Method and production equipment for the manufacture and processing of structured sheets and stacking arrangement of structured sheets

Abstract

A method for producing and processing structured plates (1, 1'), in which a metal strip (3) is structured three-dimensionally to form connected structured plates (1, 1') and the structured plates (1, 1') are processed, a notch (2) is made continuously transversely to a longitudinal direction (C) of the metal strip (3) at intervals corresponding to a length or multiple of the length of the structured plates (1, 1'), and / or continuously in the longitudinal direction (C) of the metal strip (3) either in the center of the metal strip (3) or at intervals corresponding to a width of the structured plates (1, 1'), wherein the structured plates (1, 1') are connected to each other at a notch base (20) of the respective notch (2), and the metal strip (3) is folded along the respective notch(es) (2), characterized in thatthat the notch (2) separates the back sides (12, 12') of the structured plates (1, 1') from each other and the front sides (11, 11') of the structured plates (1, 1') form a closed surface with a back side of the notch base (20).

Description

[0001] The present invention relates to a method for producing and processing structured plates, preferably bipolar plates for fuel cells, in which a metal strip is structured three-dimensionally to form connected structured plates, preferably bipolar half-plates, wherein a notch is made continuously transversely to a longitudinal direction of the metal strip, at intervals corresponding to a length or multiple of the length of the structured plates, and / or continuously in the longitudinal direction of the strip, either in the center of the metal strip or at intervals corresponding to a width of the structured plates, the notch not penetrating the material of the metal strip, wherein the structured plates are connected to each other at the bottom of the notch(es), and the metal strip is folded along the respective notch(es).Furthermore, the invention relates to a stacking arrangement of structured plates, preferably bipolar half-plates, in which the structured plates are each arranged in a connected zigzag pattern or on top of or next to each other, so that alternately either two front sides or two back sides of the structured plates are arranged opposite each other, wherein a continuous notch is formed between the structured plates or between groups of structured plates in the width direction and / or length direction of the structured plates, and wherein the structured plates are connected to each other at the respective notch bottoms of the notches.

[0002] From publication DE 10 2021 122 402 A1, a method and a device of the aforementioned type are known, with which bipolar plates for fuel cells are manufactured by forming. In this process, a thin metal strip is structured three-dimensionally. Since the long metal strip is difficult to handle, after the forming process, it is cut into individual bipolar half-plates by separating the plates by making cuts perpendicular to the strip's longitudinal direction, and these are then placed in a stack.

[0003] While the stack allows for compact intermediate storage of the bipolar half-plates, cutting the metal strip is relatively complex and not easily reproducible. To subsequently join the bipolar half-plates into bipolar plates, they must be individually lifted from the stack. This process is time-consuming, can damage the bipolar half-plates, and leads to alignment problems during assembly. Furthermore, this state of the art has the disadvantage that, after the metal strip is cut into individual bipolar half-plates, continuous processing with a single, continuous metal strip is no longer possible.

[0004] Furthermore, methods for manufacturing bipolar plates for fuel cells are known from documents EP 1 517 388 A1 and DE 10 2005 037 345 A1, in which metal strips are punched from a metal strip, the metal strips being only partially cut and / or connecting webs being formed between the metal strips, so that the strip material and the metal strips form a continuous structure. The metal strips are then pushed out of a central layer in alternating directions and subsequently overmolded with plastic to form a stamped strip. In this stamped strip, channels for the passage of reactive agents are formed through the plastic between the stamped metal strips arranged on both sides of the strip.The metal strips, arranged alternately at the top and bottom of the die-cutting strip, are only overmolded on the inside of the die-cutting strip during the injection molding process, so that the outer surfaces of the metal strips lying on the surface of the die-cutting strip can be arranged in direct contact with a gas diffusion layer of a membrane.

[0005] The bipolar plates, thus formed and connected by the metal strip, are then stacked on top of each other in one variant of the process, each by means of 180° bends. The 180° bend of the metal strip protrudes outwards in a loop-like fashion. A membrane carrying at least one gas diffusion layer is placed between the bipolar plates. While these processes can, in principle, be carried out continuously, they are very cumbersome and costly due to the numerous process steps. Furthermore, the punching process used in the known methods generates a significant amount of material waste, making the processes inefficient and the resulting products expensive, and necessitating corresponding disposal costs.

[0006] Furthermore, it is known from other areas of technology to fold metal foils in a zigzag pattern, similar to the classic corrugated cardboard manufacturing process, then arrange them on top of each other and fix them with a top layer, in order to form, for example, honeycomb-shaped catalyst support bodies, as described in German patent application DE 199 22 358 C1. The honeycomb structure is created by folding a corrugated piece of material, perforated along the fold lines, in a zigzag pattern across its surface. The perforations are formed by die-cutting, leaving narrow connecting webs. These webs are intended to ensure a precise fit and provide just enough support and connection between the material pieces with minimal pressure loss. To prevent plastic overstretching of the connecting webs, they are selectively heated in the respective bending area.For this purpose, all connecting webs at the folding lines are simultaneously brought to a forming temperature by resistance heating.

[0007] German patent application DE 10 2013 204 915 A1 discloses a device and a method for manufacturing a fuel cell. In the method, the structure of a membrane support of a membrane electrode assembly of the fuel cell to be formed is weakened by a predetermined bending area in the form of a double-sided indentation, in order to later be able to fold the material at the predetermined bending point.

[0008] In the publication DE 10 2015 003 151 B4, planar elements are etched from a ribbon-shaped metallic foil. These elements consist of identical plates connected by connecting sections designed as tabs or bridges. Each connecting section has a bending point extending along a bending line, formed by a weakening of the material. Along this bending point, the connecting section and the plates to which it is attached can be folded 180°. A trench-like depression is etched into the surface of the connecting section on both sides along the bending points, extending across the entire width of the connecting section. The object of the present invention is to provide a method for the production and processing of structured plates, in which the structured plates can be stacked, at least temporarily, with minimal labor and space requirements, and the resulting stacked arrangement is easily processable in subsequent processes. Furthermore, a stacked arrangement of structured plates is proposed that can be produced with minimal labor and space requirements and is easily processable.

[0009] The problem is solved, firstly, by a method for producing and processing structured plates, in which a metal strip is structured three-dimensionally to form connected structured plates, preferably bipolar half-plates, wherein a notch is made continuously transversely to the longitudinal direction of the metal strip, at intervals corresponding to a length or multiple of the length of the structured plates, and / or continuously in the longitudinal direction of the strip, either in the middle of the metal strip or at intervals corresponding to a width of the structured plates, without cutting through the material of the metal strip, wherein the structured plates are connected to each other at a notch base of the respective notch, and the metal strip is folded along the respective notch(es).wherein the notch separates the back sides of the structured plates from each other and the front sides of the structured plates form a closed surface with the back side of the notch base.

[0010] In the present invention, the term "structured plates" refers to planar, plate-shaped components which have incorporated depressions that are or can be shaped differently. For example, such depressions can be channel structures.

[0011] Each notch forms a groove, channel, or other linear depression in the metal strip. By creating the notch(es), the material of the metal strip is weakened at the corresponding notch location(s). The notch(es) weaken the material of the metal strip along a notch line. This allows the material of the metal strip to be easily folded or creased along the notch(es) into at least two sections of the metal strip connected at the notch bases. Thus, a defined local folding or creasing is possible at the notch(es).

[0012] The base of each notch is preferably designed to be so thin that the material of the metal strip folds at the point(s) defined by the respective notch(es) without a tool acting directly on the base of the notch and without manual action on the base of the notch, i.e., for example, simply by compressing the metal strip.

[0013] The metal strip can be folded with alternating folding directions to form a zigzag pattern. However, it is also possible for the folding direction to remain constant. The latter is advantageous when two adjacent structured plates are repeatedly folded in the same direction around the notch between them to separate the two structured plates.

[0014] The notch(es) can be created in the metal strip using forming techniques, such as embossing. Alternatively, the notch(es) can also be created in the metal strip using laser ablation.

[0015] The creation of the respective notch(es) can also be carried out in combination with a conventional embossing process in a forming press. In a progressive die, a direct combination of notching with the creation of other structures in the metal strip is conceivable, either in one forming stage of the die to produce the respective structured plate(s) or in a separate stage of the die. This may require discontinuous feeding of the metal strip, which is then achieved by a feeding system.

[0016] The respective notch(es) can be introduced into the metal strip before, during or after the structuring of the metal strip to form the three-dimensional structured plates.

[0017] When the respective notch(es) are cut, the metal strip can be transported continuously in the longitudinal direction using rollers, i.e., in a roll-to-roll process. This method enables a continuous feed of the metal strip. The process therefore does not need to be interrupted, resulting in high process efficiency.

[0018] Folding allows the resulting structured plates, preferably the resulting bipolar half-plates, to be arranged in a zigzag pattern or in a horizontal or vertical stack without needing to be separated from each other. This enables a continuous or at least semi-continuous process for further processing the resulting structured plates.

[0019] With the help of the defined folding or kinking point(s) resulting from the notch(es), it is possible to deflect the metal strip without large roller radii.

[0020] Furthermore, the notch(es) in the metal strip can be used to create a zigzag stack, which can serve as a material buffer. This allows the resulting structured sheets to be stacked in a space-saving manner, offering significant advantages over existing solutions such as subsequently winding the structured sheets onto a coil in strip form or arranging them in a loop.

[0021] Furthermore, the inventive method makes it possible to lay down the rigid metal strip with pre-formed structures as a stacked arrangement and, after intermediate transport, to reintroduce it into a roll-to-roll production device. Such a stacked arrangement can, for example, be placed in a container and thus transported gently.

[0022] Furthermore, folding can be used to arrange the front faces of the structured plates, preferably the bipolar half-plates, opposite each other particularly quickly and accurately, as is necessary, for example, for the formation of various connected structured plates such as bipolar plates, without the need to separate the structured plates beforehand. According to one embodiment of the invention, it is provided that, for the formation of the respective connected structured plate, the corresponding structured plates intended for each connected structural plate are alternately formed in the metal strip, folded over each other at the notch, and joined together. Only in a later process step are they separated from the metal strip as a connected pair of structured plates, whereby the respective notch can also be used for the separation.

[0023] The respective notch(es) also ensure optimal alignment of the structured plates in the direction of the metal strip as well as at right angles to it. Furthermore, the respective notch(es) can be used to align joining partners in a joining process.

[0024] The inventive method can thus be implemented as a roll-to-roll process. In the roll-to-roll process, energy- and time-consuming acceleration and deceleration processes are eliminated. Furthermore, processing on the virtually endless metal belt offers better handling possibilities than processing discretely separated individual components, which always have to be gripped, aligned, and precisely placed. With the inventive method, it is possible to perform the singulation of the structured plates at the latest possible point in the process sequence, ideally in the last process step. As a result, the manufacturing process of interconnected structured plates, such as bipolar plates, can be significantly optimized using the inventive method.

[0025] If, according to one embodiment of the invention, the notches are made in the metal strip transversely to the longitudinal direction of the strip at intervals corresponding to a length or multiple of the length of the structured plates, each of the metal strip sections has a structured plate or a group of structured plates arranged side by side transversely to the longitudinal direction of the strip.

[0026] Another embodiment of the invention, in which a continuous notch is made in the center of the metal strip along its longitudinal direction, without penetrating the strip material, is advantageous when related structured plates are positioned opposite each other transversely to the longitudinal direction of the strip. These structured plates can then be advantageously folded together along the notch. Similarly, pairs or groups of pairs of structured plates can be produced if, according to another embodiment of the invention, several continuous notches are made in the metal strip along its longitudinal direction, either at intervals corresponding to the width of the structured plates or at intervals corresponding to the width of the structured plates.

[0027] Particularly material-efficient or even waste-free work can be achieved if, according to one embodiment of the inventive method, the respective notch(es) is / are embossed into the material of the metal strip. Embossing typically produces no material waste. Furthermore, embossing the respective notch(es) is advantageous if the structuring of the structured plates is also carried out by embossing, for example with embossing rollers.

[0028] When multiple notches are made into the metal strip, all notches can be made from the same side of the strip. Alternatively, some notches can be made from the front and others from the back. The latter can be done alternately, for example. Depending on their geometry, direction of entry, and the frequency of folding in the process, the notches can be used as either folding notches or break notches. Along the folding notches, the metal strip material remains intact at the base of the notch despite the folding. At the break notch, the metal strip material is overstretched and thus breaks.

[0029] Furthermore, in one embodiment of the method according to the invention, it is provided that when several notches are made in the material of the metal strip, at least some of the notches are made with a different notch depth than other notches in the metal strip.

[0030] Accordingly, in an embodiment of the inventive method that depends on the latter embodiments, it is provided that, in order to separate pairs of the structured plates, the base of each notch is overstretched at every second notch, so that the base of the notch tears when the metal strip folds as a result of the overstretching. From the produced pairs of structured plates, individual connected structured plates can then advantageously be formed.

[0031] The folding of the metal strip can, for example, be carried out at the end of a process step performed at a station of a production device, and the folded metal strip can then be unfolded again at the beginning of a subsequent process step at a station of the production device further down the strip's length. Folding allows the metal strip, which has the structured plates, to be temporarily stored in a space-saving manner at a suitable position within the production device and processed directly after unfolding. Thus, the method according to the invention can be used to compensate for different processing times at individual stations of a production device without having to remove the metal strip from the production device. This enables semi-continuous and therefore efficient process control.

[0032] Another way of implementing the method according to the invention is to stack the metal strip between two process steps and / or at the end of a production device into a stacking arrangement formed from connected metal strip sections. Such a stacking arrangement can comprise just two or more structured plates, which are arranged one above the other or next to each other in the stack to save space. The respective stacking arrangement can remain directly on a production device and subsequently serve there as a material storage area for further processing of the structured plates.However, it can also be taken from a first production device, where, for example, the embossing of the structured plates has taken place, and transported to another production device, where continuous further processing of the structured plates can then be carried out, since they are still connected.

[0033] In one embodiment of the method according to the invention, it may be advantageous to rotate or tilt the generated stacked arrangement by an angle, such as 90° or another suitable angle. For example, the stacked arrangement in the form of vertically adjacent, yet interconnected, structured plates can be continuously produced on the first production device and then tilted into a horizontal orientation of the structured plates, thus facilitating transport of the stacked arrangement with its overlapping and interconnected structured plates.

[0034] The metal strip material folds particularly well at a suitable angle if the notch(es) has a cross-section that tapers towards its base. This tapered cross-section can be trapezoidal, possibly with rounded corners, or semicircular. However, other cross-sections, such as triangular or stepwise tapered notch cross-sections, can also be advantageous. Furthermore, the notch(es) can have a rectangular cross-section.

[0035] In a further advantageous embodiment of the method according to the invention, during the folding of the metal strip, when the structured plates are aligned at an acute, right or obtuse angle to each other, at least one intermediate layer, such as a membrane and / or a seal, is inserted between the structured plates.

[0036] Several of the intermediate layers can be inserted horizontally between the structured plates, suspended at a distance from each other, perpendicular to the longitudinal direction of the metal strip, or placed vertically between the structured plates.

[0037] The structured plates can be produced and processed on a production device which has a structuring device designed to structure a metal strip three-dimensionally to form connected structured plates, wherein the production device has at least one notching device acting transversely to a longitudinal direction of the metal strip and / or continuously in the longitudinal direction of the metal strip and at least one metal strip folding area downstream of the notching device.

[0038] In the production device, the metal strip is structured by means of the structuring device, which can be, for example, an embossing device or another forming device, to form structured plates.

[0039] The at least one notching device creates at least one notch in the metal strip material, either transversely to or along the strip's longitudinal direction. The notch(es) form a weakening line in the metal strip material, along which the strip can be easily folded or creased mechanically. By folding or creasing, the structured plates formed in the metal strip can be arranged in a zigzag pattern relative to each other or in a horizontal or vertical stack, thus enabling the continuous or semi-continuous processing options described above, while simultaneously increasing efficiency and quality.

[0040] The notching device is preferably a notching embossing device, but can also be another forming device or, for example, a laser device.

[0041] If a notching device is used as the notching device in the production equipment, work can be carried out without material waste that would otherwise need to be removed. The notching device forms at least one notch into the metal strip, thereby locally reducing the thickness of the metal strip without cutting it. It is also possible to integrate the notching device into the embossing rollers used to form the structured plates, thus introducing at least one notch into the metal strip material during the embossing of the structured plates themselves.

[0042] The notching device defines the position of each notch and allows it to be precisely cut into the metal strip material. This results in lower precision requirements for subsequent processing tools in the production equipment, as, for example, no cutting gap needs to be maintained.

[0043] Furthermore, the mechanical behavior of the notch can be adjusted via the cross-sectional geometry of the indentation made in the metal strip by the notch-making device. This allows for both a comparatively stiff behavior along the notch line and self-separation of adjacent structured plates through slight overbending of the notch base.

[0044] The notching device can, for example, have a notching cross-section that tapers towards the base of the notch to be formed or remains constant.

[0045] Particularly advantageous geometries for folding or creasing the metal strip material can be created if the notching device has a notching cross-section that tapers towards the base of each notch. This tapered cross-section allows the material to be easily folded while still holding it securely together at the base. For example, trapezoidal or semicircular notches can be embossed, the bases of which effectively hold sections of the metal strip together, yet the material can still be easily pierced.

[0046] If the production device includes, for example, a structuring device with embossing rollers, such as hollow embossing rollers, the metal strip can be moved continuously or semi-continuously through the production device in the longitudinal direction by means of the embossing rollers and at least one pair of transport rollers. The at least one pair of transport rollers can be positioned upstream and / or downstream of the embossing rollers in a strip feed direction of the metal strip through the production device.

[0047] However, the production device can also generally include a different structuring device, such as a different forming device that does not have embossing rollers. Furthermore, the production device may not include transport rollers.

[0048] For example, it is possible that the production device first includes a notching device, in which, for example, at least one notch is made in the metal strip in a deep drawing step or an embossing step, followed by the metal strip folding area, in which the metal strip is folded in a zigzag pattern at the notches and folded in a stacking arrangement, after which the metal strip is structured three-dimensionally to form the structured plates.

[0049] In a preferred embodiment of the production device, the metal strip folding area has a stop for the metal strip oriented transversely to the strip's longitudinal direction. The metal strip material, moved by the rollers in the strip's longitudinal direction, can be accumulated at the stop, causing the metal strip to fold automatically along at least one notch formed transversely to the strip's longitudinal direction.

[0050] In a further advantageous embodiment of the production device, the metal strip folding area has a folding or folding device acting transversely to the longitudinal direction of the metal strip. This folding or folding device can be used to fold and / or overlap the metal strip around its center line. This embodiment can be used if at least one notch extending in the longitudinal direction of the strip has been created, along which the metal strip can be folded or folded over transversely to the longitudinal direction. The folding or folding device can, for example, have a ramp formed on one side under the metal strip. A first side of the metal strip can be lifted over the ramp, and this lifted side can then be folded over to the other side of the metal strip.

[0051] It is particularly advantageous if the production device has an insertion device at the at least one metal strip folding area for inserting at least one intermediate layer into the metal strip folds. In this way, the at least one intermediate layer can be inserted between the structured plates in the preferably zigzag-shaped folds of the metal strip, preferably while the structured plates are still connected and can thus be processed continuously, thereby forming connected, but subsequently easily separable, structured plates.

[0052] The problem is further solved by a stacking arrangement of structured plates, in which the structured plates are arranged in a continuous zigzag pattern, either on top of each other or next to each other, such that either two front sides or two back sides of the structured plates are alternately arranged opposite each other, wherein a continuous notch is formed between the structured plates or between groups of structured plates in the width and / or length direction of the structured plates, wherein the structured plates are connected to each other at the respective notch bottoms, wherein the notch separates back sides of the structured plates from each other and front sides of the structured plates form a closed surface with a back side of the notch bottom.

[0053] In this stacking arrangement, the structured plates lie directly on top of or next to each other and are connected to each other via the notched bottoms of the notches, without any connecting elements protruding laterally. This allows the structured plates to be stored compactly in the stacking arrangement.

[0054] Since the structured plates remain connected despite being stacked, the stacked arrangement can be used effectively for temporary storage of the structured plates during processing. The stacked arrangement can then be unfolded, allowing the structured plates to be processed together in a cohesive manner. Furthermore, the notched bases create a predetermined breaking point between the structured plates. This point can be easily cut with minimal force and bending against the fold, or with repeated folding at the respective notches, enabling the clear separation of related pairs of structured plates.

[0055] In a preferred embodiment of the stacking arrangement according to the invention, either all notches are made from the same side of the metal strip, or some notches are made from the front of the metal strip and others from the back. If, for example, the notches are made alternately from the front and back of the metal strip, the structured plates are connected to each other at the respective notch bases, which are located alternately on the front and back of the metal strip.

[0056] Regardless of which side the notches are made from in the metal strip, at least some of the notches may be designed in such a way that, when bent, the notch flanks of the respective notch support each other, thereby overstretching and tearing the notch base of the respective notch.

[0057] The likelihood of a notch tearing can also be determined by its depth. For example, if the notch base has a thickness of only 5 to 15%, or 10%, of the thickness of the unnotched metal strip, even a slight bend in this notch is sufficient to tear the base and separate the structured plates adjacent to this notch from each other or from the metal strip.

[0058] Accordingly, in a suitable embodiment of the stacking arrangement according to the invention, it is provided that some of the notches are made in the metal strip with a different notch depth than other notches.

[0059] To form connected structured plates, such as bipolar plates, from the stacking arrangement according to the invention, it is advantageous if at least one intermediate layer, such as a membrane electrode unit and / or a seal, is already located between the structured plates in the stacking arrangement.

[0060] It is also advantageous if the intermediate layers are formed from a zigzag-folded insert strip containing the intermediate layers.

[0061] Preferred embodiments of the present invention, their structure, function and advantages are explained in more detail below with reference to figures, wherein the Fig. Figures 1 to 3 schematically show a folding of two connected structured plates in a folding direction according to an embodiment of the method according to the invention, each in a side view; the Fig. Figures 4 to 6 schematically show a folding of two connected structured plates in a fracture direction and a breaking of the connection between the structured plates according to an embodiment of the method according to the invention, each in a side view; the Fig. 7 and Fig. 8 schematically show possible orientations of a stacking arrangement of structured plates according to the invention, each in a side view; Fig. Figure 9 schematically shows a possible process flow of the inventive method for producing connected structured plates on an embodiment of the inventive production device in a side view; Fig. Figure 10 schematically shows partial steps of an embodiment of the method according to the invention carried out on an embodiment of the production device according to the invention in a side view, in which folded, connected structured plates are stacked to form a stacking arrangement of structured plates according to the invention and subsequently the stacking arrangement of structured plates is unfolded; Fig. Figure 11 schematically shows a variant for inserting intermediate layers between relatively folded, interconnected structured plates according to a partial step of an embodiment of the inventive method on an embodiment of the inventive production device in a side view; Fig. 12 schematically one at the in Fig. 11 shows the suspended structural plate of the production device in a front view; Fig. 13 schematically shows a further variant for inserting intermediate layers between relatively folded structured plates according to a partial step of a further embodiment of the inventive method on a further embodiment of the inventive production device in a side view; Fig. Figure 14 schematically shows another variant for inserting intermediate layers between relatively folded, interconnected structured plates according to a partial step of another embodiment of the inventive method on another embodiment of the inventive production device in a side view; Fig. Figure 15 schematically shows a folding of a metal strip having structured plates along a longitudinal direction of the strip with the insertion of intermediate layers between the relative to each other folded, connected structured plates in a top view of the metal strip according to an embodiment of the inventive method; Fig. Figure 16 schematically shows another possible process flow of the inventive method for producing connected structured plates on an embodiment of the inventive production device in a side view; and the Fig. Figures 17 to 22 show schematically different geometries of a notch made in a metal strip in cut side views.

[0062] The Fig. Figures 1 to 3 schematically show a folding of two connected structured plates 1, 1' in a folding direction A according to an embodiment of the method according to the invention, each in a side view.

[0063] In the illustrated embodiment, the structural plate 1 is a bipolar half-plate configured to form an anode within a bipolar plate. In the illustrated embodiment, the structural plate 1' is a bipolar half-plate configured to form a cathode within the bipolar plate.

[0064] Although the present invention is described below with regard to the manufacture of bipolar plates, it can equally be used for the manufacture of other interconnected structured plates composed of thin structural or individual plates, such as electrolyzer plates or heat exchanger plates. When an intermediate layer is mentioned below, this refers to any intermediate layer, preferably planar, such as a membrane or a seal, or to a plurality of planar intermediate layers.

[0065] In Fig. 1. The two structured plates 1, 1' lie in one plane. The plane is defined by, for example, a Fig. Figure 15 shows a metal strip 3 in which the structured plates 1, 1' are formed. The metal strip 3 consists of metal sheet, for example, titanium sheet. The metal strip 3 has a thickness D in the range of 0.05 mm to 1.0 mm, for example, 0.5 mm.

[0066] The structured plates 1, 1' are connected by a connecting web, which is formed by a notched base 20 of a notch 2 formed in the metal band 3 between the structured plates 1, 1'. The notched base 20, and thus the connecting web, has a smaller thickness d than the structured plates 1, 1', which have a thickness D.

[0067] The thickness d of the notched base 20 is, for example, 1 / 10 to 1 / 5 of the thickness of the unnotched metal strip 3.

[0068] In the illustrated embodiment, the notch 2 is introduced into the material of the metal strip 3 by embossing, but it can also be introduced by another method.

[0069] The notch 2 separates the back sides 12, 12' of the structured plates 1, 1' from each other. The front sides 11, 11' of the structured plates 1, 1' form in the Fig. The straight alignment of the structured plates 1, 1' shown in Figure 1 with the back of the notched base 20 forms a closed surface.

[0070] In the illustrated embodiment, the notch 2 has a shape that tapers towards the notch base 20 when it is created. In the illustrated embodiment, the Fig. The notch 2 shown in Figure 1 has a trapezoidal cross-section, but in other embodiments of the present invention, not shown, it can also have a different cross-section, for example a semicircular one.

[0071] The Fig. Figures 17 to 22 schematically show various possible geometries of notches 2a, 2b, 2c, 2d, 2e, and 2f, each cut into a metal strip 3. Notch 2a has a triangular cross-section. Notch 2b has a trapezoidal cross-section. Notch 2c has a rectangular cross-section with rounded edges 210 at the base 20. Notch 2d has a rectangular cross-section. Notch 2e has a semicircular cross-section. Notch 2f has a trapezoidal cross-section with rounded edges 210 at the base 20.

[0072] In Fig. 2 becomes a first structured plate 1 of the two structured plates 1, 1' made of Fig. 1 is folded or folded in the folding direction A to a second structured plate 1' of the two structured plates 1, 1'. The folding direction A is oriented such that the inner side surfaces 21, 22 of the notch 2 are moved away from each other during the folding process.

[0073] During this folding process, the two structured plates 1, 1' remain connected to each other at the notched base 20.

[0074] Even when, as in Fig. As shown in Figure 3, the structured plates 1, 1' are moved further towards each other in the folding direction A, the two structured plates 1, 1' remain integrally connected to each other via the notched base 20. Fig. 3 The two structured plates 1, 1' are positioned on top of each other such that their front sides 11, 11' are opposite each other on the inside, while their back sides 12, 12' are arranged on the outside. The stacked structured plates 1, 1' form a simple embodiment of a stacking arrangement 10 according to the invention.

[0075] At the in Fig. 2 and Fig. During the folding or folding process shown in section 3, the shape of the notch 2 changes. In the illustrated embodiment, the notch base 20 initially forms, as shown in , a shape of . Fig. 2 shown, approximately a line with the inner surfaces 21, 22 of the notch 2, until the inner surfaces 21, 22 of the notch 2 form an obtuse angle with the base of the notch 20 and the base of the notch 20 forms an outer edge of the Fig. 3 shown stacking arrangement 10 of the structured plates 1, 1' forms.

[0076] Fig. Figure 4 shows a side view of two connected structured plates 1, 1', which are joined together by a notched base 20 of a notch 2 formed in a metal band (not shown here) in which the structured plates 1, 1' are formed. As in the Fig. 1 to 3 the notch 2 is preferably embossed and has in Fig. The linear alignment of the structured plates 1, 1' shown in 4 has a trapezoidal cross-section relative to each other, but it can also be shaped differently.

[0077] In the Fig. 5 and Fig. The two will be in 6 Fig. The 4 shown, interconnected structured plates 1, 1' are folded or folded towards each other in a fracture direction B. The fracture direction B is opposite to that shown in the Fig. 2 and Fig. 3. The folding direction A shown is aligned. The inner side surfaces 21, 22 of the notch 2 are moved towards each other until edges 201, 202 of the notch 2 are aligned, as shown in Figure 3. Fig. As can be seen, they are bumping into each other.

[0078] As it is in Fig. As can be seen in Figure 6, the structured plate 1 is then pressed further in the fracture direction B and / or the structured plate 1' is pressed in the opposite direction towards the structured plate 1. The converging movement of the structured plates 1, 1' in the fracture direction B creates a leverage effect that concentrates the load on the notch base 20, causing the notch base 20 to overstretch and ultimately fracture at a fracture point 23. Accordingly, the partial indentation formed by the notch 2 can enable the controlled separation of adjacent structured plates 1, 1' when the originally connected structured plates 1, 1' are folded together. This eliminates the need for an additional separation step.

[0079] In an embodiment of the present invention not shown, the separation process described above by overstretching the notch base 20 can be supported by at least one scoring notch formed on an outside side of the notch base 20.

[0080] The Fig. 7 and Fig. Figure 8 schematically shows possible orientations of the stacking arrangement 10 of structured plates 1, 1' according to the invention, each in a side view. In the Fig. In the stacking arrangement shown in 7, there is a plurality according to the one in the Fig. The folding principle shown in Figures 1 to 3 involves folded structured plates 1, 1' stacked on top of each other, with the structured plates 1, 1' being horizontally oriented. The structured plates 1, 1' of the stacking arrangement 10 are made of Fig. 8 are arranged side by side in a vertical orientation.

[0081] The inner structured plates 1, 1' of the respective stacking arrangement 10 are connected to each other in one piece via a notched base 20 with both adjacent structured plates 1, 1'.

[0082] Fig. Figure 9 schematically shows a possible process flow of the inventive method for the production of connected structured plates, such as bipolar plates, in a side view of an embodiment of a production device 100 according to the invention.

[0083] The production device 100 has the following stations arranged one after the other in a belt longitudinal direction C, whereby the production device 100 may also have further stations or individual stations of the exemplary shown may be omitted or arranged in a different order: At a strip feed station, a metal strip 3 is unwound from a feeder roll 101 with the aid of a pair of transport rollers 4. The metal strip 3 then passes through a pair of embossing rollers 5. In the exemplary embodiment shown, the structured plates 1, 1' are produced using hollow embossing rollers 5. However, the technology shown is not limited to the use of hollow embossing rollers.

[0084] The embossing rollers 5 have embossing structures on their surfaces that serve to form embossed structured plates 1, 1', such as bipolar half-plates, in the metal strip 3. In addition, in the illustrated embodiment, the embossing rollers 5 have embossing structures that serve as a notching device for forming notches 2 in the metal strip 3.

[0085] In other embodiments of the present invention not shown, the pair of embossing rollers 5 can serve only for embossing the structured plates 1, 1', wherein at least one notching device is positioned upstream or downstream of the pair of embossing rollers 5 in the longitudinal direction C of the strip.

[0086] The respective notching device is preferably an embossing device, but can also be another device, preferably another forming device, with which at least one notch 2 can be made into the metal strip 3, such as a punching device, a turning device, a milling device, a laser ablation device or the like. For example, at least two pairs of embossing rollers 5 can be provided, wherein the structured plates 1, 1' are formed in the metal strip 3 by one of these pairs of embossing rollers 5 and the notches 2 are formed by at least another pair of embossing rollers 5.

[0087] In the illustrated embodiment, the notching device creates continuous notches in the metal strip 3 transversely to the longitudinal direction C of the strip at intervals that correspond, for example, to a Fig. The length l of the structured plates shown in 16 corresponds to 1, 1', with notches 2 being made.

[0088] In the illustrated embodiment, the notches 2 are alternately introduced into the metal strip 3 from a front side 31 and from a back side 32, but in another embodiment of the invention they can also be introduced into the metal strip 3 from only one side.

[0089] In another embodiment of the invention, instead of or in addition to the notches 2 described above, which are made transversely to the longitudinal direction C of the metal strip 3, a corresponding notching device can be used to create notches continuously in the longitudinal direction C of the metal strip 3, either in the center of the metal strip 3 or at intervals that correspond, for example, to a specific notch pattern. Fig. A continuous notch 2, which does not pierce the material of the metal strip 3, is made in each of the structured plates 1, 1' shown in Figure 16. This notch 2 can be made from the front 31 or the back 32 of the metal strip 3. The respective notch 2 is preferably designed such that its cross-section tapers towards the notch base 20. For example, the cross-section of the notch 2 is trapezoidal, but can also be semicircular or otherwise shaped. The notch 2 is preferably stamped, but can also be produced by another method, as explained above.

[0090] In the illustrated embodiment, a further pair of transport rollers 4 is arranged downstream of the pair of embossing rollers 5 in the longitudinal direction C of the strip. A metal strip folding section 6 is formed downstream of this pair of transport rollers 4. In the metal strip folding section 6, the metal strip 3 is folded at the notches 2 in a similar manner to the above with regard to the Fig. The described elements 1 to 3 are folded in a zigzag pattern to form a stacking arrangement 10. Due to the folding, the structured plates 1, 1' are oriented upwards at an angle relative to the longitudinal direction C of the strip.

[0091] The zigzag stacking arrangement 10 offers significant advantages over a belt loop in terms of space requirements. By folding the metal belt in the folding area 6, a large number of structured plates 1, 1' can be temporarily stored or buffered until they can be further processed in a subsequent step on the same production device 100. This allows the metal belt folding area 6 to be advantageously used as a buffer in linked production processes.

[0092] A further pair of transport rollers 4 is arranged downstream of the metal strip folding section 6. This is followed by at least one processing station 7 for further processing of the structured plates 1, 1', of which only one is shown here as an example; this station is again followed by a pair of transport rollers 4. Downstream of this pair of transport rollers 4 in the longitudinal direction C of the strip is another processing station, which may, for example, include a spraying device 8.

[0093] At one end of the production device 100, a metal strip folding section 6 is provided in which the structured plates 1, 1' are folded and stacked to form a stacking arrangement 10 with vertically adjacent structured plates 1, 1'. In a subsequent step, the stacking arrangement 10 is rotated 90° according to arrow E, so that the structured plates 1, 1' then lie horizontally on top of each other. In the illustrated embodiment, this stacking arrangement 10 is placed in a container 9, which allows the stacking arrangement 10 to be transported, for example, to a further processing station for the structured plates 1, 1'.

[0094] At a metal strip folding area 6 or at an end area of ​​a production device 100, the following can also be used: Fig. The arrangement shown schematically is provided as shown in Figure 10. The arrangement shown comprises a container 9 in which a stacking arrangement 10 of structured plates 1, 1' according to the invention is formed in a metal band folding area 6 by folding a metal band 3 having notches 2 and arranging structured plates 1, 1' one above the other. The structured plates 1, 1' have, for example, pre-molded channel structures.

[0095] In a subsequent process step, the stacking arrangement 10 is unfolded, forming a metal band unfolding area 60, in order to enable further processing of the structured plates 1, 1' at a further processing station. A transport step for moving the container 9 filled with the stacking arrangement 10 can be provided between the two process steps shown, whereby the transport of the stacking arrangement 10 in the container 9 can be carried out in a manner that protects the components.

[0096] In the arrangement of Fig. The structured plates 1, 1' can be stacked at high speed to the stacking arrangement 10 and subsequently removed from the stacking arrangement 10 at high speed as well, since no individual parts need to be transported.

[0097] Fig. Figure 11 schematically shows a variant for inserting intermediate layers 13, such as membrane electrode units, between relatively folded, interconnected structured plates 1, 1' according to a partial step of an embodiment of the inventive method on an embodiment of the inventive production device 100 in a side view.

[0098] With the help of the in Fig. In the embodiment shown in Figure 11, the structured plates 1, 1' can be fitted with several intermediate layers 13 in parallel, which can accelerate the overall process.

[0099] The in the Fig. 11, Fig. 12 and Fig. The 13 process steps shown are carried out on a metal strip 3, which, as described in relation to Fig. As described above, the structure already consists of structured plates 1, 1' and notches 2 inserted transversely to the longitudinal direction of the band C.

[0100] In Fig. 11 one end of the metal band 3 meets a stop 14 oriented transversely to the band's longitudinal direction C. This causes the metal band 3 to be compressed and fold in a zigzag pattern at the notches 2 in the metal band folding area 6.

[0101] Above the metal strip folding area 6, in the embodiment of Fig. 11 An insertion device 15 is arranged. Intermediate layers 13 hang from the insertion device 15 at intervals corresponding to the intervals of the metal strip folds 16 formed in the metal strip 3. These intermediate layers are hooked into the metal strip folds 16 and placed therein. Thus, an intermediate layer 13 can be inserted between each associated structured plate 1, 1' in a continuous process without having to cut the metal strip 3.

[0102] The metal band folds 16 are guided here by guides 17. The guides 17 are in Fig. 12 can be seen, which schematically represent one at the in Fig. Figure 12 shows a front view of the bipolar half-plate 1 suspended in the production device. In order to hold the respective structured plates 1, 1' on the guides 17, they have corresponding lateral projections 18, which are suspended in the guides 17 similarly to a hanging file system.

[0103] Fig. Figure 13 schematically shows another variant of folding a metal band 3 and of inserting intermediate layers 13 between structured plates 1, 1' folded relative to each other in a side view according to a partial step of a further embodiment of the inventive method on a further embodiment of the inventive production device 100.

[0104] This embodiment of the production device 100 has a shaft 17 that is wide at the top and tapers downwards. The shaft 7 has shaft walls 171, 172, along which, on the one hand, the structured metal strip 3 and, on the other hand, an insert strip 130 having intermediate layers 13 and spaced-apart creases 131 are guided, as shown schematically by arrows F, F'. The distances between the creases 131 of the insert strip 130 are adapted to the distances between the notches 2 of the metal strip 3.

[0105] When the metal strip 3 and the insert strip 130 are inserted into the shaft 17, their ends each abut a stop 14, causing both strips 3 and 130 to be compressed. In the illustrated embodiment, the stop 14 is formed by a surface of a table 24 that can be moved away as indicated by arrow H. Due to the compression, the metal strip 3 folds at the notches 2 and the insert strip 130 folds at the creases 131. The insert strip folds 132 formed in the insert strip 130 then lie between the metal strip folds 16 of the metal strip 3, so that, in the illustrated embodiment, an intermediate layer 13 is located between the front faces 11 and 11' of the structured plates 1 and 1'. Thus, an intermediate layer 13 can be inserted between the associated structured plates 1, 1' in a continuous process without having to cut through the metal strip 3.

[0106] Fig. Figure 14 schematically shows another variant for inserting intermediate layers 13, such as membrane electrode units, between relatively folded, interconnected structured plates 1, 1', such as bipolar half-plates, according to a partial step of another embodiment of the inventive method on another embodiment of the inventive production device 100 in a side view.

[0107] In this embodiment, a stacked arrangement 10 of relative, interconnected, structured plates 1, 1' rests on a table 18, which can be moved upwards in a lifting direction G by a lifting device 19. In the illustrated method, the stacked arrangement 10 is unfolded, with each structured plate 1 or 1' being placed on a further table 24, this structured plate 1 or 1' still connected to the rest of the stacked arrangement 10. The further table 24 can be moved downwards in the direction indicated by arrow H. Thus, in this embodiment of the invention, the structured plates 1, 1' contained in the zigzag-shaped stacked arrangement 10 are transferred from the first table 18 to the second table 24 by a relative movement.

[0108] If, as in the example shown, the structure plate 1 is placed on the table 24, an intermediate layer 13 is placed on the structure plate 1 using a movable handling robot 25. Then the table 24 is moved downwards and the table 18 upwards, and afterwards the next structure plate 1' is folded over the intermediate layer 13.

[0109] During the folding over of the structured plates 1, 1', at least one further work step, such as cleaning, can be carried out, for example in Fig. 14 is represented by a spray device 31, an insertion of a seal or similar, is carried out on the structured plates 1, 1'.

[0110] Meanwhile, the handling robot 25 retrieves a next intermediate layer 13 from a stack 26 of individual intermediate layers 13, which in the exemplary embodiment is located in an adjacent container 9.

[0111] Fig. Figure 15 schematically shows a folding of a structured metal strip 3 comprising plates 1, 1', such as bipolar half-plates, along a strip longitudinal direction C with the insertion of intermediate layers 13, such as membrane electrode units, between the relative to each other folded, connected structured plates 1, 1' according to a further embodiment of the method according to the invention in a top view of the metal strip 3.

[0112] In the embodiment of Fig. 15 a notch 2 running in the longitudinal direction C of the band is made in the middle of the metal band 3 and notches 2 running transversely to the longitudinal direction C of the band are formed as described above.

[0113] In the representation of Fig. Figure 15 shows a metal strip folding area 6 of a production device 100, which simultaneously serves as an insertion area for the intermediate layers 13. The metal strip folding area 6 has a folding device (not shown) on a first side 27 of the metal strip 3, acting transversely to the strip's longitudinal direction, by which the metal strip 3 is folded from this side 27 to a second side 28 of the metal strip 3 in the direction of arrow I. In doing so, the metal strip 3 is folded along the central notch 2 running in the strip's longitudinal direction C. As a result of the folding, corresponding structured plates 1, 1' lie on top of each other with their front faces 11, 11'.

[0114] Before the first page 27 is completely folded over, an intermediate layer 13 is inserted laterally between the structured plates 1, 1' according to the arrow J.

[0115] The partial strips of the metal strip 3, laid transversely to the longitudinal direction C, are then connected on both sides at connection points 30 to form interconnected, linked structured plates, such as bipolar plates.

[0116] In a subsequent, in Fig. In the 15th process step not shown, the interconnected, linked structured plates 1, 1' are separated from each other at the notches 2 formed transversely to the longitudinal direction C of the strip.

[0117] Fig. Figure 16 schematically shows another possible process flow of the inventive method for the production of connected structured plates, such as bipolar plates, in a side view of a further embodiment of the inventive production device 100.

[0118] In this embodiment, a stacking arrangement 10 of structured plates 1, 1', such as bipolar half-plates, is used on the production device 100 to supply parallel process strands 71, 72; 71', 72' with material.

Claims

[1] A method for producing and processing structured plates (1, 1') in which a metal strip (3) is structured three-dimensionally to form connected structured plates (1, 1') and the structured plates (1, 1') are processed, a notch (2) is made continuously in the metal strip (3) transversely to a longitudinal direction (C) of the metal strip (3), at intervals corresponding to a length or multiple of the length of the structured plates (1, 1'), and / or continuously in the longitudinal direction (C) of the metal strip (3) either in the center of the metal strip (3) or at intervals corresponding to a width of the structured plates (1, 1'), the notch (2) not cutting through the material of the metal strip (3), wherein the structured plates (1, 1') are connected to each other at a notch base (20) of the respective notch (2), and the metal strip (3) is folded along the respective notch(s) (2), characterized by, that the notch (2) separates the back sides (12, 12') of the structured plates (1, 1') from each other and the front sides (11, 11') of the structured plates (1, 1') form a closed surface with a back side of the notch bottom (20). [2] Method according to claim 1, characterized by , that the respective notch(s) (2) is / are embossed into the material of the metal band (3). [3] Method according to claim 1 or 2, characterized by , that when several notches (2) are made into the material of the metal strip (3), either all the notches are made into the metal strip (3) from the same side, or some of the notches (2) are made into the metal strip (3) from a front (31) and some of the notches (2) are made into the metal strip (3) from a back (32). [4] Method according to any one of claims 1 to 3, characterized by, that if several notches (2) are made into the material of the metal strip (3), at least some of the notches (2) are made with a different notch depth than other notches (2) in the metal strip (3). [5] Method according to claim 3 or 4, characterized by , that to isolate groups of the structured plates (1, 1') at individual notches (2) the notch bottom (20) is overstretched. [6] Method according to any one of claims 1 to 5, characterized by , that the metal strip (3) is folded between two process steps and / or at one end of a production device (100) and the resulting connected metal strip sections are stacked to form a stacking arrangement (10) of structured plates (1, 1'). [7] Method according to claim 6, characterized by , that the stacking arrangement (10) of structured plates (1, 1') is rotated or tilted by an angle. [8] Method according to claim 6 or 7, characterized by , that the metal strip (3) is folded, cut along at least one of the notches (2) and then stacked into at least two stack arrangements (10) of structured plates (1, 1') which are processed separately but in parallel on the production device (100). [9] Method according to any one of the preceding claims, characterized by that the notch(s) (2) has / have a cross-section that tapers towards its notch base (20) or has a rectangular cross-section. [10] Method according to any one of the preceding claims, characterized by , that during the folding of the metal strip (3), when the structured plates (1, 1') are aligned at an acute, right or obtuse angle to each other, at least one intermediate layer (13) is inserted between the structured plates (1, 1'). [11] Method according to claim 10, characterized by, that several of the intermediate layers (13) are inserted horizontally between the structured plates (1, 1') or placed vertically between the structured plates (1, 1') at intervals from each other, perpendicular to the longitudinal direction of the strip (C). [12] Stacking arrangement (10) of structured plates (1, 1') in which the structured plates (1, 1') are arranged in a continuous zigzag pattern or on top of or next to each other, such that either two front sides (11, 11') or two back sides (12, 12') of the structured plates (1, 1') are alternately arranged opposite each other, wherein a continuous notch (2) is formed between the structured plates (1, 1') or between groups of the structured plates (1, 1') in the width direction (b) and / or length direction (I) of the structured plates (1, 1'), wherein the structured plates (1, 1') are connected to each other at the respective notch bottoms (20) of the notches (2), characterized by , that the notch (2) separates the back sides (12, 12') of the structured plates (1, 1') from each other and the front sides (11, 11') of the structured plates (1, 1') form a closed surface with a back side of the notch bottom (20). [13] Stacking arrangement according to claim 12, characterized by , that either all of the notches are made from the same side of the metal band (3) or some of the notches (2) are made into the metal band (3) from its front (31) and others of the notches are made into the metal band (3) from its back (32). [14] Stacking arrangement according to claim 12 or 13, characterized by , that some of the notches (2) are made with a different notch depth than other notches (2) in the metal strip (3). [15] Stacking arrangement according to one of claims 12 to 13, characterized by , that at least one intermediate layer (13) lies between each of the structured plates (1, 1'). [16] Stacking arrangement according to any one of claims 12 to 15, characterized by that several of the intermediate layers (13) are formed from a zigzag-folded insert strip (130) having the intermediate layers (13).

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