Production plant for the series production of motor vehicles and process for manufacturing a motor vehicle

Abstract

Production plant (10) for the series production of motor vehicles (100, 102) of different motor vehicle types and / or different model variants, with the following features: - the production plant (10) has several workstations (20, 22) at each of which at least one predetermined work process for the series production of the motor vehicle (100, 102) can be carried out, and - the workstations (20, 22) are interconnected so that, after completion of the work process at one workstation (20), the motor vehicle (100, 102) to be produced can be transported to the next workstation (22), and are characterized by the following features: - at least one workstation (20) has a receiving area (30) on which at least two load carriers (40) with components (42, 44) can be placed for the specified work process, - the workstation (20) has an upstream zone (60) in which a large number of load carriers (40) with components (42, 44) for the workstation (20) are kept, - the production plant (10) has a transport system (50) which is suitable for delivering the load carriers (40) with components (42, 44) to the receiving area (30) and for picking up empty load carriers (40') from the receiving area (30), and - the receiving area (30) is designed for the placement of load carriers (40) with different components (42, 44) for motor vehicles (100, 102) of different vehicle types and / or different model variants.

Description

[0001] The invention relates to a manufacturing plant for the series production, in particular of motor vehicles, according to the preamble of claim 1, and to a method for manufacturing a motor vehicle with such a manufacturing plant.

[0002] Batch production is a type of manufacturing characterized by the simultaneous or immediately successive production of several identical products (batch), also called batch products. In batch production, both identical products and products with different manufacturing processes can be produced on a single production line.

[0003] Production lines for series manufacturing typically have several workstations, each capable of performing at least one predetermined work process for manufacturing, for example, a motor vehicle. These workstations are interconnected, allowing the vehicle being produced to be transported to the next workstation after the completion of the work process at one station. Each workstation usually has a receiving area where a load carrier containing components for the specified work process can be placed. The load carriers are generally delivered via a transport system, most often a tugger train, also known as a logistics train. These transport systems are designed for internal, usually horizontal, material transport within the plant.The transport systems typically comprise transport units that primarily supply workstations with components from a remote logistics area on a just-in-time basis. These logistics areas are often warehouses and are sometimes referred to as "supermarkets." The transport systems can include multiple transport units, each capable of carrying load carriers containing components, enabling a large volume of material to be transported in a single trip while minimizing internal traffic. Therefore, tugger trains are considered the most economical and safest solution for horizontal material flows within a company.

[0004] The transport system is also typically used to collect empty load carriers from the receiving area, thereby freeing up space for a new load carrier with components.

[0005] Mass production of motor vehicles is always associated with high costs. To reduce manufacturing costs, production facilities are often used flexibly today, meaning that several model variants are produced simultaneously on a single production line. These different model variants are often based on uniform or similar vehicle platforms. As a rule, such model variants share at least some of the structural, mechanical, and / or technical components used. Such vehicle platforms enable the construction of a greater variety of different model variants from a basic set of components. Since different model variants of motor vehicles are generally manufactured from at least partially different components, it is necessary to maintain load carriers containing various components at individual workstations.Switching between different components is often time-consuming. Changing between different model variants typically involves changeover times and costs, which are significant in series production.

[0006] A system that primarily relies on just-in-time component delivery to workstations is generally not dynamic or requires a very high level of logistical organization, as the aforementioned transport systems with tugger trains spend a considerable amount of time traveling between the logistics area and the workstation receiving areas. Just-in-time delivery is particularly problematic with autonomous transport systems, as other operational traffic between the workstations and the logistics area, or disruptions such as pedestrians, can often slow these systems down. This can lead to increased traffic from the transport systems, which in turn can delay other component deliveries. For this reason, waiting positions for the load carriers containing components are often necessary.

[0007] To increase the efficiency of existing systems, attempts are often made to replace tugger trains with automated guided vehicles (AGVs). This requires either sufficient picking areas at the workstations or that the AGV's operating schedule be linked to the production line cycle time. The latter is very difficult to implement due to the dynamic safety technology of AGVs and is inherently prone to malfunctions.

[0008] WO 2014 026072 A1 discloses production facilities for series production where the various workstations can request new load carriers containing components, so that these are delivered just-in-time depending on the remaining runtime of the work process at the workstation. To bridge any waiting times for new load carriers with components, these production facilities are equipped with so-called buffer stations. The transport system can temporarily store the load carriers at these buffer stations if they are not yet ready for delivery to the workstation.

[0009] From DE 10 2017 220 176 A1, a method for operating a production plant is known in which several buffer stations are provided for the temporary storage of load carriers containing components. A buffer station is provided both before and after each workstation. The workstation can therefore be loaded and unloaded even if workpieces are present at the workstation and at the buffer station before the workstation, but no workpieces are present at the buffer station after the workstation.

[0010] DE33 33 993 A1 discloses a method for assembling workpieces consisting of several parts using a robot. The parts are fed to a gripping area of ​​the robot via trays. According to the work sequence, the trays contain various parts, which are then assembled to form the workpiece.

[0011] DE 19 713 860 A1 discloses a method and a device for manufacturing vehicle bodies in a production plant. The vehicle bodies are transported along several workstations, with the workpieces being transported between the workstations by robot-assisted transport units.

[0012] WO 2006 063541 A1 discloses an assembly system with at least two assembly cells. Each assembly cell has pallet positions designed as buffer positions. A portion of these buffer positions is assigned to at least two assembly cells simultaneously.

[0013] The main objective of the present invention is to provide a production plant for the series production, particularly of motor vehicles, which features an improved system for supplying workstations with new load carriers containing components. The invention also encompasses production plants designed for the series production of modular units. In such a production plant, the components are sets of parts that can be assembled into modular units at the workstations. A production plant according to the invention makes it possible to minimize downtime when changing load carriers, so that no downtime is necessary in the work process when a load carrier is empty.A further advantage of using the production plant according to the invention is that this production plant can be used flexibly for several different motor vehicles and / or for several different model variants simultaneously. Furthermore, the production plant according to the invention allows for the installation of an additional motor vehicle and / or an additional model variant without requiring a production interruption (so-called hard changeover).

[0014] The object of the invention is to further develop a generic manufacturing plant in such a way that the aforementioned disadvantages of the prior art are avoided or reduced.

[0015] According to the invention, this is achieved by means of a production plant which has the following features. The production plant has several workstations, at each of which at least one predetermined work process for the series production of the motor vehicle can be carried out. The workstations are interconnected so that, after completion of the work process at one workstation, the motor vehicle to be produced can be transported to the next workstation.

[0016] It is proposed here to further develop the production plant so that at least one workstation has a receiving area where at least two load carriers containing components for the specified work process can be placed. It is further proposed that the workstation have an upstream zone where a large number of load carriers containing components for the workstation are stored. The production plant also has a transport system suitable for delivering the load carriers with components to the receiving area and for collecting empty load carriers from the receiving area.

[0017] This principle allows multiple load carriers containing identical components to be kept on hand, so that the work process at the workstation does not need to be interrupted if one of the load carriers is empty. For example, if a robot positioned at the workstation is empty, it can use the components from a second load carrier. In the meantime, the empty load carrier can be replaced with a new one containing components.

[0018] The components can be a large number of identical parts, but it is also conceivable that the components are stored in a sequence intended for use in different vehicles. This type of component inventory is also known as just-in-sequence.

[0019] Preferably, the distance between the upstream zone and the workstation is coordinated with the speed of the transport system and the cycle time of the work process such that a change of load carrier is possible even within the cycle time of the workstation. The distance between the upstream zone and the workstation is therefore preferably dimensioned such that, within one system cycle, the transport system can pick up an empty load carrier and place a new load carrier with components at the receiving area of ​​the workstation. From the next cycle onward, the component from the new load carrier can then be used.

[0020] The receiving area can be designed to accommodate load carriers, each containing different components required for different vehicle types and / or model variants. Preferably, the receiving area is designed to accommodate load carriers, each containing different components, for vehicles of different types and / or for several different model variants.

[0021] Another advantage of this design is that, for example, when setting up another variant of the vehicle being produced, no production interruption is necessary, since the load carriers with the corresponding new components can be placed at the workstation's receiving area without having to first remove the load carriers containing the components of the vehicles produced up to that point. Thus, one position in the receiving area can be equipped with a load carrier containing the components currently being installed, and a second position with a load carrier containing the components for the next variant of the vehicle being produced. It is therefore unnecessary to first remove all the load carriers for the vehicle already assembled from the production line and then position all the load carriers with the new components at the production line.Such a change can take place during ongoing operations.

[0022] The production plant can also be designed for the simultaneous series production of different vehicle types and / or several different model variants. This means that different vehicle types and / or different model variants can be manufactured sequentially or in mixed operation on a single production plant. Therefore, no downtime of the production plant is required to switch between the different vehicle types and / or different model variants. The production plant according to the invention is particularly advantageous when used for different vehicles and / or several different model variants.

[0023] If the workstation's loading area can accommodate multiple load carriers, it allows for the particularly efficient storage of different components for various vehicles and / or multiple model variants. In such a configuration, for example, one load carrier could contain the component for a first vehicle type, and a second load carrier the component for a second vehicle type. As soon as one of the load carriers is empty, a new one containing components from the upstream zone can be added. Preferably, this changeover can occur within the workstation's cycle time, as described above. This ensures that even if the component from the empty load carrier is still needed, the system does not have to stop.

[0024] Preferably, the production facility includes a logistics area where numerous load carriers containing components for the upstream workstation zone can be stored. This logistics area can be located some distance from the upstream zone, as the upstream zone can serve as a buffer zone. This configuration ensures that the production facility does not have to shut down due to a lack of components, even under high capacity utilization. The components can therefore be transported from the logistics area to the upstream workstation zone and stored there until needed.

[0025] The transport system is preferably designed as an automated guided vehicle (AGV). An AGV is typically a floor-mounted conveying device with its own drive system, which is automatically controlled and / or guided without physical contact. AGVs are used for material transport, specifically for pulling or carrying load carriers with active or passive load-handling devices. Preferably, the transport units are AGVs in accordance with VDI guideline 2510 "Automated Guided Vehicles".

[0026] The transport system is preferably automated and / or centrally controlled. It is also possible for the transport system to be non-centrally controlled and, for example, receive control signals from the workstation. Preferably, the transport system is capable of delivering the load carriers to both the upstream zone and the receiving area. Preferably, it is a single transport system that can deliver the load carriers, for example, from the logistics area to the upstream zone, as well as the load carriers from the upstream zone to the receiving area of ​​the workstations. The transport system preferably has several individual and independent transport units. The individual transport units can be connected to each other so that they can form a tugger train.

[0027] The invention further relates to a method for operating a production plant for the series production, in particular of motor vehicles. The production plant comprises the production plant of the type described.

[0028] The system envisages that at least one predetermined work process for the production of the motor vehicle is initially carried out at a workstation. Components required for the predetermined work process are delivered on a load carrier from an upstream zone, where numerous load carriers containing components for the workstation are stored, to a receiving area of ​​the workstation via a transport system. This step is only necessary if no load carrier containing components is available in the receiving area of ​​the workstation.

[0029] The components are removed from the load carrier during at least one of the work processes. Typically, not all components are removed from the load carrier during this step. The vehicle being produced is then transported to the next workstation. This step is carried out at the respective workstation after completion of at least one predetermined work process for manufacturing the vehicle.

[0030] An empty load carrier is preferably picked up from the workstation's receiving area using the transport system. It may also be possible to transport a previously placed load carrier away from the workstation using a transport unit.

[0031] Preferably, the transport units of the transport system remain together with the load carriers at the respective receiving areas of the workstations. In this way, the need to unload and reload the load carriers can be avoided.

[0032] Preferably, load carriers with different components are placed at the receiving area. This allows different motor vehicles and / or several different model variants to be produced at the production plant.

[0033] Preferably, the load carriers are transported by means of the transport system from a logistics area, in which a large number of load carriers with components for the upstream zone of the workstation are kept, to the upstream zone.

[0034] Further preferred embodiments of the invention result from the other features mentioned in the dependent claims.

[0035] Unless otherwise stated in individual cases, the various embodiments of the invention mentioned in this application can be advantageously combined with one another.

[0036] The invention is explained below in an exemplary embodiment with reference to the accompanying drawing. It shows: Fig. 1 a manufacturing plant according to the invention for the series production of motor vehicles.

[0037] Fig. Figure 1 shows a top view of a production plant 10 for the series production of several different model variants of motor vehicles 100, 102. The production plant 10 has several workstations 20, 22, at which a predetermined work process for the series production of the motor vehicles 100, 102 is carried out by means of a robot 24, 26. The workstations 20, 22 are interconnected so that after completion of the work process at workstation 20, the motor vehicle 100, 102 to be produced can be transported to the next workstation 22. In this embodiment, this transport takes place by means of a conveyor belt 28.

[0038] Workstation 20 has a receiving area 30 where two load carriers 40 containing components 42 and 44 can be placed for the specified work process. The receiving area 30 is designed to hold load carriers 40, each containing different components 42 and 44. The different components 42 and 44 ensure that the various model variants of motor vehicles 100 and 102 can be equipped with the appropriate components 42 and 44.

[0039] A forward zone 60 is assigned to workstation 20, in which five load carriers 40 with components 42, 44 for workstation 20 are kept.

[0040] The production plant 10 has a transport system 50, which is suitable for delivering the load carriers 40 containing components 42, 44 to the receiving area 30 and for picking up empty load carriers 40' from the receiving area 30. The transport system 50 has individual transport units 52, which are designed as driverless transport systems.

[0041] One of the positions in pickup area 30 of workstation 20 is unoccupied. An empty load carrier 40' was removed from this pickup area 30 of workstation 20 by a transport unit 52 of the transport system 50 and is being transported away on a track 64. Simultaneously, a full load carrier 40 containing components 42 is being moved from the upstream zone 60 to pickup area 30 of workstation 20. The full load carrier 40 containing components 42 is intended for the unoccupied pickup area 30 of workstation 20. This creates another empty position 62 in the upstream zone 60. The distance between the upstream zone 60 and workstation 20 is dimensioned such that the exchange of the load carriers 40 and 40' can take place within one cycle time of the robot 24.

[0042] The production facility 10 has a remote logistics area 70, in which a large number of load carriers 40 with different components 42, 44 are kept for the upstream zone 60 of the workstation 20.

[0043] The training station 62 of the upstream zone is restocked with a load carrier 40 containing components 44. A transport unit 52 of the transport system 50 brings the load carrier 40 with components 44 from the remote logistics area 70 to the upstream zone 60. The distance between logistics area 70 and the upstream zone 60 is dimensioned such that the provision of load carriers 40 with components 42, 44 occurs within the production time per container (this is generally calculated as the cycle time of the system multiplied by the number of components 42, 44 in the load carrier 40). This design allows several different model variants of motor vehicles 100, 102 to be manufactured on the production line 10 without interruption. Reference symbol list 10 production plant 20, 22 workstation 24, 26 robots 28 conveyor belt 30 recording area 40 load carriers 40' empty load carrier 42, 44 Component 50 transport systems 52 transport units 60 upstream zone 62 empty spaces 64 Road 70 Logistics area 100, 102 Motor vehicle

Claims

Production plant (10) for the series production of motor vehicles (100, 102) of different vehicle types and / or different model variants, with the following features: - the production plant (10) has several workstations (20, 22) at each of which at least one predetermined work process for the series production of the motor vehicle (100, 102) can be carried out, and - the workstations (20, 22) are interconnected so that, after completion of the work process at one workstation (20), the motor vehicle (100, 102) to be produced can be transported to the next workstation (22), and characterized by the following features: - at least one workstation (20) has a receiving area (30) at which at least two load carriers (40) with components (42, 44) for the predetermined work process can be placed, - the workstation (20) has an upstream zone (60),in which a large number of load carriers (40) with components (42, 44) for the workstation (20) are kept,- the production plant (10) has a transport system (50) which is suitable for delivering the load carriers (40) with components (42, 44) to the receiving area (30) and for picking up empty load carriers (40') from the receiving area (30), and- the receiving area (30) is designed for storing load carriers (40) with different components (42, 44) for motor vehicles (100, 102) of different vehicle types and / or different model variants. Production plant (100) according to claim 1 with the following further feature: - the production plant (100) is designed for the simultaneous series production of motor vehicles (100, 102) of different motor vehicle types. Manufacturing plant (100) according to one of the preceding claims with the following further feature: - the transport system (50) is designed as a driverless transport system; preferably with the additional feature: - the transport system (50) is suitable for delivering the load carriers (40) both to the upstream zone (60) and to the receiving area (30). Manufacturing plant (100) according to one of the preceding claims with the following additional feature: - the transport system (50) has at least two transport units (52), each of which transports a load carrier (40). Manufacturing plant (100) according to one of the preceding claims with the following additional feature: - the manufacturing plant (10) has a logistics area (70) in which a large number of load carriers (40) with components (42, 44) for the upstream zone (60) of the workstation (20) can be stored. Method for operating a production plant (10) for the series production of motor vehicles (100, 102) of different vehicle types and / or different model variants according to one of the preceding claims, comprising the following steps: - at least one predetermined work process for the manufacture of the motor vehicle (100, 102) is carried out at a workstation (20), and - components (42, 44) necessary for the predetermined work process are delivered on a load carrier (40) from an upstream zone (60), in which a plurality of load carriers (40) with components (42, 44) for the workstation (20) are kept, by means of a transport system (50) to a receiving area (30) of the workstation (20), and - at least a part of the components (42, 44) is removed from the load carrier (40) during at least one work process, and - the motor vehicle (100) to be produced is transported to a next workstation (22).and- several load carriers (40) with different components (42, 44) are placed at the receiving area (20). Method according to claim 6 with the following further step: - the empty load carrier (40') is transported away from the receiving area (30) of the workstation (20) by means of the transport system (50). Method according to one of claims 6 to 7 with the following further step: - the load carriers (40) are brought by means of the transport system (50) from a logistics area (70) in which a plurality of load carriers (40) with components (42, 44) for the upstream zone (60) of the workstation (20) are kept, to the upstream zone (60).

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