Body shell station for motor vehicles, method for operating a body shell station, and computer program product

Abstract

The present application relates to a body shell station for motor vehicles, to a method for operating a body shell station, and to a computer program product. The body shell station (1) for motor vehicles comprises: a plurality of storage racks (5) for receiving different clamping frame variants (4); a welding cell (2) having a plurality of welding robots (3) for welding different body components; at least two handling robots (6) for receiving and moving the clamping frame variants (4), each handling robot (6) being assigned a separate operating zone (7) in which at least one storage rack (5) is arranged; a transfer rack (8) which can be reached by both handling robots (6); and a controller which is designed to control the handling robots (6) in such a way that, in order for the handling robots to provide, in the welding cell (2), the particular clamping frame variant (4) appropriate for the body components to be welded by means of the welding robots (3), one of the handling robots (6) removes from the welding cell (2) a first clamping frame variant (4) to be removed from the welding cell (2) and the other handling robot (6) introduces a second clamping frame variant (4) into the welding cell (2).

Description

[0001] Body-in-white station for motor vehicles, method for operating a body-in-white station and computer program product

[0002] The present invention relates to a body-in-white station for motor vehicles, a method for operating a body-in-white station and a computer program product.

[0003] WO 2007 / 144114 A2 discloses a joining station for vehicle bodies. The joining station comprises a frame with at least one workstation, several clamping frames, at least one frame magazine, a frame changing device, and a machining device for the workpieces. The frame changing device has one or more multi-axis robots for changing and transferring the clamping frames to a positioning device on the frame.

[0004] Furthermore, DE 197 13860 A1 discloses a device for manufacturing complex workpieces, in particular vehicle bodies, in a production plant. Workpieces are transported sequentially along a transfer line through several workstations and processed there. Transport between the workstations is carried out by robot-assisted transport units, which preferably each consist of at least two transfer robots arranged on either side of the transfer line. The transfer robots lift the workpieces from one workstation to the adjacent workstation in a coordinated, synchronous movement and position them there. After transport, the transport units can change the tool and perform other machining operations on the workpieces.

[0005] A system for welding a side wall outer panel is known from CN 219484861 U.

[0006] Due to the often wide variety of vehicle models, there are various body component variants that need to be handled and welded in body-in-white stations. High flexibility in handling and welding different body component variants is therefore desirable. Furthermore, it is also desirable that body-in-white stations can be adapted to increasing variant diversity quickly and without excessive investment costs. Finally, such stations should not require excessive floor space.

[0007] The object of the present invention is to provide a solution by which different variants of body components can be handled and welded in a particularly simple and efficient manner and in particularly short cycle times.

[0008] This problem is solved by the subject matter of the independent claims. Further possible embodiments of the invention are disclosed in the dependent claims, the description, and the figures. Features, advantages, and possible embodiments set forth in the description for one of the subject matter of the independent claims are to be regarded, at least analogously, as features, advantages, and possible embodiments of the respective subject matter of the other independent claims, as well as of any possible combination of the subject matter of the independent claims, optionally in conjunction with one or more of the dependent claims.

[0009] The invention relates to a body-in-white station for motor vehicles comprising various clamping frame variants. Furthermore, the body-in-white station has several storage racks for receiving the clamping frame variants. The body-in-white station also includes a welding cell with several welding robots for welding different body components to at least one other body component. At least two handling robots, in particular stationary handling robots, are also part of the body-in-white station, wherein the handling robots are designed to move the clamping frame variants between the storage racks arranged in their respective working areas and the welding cell. It is possible for the body-in-white station to be symmetrical – and thus have two symmetrical sides – in which case the body-in-white station has, in particular, two handling robots per side.

[0010] Each handling robot is assigned a separate access area containing at least one storage rack. The body-in-white station also features a transfer rack accessible to both handling robots, allowing them to move the clamping frame variants between the storage racks within their respective access areas, the transfer rack, and the welding cell. Finally, the body-in-white station includes a control system configured to direct the handling robots to provide the appropriate clamping frame variants to the welding cell, corresponding to the body components to be welded by the welding robots.By controlling the handling robots in this way, one of the handling robots removes a first clamping frame variant from the welding cell, and the other handling robot introduces a second clamping frame variant, different from the first clamping frame variant, into the welding cell.

[0011] The different clamping frame variants are designed to accommodate various body components. Using a single clamping frame of one variant, several body components can be aligned relative to each other and held in this alignment. The storage racks of the body-in-white station serve to hold the different clamping frame variants. These racks are distributed throughout the body-in-white station in such a way that the respective handling robots can access some of them within their reach. This allows the handling robots to remove the clamping frame variants from the racks as needed and position them in the welding cell, and vice versa. Specifically, it is possible for one handling robot to act as the loading robot and another as the unloading robot for each cycle of the body-in-white station.This enables a particularly fast changeover of clamping frame variants. While one of the handling robots removes the clamping frame variant positioned in the welding cell, the other handling robot can already prepare the clamping frame variant suitable for the next welding process for placement in the welding cell.

[0012] It is specifically designed that the clamping frame variants are designed to hold the respective body side panels, with the welding cell being designed to weld the body side panels to a body substructure while the body side panels are fixed in place by the clamping frame variants. The respective body substructure and the body side panels can be fed to the body-in-white station and, in particular, to the welding cell using appropriate means. The body side panels can be, for example, inner or outer body side panels. In principle, it is possible to handle and weld a wide variety of body parts using the body-in-white station.

[0013] It is possible that a situation may arise in which both the clamping frame variant to be removed from the welding cell and the clamping frame variant to be placed in the welding cell are each assigned to a storage rack located in the same access area. One clamping frame variant is therefore placed onto its corresponding storage rack by the handling robot assigned to this access area, and the other clamping frame variant is removed from its corresponding storage rack by the same handling robot. A transfer rack is provided to enable a particularly quick changeover of the clamping frame variant within the welding cell.This is accessible to both handling robots and allows one robot to position the clamping frame variant being supplied to the welding cell within the welding cell, while the other robot removes the welding frame variant being removed from the welding cell. The transfer rack serves as an intermediate storage or transfer point for the welding frame variant between the handling robots. This allows one clamping frame variant to be removed from the welding cell particularly quickly using one robot, while the other robot is already picking up the new welding frame variant to be placed in the welding cell and preparing it for placement.Once the new welding frame variant is positioned in the welding cell, the handling robot that placed the welding frame variant in the welding cell can pick up the clamping frame variant removed from the welding cell and temporarily stored on the transfer rack, and place it on the designated storage rack. This allows for a particularly high number of cycles per given time unit, even if a change of welding frame variant is necessary between two cycles in the welding cell. It is possible to change the clamping frame variant after each welding of body components in the welding cell.

[0014] The body-in-white station according to the invention exhibits a particularly high degree of flexibility, enabling it to handle a large number of different vehicle types. Depending on the body components or variants to be welded, the body-in-white station can be easily expanded to accommodate additional vehicle types or variants by providing the appropriate clamping frame variants on the respective storage racks. This makes it possible to handle a wide variety of motor vehicles using the body-in-white station according to the invention, for which the various body components are to be welded together within the station.

[0015] In a possible further development of the invention, the respective bases of the handling robots are fixed in their position relative to the welding cell. This means that the respective bases of the handling robots are not movable or travelable relative to the welding cell. This significantly reduces the space required for the handling robots, as no space needs to be provided in the body shop for guide rails for the bases of the handling robots. Instead, the bases are in their fixed position relative to the welding cell, and only the respective robot arms of the handling robots can be moved relative to the fixed bases.

[0016] In a further possible embodiment of the invention, the transfer frame is fixed in its position relative to the engagement areas. Because the transfer frame cannot be moved relative to the respective engagement areas of the handling robots, it can be ensured that the transfer frame is always accessible to the handling robots assigned to the engagement areas closest to the transfer frame, so that these handling robots can reliably place clamping frame variants onto or remove them from the transfer frame.

[0017] In another possible embodiment of the invention, the transfer frame is designed to accommodate the clamping frame variants in an upright position. This means that the transfer frame and the clamping frame variants are coordinated such that the main extension direction of each clamping frame variant is oriented at least substantially vertically when the respective clamping frame variants are received by the transfer frame. This results in a particularly small footprint for the temporary storage of each clamping frame variant using the transfer frame. In terms of its footprint, the shell construction station can therefore be built very compactly. The transfer frame may also have at least one dovetail-shaped receiving area for hanging the respective clamping frame variants.This makes it possible to hang the respective tension frame variants on the transfer frame in a particularly simple yet reliable manner and thus position them on it.

[0018] In a further possible embodiment of the invention, each of the storage racks is assigned a specific clamping frame variant. This means that each storage rack is individually assigned to a clamping frame variant. This allows specific clamping variants to be arranged in the welding cell to be found particularly quickly, since it is known which storage rack corresponds to the clamping frame variant required in the welding cell. Furthermore, because each clamping frame variant is assigned a storage rack, it is ensured that all clamping frame variants can be placed simultaneously on their respective assigned storage racks. In addition, the control of the handling robots can be planned particularly well in advance, since the assignment between the respective clamping frame variants and storage racks is always clear.

[0019] In a further possible embodiment of the invention, the control system is configured to control the handling robots in such a way that a clamping frame change in a welding cell can be carried out within a maximum of ten seconds. This can be achieved by controlling the handling robots such that one handling robot removes a clamping frame variant from the welding cell, while the other handling robot—while the first is removing the clamping frame variant—is already preparing the clamping frame variant to be installed in the welding cell. This ensures that the state of the welding cell in which no clamping frame variant is installed exists only for a very short period of time.This particularly fast change of clamping frame variants using handling robots makes it possible to process, especially weld, a particularly large number of different body components within a given time interval.

[0020] In another possible embodiment of the invention, each handling robot is assigned up to four storage racks within its respective working area. If the body-in-white station comprises two handling robots on each symmetrical side, then the body-in-white station can again include up to 16 storage racks in total, thus providing up to 16 different clamping frame variants for arrangement on the respective storage racks in the welding cell. Providing up to four storage racks per handling robot allows for such an arrangement of the storage racks that each of these racks can be reached particularly easily and quickly by the handling robot, thereby enabling a particularly fast changeover of the clamping frame variant in the welding cell.The more storage racks, each assigned to a specific clamping frame variant, the body-in-white station comprises, the more different types of body components can be processed using this station. This allows for a so-called "wild mix" when processing different body types in the welding cell. "Wild mix" means that it is possible to change the clamping frame variant between all consecutive cycles, enabling the processing of different body types in each immediately following cycle.

[0021] The invention further relates to a method for operating a body-in-white station, as already described in connection with the body-in-white station according to the invention. In this method, the control system directs the handling robots in such a way that they provide the respective clamping frame variants in the welding cell, corresponding to the body components to be welded by the welding robots. This is achieved by one of the handling robots removing a first clamping frame variant from the welding cell, and the other handling robot introducing a second clamping frame variant, different from the first, into the welding cell.It is therefore not intended that the same handling robot be used in a single changeover operation to remove the clamping frame variant already installed in the welding cell and then, in the same process, to install the new clamping frame variant. Thus, two handling robots are always involved when changing a clamping frame variant in the welding cell, which allows for a particularly fast changeover.

[0022] In a possible further development of the invention, the handling robot, in whose reach the clamping frame variant to be arranged in the welding cell is placed on a storage rack, removes this clamping frame variant directly from the storage rack and arranges it in the welding cell. In other words, it is not provided that one of the handling robots removes the clamping frame variant to be arranged in the welding cell from its storage rack and temporarily stores it in the transfer rack until it is arranged in the welding cell. Instead, the respective clamping frame variant to be arranged in the welding cell, provided it is arranged on its storage rack, is removed directly from the storage rack and arranged in the welding cell by the handling robot in whose reach the storage rack is located.This prioritizes the supply of the clamping frame variant, which is primarily routed directly, bypassing the transfer rack. This allows the clamping frame variant to be newly installed in the welding cell to be removed from the storage rack and positioned in the welding cell particularly quickly using one of the handling robots. In this context, it may be specifically provided that the handling robot in whose reach the clamping frame variant to be installed in the welding cell is not located removes the clamping frame variant to be removed from the welding cell and places it on the storage rack assigned to this clamping frame variant, provided that this storage rack is located within the reach of this handling robot, or, if the storage rack assigned to this clamping frame variant is located within the reach of the other handling robot, places the clamping frame variant on the transfer rack.In other words, the plan is for a first handling robot, within whose reach the first clamping frame variant to be placed in the welding cell is located, to remove the first clamping frame variant from its assigned storage rack and prepare it for placement in the welding cell. Meanwhile, the second clamping frame variant, located in the welding cell and to be removed from the welding cell, is removed by a second handling robot and placed either on the transfer rack or on the storage rack assigned to this second clamping frame variant. The second handling robot places the second clamping frame variant on the storage rack assigned to this second clamping frame variant, provided that this storage rack is located within the reach of the second handling robot.If the storage rack on which the second clamping frame variant is to be placed is located within the reach of the first handling robot, then this second clamping frame variant is placed on the transfer rack by the second handling robot. As soon as the first handling robot has positioned the first clamping frame variant in the welding cell, the first handling robot is free again and can remove the second clamping frame variant from the transfer rack and place it on the storage rack assigned to this second clamping frame variant within the reach of the first handling robot.

[0023] This makes it possible to remove the second clamping frame variant from the welding cell and feed the first clamping frame variant to the welding cell using different handling robots, which allows this clamping frame variant change in the welding cell to be implemented particularly quickly.

[0024] In this context, a further development of the invention provides that the handling robot, in whose reach the clamping frame variant to be arranged in the welding cell had been placed on a storage rack, picks up the clamping frame variant arranged by the other handling robot on the transfer rack after the clamping frame variant has been arranged in the welding cell and places it on the storage rack assigned to this clamping frame variant. Thus, the second clamping frame variant is temporarily stored on the transfer rack until the first handling robot is free and can place the second clamping frame variant on the storage rack assigned to this second clamping frame variant within the reach of the first handling robot.The transfer frame thus provides a storage option or an intermediate storage option for clamping frame variants, which means that a change of a clamping frame variant in the welding cell can be implemented at any time by the two coordinated handling robots and is therefore carried out particularly quickly.

[0025] In a further possible embodiment of the invention, it is provided that, when the clamping frame variant to be arranged in the welding cell is located on the transfer frame, the clamping frame variant to be removed from the welding cell is removed by means of the handling robot in whose engagement area the storage frame for the clamping frame variant removed from the welding cell is located, and the clamping frame variant is transported from the transfer frame to the welding cell by means of the other handling robot and arranged in it.In other words: If it is determined, while the second clamping frame variant is temporarily stored on the transfer rack and the first clamping frame variant is arranged in the welding cell, that the first clamping frame variant subsequently needs to be removed from the welding cell and the second clamping frame variant re-arranged in the welding cell, then the first clamping frame variant is removed from the welding cell by the first handling robot and placed on the storage rack located within the reach of the first handling robot. The second handling robot then removes the second clamping frame variant from the transfer rack and places it in the welding cell.The second clamping frame variant is thus fed to the welding cell by the second handling robot, even though this second clamping frame variant would actually be assigned to a storage rack located within the reach of the first handling robot. If it is determined that the clamping frame variant located on the transfer rack needs to be placed back in the welding cell before the second clamping frame variant has been placed on its assigned storage rack by the first handling robot, then the second clamping frame variant can be transported to the welding cell by the second handling robot. This allows for a particularly fast changeover of clamping frame variants, even if the clamping frame variant to be placed in the welding cell is currently located on the transfer rack.In an alternative embodiment of the invention, it is provided that if the clamping frame variant to be arranged in the welding cell is located on the transfer rack, this clamping frame variant is transported from the transfer rack to the welding cell by the handling robot in whose reach the storage rack associated with this clamping frame variant is located, and arranged therein. The respective clamping frame variant to be arranged in the welding cell is thus positioned therein by the handling robot in whose reach the storage rack associated with this clamping frame variant is located, regardless of whether this clamping frame variant is currently on the storage rack or on the transfer rack. There is therefore a fixed assignment of the clamping frame variants to the handling robots with regard to their supply to the welding cell.This makes it clear at all times which handling robot is to be used to supply each clamping frame variant to the welding cell.

[0026] In another possible embodiment of the invention, the handling robot picks up the clamping frame variant to be next placed in the welding cell while body components are being welded in the welding cell using a clamping frame variant that will subsequently be removed from the welding cell. This means that the handling robot picks up the next clamping frame variant to be supplied to the welding cell and makes it ready for placement in the welding cell while body components are still being welded together in the welding cell. This allows a particularly large number of body components to be processed, especially welded, within a given timeframe in the body-in-white station, since changes between clamping frame variants in the welding cell can be carried out very quickly.

[0027] The invention further relates to a computer program product comprising instructions which, when executed, cause the control system of the body-in-white station, as already described in connection with the body-in-white station according to the invention, to control the handling robots in such a way that they execute the steps of the method according to the invention. Furthermore, the invention may relate to a computer-readable medium on which the computer program product according to the invention is stored.

[0028] Further features of the invention may become apparent from the following description of the figures and from the drawings. The features and combinations of features mentioned above in the description, as well as the features and combinations of features shown below in the description of the figures and / or in the figures themselves, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0029] The drawing shows in:

[0030] Fig. 1 shows a schematic perspective view of a body-in-white station for motor vehicles, which has several different clamping frame variants that can be handled by means of handling robots, and also shows several welding robots which serve to weld together a wide variety of body components;

[0031] Fig. 2 shows a schematic perspective view of a first storage rack, a second storage rack, and a transfer rack, wherein the first storage rack is assigned to a first engagement area of ​​a first handling robot and the second storage rack to a second engagement area of ​​a second handling robot; and

[0032] Fig. 3 shows a schematic top view of the shell construction station with two handling robots, a schematically depicted welding cell, several storage racks and the transfer rack.

[0033] Identical or functionally equivalent elements are marked with the same reference symbols in the figures.

[0034] Figure 1 shows a schematic perspective view from a top oblique angle of a body-in-white station 1 for a motor vehicle. The body-in-white station 1 comprises a welding cell 2 with several welding robots 3, which are configured to weld body components together. During welding, the respective body components to be joined are positioned relative to each other by means of a clamping frame variant 4 arranged in the welding cell 2, which is not shown in Figure 1. Furthermore, the body-in-white station 1 includes a plurality of storage racks 5 on which the respective clamping frame variants 4 can be placed. In this case, the body-in-white station 1 has eight different clamping frame variants 4, with each clamping frame variant 4 being individually assigned a storage rack 5. In other words, each of the storage racks 5 is assigned a specific clamping frame variant 4.The rough-in station 1 further comprises two handling robots 6, each of which is assigned an individual access area 7. In other words, the first handling robot 6 is assigned the first access area 7, and the second handling robot 6 is assigned the second access area 7. Both the first and second access areas 7 contain four storage racks 5, which can be reached by the respective handling robot 6 assigned to that access area 7. This means that the first handling robot 6 can remove the respective clamping frame variants 4 from all storage racks 5 in the first access area 7, or place the respective clamping frame variants 4 onto their assigned storage racks 5.The second handling robot 6 can remove clamping frame variants 4 from the storage racks 5 arranged in the second access area 7, or place clamping frame variants 4 onto their respective assigned storage racks 5 in the second access area 7. It is possible that the storage racks 5 in the second access area 7 are inaccessible to the first handling robot 6, and vice versa. In this configuration, the respective handling robots 6 are fixed at their bases relative to the welding cell 2 and relative to the storage racks 5. Different clamping frame variants 4 can be picked up and held by different storage racks 5. The rough-in station 1 also has a transfer rack 8, which can be reached by both handling robots 6.The transfer frame 8 is fixed in its position relative to the engagement areas 7. Furthermore, the transfer frame 8 is designed to receive the tension frame variants 4 placed on it in an upright position. The main direction of extension of the tension frame variants 4 is therefore at least substantially vertical when the tension frame variants 4 are arranged on their respective associated storage rack 5 or on the transfer frame 8.

[0035] Figure 2 shows a schematic perspective view of a first storage rack 5 of the first engagement area 7 on the far left, a second storage rack 5 of the second engagement area 7 on the far right, and the transfer rack 8 in the middle. It can be seen that the two storage racks 5 and the transfer rack 8 may be identical in construction.

[0036] The body-in-white station 1 further comprises a control system (not shown in the figures) configured to control the handling robots 6 so that they provide the appropriate clamping frame variant 4 in the welding cell 2 for the body components to be welded by the welding robots 3. In particular, it is provided that a clamping frame variant 4 to be removed from the welding cell 2 is taken out of the welding cell 2 by one of the handling robots 6, and the clamping frame variant 4 to be placed in the welding cell 2 is placed in the welding cell 2 by the other handling robot 6. This allows for a particularly fast changeover of a clamping frame variant 4 in the welding cell 2.In particular, the control system is configured to control the handling robots 6 in such a way that a changeover between the clamping frame variants 4 arranged in the welding cell 2 can be carried out within a maximum of ten seconds using the handling robots 6. The transfer rack 8 is thus designed as a kind of exchange storage unit and is located in an overlap area of ​​the two handling robots 6. This means that the transfer rack 8 can be reached by both handling robots 6.

[0037] Depending on which variants of the respective body components are to be handled and welded, the handling robots 6 select the appropriate clamping frame variant 4 and position it in the area of ​​the welding cell 2.

[0038] The fact that the clamping frame variants 4 in the welding cell 2 can be exchanged results in a particularly high degree of flexibility for the body-in-white station 1. For a wide variety of body variants and thus vehicle variants, it is therefore possible to handle and weld a wide variety of body components using the body-in-white station 1 in conjunction with the different clamping frame variants 4.

[0039] In order to enable a particularly fast change of a clamping frame variant 4 arranged in the welding cell 2, it is provided that the control system controls the handling robots 6 in such a way that they provide the assigned clamping frame variant 4 in the welding cell 2, corresponding to the body components to be welded by means of the welding robots 3, by one of the handling robots 6 removing a first clamping frame variant 4 from the welding cell 2 and the other handling robot 6 introducing a second clamping frame variant 4, which is different from the first clamping frame variant 4, into the welding cell 2.

[0040] Figure 3 shows a schematic top view of a section of the raw material assembly station 1. Figure 3 shows a first handling robot 6, hereinafter referred to as R1, and a second handling robot 6, hereinafter referred to as R2. Figure 3 also shows four storage racks 5, hereinafter referred to as A1 to A4, which are accessible to both the first robot R1 and the second robot R2. Storage racks R1A1 to R1A4 are located within the reach 7 of the first handling robot R1. Storage racks R2A1 to R2A4 are located within the reach 7 of the second handling robot R2. The transfer rack 8 can be reached by both handling robots R1 and R2. In the situation shown in Figure 3, all storage racks R2A1 to A4 assigned to the second handling robot R2 are occupied by their respective clamping frame variants 4.Furthermore, the storage rack R1A4 is equipped with a clamping frame variant 4. Additionally, the transfer rack 8 is equipped with a clamping frame variant 4, which is assigned a storage rack 5 located within the reach area 7 of the first handling robot R1. Furthermore, a clamping frame variant 4 is located in the welding cell 2, which is also assigned a storage rack 5 located within the reach area 7 of the first handling robot R1. Finally, the second handling robot R2 holds a clamping frame variant 4, which is also assigned a storage rack 5 located within the reach area 7 of the first handling robot R1.

[0041] Using the clamping frame variant 4 arranged in welding cell 2, which is hereinafter referred to as type 5, body components arranged on a first carriage 9 of the body-in-white station 1 are positioned relative to each other so that they can be welded together by the welding robots 3. After these body components have been welded, the first carriage 9 moves out of welding cell 2 and a second carriage 10 with further body components to be welded together moves into welding cell 2.After the body components arranged on the first slide 9 have been welded together, the clamping frame variant 4 arranged in the welding cell 2 must be changed, since the body components transported into the welding cell 2 by means of the second slide 10 must be positioned relative to each other during welding by means of another clamping frame variant 4, which is referred to below as type 3.

[0042] The delivery of the new clamping frame variant 4, to be arranged in welding cell 2, has priority. The clamping frame variant 4 is transported to welding cell 2 by the handling robot 6 whose reach 7 includes the storage rack 5 assigned to this clamping frame variant 4. In other words, the first handling robot R1 is intended to deliver the clamping frame variant 4 to welding cell 2 if a clamping frame variant 4 is to be arranged in welding cell 2 whose assigned storage rack 5 is designated R1A1, R1A2, R1A3, or R1A4. Furthermore, the second handling robot R2 is intended to deliver the clamping frame variant 4 to welding cell 2 if the clamping frame variant 4 to be delivered to welding cell 2 is assigned to one of the storage racks 5 designated R2A1, R2A2, R2A3, or R2A4.Here, the respective handling robot 6 can remove the clamping frame variant 4 from the assigned storage rack 5 or from the transfer rack 8, depending on where the clamping frame variant 4 is located. Feeding the respective clamping frame variant 4 to the welding cell 2 has priority for a particularly fast changeover of the clamping frame variant 4 in the welding cell 2. This means that the clamping frame variant 4 is fed directly to the welding cell 2. This means that the clamping frame variant 4 is picked up from the rack on which it is stored by one of the handling robots 6 and positioned in the welding cell 2. No transfer of this clamping frame variant 4 from one of the handling robots 6 to another, either directly or indirectly via the transfer rack 8, is provided.

[0043] Figure 3 shows a case in which the clamping frame variant 4, designated as type 3, is held by the second handling robot R2 and is to be placed next in the welding cell 2. In this case, in which the clamping frame variant 4 of type 3 has been removed from the welding cell 2 by the second handling robot R2 and has not yet been placed on the transfer rack 8, it is provided that this clamping frame variant 4 of type 3 is returned to the welding cell 2 by the second handling robot R2, even though this clamping frame variant 4 of type 3 is assigned to a storage rack 5, which is located in the engagement area 7 of the first handling robot R1.The second handling robot R2 returns the clamping frame variant 4 of type 3 to welding cell 2 after it has been removed from welding cell 2 by the second handling robot R2, provided that the clamping frame variant 4 of type 3 has been requested again and is not yet positioned on the transfer rack 8. Conversely, if the first handling robot R1 picks up a clamping frame variant 4 that is actually assigned to a storage rack 5 in the reach area 7 of the second handling robot R2, it must be returned to welding cell 2 to position the next body components to be welded together in welding cell 2 relative to each other.

[0044] To enable a particularly rapid changeover of the clamping frame variant 4 in welding cell 2, the handling robot 6 is specifically designed to pick up the clamping frame variant 4 that is to be placed next in welding cell 2, while body components are being welded in welding cell 2 using a clamping frame variant 4 that will subsequently be removed from welding cell 2. By picking up the clamping frame variant 4, the handling robot 6 thus prepares itself to place this clamping frame variant 4 in welding cell 2 particularly quickly after the removal of the clamping frame variant 4 that is still in welding cell 2.

[0045] The following describes a complete example of the process for changing a clamping frame variant 4 in welding cell 2. The first clamping frame variant 4 to be removed from welding cell 2 is taken out of welding cell 2 by the second handling robot R2 and placed on the assigned storage rack 5, provided that the storage rack 5 assigned to this first clamping frame variant 4 is within the reach area 7 of the second handling robot R2. However, if the storage rack 5 on which the first clamping frame variant 4 is to be placed is within the reach area 7 of the first handling robot R1, then the clamping frame variant 4 removed from welding cell 2 is placed on the transfer rack 8 by the second handling robot R2. The clamping frame variant 4 to be positioned in welding cell 2 is picked up by the first handling robot R1 and placed in welding cell 2.Here, the first handling robot R1 can remove the second clamping frame variant 4 from the transfer rack 8 or from the storage rack 5 assigned to this second clamping frame variant 4 within the reach area 7 of the first handling robot R1 and move it into the welding cell 2. After the first handling robot R1 has positioned the second clamping frame variant 4 in the welding cell 2 and the second handling robot R2 has positioned the first clamping frame variant 4 on the transfer rack 8, the first handling robot R1 can remove the first clamping frame variant 4 from the transfer rack 8 and place it on the storage rack 5 assigned to this first clamping frame variant 4 within the reach area 7 of the first handling robot R1.It can be provided that, if the clamping frame variant 4 to be arranged in welding cell 2 is located on the transfer rack 8, the clamping frame variant 4 to be removed from welding cell 2 is taken by the handling robot 6 in whose reach 7 the storage rack 5 for the clamping frame variant 4 taken from welding cell 2 is located, and the clamping frame variant 4 from the transfer rack 8 is transported to welding cell 2 by the other handling robot 6 and arranged therein. Alternatively, it can be provided that – as already described – if the clamping frame variant 4 to be arranged in welding cell 2 is located on the transfer rack 8, this clamping frame variant 4 is transported from the transfer rack 8 to welding cell 2 by the handling robot 6 in whose reach 7 the storage rack 5 assigned to this clamping frame variant 4 is located.The clamping frame variant 4 to be removed from welding cell 2 is taken out of welding cell 2 by means of the other handling robot 6.

[0046] The described invention is based on the understanding that known solutions for highly flexible framing systems often employ interchangeable systems based on gantry frames. Gantry-based systems have the disadvantage of requiring high initial investments, as the gantry frame must be purchased with the first model. Robot framing systems have the disadvantage that the changeover time is no longer achievable without impacting cycle times when output exceeding 30 jobs per hour, necessitating either cycle time losses or a sufficiently large block feed of the body variants. One such job is the welding of the body components of a body variant during a cycle. To achieve particularly high productivity, especially up to 60 jobs per hour, and simultaneously theoretically allow a change of the clamping frame variant 4 in each cycle, the transfer frame 8 is provided.This transfer frame 8 can also be referred to as a transfer station, in particular a flip-flop transfer station, or a transfer hub. The respective clamping frame variants 4 can be arranged vertically on the respective storage racks 5 or the transfer frame 8. Because the body-in-white station 1 has the two handling robots 6 and the eight storage racks 5, up to eight different body variants can be processed in the welding cell 2 with an output of up to 60 jobs per hour.

[0047] Body-in-white station 1 is part of an automated production line that can be operated in a so-called "wild mix" mode. This station, capable of processing body variants in a "wild mix," is highly flexible and does not extend the cycle time when changing the clamping frame variant 4 in welding cell 2; instead, it maintains a constant cycle time. The transfer rack 8 has a fixed position and can be operated by both handling robots 6. Each body variant can be assigned a clamping frame variant 4 with a fixed storage rack 5. When changing types, the clamping frame variant 4 is fed to the handling robot 6 in a timely manner. The storage rack 5 assigned to this clamping frame variant 4 is located within the robot's reach area 7. The transfer rack 8 thus enables demand-based feeding and return transport of the clamping frame variants 4 to their respective storage racks 5.As soon as a change of type with a clamping frame change is required from the same handling robot 6 or from the same access area 7, the concept of a robot framer with multiple vehicle types and a short cycle time would not function without a transfer frame 8. This disadvantage can be overcome by means of the control system, which can incorporate PLC logic. At the described body-in-white station 1, the timely delivery of a designated clamping frame variant 4 to the welding cell 2 within the cycle time can be guaranteed. In addition, a clamping frame variant 4 that is no longer needed and has been removed from the welding cell 2 can be returned in the background. Clamping frame variants 4 can be easily fed into and out of the body-in-white station 1, which can be implemented for expanding the range of types or for maintenance purposes.To enable a work productivity of 60 jobs per hour at body shop 1 with a cycle time of 51 seconds in a mixed-load operation, the control system directs the handling robots 6 in such a way that they can change the clamping frame variant 4 in welding cell 2 within a maximum of nine seconds. Furthermore, body shop 1 has a particularly small footprint.

[0048] In particular, the raw assembly station 1 has two sides that are symmetrically designed to each other, whereby for the sake of clarity, only one side (left or right) of the arrangement of the handling robots 6 and storage racks 5, which is in particular mirrored, is shown in Figs. 1 and 3. In Figs. 1 and 3, the axis of symmetry of the raw assembly station 1 is marked with reference numeral 11.

[0049] Overall, the invention demonstrates how a clamping frame change can be implemented via a flip-flop transfer station in a highly flexible robot assembly framer. Reference numeral list

[0050] 1 shell construction station

[0051] 2 welding cells

[0052] 3 welding robots

[0053] 4 welded frame variant

[0054] 5 storage rack

[0055] 6 handling robots

[0056] 7 Intervention area

[0057] 8 Transfer rack

[0058] 9 first sled

[0059] 10 second sled

[0060] 11 Axis of symmetry

[0061] R1 first handling robot

[0062] R2 second handling robot

[0063] R1A1 to R2A4 respective storage racks

Claims

Patent claims 1. Body shop (1) for motor vehicles, comprising different tension frame variants (4); several storage racks (5) for holding the clamping frame variants (4); a welding cell (2) with several welding robots (3) for welding different body components to at least one other body component; - at least two handling robots (6, R1, R2) for picking up and moving the clamping frame variants (4), wherein each handling robot (6, R1, R2) is assigned a separate access area (7) in which at least one storage rack (5) is arranged; with a transfer frame (8) which can be reached by both handling robots (6, R1, R2), enabling the handling robots (6, R1, R2) to move the clamping frame variants (4) between the storage racks (5) arranged in their respective engagement area (7), the transfer frame (8) and the welding cell (2), a control system which is set up to control the handling robots (6, R1, R2) in such a way that they provide the respective clamping frame variant (4) in the welding cell (2) to match the body components to be welded by means of the welding robots (3), whereby one of the handling robots (6, R1, R2) removes a first clamping frame variant (4) from the welding cell (2) and the other handling robot (6, R1, R2) introduces a second clamping frame variant (4) that differs from the first clamping frame variant (4) into the welding cell (2).

2. Raw construction station (1) according to claim 1, wherein the respective bases of the respective handling robots (6, R1, R2) are fixed in their position relative to the welding cell (2).

3. Shell construction station (1) according to claim 1 or 2, wherein the transfer frame (8) is fixed in its position relative to the engagement areas (7).

4. Shell construction station (1) according to one of the preceding claims, wherein the transfer frame (8) is configured to receive the tension frame variants (4) upright.

5. Raw construction station (1) according to one of the preceding claims, wherein each of the storage racks (5) is assigned a specific tension frame variant (4).

6. Shell construction station (1) according to one of the preceding claims, wherein the control is configured to control the handling robots (6, R1, R2) in such a way that a clamping frame change in the welding cell (2) can be carried out by means of the handling robots (6, R1, R2) within a maximum of 10 seconds.

7. Raw construction station (1) according to one of the preceding claims, wherein each of the handling robots (6, R1, R2) is assigned up to four storage racks (5) in its respective engagement area (7).

8. Method for operating a body-in-white station (1) according to one of the preceding claims, in which the control system controls the handling robots (6, R1, R2) in such a way that they provide the respective clamping frame variant (4) in the welding cell (2) to match the body components to be welded by means of the welding robots (3), by one of the handling robots (6, R1, R2) removing a first clamping frame variant (4) from the welding cell (2) and the other handling robot (6, R1, R2) introducing a second clamping frame variant (4) that differs from the first clamping frame variant (4) into the welding cell (2).

9. Method according to claim 8, wherein the handling robot (6, R1, R2), in whose engagement area (7) the clamping frame variant (4) to be arranged in the welding cell (2) is placed on a storage rack (5), removes this clamping frame variant (4) directly from the storage rack (5) and arranges it in the welding cell (2).

10. Method according to claim 8 or 9, wherein the handling robot (6, R1, R2), in whose engagement area (7) the clamping frame variant (4) to be arranged in the welding cell (2) is not placed, removes the clamping frame variant (4) to be removed from the welding cell (2) and on the storage rack (5) assigned to this clamping frame variant (4), provided that this storage rack (5) is arranged in the engagement area (7) of this handling robot (6, R1, R2), or provided that the storage rack (5) assigned to this clamping frame variant (4) is located in the access area (7) of the other handling robot (6, R1, R2), the clamping frame variant (4) is placed on the transfer rack (8).

11. Method according to claim 10, wherein the handling robot (6, R1, R2), in whose engagement area (7) the clamping frame variant (4) to be arranged in the welding cell (2) had been placed on a storage rack (5), picks up the clamping frame variant (4) arranged by the other handling robot (6, R1, R2) on the transfer rack (8) and places it on the storage rack (5) assigned to this clamping frame variant (4).

12. Method according to one of claims 8 to 11, wherein, when the clamping frame variant (4) to be arranged in the welding cell (2) is located on the transfer frame (8), the clamping frame variant (4) to be removed from the welding cell (2) is removed by means of the handling robot (6, R1, R2) in whose engagement area (7) the storage frame (5) for the clamping frame variant (4) removed from the welding cell (2) is located, and the clamping frame variant (4) is transported from the transfer frame (8) to the welding cell (2) by means of the other handling robot (6, R1, R2) and arranged in it.

13. Method according to one of claims 8 to 11, wherein, when the clamping frame variant (4) to be arranged in the welding cell (2) is located on the transfer frame (8), this clamping frame variant (4) is transported from the transfer frame (8) to the welding cell (2) by means of the handling robot (6, R1, R2) and is arranged in the welding cell (2) in whose engagement area (7) the storage frame (5) associated with this clamping frame variant (4) is located.

14. Method according to one of claims 8 to 13, wherein the handling robot (6, R1, R2) already picks up the clamping frame variant (4) to be arranged next in the welding cell (2), while body components are welded in the welding cell (2) using a clamping frame variant (4) to be subsequently removed from the welding cell (2).

15. Computer program product comprising instructions which, when executed, cause the control of the shell construction station according to one of claims 1 to 7 to control the handling robots in such a way that they perform the steps of the method according to one of claims 8 to 14.

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