DEVICE AND METHOD FOR THE MANUFACTURING OF BIPOLAR PLATES

Abstract

Device for manufacturing bipolar plates for fuel cells, comprising a conveying device (2), a forming device (3) and a joining device (4), wherein the conveying device (2) automatically transports substrate plates (98) in a transport direction first to the forming device (3) and then to the joining device (4), wherein the forming device (3) imprints structures into the substrate plates by means of at least one embossing tool (31) or at least one forming tool and thereby transforms a substrate plate (98) into an anode plate (91) or a cathode plate (92), and wherein the joining device (4) joins an anode plate (91) and a cathode plate (92) to form a bipolar plate (93), characterized by that the conveying device (2) has a transport beam (21, 22) with at least one workpiece gripper (23) for gripping substrate plates (98) and / or anode plates (91) and / or cathode plates (92), wherein the transport beam (21, 22) extends from the forming device (3) to the joining device (4) and a conveying drive device is connected to the transport beam (21, 22) to automatically drive the workpiece gripper (23) and / or the transport beam (21, 22) in or against the transport direction, and to automatically drive the workpiece gripper (23) and / or the transport beam (21, 22) in a lifting direction and / or in a clamping direction.

Description

[0001] The invention relates to a device and a method for producing bipolar plates according to the features of the preamble of claim 1.

[0002] Bipolar plates are used in fuel cells. A fuel cell has an electrochemical cell as the power-generating unit, which consists of an anode, a membrane, and a cathode. At the anode, hydrogen reacts, releasing electrons. The resulting protons migrate from the anode to the cathode. At the cathode, the protons react with oxygen, absorbing electrons. Water is produced as a reaction product. To increase the voltage of a fuel cell, several electrochemical cells are connected in series. This means they are electrically connected to one another. Bipolar plates are arranged between the individual cells. They have an anode on one side and a cathode on the other. They separate the individual cells and conduct the generated current to the outside. Channels through which reaction media are fed are embossed in the bipolar plates.Hydrogen or a hydrogen-containing carrier medium is supplied to an anode. Oxygen or an oxygen-containing carrier medium is supplied to a cathode. The resulting reaction water is also removed through channels in the bipolar plates.

[0003] A corresponding device for producing bipolar plates is known from DE 10 2009 059 765 A1. The starting material consists of flat, strip-shaped sheets into which structures, i.e. channels, are introduced by forming. After forming, the individual plates are separated from the strips and subjected to a cleaning step. After cleaning, the individual plates are stacked on top of one another and joined to form a bipolar plate using a laser welding process. The joined plates are then cleaned again and sent to a coating system. In a coating system, a catalyst is vapor-deposited using a PVD process in a vacuum. This coating forms a reactive layer which, on the one hand, protects the plate and, on the other hand, improves its reactivity. After coating, the plate is cleaned again.Subsequently, several bipolar plates are combined to form a fuel cell stack. The disadvantage of this known process is that, due to the large number of processing steps, multiple machines and a correspondingly large area are required to manufacture the bipolar plates. Appropriate handling of the plates is necessary between the processing machines. Furthermore, due to the alternating chemical and mechanical processing steps, production is complex and requires extensive manual intervention.

[0004] DE 10 2004 050 921 A1 discloses another method for producing bipolar plates. This method involves several separate workstations. In a first workstation, a sheet metal strip is divided into individual plates by a punching process. The plates remain connected to form a sheet metal strip by the individual plates having small webs that connect them to the edge of the sheet metal strip. From processing station 1, the sheet metal strip is motor-driven to a second workstation, where a stamping process is carried out to create flow channels or connecting channels in the plates by shaping them. The connected sheet metal parts are then guided to a third station, where they are separated from the sheet metal strip. Following the third station, the plates are transported to a coating system.In the coating system, the individual plates are coated using a sputtering process. This process also requires several consecutive chemical and mechanical processing steps, which must be carried out at numerous individual workstations. The handling of the individual plates and the necessary cleaning between workstations makes this manufacturing process relatively complex and requires a lot of space.

[0005] DE 10 2014 101 899 A1 describes another process for manufacturing bipolar plates in a production line. In the abstractly described production line, several substrate strips in several layers are processed in parallel. The workpieces obtained through parallel processing are joined to form a bipolar plate in a final step. During processing, the production steps of punching, forming, coating, joining, and separating are carried out sequentially. Necessary cleaning steps to remove unwanted residues from the substrate strips, for example, between the forming and coating steps, are not described in this document, but must be performed to obtain a functional bipolar plate. This makes the described process relatively complex.

[0006] A method for producing bipolar plates is known from DE 10 2015 207 964 A1.

[0007] From JP 2013 152 941 A a method for producing bipolar plates by means of a rolling process is known.

[0008] From DE 10 2010 056 016 A1, another method for producing bipolar plates is known, wherein at the end of the processing, fuel cell stacks are produced using a stacking tool.

[0009] The object of the present invention is to create a device and a method for producing bipolar plates that enables cost-effective production and requires as little space as possible. In particular, the process should be automated to the greatest extent possible. In particular, the necessary manual work steps should be reduced.

[0010] This object is achieved according to the invention by a device for producing bipolar plates for fuel cells having the features of claim 1, as well as by a device for producing bipolar plates for fuel cells having the features of claim 11, and by a method for producing bipolar plates for fuel cells having the features of claim 27. The method according to the invention is carried out using a device according to the invention.

[0011] According to the invention, the device for producing bipolar plates comprises a conveyor device for automatically transporting individual plates in a transport direction, wherein the conveyor device has a transport beam with at least one workpiece gripper for gripping substrate plates and / or anode plates and / or cathode plates, wherein the transport beam extends from the forming device to the joining device and a conveyor drive device is connected to the transport beam in order to automatically move the workpiece gripper and / or the transport beam in or against the transport direction, and to automatically move the workpiece gripper and / or the transport beam in a lifting direction and / or in a clamping direction. The conveyor device enables automated transport of both substrate plates and anode plates and cathode plates across multiple workstations.The automatic drive of the transport beam in at least two, preferably three, directions enables automatic handling of the substrate plates without the need for manual intervention. This makes it possible to perform several work steps directly one after the other without requiring manual intervention in between. This makes it possible to build compact manufacturing devices that require little space, as well as to produce the bipolar plates fully automatically, and especially at high speed.

[0012] In one embodiment, the device for producing bipolar plates for fuel cells comprises a conveying device, a forming device, and a joining device, wherein the conveying device transports either substrate material, preferably strip-shaped substrate material, or individual substrate plates or a plurality of interconnected substrate plates, preferably substrate plates connected to form a strip, automatically driven in a transport direction first to the forming device and then to the joining device, wherein the forming device embosses structures into the substrate plates by means of at least one embossing tool or at least one forming tool, and thereby forms a substrate plate into an anode plate or a cathode plate. Preferably, together with the forming of the plates, a separation of a substrate plate or a partial separation of a substrate plate can also take place.The joining device then joins an anode plate and a cathode plate to form a bipolar plate. Advantageously, a bipolar plate with an anode plate and a cathode plate can be produced from a single substrate material. The device therefore preferably comprises a substrate magazine that holds a single coil of substrate material and feeds it to the device.

[0013] Preferably, the conveying device comprises one or more controlled electric motors connected to a control device to enable precise and automatic conveying of individual substrate plates.

[0014] Flat, planar substrates can be used as substrate plates or as substrate material, which can be supplied, for example, as roll material on a reel or as strip material. In particular, substrate material refers to a coated carrier material. This substrate material can be used as a strip wound on rolls or reels. Individual substrate plates can be separated from the substrate material, which can be, for example, a roll material or strip material. Flat, strip-shaped sheets, preferably stainless steel sheets or conductive, in particular carbonized, plastics, can be used as roll material or strip material, for example. A coating is preferably applied to the roll material or strip material serving as the substrate. It is advantageous if a plate already provided with a reactive coating and / or catalyst coating is used as the substrate plate.The coating processing step, which is usually required after forming the substrate, can then be eliminated with the method according to the invention. Likewise, the cleaning of the substrate plates required before coating can be eliminated. Drying of the substrate plates, which is normally required after coating, can also be eliminated.

[0015] To separate a substrate plate, a separating device can be provided in a transfer area between the substrate belt and the conveyor device, which separates individual substrate plates from the substrate belt. The separating device can be, for example, a pair of scissors, a laser cutter, a waterjet cutter, or a punching device.

[0016] In one embodiment, the substrate plates can be completely separated from the substrate strip by the separating device and transported individually. In another embodiment, the substrate plates can be separated by the separating device in such a way that the substrate plates are further connected to the substrate strip by means of residual webs and are transported further as a continuous strip. Preferably, the separating device can either be designed separately or integrated into a forming tool, for example the anode tool or cathode tool. In particular, the forming of a substrate plate into an anode plate or cathode plate can take place in one work step at the same time as the complete or partial separation of a plate from the substrate material.

[0017] The conveyor device can comprise a roller conveyor device or an eddy current conveyor device for transporting substrate material, such as roll material or strip material. Furthermore, the conveyor device can comprise a roller conveyor device or an eddy current conveyor device for transporting substrate plates and / or anode plates and / or cathode plates.

[0018] A roller transport device comprises a driven roller that interacts with the strip material or plate (substrate plate and / or anode plate and / or cathode plate) to transport it. Two rollers can also be provided, between which the substrate material or plates to be transported are guided.

[0019] An eddy current transport device is particularly used for relatively thin strip material or thin plates. The transport of the substrate material or plates is achieved through the interaction of eddy currents induced in the substrate material or plates (substrate plate and / or anode plate and / or cathode plate) and a magnetic field.

[0020] The structures embossed into the substrate plates by the forming device form channels and / or openings in the bipolar plate through which reaction media, i.e., hydrogen-carrying media or oxygen-carrying media, can be conducted. Furthermore, the structures can form channels that allow the resulting reaction product, in particular water, to be removed from the bipolar plate. Furthermore, the structures can comprise channels for conducting a cooling medium or heating medium through the bipolar plate. This makes it possible to maintain the finished fuel cell at a specific operating temperature. For example, the forming and / or embossing of the substrate plates can be carried out in a press device or a roller device.

[0021] In a preferred embodiment, the transport beam of the conveyor device can be made of a profile material, such as a metal profile that can be cut to length. The transport beam can also serve as a transport rail. It has a supporting function and transports the individual plates held by the workpiece grippers, i.e. a substrate plate and / or an anode plate and / or a cathode plate. The workpiece grippers are designed as controllable grippers for the individual plates. I.e. the workpiece grippers are designed to grip a substrate plate as well as an anode plate and a cathode plate. For example, the workpiece grippers can pick up the individual plates mechanically, preferably via controlled claws. Alternatively, it is also possible for the workpiece grippers to pick up, i.e. hold, individual plates using negative pressure.It is also conceivable that the workpiece grippers pick up or hold the individual plates magnetically, in particular via a controlled electromagnet.

[0022] In one embodiment according to the invention, the forming device comprises one or more stamping tools. As a first stamping tool or forming tool, the forming device can comprise one or more anode tools for forming anode plates. Spaced apart in the transport direction from this, the forming device can comprise, as a further stamping tool or forming tool, one or more cathode tools for forming cathode plates. In particular, it is provided that the multiple anode tools are arranged directly one behind the other. Accordingly, preferably, multiple cathode tools are also arranged directly one behind the other.This arrangement enables short paths and thus short transport times for the plates between the individual forming stations, even in a multi-stage forming process, since the processing of an anode plate takes place in tools arranged directly one behind the other, and the processing of a cathode plate also takes place in tools arranged directly behind the other. The joining device is located between an anode tool and a cathode tool, thus centrally positioned, so to speak.

[0023] The conveyor device conveys the anode plates and cathode plates in opposite directions, viewed in the transport direction, and transports one anode plate and one cathode plate at a time to the joining device. The arrangement of the joining device between an anode tool and a cathode tool results in an advantageous reduction in the required installation space, since this production line can be fed with raw material, i.e., substrate plates, from both ends.

[0024] For example, in a configuration with substrate feed from both sides, the device comprises a substrate magazine, particularly at each end, which holds a single reel or coil of substrate material and feeds it to the device. This means that the substrate material is fed to the device from two sides and conveyed in opposite directions.

[0025] An advantage is that the substrate material can be transported in a single layer. Regardless of whether the substrate material is fed from one side or from both sides, the substrate material is conveyed in a single layer. This simplifies handling of the substrate material and reduces the space required for the device according to the invention compared to devices in which the substrate is conveyed in multiple layers.

[0026] An advantageous basic idea of ​​the invention is that in the production of bipolar plates for fuel cells, a bipolar plate is formed by joining an anode plate to a cathode plate, and before joining, an anode plate and a cathode plate are formed from a substrate plate by forming or embossing structures. According to the invention, a plate already provided with a reactive coating and / or catalyst coating is used as the substrate plate, and the method is carried out using a device according to the invention. This makes it possible to produce the bipolar plates without alternating mechanical

[0027] Processing steps and chemical processing steps must be performed. The number of necessary processing steps is significantly reduced, and complex cleaning processes between individual work steps can be eliminated.

[0028] Preferably, the forming and / or embossing of the substrate plates is carried out in a press device or a roller device. The press device can be designed as a vertical press or a horizontal press. In particular, the forming device can be designed as part of a press device.

[0029] In an exemplary embodiment, the press device can have vertical press stands and a press table, with the transport beam running parallel to a long side of the press table. For example, it can be provided that the forming device is designed as part of a press device, wherein the press device has vertical press stands and a press table arranged between the press stands, and the transport beam runs parallel to a long side of the press table. To achieve a compact design, the press stands can be connected to one another, for example, by a press yoke. Press rams and the drives for the press rams are arranged on the press yoke.

[0030] In one embodiment, it can be provided that the press device has a first press ram that interacts with an anode tool and a second press ram that interacts with a cathode tool. For example, the anode tool can be designed in two parts, with a first part of the anode tool being arranged on the press table and the second part of the anode tool being connected to a press ram. A substrate plate is arranged between the two tool parts by the conveying device and the two tool parts are pressed together via the press ram, thereby forming the substrate plate. The cathode tool is constructed analogously. The anode tool can be designed separately from the cathode tool. This means that the press has two different press rams, with one press ram being connected to the anode tool and another press ram being connected to the cathode tool.

[0031] In an alternative embodiment, a press die can be connected to both an anode tool and a cathode tool, so that two substrate plates are processed in a single forming step and thus an anode plate and a cathode plate are formed simultaneously.

[0032] In particular, it is provided that after forming or embossing, an anode plate and a cathode plate are automatically transported to a joining device and joined there to form a bipolar plate. In this case, it can be provided that, in order to join the bipolar plate, a cathode plate is placed on an anode plate by means of the conveying device in the region of the joining device, or an anode plate is placed on a cathode plate by the conveying device first placing a cathode plate or an anode plate into a holder of the joining device and then the conveying device moves an anode plate or a cathode plate at least partially overlapping the inserted cathode plate or anode plate and then placing it on the inserted cathode plate or anode plate.

[0033] The advantage here is that, particularly after the forming or embossing step, the anode plate and / or the cathode plate are not coated with a reactive coating or a catalyst coating. Preferably, even after the step of joining an anode plate to a cathode plate to form a bipolar plate, it is not necessary to coat the bipolar plate with a reactive coating or a catalyst coating. This is achieved by using a substrate material that is already coated. A suitable coating has high corrosion resistance and / or high electrical conductivity. The coating can, for example, contain one or more of the following materials: gold, platinum, silver, titanium carbides or titanium nitrides, Ti3SiC2, chromium, carbon or nickel. The function of the electrode of an anode plate orCathode plate is preferably supported by the reactive coating or the catalyst coating of the substrate plates.

[0034] Alternatively, a substrate material can be used that does not require a coating.

[0035] In one embodiment, it can be provided in particular that the conveying device has at least two transport beams running parallel to one another in the transport direction, wherein each transport beam has at least one workpiece gripper for gripping substrate plates and / or anode plates and / or cathode plates. If the conveying device has a single transport beam or transport rail running in the transport direction, substrate plates and / or anode plates and / or cathode plates can be transported in a row using this. If the plates have larger dimensions, it can be advantageous if the conveying device has two transport beams or transport rails running parallel to one another. The workpiece grippers of these two transport beams can then grip the plates from both sides in order to prevent them from deforming during transport.Alternatively, each of the transport beams or transport rails can grip a separate plate in order to form two parallel production lines with a single conveyor device.

[0036] In one embodiment, it can be provided that the transport beam is mounted on or at a locking box, wherein the locking box has a lifting drive to drive the transport beam in a lifting direction and / or a clamping drive to drive the transport beam in a clamping direction and / or a longitudinal drive to drive the transport beam in the transport direction. The locking box can, for example, have a supporting frame on which a lifting drive and / or a clamping drive is held. The lifting drive and / or the clamping drive can comprise a servo motor and / or stepper motor, or comprise several servo motors and / or stepper motors to drive the transport beam. In this context, lifting direction means that the transport beam is driven in the vertical direction, i.e. upwards and / or downwards.Transport direction means that the transport beam is driven in the transport direction or against the transport direction. The transport direction is essentially horizontal. Clamping direction in this context means that the transport beam is driven horizontally perpendicular to the transport direction. The clamping direction encompasses both directions. In the case of two parallel transport beams, transport in the clamping direction means that the two transport beams are moved toward each other. Transporting in the opposite direction to the clamping direction means that the two transport beams are moved away from each other.

[0037] In an alternative embodiment, the conveying device for driving the transport beams in the lifting and / or clamping direction can be designed such that the transport beam is mounted on a vertical press stand in the region of its ends via a lifting carriage driven by a lifting drive for vertical displacement. The lifting carriage rotatably supports one end of a rocker arm, the other end of which is connected to the support beam. In this case, the lifting movement of the transport beams is achieved by moving the lifting carriages in the vertical direction via lifting drives in the press stands.A clamping movement of the transport beams can be achieved by the lifting carriages controlling the rocker arm via a rotary drive. The lifting drive and the rotary drive are simultaneously controlled in such a way that the transport beam is moved horizontally by the rotary drive, while the vertical movement of the transport beam caused by the rotary movement is simultaneously compensated by the lifting drive. This allows a clamping movement to be performed without the transport beam being moved vertically.

[0038] For flexible construction and / or easy maintenance, the workpiece grippers can be removably mounted on the transport beam or a carriage of the transport beam.

[0039] To enable flexible control, one embodiment can provide for at least two movable transport carriages to be mounted on a transport beam, each of these two transport carriages holding a workpiece gripper and having its own drive device to move this transport carriage independently of other transport carriages along the transport beam. The panels can be transported on the transport beam both in the transport direction and against the transport direction via the individually driven transport carriages. This means that the panels can be transported in or against the transport direction independently of a longitudinal drive of the transport beam. This makes it possible, in one embodiment, to omit a drive for the transport beam in the transport direction, for example to make the device more cost-effective.In an alternative design, both the transport beam and the transport carriages mounted on the transport beam can be driven in the transport direction. This allows for significantly increased speed when transporting individual panels and greater flexibility in their control.

[0040] By individually controlling individual transport carriages, the transport device can transport individual plates at the same time, each with its own movement profile. A movement profile can include different parameters, such as speeds and / or accelerations and / or time-dependent speed changes and / or times or transport times and / or dwell times and / or stroke lengths and / or transport distances. This makes it possible for one and the same conveyor device to transport substrate plates, anode plates, and cathode plates through different workstations simultaneously on one and the same transport beam. The individual control makes it possible to meet the individual processing requirements of the individual workstations using one and the same transport beam.This allows both the dwell time in the forming device and the dwell time in the joining device to be individually controlled. This allows, for example, an anode plate to remain stationary in the anode tool while a substrate plate is already being transported toward the anode tool. Furthermore, the individual control of individual transport carriages allows, for example, an anode plate and a cathode plate to be transported toward each other in opposite directions.

[0041] In one embodiment, it can be provided that a workpiece gripper is mounted on a transport carriage so as to be driven and movable in the lifting direction, in that the transport carriage has a vertical drive for raising and / or lowering the workpiece gripper. The transport carriage has a vertical drive which can comprise a server motor and / or a stepper motor and / or a linear drive in order to raise or lower the workpiece gripper. This drive of the workpiece gripper can be supplementary to a lifting drive of the transport carriage. This offers the advantage that the plates with different vertical heights, i.e. in several levels with a horizontal distance from one another, can be transported on one and the same transport beam. This makes it possible, for example, for an anode plate and a cathode plate to be stacked on top of one another in the joining device.

[0042] For example, in one embodiment it can be provided that the conveyor control device controls the conveyor device with such a movement profile that the conveyor device places a cathode plate on an anode plate in the area of ​​the joining device or places an anode plate on a cathode plate by controlling the transport bar and / or a workpiece gripper in such a way that it first places a cathode plate or an anode plate in a holder of the joining device and then an anode plate or a cathode plate is lifted in the lifting direction by the transport bar and / or a further workpiece gripper, moved at least partially in overlap with the inserted cathode plate or anode plate and positioned on the inserted cathode plate or anode plate by lowering the transport bar and / or the further workpiece gripper.

[0043] To provide flexible control of the conveyor device, the conveyor device can have a conveyor control device or be connected to a conveyor control device, wherein the conveyor control device controls the transport beam and / or a workpiece gripper. In particular, the conveyor control device can define a movement profile of the transport beam and / or a workpiece gripper. The conveyor control device can, for example, be integrated into a press control system or be designed as a separate conveyor control device. In particular, the conveyor control device can control the conveyor device from a central machine location by providing a digital bus system, in particular a CAN bus or a field bus, between the conveyor control device and the conveyor device.

[0044] Furthermore, it can be provided that the drive device of the transport carriage is connected to a carriage control device and the carriage control device is designed to control an individual transport carriage and / or an individual workpiece gripper, preferably that the carriage control device is connected to the conveyor control device or is integrated therein.

[0045] In order to enable counter-rotating transport of the plates in one embodiment, it can be provided that the conveying device has two conveyor belts, each guided over two deflection rollers and driven in counter-rotation, one of the conveyor belts transporting the anode plates and the other of the conveyor belts transporting the cathode plates.

[0046] In an alternative embodiment, it can be provided that a counter-directional transport of the plates is realized in that the conveyor device has a transport beam with at least one tool gripper for gripping substrate plates and / or anode plates and / or cathode plates, wherein the transport beam extends from the anode tool to the cathode tool and has a conveyor drive in order to automatically move the transport beam and / or the workpiece gripper in or against the transport direction, and to automatically move the workpiece gripper and / or the transport beam in a lifting direction and / or in a clamping direction. Counter-directional transport with only one driven tool gripper or only one driven transport beam can be realized in that one plate is first transported in the transport direction and then a second plate is transported against the transport direction.

[0047] The anode plate can be joined to the cathode plate using a welding device, in particular a laser welding device, an electrode welding device, or a plasma welding device. Mechanical joining, for example, by folding, can also be provided.

[0048] Joining the anode plate to the cathode plate can be performed as a complete joining process. This means that the joining device creates all the necessary connections between the anode plate and the cathode plate. Alternatively, the joining device can only create some of the necessary connections between the anode plate and the cathode plate, thus partially joining the plates. The remaining connections can then be made in a later work step, for example, together with the stacking of the bipolar plates.

[0049] In order to form bipolar stacks or fuel cell stacks from the manufactured individual bipolar plates, it can be provided that the joining device transfers a bipolar plate to a further transport device, which conveys the bipolar plate transversely to the transport direction and feeds it to a stacking device. A base part and a cover part as well as membranes and bipolar plates are fed to the stacking device. The stacking device first provides a fuel cell stack with a base part and alternately stacks bipolar plates and membranes on this. Finally, the stacking device provides the fuel cell stack with a cover part and screwed this to the base plate. The finished bipolar plate stack or fuel cell stack can then be removed from the stacking device. A membrane is preferably understood to mean a membrane made of a material that serves as an electrolyte membrane.

[0050] It is particularly advantageous that in the manufacturing method according to the invention or in the device according to the invention, no manual handling step is required between the supply of the substrate material and the removal of the finished bipolar plate stack or fuel cell stack, but that the handling of the bipolar plates, starting from the substrate material up to the bipolar plate stack, is fully automated.

[0051] In one embodiment, the further transport of the bipolar plates to the joining device can be provided by providing that the further transport device has a transverse conveyor belt that is guided circumferentially over two deflection rollers. Alternatively, the further transport device can also have a driven conveyor arm with a workpiece gripper. For example, the conveyor arm can be designed as a robot arm with multiple driven axes.

[0052] In order to increase production throughput, one embodiment can provide for the stacking device to alternately stack a bipolar plate and a membrane onto a fuel cell stack and simultaneously form two fuel cell stacks, in that the stacking device has a switch to feed a bipolar plate either to a first fuel cell stack or to a second fuel cell stack. The stacking device can form the fuel cell stacks one after the other by first filling one stack with bipolar plates before subsequently filling the second stack with bipolar plates. This makes it possible to remove a finished stack and prepare a new stack by inserting a base plate while the other stack is being built. Alternatively, the stacking device can fill both stacks with bipolar plates synchronously.

[0053] It has been shown that the required space can be reduced by arranging the switch to the side of the conveyor at the level of the joining device.

[0054] The switch can, for example, comprise a conveyor belt whose transport direction is controllable. For example, to feed a bipolar plate to the first bipolar plate stack, a first transport direction of the conveyor belt can be switched on. To feed a bipolar plate to the second bipolar plate stack, the second, opposite transport direction of the conveyor belt can be switched on.

[0055] In an alternative embodiment, the switch can also have a linear slide. The linear slide grips a bipolar plate via a corresponding gripper, lifts it, and transports it in a first direction to feed it to the first bipolar plate stack and deposit it there. To feed a bipolar plate to the second bipolar plate stack, the linear slide transports the bipolar plate in the opposite second direction and deposits the bipolar plate on the second stack.

[0056] A further improved use of installation space is achieved by providing, in one embodiment, that the first bipolar plate stack or fuel cell stack is arranged laterally next to the conveying device at the level of the anode tool and the second bipolar plate stack or fuel cell stack is arranged laterally next to the conveying device at the level of the cathode tool.

[0057] A further increase in productivity can be achieved by providing, in one embodiment, that two roll magazines with substrate rolls are arranged upstream and downstream of the conveyor device in the transport direction, with the first roll magazine delivering substrate strip in the transport direction to the conveyor device, and the second roll magazine delivering substrate strip against the transport direction to the conveyor device. Preferably, the substrate strips are designed as metal strips having a reactive coating and / or a catalyst coating.

[0058] The device according to the invention is particularly suitable for use in the production of fuel cells for the automotive industry. Advantageously, the device according to the invention can also be used in the production of fuel cells for combined heat and power plants, such as those required to supply individual buildings. It is intended that the method according to the invention be carried out using the device according to the invention.

[0059] The figures and the following description of the figures describe exemplary embodiments of the invention. They show: Fig. 1: a first embodiment of the invention with substrate feed on both sides; Fig. 2: a second embodiment of the invention with a one-sided substrate feed; Fig. 3: another embodiment of the invention with substrate feed on both sides; Fig. 4: an example of a forming device for the production of bipolar plates; Fig. 5: a detailed enlargement from Fig. 4 in the area of ​​a press stand; Fig. 6: an embodiment of a substrate magazine; Fig. 7: another embodiment of the invention with substrate feed on both sides.

[0060] The Fig. Figures 1 to 7 show different embodiments of the device according to the invention for producing bipolar plates for fuel cells. The designs of the individual embodiments are essentially identical. Differences between the individual embodiments are specifically noted in the description of the figures. Identical components are provided with the same reference symbols.

[0061] In the Fig. Figure 1 shows a first embodiment of the device 1 according to the invention for producing bipolar plates. The device 1 comprises a conveyor device 2, a forming device 3, and a joining device 4. The conveyor device 2 automatically conveys substrate plates 98 in or against the transport direction indicated by arrows. The substrate plates 98 are separated from a substrate belt 97 by a separating device 41. The substrate belt 97 is delivered in the form of roll magazines or reels 96 and fed from both sides of the device 1 for producing bipolar plates.

[0062] A press device 5 is a centrally located element of the device 1 for producing bipolar plates for fuel cells. The joining device 4, the conveying device 2, and the forming device 3 are mounted on the press device 5. Optionally, the separating device 41 for separating individual substrate plates 98 from substrate strips 97 is also arranged on the press device 5. The press device 5 has a press table 51, which is laterally bounded by four vertically arranged press stands 52a, 52b, 52c, 52d. The vertical press stands 52a-d stand on a press base at the bottom and are connected to one another at their upper portion by a press yoke. The press yoke supports the press rams of the press device 5.

[0063] The forming device 3 has stamping tools 31, in particular an anode tool 31a and a cathode tool 31b. Both the anode tool 31a and the cathode tool 31b are each connected to a press ram. The tools are divided into two parts, with a first part being connected to the press ram and a second part of the stamping tool being arranged on the press table. To form a substrate plate into an anode plate, the plate is transported by the conveyor device 2 to the anode tool. Subsequently, a forming process is carried out by means of the press device 5 or the anode tool 31a in order to form the substrate plate 98 into an anode plate 91. During this forming process, structures are stamped into the plate, which serve as channels for the supply and discharge of reaction media and also increase the mechanical strength of the anode plate. The anode tool 31a is arranged on the Fig. 1 upper side of the press device. The cathode tool 31b is in the area of ​​the Fig. 1 is arranged on the underside of the press system. Accordingly, the substrate plate 98 is formed into a cathode plate 92 via the cathode tool 31b.

[0064] The forming process of a substrate plate 98 into an anode plate 91 or a cathode plate 92 can, as described above, take place in one step. Alternatively, the forming process can also be carried out in several stages, in particular three stages. The conveyor device 2 conveys the plates 98 from one forming step to the subsequent forming step. In a first step, the substrate plate 98 can be cut from a substrate strip 97. Simultaneously with the cutting, passages or holes can be punched into the substrate plate. In a second step, the substrate plate can be preformed, for example by embossing first structures or channels into the substrate plate 98. In a third forming process, the surface of the substrate plate 98 can be calibrated to produce the final anode plate 91 or cathode plate 92.It is intended that the respective forming tool be constructed in several parts, corresponding to the number of stages. Thus, the anode tool 31a and / or cathode tool 31b can be divided into three parts, corresponding to the three consecutive forming steps.

[0065] The formed substrate plates, ie the anode plate 91 and the cathode plate 92, are transported in opposite directions to each other by the conveyor device 2. In the Fig. 1 the transport paths of the individual plates are shown by curved lines.

[0066] The joining device 4 is located approximately in the middle area of ​​the press. The anode plate supplied from one side is transported by the conveyor 2 into the area of ​​the joining device 4. Likewise, the cathode plate 92, transported in the opposite direction, i.e., from the other side of the press by the conveyor, is transported into the area of ​​the joining device 4 and there overlapped with the anode plate 91. The joining device 4 welds the anode plate 91 to the cathode plate 92 to form a bipolar plate 93.

[0067] The finished bipolar plate 93 is discharged laterally from the press device 5 (as in Fig. 1 by arrow) and transported to a switch 61. The switch 61 is designed as a cross conveyor belt 62 and transports the bipolar plate 93 either to the Fig. 1 or to the lower stacking device 6. The stacking device 6 comprises a feed device for a cover plate 95d as well as a feed device for a base plate 95b and a feed device for a membrane 94.

[0068] In the stacking device 6, a fuel cell stack 95 is formed as follows: First, a base plate 95b is used as the basis for the fuel cell stack. Bipolar plates 93 and membranes 94 are stacked alternately on top of this. Finally, the stacking device 6 stacks a cover plate 95d on top of the stack and connects the base plate 95b to the cover plate 95d, for example, using screws. The finished fuel cell stack 95 is transported away from the stacking device 6 in the direction of the arrow and can be removed from the removal station as a finished fuel cell stack 95.

[0069] The stacking device 6 is arranged laterally directly adjacent to the press device 5. This allows a spatially compact design of the device 1 for producing bipolar plates for fuel cells. It is also advantageous if the feed devices of the stacking device 6 are arranged one behind the other in the longitudinal direction in order to, as shown in the Fig. 1, to adapt to the longitudinal extent of the press device 5. In order to increase the output of the device 1 for producing bipolar plates, as shown in Fig. As shown in Figure 1, a press device 5 supplies two stacking devices. The finished bipolar plates 93 are alternately fed to the first stacking device and the second stacking device 6 via the switch 61.

[0070] The conveying device 2 comprises a first transport beam 21 and a second transport beam 22. The transport beams run parallel in the transport direction and at a distance from one another. They are arranged within the press device 5 and extend in the longitudinal direction essentially over the entire longitudinal extent of the press device 5. This means that both the first transport beam 21 and the second transport beam 22 extend essentially from the entrance gate of the press device 5, formed by the vertical press stands 52a and 52b, to the exit gate of the press stands 5, formed by the vertical press stands 52c and 52d. The transport beams 21 and 22 are each mounted on a locking box 53 in the region of their two ends. The locking box 53 has a lifting drive in order to be able to raise and lower the transport beams 21 and 22 in the vertical direction.Furthermore, the locking box 53 has a clamping drive in order to move the transport beams 21 and 22 in the clamping direction, i.e. in the horizontal direction towards one another or away from one another. The locking box 53 can also have a longitudinal drive in order to move one transport beam 21 or both transport beams 21 and 22 in the transport direction. A plurality of workpiece grippers 23 are arranged on each of the transport beams 21 and 22. The workpiece grippers 23 serve to grip and hold the plates, i.e. the substrate plates 98 as well as the anode plates 91 and the cathode plates 92 and the bipolar plates 93. The workpiece grippers 93 can be controlled individually, i.e. a control device can be used to control whether a specific workpiece gripper grips or puts down a plate. The workpiece grippers 23 are connected to the transport carriages 24 (as shown, for example, in FIG. Fig. 4) are removably mounted on the transport beams 21 and 22. This means that the workpiece grippers 23 can be replaced, for example, during maintenance or a conversion of the device 1 for producing bipolar plates.

[0071] Each transport carriage with its attached workpiece gripper 23 can be individually controlled via a control device. This means that a transport carriage 24 has a drive to move the transport carriage in the transport direction or counter to the transport direction along the transport beam 21 or 22. By individually controlling each transport carriage, it is possible to transport each individual panel located in the press device 5 according to a unique motion profile. This motion profile includes, for example, speeds and / or accelerations and / or dwell times and / or processing times.

[0072] In the Fig. 2 shows a variant of the device 1 for producing bipolar plates for fuel cells. In contrast to the device shown in Fig. The device 1 shown in Figure 1 is shown in Fig. 2, the press device 5 is only loaded with substrate strip 97 from one side. This means that the press device 5 has only a roll magazine 96 with substrate rolls to supply substrate plates 98. The press device 5 has, arranged one behind the other in the transport direction, a separating device 41 for separating individual substrate plates 98 from the substrate strip 97 and embossing tools. The anode tool 31a serves as an embossing tool after the separating device 41. The cathode tool 31b follows the anode tool in the transport direction. In the end region of the press device 5, the joining device 4 is arranged to weld an anode plate 91 to a cathode plate 92. The joining device 4 can comprise a laser welding device and / or a resistance welding device. The joined bipolar plates 93 are discharged from the press device in the transport direction and, analogously to Fig. 1, fed to a stacking device.

[0073] In contrast to the Fig. In the device 1 shown in Figure 1, the transport of anode plates and cathode plates takes place simultaneously in the transport direction. Anode plates 91 and cathode plates 92 are arranged alternately in a row one behind the other. In order to join an anode plate 91 to a cathode plate 92, the conveyor device 2 alternately conveys an anode plate 91 and a cathode plate 92 to the joining device 4, as can be seen from the illustration of the transport lines in Figure 1. Fig. 2 can be removed.

[0074] In the Fig. 3 shows a further embodiment of the device 1 for producing bipolar plates. In contrast to the previously illustrated embodiments, the conveyor device 2 in this embodiment comprises two counter-rotating conveyor belts 96a and 96b, which transport the plates, ie the substrate plates 98 and also the anode plates 91 and cathode plates 92. As in the Fig. 1, the press system 5 is also fed with substrate material 97 from both sides by means of two roll magazines 96. The Fig. 3 The conveyor belt 96a shown in the upper area transports substrate plates 98 or anode plates 91 in the transport direction to the joining device 3. The Fig. 3 The conveyor belt 96b shown in the lower area transports substrate plates 98 and cathode plates 92 against the transport direction to the joining device 4. The joining device 4 again connects an anode plate 91 with a cathode plate 92 to form a bipolar plate 93. The bipolar plate 93 is laterally, as in the Fig. 3 by the arrow direction, to a switch 61, which serves two stacking devices 6. The stacking devices are constructed and arranged in the same way as in the Fig. 1 shown embodiment.

[0075] In the Fig. 7 shows a further embodiment of the device 1 for producing bipolar plates. Here, too, the substrate material 97 is fed in from both sides, i.e. from opposite sides. The anode plates 91 and cathode plates 92 are also conveyed in opposite directions. This embodiment largely corresponds to the embodiments described above. In contrast to the previously described embodiments, the conveyor device 2 has a roller transport device for conveying the substrate strip 97. The substrate strip is guided between two rollers of the conveyor device 2 and conveyed by rotating the rollers. The forming tools, i.e. the anode tool 31a and the cathode tool 31b, have an integrated separating device 41. This means that anode plates 91 and cathode plates 92 are formed from the conveyed substrate strip in one work step by means of the anode tool 31a.Cathode plates 92 are formed by means of the cathode tool 31b and at the same time are separated from the substrate strip 97 except for residual webs. The anode plates 91 or the cathode plates 92 remain connected to the substrate strip 97 by these residual webs. This makes it possible to convey several of the connected anode plates 91 together or to convey several of the connected cathode plates 92 by advancing the substrate strip 97 via the conveyor device 2. In the joining device 4, the residual webs are severed, i.e. the anode plates 91 or cathode plates 92 are completely separated from the substrate strip 97 and subsequently joined together to form a bipolar plate 93. The bipolar plate 93 is then transported away from the joining device 4 and further processed into a bipolar plate stack 95 by means of the stacking device 6 in the same way as described above.

[0076] In the Fig. 6 shows an embodiment of a substrate magazine 96, which serves to deliver substrate strip 97. The substrate magazine comprises a holder for holding a reel 961 with substrate sheet. The substrate sheet 97 is unwound from the reel 961 and fed via a buffer 963 to a straightening device. The straightening device 962 comprises a transport device for transporting the substrate strip 97 and a pair of scissors. The transport device transports the conveyor belt to the conveyor device 2. In the illustration of Fig. 6, the conveyor device 2 is not shown; it is connected to the substrate magazine 96 on the left side. The shears are used to clean the edges of the substrate strip 97. The substrate strip 97, delivered as a coil or spool 961, often has transport damage in the edge area. These edges are cut or cleaned using the shears.

[0077] Buffer 963 serves as a material buffer to compensate for the irregular advance of the transport device. The substrate strip is continuously unwound from reel 961. However, the transport device does not transfer the substrate strip continuously, but cyclically to conveyor 2, according to its cycle rate. Buffer 963 is provided to enable continuous strip unwinding. The substrate strip 97 sags more or less in this area, forming a substrate strip reserve that compensates for the strip tension of the substrate strip 97.

[0078] A key feature of the illustrated embodiments is that pre-coated substrate strips are used as substrate material 97. This means that in all the illustrated embodiments, no subsequent coating of the formed substrate plates is necessary. This means that the complex coating processes known and necessary from the prior art can be dispensed with.

[0079] In order to remove any contaminants from the plates between the individual processing stations, it can be provided that the press device 5 has cleaning agents, for example in the form of compressed air nozzles or brushes, in order to clean the plates, i.e. the substrate plates 98 and / or the anode plates 91 and / or the cathode plates 92 and / or the bipolar plates 93. Cleaning can be carried out by blowing with compressed air or brushing. It can be provided that the compressed air nozzles or the brushes are stationary on the press device 5 and the cleaning takes place during the transport of the plates by means of the conveyor device, in that the conveyor device 2 conveys the plates 98, 91, 92, 93 past a compressed air nozzle or a brush.

[0080] The Fig. Figure 4 shows an enlarged view of the press device 5 with a conveyor device 2. The conveyor device 2 has two transport beams 21 and 22, respectively. Each transport beam 21 and 22 is mounted in the region of its end on a vertical press stand 52a, 52b, 52c, 52d by means of a rocker arm 28 and a lifting carriage 27. The lifting carriage 27 has a vertical drive to move the transport beam 21 and 22 in the lifting direction.

[0081] Several transport carriages 24 are arranged on each transport beam 21 or 22. The transport carriages 24 can be moved relative to the support beams 21 or 22. For this purpose, the transport carriages 24 each have a drive device with its own drive motor. The drive motor can be designed as an electric linear motor and move the transport carriage by means of magnetic interaction with a stator of the support beam 21 or 22. Alternatively, the drive motor can also be designed as a server motor that moves the transport carriage 24 by means of a gear and rack engagement. Each transport carriage can be controlled independently via a control device. A tool gripper 23 is removably mounted on each transport carriage 24. The control device is also connected to each tool gripper 23 in order to be able to control it individually with the aim of selectively picking up or placing down individual plates 98, 91, 92, 93.

[0082] A rocker arm 25 is rotatably mounted on each lifting carriage 27. The rocker arm has a rotary drive 28 at its end connected to the lifting carriage 27, by means of which the rocker arm 25 can be rotated. At its other end, the rocker arm 25 has a pivot bearing, which, for example, has a parallelogram linkage or another rotary drive, in order to maintain the vertical or horizontal alignment of the connected transport beam 21, 22 constant when the rocker arm 25 rotates ( Fig.5). A clamping movement, i.e. a movement transverse to the workpiece transport direction, can be achieved by a combined control of the rotary drive 28 and the lifting drive of the lifting carriage 27. The rocker arm 25 is rotated via the rotary drive 28. As a result of the rotary movement, the support beam 21 or 22 experiences a first movement component transverse to the transport direction, i.e. in or against the desired clamping direction, and a second movement component in the vertical direction. The movement component in the vertical direction is compensated for by counter-acting the lifting carriage 27, so that the height of the support beam 21 or 22 remains unchanged. In this way, it is possible to carry out a linear horizontal movement in or against the clamping direction with the support rails 21 or 22 rotatably mounted via the rocker arm 25, without any height deviation occurring. List of reference symbols 1 Device for the production of bipolar plates 2 Conveyor device 21 first transport beam 22 second transport beam 23 workpiece grippers 24 transport carriages 25 swingarm 26a first conveyor belt 26b second conveyor belt 27 lifting carriages 28 rotary drive 3 Forming device 31 Embossing tool 31a Anode tool 31b Cathode tool 4 Joining device 41 Separator 5 Press equipment 51 Press table 52a vertical press stand 52b vertical press stand 52c vertical press stand 52d vertical press stand 53 Lock box 6 Stacking device 61 Switch 62 Cross conveyor belt 91 Anode plate 92 Cathode plate 93 Bipolar plate 94 Membran 95 stack / bipolar plate stack 95d cover plate 95b base plate 96 substrate magazine 961 coil 962 straightening device 963 belt buffer 97 Substrate tape 98 substrate plate

Claims

[1] Device for producing bipolar plates for fuel cells, comprising a conveying device (2), a forming device (3) and a joining device (4), wherein the conveying device (2) transports substrate plates (98) in an automatically driven manner in a transport direction first to the forming device (3) and then to the joining device (4), wherein the forming device (3) embosses structures into the substrate plates by means of at least one embossing tool (31) or at least one forming tool and thereby forms a substrate plate (98) into an anode plate (91) or a cathode plate (92), and wherein the joining device (4) joins an anode plate (91) and a cathode plate (92) to form a bipolar plate (93), characterized by , in that the conveying device (2) has a transport beam (21, 22) with at least one workpiece gripper (23) for gripping substrate plates (98) and / or anode plates (91) and / or cathode plates (92), wherein the transport beam (21, 22) extends from the forming device (3) to the joining device (4) and a conveyor drive device is connected to the transport beam (21, 22) in order to move the workpiece gripper (23) and / or the transport beam (21, 22) in or against the transport direction in an automatically driven manner, and to move the workpiece gripper (23) and / or the transport beam (21, 22) in a lifting direction and / or in a clamping direction in an automatically driven manner. [2] Apparatus for producing bipolar plates according to claim 1, characterized bythat the forming device (3) is designed as part of a press device (5), wherein it is preferably provided that the press device (5) has vertical press stands (52a, 52b, 52c, 52d) and a press table (51) arranged between the press stands and the transport beam (21, 22) runs parallel to a longitudinal side of the press table (51). [3] Apparatus for producing bipolar plates according to claim 1 or 2, characterized by that the conveying device (2) has at least two transport beams (21, 22) running parallel to one another in the transport direction, wherein each transport beam has at least one workpiece gripper (23) for gripping substrate plates (98) and / or anode plates (91) and / or cathode plates (92). [4] Apparatus for producing bipolar plates according to one of claims 1 to 3, characterized byin that the transport beam (21, 22) is mounted on or on a locking box (53), wherein the locking box (53) has a lifting drive to drive the transport beam (21, 22) in a lifting direction and / or has a clamping drive to drive the transport beam (21, 22) in a clamping direction and / or has a longitudinal drive to drive the transport beam (21, 22) in the transport direction. [5] Apparatus for producing bipolar plates according to one of claims 1 to 3, characterized by that the transport beam (21, 22) is mounted in the region of its ends on a vertical press stand (52a, 52b, 52c, 52d) via a lifting carriage (27) driven by a lifting drive so as to be displaceable in the vertical direction, and the lifting carriage (27) rotatably supports one end of a rocker (25), the other end of which is connected to the transport beam. [6] Apparatus for producing bipolar plates according to one of the preceding claims, characterized bythat the workpiece grippers (23) are removably mounted on the transport beam (21, 22) or a transport carriage (24) of the transport beam (21, 22). [7] Apparatus for producing bipolar plates according to one of the preceding claims, characterized by in that at least two movable transport carriages (24) are mounted on a transport beam (21, 22), each of these two transport carriages (24) holding a workpiece gripper (23) and having its own drive device in order to move this transport carriage (24) independently of other transport carriages along the transport beam (21, 22). [8] Apparatus for producing bipolar plates according to one of the preceding claims, characterized by that a workpiece gripper (23) is mounted on a transport carriage (24) so ​​as to be movable in the lifting direction, in that the transport carriage (24) has a vertical drive for raising and / or lowering the workpiece gripper (23). [9] Apparatus for producing bipolar plates according to one of the preceding claims, characterized by that the conveying device (2) has a conveying control device or is connected to a conveying control device, wherein the conveying control device controls the transport beam (21, 22) and / or a workpiece gripper (23), in particular that the conveying control device determines a movement profile of the transport beam (21, 22) and / or a workpiece gripper (23). [10] Apparatus for producing bipolar plates according to one of claims 7 to 9, characterized bythat the drive device of the transport carriage (24) is connected to a carriage control device and the carriage control device is designed to control an individual transport carriage (24) and / or an individual workpiece gripper (23), preferably that the carriage control device is connected to the conveyor control device or is integrated therein. [11] Device for producing bipolar plates for fuel cells, comprising a conveying device (2), a forming device (3) and a joining device (4), wherein the conveying device (2) transports either individual substrate plates (98) or a plurality of interconnected substrate plates (98), automatically driven in a transport direction first to the forming device (3) and then to the joining device (4), wherein the forming device (3) embosses structures into the substrate plates by means of an embossing tool (31) or forming tool and thereby forms a substrate plate (98) into an anode plate (91) or a cathode plate (92), and wherein the joining device (4) joins an anode plate (91) and a cathode plate (92) to form a bipolar plate (93), characterized by , that the forming device (3) has at least one anode tool (31a) for forming anode plates (91) as a first embossing tool (31) or forming tool and, spaced apart in the transport direction, has at least one cathode tool (31b) for forming cathode plates (92) as a further embossing tool (31) or forming tool, and the joining device (4) is arranged between the anode tool (31a) and the cathode tool (31b), and that the conveying device (2) moves the anode plates (91) and cathode plates (92) in opposite directions to one another in the transport direction and transports one anode plate (91) and one cathode plate (92) each to the joining device (4). [12] Apparatus for producing bipolar plates according to claim 11, characterized bythat the conveying device (2) for transporting substrate material and / or substrate plates (98) and / or anode plates (91) and / or cathode plates (92) has a roller transport device or an eddy current transport device. [13] Apparatus for producing bipolar plates according to claim 11 or 12, characterized by that the conveying device (2) has two conveyor belts (26a, 26b), each guided over two deflection rollers and driven in opposite directions, one of the conveyor belts (26a, 26b) transporting the anode plates (91) and the other of the conveyor belts (26a, 26b) transporting the cathode plates (92). [14] Apparatus for producing bipolar plates according to claim 13, characterized byin that the conveying device (2) has a transport beam (21, 22) with at least one tool gripper (23) for gripping substrate plates (98) and / or anode plates (91) and / or cathode plates (92), wherein the transport beam (21, 22) extends from the anode tool (31a) to the cathode tool (31b) and has a conveyor drive in order to move the transport beam (12, 22) and / or the workpiece gripper (23) in or against the transport direction in an automatically driven manner, and to move the workpiece gripper (23) and / or the transport beam (21, 22) in a lifting direction and / or in a clamping direction in an automatically driven manner. [15] Apparatus for producing bipolar plates according to one of claims 11 to 14, characterized bythat the forming device (3) is designed as part of a press device (5), wherein it is preferably provided that the press device (5) has vertical press stands (52a, 52b, 52c, 52d) and a press table (51) and the transport beam (21, 22) runs parallel to a longitudinal side of the press table (51). [16] Apparatus for producing bipolar plates according to one of claims 11 to 15, characterized by that the press device (5) has a first press punch which cooperates with the anode tool (31a) and a second press punch which cooperates with the cathode tool (31b). [17] Apparatus for producing bipolar plates according to one of claims 14 to 16, characterized bythat the conveyor control device controls the conveyor device (2) with such a movement profile that the conveyor device (2) places a cathode plate (92) on an anode plate (91) in the area of ​​the joining device (4) or places an anode plate (91) on a cathode plate (92) by controlling the transport bar (21, 22) and / or a workpiece gripper (23) in such a way that it first places a cathode plate (92) or an anode plate (91) in a holder of the joining device (4) and then an anode plate (91) or a cathode plate (92) is lifted in the lifting direction by the transport bar (21, 22) and / or a further workpiece gripper (23), moved at least partially in overlap with the inserted cathode plate (92) or anode plate (91) and lowered by the transport bar (21, 22) and / or the further workpiece gripper (23) is positioned on the inserted cathode plate (92) or anode plate (91). [18] Apparatus for producing bipolar plates according to one of the preceding claims, characterized by that the joining device (4) is a welding device, in particular a laser welding device or an electrode welding device or a plasma welding device. [19] Apparatus for producing bipolar plate stacks, comprising an apparatus for producing bipolar plates according to one of the preceding claims, characterized by that the joining device (4) transfers a bipolar plate (93) to a further transport device, which conveys the bipolar plate (93) transversely to the transport direction and feeds it to a stacking device (6). [20] Apparatus for producing bipolar plate stacks according to claim 19, characterized by that the further transport device has a transverse conveyor belt (62) which is guided in a rotating manner over two deflection rollers. [21] Apparatus for producing bipolar plate stacks according to claim 19, characterized by that the further transport device has a driven conveyor arm with a workpiece gripper (23). [22] Apparatus for producing bipolar plate stacks according to one of claims 19 to 21, characterized by in that the stacking device (6) alternately stacks a bipolar plate (93) and a membrane (94) on a fuel cell stack and forms two fuel cell stacks, in that the stacking device (6) has a switch (61) to supply a bipolar plate (93) either to a first fuel cell stack or to a second fuel cell stack. [23] Apparatus for producing bipolar plate stacks according to claim 22, characterized by that the switch (61) is arranged laterally next to the conveying device (2) at the level of the joining device (4). [24] Apparatus for producing bipolar plate stacks according to claim 22 or 23, characterized bythat the first fuel cell stack is arranged laterally next to the conveying device (2) at the level of the anode tool (31a) and the second fuel cell stack is arranged laterally next to the conveying device (2) at the level of the cathode tool (31b). [25] Apparatus for producing bipolar plates or bipolar plate stacks according to one of the preceding claims, characterized by in that two roll magazines with substrate rolls are arranged in front of and behind the conveyor device (2) in the transport direction, wherein the first roll magazine supplies substrate strip (97) in the transport direction to the conveyor device (2) and the second roll magazine supplies substrate strip (97) against the transport direction to the conveyor device (2). [26] Apparatus for producing bipolar plates or bipolar plate stacks according to claim 25, characterized bythat the substrate strips (97) are designed as metal strips which have a reactive coating and / or a catalyst coating. [27] Apparatus for producing bipolar plates or bipolar plate stacks according to claim 25 or 26, characterized by that in a transfer area between the substrate belt (97) and the conveyor device (2) a separating device (41) is provided which separates individual substrate plates (98) from the substrate belt (97). [28] Process for the production of bipolar plates for fuel cells, wherein a bipolar plate (93) is formed by joining an anode plate (91) to a cathode plate (92) and, prior to joining, an anode plate (91) and a cathode plate (92) are formed from a substrate plate (98) by forming or embossing structures, characterized by , that a plate provided with a reactive coating and / or catalyst coating is used as the substrate plate (98) and that the method is carried out using a device according to one of claims 1 to 27. [29] A method for producing bipolar plates according to claim 28, characterized by that the forming and / or embossing of the substrate plates (98) is carried out in a press device (5) or a roller device. [30] A process for producing bipolar plates according to claim 28 or 29, characterized by that after forming or embossing, an anode plate (91) and a cathode plate (92) are automatically driven and transported to a joining device (4) and joined there to form a bipolar plate (93). [31] A process for producing bipolar plates according to any one of claims 28 to 30, characterized byin that, in order to join the bipolar plate (93), a cathode plate (92) is placed on an anode plate (91) by means of a conveyor device (2) in the region of the joining device (4), or an anode plate (91) is placed on a cathode plate (92) by the conveyor device (2) first placing a cathode plate (92) or an anode plate (91) into a holder of the joining device (4) and then the conveyor device (2) moves an anode plate (91) or a cathode plate (92) at least partially in overlap with the inserted cathode plate (92) or anode plate (91) and then places it on the inserted cathode plate (92) or anode plate (91). [32] A process for producing bipolar plates according to any one of claims 28 to 31, characterized by that after the forming or embossing step, the anode plate (91) and / or the cathode plate (92) are not coated with a reactive coating or a catalyst coating. [33] A process for producing bipolar plates according to any one of claims 28 to 32, characterized by that after the step of joining an anode plate (91) with a cathode plate (92) to form a bipolar plate (93), the bipolar plate is not coated with a reactive coating or a catalyst coating. [34] A method for producing bipolar plate stacks using a bipolar plate (93) produced by a method according to claims 28 to 33, characterized by that after joining, the bipolar plate (93) is automatically driven and transported to a stacking device (6) and there combined with a membrane (94) and stacked to form a fuel cell stack, and that the method is carried out using a device according to one of claims 1 to 27.

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