Fuel cell

Abstract

The invention relates to a fuel cell (1), comprising a bipolar plate (210), in particular a plurality of bipolar plates (210), and / or comprising a connecting means (9), in particular a plurality of connecting means (9), the bipolar plate (210) extending in a longitudinal direction (L) and in a width direction (B), the longitudinal direction (L) and the width direction (B) being in particular perpendicular to one another, the bipolar plate (210) having a plurality of perforations (240), the perforations (240) being arranged in the longitudinal direction (L) and the width direction (B). Wherein the feedthrough (240) has an outer contour, the outer contour of the feedthrough (240) being formed in particular by a mounting feedthrough (242) and at least one flow feedthrough (244), the mounting feedthrough (242) advantageously forming a circular arc-shaped part of the outer contour of the feedthrough (240), and wherein the mounting passage (242) or the passage (240) is designed to receive the connecting means or a connecting means (9).

Description

Technical Field

[0001] The present invention relates to a fuel cell. Background Art

[0002] Fuel cells are already known from the prior art. Fuel cells are used, in particular, to release electrons by using reactions in order to thereby generate electric current or to be able to provide energy. As fuel, different fluids, such as hydrogen, can be used. However, a problem with known systems is that the fuel cell consists of a plurality of cells, which are each separated from one another by bipolar plates. The cells are mostly arranged in a stacked manner and covered on the end sides by end plates in order to thereby achieve a compact design. The cells are fixed to one another and to the end plates mostly by external connecting means. However, the bipolar plates and the end plates are thus subjected to large bending stresses and / or this results in a high structural space requirement. Summary of the invention

[0003] It is therefore an object of the present invention to provide an arrangement which saves construction space and nevertheless enables secure fastening of the components of a fuel cell.

[0004] This object is achieved by a fuel cell according to claim 1 and by the use according to claim 15. Further advantages, features and embodiments emerge from the dependent claims, the description and from the drawings.

[0005] According to the present invention, a fuel cell is provided. The fuel cell comprises in particular a bipolar plate, in particular a plurality of bipolar plates, and / or in particular a connecting mechanism, in particular a plurality of connecting mechanisms, wherein the bipolar plate extends in a longitudinal direction and in a width direction, wherein the longitudinal direction and the width direction are in particular perpendicular to each other, wherein the bipolar plate has a plurality of perforations, wherein the perforations have an outer contour, wherein the outer contour of the perforations is in particular constituted by a mounting perforation and at least one flow perforation, respectively, wherein the mounting perforation advantageously constitutes an arc-shaped portion of the outer contour of the perforation, and wherein the mounting perforation or one of the perforations or one of the plurality of perforations is constituted to accommodate the or one connecting mechanism. The fuel cell is used to convert energy from a mostly chemically bonded form into another form, in particular electrical energy. The fuel cell comprises a bipolar plate and / or a connecting mechanism. The connecting mechanism will be further described below. However, it is important that at least one connecting mechanism, preferably a plurality of connecting mechanisms, and more particularly preferably all connecting mechanisms advantageously extend through the bipolar plate or through the perforations of some or all bipolar plates. In other words, some bipolar plates in the bipolar plate or a plurality of bipolar plates surround the connecting mechanism or surround the connecting mechanism. Thus, a particularly compact arrangement can be achieved. The bipolar plate is used to constitute or can constitute a part of a fuel cell. The bipolar plate extends in the longitudinal direction and in the width direction, wherein the longitudinal direction and the width direction are particularly perpendicular to each other, wherein the bipolar plate has a plurality of perforations, wherein the perforations have an outer contour, wherein the outer contour of the perforations is respectively constituted by a mounting perforation and at least one flow perforation, wherein the mounting perforation constitutes an arc-shaped part of the outer contour of the perforation, and wherein the mounting perforation is designed to accommodate a connecting mechanism. The bipolar plate is a component and / or can be arranged in a fuel cell or used therein. In particular, an MEA is respectively arranged between two bipolar plates. For the purposes of the present invention, "MEA" should be understood as a membrane-electrode unit. Therefore, the bipolar plate is used to be able to guide and / or guide fuel, especially hydrogen, and / or oxygen and / or combustion products, especially fluids, such as water or water vapor, from the MEA and / or to the MEA, and at the same time at least partially limit the accommodation volume for the MEA. In addition, the bipolar plate can be used in particular for conducting electrons. The bipolar plate is especially at least partially made of an electrically conductive material, and / or made of plastic and / or at least partially made of an insulating material. Therefore, the bipolar plate can especially form part of a stack or "stack" of a fuel cell. The bipolar plate extends especially in the longitudinal direction and in the width direction. The longitudinal direction is especially the direction in which the bipolar plate has its largest main dimension. On the contrary, the width direction can especially be the direction in which the width of the bipolar plate is measured. Perpendicular to the longitudinal direction and / or the width direction can be the height direction. The height direction can especially be the direction in which the material strength of the bipolar plate is measured. It is particularly suitable that the longitudinal direction and the width direction are perpendicular to each other. In addition, preferably, the longitudinal direction, the width direction and the height direction can especially be perpendicular to each other.In other words, the longitudinal direction, the width direction and the height direction can form a rectangular coordinate system with each other. The bipolar plate includes a plurality of penetrations. The penetration here especially completely penetrates the bipolar plate, wherein the main extension direction of the penetration is especially the height direction. In other words, the penetration can penetrate the bipolar plate in the height direction. It is thus feasible to guide the mechanism, especially the connecting mechanism, and / or the fluid through the bipolar plate. In other words, the penetration can therefore be used to: enable the fluid to flow from one side of the bipolar plate to the other side of the bipolar plate and also simultaneously provide a receiving space for a fastening mechanism, a connecting mechanism or a tensioning mechanism. Advantageously, the connecting mechanism is therefore a tensioning mechanism, i.e., a mechanism that provides or can provide a tensioning mechanism of the bipolar plate to each other. The connecting mechanism can also be a fastening mechanism or a fastening mechanism within the scope of the present invention. In particular, the flow penetration of the penetration is considered to be used for a fluid pipeline. The penetration itself is constituted here by being a component of the flow penetration and at least also by another component called the installation penetration. The mounting perforation is used here to accommodate one or the connecting mechanism, which may also be a tensioning mechanism, so as to achieve the "stacking" or tensioning of the bipolar plates and / or fuel cells. In other words, the perforation can therefore be formed by the combination of the mounting perforation and at least one flow perforation. Suitably, the bipolar plate basically has a plurality of perforations, each of which has at least one flow perforation and a mounting perforation. The perforation is arranged or configured so that it forms an outer contour on the bipolar plate. The outer contour is especially the outer edge of the perforation on the surface of the edge of the bipolar plate (especially in the height direction). The outer contour of a perforation or a plurality of perforations is at least partially formed by the flow perforation and at least partially by the mounting perforation. In other words, the edge of the perforation is at least partially formed by the mounting perforation and at least partially also by the flow perforation. The mounting perforation especially forms the arc-shaped part of the outer contour of the perforation. In other words, at least a portion of the external lead-through is thus formed by a circular segment, which also delimits the mounting lead-through. Alternatively, the lead-through can therefore have a segment in the form of a partial arc of a circle, which is formed exactly by the mounting lead-through. This makes it possible to achieve a particularly low-cut effect factor and production-friendly and compact design of the mounting lead-through, in particular adapted to a connecting means, in particular a connecting means in the form of a screw. A screw in the context of the invention can in particular be a connecting means having an actuating head and / or an actuating section and further having an external thread and / or an internal thread, which is in particular introduced into the shank section.

[0006] In a preferred embodiment, the bipolar plate has a flow area, wherein the flow area is used in particular to delimit a fluid volume, wherein the fluid volume is in particular connected to or can be connected to the fluid of at least two through-holes. The flow area is in particular an area of ​​the bipolar plate or one or more surfaces of the bipolar plate that are located outside and are surrounded in the height direction, and the area or the surface is in contact with or can be in contact with the MEA fluid. Therefore, the flow area can constitute or include a surface on the bipolar plate. Suitably, the bipolar plate has not only a flow area formed by a surface surrounded in the positive height direction, but also a flow area formed by a surface surrounded in the negative height direction. The flow area is used in particular to delimit a fluid volume that is connected to the MEA and / or to at least partially provide a volume in which the MEA is arranged. Therefore, the flow area in particular encloses a fluid volume that is connected to or can be connected to the fluid of at least two through-holes of the bipolar plate. This is particularly important when sealing elements are subsequently provided and / or are arranged on the bipolar plate, which sealing elements allow a fluid flow from one aperture to the flow region and from the flow region to another aperture. As a result, apertures, in particular flow penetrations of apertures, which are fluidically connected to the flow region or the fluid volume, can be used to enable a fluid inflow and outflow into the fluid volume.

[0007] Expediently, the installation passage and the flow passage of one or more passages penetrate the bipolar plate, thereby making it possible to achieve a particularly simple passage of the connection means and the flow fluid through the bipolar plate.

[0008] Advantageously, the flow passage is designed such that it extends in a plane spanned by the longitudinal direction and the width direction from the installation passage to the flow region. This allows a particularly flow-technically advantageous design of the flow passage to be achieved.

[0009] Suitably, the arc-shaped portion of the installation penetration constitutes at least 51%, preferably at least 65%, and particularly preferably at least 75% of the circle. In other words, the arc-shaped portion can constitute at least 51%, preferably at least 65%, and particularly preferably at least 75% of the complete circle. By the design scheme that at least 51% is constituted by the arc-shaped portion of the installation penetration, the position fixation of the connecting mechanism accommodated in the arc-shaped portion or the installation penetration can be achieved. In other words, by this design scheme, the shape-fitting position fixation of the connecting mechanism in the installation penetration is particularly guaranteed or at least provided in an emergency, so that in particular, the bipolar plate is prevented or can be prevented from sliding relative to the connecting mechanism in the longitudinal direction and the width direction plane. In order to further improve the shape-fitting fixation, the arc-shaped portion should constitute at least 65%, preferably at least 75% of the complete circle. It is thus possible to further improve the shape-fitting fixation between the bipolar plate and the connecting mechanism so as to achieve better accuracy of the position fixation. By this type of shape-fitting fixation of the bipolar plate relative to the connecting mechanism, a particularly simple installation can be achieved here. As a result, it is in particular possible to subsequently thread the individual bipolar plates onto the connecting means, so that assembly can be simplified.

[0010] However, preferably, the arc-shaped part of the mounting aperture forms a maximum of 98%, preferably a maximum of 90%, and particularly preferably a maximum of 80% of the circle. The missing part that forms a complete circle here particularly belongs to the flow aperture. In other words, this design can therefore ensure that there is enough space for the flow aperture in the aperture so that a sufficient flow surface or flow capability is provided.

[0011] Preferably, the bipolar plate has a flow groove, in particular in a flow region of the bipolar plate or in the flow region, wherein the flow groove ends and / or starts in particular in the through-hole. In other words, the bipolar plate can have a groove in a surface that delimits the bipolar plate in the height direction, which can promote and / or realize the fluid flow. The groove is particularly referred to as a flow groove here. Suitably, the flow groove extends on the bipolar plate or is arranged on the bipolar plate so that the flow groove ends and / or starts in the through-hole, in particular in the flow through-hole. In other words, the groove extends until it enters the flow through-hole or the through-hole. This makes it possible to achieve a particularly advantageous attachment of the flow groove in terms of flow technology. By providing a flow groove, it is particularly possible to achieve blockage of the fluid and also to achieve uniform delivery of the fluid to the MEA.

[0012] In a preferred embodiment, the flow channel is formed by straight and / or rectangular sections and / or the flow channel extends in a meandering manner. By using only straight and / or rectangular or right-angled sections and / or in a meandering design, the flow channel has a particularly large extension. This allows a particularly effective and uniform transport of the fluid into the MEA and / or the discharge of the fluid from the MEA into the flow channel. By means of the meandering design of the flow channel, in particular, a particularly long flow length of the channel can also be achieved, thereby achieving a particularly uniform transport or discharge of the fluid into and / or out of the MEA.

[0013] Advantageously, the portion of the outer contour of the perforation formed by the flow perforation is spaced further from the center of gravity of the perforation or the center point of the arc-shaped portion than the portion of the outer contour of the perforation formed by the mounting perforation. In other words, the flow perforation can extend away from the otherwise circular mounting perforation like a projection. Alternatively or additionally, preferably, the mounting perforation forms all the arc-shaped portions of the perforation and / or is formed only by arc-shaped portions, in particular all having the same center point. By this type of design of the perforation, some perforations, most of the perforations and / or all perforations, a particularly good fluid guiding feasibility can be achieved. The center point of the arc-shaped portion is in particular a point around which the radius of the arc-shaped portion is determined, or a point that has the same spacing from all points of the arc-shaped portion.

[0014] Preferably, the bipolar plate has a width-to-length ratio that is particularly less than or equal to 1 to 3, wherein the bipolar plate has a perforation, particularly a plurality of perforations, in its middle region along the longitudinal direction. In other words, the ratio of the size of the bipolar plate in the width direction to the size of the bipolar plate in the longitudinal direction can be less than or equal to 1 to 3. If such a ratio exists, a perforation, particularly a plurality of perforations, can be provided in the middle region along the longitudinal direction. The middle region along the longitudinal direction is particularly the following region of the bipolar plate along the longitudinal direction, which extends from the ideal center point in the longitudinal direction by + / -25%, preferably + / -15%, and particularly preferably + / -10% and more particularly preferably + / -5% of the maximum length of the bipolar plate along the longitudinal direction. The center point of the bipolar plate is particularly the volume center of gravity or center of gravity of the bipolar plate. By providing a perforation, particularly a plurality of perforations in the middle region, as described above and below, a particularly good tensioning feasibility of the bipolar plate can be achieved in particular. In particular, the bending moment caused by tensioning can be avoided or reduced by providing a perforation in the middle region. Advantageously, all of the passages are designed as described above or below, so that the passages have in particular a mounting passage and a flow passage, wherein in particular the connecting means are guided or can be guided through the flow passage.

[0015] Advantageously, the fuel cell comprises a sealing element, in particular a sealing ring. Suitably, the sealing element rests on the bipolar plate, wherein the sealing element at least partially follows or can follow the arc-shaped portion of the outer contour of the through-hole. Therefore, the fuel cell comprises in particular at least one sealing element, which can be configured as a sealing ring. A seal is understood as a sealing element that is closed in itself. In other words, the sealing ring is therefore a sealing element without ends. The sealing element rests in particular on the bipolar plate, which can occur in particular through direct contact between the sealing element and the bipolar plate. Suitably, the contact or contact area of ​​the sealing element and the bipolar plate constitutes a closed contour in itself. In other words, the sealing element can therefore always contact the bipolar plate along its extension. Suitably, the sealing element at least partially follows the arc-shaped portion or an arc-shaped portion of the outer contour of the through-hole. In particular, following is understood to mean that the projection of the sealing element and the projection of the outer contour onto a plane extending through the longitudinal direction and the width direction overlap, and / or the extent of the sealing element and the outer contour is identical at least in the following region, and / or the sealing element bears at least in sections against an arc-shaped portion of the outer contour. By such following of the sealing element in the arc-shaped circle of the outer contour of the feedthrough, it is possible in particular to achieve a particularly short length of the sealing element and also a high sealing effect.

[0016] In an advantageous embodiment, the sealing element follows at least 40%, preferably at least 60%, and particularly preferably at least 80%, and particularly preferably at least 90%, and more particularly preferably at least 97% of the arc-shaped portion of the outer contour of the perforation. Alternatively or additionally, the sealing element preferably follows at least 40%, preferably at least 60%, and particularly preferably at least 80%, and particularly preferably at least 90%, and more particularly preferably at least 97% of the outer contour of the perforation. By following at least 40% of the arc-shaped portion and / or the entire outer contour of the perforation, a particularly simple installation can be achieved. On the contrary, if at least 60% or at least 80% of the arc-shaped portion and / or the entire outer contour of the outer contour of the perforation is followed by the sealing element, a particularly good sealing effect can be achieved. On the contrary, if 90% of the outer contour or circular portion is followed by the sealing element, a particularly good mechanical support capability around the perforation can be achieved thereby. This capability is particularly noteworthy because when the bipolar plate is tensioned by means of a fastening structure or connecting mechanism guided through the perforation: the contact force or tensioning force can be reliably conducted directly via the sealing element. In particular, the arc-shaped portion of the outer contour of the through-hole or the outer contour of the through-hole following at least X percentage is understood to mean that at least X percentage of the projection of the outer contour of the arc-shaped portion or the entire outer contour onto a plane unfolded by the longitudinal direction and the width direction coincides with the projection of the sealing element in the plane, and / or the sealing element at least abuts against the arc-shaped portion of the outer contour or X percentage of the outer contour.

[0017] Advantageously, the sealing element projects into the perforation or into one perforation and / or into at least two perforations. In this case, in particular only the perforation is decisive, which has a mounting perforation and a flow perforation and / or through which the connecting means is led and / or which is used or designed to accommodate the connecting means. The projection makes it possible in particular for the seal to be arranged between the connecting means and the peripheral edge of the perforation, so that contact between the connecting means and the perforation is prevented. In other words, the sealing element can thus be used to bring about an electronic insulation between the connecting means and the bipolar plate.

[0018] The sealing element expediently consists, in particular, of an insulating material.

[0019] Advantageously, the fuel cell has a plurality of sealing elements, wherein the sealing elements at least partially follow the extension of the outer contour of at least one perforation and / or wherein each perforation is surrounded by the outer contour of the sealing element. Decisive for this are, in particular, perforations which have a mounting perforation and a flow perforation and / or which are designed to accommodate a connection mechanism. By virtue of the perforations and / or at least one of the perforations being surrounded by the outer contour of the sealing element, it can be achieved that the perforations can be used for conducting a fluid into and / or out of a fluid volume. In particular, a perforation being surrounded by the outer contour of the sealing element means that, when projected onto a plane formed by the longitudinal direction and the width direction of the surrounding sealing element and perforation, the projected outer contour of the sealing element or the outer edge of said contour surrounds and / or contains the outer contour of the perforation.

[0020] Preferably, the sealing element is fixed to the bipolar plate in a material-matched and / or irreversible manner, and / or the sealing element is manufactured by a screen printing method. The advantage of using a screen printing method is in particular the low-cost manufacture of the sealing element. By fixing the sealing element to the bipolar plate, in particular a simple installation of the fuel cell can be achieved. In order to achieve the fixing, the fixing is implemented in a material-matched manner, for example by bonding and / or by a screen printing method. Suitably, the sealing element is irreversibly fixed to the bipolar plate, so that the connection between the sealing element and the bipolar plate can only be achieved by destroying the connection. In this way, a particularly high sealing effect can be achieved.

[0021] Advantageously, the sealing element is arranged on the bipolar plate so that the sealing element forms a closed contour on the bipolar plate, wherein at least two flow perforations, especially different perforations and / or flow areas of the bipolar plate are advantageously arranged in the closed contour. By arranging the closed contour of the sealing element on the bipolar plate, a particularly high sealing effect can be achieved. By arranging at least two flow perforations in the closed contour, a particularly good delivery and export of the fluid to the sealed area can be achieved. In particular, the flow area of ​​the bipolar plate and / or at least the outlet or contour of the flow perforations, especially different perforations, are also arranged in the sealed area or in the closed contour. It is thus possible to achieve a particularly uniform or targeted delivery and export of the fluid to the flow area of ​​the bipolar plate.

[0022] In a preferred embodiment, the fuel cell includes a connecting mechanism, wherein the connecting mechanism guides through the through-hole, especially the installation through-hole of the through-hole, wherein the connecting mechanism especially contacts the sealing element. The insulation between the connecting mechanism and the bipolar plate can be achieved by the contact of the sealing element with the connecting mechanism. The connection mechanism is guided through the through-hole, especially the installation through-hole of the through-hole, and the tensioning and installation feasibility of the bipolar plate can be particularly simple and space-saving. Suitably, the connecting mechanism has an operating area, especially a head, and has an installation area, wherein the installation area constitutes a thread. Suitably, the installation area is formed in the rod area of ​​the connecting mechanism and / or around the rod area of ​​the connecting mechanism. The connecting mechanism extends in particular in the height direction. In other words, the main extension direction of the connecting mechanism is therefore advantageously formed parallel to the height direction. Particularly preferably, the connecting mechanism guides through each through-hole of the bipolar plate having an installation through-hole and a flow through-hole. It is thus possible to achieve a particularly uniform tensioning feasibility of the bipolar plate.

[0023] In a preferred embodiment, the connecting mechanism has a flow channel extending along a height direction or the height direction, wherein the flow channel is fluidly connected to the flow through-portion that together constitutes the through-portion, and the connecting mechanism guides through the through-portion. The flow channel can be a central recess, or the central recess can be a flow channel. For example, the connecting mechanism can be a Banjo joint, wherein the flow channel can be formed in the Banjo joint. Alternatively, the flow channel can also be preferably introduced into the connecting mechanism externally, for example, through an external groove. The flow channel extends in particular in the height direction. In other words, the flow channel can therefore provide a fluid conveying capacity in the height direction. In particular, the flow channel of the connecting mechanism is fluidly connected to the flow through-portion, so that the fluid can flow from the flow channel into the flow through-portion. A particularly effective flow feasibility can thus be provided. The flow channel can be realized in particular by means of one / the central recess of the connecting mechanism.

[0024] In an alternative or additionally preferred embodiment, the fuel cell comprises a plurality of connection means, wherein the plurality of connection means are led through a respective aperture, wherein the apertures in particular comprise mounting apertures and / or flow apertures. This makes it possible in particular to achieve a particularly uniform stress distribution, so that ultimately a particularly high sealing effect can be achieved, while at the same time valuable installation space can be saved.

[0025] Advantageously, the fuel cell comprises an end plate, wherein the end plate extends in one or said longitudinal direction and in one or said width direction, wherein the end plate has two tensioning areas that are apart from each other, in particular in the longitudinal direction, wherein the bending stiffness between the tensioning areas of the end plate, in particular, is variable, advantageously decreasing towards the tensioning areas. In particular, the end plate extends in the longitudinal direction and in the width direction, wherein the longitudinal direction of the end plate can correspond to the longitudinal direction described above and below, and / or the width direction can correspond to the width direction described above and below. The longitudinal direction of the end plate is in particular the direction in which the end plate has its largest main dimension, and / or the length of the end plate is determined in said direction. Conversely, the width direction is in particular the direction in which the width of the end plate is determined, and / or the end plate has its second largest main dimension in said direction. The longitudinal direction and the width direction can in particular be perpendicular to the height direction, wherein the height direction is in particular oriented parallel and / or coincident with the height direction described above and / or below. The end plate is in particular used for being arranged in a fuel cell, and in particular constituting the distal end of the fuel cell in the height direction. In order to achieve the installation of the end plate, the end plate has in particular two tensioning areas that are far away from each other. The tensioning area is in particular the following area, which is used to provide force transmission to the end plate. Preferably, the following area is provided between the two tensioning areas, in which the end plate has a variable bending stiffness. In particular, the area with variable bending stiffness is expanded here so that the area includes and / or constitutes a middle area in the longitudinal direction of the end plate. Here, the middle area of ​​the end plate is determined in the same way as the middle area of ​​the bipolar plate. Preferably, the bending stiffness of the area located between the tensioning areas is configured so that its bending stiffness decreases toward the tensioning areas. Therefore, the bending stiffness is the greatest in the area that is farthest away from the tensioning area in the longitudinal direction. Basically, the end plate is also called the top plate for the purposes of the present invention.

[0026] In an advantageous embodiment, the end plate has an arcuate reinforcing rib, wherein the arcuate reinforcing rib extends in particular parallel to the longitudinal direction. The arcuate reinforcing rib expediently has a variable height in the longitudinal direction. The arcuate reinforcing rib is designed in particular such that it has a largest main dimension parallel to the longitudinal direction, in order to thereby provide a particularly good absorption of bending stresses.

[0027] The end plate, in particular the clamping region of the end plate, expediently has a fixing aperture. It is particularly preferred that the connection extends through the fixing aperture, wherein the connection can in particular also extend through one or some of the apertures of the bipolar plate.

[0028] Advantageously, the connecting means are in particular screws or bolts.

[0029] Advantageously, the connecting mechanism comprises: an operating region, in particular a head; an elastic region; and preferably a mounting region, wherein the connecting mechanism extends in the extension direction, wherein the radial direction is in particular perpendicular to the extension direction, wherein the elastic region can be located between the operating region and the mounting region in the extension direction, wherein the mounting region has a thread, in particular an internal thread, wherein advantageously or optionally, the elastic region and / or the mounting region is or can be hollow inside, and / or wherein the elastic region has a smaller elasticity than the mounting region and / or than the operating region due to its geometry. The connecting mechanism is in particular used to connect different components to each other, in particular to each other in a force-fitting manner. The force-fitting connection in particular relates to transverse forces, advantageously in the radial direction or parallel to the direction. In order to be able to establish or transmit transverse forces, in particular perpendicular to the extension direction, between the components to be connected, the connecting mechanism is advantageously configured as a force-fitting connecting mechanism. The connecting mechanism in particular has an operating region. The operating region is advantageously used to be able to apply an installation torque, in particular in a form-fitting manner, to the connecting mechanism. For this purpose, the operating area can have an operating surface, in particular an operating surface in the form of an outer hexagonal edge, an inner hexagonal edge, an outer hexagonal circle or an inner hexagonal circle, multiple teeth and / or multiple wheels (Mehrrund), respectively, advantageously as an inner operating part and / or an outer operating part. Suitably, the normal of the operating surface points to the radial direction. Here, the operating surface can be a part of the head, and the head can constitute the operating area. In other words, the operating area can be formed by the head or include the head. Here, suitably, the operating area is configured so that the operating area constitutes the distal end of the connecting mechanism in the extension direction. The extension direction is also particularly the following direction in which the connecting mechanism has its largest main dimension. For example, the extension direction can therefore or alternatively preferably be the following direction in which the length of the connecting mechanism is measured. The extension direction is particularly oriented parallel to the height direction. The center of gravity of the connecting mechanism, the elastic region and / or the mounting region can be located in the extension direction. One or the radial direction extends particularly perpendicular to the extension direction. Advantageously, the extension direction, the radial direction and the circumferential direction constitute a cylindrical coordinate system with each other. The extension direction is particularly parallel to and / or coincides with the height direction. Here, the radial direction can be parallel to the width direction and / or the extension direction. In addition to the operating area, the connecting mechanism also has an elastic area and / or a mounting area. The mounting area of ​​the connecting mechanism has a thread so as to form a connection with another thread, in particular a nut thread. The thread can advantageously be configured as an internal thread so as to achieve a particularly space-saving configuration. Alternatively or additionally, it is preferred that the thread of the mounting area can also be an external thread. This allows particularly simple production. The thread itself can in turn be a metric or imperial thread. Preferably, the mounting area in the extension direction is limited by the distal end of the thread in the extension direction. Advantageously, the mounting area constitutes the distal end of the connecting mechanism in the extension direction.The mounting area with threads and / or formed by threads can limit the connection mechanism in the extension direction. In order to reduce the risk of injury during installation, the mounting area can be limited by a cylindrical surface pointing outward in the radial direction and / or have such a cylindrical surface. The elastic area is located between the operating area and the mounting area when viewed in the extension direction. It is advantageous that the length of the elastic area in the extension direction is greater than the length of the operating area and / or the mounting area in the extension direction. Here, the length of all areas in the extension direction is particularly measured. Suitably, the length of the elastic area in the extension direction is greater than the sum of the lengths of the operating area and the mounting area. Advantageously, at least 30%, preferably at least 60% and more preferably at least 70% of the length of the connection mechanism in the extension direction is formed by the elastic area. The elastic area and / or the mounting area are particularly hollow inside, so as to achieve and / or provide a simple installation and / or gas penetration and / or elasticity reduction. The elastic area is formed due to its geometry so that the elastic area has less elasticity than the mounting area, and / or wherein the elastic area has a deformation structure and / or a rigidity reduction structure in the form of a deformation structure. In other words, the geometry of the elastic region is implemented in particular so that a smaller elasticity is generated in the mounting region compared to the elasticity in the mounting region and / or the operating region. The elasticity itself is in particular the gradient of the spring rigidity or force-travel diagram. Here, the elasticity in the direction of the stretching direction is decisive for the elasticity. In particular, the force-travel diagram or spring rigidity is not dedimensionalized by geometric characteristic variables. In other words, the elasticity or spring rigidity is therefore not determined according to the gradient of the stress-strain diagram, but is determined according to the force actually applied to the elastic region compared to the synthetic displacement stroke or synthetic deformation. The force-travel diagram is therefore the following force, which must be applied in the stretching direction in order to separate the mounting region from the operating region, wherein the synthetic displacement stroke of the operating region relative to the mounting region along the stretching direction is recorded at the same time. Advantageously, the elastic region and the mounting region and / or the elastic region and the operating region are made of the same material and / or in one piece. It is thus possible to achieve particularly good mechanical retainability. Due to the lower elasticity of the elastic region (due to the geometry in the elastic region and / or due to the rigidity-reducing structure), the loads (caused by the increased and / or static expansion of the components to be connected) can be reduced. In particular, the loads acting on the connection and / or on the components to be tensioned or tensioned can be reduced as a result, so that the operational safety and durability of the connection can be increased. Another advantage of this design is that in particular also the dynamic loads acting on the connection are reduced.

[0030] Advantageously, the elastic region has one or more deformation structures which are subjected to bending and / or torsion when the actuating region is displaced relative to the mounting region in the extension direction. The deformation structures are in particular spirals or beam sections which can be realized, for example, by introducing recesses and / or through-holes or other rigidity-reducing structures in the elastic region, in particular in the radial direction. The deformation structures are therefore in particular not recesses but material regions which are subjected to mechanical loads due to a change in length in the extension direction of the elastic region, in particular due to a displacement of the mounting region relative to the actuating region in the extension direction. The mechanical loads of the deformation structures are in particular or in particular comprise bending loads and / or torsion loads. The load types are in particular the dominant load types, and thus in particular the load types which cause at least 30%, preferably at least 50% and particularly preferably at least 70% of the equivalent stress, in particular when applying the (von Mises) configuration change assumption and / or the (Rankine) principal normal stress assumption. In this way, in particular, the achievable reversible degree of deformation of the deformation structure can be increased, so that the elasticity of the final elastic region can be reduced. In other words, the spring stiffness of the elastic region, which can be a synonym for elasticity, is reduced by using a deformation structure, which is subjected to bending and / or torsion when the actuating region is displaced in the extension direction relative to the mounting region. In this way, in particular, a particularly advantageous design of the elastic region can be achieved.

[0031] Advantageously, the elastic region is designed in such a way that it has a decreasing spring characteristic. In other words, the elasticity or spring stiffness of the elastic region (with respect to the displacement of the actuating region relative to the mounting region in the extension direction) can be realized in such a way that the elasticity decreases or falls as the spacing of the actuating region relative to the mounting region in the extension direction increases. It can thereby be achieved, in particular, that the dynamic loads can be further reduced when the expansion of the component to be connected increases, or that the (static) loads generated thereby do not increase as strongly. Advantageously, the spring characteristic is decreasing in the elastic region. In other words, a decreasing spring characteristic is thus achieved, in particular “before” an irreversible deformation occurs. In this way, in particular, a permanent load relief and / or mechanical overload of the component to be connected and / or the connecting mechanism can be minimized and / or reduced.

[0032] Advantageously, the elastic region has one or more rigidity-reducing structures, in particular depressions and / or perforations, wherein the rigidity-reducing structures form or delimit the deformation structure. In other words, in the elastic region, in particular in the radial direction, depressions and / or further rigidity-reducing structures can be formed, which respectively border the deformation structure. In particular, the depressions can be designed in this case so that a fluid can pass through them from the surroundings via the depressions or depressions or perforations into the internal hollow region or the internal hollow elastic region in general. In other words, one or more perforations can be designed so that they extend from the outside until they enter the internal hollow region of the elastic region.

[0033] The or one of the internally hollow regions of the connection means can in particular be formed by a central recess which extends in the extension direction from the mounting region into the elastic region or even into the actuation region. Thus, by providing such a central recess, a fluid flow can also be achieved between the individual regions of the connection means in the extension direction.

[0034] Advantageously, the rigidity-reducing structure, in particular in the form of one or more recesses, connects an outer wall of the elastic region to an inner wall of the elastic region. The outer wall of the elastic region borders the elastic region outwardly, in particular in a positive radial direction, while the inner wall borders the elastic region inwardly in the direction of extension. In this case, the inner wall can in particular border the central recess and / or be partially formed together. As a result, a fluid flow from the surroundings into the inner hollow region of the elastic region can be achieved in a particularly efficient and direct manner (as already explained).

[0035] Advantageously, at least one rigidity reducing structure, in particular a rigidity reducing structure in the form of a recess, is designed so that its projection in the extension direction itself overlaps. In other words, at least one recess can be designed so that when the recess is projected onto a plane perpendicular to the extension direction, the projection itself is closed and can in particular form a ring around the extension direction. In this way, a particularly large reduction in elasticity can be achieved, so that a particularly advantageous elastic region is produced. However, advantageously, the ends of the recesses that form the projections that overlap themselves or are closed themselves are located at different heights in the extension direction. In other words, in particular, the recess of the through-hole is only closed in the projection itself and is not closed when the recess is observed taking into account the extension in the extension direction. In this way, a severe weakening of the connection mechanism can be prevented in particular.

[0036] Advantageously, the elastic region has one or more helical recesses, in particular through-holes, and / or rigidity-reducing structures, so that the elastic region has one or more and / or multi-headed deformation structures, which are helical portions. By providing a helical recess, which can in particular be a through-hole, and / or a rigidity-reducing structure, it can be achieved in a particularly efficient manner that the deformation structure withstands torsion. By providing a deformation structure that withstands torsion, a particularly high degree of reversible deformation capability can be provided. By providing a helical deformation structure, it is possible to achieve particularly good torsion resistance. As already explained, it is also possible to provide multiple helices so that there can be a multi-headed deformation structure in the shape of a helix. In other words, the helical multi-headed deformation structure can be formed similarly to a multi-thread thread.

[0037] Advantageously, the deformation structure, in particular the spiral portion, has a material strength in the direction of extension and a material strength in the radial direction (which can also be referred to as radial strength), wherein the ratio of material strength to radial strength is in the range of 0.8 to 1.2, preferably in the range of 0.9 to 1.1, and particularly preferably in the range of 0.97 to 1.03. Therefore, the material strength is the average and / or maximum or minimum material strength of the deformation structure measured in the extension direction. The radial strength of the deformation structure is in particular the material strength or material thickness in the radial direction. Advantageously, the ratio of material strength to radial strength is in the range of 0.8 to 1.2. This allows particularly simple production. On the other hand, if the material strength is in the range of 0.9 to 1.1, a particularly advantageous stress distribution can be achieved. On the other hand, if the ratio is in the range of 0.97 to 1.03, an approximately uniform stress distribution can be achieved at all edges.

[0038] Advantageously, at least one recess and / or rigidity reducing structure, preferably a plurality of recesses and / or rigidity reducing structures are in the form of an elongated hole. Preferably, the or at least one, preferably at least a major part, and particularly preferably all of the elongated hole-shaped rigidity reducing structures and / or recesses are designed as a perforation. In particular, a recess / rigidity reducing structure is considered to be elongated hole-shaped if the dimension of the recess / rigidity reducing structure in its main extension direction is greater than the dimension perpendicular to the main extension direction. In other words, therefore, an elongated hole-shaped recess or an elongated hole-shaped perforation can exist when the length in the circumferential direction of the perforation is greater than the length of the perforation in the extension direction. In this case, in particular, the length of the perforation and / or recess in the radial direction is unimportant. In other words, therefore, in particular for the elongated hole form, only the contour left by the recess and / or perforation on the outer wall of the elastic region is decisive. Suitably, the elongated hole-shaped perforation or the elongated hole-shaped recess has a greater extension, in particular in the circumferential direction, than in the extension in the extension direction. Advantageously, the extension in the circumferential direction is at least 10%, preferably at least 20% and particularly preferably at least 30% greater than the extension in the extension direction in order to define the elongated hole shape. Advantageously, the distal end region of the elongated hole-shaped passage or the elongated hole-shaped recess is formed by a rounding. This allows the occurrence of material overstress or overstress factors to be reduced.

[0039] Preferably, the projection of the oblong hole-shaped recess or the rigidity-reducing structure in the direction of extension, in particular, forms a closed circle in the direction of extension. In other words, the projection of the oblong hole-shaped recess, which can in particular be a through-hole, is thus formed such that when viewed in the direction of extension, the projections overlap to form a complete circle or an inherently closed ring, wherein in particular the center of gravity of the ring lies in the direction of extension and / or the ring surrounds the direction of extension. In this way, a particularly advantageous reduction in the elasticity of the elastic region can be achieved.

[0040] Preferably, at least one elongated hole-shaped rigidity reducing structure and / or recess has a variable width in the extension direction and / or in the longitudinal direction. Here, the width is in particular the spacing of the opposite wall portions in the extension direction and / or in the longitudinal direction. In particular, that is to say, the elongated hole or the elongated hole-shaped recess is oriented so that it extends perpendicular to the extension direction. In other words, the main extension direction is therefore oriented perpendicular to the extension direction and / or perpendicular to the longitudinal direction in the projection in the radial direction. Through the variable width in the extension direction and / or in the longitudinal direction, a defined stress distribution can be achieved in particular. Advantageously, the width of the elongated hole-shaped through-hole or recess decreases toward the center of the recess or through-hole. In other words, the width of the recess can first decrease from the distal end of the through-hole or recess toward the other distal end of the recess and increase again after exceeding the center between the distal ends of the recess. It is thereby possible to achieve particularly advantageous mechanical stresses that are expected to occur. In other words, a particularly stress-matched variation process can thereby be achieved.

[0041] Advantageously, the deformation structure, in particular the deformation structure arranged between two oblong hole-shaped perforations, has a material strength in the direction of extension, in particular a maximum material strength, and a material strength in the radial direction, in particular a maximum material strength, which (as already shown) can be referred to as radial strength, wherein the ratio of material strength to radial strength is in the range of 0.7 to 1.3, preferably in the range of 0.85 to 1.15 and particularly preferably in the range of 0.9 to 1.1. The material strength (as already shown) is in particular the average and / or maximum or minimum material strength of the deformation structure measured in the direction of extension. The radial strength of the deformation structure (as also already shown) is in particular the material strength or material thickness in the radial direction.

[0042] Advantageously, the ratio of material strength to radial strength is in the range of 0.7 to 1.3. This allows particularly cost-effective production, in particular when the deformation structure is at least partially limited in the extension direction by the elongated hole-shaped passage. If, on the other hand, the material strength is in the range of 0.85 to 1.15, particularly low local stress concentrations can be achieved, in particular when the deformation structure is at least partially limited in the extension direction by the elongated hole-shaped passage. If, on the other hand, the ratio is in the range of 0.9 to 1.1, a particularly good increase in elasticity can be achieved.

[0043] Advantageously, the ratio of the average height or maximum height of the perforation, in particular the perforation in the form of an elongated hole, in the direction of extension to the diameter of the elastic region is in a ratio of 0.045 to 0.125, preferably in a range of 0.055 to 0.0834, particularly preferably in a range of 0.06 to 0.75. Here, the average height or maximum height of the perforation in the direction of extension is the width of the perforation in the direction of extension, in particular between two walls that are opposite in the direction of extension. In contrast, the average height is the average height of the perforation along the direction of extension from one distal end to the other distal end. In contrast, the diameter of the elastic region is the diameter of the smallest possible circle that can just enclose the elastic region in a plane perpendicular to the direction of extension. Here, if the ratio is in a range of 0.045 to 0.125, a particularly effective elasticity reduction can be achieved thereby. In contrast, if the ratio is in a range of 0.055 to 0.0834, a particularly simple production can be achieved thereby.

[0044] Advantageously, the connecting mechanism is formed in one piece. In particular, the one-piece formation is understood to mean that the materials of the connecting mechanism are connected to each other in a single initial forming process. In other words, although the connecting mechanism can be further processed after the forming process, in particular by separation or segmentation methods such as laser cutting and / or thread cutting and / or milling or turning, other elements are not added to the connecting mechanism, for example, by welding. However, advantageously, only the operating area, the elastic area and the mounting area are formed in one piece with each other. Alternatively or additionally, it is preferred that the connecting mechanism can also be produced by materially bonding other components to each other, in particular by materially bonding the operating area with the elastic area and the mounting area. In addition, in the materially bonded connection, other elements can also be installed on the connecting mechanism, so that the following connecting mechanism is finally produced, wherein the operating area, its elastic area and its mounting area are bonded to each other by materially bonding, but wherein other elements can be fastened to the connecting mechanism in a force-fitting manner and / or a shape-fitting manner and / or a materially bonding manner. Materially bonding is particularly advantageous in terms of production costs. In contrast, in a particularly mechanically advantageous embodiment, the connecting means and / or the actuating region are / is formed in one piece with the elastic region and the mounting region.

[0045] Advantageously, the operating region is hollow, in particular hollow inside. As a result, a fluid flow can flow through the elastic region and / or the mounting region, in particular in the hollow region of the operating region. As a result, the connection described here can be used particularly advantageously in a fuel cell. In this context, hollow is understood to mean, in particular, that the entire operating region can be hollow in the extension direction.

[0046] Advantageously, the operating area has a gas connection. As a result, a gas flow out of the operating area and / or into the operating area can be realized particularly easily. The gas connection can in particular have or form a gas-tight thread and / or a hose connection.

[0047] Advantageously, there is a central recess which extends in the extension direction from the operating region via the elastic region and can reach the mounting region. Advantageously, the central recess extends from the distal end of the mounting region to the distal end of the operating region. In other words, the central recess can extend through the connecting means in the extension direction, so as to thereby in particular enable a fluid flow through the connecting means. Advantageously, the central recess has a constant diameter in the operating region, the elastic region and / or the mounting region. This allows particularly simple and cost-effective production, which also has mechanically advantageous properties.

[0048] The actuation region expediently has an actuation surface, wherein the actuation surface has a normal in particular in the radial direction. Thus, for mounting the connection, a torque, in particular a form-fitting torque, can be applied to the connection in a simple manner, in particular about the extension direction. The arrangement in which the normal of the actuation surface points in the radial direction makes it possible to achieve particularly advantageous production, which can also be easily operated.

[0049] Advantageously, one or more depressions and / or perforations, in particular depressions and / or perforations formed in the form of spirals and / or slots, are laser cut, thereby resulting in particularly cost-effective and precise production, making it possible to avoid and / or reduce local (unwanted) stress concentrations.

[0050] A further aspect of the invention can relate to the use of a connecting mechanism in / for a fuel cell as described above and / or below.

[0051] Another aspect of the invention can relate to the use of a bipolar plate and / or a bipolar plate system as described above and / or hereinafter in / for a fuel cell as described above and / or hereinafter.

[0052] An additional aspect of the invention can relate to the use of an end plate as described above and / or hereinafter in / for a fuel cell as described above and / or hereinafter.

[0053] Suitably, the fuel cell comprises at least one bipolar plate, preferably a plurality of bipolar plates, in particular bipolar plates as described above and / or below. Alternatively or additionally preferably, the fuel cell can also involve one or more connecting means and / or sealing elements, in particular connecting means and / or sealing elements as described above and / or below. Furthermore, alternatively or additionally preferably, the fuel cell can also have at least one end plate or two end plates, in particular end plates as described above and / or below.

[0054] In a preferred embodiment of the fuel cell, a cavity is formed between and / or in two bipolar plates, which cavity is partially delimited by a flow region of one or both bipolar plates, wherein a fluid reaches or can reach the cavity through one of the perforations of the bipolar plate, in particular through the flow perforation, and / or wherein a fluid leaves / can leave the cavity through one of the perforations of the bipolar plate, in particular through the flow perforation. In other words, the flow region of the bipolar plate can thus be fluidically connected to the flow perforation of one perforation and the flow perforation of another perforation. This makes it possible to achieve a particularly effective and simple possibility of contacting the fluid with the flow region via the flow perforation.

[0055] In a preferred development, the MEA is arranged in the cavity. MEA is understood here as a membrane electrode unit. This allows a particularly compact design of the fuel cell to be achieved.

[0056] Another aspect of the present invention can relate to a method for producing a connecting mechanism, in particular a connecting mechanism as described above and below. The method comprises in particular the following steps:

[0057] Advantageously providing a blank;

[0058] The operating area, in particular the head, is advantageously formed by shaping;

[0059] Forming, in particular by means of shaping, an in particular hollow mounting region;

[0060] Forming the elastic region, in particular by introducing a rigidity-reducing structure, advantageously in the form of a depression and / or a through-hole, between the actuating region and the mounting region along the extension direction.

[0061] The introduction of the rigidity-reducing structure can be carried out in particular by means of a laser, thus for example by laser cutting. The connecting means provided by the method for production can in particular have the features, designs, embodiments and advantages described above and below. In particular, the actuating region and / or the elastic region and / or the mounting region are formed by a shaping method in this case, in order to thereby achieve a particularly mechanically load-bearing and yet cost-effective design of the connecting means. The connecting means can in particular be screws and / or bolts. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Further advantages and features of the invention emerge from the following description with reference to the drawings. Individual features of the illustrated embodiments can also be used in other embodiments, unless this is explicitly excluded.

[0063] The accompanying drawings show:

[0064] Figure 1 A bipolar plate is shown;

[0065] Figure 2 A fuel cell and / or bipolar plate is shown;

[0066] Figure 3 A view showing an alternative design of a bipolar plate;

[0067] Figure 4 A fuel cell having a bipolar plate and a connection mechanism is shown;

[0068] Figure 5 A fuel cell having an end plate and a plurality of bipolar plates is shown;

[0069] Figure 6 showing an isometric view of the end plate;

[0070] Figure 7 A side view showing a connection mechanism having a rigidity reducing structure in the shape of an elongated hole;

[0071] Figure 8 Likewise shown is a connection mechanism having a rigidity-reducing structure as a recess, wherein the width of the rigidity-reducing structure decreases towards the center;

[0072] Fig. 9 A sub-view showing a connection mechanism in a fuel cell;

[0073] Fig.10 A plurality of connection mechanisms in a fuel cell are shown;

[0074] Fig.11 side and cross-sectional views showing the connection mechanism; and

[0075] Fig.12 A connection mechanism having a deformed structure of a spiral portion is shown. DETAILED DESCRIPTION

[0076] exist Figure 1An isometric view of the bipolar plate 210 is shown in FIG. The bipolar plate 210 has a plurality of perforations 240 extending in a height direction H. The perforations include mounting perforations 242 and flow perforations 244, respectively. The mounting perforations 242 each have an arc-shaped portion and / or an arc-shaped portion constituting the outer contour of the perforation 240. The mounting perforations 242 are configured to accommodate a connecting mechanism, and the bipolar plate has a width-to-length ratio of less than or equal to 1 to 3, wherein a plurality of perforations 240 are arranged in the bipolar plate 210 in a central region along the longitudinal direction L. This enables a particularly uniform tension distribution on the bipolar plate 210 to be formed.

[0077] exist Figure 2 , an isometric view of bipolar plates 210 can be seen, which are arranged one above the other in the height direction H. A sealing element 310 is arranged between the bipolar plates 210. In other words, Figure 2 A bipolar plate system 300 can also be seen in the figure, which can include a bipolar plate 210 and a sealing element 310. The bipolar plate system is part of the present invention and can be applied to the bipolar plate according to the present invention. This situation is irrelevant to the embodiment. As can be seen from the highest bipolar plate 210 in the height direction H, a plurality of sealing elements 310 are fixed to the bipolar plate. The sealing elements 310 surround the perforations 240 respectively. Each of the perforations 240 includes at least one mounting perforation 242 and a flow perforation 244. The sealing element 310 follows at least 60% of the arc-shaped portion of the outer contour of each perforation 240. The arc-shaped portion of the mounting perforation 242 constitutes at least 65% of the circle of the corresponding perforation 240. The flow perforation 244 is configured here so that the flow perforation is configured in a manner pointing to the flow area 252. The flow area 252 is also surrounded by the sealing element 310. Each sealing element 310 here at least partially extends into one or both penetrations 240, ie at least partially into the mounting penetration 242. This makes it possible to achieve particularly good insulation capabilities for the connecting means 9 that can be accommodated in the mounting penetration 244, such as in Figure 4 As shown in .

[0078] exist Figure 3 , a view of a bipolar plate 210 is shown, wherein the bipolar plate 210 has six perforations 240 extending in the height direction H. The width direction B and the longitudinal direction L are perpendicular to the height direction H. A flow groove 250 extends from a perforation 240 arranged at the lower left to a perforation 240 arranged at the upper right, which flow groove leads through a flow region 252. The flow groove 250 is arranged in a meandering shape here.

[0079] The flow region 252 is surrounded by a sealing element 310 , which also surrounds the two passages 240 .

[0080] exist Figure 4 1 shows a fuel cell 1 or a part of a fuel cell 1, in particular a bipolar plate system 300, which includes a plurality of sealing elements 310 and a plurality of bipolar plates 210 and a connecting mechanism 9. The connecting mechanism 9 extends in the height direction H. Figure 4 As can be seen in the figure, a plurality of sealing elements 310 contact the bipolar plate 210 and the connecting means 9. The connecting means 9 is designed in this case so that it has a flow channel extending in the height direction H, wherein the flow channel is fluidically connected to the flow passage 244 of the corresponding passage 240. As a result, a particularly good and advantageous fluid supply and / or discharge can be performed through the connecting means 9.

[0081] exist Figure 5 2 shows a fuel cell 1 , wherein the fuel cell 1 has a plurality of connecting means 9 and a plurality of bipolar plates 210 and / or bipolar plate systems 300 . The fuel cell 1 is delimited in the height direction H at least in sections by end plates 500 .

[0082] exist Figure 6 , an end plate 500 is shown. The end plate 500 extends in a longitudinal direction L and in a width direction B, wherein the end plate 500 has tensioning regions 502 that are spaced apart from one another in the longitudinal direction L, wherein fastening apertures 510 are provided in the tensioning regions 502. The tensioning regions 502 are arranged such that they each have at least three fastening apertures 510. Between the tensioning regions 502, in particular when viewed in the longitudinal direction L, the bending stiffness of the end plate 500 is variable, wherein the bending stiffness decreases toward the tensioning regions 502. The variable bending stiffness can be achieved here by reinforcing ribs 520 that extend parallel to the longitudinal direction L.

[0083] exist Figure 7 , the connecting means 9 is shown, which has an operating area 10 in the form of a head. The operating area 10 has a connecting thread for a gas connection. In addition, the connecting means 9 also has a mounting area 50, wherein the fastening area 10 and the mounting area 50 constitute end areas of the fastening means / connecting means 9 that are opposite to each other at the distal end in the extension direction V. The elastic area 30 is located between the fastening area 10 and the mounting area 50. Due to its geometry, the elastic area 30 has a smaller elasticity than the mounting area 50 and smaller elasticity than the operating area 10, and the elastic area 30 has a decreasing spring characteristic. The rigidity characteristics of the elastic area 30 are achieved by a rigidity reduction structure that is formed as a long hole-shaped through-portion.

[0084] exist Figure 8 Shown in Figure 7Compared to the similar fastening / connecting means 9. However, the actuating region 10 has an outer hexagon with an actuating face 12. An internal thread for mounting is present in the mounting region 50 which is hollow inside. The radial direction R points radially from the extension direction V. The deformation structure 32 present in the elastic region 30 is realized such that it has a variable width in the extension direction V, wherein the width decreases towards the center of the recess.

[0085] exist Fig. 9 A detailed view of the fastening device 9 installed in the fuel cell can be seen in FIG. The operating region 10 with the operating surface 12 in its interior and the elastic region 30 are both provided with a central recess 60, so that an internal hollow region is generated both in the elastic region 30 and in the operating region 10. The rigidity reducing structure is designed in the form of an elongated hole. The rigidity reducing structure 34 forms a deformation structure 32, wherein the deformation structure 32 has a radial strength RS in the radial direction R.

[0086] exist Fig.10 , a fuel cell is shown with a plurality of connecting means 9. The connecting means 9 here completely penetrate the fuel cell 9 in each case in the extension direction V or the height direction H. Basically, the connecting means 9 or the extension direction V should be parallel to the longitudinal direction L or the height direction H here.

[0087] exist Fig.11 , a side view is shown in the lower region and a sectional view through the connecting means 9 is shown in the upper region. The connecting means 9 extends in the extension direction V. In this case, deformation structures 32 are formed in the elastic region 32, which are connected one after another in the manner of a disc spring. Due to the geometrical design, the elastic region 30 has a decreasing spring characteristic. The radial strength RS in the elastic region can be seen here. Both the mounting region 50 and the elastic region 30 are hollow inside and thus each have a section of a central recess 60. In order to enable the mounting of the connecting means 9, the mounting region 50 has an internal thread.

[0088] exist Fig.12 . The connecting means 9 has a deformation structure 32, which is a spiral. In other words, the elastic region 30 has a helical depression, which forms the deformation structure 32. The deformation structure 32 has a material strength MS in the extension direction V. Alternatively, it is preferred that instead of a helical depression, multiple helical depressions can also be provided, so that one or more multi-start deformation structures in the form of a spiral are generated. The mounting region 50 also has a metric internal thread.

[0089] Reference numerals list

[0090] 1. Fuel Cell

[0091] 9Connection mechanism

[0092] 10 Operation area, especially the head

[0093] 12 Operation surface

[0094] 30 elastic areas

[0095] 32Deformation structure

[0096] 34 Rigidity reduction structure, recessed part, especially through-hole part

[0097] 50Installation area

[0098] 60 central recess

[0099] 210 Bipolar Plate

[0100] 240 Pass-through

[0101] 242 Install the feedthrough

[0102] 244 Flow through

[0103] 250 Flow Cell

[0104] 252 Flow Area

[0105] 300 Bipolar Plate System

[0106] 310 Sealing element

[0107] 500 End Plate

[0108] 502 tension area

[0109] 510 Fixed through-hole

[0110] 520 reinforcement rib

[0111] BWidth direction

[0112] L Longitudinal direction

[0113] HHeight direction

[0114] V stretch direction

[0115] MS Material Strength

[0116] R radial direction

[0117] RS radial strength

[0118] U Circumferential direction

Claims

1. A fuel cell (1), comprising a bipolar plate (201), in particular a plurality of bipolar plates (210), and / or comprising a connecting mechanism (9), in particular a plurality of connecting mechanisms (9), wherein the bipolar plate (210) extends in a longitudinal direction (L) and in a width direction (B), wherein the longitudinal direction (L) and the width direction (B) are in particular perpendicular to each other, The bipolar plate (210) has a plurality of through-holes (240), wherein the through-holes (240) have an outer contour, wherein the outer contour of the aperture (240) is in particular formed by a mounting aperture (242) and at least one flow aperture (244), The mounting through-hole (242) advantageously constitutes an arc-shaped portion of the outer contour of the through-hole (240), and The installation aperture (242) or the aperture (240) is designed to accommodate the connecting means or a connecting means (9).

2. The fuel cell (1) according to claim 1, The arc-shaped portion of the installation aperture (242) forms at least 51%, preferably at least 65% and particularly preferably at least 75% of the circle.

3. The fuel cell (1) according to any one of the preceding claims, wherein the arc-shaped portion of the mounting aperture (242) constitutes a maximum of 98%, preferably a maximum of 90%, and particularly preferably a maximum of 80% of the circle.

4. A fuel cell (1), comprising a sealing element (310), in particular a sealing ring, The sealing element (310) is in contact with the bipolar plate (210). The sealing element (310) at least partially follows the arc-shaped portion of the outer contour of the aperture (240).

5. The fuel cell (1) according to claim 4, The sealing element (310) projects into the aperture (240) or into at least two apertures (240).

6. The fuel cell (1) according to any one of claims 4 to 5, wherein the sealing element (310) is in particular materially bonded and / or reversibly fastened to the bipolar plate (210), and / or The sealing element (310) is manufactured by a screen printing method or by on-site molding.

7. The fuel cell (1) according to any one of claims 4 to 6, The sealing element (310) is arranged on the bipolar plate (210) such that the sealing element (310) forms a self-closed contour on the bipolar plate (210). In this case, at least two flow passages (244), in particular different passages (240), and / or flow regions (252) of the bipolar plate (210) are arranged within the closed contour.

8. A fuel cell (1) according to any one of the preceding claims, The connecting mechanism (9) comprises: an operating area (10), in particular a head; an elastic area (30); and a mounting area (50), The connecting mechanism (9) extends in the extension direction (V), The radial direction (R) is in particular perpendicular to the extension direction (V), The elastic region (30) is located between the operating region (10) and the mounting region (50) in the extension direction (V). wherein the mounting area (50) has a thread, in particular an internal thread, The elastic region (30) and / or the mounting region (50) are particularly hollow inside. wherein the elastic region (30) has a rigidity-reducing structure (34), in particular a rigidity-reducing structure in the form of a recess and / or a through-hole, and / or wherein the elastic region (30) has a smaller elasticity than the mounting region (50) and / or a smaller elasticity than the operating region (10) due to its geometry, and / or The elastic region (30) has a decreasing spring characteristic.

9. A fuel cell (1) according to any of the preceding claims, in particular according to claim 8, The elastic region (30) has one or more deformation structures (32) which are subjected to bending and / or torsion when the operating region (10) is displaced relative to the mounting region (50) along the extension direction (V).

10. The fuel cell (1) according to any of the preceding claims, in particular according to claim 8 or 9, The elastic region (30) has a decreasing spring characteristic.

11. The fuel cell (1) according to any of the preceding claims, in particular according to any of claims 8 to 10, At least one depression (34), preferably a plurality of depressions (34), is in the form of an elongated hole.

12. The fuel cell (1) according to any of the preceding claims, in particular according to any of claims 8 to 11, There is a central recess (60) which extends in an extension direction (V) from the actuating region (10) via the elastic region (30) to the mounting region (50), in particular to the distal end of the mounting region (50).

13. A fuel cell (1) according to any one of the preceding claims, wherein the connecting means (9) is guided through the through-hole (240), in particular through the mounting through-hole (242) of the through-hole (240), The connecting mechanism (9) contacts the sealing element (310) or one of the sealing elements (310).

14. The fuel cell (1) according to any of the preceding claims, in particular according to claim 13, The connecting mechanism (9) has a central recess (60) and / or a flow channel extending along a height direction (H), The flow channel and / or the central recess (60) are fluidically connected to the flow passage (244), which together form the passage (240) through which the connecting means (9) passes.

15. Use of a bipolar plate (210) and / or a bipolar plate system (300) in a fuel cell (1) according to any one of the preceding claims, and / or use of a connecting mechanism (9) in a fuel cell (1) according to any one of the preceding claims.

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