Production line and trolley for use therein

Abstract

A production line for processing workpieces in successive steps, comprising a plurality of stations and a plurality of trolleys (16, 22), each of said trolleys comprising a first connector (46, 48), said plurality of stations comprising at least one work station (1) adapted to perform therein an associated one of said steps and at least one loading station (1) comprising a second connector (50, 51) for providing a load to one of said trolleys (16, 22) when connected to the first connector (46, 48) of said one trolley. At least one of said trolleys (16) comprises a second connector (46, 48) in communication with the first connector (46, 48).

Description

Technical Field

[0001] The invention relates to a production line and a trolley for use in the production line. Background Technology

[0002] With the introduction of assembly lines, it has become a paradigm for cost-effective mass production that workpieces should undergo the same processing steps: the same processing steps are applied to all workpieces by transferring them from one workstation performing one processing step to the next, and the same final product is output at the last workstation in the series. Ideally, these workstations would be adjacent to each other so that a workpiece, after being processed at one workstation, can be forwarded to the next with minimal time loss. Nevertheless, time is wasted in such production lines when the cycle times of the workstations differ, and fast workstations are forced to wait for the slower workstations to complete their tasks before they can forward the workpieces they have already processed to the subsequent, slower workstations and accept another workpiece.

[0003] Computer control has allowed for more flexible production schemes where trolleys can be used to transport workpieces along different paths between workstations. These trolleys can move more or less freely on the shop floor, provided there is enough space for them to pass through. This allows a workstation that has finished its work on a given workpiece to release that workpiece onto a trolley and immediately accept a new workpiece, while the trolley can transport the workpiece to any of several workstations dedicated to the next processing step, which happens to be idle or will soon finish its current workpiece. In such a production line, efficiency suffers because trolleys need to be reloaded and are therefore unavailable, or if a trolley performing a reloading operation blocks the path of a busy trolley. Of course, a shortage of operable trolleys can be prevented by providing a large number of trolleys, but the larger the number, the more likely they are to block each other's paths. By providing charging stations far from the workstations, charging trolleys can be prevented from blocking busy trolleys, but charging trolleys will still occupy a considerable amount of space that could be better utilized, and moving to and returning from charging stations also keeps the trolleys unproductively occupied. Summary of the Invention

[0004] Therefore, the object of the present invention is to provide an efficient production line and a trolley for use in such a production line.

[0005] According to a first aspect of the invention, this objective is achieved by a production line for processing workpieces in a series of steps, the production line comprising a plurality of stations and a plurality of trolleys, each trolley including a first connector, the plurality of stations including at least one workstation and at least one loading station, the at least one workstation being adapted to perform associated steps in the series of steps therein, the at least one loading station including a second connector for supplying goods to one of the trolleys when connected to the first connector of the trolley, wherein the at least one trolley includes a second connector communicating with the first connector.

[0006] When the first connector of the trolley is connected to the second connector of the loading station, the trolley can not only receive the goods provided by the loading station, but also forward the goods to a second trolley that docks with its second connector. Therefore, the number of loading stations can be reduced, and those spaces (which would otherwise be necessary) can be put into more productive use.

[0007] In a preferred embodiment, at least one of the workstations is also a loading station. This allows the trolley to pick up goods while it is at the workstation, thereby reducing unproductive time spent on loading. The higher the percentage of workstations that are also loading stations, the more frequently the trolley can reload without abandoning productive work, and the smaller the percentage of downtime spent at stations that are only loading stations. Ideally, the percentage of workstations that are also loading stations is so high that there may be no workstations that are only loading stations.

[0008] The cargo to be reloaded can be any one of electricity, data, fuel, compressed gas, or vacuum. Preferably, it includes at least one of electricity and compressed gas. The possibility of frequent reloading at several workstations accessed during the trolley's operating cycle reduces storage capacity requirements, which in turn reduces the cost and weight of the trolley.

[0009] By making the second connector of the trolley identical to the second connector of one of the loading stations, it is ensured that the trolley can be reloaded either by directly docking to the loading station or by docking to another trolley already loaded there. Therefore, there is no time loss while waiting for a reloading opportunity. Furthermore, when the loading station is also a workstation, the trolley can thus make good use of the time it spends waiting while the workstation is busy handling workpieces being transported by another trolley docked between it and the workstation.

[0010] In a particularly preferred embodiment, the storage space of the trolley is a dustproof compartment having at least one port adapted to be coupled in a dustproof manner to a mating port of the at least one workstation. This dustproof compartment is particularly useful for transporting newly painted workpieces, i.e., in a production line where the processing step associated with at least one of the workstations is a painting step.

[0011] The ports of the trolley and / or workstation preferably include sliding doors. After the ports of the trolley and workstation have been positioned in a mating relationship, the sliding doors can be opened to minimize dust entry through the gaps between the ports, or dust entry can be completely prevented by a slight positive pressure in the compartment and / or workstation.

[0012] The door should include a flexible panel. By shifting a panel that continuously surrounds the edge of the compartment from the front facing the workstation to, for example, the side wall or top of the compartment, a sliding door can almost fill the entire front and can still be opened without increasing the size of the trolley.

[0013] To facilitate loading and unloading of workpieces, the trolley may include a track section for movable support of the workpiece. When this track section is coupled to the track of the workstation, the workpiece can be easily and smoothly transferred along the track and the track section.

[0014] In a production line, two or more workstations should have ports through which workpieces can be transferred to or received from a trolley. Thus, a trolley can pick up a workpiece at the port of one workstation and select the workstation to which it will be delivered, or it can collect workpieces from several workstations and deliver them to the same target workstation.

[0015] To minimize the idle time of the workstation, the workstation should have at least two ports to which the trolley can be coupled, so that loading a workpiece to be processed on one trolley and unloading the next workpiece to be processed from the other trolley can be done simultaneously at different ports.

[0016] According to a second aspect of the invention, this objective is achieved by a trolley comprising a motorized and maneuverable chassis, a storage space for workpieces, a first connector for receiving goods from an external source, and a second connector for outputting said goods to an external collector. The external source may be a loading station or another trolley connected to a loading station; if a collector is connected, the collector is typically another trolley of the same type.

[0017] Preferably, the trolley is an autonomous guided vehicle (AGV).

[0018] The autonomy of the trolley can mean that, in its unloaded state, the trolley is suitable for identifying workstations that have completed or are about to complete processing steps associated with the workstation, so as to navigate to the workstation and load the workpiece onto the workstation after the processing steps have been completed.

[0019] Similarly, the trolley can be adapted to identify the next machining step to be performed on the workpiece during loading, identify the next workstation associated with the next method step, and drive the workpiece to the next workstation. The identification of the next machining step can be based on data loaded from the workstation by the trolley while it is docked to the workstation.

[0020] Preferably, the first connector and the second connector are located on opposite sides of the chassis, such that when the first connector on one side of the chassis faces the station to which the trolley is docked, the second connector on the opposite side can freely accommodate the second trolley. For effective docking, the side containing the first connector should be the front side of the trolley in its normal displacement direction, allowing for easy connection by approaching the loading station via the trolley in its normal displacement mode, and the second trolley can be moved in the same displacement mode to connect to the second connector located at the rear.

[0021] Preferably, the first connector and the second connector are hermaphroditic, so that when the trolley approaches the loading station, the trolley can contact the loading station through either of its connectors that is located at the front.

[0022] The trolley should include a storage device for goods that communicate with the first connector.

[0023] As described above, the storage space of the trolley can be a dustproof compartment. In this case, the goods should include compressed gas, and the trolley should include a device, in particular a valve, for metering the compressed gas entering the compartment. Therefore, even if the compartment is not airtight, dust can be prevented from entering the compartment because the air escaping through the gaps in the compartment will prevent dust from entering the compartment through these gaps or through at least one port.

[0024] In cases where the trolley includes a track section for movable support of the workpiece, the track section can be adapted to be connected to the track section of the same second trolley. In this way, the workpiece can be transferred from the second trolley to the first trolley and vice versa, without either trolley having to move and interrupt loading.

[0025] For the trolley, it is also advantageous to have multiple ports in order to minimize the amount of manipulation required to couple to the workstation ports. Preferably, two ports associated with the first and second connectors of the chassis are located on opposite sides of the dustproof compartment.

[0026] In order for the trolley to identify the next method step to be performed on the workpiece loaded onto it, and to identify the target workstation for the workpiece, each workpiece should have a schedule of the method steps to be performed on it, which the trolley can access.

[0027] To access the plan, the trolley may include a reader, such as an RFID reader, for reading and writing data from the workpiece's data carrier. The data may include the plan itself, or a reference to the plan retrieved from a database.

[0028] Each workstation may have an associated recording device for writing records of the workstation and / or its associated method steps into the schedule of the workpiece being processed by it, such that when the workpiece is loaded onto a trolley, the trolley can identify the next method step to be performed on the workpiece and find a suitable workstation to deliver the workpiece to.

[0029] For good maneuverability, the chassis may include multiple casters that are independently driveable and rotatable about a vertical axis. Attached Figure Description

[0030] Other features and advantages of the invention will become apparent from the following description of embodiments, with reference to the accompanying drawings.

[0031] Figure 1 This is a schematic diagram of a conventional production line;

[0032] Figure 2 This is a schematic diagram of the first production line according to the present invention;

[0033] Figure 3 This is a schematic diagram of the second production line according to the present invention;

[0034] Figure 4 This is a schematic diagram of the third production line according to the present invention;

[0035] Figure 5 Is Figure 2 , Figure 3 and Figure 4 A diagram of the trolleys used in the production line; and

[0036] Figure 6 This is a schematic cross-sectional view of the chassis of the trolley. Detailed Implementation

[0037] Figure 1This is a schematic diagram of a typical production line for painting car bodies. The production line workstations include painting stations 1-6. Painting station 1 is used to apply primer to the white car body, stations 2 and 3 are used to apply base coats to the interior and exterior of the car body, respectively, and stations 5 and 6 are used to apply clear coats to the interior and exterior.

[0038] While painting stations 1-3, 5, and 6 would be sufficient for painting a single color on a car body, additional painting stations are needed to meet customer desires for multi-colored bodies, such as a roof that differs from the rest of the body. Integrating this additional painting station into the linear path of the car body would increase processing time for all bodies and leave the additional painting station idle most of the time. Therefore, Figure 1 The production line provides track switches 7 and 8. If necessary, the car body can be sent to painting station 4 at track switch 7, while all other car bodies are sent directly to painting stations 5 and 6. In station 4, the paths of the car bodies that have already been painted and the paths of those that have not been painted converge again at track switch 8.

[0039] When a coat of paint has been applied, and before the next coat is applied, the car body undergoes flash evaporation; that is, the volatile components of that coat are allowed time to evaporate and are then baked. Therefore, Figure 1 The production line has a baking station 9 between painting stations 1 and 2, a baking station 10 between painting stations 3 and 4, a baking station 11 between track switch 8 and painting station 5, and a baking station 12 after painting station 6. A flash station 13 is provided between stations 1 and 9, stations 9 and 2, station 3 and track switch 7, and in other locations... Figure 1 Various other locations are shown.

[0040] Because of the presence of track switches 7 and 8, not all stations on the production line can be directly adjacent and sealed to each other. Wherever the tracks 14 used for transporting the car bodies extend beyond the workstations, they must be tightly covered to ensure that no dust accumulates on the car bodies during transport.

[0041] Figure 2 The diagram illustrates a production line according to the present invention. The workstations of this production line are... Figure 1 The processes are the same, and the steps of the painting process performed by them are also the same. Therefore, with Figure 1 The same reference numerals will be used for workstations, and their descriptions will not be repeated here.

[0042] like Figure 1As shown, there are three sets of adjacent workstations: the first set includes painting stations 1, 2, and 3 and baking station 9; the second set includes baking station 10 and painting station 4; and the third set includes painting stations 5 and 6 and baking stations 11 and 12. No tracks are provided between these sets. Instead, a flat floor surface exists between these sets, on which vehicles can move freely in two dimensions without being constrained by tracks.

[0043] Painting station 3 has an output port 15 for discharging the car body after the base coating has been applied to its exterior. A trolley 16 is shown coupled to the output port 15 for receiving the car body. Once the car body is loaded onto trolley 16, it is driven to the next station where it will be processed. In the case shown, this is baking station 11 or baking station 10. There is no flash drying station on the output side of painting station 3 because the time spent transporting the car body to the trolley is used for the flash drying stage.

[0044] The trolley 16 has an input port 17 and an output port 18. The input port 17 is used to couple to the output port 15 of the painting station 3. The output port 18 is opposite to the input port 17 and can be coupled to the input port 19 of the baking station 10 or 11 to unload the vehicle body.

[0045] Workstations 3 and 10 have ports 15 and 19 facing each other, allowing trolley 16 to move along a straight line 20 from one workstation to another, while movement from painting station 3 to baking station 11 involves a U-bend 21. Figure 2 In the U-bend 21, which is wider than required to reach workstation 11, at the end of the U-bend, the second image 16' of the trolley 16 is shown as a parking position laterally offset relative to input port 19, allowing another trolley 22 to complete unloading the car body into workstation 11 and then move away. This can occur because when the car body has already been processed in paint station 4, it and the next car body finished by paint station 3 will compete for a place in baking station 11. The use of the trolleys allows one (or more) car bodies to be held waiting to enter baking station 11 whenever needed.

[0046] Figure 3 The illustration shows a second embodiment of the production line, which is more advanced than... Figure 2 The production line more systematically utilizes the possibilities offered by the trolleys. Only one flash station 13 remains in this production line; all other flash stations are replaced by trolleys. Although in Figure 3 Only two trolleys, 16 and 22, are shown, but their number can be larger as needed, for example, as temporary storage for car bodies that must wait for the next processing step. The number of trolleys is less than... Figure 2The number of flash stations 13 is chosen because flashing requires less time than painting or baking. Therefore, by transporting the vehicle body between more than one pair of stations, one trolley can replace more than one flash station, thus saving space and cost.

[0047] Painting stations 1-6 and Figure 1 and Figure 2 The painting stations are identical and serve the same purpose. The necessary painting stations 1-3, 5, and 6 are located on one side of the central aisle 23, while optional painting stations 4 and baking stations 9-12 are on the other side. Once the primer has been applied to the car body in painting station 1, one of the trolleys 16 and 22 arrives and shuttles it through aisle 23 to baking station 9. Trolley 16 is shown transporting the car body from baking station 9 to painting station 2. Since painting stations 2 and 3 are arranged in a straight line, the trolley must remove the car body (where its base coating has been applied in stations 2 and 3) from the output port 15 of station 3, away from aisle 23, and transfer it from there to one of baking stations 11, or to baking station 10 if the car body is to be painted with more than one color.

[0048] Baking station 10, flash steaming station 13, and painting station 4 are arranged adjacent to each other, such that the car body delivered to the baking station can be conveyed to the painting station 4 without the use of a trolley. Trolley 22 is shown as removing the car body from the painting station 4 and delivering it to the baking station 11. Alternatively, it can be delivered back to the baking station 10. Thus, by sending the car body back through the painting station 4, many different colors can be applied to the car body parts as needed without additional investment in the required machinery.

[0049] The trolley 22 delivers its body to port 15 of the baking station 11, which is away from the passage 23, because the port from the painting station 4 is the fastest and easiest to reach. That is, each port 15, 19 of station 11 can be used as an input port or an output port as needed.

[0050] If baking station 11 is occupied while baking station 12 is not occupied when trolley 22 must deliver its body, trolley 22 is adapted to detect this fact and instead deliver to baking station 12.

[0051] When the car body, which had previously passed through painting stations 2 and 3 and finally through painting station 4, is removed from baking station 11, it is conveyed to painting station 5 by a trolley (not shown). It is then conveyed from the output port 15 of painting station 6 back to any of the currently idle baking stations 11 and 12.

[0052] After processing at this final baking station, the painting process is completed, and the car body is transferred to the subsequent assembly line.

[0053] Figure 4An embodiment of further optimized production line is illustrated. Here, all transport of the car body is accomplished by trolleys, from loading the white car body into painting station 1 to unloading the fully painted car body from one of the baking stations. The pairs of stations 2, 3 and 5, 6 used for painting the interior and exterior of the car body have been replaced by combined stations 2 / 3 and 5 / 6, each designed for painting the interior and exterior respectively. Since processing the car body in each of the combined stations 2 / 3 and 5 / 6 takes longer than in the single-function stations 2, 3 and 5, 6 of the aforementioned embodiment, more than one of each type is provided. Therefore, a processed car body can be unloaded from, for example, one of stations 2 / 3 and replaced by a new one, while the other is occupied to process a car body, and one trolley 16 or 22 is sufficient to serve both.

[0054] Painting stations 1, 2 / 3, and 5 / 6, and baking stations 9-12 are located on opposite sides of passageway 23. All are loaded and unloaded through ports facing passageway 23. Since it is no longer necessary to transfer the vehicle body through the workstations, the conveying devices for the workstations can be eliminated; this is sufficient if the trolley has a conveying device with an operating range adequate to properly place the vehicle body within workstations 1-6 and 9-12 and retrieve it from there.

[0055] At least some of the baking stations 9-12, such as stations 9 and 10, have a repositionable or independently controllable heater 24 with section 25 to locally apply heat to a portion of the car body that will receive another paint layer on top of the base coat in painting station 4. Therefore, when a car body is removed from one of stations 2 / 3 and is intended for painting station 4, the trolley must take it to one of stations 9, 10; otherwise, it can take it to any of the available or soon-to-be-available baking stations in baking stations 9-12. Similarly, a car body removed from station 4 or stations 5 / 6 can be baked in any of stations 9-12.

[0056] Figure 5 This is a schematic diagram of one of the trolleys (e.g., trolley 16). The trolley has a chassis 26 that supports a box-shaped compartment 27 for receiving the body 28 on the substructure 29.

[0057] The chassis 26 includes a rectangular base 30 with four casters 31 at its corners. Each caster 31 includes a wheel 32, a first electric motor 33 for driving the wheel 32, a second motor 34 for rotating the wheel 32, and an associated motor 33 about a vertical axis. The motors 33, 34 of the four casters 31 are independently controlled by an onboard computer 35, enabling the trolley to drive in curves, rotate on-site, or arbitrarily change its direction of movement while maintaining its orientation.

[0058] The chassis also carries a compressed air container 36 and a battery pack 38. The compressed air container 36 is used to pressurize the compartment 27 with clean air, and the battery pack 38 is used to power motors 33 and 34, a computer 35, and a solenoid valve 47, which controls the airflow from the container 36 to the compartment 27.

[0059] Computer 35 has a wireless interface 37 for communicating with other computers on the production line and with a transponder 39 attached to the vehicle body 28.

[0060] Compartment 27 is defined at its four corners by supports 40, a top 41 supported by the supports 40, and sidewalls extending between the supports 40 on the two longer sides of the base frame 30. On the two shorter sides, sliding doors serve as input and output ports 17, 18. The door panels are flexible or hinged, allowing the doors to be opened without protruding beyond the contours of compartment 27. For example, the door panels can be formed as roller blinds 42, guided in recesses in the supports 40 and raised and lowered by rotation of a sprocket 43 controlled by a computer 35. The left port 17 is shown in the open state, with most of the roller blind 42 extending along the top 41; the right port 18 is closed, with one end of the roller blind 42 contacting the base frame 30.

[0061] When trolley 16 is idle, computer 35 scans for wireless messages indicating that the vehicle is ready for transport or about to be transported to a workstation. The requester sending such a message can be the workstation itself or a central computer controlling the operation of the workstation. Upon receiving a message, trolley 16 calculates the distance or time required to reach the workstation and issues a bid indicating the result. Among several such bids, the requester selects the trolley with the shortest distance or time and sends a return message to trolley 16 indicating that its bid has been accepted. Trolley 16 then navigates to the indicated workstation and connects one of its ports 17 and 18 to a port on the workstation.

[0062] When the port facing the workstation and trolley is opened, the positive pressure in compartment 27, supported by air flowing from container 36 through valve 47, ensures that air is blown out through the gap between the ports, so that no dust can reach compartment 27 when the body 28 and substructure 29 are passed into compartment 27. After the body 28 has been received, port 17 is closed again.

[0063] The movement of the vehicle body 28 within the compartment 27 can be accomplished by a plurality of rollers 44, which are rotatably mounted in the upper surface of the underframe 30 to support the substructure 29. Some of the rollers may be motorized for active movement of the vehicle body.

[0064] Instructions regarding the destination of the vehicle body 28 can be provided directly by the central computer. Alternatively, the trolley's computer 35 retrieves an identifier from the transponder 39, which can be used to query the processing status of the vehicle body 28 from the central computer, or to retrieve the processing status of the vehicle body directly from its transponder 39.

[0065] The processing status identifies the painting processes to be applied to the vehicle body 28, their execution order, the workstations executing them, and, where appropriate, processing data such as the identifier of the color to be applied, the vehicle body area to be painted, etc. Whenever a specific step of the painting process has been executed, it is marked as complete in the processing status. Based on this processing status, the computer 35 identifies the next step to be executed and the workstations capable of executing that step. It then sends a request for the allocation of processing time slots to all of these. The workstations respond by transmitting their next available time slot, and the computer 35 selects the one requiring the least waiting time, sends a reply message reserving that time slot, and begins moving the vehicle body 28 to its reserved workstation. Simultaneously, air continuously flows from container 36 into compartment 27.

[0066] Docking with the workstation can be accomplished via port 17 or 18. For docking, each port of the trolley 16 has an associated mechanical coupler 45, such as a pivotable hook, which is adapted to engage with a mating hook 49 of the workstation via a form fit as the trolley 16 approaches the workstation, thereby preventing the trolley from moving relative to the workstation when transferring the vehicle body between the two. Figure 6 Couplers 45 and 49 for trolley 16 and workstation (e.g., 1) are shown, slightly offset laterally for ease of distinction. Additionally, an electrical connector 46 is provided, through which trunk power is transferred when trolley 16 is connected to workstation 1. Energy-intensive tasks of trolley 16, such as transferring the vehicle body, heating or cooling compartment 27 between workstation 1 and trolley 16, can be activated only when trolley 16 is thus connected to the power trunk 50. This reduces the load on battery 38, improving the productivity of trolley 16 by reducing the percentage of operation time spent charging battery 38. Therefore, the time spent by trolley 16 connected to a workstation can be used to recharge battery 38 via power line 58 extending through chassis 26. Since the electrical force transferred to battery 38 must be just sufficient to enable trolley 16 to operate until it reaches the next workstation with trunk connector 50, battery 38 can be small and lightweight. Not all of the aforementioned different types of workstations need to be equipped with this trunk connector, but in reality, most of them will be.

[0067] If desired, after the workstation has performed its associated machining steps on the car body, the electrical connector 46 can also be used to transfer data from the workstation to the computer 35 of the trolley 16, such as the machining status of the car body 28 carried by the trolley.

[0068] Similar to electrical connector 46, pneumatic connector 48 is provided adjacent to each port 17, 18 of trolley 16, such that container 36 is refilled whenever trolley 16 is connected to workstation 1 equipped with a matching pneumatic connector 51. Figure 6 As shown, the pneumatic connector 48 associated with port 17 includes an input port 52 and an output port 53. Input port 52 mates with connector 51 of workstation 1. An air duct 54 extending from input port 52 to container 36 within chassis 26 includes a check valve 55 that prevents air leakage from input port 52 when not connected. An air duct 56 extending between output port 53 and container 36 includes a valve 56 that opens only when output port 53 mates with some external input port. Since workstation 1 does not have such an input port, valve 56 associated with port 17 is closed.

[0069] On the side of chassis 26 located below port 18, there are identical components for the electrical connectors and pneumatic connectors 46, 48 of the connector facing the approaching trolley 22. This component is inverted symmetrical, allowing the components of port 18 to be connected to workstation 1 in the same manner as the components of port 17. As trolley 22 advances further toward trolley 16, their mechanical couplers 45 engage and lock with each other in the contact position of their electrical connectors 46, and the input and output ports 52, 53 of two trolleys 16, 22 engage. Although each input port is coupled only to the output port of the other trolley, and might therefore be considered a male / female coupling, the pneumatic connector 48 is bisexual overall.

[0070] In the docked state, the battery of trolley 22 can be recharged from the mains power supplied to it via the power line 58 of trolley 16. The valve 57 on the port 18 side of trolley 16 is opened due to the engagement of the output port 53 with the input port 52 of trolley 22, allowing the container 36 of trolley 22 to be refilled while trolley 22 waits for trolley 16 to complete its task at workstation 1.

[0071] When trolley 16 completes its task, trolley 22 can reverse to allow trolley 16 to move away and then dock at workstation 1 at its original position. In a preferred embodiment, and as... Figure 5As shown, the mechanical couplers 45 and connectors 46, 48 of the trolleys are mounted on a support 59, which is movable relative to their respective chassis 26 along the engagement direction of the connectors 46, 48. When docked to a workstation or another trolley, the support 59 is... Figure 5 The trolley 16 is in the forward position shown on the side of port 18. When the trolley 16 completes its task at workstation 1, it retracts the two supports 59 to the position shown on the side of port 18. Figure 5 In the retracted position shown on the side of port 17. Due to the casters 31, the trolley 15 can then leave its position in front of workstation 1 in a direction orthogonal to the engagement direction, that is, it can move out of the gap between the workstation and the trolley 22 without the cooperation of the trolley 22. In the case of several trolleys queuing in front of the same workstation, as mentioned above regarding the... Figure 2 The discussion of baking station 11 is particularly advantageous.

[0072] The task of the trolley can be simply to deliver the car body 28 to the workstation, or to remove it from the workstation after processing. In each case, a time-consuming docking process must be performed to ensure that the car body can be properly unloaded from or loaded into the trolley. This double docking is unavoidable if the trolley will be reused in a new task once it has released its payload at the workstation, and another trolley can remove it after processing at the workstation is complete. In this case, to minimize the idle time at the workstation, it may be necessary to provide two ports for the workstation, such that when the processing of the car body at the workstation is about to be completed, and a trolley that has transported the completed car body is docked to one port, and another trolley that transports a new car body to be processed can be docked to the other port. With the trolleys and production line of the present invention, it is more efficient to have the trolley wait at the workstation while the car body it carries is being processed, and to have the same trolley remove it again when processing is complete. Therefore, the time spent in the docking process is reduced by half, and because the time spent docking the trolley to the workstation is effectively utilized, the productivity of the trolley can be as high as or even higher than that of trolleys that sometimes have to abandon the production line for reloading. Furthermore, the high efficiency of the workstation, even with only a single port, is achieved when the car body is loaded onto the trolley carrying it after processing, significantly reducing the cost of the workstation. Figure Labels Workstations 1-6 (Painting Stations) 7-8 Track Switch Workstations 9-12 (Baking Stations) 13 Workstations (Flash Stations) 14 orbits 15 Output Ports 16 cars 17 Input Ports 18 Output Ports 19 Input Ports 20 straight lines 21 U-shaped bends 22 cars 23 channels 24 Heaters Section 25 26 Chassis 27 compartments 28 Body 29. Substructure 30 base frame 31 Casters 32 wheels 33, 34 Motors 35 Computers 36. Compression device 37 Wireless Interface 38 battery packs 39. Transponder 40 pillars 41 Top 42 Roller blinds 43 Sprockets 44 rollers 45 Mechanical Coupler 46 Electrical connectors 47. Solenoid valve 48 Pneumatic connector 49 hooks 50 power supply trunk line 51 Pneumatic Connector 52 Input Ports 53 Output Port 54 Air duct 55 Check valve 56 Air duct 57 valve 58 Power cord 59 Support components

Claims

1. A production line for processing a workpiece (28) in a continuous series of steps, the production line comprising a plurality of stations (1-6, 9-12) and a plurality of carriages (16, 22), each of the plurality of carriages (16, 22) comprising a first connector, Each trolley includes a motorized and maneuverable chassis (26), a storage space for workpieces, a first connector for receiving goods from an external source, and a second connector for outputting the goods to an external collector. The storage space is a dustproof compartment (27), the cargo includes compressed gas, and the trolleys (16, 22) include a device (47) for metering the compressed gas entering the dustproof compartment (27). The plurality of stations includes at least one workstation and at least one loading station, the at least one workstation being adapted to perform associated steps in the steps described above, and the at least one loading station including a second connector (50, 51) for supplying goods to one of the trolleys (16, 22) when connected to the first connector of one of the trolleys, characterized in that... At least one of the trolleys (16, 22) includes a second connector that communicates with the first connector.

2. The production line according to claim 1, wherein at least one of the workstations is also a loading station.

3. The production line according to claim 1 or 2, wherein the goods include one or more of electricity, data, fuel, compressed gas or vacuum.

4. The production line according to claim 1 or 2, wherein the second connector of the trolley (16, 22) is the same as the second connector (50, 51) of one of the loading stations.

5. The production line according to claim 1 or 2, wherein the dustproof compartment (27) has at least one port (17, 18) adapted to be coupled in a dustproof manner to a matching port (15, 19) of the at least one workstation.

6. The production line according to claim 5, wherein the port of the trolley (16, 22) and / or the port of the workstation includes a sliding door.

7. The production line according to claim 6, wherein the door comprises a flexible sheet (42).

8. The production line according to claim 1, wherein the trolleys (16, 22) are AGVs.

9. The production line according to claim 1 or 8, wherein the first connector and the second connector are located on opposite sides of the motorized and maneuverable chassis (26).

10. The production line according to claim 9, wherein the first connector is located on the front side of the motorized and maneuverable chassis (26) in the normal displacement direction, and the second connector is located on the rear side.

11. The production line according to any one of claims 1, 8 or 10, wherein the first connector of the trolley is adapted to be connected to the second connector of the same second trolley.

12. The production line according to claim 11, wherein the first connector and the second connector are bisexual.

13. The production line according to any one of claims 1, 8, 10 or 12, further comprising a storage device (36, 38) for communicating with the first connector for goods.

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