the positional coordinates of the stock positions sequentially. The positional coordinates are determined by moving the gripper into the mold position. However, gripping the blow mold itself is preferably not performed.

[0023] A further development of the invention provides that, after determining the positional coordinates of a mold position in the initialization process, the blowing wheel is rotated by a certain angular position. The invention is based on the understanding that the changeover robot is typically arranged at a substantially fixed position on the circumference of the blowing wheel. In order to be able to arrange the blow molds in all magazine slots or remove them from a magazine slot during the changeover process, a certain rotation of the blowing wheel is always necessary between two changeover steps. This rotation is now also necessary to determine the individual mold positions. The angular position required for the rotation depends essentially on the number of magazine slots. The usual number of magazine slots is between 6 and 36. Accordingly, the angular position is an angle between 60° and 10°.

[0024] A preferred embodiment of the invention provides that each blow mold is formed from at least two mold halves, which are pivotably arranged relative to each other within the blow molding machine. This design allows the preforms to be inserted easily and the blow mold then closed. Accordingly, it is generally sufficient within the scope of the invention if only one blow mold formed from two mold halves is provided per magazine position. However, according to a further development, a bottom mold is also arranged at each magazine position, so that the entire blow molding cavity required for the blow forming process is formed by the blow mold and the bottom mold. The bottom molds are typically inserted via the second gripper, with the first gripper being used for inserting the blow molds and the second gripper for inserting the bottom molds.

[0025] During the initialization process, the second gripper of the changeover robot is moved to a storage position for a multitude of base molds, and the position coordinates of these storage positions are stored in the control device. Subsequently, during the changeover process, the changeover robot moves the second gripper to at least one of the storage positions based on these position coordinates. Consequently, not only the position coordinates of the storage positions of the blow molds but also the position coordinates of the storage positions of the base molds are recorded. This preferably occurs after recording the storage data of the blow molds and, even more preferably, also after recording the position coordinates of the mold positions of the blow molds.

[0026] Subsequently, in the initialization process, the second gripper is successively moved into a shape position of one of a multitude of base shapes, and the position coordinates of each shape position are stored in the control device. Then, in the changeover process, the robot moves the second gripper to at least one of the shape positions based on these position coordinates.

[0027] In this context, a particularly preferred embodiment provides that, in order to record the mold positions, the individual blow molds were removed from the magazine slots of the blow wheel in advance.

[0028] After completion of the initialization process, the actual changeover process can begin, wherein in the changeover process the first gripper grasps a processing part, in particular a blow mold, in the storage position and places it in the mold position in the corresponding magazine slot, or wherein in the mold position in the corresponding magazine slot the processing part, in particular a blow mold, is grasped by the first gripper and placed in the storage position.

[0029] Similarly, during the changeover process, the second gripper can also grasp the processing part, in particular a base mold, in the storage position and place it in the corresponding magazine slot in the mold position. Alternatively, the second gripper can grasp the processing part, in particular a base mold, in the corresponding magazine slot in the mold position and place it in the storage position.

[0030] The invention further relates to a container treatment plant according to claim 12, in particular a blow molding machine for blow molding, in particular for stretch blow molding, of containers and an associated exchange robot, wherein the exchange robot is associated with a control device which is configured to carry out the methods according to the invention.

[0031] The interchangeable robot preferably has a force measuring device for detecting forces transverse to the guide direction, wherein the force measuring device can be connected to the control device via a signal connection, in particular wired or wireless. The force measuring device can also detect a force along the guide direction. This makes it possible, for example, to detect an end point.

[0032] Preferably, the treatment system is a blowing machine with a rotatably driven blowing wheel, which has a plurality of magazine positions arranged circumferentially.

[0033] Preferably, the blowing machine and the changing robot have a common direction of control.

[0034] The invention will now be explained in more detail using exemplary embodiments. The figures shown are: Fig. 1 a gripper which is not transferred to a stock position or mold position, Fig. 2 a gripper transferred to a storage position or mold position.

[0035] The Fig. Figure 1 shows a blow mold 1 and a changeover robot 2 with a first gripper 3, which is configured to grasp the blow mold 1 by means of a gripping device 4. This makes it possible to insert the blow mold 1 into a blow molding machine or to remove the blow mold from this blow molding machine.

[0036] With the aid of the changing robot 2, it is therefore possible to effect an automated change of the blow molds 1. However, for this to be possible, the required storage positions and / or mold positions of the blow mold 1 within a storage device and the blow molding machine must also be known.

[0037] For this purpose, the position coordinates of the stock position and the mold position are determined within an initialization process, whereby the determination of the positions is carried out in an analogous manner.

[0038] This is done according to the Fig. 1 of the grippers 3 is brought towards the blow mold 1, but according to the Fig. 1. There is an offset in a vertical direction V between the guide pins 5 of the blow mold 1 and the recesses 6 associated with the gripper 3. Accordingly, a force in the vertical direction V acts on the gripper 3, which is detected by a force measuring device 7 designed as a load cell. Due to the detection of a force in the vertical direction V, a repositioning of the gripper 3 is required.

[0039] This repositioning can be achieved solely by the design of the guide pins 5, which move the gripper 3 into the stock position or the mold position according to the Fig.2. The gripper 3 is then moved into its storage position, in which, in the example shown, no force component in the vertical direction V is detected. Instead, the gripper 3 can only be moved into this position by a guide direction F, which is perpendicular to the vertical direction V. In this storage position, the gripper 4 grasps the blow mold 1. After reaching this storage position, the position data can be transmitted to the control device 8. Transmission is possible as soon as the force measuring device 7 detects no force transverse to the guide direction F.

[0040] Using this method, the stock positions of blow mold 1 and then the mold positions of blow mold 1 are typically recorded and transmitted to the control device 8. The same procedure can then be used accordingly for the base molds, whereby the determination of the stock positions and the mold positions of blow mold 1 and the base molds is carried out independently of each other.

[0041] Based on the position coordinates stored in the control device 8, it is then possible to control the gripper 3 exactly according to the stored position coordinates and to effect a change of the blow molds 1 or the bottom molds. Reference symbol list 1 blow mold 2 swap robots 3 grippers 4 Gripping device 5 guide pins 6 exceptions 7 Force measuring device 8 Control device F Guidance direction V vertical direction

Claims

[1] Method for position matching between a gripper (3) of a changeover robot of a container treatment system, in particular a blow molding machine, and a treatment part to be gripped, wherein in an initialization process the gripper (3) of the changeover robot (2) is successively moved to a storage position of a plurality of treatment parts (1) and the position coordinates of the storage positions are stored in a control device (8) and wherein subsequently in a changeover process the changeover robot (2) moves the gripper (3) to at least one storage position on the basis of the position coordinates. [2] Method according to claim 1, wherein the treatment parts are arranged in the storage position in a common storage facility outside the container treatment plant. [3] Method according to one of the preceding claims, wherein in the initialization process the gripper (3) is successively guided into a forming position of a plurality of treatment parts in the blow molding machine and the position coordinates of the forming position are stored in a control device (8) and wherein subsequently in the changeover process the changeover robot (2) moves the gripper (3) into at least one forming position on the basis of the position coordinates. [4] Method according to one of the preceding claims, wherein the changeover robot (2) first moves the gripper (3) into a pre-position during the initialization process, from which the gripper (3) is subsequently moved into the storage position or the mold position by a substantially straight-line movement along a guide direction. [5] Method according to one of the preceding claims, wherein the changeover robot (2) has a force measuring device (7) wherein the position coordinates of the storage position and / or the form position are stored as soon as the force measuring device (7) does not detect a force transverse to the guide direction. [6] Method according to one of the preceding claims, wherein in the initialization process a second gripper (3) of the changeover robot (2) is successively moved into a storage position of a plurality of treatment parts and the position coordinates of the storage positions are stored in the control device (8) and wherein subsequently in the changeover process the changeover robot (2) moves the second gripper (3) to at least one storage position on the basis of the position coordinates. [7] Method according to one of the preceding claims, wherein in the initialization process the second gripper (3) is successively guided into a forming position of a plurality of treatment parts in the container treatment system and the position coordinates of the forming position are stored in the control device (8) and wherein subsequently in a changeover process the changeover robot (2) moves the second gripper (3) into at least one forming position on the basis of the position coordinates. [8] Method according to one of the preceding claims, wherein the grippers (3) are guided into the storage positions and / or the forming positions via guide pins (5) arranged parallel to the guide direction on the treatment parts. [9] Method according to one of the preceding claims, wherein the container treatment system is a blow molding machine and has a plurality of magazine positions arranged circumferentially on a rotatably driven blow wheel for receiving treatment parts designed at least partially as blow molds (1) and wherein, in order to determine the position coordinates of the mold positions in the initialization process, all magazine positions are occupied with a blow mold (1). [10] Method according to claim 9, wherein after determining the position coordinates of a mold position in the initialization process, the blow wheel is rotated by an angular position. [11] Method according to claim 9 or 10, wherein in the switching process the gripper (3) grasps a blow mold (1) in the storage position and places it in the mold position in the corresponding magazine space of the blow wheel or grasps a blow mold (1) in the mold position in the corresponding magazine space of the blow wheel and places it in the storage position. [12] Method according to one of the preceding claims, wherein in the switching process the second gripper (3) grasps a treatment part designed as a base form in the storage position and places it in the forming position in the corresponding magazine space of the blow wheel or grasps a base form in the corresponding magazine space of the blow wheel in the forming position and places it in the storage position. [13] Container treatment system for treating containers, in particular beverage containers, and an associated exchange robot (2), wherein the exchange robot (2) is associated with a control device (8) which is configured to carry out the method according to one of the preceding claims. [14] Container treatment system according to claim 13, wherein the changing robot has a force measuring device (7) at least for detecting forces transverse to the guide direction, wherein the force measuring device can be connected to the control device via a signal connection. [15] Container treatment plant according to claim 13 or 14, wherein the treatment plant is a blowing machine which has a rotatably driven blowing wheel with a plurality of magazine positions arranged in the circumferential direction. [16] Container treatment plant according to one of claims 13 to 15, wherein the blowing machine and the changing robot (2) have a common control device (8). [17] Container treatment arrangement with a container treatment system according to one of claims 13 to 16, wherein a treatment part is arranged on the gripper (3).

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